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linux/fs/btrfs/volumes.c
Qu Wenruo 726a342120 btrfs: relocation: add error injection points for cancelling balance 
Introduce a new error injection point, should_cancel_balance().

It's just a wrapper of atomic_read(&fs_info->balance_cancel_req), but
allows us to override the return value.

Currently there are only one locations using this function:

- btrfs_balance()
  It checks cancel before each block group.

There are other locations checking fs_info->balance_cancel_req, but they
are not used as an indicator to exit, so there is no need to use the
wrapper.

But there will be more locations coming, and some locations can cause
kernel panic if not handled properly.  So introduce this error injection
to provide better test interface.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:54 +01:00

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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2007 Oracle. All rights reserved.
*/
#include <linux/sched.h>
#include <linux/bio.h>
#include <linux/slab.h>
#include <linux/blkdev.h>
#include <linux/ratelimit.h>
#include <linux/kthread.h>
#include <linux/raid/pq.h>
#include <linux/semaphore.h>
#include <linux/uuid.h>
#include <linux/list_sort.h>
#include "misc.h"
#include "ctree.h"
#include "extent_map.h"
#include "disk-io.h"
#include "transaction.h"
#include "print-tree.h"
#include "volumes.h"
#include "raid56.h"
#include "async-thread.h"
#include "check-integrity.h"
#include "rcu-string.h"
#include "dev-replace.h"
#include "sysfs.h"
#include "tree-checker.h"
#include "space-info.h"
#include "block-group.h"
#include "discard.h"
const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
[BTRFS_RAID_RAID10] = {
.sub_stripes = 2,
.dev_stripes = 1,
.devs_max = 0, /* 0 == as many as possible */
.devs_min = 4,
.tolerated_failures = 1,
.devs_increment = 2,
.ncopies = 2,
.nparity = 0,
.raid_name = "raid10",
.bg_flag = BTRFS_BLOCK_GROUP_RAID10,
.mindev_error = BTRFS_ERROR_DEV_RAID10_MIN_NOT_MET,
},
[BTRFS_RAID_RAID1] = {
.sub_stripes = 1,
.dev_stripes = 1,
.devs_max = 2,
.devs_min = 2,
.tolerated_failures = 1,
.devs_increment = 2,
.ncopies = 2,
.nparity = 0,
.raid_name = "raid1",
.bg_flag = BTRFS_BLOCK_GROUP_RAID1,
.mindev_error = BTRFS_ERROR_DEV_RAID1_MIN_NOT_MET,
},
[BTRFS_RAID_RAID1C3] = {
.sub_stripes = 1,
.dev_stripes = 1,
.devs_max = 3,
.devs_min = 3,
.tolerated_failures = 2,
.devs_increment = 3,
.ncopies = 3,
.nparity = 0,
.raid_name = "raid1c3",
.bg_flag = BTRFS_BLOCK_GROUP_RAID1C3,
.mindev_error = BTRFS_ERROR_DEV_RAID1C3_MIN_NOT_MET,
},
[BTRFS_RAID_RAID1C4] = {
.sub_stripes = 1,
.dev_stripes = 1,
.devs_max = 4,
.devs_min = 4,
.tolerated_failures = 3,
.devs_increment = 4,
.ncopies = 4,
.nparity = 0,
.raid_name = "raid1c4",
.bg_flag = BTRFS_BLOCK_GROUP_RAID1C4,
.mindev_error = BTRFS_ERROR_DEV_RAID1C4_MIN_NOT_MET,
},
[BTRFS_RAID_DUP] = {
.sub_stripes = 1,
.dev_stripes = 2,
.devs_max = 1,
.devs_min = 1,
.tolerated_failures = 0,
.devs_increment = 1,
.ncopies = 2,
.nparity = 0,
.raid_name = "dup",
.bg_flag = BTRFS_BLOCK_GROUP_DUP,
.mindev_error = 0,
},
[BTRFS_RAID_RAID0] = {
.sub_stripes = 1,
.dev_stripes = 1,
.devs_max = 0,
.devs_min = 2,
.tolerated_failures = 0,
.devs_increment = 1,
.ncopies = 1,
.nparity = 0,
.raid_name = "raid0",
.bg_flag = BTRFS_BLOCK_GROUP_RAID0,
.mindev_error = 0,
},
[BTRFS_RAID_SINGLE] = {
.sub_stripes = 1,
.dev_stripes = 1,
.devs_max = 1,
.devs_min = 1,
.tolerated_failures = 0,
.devs_increment = 1,
.ncopies = 1,
.nparity = 0,
.raid_name = "single",
.bg_flag = 0,
.mindev_error = 0,
},
[BTRFS_RAID_RAID5] = {
.sub_stripes = 1,
.dev_stripes = 1,
.devs_max = 0,
.devs_min = 2,
.tolerated_failures = 1,
.devs_increment = 1,
.ncopies = 1,
.nparity = 1,
.raid_name = "raid5",
.bg_flag = BTRFS_BLOCK_GROUP_RAID5,
.mindev_error = BTRFS_ERROR_DEV_RAID5_MIN_NOT_MET,
},
[BTRFS_RAID_RAID6] = {
.sub_stripes = 1,
.dev_stripes = 1,
.devs_max = 0,
.devs_min = 3,
.tolerated_failures = 2,
.devs_increment = 1,
.ncopies = 1,
.nparity = 2,
.raid_name = "raid6",
.bg_flag = BTRFS_BLOCK_GROUP_RAID6,
.mindev_error = BTRFS_ERROR_DEV_RAID6_MIN_NOT_MET,
},
};
const char *btrfs_bg_type_to_raid_name(u64 flags)
{
const int index = btrfs_bg_flags_to_raid_index(flags);
if (index >= BTRFS_NR_RAID_TYPES)
return NULL;
return btrfs_raid_array[index].raid_name;
}
/*
* Fill @buf with textual description of @bg_flags, no more than @size_buf
* bytes including terminating null byte.
*/
void btrfs_describe_block_groups(u64 bg_flags, char *buf, u32 size_buf)
{
int i;
int ret;
char *bp = buf;
u64 flags = bg_flags;
u32 size_bp = size_buf;
if (!flags) {
strcpy(bp, "NONE");
return;
}
#define DESCRIBE_FLAG(flag, desc) \
do { \
if (flags & (flag)) { \
ret = snprintf(bp, size_bp, "%s|", (desc)); \
if (ret < 0 || ret >= size_bp) \
goto out_overflow; \
size_bp -= ret; \
bp += ret; \
flags &= ~(flag); \
} \
} while (0)
DESCRIBE_FLAG(BTRFS_BLOCK_GROUP_DATA, "data");
DESCRIBE_FLAG(BTRFS_BLOCK_GROUP_SYSTEM, "system");
DESCRIBE_FLAG(BTRFS_BLOCK_GROUP_METADATA, "metadata");
DESCRIBE_FLAG(BTRFS_AVAIL_ALLOC_BIT_SINGLE, "single");
for (i = 0; i < BTRFS_NR_RAID_TYPES; i++)
DESCRIBE_FLAG(btrfs_raid_array[i].bg_flag,
btrfs_raid_array[i].raid_name);
#undef DESCRIBE_FLAG
if (flags) {
ret = snprintf(bp, size_bp, "0x%llx|", flags);
size_bp -= ret;
}
if (size_bp < size_buf)
buf[size_buf - size_bp - 1] = '\0'; /* remove last | */
/*
* The text is trimmed, it's up to the caller to provide sufficiently
* large buffer
*/
out_overflow:;
}
static int init_first_rw_device(struct btrfs_trans_handle *trans);
static int btrfs_relocate_sys_chunks(struct btrfs_fs_info *fs_info);
static void btrfs_dev_stat_print_on_error(struct btrfs_device *dev);
static void btrfs_dev_stat_print_on_load(struct btrfs_device *device);
static int __btrfs_map_block(struct btrfs_fs_info *fs_info,
enum btrfs_map_op op,
u64 logical, u64 *length,
struct btrfs_bio **bbio_ret,
int mirror_num, int need_raid_map);
/*
* Device locking
* ==============
*
* There are several mutexes that protect manipulation of devices and low-level
* structures like chunks but not block groups, extents or files
*
* uuid_mutex (global lock)
* ------------------------
* protects the fs_uuids list that tracks all per-fs fs_devices, resulting from
* the SCAN_DEV ioctl registration or from mount either implicitly (the first
* device) or requested by the device= mount option
*
* the mutex can be very coarse and can cover long-running operations
*
* protects: updates to fs_devices counters like missing devices, rw devices,
* seeding, structure cloning, opening/closing devices at mount/umount time
*
* global::fs_devs - add, remove, updates to the global list
*
* does not protect: manipulation of the fs_devices::devices list!
*
* btrfs_device::name - renames (write side), read is RCU
*
* fs_devices::device_list_mutex (per-fs, with RCU)
* ------------------------------------------------
* protects updates to fs_devices::devices, ie. adding and deleting
*
* simple list traversal with read-only actions can be done with RCU protection
*
* may be used to exclude some operations from running concurrently without any
* modifications to the list (see write_all_supers)
*
* balance_mutex
* -------------
* protects balance structures (status, state) and context accessed from
* several places (internally, ioctl)
*
* chunk_mutex
* -----------
* protects chunks, adding or removing during allocation, trim or when a new
* device is added/removed. Additionally it also protects post_commit_list of
* individual devices, since they can be added to the transaction's
* post_commit_list only with chunk_mutex held.
*
* cleaner_mutex
* -------------
* a big lock that is held by the cleaner thread and prevents running subvolume
* cleaning together with relocation or delayed iputs
*
*
* Lock nesting
* ============
*
* uuid_mutex
* volume_mutex
* device_list_mutex
* chunk_mutex
* balance_mutex
*
*
* Exclusive operations, BTRFS_FS_EXCL_OP
* ======================================
*
* Maintains the exclusivity of the following operations that apply to the
* whole filesystem and cannot run in parallel.
*
* - Balance (*)
* - Device add
* - Device remove
* - Device replace (*)
* - Resize
*
* The device operations (as above) can be in one of the following states:
*
* - Running state
* - Paused state
* - Completed state
*
* Only device operations marked with (*) can go into the Paused state for the
* following reasons:
*
* - ioctl (only Balance can be Paused through ioctl)
* - filesystem remounted as read-only
* - filesystem unmounted and mounted as read-only
* - system power-cycle and filesystem mounted as read-only
* - filesystem or device errors leading to forced read-only
*
* BTRFS_FS_EXCL_OP flag is set and cleared using atomic operations.
* During the course of Paused state, the BTRFS_FS_EXCL_OP remains set.
* A device operation in Paused or Running state can be canceled or resumed
* either by ioctl (Balance only) or when remounted as read-write.
* BTRFS_FS_EXCL_OP flag is cleared when the device operation is canceled or
* completed.
*/
DEFINE_MUTEX(uuid_mutex);
static LIST_HEAD(fs_uuids);
struct list_head * __attribute_const__ btrfs_get_fs_uuids(void)
{
return &fs_uuids;
}
/*
* alloc_fs_devices - allocate struct btrfs_fs_devices
* @fsid: if not NULL, copy the UUID to fs_devices::fsid
* @metadata_fsid: if not NULL, copy the UUID to fs_devices::metadata_fsid
*
* Return a pointer to a new struct btrfs_fs_devices on success, or ERR_PTR().
* The returned struct is not linked onto any lists and can be destroyed with
* kfree() right away.
*/
static struct btrfs_fs_devices *alloc_fs_devices(const u8 *fsid,
const u8 *metadata_fsid)
{
struct btrfs_fs_devices *fs_devs;
fs_devs = kzalloc(sizeof(*fs_devs), GFP_KERNEL);
if (!fs_devs)
return ERR_PTR(-ENOMEM);
mutex_init(&fs_devs->device_list_mutex);
INIT_LIST_HEAD(&fs_devs->devices);
INIT_LIST_HEAD(&fs_devs->alloc_list);
INIT_LIST_HEAD(&fs_devs->fs_list);
if (fsid)
memcpy(fs_devs->fsid, fsid, BTRFS_FSID_SIZE);
if (metadata_fsid)
memcpy(fs_devs->metadata_uuid, metadata_fsid, BTRFS_FSID_SIZE);
else if (fsid)
memcpy(fs_devs->metadata_uuid, fsid, BTRFS_FSID_SIZE);
return fs_devs;
}
void btrfs_free_device(struct btrfs_device *device)
{
WARN_ON(!list_empty(&device->post_commit_list));
rcu_string_free(device->name);
extent_io_tree_release(&device->alloc_state);
bio_put(device->flush_bio);
kfree(device);
}
static void free_fs_devices(struct btrfs_fs_devices *fs_devices)
{
struct btrfs_device *device;
WARN_ON(fs_devices->opened);
while (!list_empty(&fs_devices->devices)) {
device = list_entry(fs_devices->devices.next,
struct btrfs_device, dev_list);
list_del(&device->dev_list);
btrfs_free_device(device);
}
kfree(fs_devices);
}
void __exit btrfs_cleanup_fs_uuids(void)
{
struct btrfs_fs_devices *fs_devices;
while (!list_empty(&fs_uuids)) {
fs_devices = list_entry(fs_uuids.next,
struct btrfs_fs_devices, fs_list);
list_del(&fs_devices->fs_list);
free_fs_devices(fs_devices);
}
}
/*
* Returns a pointer to a new btrfs_device on success; ERR_PTR() on error.
* Returned struct is not linked onto any lists and must be destroyed using
* btrfs_free_device.
*/
static struct btrfs_device *__alloc_device(void)
{
struct btrfs_device *dev;
dev = kzalloc(sizeof(*dev), GFP_KERNEL);
if (!dev)
return ERR_PTR(-ENOMEM);
/*
* Preallocate a bio that's always going to be used for flushing device
* barriers and matches the device lifespan
*/
dev->flush_bio = bio_alloc_bioset(GFP_KERNEL, 0, NULL);
if (!dev->flush_bio) {
kfree(dev);
return ERR_PTR(-ENOMEM);
}
INIT_LIST_HEAD(&dev->dev_list);
INIT_LIST_HEAD(&dev->dev_alloc_list);
INIT_LIST_HEAD(&dev->post_commit_list);
atomic_set(&dev->reada_in_flight, 0);
atomic_set(&dev->dev_stats_ccnt, 0);
btrfs_device_data_ordered_init(dev);
INIT_RADIX_TREE(&dev->reada_zones, GFP_NOFS & ~__GFP_DIRECT_RECLAIM);
INIT_RADIX_TREE(&dev->reada_extents, GFP_NOFS & ~__GFP_DIRECT_RECLAIM);
extent_io_tree_init(NULL, &dev->alloc_state, 0, NULL);
return dev;
}
static noinline struct btrfs_fs_devices *find_fsid(
const u8 *fsid, const u8 *metadata_fsid)
{
struct btrfs_fs_devices *fs_devices;
ASSERT(fsid);
/* Handle non-split brain cases */
list_for_each_entry(fs_devices, &fs_uuids, fs_list) {
if (metadata_fsid) {
if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0
&& memcmp(metadata_fsid, fs_devices->metadata_uuid,
BTRFS_FSID_SIZE) == 0)
return fs_devices;
} else {
if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
return fs_devices;
}
}
return NULL;
}
static struct btrfs_fs_devices *find_fsid_with_metadata_uuid(
struct btrfs_super_block *disk_super)
{
struct btrfs_fs_devices *fs_devices;
/*
* Handle scanned device having completed its fsid change but
* belonging to a fs_devices that was created by first scanning
* a device which didn't have its fsid/metadata_uuid changed
* at all and the CHANGING_FSID_V2 flag set.
*/
list_for_each_entry(fs_devices, &fs_uuids, fs_list) {
if (fs_devices->fsid_change &&
memcmp(disk_super->metadata_uuid, fs_devices->fsid,
BTRFS_FSID_SIZE) == 0 &&
memcmp(fs_devices->fsid, fs_devices->metadata_uuid,
BTRFS_FSID_SIZE) == 0) {
return fs_devices;
}
}
/*
* Handle scanned device having completed its fsid change but
* belonging to a fs_devices that was created by a device that
* has an outdated pair of fsid/metadata_uuid and
* CHANGING_FSID_V2 flag set.
*/
list_for_each_entry(fs_devices, &fs_uuids, fs_list) {
if (fs_devices->fsid_change &&
memcmp(fs_devices->metadata_uuid,
fs_devices->fsid, BTRFS_FSID_SIZE) != 0 &&
memcmp(disk_super->metadata_uuid, fs_devices->metadata_uuid,
BTRFS_FSID_SIZE) == 0) {
return fs_devices;
}
}
return find_fsid(disk_super->fsid, disk_super->metadata_uuid);
}
static int
btrfs_get_bdev_and_sb(const char *device_path, fmode_t flags, void *holder,
int flush, struct block_device **bdev,
struct btrfs_super_block **disk_super)
{
int ret;
*bdev = blkdev_get_by_path(device_path, flags, holder);
if (IS_ERR(*bdev)) {
ret = PTR_ERR(*bdev);
goto error;
}
if (flush)
filemap_write_and_wait((*bdev)->bd_inode->i_mapping);
ret = set_blocksize(*bdev, BTRFS_BDEV_BLOCKSIZE);
if (ret) {
blkdev_put(*bdev, flags);
goto error;
}
invalidate_bdev(*bdev);
*disk_super = btrfs_read_dev_super(*bdev);
if (IS_ERR(*disk_super)) {
ret = PTR_ERR(*disk_super);
blkdev_put(*bdev, flags);
goto error;
}
return 0;
error:
*bdev = NULL;
return ret;
}
static bool device_path_matched(const char *path, struct btrfs_device *device)
{
int found;
rcu_read_lock();
found = strcmp(rcu_str_deref(device->name), path);
rcu_read_unlock();
return found == 0;
}
/*
* Search and remove all stale (devices which are not mounted) devices.
* When both inputs are NULL, it will search and release all stale devices.
* path: Optional. When provided will it release all unmounted devices
* matching this path only.
* skip_dev: Optional. Will skip this device when searching for the stale
* devices.
* Return: 0 for success or if @path is NULL.
* -EBUSY if @path is a mounted device.
* -ENOENT if @path does not match any device in the list.
*/
static int btrfs_free_stale_devices(const char *path,
struct btrfs_device *skip_device)
{
struct btrfs_fs_devices *fs_devices, *tmp_fs_devices;
struct btrfs_device *device, *tmp_device;
int ret = 0;
if (path)
ret = -ENOENT;
list_for_each_entry_safe(fs_devices, tmp_fs_devices, &fs_uuids, fs_list) {
mutex_lock(&fs_devices->device_list_mutex);
list_for_each_entry_safe(device, tmp_device,
&fs_devices->devices, dev_list) {
if (skip_device && skip_device == device)
continue;
if (path && !device->name)
continue;
if (path && !device_path_matched(path, device))
continue;
if (fs_devices->opened) {
/* for an already deleted device return 0 */
if (path && ret != 0)
ret = -EBUSY;
break;
}
/* delete the stale device */
fs_devices->num_devices--;
list_del(&device->dev_list);
btrfs_free_device(device);
ret = 0;
if (fs_devices->num_devices == 0)
break;
}
mutex_unlock(&fs_devices->device_list_mutex);
if (fs_devices->num_devices == 0) {
btrfs_sysfs_remove_fsid(fs_devices);
list_del(&fs_devices->fs_list);
free_fs_devices(fs_devices);
}
}
return ret;
}
static int btrfs_open_one_device(struct btrfs_fs_devices *fs_devices,
struct btrfs_device *device, fmode_t flags,
void *holder)
{
struct request_queue *q;
struct block_device *bdev;
struct btrfs_super_block *disk_super;
u64 devid;
int ret;
if (device->bdev)
return -EINVAL;
if (!device->name)
return -EINVAL;
ret = btrfs_get_bdev_and_sb(device->name->str, flags, holder, 1,
&bdev, &disk_super);
if (ret)
return ret;
devid = btrfs_stack_device_id(&disk_super->dev_item);
if (devid != device->devid)
goto error_free_page;
if (memcmp(device->uuid, disk_super->dev_item.uuid, BTRFS_UUID_SIZE))
goto error_free_page;
device->generation = btrfs_super_generation(disk_super);
if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_SEEDING) {
if (btrfs_super_incompat_flags(disk_super) &
BTRFS_FEATURE_INCOMPAT_METADATA_UUID) {
pr_err(
"BTRFS: Invalid seeding and uuid-changed device detected\n");
goto error_free_page;
}
clear_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
fs_devices->seeding = true;
} else {
if (bdev_read_only(bdev))
clear_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
else
set_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
}
q = bdev_get_queue(bdev);
if (!blk_queue_nonrot(q))
fs_devices->rotating = true;
device->bdev = bdev;
clear_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
device->mode = flags;
fs_devices->open_devices++;
if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state) &&
device->devid != BTRFS_DEV_REPLACE_DEVID) {
fs_devices->rw_devices++;
list_add_tail(&device->dev_alloc_list, &fs_devices->alloc_list);
}
btrfs_release_disk_super(disk_super);
return 0;
error_free_page:
btrfs_release_disk_super(disk_super);
blkdev_put(bdev, flags);
return -EINVAL;
}
/*
* Handle scanned device having its CHANGING_FSID_V2 flag set and the fs_devices
* being created with a disk that has already completed its fsid change. Such
* disk can belong to an fs which has its FSID changed or to one which doesn't.
* Handle both cases here.
*/
static struct btrfs_fs_devices *find_fsid_inprogress(
struct btrfs_super_block *disk_super)
{
struct btrfs_fs_devices *fs_devices;
list_for_each_entry(fs_devices, &fs_uuids, fs_list) {
if (memcmp(fs_devices->metadata_uuid, fs_devices->fsid,
BTRFS_FSID_SIZE) != 0 &&
memcmp(fs_devices->metadata_uuid, disk_super->fsid,
BTRFS_FSID_SIZE) == 0 && !fs_devices->fsid_change) {
return fs_devices;
}
}
return find_fsid(disk_super->fsid, NULL);
}
static struct btrfs_fs_devices *find_fsid_changed(
struct btrfs_super_block *disk_super)
{
struct btrfs_fs_devices *fs_devices;
/*
* Handles the case where scanned device is part of an fs that had
* multiple successful changes of FSID but curently device didn't
* observe it. Meaning our fsid will be different than theirs. We need
* to handle two subcases :
* 1 - The fs still continues to have different METADATA/FSID uuids.
* 2 - The fs is switched back to its original FSID (METADATA/FSID
* are equal).
*/
list_for_each_entry(fs_devices, &fs_uuids, fs_list) {
/* Changed UUIDs */
if (memcmp(fs_devices->metadata_uuid, fs_devices->fsid,
BTRFS_FSID_SIZE) != 0 &&
memcmp(fs_devices->metadata_uuid, disk_super->metadata_uuid,
BTRFS_FSID_SIZE) == 0 &&
memcmp(fs_devices->fsid, disk_super->fsid,
BTRFS_FSID_SIZE) != 0)
return fs_devices;
/* Unchanged UUIDs */
if (memcmp(fs_devices->metadata_uuid, fs_devices->fsid,
BTRFS_FSID_SIZE) == 0 &&
memcmp(fs_devices->fsid, disk_super->metadata_uuid,
BTRFS_FSID_SIZE) == 0)
return fs_devices;
}
return NULL;
}
static struct btrfs_fs_devices *find_fsid_reverted_metadata(
struct btrfs_super_block *disk_super)
{
struct btrfs_fs_devices *fs_devices;
/*
* Handle the case where the scanned device is part of an fs whose last
* metadata UUID change reverted it to the original FSID. At the same
* time * fs_devices was first created by another constitutent device
* which didn't fully observe the operation. This results in an
* btrfs_fs_devices created with metadata/fsid different AND
* btrfs_fs_devices::fsid_change set AND the metadata_uuid of the
* fs_devices equal to the FSID of the disk.
*/
list_for_each_entry(fs_devices, &fs_uuids, fs_list) {
if (memcmp(fs_devices->fsid, fs_devices->metadata_uuid,
BTRFS_FSID_SIZE) != 0 &&
memcmp(fs_devices->metadata_uuid, disk_super->fsid,
BTRFS_FSID_SIZE) == 0 &&
fs_devices->fsid_change)
return fs_devices;
}
return NULL;
}
/*
* Add new device to list of registered devices
*
* Returns:
* device pointer which was just added or updated when successful
* error pointer when failed
*/
static noinline struct btrfs_device *device_list_add(const char *path,
struct btrfs_super_block *disk_super,
bool *new_device_added)
{
struct btrfs_device *device;
struct btrfs_fs_devices *fs_devices = NULL;
struct rcu_string *name;
u64 found_transid = btrfs_super_generation(disk_super);
u64 devid = btrfs_stack_device_id(&disk_super->dev_item);
bool has_metadata_uuid = (btrfs_super_incompat_flags(disk_super) &
BTRFS_FEATURE_INCOMPAT_METADATA_UUID);
bool fsid_change_in_progress = (btrfs_super_flags(disk_super) &
BTRFS_SUPER_FLAG_CHANGING_FSID_V2);
if (fsid_change_in_progress) {
if (!has_metadata_uuid)
fs_devices = find_fsid_inprogress(disk_super);
else
fs_devices = find_fsid_changed(disk_super);
} else if (has_metadata_uuid) {
fs_devices = find_fsid_with_metadata_uuid(disk_super);
} else {
fs_devices = find_fsid_reverted_metadata(disk_super);
if (!fs_devices)
fs_devices = find_fsid(disk_super->fsid, NULL);
}
if (!fs_devices) {
if (has_metadata_uuid)
fs_devices = alloc_fs_devices(disk_super->fsid,
disk_super->metadata_uuid);
else
fs_devices = alloc_fs_devices(disk_super->fsid, NULL);
if (IS_ERR(fs_devices))
return ERR_CAST(fs_devices);
fs_devices->fsid_change = fsid_change_in_progress;
mutex_lock(&fs_devices->device_list_mutex);
list_add(&fs_devices->fs_list, &fs_uuids);
device = NULL;
} else {
mutex_lock(&fs_devices->device_list_mutex);
device = btrfs_find_device(fs_devices, devid,
disk_super->dev_item.uuid, NULL, false);
/*
* If this disk has been pulled into an fs devices created by
* a device which had the CHANGING_FSID_V2 flag then replace the
* metadata_uuid/fsid values of the fs_devices.
*/
if (fs_devices->fsid_change &&
found_transid > fs_devices->latest_generation) {
memcpy(fs_devices->fsid, disk_super->fsid,
BTRFS_FSID_SIZE);
if (has_metadata_uuid)
memcpy(fs_devices->metadata_uuid,
disk_super->metadata_uuid,
BTRFS_FSID_SIZE);
else
memcpy(fs_devices->metadata_uuid,
disk_super->fsid, BTRFS_FSID_SIZE);
fs_devices->fsid_change = false;
}
}
if (!device) {
if (fs_devices->opened) {
mutex_unlock(&fs_devices->device_list_mutex);
return ERR_PTR(-EBUSY);
}
device = btrfs_alloc_device(NULL, &devid,
disk_super->dev_item.uuid);
if (IS_ERR(device)) {
mutex_unlock(&fs_devices->device_list_mutex);
/* we can safely leave the fs_devices entry around */
return device;
}
name = rcu_string_strdup(path, GFP_NOFS);
if (!name) {
btrfs_free_device(device);
mutex_unlock(&fs_devices->device_list_mutex);
return ERR_PTR(-ENOMEM);
}
rcu_assign_pointer(device->name, name);
list_add_rcu(&device->dev_list, &fs_devices->devices);
fs_devices->num_devices++;
device->fs_devices = fs_devices;
*new_device_added = true;
if (disk_super->label[0])
pr_info(
"BTRFS: device label %s devid %llu transid %llu %s scanned by %s (%d)\n",
disk_super->label, devid, found_transid, path,
current->comm, task_pid_nr(current));
else
pr_info(
"BTRFS: device fsid %pU devid %llu transid %llu %s scanned by %s (%d)\n",
disk_super->fsid, devid, found_transid, path,
current->comm, task_pid_nr(current));
} else if (!device->name || strcmp(device->name->str, path)) {
/*
* When FS is already mounted.
* 1. If you are here and if the device->name is NULL that
* means this device was missing at time of FS mount.
* 2. If you are here and if the device->name is different
* from 'path' that means either
* a. The same device disappeared and reappeared with
* different name. or
* b. The missing-disk-which-was-replaced, has
* reappeared now.
*
* We must allow 1 and 2a above. But 2b would be a spurious
* and unintentional.
*
* Further in case of 1 and 2a above, the disk at 'path'
* would have missed some transaction when it was away and
* in case of 2a the stale bdev has to be updated as well.
* 2b must not be allowed at all time.
*/
/*
* For now, we do allow update to btrfs_fs_device through the
* btrfs dev scan cli after FS has been mounted. We're still
* tracking a problem where systems fail mount by subvolume id
* when we reject replacement on a mounted FS.
*/
if (!fs_devices->opened && found_transid < device->generation) {
/*
* That is if the FS is _not_ mounted and if you
* are here, that means there is more than one
* disk with same uuid and devid.We keep the one
* with larger generation number or the last-in if
* generation are equal.
*/
mutex_unlock(&fs_devices->device_list_mutex);
return ERR_PTR(-EEXIST);
}
/*
* We are going to replace the device path for a given devid,
* make sure it's the same device if the device is mounted
*/
if (device->bdev) {
struct block_device *path_bdev;
path_bdev = lookup_bdev(path);
if (IS_ERR(path_bdev)) {
mutex_unlock(&fs_devices->device_list_mutex);
return ERR_CAST(path_bdev);
}
if (device->bdev != path_bdev) {
bdput(path_bdev);
mutex_unlock(&fs_devices->device_list_mutex);
btrfs_warn_in_rcu(device->fs_info,
"duplicate device fsid:devid for %pU:%llu old:%s new:%s",
disk_super->fsid, devid,
rcu_str_deref(device->name), path);
return ERR_PTR(-EEXIST);
}
bdput(path_bdev);
btrfs_info_in_rcu(device->fs_info,
"device fsid %pU devid %llu moved old:%s new:%s",
disk_super->fsid, devid,
rcu_str_deref(device->name), path);
}
name = rcu_string_strdup(path, GFP_NOFS);
if (!name) {
mutex_unlock(&fs_devices->device_list_mutex);
return ERR_PTR(-ENOMEM);
}
rcu_string_free(device->name);
rcu_assign_pointer(device->name, name);
if (test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state)) {
fs_devices->missing_devices--;
clear_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state);
}
}
/*
* Unmount does not free the btrfs_device struct but would zero
* generation along with most of the other members. So just update
* it back. We need it to pick the disk with largest generation
* (as above).
*/
if (!fs_devices->opened) {
device->generation = found_transid;
fs_devices->latest_generation = max_t(u64, found_transid,
fs_devices->latest_generation);
}
fs_devices->total_devices = btrfs_super_num_devices(disk_super);
mutex_unlock(&fs_devices->device_list_mutex);
return device;
}
static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
{
struct btrfs_fs_devices *fs_devices;
struct btrfs_device *device;
struct btrfs_device *orig_dev;
int ret = 0;
fs_devices = alloc_fs_devices(orig->fsid, NULL);
if (IS_ERR(fs_devices))
return fs_devices;
mutex_lock(&orig->device_list_mutex);
fs_devices->total_devices = orig->total_devices;
list_for_each_entry(orig_dev, &orig->devices, dev_list) {
struct rcu_string *name;
device = btrfs_alloc_device(NULL, &orig_dev->devid,
orig_dev->uuid);
if (IS_ERR(device)) {
ret = PTR_ERR(device);
goto error;
}
/*
* This is ok to do without rcu read locked because we hold the
* uuid mutex so nothing we touch in here is going to disappear.
*/
if (orig_dev->name) {
name = rcu_string_strdup(orig_dev->name->str,
GFP_KERNEL);
if (!name) {
btrfs_free_device(device);
ret = -ENOMEM;
goto error;
}
rcu_assign_pointer(device->name, name);
}
list_add(&device->dev_list, &fs_devices->devices);
device->fs_devices = fs_devices;
fs_devices->num_devices++;
}
mutex_unlock(&orig->device_list_mutex);
return fs_devices;
error:
mutex_unlock(&orig->device_list_mutex);
free_fs_devices(fs_devices);
return ERR_PTR(ret);
}
/*
* After we have read the system tree and know devids belonging to
* this filesystem, remove the device which does not belong there.
*/
void btrfs_free_extra_devids(struct btrfs_fs_devices *fs_devices, int step)
{
struct btrfs_device *device, *next;
struct btrfs_device *latest_dev = NULL;
mutex_lock(&uuid_mutex);
again:
/* This is the initialized path, it is safe to release the devices. */
list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
if (test_bit(BTRFS_DEV_STATE_IN_FS_METADATA,
&device->dev_state)) {
if (!test_bit(BTRFS_DEV_STATE_REPLACE_TGT,
&device->dev_state) &&
(!latest_dev ||
device->generation > latest_dev->generation)) {
latest_dev = device;
}
continue;
}
if (device->devid == BTRFS_DEV_REPLACE_DEVID) {
/*
* In the first step, keep the device which has
* the correct fsid and the devid that is used
* for the dev_replace procedure.
* In the second step, the dev_replace state is
* read from the device tree and it is known
* whether the procedure is really active or
* not, which means whether this device is
* used or whether it should be removed.
*/
if (step == 0 || test_bit(BTRFS_DEV_STATE_REPLACE_TGT,
&device->dev_state)) {
continue;
}
}
if (device->bdev) {
blkdev_put(device->bdev, device->mode);
device->bdev = NULL;
fs_devices->open_devices--;
}
if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) {
list_del_init(&device->dev_alloc_list);
clear_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
if (!test_bit(BTRFS_DEV_STATE_REPLACE_TGT,
&device->dev_state))
fs_devices->rw_devices--;
}
list_del_init(&device->dev_list);
fs_devices->num_devices--;
btrfs_free_device(device);
}
if (fs_devices->seed) {
fs_devices = fs_devices->seed;
goto again;
}
fs_devices->latest_bdev = latest_dev->bdev;
mutex_unlock(&uuid_mutex);
}
static void btrfs_close_bdev(struct btrfs_device *device)
{
if (!device->bdev)
return;
if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) {
sync_blockdev(device->bdev);
invalidate_bdev(device->bdev);
}
blkdev_put(device->bdev, device->mode);
}
static void btrfs_close_one_device(struct btrfs_device *device)
{
struct btrfs_fs_devices *fs_devices = device->fs_devices;
if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state) &&
device->devid != BTRFS_DEV_REPLACE_DEVID) {
list_del_init(&device->dev_alloc_list);
fs_devices->rw_devices--;
}
if (test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state))
fs_devices->missing_devices--;
btrfs_close_bdev(device);
if (device->bdev) {
fs_devices->open_devices--;
device->bdev = NULL;
}
clear_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
device->fs_info = NULL;
atomic_set(&device->dev_stats_ccnt, 0);
extent_io_tree_release(&device->alloc_state);
/* Verify the device is back in a pristine state */
ASSERT(!test_bit(BTRFS_DEV_STATE_FLUSH_SENT, &device->dev_state));
ASSERT(!test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state));
ASSERT(list_empty(&device->dev_alloc_list));
ASSERT(list_empty(&device->post_commit_list));
ASSERT(atomic_read(&device->reada_in_flight) == 0);
}
static int close_fs_devices(struct btrfs_fs_devices *fs_devices)
{
struct btrfs_device *device, *tmp;
if (--fs_devices->opened > 0)
return 0;
mutex_lock(&fs_devices->device_list_mutex);
list_for_each_entry_safe(device, tmp, &fs_devices->devices, dev_list) {
btrfs_close_one_device(device);
}
mutex_unlock(&fs_devices->device_list_mutex);
WARN_ON(fs_devices->open_devices);
WARN_ON(fs_devices->rw_devices);
fs_devices->opened = 0;
fs_devices->seeding = false;
return 0;
}
int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
{
struct btrfs_fs_devices *seed_devices = NULL;
int ret;
mutex_lock(&uuid_mutex);
ret = close_fs_devices(fs_devices);
if (!fs_devices->opened) {
seed_devices = fs_devices->seed;
fs_devices->seed = NULL;
}
mutex_unlock(&uuid_mutex);
while (seed_devices) {
fs_devices = seed_devices;
seed_devices = fs_devices->seed;
close_fs_devices(fs_devices);
free_fs_devices(fs_devices);
}
return ret;
}
static int open_fs_devices(struct btrfs_fs_devices *fs_devices,
fmode_t flags, void *holder)
{
struct btrfs_device *device;
struct btrfs_device *latest_dev = NULL;
int ret = 0;
flags |= FMODE_EXCL;
list_for_each_entry(device, &fs_devices->devices, dev_list) {
/* Just open everything we can; ignore failures here */
if (btrfs_open_one_device(fs_devices, device, flags, holder))
continue;
if (!latest_dev ||
device->generation > latest_dev->generation)
latest_dev = device;
}
if (fs_devices->open_devices == 0) {
ret = -EINVAL;
goto out;
}
fs_devices->opened = 1;
fs_devices->latest_bdev = latest_dev->bdev;
fs_devices->total_rw_bytes = 0;
fs_devices->chunk_alloc_policy = BTRFS_CHUNK_ALLOC_REGULAR;
out:
return ret;
}
static int devid_cmp(void *priv, struct list_head *a, struct list_head *b)
{
struct btrfs_device *dev1, *dev2;
dev1 = list_entry(a, struct btrfs_device, dev_list);
dev2 = list_entry(b, struct btrfs_device, dev_list);
if (dev1->devid < dev2->devid)
return -1;
else if (dev1->devid > dev2->devid)
return 1;
return 0;
}
int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
fmode_t flags, void *holder)
{
int ret;
lockdep_assert_held(&uuid_mutex);
mutex_lock(&fs_devices->device_list_mutex);
if (fs_devices->opened) {
fs_devices->opened++;
ret = 0;
} else {
list_sort(NULL, &fs_devices->devices, devid_cmp);
ret = open_fs_devices(fs_devices, flags, holder);
}
mutex_unlock(&fs_devices->device_list_mutex);
return ret;
}
void btrfs_release_disk_super(struct btrfs_super_block *super)
{
struct page *page = virt_to_page(super);
put_page(page);
}
static int btrfs_read_disk_super(struct block_device *bdev, u64 bytenr,
struct page **page,
struct btrfs_super_block **disk_super)
{
void *p;
pgoff_t index;
/* make sure our super fits in the device */
if (bytenr + PAGE_SIZE >= i_size_read(bdev->bd_inode))
return 1;
/* make sure our super fits in the page */
if (sizeof(**disk_super) > PAGE_SIZE)
return 1;
/* make sure our super doesn't straddle pages on disk */
index = bytenr >> PAGE_SHIFT;
if ((bytenr + sizeof(**disk_super) - 1) >> PAGE_SHIFT != index)
return 1;
/* pull in the page with our super */
*page = read_cache_page_gfp(bdev->bd_inode->i_mapping,
index, GFP_KERNEL);
if (IS_ERR(*page))
return 1;
p = page_address(*page);
/* align our pointer to the offset of the super block */
*disk_super = p + offset_in_page(bytenr);
if (btrfs_super_bytenr(*disk_super) != bytenr ||
btrfs_super_magic(*disk_super) != BTRFS_MAGIC) {
btrfs_release_disk_super(p);
return 1;
}
if ((*disk_super)->label[0] &&
(*disk_super)->label[BTRFS_LABEL_SIZE - 1])
(*disk_super)->label[BTRFS_LABEL_SIZE - 1] = '\0';
return 0;
}
int btrfs_forget_devices(const char *path)
{
int ret;
mutex_lock(&uuid_mutex);
ret = btrfs_free_stale_devices(strlen(path) ? path : NULL, NULL);
mutex_unlock(&uuid_mutex);
return ret;
}
/*
* Look for a btrfs signature on a device. This may be called out of the mount path
* and we are not allowed to call set_blocksize during the scan. The superblock
* is read via pagecache
*/
struct btrfs_device *btrfs_scan_one_device(const char *path, fmode_t flags,
void *holder)
{
struct btrfs_super_block *disk_super;
bool new_device_added = false;
struct btrfs_device *device = NULL;
struct block_device *bdev;
struct page *page;
u64 bytenr;
lockdep_assert_held(&uuid_mutex);
/*
* we would like to check all the supers, but that would make
* a btrfs mount succeed after a mkfs from a different FS.
* So, we need to add a special mount option to scan for
* later supers, using BTRFS_SUPER_MIRROR_MAX instead
*/
bytenr = btrfs_sb_offset(0);
flags |= FMODE_EXCL;
bdev = blkdev_get_by_path(path, flags, holder);
if (IS_ERR(bdev))
return ERR_CAST(bdev);
if (btrfs_read_disk_super(bdev, bytenr, &page, &disk_super)) {
device = ERR_PTR(-EINVAL);
goto error_bdev_put;
}
device = device_list_add(path, disk_super, &new_device_added);
if (!IS_ERR(device)) {
if (new_device_added)
btrfs_free_stale_devices(path, device);
}
btrfs_release_disk_super(disk_super);
error_bdev_put:
blkdev_put(bdev, flags);
return device;
}
/*
* Try to find a chunk that intersects [start, start + len] range and when one
* such is found, record the end of it in *start
*/
static bool contains_pending_extent(struct btrfs_device *device, u64 *start,
u64 len)
{
u64 physical_start, physical_end;
lockdep_assert_held(&device->fs_info->chunk_mutex);
if (!find_first_extent_bit(&device->alloc_state, *start,
&physical_start, &physical_end,
CHUNK_ALLOCATED, NULL)) {
if (in_range(physical_start, *start, len) ||
in_range(*start, physical_start,
physical_end - physical_start)) {
*start = physical_end + 1;
return true;
}
}
return false;
}
static u64 dev_extent_search_start(struct btrfs_device *device, u64 start)
{
switch (device->fs_devices->chunk_alloc_policy) {
case BTRFS_CHUNK_ALLOC_REGULAR:
/*
* We don't want to overwrite the superblock on the drive nor
* any area used by the boot loader (grub for example), so we
* make sure to start at an offset of at least 1MB.
*/
return max_t(u64, start, SZ_1M);
default:
BUG();
}
}
/**
* dev_extent_hole_check - check if specified hole is suitable for allocation
* @device: the device which we have the hole
* @hole_start: starting position of the hole
* @hole_size: the size of the hole
* @num_bytes: the size of the free space that we need
*
* This function may modify @hole_start and @hole_end to reflect the suitable
* position for allocation. Returns 1 if hole position is updated, 0 otherwise.
*/
static bool dev_extent_hole_check(struct btrfs_device *device, u64 *hole_start,
u64 *hole_size, u64 num_bytes)
{
bool changed = false;
u64 hole_end = *hole_start + *hole_size;
/*
* Check before we set max_hole_start, otherwise we could end up
* sending back this offset anyway.
*/
if (contains_pending_extent(device, hole_start, *hole_size)) {
if (hole_end >= *hole_start)
*hole_size = hole_end - *hole_start;
else
*hole_size = 0;
changed = true;
}
switch (device->fs_devices->chunk_alloc_policy) {
case BTRFS_CHUNK_ALLOC_REGULAR:
/* No extra check */
break;
default:
BUG();
}
return changed;
}
/*
* find_free_dev_extent_start - find free space in the specified device
* @device: the device which we search the free space in
* @num_bytes: the size of the free space that we need
* @search_start: the position from which to begin the search
* @start: store the start of the free space.
* @len: the size of the free space. that we find, or the size
* of the max free space if we don't find suitable free space
*
* this uses a pretty simple search, the expectation is that it is
* called very infrequently and that a given device has a small number
* of extents
*
* @start is used to store the start of the free space if we find. But if we
* don't find suitable free space, it will be used to store the start position
* of the max free space.
*
* @len is used to store the size of the free space that we find.
* But if we don't find suitable free space, it is used to store the size of
* the max free space.
*
* NOTE: This function will search *commit* root of device tree, and does extra
* check to ensure dev extents are not double allocated.
* This makes the function safe to allocate dev extents but may not report
* correct usable device space, as device extent freed in current transaction
* is not reported as avaiable.
*/
static int find_free_dev_extent_start(struct btrfs_device *device,
u64 num_bytes, u64 search_start, u64 *start,
u64 *len)
{
struct btrfs_fs_info *fs_info = device->fs_info;
struct btrfs_root *root = fs_info->dev_root;
struct btrfs_key key;
struct btrfs_dev_extent *dev_extent;
struct btrfs_path *path;
u64 hole_size;
u64 max_hole_start;
u64 max_hole_size;
u64 extent_end;
u64 search_end = device->total_bytes;
int ret;
int slot;
struct extent_buffer *l;
search_start = dev_extent_search_start(device, search_start);
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
max_hole_start = search_start;
max_hole_size = 0;
again:
if (search_start >= search_end ||
test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) {
ret = -ENOSPC;
goto out;
}
path->reada = READA_FORWARD;
path->search_commit_root = 1;
path->skip_locking = 1;
key.objectid = device->devid;
key.offset = search_start;
key.type = BTRFS_DEV_EXTENT_KEY;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto out;
if (ret > 0) {
ret = btrfs_previous_item(root, path, key.objectid, key.type);
if (ret < 0)
goto out;
}
while (1) {
l = path->nodes[0];
slot = path->slots[0];
if (slot >= btrfs_header_nritems(l)) {
ret = btrfs_next_leaf(root, path);
if (ret == 0)
continue;
if (ret < 0)
goto out;
break;
}
btrfs_item_key_to_cpu(l, &key, slot);
if (key.objectid < device->devid)
goto next;
if (key.objectid > device->devid)
break;
if (key.type != BTRFS_DEV_EXTENT_KEY)
goto next;
if (key.offset > search_start) {
hole_size = key.offset - search_start;
dev_extent_hole_check(device, &search_start, &hole_size,
num_bytes);
if (hole_size > max_hole_size) {
max_hole_start = search_start;
max_hole_size = hole_size;
}
/*
* If this free space is greater than which we need,
* it must be the max free space that we have found
* until now, so max_hole_start must point to the start
* of this free space and the length of this free space
* is stored in max_hole_size. Thus, we return
* max_hole_start and max_hole_size and go back to the
* caller.
*/
if (hole_size >= num_bytes) {
ret = 0;
goto out;
}
}
dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
extent_end = key.offset + btrfs_dev_extent_length(l,
dev_extent);
if (extent_end > search_start)
search_start = extent_end;
next:
path->slots[0]++;
cond_resched();
}
/*
* At this point, search_start should be the end of
* allocated dev extents, and when shrinking the device,
* search_end may be smaller than search_start.
*/
if (search_end > search_start) {
hole_size = search_end - search_start;
if (dev_extent_hole_check(device, &search_start, &hole_size,
num_bytes)) {
btrfs_release_path(path);
goto again;
}
if (hole_size > max_hole_size) {
max_hole_start = search_start;
max_hole_size = hole_size;
}
}
/* See above. */
if (max_hole_size < num_bytes)
ret = -ENOSPC;
else
ret = 0;
out:
btrfs_free_path(path);
*start = max_hole_start;
if (len)
*len = max_hole_size;
return ret;
}
int find_free_dev_extent(struct btrfs_device *device, u64 num_bytes,
u64 *start, u64 *len)
{
/* FIXME use last free of some kind */
return find_free_dev_extent_start(device, num_bytes, 0, start, len);
}
static int btrfs_free_dev_extent(struct btrfs_trans_handle *trans,
struct btrfs_device *device,
u64 start, u64 *dev_extent_len)
{
struct btrfs_fs_info *fs_info = device->fs_info;
struct btrfs_root *root = fs_info->dev_root;
int ret;
struct btrfs_path *path;
struct btrfs_key key;
struct btrfs_key found_key;
struct extent_buffer *leaf = NULL;
struct btrfs_dev_extent *extent = NULL;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
key.objectid = device->devid;
key.offset = start;
key.type = BTRFS_DEV_EXTENT_KEY;
again:
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret > 0) {
ret = btrfs_previous_item(root, path, key.objectid,
BTRFS_DEV_EXTENT_KEY);
if (ret)
goto out;
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
extent = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_dev_extent);
BUG_ON(found_key.offset > start || found_key.offset +
btrfs_dev_extent_length(leaf, extent) < start);
key = found_key;
btrfs_release_path(path);
goto again;
} else if (ret == 0) {
leaf = path->nodes[0];
extent = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_dev_extent);
} else {
btrfs_handle_fs_error(fs_info, ret, "Slot search failed");
goto out;
}
*dev_extent_len = btrfs_dev_extent_length(leaf, extent);
ret = btrfs_del_item(trans, root, path);
if (ret) {
btrfs_handle_fs_error(fs_info, ret,
"Failed to remove dev extent item");
} else {
set_bit(BTRFS_TRANS_HAVE_FREE_BGS, &trans->transaction->flags);
}
out:
btrfs_free_path(path);
return ret;
}
static int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
struct btrfs_device *device,
u64 chunk_offset, u64 start, u64 num_bytes)
{
int ret;
struct btrfs_path *path;
struct btrfs_fs_info *fs_info = device->fs_info;
struct btrfs_root *root = fs_info->dev_root;
struct btrfs_dev_extent *extent;
struct extent_buffer *leaf;
struct btrfs_key key;
WARN_ON(!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state));
WARN_ON(test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state));
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
key.objectid = device->devid;
key.offset = start;
key.type = BTRFS_DEV_EXTENT_KEY;
ret = btrfs_insert_empty_item(trans, root, path, &key,
sizeof(*extent));
if (ret)
goto out;
leaf = path->nodes[0];
extent = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_dev_extent);
btrfs_set_dev_extent_chunk_tree(leaf, extent,
BTRFS_CHUNK_TREE_OBJECTID);
btrfs_set_dev_extent_chunk_objectid(leaf, extent,
BTRFS_FIRST_CHUNK_TREE_OBJECTID);
btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);
btrfs_set_dev_extent_length(leaf, extent, num_bytes);
btrfs_mark_buffer_dirty(leaf);
out:
btrfs_free_path(path);
return ret;
}
static u64 find_next_chunk(struct btrfs_fs_info *fs_info)
{
struct extent_map_tree *em_tree;
struct extent_map *em;
struct rb_node *n;
u64 ret = 0;
em_tree = &fs_info->mapping_tree;
read_lock(&em_tree->lock);
n = rb_last(&em_tree->map.rb_root);
if (n) {
em = rb_entry(n, struct extent_map, rb_node);
ret = em->start + em->len;
}
read_unlock(&em_tree->lock);
return ret;
}
static noinline int find_next_devid(struct btrfs_fs_info *fs_info,
u64 *devid_ret)
{
int ret;
struct btrfs_key key;
struct btrfs_key found_key;
struct btrfs_path *path;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
key.type = BTRFS_DEV_ITEM_KEY;
key.offset = (u64)-1;
ret = btrfs_search_slot(NULL, fs_info->chunk_root, &key, path, 0, 0);
if (ret < 0)
goto error;
if (ret == 0) {
/* Corruption */
btrfs_err(fs_info, "corrupted chunk tree devid -1 matched");
ret = -EUCLEAN;
goto error;
}
ret = btrfs_previous_item(fs_info->chunk_root, path,
BTRFS_DEV_ITEMS_OBJECTID,
BTRFS_DEV_ITEM_KEY);
if (ret) {
*devid_ret = 1;
} else {
btrfs_item_key_to_cpu(path->nodes[0], &found_key,
path->slots[0]);
*devid_ret = found_key.offset + 1;
}
ret = 0;
error:
btrfs_free_path(path);
return ret;
}
/*
* the device information is stored in the chunk root
* the btrfs_device struct should be fully filled in
*/
static int btrfs_add_dev_item(struct btrfs_trans_handle *trans,
struct btrfs_device *device)
{
int ret;
struct btrfs_path *path;
struct btrfs_dev_item *dev_item;
struct extent_buffer *leaf;
struct btrfs_key key;
unsigned long ptr;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
key.type = BTRFS_DEV_ITEM_KEY;
key.offset = device->devid;
ret = btrfs_insert_empty_item(trans, trans->fs_info->chunk_root, path,
&key, sizeof(*dev_item));
if (ret)
goto out;
leaf = path->nodes[0];
dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
btrfs_set_device_id(leaf, dev_item, device->devid);
btrfs_set_device_generation(leaf, dev_item, 0);
btrfs_set_device_type(leaf, dev_item, device->type);
btrfs_set_device_io_align(leaf, dev_item, device->io_align);
btrfs_set_device_io_width(leaf, dev_item, device->io_width);
btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
btrfs_set_device_total_bytes(leaf, dev_item,
btrfs_device_get_disk_total_bytes(device));
btrfs_set_device_bytes_used(leaf, dev_item,
btrfs_device_get_bytes_used(device));
btrfs_set_device_group(leaf, dev_item, 0);
btrfs_set_device_seek_speed(leaf, dev_item, 0);
btrfs_set_device_bandwidth(leaf, dev_item, 0);
btrfs_set_device_start_offset(leaf, dev_item, 0);
ptr = btrfs_device_uuid(dev_item);
write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
ptr = btrfs_device_fsid(dev_item);
write_extent_buffer(leaf, trans->fs_info->fs_devices->metadata_uuid,
ptr, BTRFS_FSID_SIZE);
btrfs_mark_buffer_dirty(leaf);
ret = 0;
out:
btrfs_free_path(path);
return ret;
}
/*
* Function to update ctime/mtime for a given device path.
* Mainly used for ctime/mtime based probe like libblkid.
*/
static void update_dev_time(const char *path_name)
{
struct file *filp;
filp = filp_open(path_name, O_RDWR, 0);
if (IS_ERR(filp))
return;
file_update_time(filp);
filp_close(filp, NULL);
}
static int btrfs_rm_dev_item(struct btrfs_device *device)
{
struct btrfs_root *root = device->fs_info->chunk_root;
int ret;
struct btrfs_path *path;
struct btrfs_key key;
struct btrfs_trans_handle *trans;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
trans = btrfs_start_transaction(root, 0);
if (IS_ERR(trans)) {
btrfs_free_path(path);
return PTR_ERR(trans);
}
key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
key.type = BTRFS_DEV_ITEM_KEY;
key.offset = device->devid;
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret) {
if (ret > 0)
ret = -ENOENT;
btrfs_abort_transaction(trans, ret);
btrfs_end_transaction(trans);
goto out;
}
ret = btrfs_del_item(trans, root, path);
if (ret) {
btrfs_abort_transaction(trans, ret);
btrfs_end_transaction(trans);
}
out:
btrfs_free_path(path);
if (!ret)
ret = btrfs_commit_transaction(trans);
return ret;
}
/*
* Verify that @num_devices satisfies the RAID profile constraints in the whole
* filesystem. It's up to the caller to adjust that number regarding eg. device
* replace.
*/
static int btrfs_check_raid_min_devices(struct btrfs_fs_info *fs_info,
u64 num_devices)
{
u64 all_avail;
unsigned seq;
int i;
do {
seq = read_seqbegin(&fs_info->profiles_lock);
all_avail = fs_info->avail_data_alloc_bits |
fs_info->avail_system_alloc_bits |
fs_info->avail_metadata_alloc_bits;
} while (read_seqretry(&fs_info->profiles_lock, seq));
for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
if (!(all_avail & btrfs_raid_array[i].bg_flag))
continue;
if (num_devices < btrfs_raid_array[i].devs_min) {
int ret = btrfs_raid_array[i].mindev_error;
if (ret)
return ret;
}
}
return 0;
}
static struct btrfs_device * btrfs_find_next_active_device(
struct btrfs_fs_devices *fs_devs, struct btrfs_device *device)
{
struct btrfs_device *next_device;
list_for_each_entry(next_device, &fs_devs->devices, dev_list) {
if (next_device != device &&
!test_bit(BTRFS_DEV_STATE_MISSING, &next_device->dev_state)
&& next_device->bdev)
return next_device;
}
return NULL;
}
/*
* Helper function to check if the given device is part of s_bdev / latest_bdev
* and replace it with the provided or the next active device, in the context
* where this function called, there should be always be another device (or
* this_dev) which is active.
*/
void __cold btrfs_assign_next_active_device(struct btrfs_device *device,
struct btrfs_device *this_dev)
{
struct btrfs_fs_info *fs_info = device->fs_info;
struct btrfs_device *next_device;
if (this_dev)
next_device = this_dev;
else
next_device = btrfs_find_next_active_device(fs_info->fs_devices,
device);
ASSERT(next_device);
if (fs_info->sb->s_bdev &&
(fs_info->sb->s_bdev == device->bdev))
fs_info->sb->s_bdev = next_device->bdev;
if (fs_info->fs_devices->latest_bdev == device->bdev)
fs_info->fs_devices->latest_bdev = next_device->bdev;
}
/*
* Return btrfs_fs_devices::num_devices excluding the device that's being
* currently replaced.
*/
static u64 btrfs_num_devices(struct btrfs_fs_info *fs_info)
{
u64 num_devices = fs_info->fs_devices->num_devices;
down_read(&fs_info->dev_replace.rwsem);
if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace)) {
ASSERT(num_devices > 1);
num_devices--;
}
up_read(&fs_info->dev_replace.rwsem);
return num_devices;
}
static void btrfs_scratch_superblocks(struct btrfs_fs_info *fs_info,
struct block_device *bdev,
const char *device_path)
{
struct btrfs_super_block *disk_super;
int copy_num;
if (!bdev)
return;
for (copy_num = 0; copy_num < BTRFS_SUPER_MIRROR_MAX; copy_num++) {
struct page *page;
int ret;
disk_super = btrfs_read_dev_one_super(bdev, copy_num);
if (IS_ERR(disk_super))
continue;
memset(&disk_super->magic, 0, sizeof(disk_super->magic));
page = virt_to_page(disk_super);
set_page_dirty(page);
lock_page(page);
/* write_on_page() unlocks the page */
ret = write_one_page(page);
if (ret)
btrfs_warn(fs_info,
"error clearing superblock number %d (%d)",
copy_num, ret);
btrfs_release_disk_super(disk_super);
}
/* Notify udev that device has changed */
btrfs_kobject_uevent(bdev, KOBJ_CHANGE);
/* Update ctime/mtime for device path for libblkid */
update_dev_time(device_path);
}
int btrfs_rm_device(struct btrfs_fs_info *fs_info, const char *device_path,
u64 devid)
{
struct btrfs_device *device;
struct btrfs_fs_devices *cur_devices;
struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
u64 num_devices;
int ret = 0;
mutex_lock(&uuid_mutex);
num_devices = btrfs_num_devices(fs_info);
ret = btrfs_check_raid_min_devices(fs_info, num_devices - 1);
if (ret)
goto out;
device = btrfs_find_device_by_devspec(fs_info, devid, device_path);
if (IS_ERR(device)) {
if (PTR_ERR(device) == -ENOENT &&
strcmp(device_path, "missing") == 0)
ret = BTRFS_ERROR_DEV_MISSING_NOT_FOUND;
else
ret = PTR_ERR(device);
goto out;
}
if (btrfs_pinned_by_swapfile(fs_info, device)) {
btrfs_warn_in_rcu(fs_info,
"cannot remove device %s (devid %llu) due to active swapfile",
rcu_str_deref(device->name), device->devid);
ret = -ETXTBSY;
goto out;
}
if (test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) {
ret = BTRFS_ERROR_DEV_TGT_REPLACE;
goto out;
}
if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state) &&
fs_info->fs_devices->rw_devices == 1) {
ret = BTRFS_ERROR_DEV_ONLY_WRITABLE;
goto out;
}
if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) {
mutex_lock(&fs_info->chunk_mutex);
list_del_init(&device->dev_alloc_list);
device->fs_devices->rw_devices--;
mutex_unlock(&fs_info->chunk_mutex);
}
mutex_unlock(&uuid_mutex);
ret = btrfs_shrink_device(device, 0);
mutex_lock(&uuid_mutex);
if (ret)
goto error_undo;
/*
* TODO: the superblock still includes this device in its num_devices
* counter although write_all_supers() is not locked out. This
* could give a filesystem state which requires a degraded mount.
*/
ret = btrfs_rm_dev_item(device);
if (ret)
goto error_undo;
clear_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
btrfs_scrub_cancel_dev(device);
/*
* the device list mutex makes sure that we don't change
* the device list while someone else is writing out all
* the device supers. Whoever is writing all supers, should
* lock the device list mutex before getting the number of
* devices in the super block (super_copy). Conversely,
* whoever updates the number of devices in the super block
* (super_copy) should hold the device list mutex.
*/
/*
* In normal cases the cur_devices == fs_devices. But in case
* of deleting a seed device, the cur_devices should point to
* its own fs_devices listed under the fs_devices->seed.
*/
cur_devices = device->fs_devices;
mutex_lock(&fs_devices->device_list_mutex);
list_del_rcu(&device->dev_list);
cur_devices->num_devices--;
cur_devices->total_devices--;
/* Update total_devices of the parent fs_devices if it's seed */
if (cur_devices != fs_devices)
fs_devices->total_devices--;
if (test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state))
cur_devices->missing_devices--;
btrfs_assign_next_active_device(device, NULL);
if (device->bdev) {
cur_devices->open_devices--;
/* remove sysfs entry */
btrfs_sysfs_remove_devices_dir(fs_devices, device);
}
num_devices = btrfs_super_num_devices(fs_info->super_copy) - 1;
btrfs_set_super_num_devices(fs_info->super_copy, num_devices);
mutex_unlock(&fs_devices->device_list_mutex);
/*
* at this point, the device is zero sized and detached from
* the devices list. All that's left is to zero out the old
* supers and free the device.
*/
if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state))
btrfs_scratch_superblocks(fs_info, device->bdev,
device->name->str);
btrfs_close_bdev(device);
synchronize_rcu();
btrfs_free_device(device);
if (cur_devices->open_devices == 0) {
while (fs_devices) {
if (fs_devices->seed == cur_devices) {
fs_devices->seed = cur_devices->seed;
break;
}
fs_devices = fs_devices->seed;
}
cur_devices->seed = NULL;
close_fs_devices(cur_devices);
free_fs_devices(cur_devices);
}
out:
mutex_unlock(&uuid_mutex);
return ret;
error_undo:
if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) {
mutex_lock(&fs_info->chunk_mutex);
list_add(&device->dev_alloc_list,
&fs_devices->alloc_list);
device->fs_devices->rw_devices++;
mutex_unlock(&fs_info->chunk_mutex);
}
goto out;
}
void btrfs_rm_dev_replace_remove_srcdev(struct btrfs_device *srcdev)
{
struct btrfs_fs_devices *fs_devices;
lockdep_assert_held(&srcdev->fs_info->fs_devices->device_list_mutex);
/*
* in case of fs with no seed, srcdev->fs_devices will point
* to fs_devices of fs_info. However when the dev being replaced is
* a seed dev it will point to the seed's local fs_devices. In short
* srcdev will have its correct fs_devices in both the cases.
*/
fs_devices = srcdev->fs_devices;
list_del_rcu(&srcdev->dev_list);
list_del(&srcdev->dev_alloc_list);
fs_devices->num_devices--;
if (test_bit(BTRFS_DEV_STATE_MISSING, &srcdev->dev_state))
fs_devices->missing_devices--;
if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &srcdev->dev_state))
fs_devices->rw_devices--;
if (srcdev->bdev)
fs_devices->open_devices--;
}
void btrfs_rm_dev_replace_free_srcdev(struct btrfs_device *srcdev)
{
struct btrfs_fs_info *fs_info = srcdev->fs_info;
struct btrfs_fs_devices *fs_devices = srcdev->fs_devices;
if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &srcdev->dev_state)) {
/* zero out the old super if it is writable */
btrfs_scratch_superblocks(fs_info, srcdev->bdev,
srcdev->name->str);
}
btrfs_close_bdev(srcdev);
synchronize_rcu();
btrfs_free_device(srcdev);
/* if this is no devs we rather delete the fs_devices */
if (!fs_devices->num_devices) {
struct btrfs_fs_devices *tmp_fs_devices;
/*
* On a mounted FS, num_devices can't be zero unless it's a
* seed. In case of a seed device being replaced, the replace
* target added to the sprout FS, so there will be no more
* device left under the seed FS.
*/
ASSERT(fs_devices->seeding);
tmp_fs_devices = fs_info->fs_devices;
while (tmp_fs_devices) {
if (tmp_fs_devices->seed == fs_devices) {
tmp_fs_devices->seed = fs_devices->seed;
break;
}
tmp_fs_devices = tmp_fs_devices->seed;
}
fs_devices->seed = NULL;
close_fs_devices(fs_devices);
free_fs_devices(fs_devices);
}
}
void btrfs_destroy_dev_replace_tgtdev(struct btrfs_device *tgtdev)
{
struct btrfs_fs_devices *fs_devices = tgtdev->fs_info->fs_devices;
mutex_lock(&fs_devices->device_list_mutex);
btrfs_sysfs_remove_devices_dir(fs_devices, tgtdev);
if (tgtdev->bdev)
fs_devices->open_devices--;
fs_devices->num_devices--;
btrfs_assign_next_active_device(tgtdev, NULL);
list_del_rcu(&tgtdev->dev_list);
mutex_unlock(&fs_devices->device_list_mutex);
/*
* The update_dev_time() with in btrfs_scratch_superblocks()
* may lead to a call to btrfs_show_devname() which will try
* to hold device_list_mutex. And here this device
* is already out of device list, so we don't have to hold
* the device_list_mutex lock.
*/
btrfs_scratch_superblocks(tgtdev->fs_info, tgtdev->bdev,
tgtdev->name->str);
btrfs_close_bdev(tgtdev);
synchronize_rcu();
btrfs_free_device(tgtdev);
}
static struct btrfs_device *btrfs_find_device_by_path(
struct btrfs_fs_info *fs_info, const char *device_path)
{
int ret = 0;
struct btrfs_super_block *disk_super;
u64 devid;
u8 *dev_uuid;
struct block_device *bdev;
struct btrfs_device *device;
ret = btrfs_get_bdev_and_sb(device_path, FMODE_READ,
fs_info->bdev_holder, 0, &bdev, &disk_super);
if (ret)
return ERR_PTR(ret);
devid = btrfs_stack_device_id(&disk_super->dev_item);
dev_uuid = disk_super->dev_item.uuid;
if (btrfs_fs_incompat(fs_info, METADATA_UUID))
device = btrfs_find_device(fs_info->fs_devices, devid, dev_uuid,
disk_super->metadata_uuid, true);
else
device = btrfs_find_device(fs_info->fs_devices, devid, dev_uuid,
disk_super->fsid, true);
btrfs_release_disk_super(disk_super);
if (!device)
device = ERR_PTR(-ENOENT);
blkdev_put(bdev, FMODE_READ);
return device;
}
/*
* Lookup a device given by device id, or the path if the id is 0.
*/
struct btrfs_device *btrfs_find_device_by_devspec(
struct btrfs_fs_info *fs_info, u64 devid,
const char *device_path)
{
struct btrfs_device *device;
if (devid) {
device = btrfs_find_device(fs_info->fs_devices, devid, NULL,
NULL, true);
if (!device)
return ERR_PTR(-ENOENT);
return device;
}
if (!device_path || !device_path[0])
return ERR_PTR(-EINVAL);
if (strcmp(device_path, "missing") == 0) {
/* Find first missing device */
list_for_each_entry(device, &fs_info->fs_devices->devices,
dev_list) {
if (test_bit(BTRFS_DEV_STATE_IN_FS_METADATA,
&device->dev_state) && !device->bdev)
return device;
}
return ERR_PTR(-ENOENT);
}
return btrfs_find_device_by_path(fs_info, device_path);
}
/*
* does all the dirty work required for changing file system's UUID.
*/
static int btrfs_prepare_sprout(struct btrfs_fs_info *fs_info)
{
struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
struct btrfs_fs_devices *old_devices;
struct btrfs_fs_devices *seed_devices;
struct btrfs_super_block *disk_super = fs_info->super_copy;
struct btrfs_device *device;
u64 super_flags;
lockdep_assert_held(&uuid_mutex);
if (!fs_devices->seeding)
return -EINVAL;
seed_devices = alloc_fs_devices(NULL, NULL);
if (IS_ERR(seed_devices))
return PTR_ERR(seed_devices);
old_devices = clone_fs_devices(fs_devices);
if (IS_ERR(old_devices)) {
kfree(seed_devices);
return PTR_ERR(old_devices);
}
list_add(&old_devices->fs_list, &fs_uuids);
memcpy(seed_devices, fs_devices, sizeof(*seed_devices));
seed_devices->opened = 1;
INIT_LIST_HEAD(&seed_devices->devices);
INIT_LIST_HEAD(&seed_devices->alloc_list);
mutex_init(&seed_devices->device_list_mutex);
mutex_lock(&fs_devices->device_list_mutex);
list_splice_init_rcu(&fs_devices->devices, &seed_devices->devices,
synchronize_rcu);
list_for_each_entry(device, &seed_devices->devices, dev_list)
device->fs_devices = seed_devices;
mutex_lock(&fs_info->chunk_mutex);
list_splice_init(&fs_devices->alloc_list, &seed_devices->alloc_list);
mutex_unlock(&fs_info->chunk_mutex);
fs_devices->seeding = false;
fs_devices->num_devices = 0;
fs_devices->open_devices = 0;
fs_devices->missing_devices = 0;
fs_devices->rotating = false;
fs_devices->seed = seed_devices;
generate_random_uuid(fs_devices->fsid);
memcpy(fs_devices->metadata_uuid, fs_devices->fsid, BTRFS_FSID_SIZE);
memcpy(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
mutex_unlock(&fs_devices->device_list_mutex);
super_flags = btrfs_super_flags(disk_super) &
~BTRFS_SUPER_FLAG_SEEDING;
btrfs_set_super_flags(disk_super, super_flags);
return 0;
}
/*
* Store the expected generation for seed devices in device items.
*/
static int btrfs_finish_sprout(struct btrfs_trans_handle *trans)
{
struct btrfs_fs_info *fs_info = trans->fs_info;
struct btrfs_root *root = fs_info->chunk_root;
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_dev_item *dev_item;
struct btrfs_device *device;
struct btrfs_key key;
u8 fs_uuid[BTRFS_FSID_SIZE];
u8 dev_uuid[BTRFS_UUID_SIZE];
u64 devid;
int ret;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
key.offset = 0;
key.type = BTRFS_DEV_ITEM_KEY;
while (1) {
ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
if (ret < 0)
goto error;
leaf = path->nodes[0];
next_slot:
if (path->slots[0] >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, path);
if (ret > 0)
break;
if (ret < 0)
goto error;
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
btrfs_release_path(path);
continue;
}
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
if (key.objectid != BTRFS_DEV_ITEMS_OBJECTID ||
key.type != BTRFS_DEV_ITEM_KEY)
break;
dev_item = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_dev_item);
devid = btrfs_device_id(leaf, dev_item);
read_extent_buffer(leaf, dev_uuid, btrfs_device_uuid(dev_item),
BTRFS_UUID_SIZE);
read_extent_buffer(leaf, fs_uuid, btrfs_device_fsid(dev_item),
BTRFS_FSID_SIZE);
device = btrfs_find_device(fs_info->fs_devices, devid, dev_uuid,
fs_uuid, true);
BUG_ON(!device); /* Logic error */
if (device->fs_devices->seeding) {
btrfs_set_device_generation(leaf, dev_item,
device->generation);
btrfs_mark_buffer_dirty(leaf);
}
path->slots[0]++;
goto next_slot;
}
ret = 0;
error:
btrfs_free_path(path);
return ret;
}
int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *device_path)
{
struct btrfs_root *root = fs_info->dev_root;
struct request_queue *q;
struct btrfs_trans_handle *trans;
struct btrfs_device *device;
struct block_device *bdev;
struct super_block *sb = fs_info->sb;
struct rcu_string *name;
struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
u64 orig_super_total_bytes;
u64 orig_super_num_devices;
int seeding_dev = 0;
int ret = 0;
bool unlocked = false;
if (sb_rdonly(sb) && !fs_devices->seeding)
return -EROFS;
bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL,
fs_info->bdev_holder);
if (IS_ERR(bdev))
return PTR_ERR(bdev);
if (fs_devices->seeding) {
seeding_dev = 1;
down_write(&sb->s_umount);
mutex_lock(&uuid_mutex);
}
filemap_write_and_wait(bdev->bd_inode->i_mapping);
mutex_lock(&fs_devices->device_list_mutex);
list_for_each_entry(device, &fs_devices->devices, dev_list) {
if (device->bdev == bdev) {
ret = -EEXIST;
mutex_unlock(
&fs_devices->device_list_mutex);
goto error;
}
}
mutex_unlock(&fs_devices->device_list_mutex);
device = btrfs_alloc_device(fs_info, NULL, NULL);
if (IS_ERR(device)) {
/* we can safely leave the fs_devices entry around */
ret = PTR_ERR(device);
goto error;
}
name = rcu_string_strdup(device_path, GFP_KERNEL);
if (!name) {
ret = -ENOMEM;
goto error_free_device;
}
rcu_assign_pointer(device->name, name);
trans = btrfs_start_transaction(root, 0);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
goto error_free_device;
}
q = bdev_get_queue(bdev);
set_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
device->generation = trans->transid;
device->io_width = fs_info->sectorsize;
device->io_align = fs_info->sectorsize;
device->sector_size = fs_info->sectorsize;
device->total_bytes = round_down(i_size_read(bdev->bd_inode),
fs_info->sectorsize);
device->disk_total_bytes = device->total_bytes;
device->commit_total_bytes = device->total_bytes;
device->fs_info = fs_info;
device->bdev = bdev;
set_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
clear_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state);
device->mode = FMODE_EXCL;
device->dev_stats_valid = 1;
set_blocksize(device->bdev, BTRFS_BDEV_BLOCKSIZE);
if (seeding_dev) {
sb->s_flags &= ~SB_RDONLY;
ret = btrfs_prepare_sprout(fs_info);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto error_trans;
}
}
device->fs_devices = fs_devices;
mutex_lock(&fs_devices->device_list_mutex);
mutex_lock(&fs_info->chunk_mutex);
list_add_rcu(&device->dev_list, &fs_devices->devices);
list_add(&device->dev_alloc_list, &fs_devices->alloc_list);
fs_devices->num_devices++;
fs_devices->open_devices++;
fs_devices->rw_devices++;
fs_devices->total_devices++;
fs_devices->total_rw_bytes += device->total_bytes;
atomic64_add(device->total_bytes, &fs_info->free_chunk_space);
if (!blk_queue_nonrot(q))
fs_devices->rotating = true;
orig_super_total_bytes = btrfs_super_total_bytes(fs_info->super_copy);
btrfs_set_super_total_bytes(fs_info->super_copy,
round_down(orig_super_total_bytes + device->total_bytes,
fs_info->sectorsize));
orig_super_num_devices = btrfs_super_num_devices(fs_info->super_copy);
btrfs_set_super_num_devices(fs_info->super_copy,
orig_super_num_devices + 1);
/* add sysfs device entry */
btrfs_sysfs_add_devices_dir(fs_devices, device);
/*
* we've got more storage, clear any full flags on the space
* infos
*/
btrfs_clear_space_info_full(fs_info);
mutex_unlock(&fs_info->chunk_mutex);
mutex_unlock(&fs_devices->device_list_mutex);
if (seeding_dev) {
mutex_lock(&fs_info->chunk_mutex);
ret = init_first_rw_device(trans);
mutex_unlock(&fs_info->chunk_mutex);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto error_sysfs;
}
}
ret = btrfs_add_dev_item(trans, device);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto error_sysfs;
}
if (seeding_dev) {
ret = btrfs_finish_sprout(trans);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto error_sysfs;
}
btrfs_sysfs_update_sprout_fsid(fs_devices,
fs_info->fs_devices->fsid);
}
ret = btrfs_commit_transaction(trans);
if (seeding_dev) {
mutex_unlock(&uuid_mutex);
up_write(&sb->s_umount);
unlocked = true;
if (ret) /* transaction commit */
return ret;
ret = btrfs_relocate_sys_chunks(fs_info);
if (ret < 0)
btrfs_handle_fs_error(fs_info, ret,
"Failed to relocate sys chunks after device initialization. This can be fixed using the \"btrfs balance\" command.");
trans = btrfs_attach_transaction(root);
if (IS_ERR(trans)) {
if (PTR_ERR(trans) == -ENOENT)
return 0;
ret = PTR_ERR(trans);
trans = NULL;
goto error_sysfs;
}
ret = btrfs_commit_transaction(trans);
}
/* Update ctime/mtime for libblkid */
update_dev_time(device_path);
return ret;
error_sysfs:
btrfs_sysfs_remove_devices_dir(fs_devices, device);
mutex_lock(&fs_info->fs_devices->device_list_mutex);
mutex_lock(&fs_info->chunk_mutex);
list_del_rcu(&device->dev_list);
list_del(&device->dev_alloc_list);
fs_info->fs_devices->num_devices--;
fs_info->fs_devices->open_devices--;
fs_info->fs_devices->rw_devices--;
fs_info->fs_devices->total_devices--;
fs_info->fs_devices->total_rw_bytes -= device->total_bytes;
atomic64_sub(device->total_bytes, &fs_info->free_chunk_space);
btrfs_set_super_total_bytes(fs_info->super_copy,
orig_super_total_bytes);
btrfs_set_super_num_devices(fs_info->super_copy,
orig_super_num_devices);
mutex_unlock(&fs_info->chunk_mutex);
mutex_unlock(&fs_info->fs_devices->device_list_mutex);
error_trans:
if (seeding_dev)
sb->s_flags |= SB_RDONLY;
if (trans)
btrfs_end_transaction(trans);
error_free_device:
btrfs_free_device(device);
error:
blkdev_put(bdev, FMODE_EXCL);
if (seeding_dev && !unlocked) {
mutex_unlock(&uuid_mutex);
up_write(&sb->s_umount);
}
return ret;
}
static noinline int btrfs_update_device(struct btrfs_trans_handle *trans,
struct btrfs_device *device)
{
int ret;
struct btrfs_path *path;
struct btrfs_root *root = device->fs_info->chunk_root;
struct btrfs_dev_item *dev_item;
struct extent_buffer *leaf;
struct btrfs_key key;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
key.type = BTRFS_DEV_ITEM_KEY;
key.offset = device->devid;
ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
if (ret < 0)
goto out;
if (ret > 0) {
ret = -ENOENT;
goto out;
}
leaf = path->nodes[0];
dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
btrfs_set_device_id(leaf, dev_item, device->devid);
btrfs_set_device_type(leaf, dev_item, device->type);
btrfs_set_device_io_align(leaf, dev_item, device->io_align);
btrfs_set_device_io_width(leaf, dev_item, device->io_width);
btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
btrfs_set_device_total_bytes(leaf, dev_item,
btrfs_device_get_disk_total_bytes(device));
btrfs_set_device_bytes_used(leaf, dev_item,
btrfs_device_get_bytes_used(device));
btrfs_mark_buffer_dirty(leaf);
out:
btrfs_free_path(path);
return ret;
}
int btrfs_grow_device(struct btrfs_trans_handle *trans,
struct btrfs_device *device, u64 new_size)
{
struct btrfs_fs_info *fs_info = device->fs_info;
struct btrfs_super_block *super_copy = fs_info->super_copy;
u64 old_total;
u64 diff;
if (!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state))
return -EACCES;
new_size = round_down(new_size, fs_info->sectorsize);
mutex_lock(&fs_info->chunk_mutex);
old_total = btrfs_super_total_bytes(super_copy);
diff = round_down(new_size - device->total_bytes, fs_info->sectorsize);
if (new_size <= device->total_bytes ||
test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) {
mutex_unlock(&fs_info->chunk_mutex);
return -EINVAL;
}
btrfs_set_super_total_bytes(super_copy,
round_down(old_total + diff, fs_info->sectorsize));
device->fs_devices->total_rw_bytes += diff;
btrfs_device_set_total_bytes(device, new_size);
btrfs_device_set_disk_total_bytes(device, new_size);
btrfs_clear_space_info_full(device->fs_info);
if (list_empty(&device->post_commit_list))
list_add_tail(&device->post_commit_list,
&trans->transaction->dev_update_list);
mutex_unlock(&fs_info->chunk_mutex);
return btrfs_update_device(trans, device);
}
static int btrfs_free_chunk(struct btrfs_trans_handle *trans, u64 chunk_offset)
{
struct btrfs_fs_info *fs_info = trans->fs_info;
struct btrfs_root *root = fs_info->chunk_root;
int ret;
struct btrfs_path *path;
struct btrfs_key key;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
key.offset = chunk_offset;
key.type = BTRFS_CHUNK_ITEM_KEY;
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret < 0)
goto out;
else if (ret > 0) { /* Logic error or corruption */
btrfs_handle_fs_error(fs_info, -ENOENT,
"Failed lookup while freeing chunk.");
ret = -ENOENT;
goto out;
}
ret = btrfs_del_item(trans, root, path);
if (ret < 0)
btrfs_handle_fs_error(fs_info, ret,
"Failed to delete chunk item.");
out:
btrfs_free_path(path);
return ret;
}
static int btrfs_del_sys_chunk(struct btrfs_fs_info *fs_info, u64 chunk_offset)
{
struct btrfs_super_block *super_copy = fs_info->super_copy;
struct btrfs_disk_key *disk_key;
struct btrfs_chunk *chunk;
u8 *ptr;
int ret = 0;
u32 num_stripes;
u32 array_size;
u32 len = 0;
u32 cur;
struct btrfs_key key;
mutex_lock(&fs_info->chunk_mutex);
array_size = btrfs_super_sys_array_size(super_copy);
ptr = super_copy->sys_chunk_array;
cur = 0;
while (cur < array_size) {
disk_key = (struct btrfs_disk_key *)ptr;
btrfs_disk_key_to_cpu(&key, disk_key);
len = sizeof(*disk_key);
if (key.type == BTRFS_CHUNK_ITEM_KEY) {
chunk = (struct btrfs_chunk *)(ptr + len);
num_stripes = btrfs_stack_chunk_num_stripes(chunk);
len += btrfs_chunk_item_size(num_stripes);
} else {
ret = -EIO;
break;
}
if (key.objectid == BTRFS_FIRST_CHUNK_TREE_OBJECTID &&
key.offset == chunk_offset) {
memmove(ptr, ptr + len, array_size - (cur + len));
array_size -= len;
btrfs_set_super_sys_array_size(super_copy, array_size);
} else {
ptr += len;
cur += len;
}
}
mutex_unlock(&fs_info->chunk_mutex);
return ret;
}
/*
* btrfs_get_chunk_map() - Find the mapping containing the given logical extent.
* @logical: Logical block offset in bytes.
* @length: Length of extent in bytes.
*
* Return: Chunk mapping or ERR_PTR.
*/
struct extent_map *btrfs_get_chunk_map(struct btrfs_fs_info *fs_info,
u64 logical, u64 length)
{
struct extent_map_tree *em_tree;
struct extent_map *em;
em_tree = &fs_info->mapping_tree;
read_lock(&em_tree->lock);
em = lookup_extent_mapping(em_tree, logical, length);
read_unlock(&em_tree->lock);
if (!em) {
btrfs_crit(fs_info, "unable to find logical %llu length %llu",
logical, length);
return ERR_PTR(-EINVAL);
}
if (em->start > logical || em->start + em->len < logical) {
btrfs_crit(fs_info,
"found a bad mapping, wanted %llu-%llu, found %llu-%llu",
logical, length, em->start, em->start + em->len);
free_extent_map(em);
return ERR_PTR(-EINVAL);
}
/* callers are responsible for dropping em's ref. */
return em;
}
int btrfs_remove_chunk(struct btrfs_trans_handle *trans, u64 chunk_offset)
{
struct btrfs_fs_info *fs_info = trans->fs_info;
struct extent_map *em;
struct map_lookup *map;
u64 dev_extent_len = 0;
int i, ret = 0;
struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
em = btrfs_get_chunk_map(fs_info, chunk_offset, 1);
if (IS_ERR(em)) {
/*
* This is a logic error, but we don't want to just rely on the
* user having built with ASSERT enabled, so if ASSERT doesn't
* do anything we still error out.
*/
ASSERT(0);
return PTR_ERR(em);
}
map = em->map_lookup;
mutex_lock(&fs_info->chunk_mutex);
check_system_chunk(trans, map->type);
mutex_unlock(&fs_info->chunk_mutex);
/*
* Take the device list mutex to prevent races with the final phase of
* a device replace operation that replaces the device object associated
* with map stripes (dev-replace.c:btrfs_dev_replace_finishing()).
*/
mutex_lock(&fs_devices->device_list_mutex);
for (i = 0; i < map->num_stripes; i++) {
struct btrfs_device *device = map->stripes[i].dev;
ret = btrfs_free_dev_extent(trans, device,
map->stripes[i].physical,
&dev_extent_len);
if (ret) {
mutex_unlock(&fs_devices->device_list_mutex);
btrfs_abort_transaction(trans, ret);
goto out;
}
if (device->bytes_used > 0) {
mutex_lock(&fs_info->chunk_mutex);
btrfs_device_set_bytes_used(device,
device->bytes_used - dev_extent_len);
atomic64_add(dev_extent_len, &fs_info->free_chunk_space);
btrfs_clear_space_info_full(fs_info);
mutex_unlock(&fs_info->chunk_mutex);
}
ret = btrfs_update_device(trans, device);
if (ret) {
mutex_unlock(&fs_devices->device_list_mutex);
btrfs_abort_transaction(trans, ret);
goto out;
}
}
mutex_unlock(&fs_devices->device_list_mutex);
ret = btrfs_free_chunk(trans, chunk_offset);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out;
}
trace_btrfs_chunk_free(fs_info, map, chunk_offset, em->len);
if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
ret = btrfs_del_sys_chunk(fs_info, chunk_offset);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out;
}
}
ret = btrfs_remove_block_group(trans, chunk_offset, em);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out;
}
out:
/* once for us */
free_extent_map(em);
return ret;
}
static int btrfs_relocate_chunk(struct btrfs_fs_info *fs_info, u64 chunk_offset)
{
struct btrfs_root *root = fs_info->chunk_root;
struct btrfs_trans_handle *trans;
struct btrfs_block_group *block_group;
int ret;
/*
* Prevent races with automatic removal of unused block groups.
* After we relocate and before we remove the chunk with offset
* chunk_offset, automatic removal of the block group can kick in,
* resulting in a failure when calling btrfs_remove_chunk() below.
*
* Make sure to acquire this mutex before doing a tree search (dev
* or chunk trees) to find chunks. Otherwise the cleaner kthread might
* call btrfs_remove_chunk() (through btrfs_delete_unused_bgs()) after
* we release the path used to search the chunk/dev tree and before
* the current task acquires this mutex and calls us.
*/
lockdep_assert_held(&fs_info->delete_unused_bgs_mutex);
/* step one, relocate all the extents inside this chunk */
btrfs_scrub_pause(fs_info);
ret = btrfs_relocate_block_group(fs_info, chunk_offset);
btrfs_scrub_continue(fs_info);
if (ret)
return ret;
block_group = btrfs_lookup_block_group(fs_info, chunk_offset);
if (!block_group)
return -ENOENT;
btrfs_discard_cancel_work(&fs_info->discard_ctl, block_group);
btrfs_put_block_group(block_group);
trans = btrfs_start_trans_remove_block_group(root->fs_info,
chunk_offset);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
btrfs_handle_fs_error(root->fs_info, ret, NULL);
return ret;
}
/*
* step two, delete the device extents and the
* chunk tree entries
*/
ret = btrfs_remove_chunk(trans, chunk_offset);
btrfs_end_transaction(trans);
return ret;
}
static int btrfs_relocate_sys_chunks(struct btrfs_fs_info *fs_info)
{
struct btrfs_root *chunk_root = fs_info->chunk_root;
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_chunk *chunk;
struct btrfs_key key;
struct btrfs_key found_key;
u64 chunk_type;
bool retried = false;
int failed = 0;
int ret;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
again:
key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
key.offset = (u64)-1;
key.type = BTRFS_CHUNK_ITEM_KEY;
while (1) {
mutex_lock(&fs_info->delete_unused_bgs_mutex);
ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
if (ret < 0) {
mutex_unlock(&fs_info->delete_unused_bgs_mutex);
goto error;
}
BUG_ON(ret == 0); /* Corruption */
ret = btrfs_previous_item(chunk_root, path, key.objectid,
key.type);
if (ret)
mutex_unlock(&fs_info->delete_unused_bgs_mutex);
if (ret < 0)
goto error;
if (ret > 0)
break;
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
chunk = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_chunk);
chunk_type = btrfs_chunk_type(leaf, chunk);
btrfs_release_path(path);
if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) {
ret = btrfs_relocate_chunk(fs_info, found_key.offset);
if (ret == -ENOSPC)
failed++;
else
BUG_ON(ret);
}
mutex_unlock(&fs_info->delete_unused_bgs_mutex);
if (found_key.offset == 0)
break;
key.offset = found_key.offset - 1;
}
ret = 0;
if (failed && !retried) {
failed = 0;
retried = true;
goto again;
} else if (WARN_ON(failed && retried)) {
ret = -ENOSPC;
}
error:
btrfs_free_path(path);
return ret;
}
/*
* return 1 : allocate a data chunk successfully,
* return <0: errors during allocating a data chunk,
* return 0 : no need to allocate a data chunk.
*/
static int btrfs_may_alloc_data_chunk(struct btrfs_fs_info *fs_info,
u64 chunk_offset)
{
struct btrfs_block_group *cache;
u64 bytes_used;
u64 chunk_type;
cache = btrfs_lookup_block_group(fs_info, chunk_offset);
ASSERT(cache);
chunk_type = cache->flags;
btrfs_put_block_group(cache);
if (!(chunk_type & BTRFS_BLOCK_GROUP_DATA))
return 0;
spin_lock(&fs_info->data_sinfo->lock);
bytes_used = fs_info->data_sinfo->bytes_used;
spin_unlock(&fs_info->data_sinfo->lock);
if (!bytes_used) {
struct btrfs_trans_handle *trans;
int ret;
trans = btrfs_join_transaction(fs_info->tree_root);
if (IS_ERR(trans))
return PTR_ERR(trans);
ret = btrfs_force_chunk_alloc(trans, BTRFS_BLOCK_GROUP_DATA);
btrfs_end_transaction(trans);
if (ret < 0)
return ret;
return 1;
}
return 0;
}
static int insert_balance_item(struct btrfs_fs_info *fs_info,
struct btrfs_balance_control *bctl)
{
struct btrfs_root *root = fs_info->tree_root;
struct btrfs_trans_handle *trans;
struct btrfs_balance_item *item;
struct btrfs_disk_balance_args disk_bargs;
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_key key;
int ret, err;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
trans = btrfs_start_transaction(root, 0);
if (IS_ERR(trans)) {
btrfs_free_path(path);
return PTR_ERR(trans);
}
key.objectid = BTRFS_BALANCE_OBJECTID;
key.type = BTRFS_TEMPORARY_ITEM_KEY;
key.offset = 0;
ret = btrfs_insert_empty_item(trans, root, path, &key,
sizeof(*item));
if (ret)
goto out;
leaf = path->nodes[0];
item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
memzero_extent_buffer(leaf, (unsigned long)item, sizeof(*item));
btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->data);
btrfs_set_balance_data(leaf, item, &disk_bargs);
btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->meta);
btrfs_set_balance_meta(leaf, item, &disk_bargs);
btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->sys);
btrfs_set_balance_sys(leaf, item, &disk_bargs);
btrfs_set_balance_flags(leaf, item, bctl->flags);
btrfs_mark_buffer_dirty(leaf);
out:
btrfs_free_path(path);
err = btrfs_commit_transaction(trans);
if (err && !ret)
ret = err;
return ret;
}
static int del_balance_item(struct btrfs_fs_info *fs_info)
{
struct btrfs_root *root = fs_info->tree_root;
struct btrfs_trans_handle *trans;
struct btrfs_path *path;
struct btrfs_key key;
int ret, err;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
trans = btrfs_start_transaction(root, 0);
if (IS_ERR(trans)) {
btrfs_free_path(path);
return PTR_ERR(trans);
}
key.objectid = BTRFS_BALANCE_OBJECTID;
key.type = BTRFS_TEMPORARY_ITEM_KEY;
key.offset = 0;
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret < 0)
goto out;
if (ret > 0) {
ret = -ENOENT;
goto out;
}
ret = btrfs_del_item(trans, root, path);
out:
btrfs_free_path(path);
err = btrfs_commit_transaction(trans);
if (err && !ret)
ret = err;
return ret;
}
/*
* This is a heuristic used to reduce the number of chunks balanced on
* resume after balance was interrupted.
*/
static void update_balance_args(struct btrfs_balance_control *bctl)
{
/*
* Turn on soft mode for chunk types that were being converted.
*/
if (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)
bctl->data.flags |= BTRFS_BALANCE_ARGS_SOFT;
if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)
bctl->sys.flags |= BTRFS_BALANCE_ARGS_SOFT;
if (bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)
bctl->meta.flags |= BTRFS_BALANCE_ARGS_SOFT;
/*
* Turn on usage filter if is not already used. The idea is
* that chunks that we have already balanced should be
* reasonably full. Don't do it for chunks that are being
* converted - that will keep us from relocating unconverted
* (albeit full) chunks.
*/
if (!(bctl->data.flags & BTRFS_BALANCE_ARGS_USAGE) &&
!(bctl->data.flags & BTRFS_BALANCE_ARGS_USAGE_RANGE) &&
!(bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
bctl->data.flags |= BTRFS_BALANCE_ARGS_USAGE;
bctl->data.usage = 90;
}
if (!(bctl->sys.flags & BTRFS_BALANCE_ARGS_USAGE) &&
!(bctl->sys.flags & BTRFS_BALANCE_ARGS_USAGE_RANGE) &&
!(bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
bctl->sys.flags |= BTRFS_BALANCE_ARGS_USAGE;
bctl->sys.usage = 90;
}
if (!(bctl->meta.flags & BTRFS_BALANCE_ARGS_USAGE) &&
!(bctl->meta.flags & BTRFS_BALANCE_ARGS_USAGE_RANGE) &&
!(bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
bctl->meta.flags |= BTRFS_BALANCE_ARGS_USAGE;
bctl->meta.usage = 90;
}
}
/*
* Clear the balance status in fs_info and delete the balance item from disk.
*/
static void reset_balance_state(struct btrfs_fs_info *fs_info)
{
struct btrfs_balance_control *bctl = fs_info->balance_ctl;
int ret;
BUG_ON(!fs_info->balance_ctl);
spin_lock(&fs_info->balance_lock);
fs_info->balance_ctl = NULL;
spin_unlock(&fs_info->balance_lock);
kfree(bctl);
ret = del_balance_item(fs_info);
if (ret)
btrfs_handle_fs_error(fs_info, ret, NULL);
}
/*
* Balance filters. Return 1 if chunk should be filtered out
* (should not be balanced).
*/
static int chunk_profiles_filter(u64 chunk_type,
struct btrfs_balance_args *bargs)
{
chunk_type = chunk_to_extended(chunk_type) &
BTRFS_EXTENDED_PROFILE_MASK;
if (bargs->profiles & chunk_type)
return 0;
return 1;
}
static int chunk_usage_range_filter(struct btrfs_fs_info *fs_info, u64 chunk_offset,
struct btrfs_balance_args *bargs)
{
struct btrfs_block_group *cache;
u64 chunk_used;
u64 user_thresh_min;
u64 user_thresh_max;
int ret = 1;
cache = btrfs_lookup_block_group(fs_info, chunk_offset);
chunk_used = cache->used;
if (bargs->usage_min == 0)
user_thresh_min = 0;
else
user_thresh_min = div_factor_fine(cache->length,
bargs->usage_min);
if (bargs->usage_max == 0)
user_thresh_max = 1;
else if (bargs->usage_max > 100)
user_thresh_max = cache->length;
else
user_thresh_max = div_factor_fine(cache->length,
bargs->usage_max);
if (user_thresh_min <= chunk_used && chunk_used < user_thresh_max)
ret = 0;
btrfs_put_block_group(cache);
return ret;
}
static int chunk_usage_filter(struct btrfs_fs_info *fs_info,
u64 chunk_offset, struct btrfs_balance_args *bargs)
{
struct btrfs_block_group *cache;
u64 chunk_used, user_thresh;
int ret = 1;
cache = btrfs_lookup_block_group(fs_info, chunk_offset);
chunk_used = cache->used;
if (bargs->usage_min == 0)
user_thresh = 1;
else if (bargs->usage > 100)
user_thresh = cache->length;
else
user_thresh = div_factor_fine(cache->length, bargs->usage);
if (chunk_used < user_thresh)
ret = 0;
btrfs_put_block_group(cache);
return ret;
}
static int chunk_devid_filter(struct extent_buffer *leaf,
struct btrfs_chunk *chunk,
struct btrfs_balance_args *bargs)
{
struct btrfs_stripe *stripe;
int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
int i;
for (i = 0; i < num_stripes; i++) {
stripe = btrfs_stripe_nr(chunk, i);
if (btrfs_stripe_devid(leaf, stripe) == bargs->devid)
return 0;
}
return 1;
}
static u64 calc_data_stripes(u64 type, int num_stripes)
{
const int index = btrfs_bg_flags_to_raid_index(type);
const int ncopies = btrfs_raid_array[index].ncopies;
const int nparity = btrfs_raid_array[index].nparity;
if (nparity)
return num_stripes - nparity;
else
return num_stripes / ncopies;
}
/* [pstart, pend) */
static int chunk_drange_filter(struct extent_buffer *leaf,
struct btrfs_chunk *chunk,
struct btrfs_balance_args *bargs)
{
struct btrfs_stripe *stripe;
int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
u64 stripe_offset;
u64 stripe_length;
u64 type;
int factor;
int i;
if (!(bargs->flags & BTRFS_BALANCE_ARGS_DEVID))
return 0;
type = btrfs_chunk_type(leaf, chunk);
factor = calc_data_stripes(type, num_stripes);
for (i = 0; i < num_stripes; i++) {
stripe = btrfs_stripe_nr(chunk, i);
if (btrfs_stripe_devid(leaf, stripe) != bargs->devid)
continue;
stripe_offset = btrfs_stripe_offset(leaf, stripe);
stripe_length = btrfs_chunk_length(leaf, chunk);
stripe_length = div_u64(stripe_length, factor);
if (stripe_offset < bargs->pend &&
stripe_offset + stripe_length > bargs->pstart)
return 0;
}
return 1;
}
/* [vstart, vend) */
static int chunk_vrange_filter(struct extent_buffer *leaf,
struct btrfs_chunk *chunk,
u64 chunk_offset,
struct btrfs_balance_args *bargs)
{
if (chunk_offset < bargs->vend &&
chunk_offset + btrfs_chunk_length(leaf, chunk) > bargs->vstart)
/* at least part of the chunk is inside this vrange */
return 0;
return 1;
}
static int chunk_stripes_range_filter(struct extent_buffer *leaf,
struct btrfs_chunk *chunk,
struct btrfs_balance_args *bargs)
{
int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
if (bargs->stripes_min <= num_stripes
&& num_stripes <= bargs->stripes_max)
return 0;
return 1;
}
static int chunk_soft_convert_filter(u64 chunk_type,
struct btrfs_balance_args *bargs)
{
if (!(bargs->flags & BTRFS_BALANCE_ARGS_CONVERT))
return 0;
chunk_type = chunk_to_extended(chunk_type) &
BTRFS_EXTENDED_PROFILE_MASK;
if (bargs->target == chunk_type)
return 1;
return 0;
}
static int should_balance_chunk(struct extent_buffer *leaf,
struct btrfs_chunk *chunk, u64 chunk_offset)
{
struct btrfs_fs_info *fs_info = leaf->fs_info;
struct btrfs_balance_control *bctl = fs_info->balance_ctl;
struct btrfs_balance_args *bargs = NULL;
u64 chunk_type = btrfs_chunk_type(leaf, chunk);
/* type filter */
if (!((chunk_type & BTRFS_BLOCK_GROUP_TYPE_MASK) &
(bctl->flags & BTRFS_BALANCE_TYPE_MASK))) {
return 0;
}
if (chunk_type & BTRFS_BLOCK_GROUP_DATA)
bargs = &bctl->data;
else if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM)
bargs = &bctl->sys;
else if (chunk_type & BTRFS_BLOCK_GROUP_METADATA)
bargs = &bctl->meta;
/* profiles filter */
if ((bargs->flags & BTRFS_BALANCE_ARGS_PROFILES) &&
chunk_profiles_filter(chunk_type, bargs)) {
return 0;
}
/* usage filter */
if ((bargs->flags & BTRFS_BALANCE_ARGS_USAGE) &&
chunk_usage_filter(fs_info, chunk_offset, bargs)) {
return 0;
} else if ((bargs->flags & BTRFS_BALANCE_ARGS_USAGE_RANGE) &&
chunk_usage_range_filter(fs_info, chunk_offset, bargs)) {
return 0;
}
/* devid filter */
if ((bargs->flags & BTRFS_BALANCE_ARGS_DEVID) &&
chunk_devid_filter(leaf, chunk, bargs)) {
return 0;
}
/* drange filter, makes sense only with devid filter */
if ((bargs->flags & BTRFS_BALANCE_ARGS_DRANGE) &&
chunk_drange_filter(leaf, chunk, bargs)) {
return 0;
}
/* vrange filter */
if ((bargs->flags & BTRFS_BALANCE_ARGS_VRANGE) &&
chunk_vrange_filter(leaf, chunk, chunk_offset, bargs)) {
return 0;
}
/* stripes filter */
if ((bargs->flags & BTRFS_BALANCE_ARGS_STRIPES_RANGE) &&
chunk_stripes_range_filter(leaf, chunk, bargs)) {
return 0;
}
/* soft profile changing mode */
if ((bargs->flags & BTRFS_BALANCE_ARGS_SOFT) &&
chunk_soft_convert_filter(chunk_type, bargs)) {
return 0;
}
/*
* limited by count, must be the last filter
*/
if ((bargs->flags & BTRFS_BALANCE_ARGS_LIMIT)) {
if (bargs->limit == 0)
return 0;
else
bargs->limit--;
} else if ((bargs->flags & BTRFS_BALANCE_ARGS_LIMIT_RANGE)) {
/*
* Same logic as the 'limit' filter; the minimum cannot be
* determined here because we do not have the global information
* about the count of all chunks that satisfy the filters.
*/
if (bargs->limit_max == 0)
return 0;
else
bargs->limit_max--;
}
return 1;
}
static int __btrfs_balance(struct btrfs_fs_info *fs_info)
{
struct btrfs_balance_control *bctl = fs_info->balance_ctl;
struct btrfs_root *chunk_root = fs_info->chunk_root;
u64 chunk_type;
struct btrfs_chunk *chunk;
struct btrfs_path *path = NULL;
struct btrfs_key key;
struct btrfs_key found_key;
struct extent_buffer *leaf;
int slot;
int ret;
int enospc_errors = 0;
bool counting = true;
/* The single value limit and min/max limits use the same bytes in the */
u64 limit_data = bctl->data.limit;
u64 limit_meta = bctl->meta.limit;
u64 limit_sys = bctl->sys.limit;
u32 count_data = 0;
u32 count_meta = 0;
u32 count_sys = 0;
int chunk_reserved = 0;
path = btrfs_alloc_path();
if (!path) {
ret = -ENOMEM;
goto error;
}
/* zero out stat counters */
spin_lock(&fs_info->balance_lock);
memset(&bctl->stat, 0, sizeof(bctl->stat));
spin_unlock(&fs_info->balance_lock);
again:
if (!counting) {
/*
* The single value limit and min/max limits use the same bytes
* in the
*/
bctl->data.limit = limit_data;
bctl->meta.limit = limit_meta;
bctl->sys.limit = limit_sys;
}
key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
key.offset = (u64)-1;
key.type = BTRFS_CHUNK_ITEM_KEY;
while (1) {
if ((!counting && atomic_read(&fs_info->balance_pause_req)) ||
atomic_read(&fs_info->balance_cancel_req)) {
ret = -ECANCELED;
goto error;
}
mutex_lock(&fs_info->delete_unused_bgs_mutex);
ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
if (ret < 0) {
mutex_unlock(&fs_info->delete_unused_bgs_mutex);
goto error;
}
/*
* this shouldn't happen, it means the last relocate
* failed
*/
if (ret == 0)
BUG(); /* FIXME break ? */
ret = btrfs_previous_item(chunk_root, path, 0,
BTRFS_CHUNK_ITEM_KEY);
if (ret) {
mutex_unlock(&fs_info->delete_unused_bgs_mutex);
ret = 0;
break;
}
leaf = path->nodes[0];
slot = path->slots[0];
btrfs_item_key_to_cpu(leaf, &found_key, slot);
if (found_key.objectid != key.objectid) {
mutex_unlock(&fs_info->delete_unused_bgs_mutex);
break;
}
chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
chunk_type = btrfs_chunk_type(leaf, chunk);
if (!counting) {
spin_lock(&fs_info->balance_lock);
bctl->stat.considered++;
spin_unlock(&fs_info->balance_lock);
}
ret = should_balance_chunk(leaf, chunk, found_key.offset);
btrfs_release_path(path);
if (!ret) {
mutex_unlock(&fs_info->delete_unused_bgs_mutex);
goto loop;
}
if (counting) {
mutex_unlock(&fs_info->delete_unused_bgs_mutex);
spin_lock(&fs_info->balance_lock);
bctl->stat.expected++;
spin_unlock(&fs_info->balance_lock);
if (chunk_type & BTRFS_BLOCK_GROUP_DATA)
count_data++;
else if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM)
count_sys++;
else if (chunk_type & BTRFS_BLOCK_GROUP_METADATA)
count_meta++;
goto loop;
}
/*
* Apply limit_min filter, no need to check if the LIMITS
* filter is used, limit_min is 0 by default
*/
if (((chunk_type & BTRFS_BLOCK_GROUP_DATA) &&
count_data < bctl->data.limit_min)
|| ((chunk_type & BTRFS_BLOCK_GROUP_METADATA) &&
count_meta < bctl->meta.limit_min)
|| ((chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) &&
count_sys < bctl->sys.limit_min)) {
mutex_unlock(&fs_info->delete_unused_bgs_mutex);
goto loop;
}
if (!chunk_reserved) {
/*
* We may be relocating the only data chunk we have,
* which could potentially end up with losing data's
* raid profile, so lets allocate an empty one in
* advance.
*/
ret = btrfs_may_alloc_data_chunk(fs_info,
found_key.offset);
if (ret < 0) {
mutex_unlock(&fs_info->delete_unused_bgs_mutex);
goto error;
} else if (ret == 1) {
chunk_reserved = 1;
}
}
ret = btrfs_relocate_chunk(fs_info, found_key.offset);
mutex_unlock(&fs_info->delete_unused_bgs_mutex);
if (ret == -ENOSPC) {
enospc_errors++;
} else if (ret == -ETXTBSY) {
btrfs_info(fs_info,
"skipping relocation of block group %llu due to active swapfile",
found_key.offset);
ret = 0;
} else if (ret) {
goto error;
} else {
spin_lock(&fs_info->balance_lock);
bctl->stat.completed++;
spin_unlock(&fs_info->balance_lock);
}
loop:
if (found_key.offset == 0)
break;
key.offset = found_key.offset - 1;
}
if (counting) {
btrfs_release_path(path);
counting = false;
goto again;
}
error:
btrfs_free_path(path);
if (enospc_errors) {
btrfs_info(fs_info, "%d enospc errors during balance",
enospc_errors);
if (!ret)
ret = -ENOSPC;
}
return ret;
}
/**
* alloc_profile_is_valid - see if a given profile is valid and reduced
* @flags: profile to validate
* @extended: if true @flags is treated as an extended profile
*/
static int alloc_profile_is_valid(u64 flags, int extended)
{
u64 mask = (extended ? BTRFS_EXTENDED_PROFILE_MASK :
BTRFS_BLOCK_GROUP_PROFILE_MASK);
flags &= ~BTRFS_BLOCK_GROUP_TYPE_MASK;
/* 1) check that all other bits are zeroed */
if (flags & ~mask)
return 0;
/* 2) see if profile is reduced */
if (flags == 0)
return !extended; /* "0" is valid for usual profiles */
return has_single_bit_set(flags);
}
static inline int balance_need_close(struct btrfs_fs_info *fs_info)
{
/* cancel requested || normal exit path */
return atomic_read(&fs_info->balance_cancel_req) ||
(atomic_read(&fs_info->balance_pause_req) == 0 &&
atomic_read(&fs_info->balance_cancel_req) == 0);
}
/*
* Validate target profile against allowed profiles and return true if it's OK.
* Otherwise print the error message and return false.
*/
static inline int validate_convert_profile(struct btrfs_fs_info *fs_info,
const struct btrfs_balance_args *bargs,
u64 allowed, const char *type)
{
if (!(bargs->flags & BTRFS_BALANCE_ARGS_CONVERT))
return true;
/* Profile is valid and does not have bits outside of the allowed set */
if (alloc_profile_is_valid(bargs->target, 1) &&
(bargs->target & ~allowed) == 0)
return true;
btrfs_err(fs_info, "balance: invalid convert %s profile %s",
type, btrfs_bg_type_to_raid_name(bargs->target));
return false;
}
/*
* Fill @buf with textual description of balance filter flags @bargs, up to
* @size_buf including the terminating null. The output may be trimmed if it
* does not fit into the provided buffer.
*/
static void describe_balance_args(struct btrfs_balance_args *bargs, char *buf,
u32 size_buf)
{
int ret;
u32 size_bp = size_buf;
char *bp = buf;
u64 flags = bargs->flags;
char tmp_buf[128] = {'\0'};
if (!flags)
return;
#define CHECK_APPEND_NOARG(a) \
do { \
ret = snprintf(bp, size_bp, (a)); \
if (ret < 0 || ret >= size_bp) \
goto out_overflow; \
size_bp -= ret; \
bp += ret; \
} while (0)
#define CHECK_APPEND_1ARG(a, v1) \
do { \
ret = snprintf(bp, size_bp, (a), (v1)); \
if (ret < 0 || ret >= size_bp) \
goto out_overflow; \
size_bp -= ret; \
bp += ret; \
} while (0)
#define CHECK_APPEND_2ARG(a, v1, v2) \
do { \
ret = snprintf(bp, size_bp, (a), (v1), (v2)); \
if (ret < 0 || ret >= size_bp) \
goto out_overflow; \
size_bp -= ret; \
bp += ret; \
} while (0)
if (flags & BTRFS_BALANCE_ARGS_CONVERT)
CHECK_APPEND_1ARG("convert=%s,",
btrfs_bg_type_to_raid_name(bargs->target));
if (flags & BTRFS_BALANCE_ARGS_SOFT)
CHECK_APPEND_NOARG("soft,");
if (flags & BTRFS_BALANCE_ARGS_PROFILES) {
btrfs_describe_block_groups(bargs->profiles, tmp_buf,
sizeof(tmp_buf));
CHECK_APPEND_1ARG("profiles=%s,", tmp_buf);
}
if (flags & BTRFS_BALANCE_ARGS_USAGE)
CHECK_APPEND_1ARG("usage=%llu,", bargs->usage);
if (flags & BTRFS_BALANCE_ARGS_USAGE_RANGE)
CHECK_APPEND_2ARG("usage=%u..%u,",
bargs->usage_min, bargs->usage_max);
if (flags & BTRFS_BALANCE_ARGS_DEVID)
CHECK_APPEND_1ARG("devid=%llu,", bargs->devid);
if (flags & BTRFS_BALANCE_ARGS_DRANGE)
CHECK_APPEND_2ARG("drange=%llu..%llu,",
bargs->pstart, bargs->pend);
if (flags & BTRFS_BALANCE_ARGS_VRANGE)
CHECK_APPEND_2ARG("vrange=%llu..%llu,",
bargs->vstart, bargs->vend);
if (flags & BTRFS_BALANCE_ARGS_LIMIT)
CHECK_APPEND_1ARG("limit=%llu,", bargs->limit);
if (flags & BTRFS_BALANCE_ARGS_LIMIT_RANGE)
CHECK_APPEND_2ARG("limit=%u..%u,",
bargs->limit_min, bargs->limit_max);
if (flags & BTRFS_BALANCE_ARGS_STRIPES_RANGE)
CHECK_APPEND_2ARG("stripes=%u..%u,",
bargs->stripes_min, bargs->stripes_max);
#undef CHECK_APPEND_2ARG
#undef CHECK_APPEND_1ARG
#undef CHECK_APPEND_NOARG
out_overflow:
if (size_bp < size_buf)
buf[size_buf - size_bp - 1] = '\0'; /* remove last , */
else
buf[0] = '\0';
}
static void describe_balance_start_or_resume(struct btrfs_fs_info *fs_info)
{
u32 size_buf = 1024;
char tmp_buf[192] = {'\0'};
char *buf;
char *bp;
u32 size_bp = size_buf;
int ret;
struct btrfs_balance_control *bctl = fs_info->balance_ctl;
buf = kzalloc(size_buf, GFP_KERNEL);
if (!buf)
return;
bp = buf;
#define CHECK_APPEND_1ARG(a, v1) \
do { \
ret = snprintf(bp, size_bp, (a), (v1)); \
if (ret < 0 || ret >= size_bp) \
goto out_overflow; \
size_bp -= ret; \
bp += ret; \
} while (0)
if (bctl->flags & BTRFS_BALANCE_FORCE)
CHECK_APPEND_1ARG("%s", "-f ");
if (bctl->flags & BTRFS_BALANCE_DATA) {
describe_balance_args(&bctl->data, tmp_buf, sizeof(tmp_buf));
CHECK_APPEND_1ARG("-d%s ", tmp_buf);
}
if (bctl->flags & BTRFS_BALANCE_METADATA) {
describe_balance_args(&bctl->meta, tmp_buf, sizeof(tmp_buf));
CHECK_APPEND_1ARG("-m%s ", tmp_buf);
}
if (bctl->flags & BTRFS_BALANCE_SYSTEM) {
describe_balance_args(&bctl->sys, tmp_buf, sizeof(tmp_buf));
CHECK_APPEND_1ARG("-s%s ", tmp_buf);
}
#undef CHECK_APPEND_1ARG
out_overflow:
if (size_bp < size_buf)
buf[size_buf - size_bp - 1] = '\0'; /* remove last " " */
btrfs_info(fs_info, "balance: %s %s",
(bctl->flags & BTRFS_BALANCE_RESUME) ?
"resume" : "start", buf);
kfree(buf);
}
/*
* Should be called with balance mutexe held
*/
int btrfs_balance(struct btrfs_fs_info *fs_info,
struct btrfs_balance_control *bctl,
struct btrfs_ioctl_balance_args *bargs)
{
u64 meta_target, data_target;
u64 allowed;
int mixed = 0;
int ret;
u64 num_devices;
unsigned seq;
bool reducing_redundancy;
int i;
if (btrfs_fs_closing(fs_info) ||
atomic_read(&fs_info->balance_pause_req) ||
btrfs_should_cancel_balance(fs_info)) {
ret = -EINVAL;
goto out;
}
allowed = btrfs_super_incompat_flags(fs_info->super_copy);
if (allowed & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
mixed = 1;
/*
* In case of mixed groups both data and meta should be picked,
* and identical options should be given for both of them.
*/
allowed = BTRFS_BALANCE_DATA | BTRFS_BALANCE_METADATA;
if (mixed && (bctl->flags & allowed)) {
if (!(bctl->flags & BTRFS_BALANCE_DATA) ||
!(bctl->flags & BTRFS_BALANCE_METADATA) ||
memcmp(&bctl->data, &bctl->meta, sizeof(bctl->data))) {
btrfs_err(fs_info,
"balance: mixed groups data and metadata options must be the same");
ret = -EINVAL;
goto out;
}
}
/*
* rw_devices will not change at the moment, device add/delete/replace
* are excluded by EXCL_OP
*/
num_devices = fs_info->fs_devices->rw_devices;
/*
* SINGLE profile on-disk has no profile bit, but in-memory we have a
* special bit for it, to make it easier to distinguish. Thus we need
* to set it manually, or balance would refuse the profile.
*/
allowed = BTRFS_AVAIL_ALLOC_BIT_SINGLE;
for (i = 0; i < ARRAY_SIZE(btrfs_raid_array); i++)
if (num_devices >= btrfs_raid_array[i].devs_min)
allowed |= btrfs_raid_array[i].bg_flag;
if (!validate_convert_profile(fs_info, &bctl->data, allowed, "data") ||
!validate_convert_profile(fs_info, &bctl->meta, allowed, "metadata") ||
!validate_convert_profile(fs_info, &bctl->sys, allowed, "system")) {
ret = -EINVAL;
goto out;
}
/*
* Allow to reduce metadata or system integrity only if force set for
* profiles with redundancy (copies, parity)
*/
allowed = 0;
for (i = 0; i < ARRAY_SIZE(btrfs_raid_array); i++) {
if (btrfs_raid_array[i].ncopies >= 2 ||
btrfs_raid_array[i].tolerated_failures >= 1)
allowed |= btrfs_raid_array[i].bg_flag;
}
do {
seq = read_seqbegin(&fs_info->profiles_lock);
if (((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
(fs_info->avail_system_alloc_bits & allowed) &&
!(bctl->sys.target & allowed)) ||
((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
(fs_info->avail_metadata_alloc_bits & allowed) &&
!(bctl->meta.target & allowed)))
reducing_redundancy = true;
else
reducing_redundancy = false;
/* if we're not converting, the target field is uninitialized */
meta_target = (bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) ?
bctl->meta.target : fs_info->avail_metadata_alloc_bits;
data_target = (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) ?
bctl->data.target : fs_info->avail_data_alloc_bits;
} while (read_seqretry(&fs_info->profiles_lock, seq));
if (reducing_redundancy) {
if (bctl->flags & BTRFS_BALANCE_FORCE) {
btrfs_info(fs_info,
"balance: force reducing metadata redundancy");
} else {
btrfs_err(fs_info,
"balance: reduces metadata redundancy, use --force if you want this");
ret = -EINVAL;
goto out;
}
}
if (btrfs_get_num_tolerated_disk_barrier_failures(meta_target) <
btrfs_get_num_tolerated_disk_barrier_failures(data_target)) {
btrfs_warn(fs_info,
"balance: metadata profile %s has lower redundancy than data profile %s",
btrfs_bg_type_to_raid_name(meta_target),
btrfs_bg_type_to_raid_name(data_target));
}
if (fs_info->send_in_progress) {
btrfs_warn_rl(fs_info,
"cannot run balance while send operations are in progress (%d in progress)",
fs_info->send_in_progress);
ret = -EAGAIN;
goto out;
}
ret = insert_balance_item(fs_info, bctl);
if (ret && ret != -EEXIST)
goto out;
if (!(bctl->flags & BTRFS_BALANCE_RESUME)) {
BUG_ON(ret == -EEXIST);
BUG_ON(fs_info->balance_ctl);
spin_lock(&fs_info->balance_lock);
fs_info->balance_ctl = bctl;
spin_unlock(&fs_info->balance_lock);
} else {
BUG_ON(ret != -EEXIST);
spin_lock(&fs_info->balance_lock);
update_balance_args(bctl);
spin_unlock(&fs_info->balance_lock);
}
ASSERT(!test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags));
set_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags);
describe_balance_start_or_resume(fs_info);
mutex_unlock(&fs_info->balance_mutex);
ret = __btrfs_balance(fs_info);
mutex_lock(&fs_info->balance_mutex);
if (ret == -ECANCELED && atomic_read(&fs_info->balance_pause_req))
btrfs_info(fs_info, "balance: paused");
else if (ret == -ECANCELED && atomic_read(&fs_info->balance_cancel_req))
btrfs_info(fs_info, "balance: canceled");
else
btrfs_info(fs_info, "balance: ended with status: %d", ret);
clear_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags);
if (bargs) {
memset(bargs, 0, sizeof(*bargs));
btrfs_update_ioctl_balance_args(fs_info, bargs);
}
if ((ret && ret != -ECANCELED && ret != -ENOSPC) ||
balance_need_close(fs_info)) {
reset_balance_state(fs_info);
clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
}
wake_up(&fs_info->balance_wait_q);
return ret;
out:
if (bctl->flags & BTRFS_BALANCE_RESUME)
reset_balance_state(fs_info);
else
kfree(bctl);
clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
return ret;
}
static int balance_kthread(void *data)
{
struct btrfs_fs_info *fs_info = data;
int ret = 0;
mutex_lock(&fs_info->balance_mutex);
if (fs_info->balance_ctl)
ret = btrfs_balance(fs_info, fs_info->balance_ctl, NULL);
mutex_unlock(&fs_info->balance_mutex);
return ret;
}
int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info)
{
struct task_struct *tsk;
mutex_lock(&fs_info->balance_mutex);
if (!fs_info->balance_ctl) {
mutex_unlock(&fs_info->balance_mutex);
return 0;
}
mutex_unlock(&fs_info->balance_mutex);
if (btrfs_test_opt(fs_info, SKIP_BALANCE)) {
btrfs_info(fs_info, "balance: resume skipped");
return 0;
}
/*
* A ro->rw remount sequence should continue with the paused balance
* regardless of who pauses it, system or the user as of now, so set
* the resume flag.
*/
spin_lock(&fs_info->balance_lock);
fs_info->balance_ctl->flags |= BTRFS_BALANCE_RESUME;
spin_unlock(&fs_info->balance_lock);
tsk = kthread_run(balance_kthread, fs_info, "btrfs-balance");
return PTR_ERR_OR_ZERO(tsk);
}
int btrfs_recover_balance(struct btrfs_fs_info *fs_info)
{
struct btrfs_balance_control *bctl;
struct btrfs_balance_item *item;
struct btrfs_disk_balance_args disk_bargs;
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_key key;
int ret;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
key.objectid = BTRFS_BALANCE_OBJECTID;
key.type = BTRFS_TEMPORARY_ITEM_KEY;
key.offset = 0;
ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
if (ret < 0)
goto out;
if (ret > 0) { /* ret = -ENOENT; */
ret = 0;
goto out;
}
bctl = kzalloc(sizeof(*bctl), GFP_NOFS);
if (!bctl) {
ret = -ENOMEM;
goto out;
}
leaf = path->nodes[0];
item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
bctl->flags = btrfs_balance_flags(leaf, item);
bctl->flags |= BTRFS_BALANCE_RESUME;
btrfs_balance_data(leaf, item, &disk_bargs);
btrfs_disk_balance_args_to_cpu(&bctl->data, &disk_bargs);
btrfs_balance_meta(leaf, item, &disk_bargs);
btrfs_disk_balance_args_to_cpu(&bctl->meta, &disk_bargs);
btrfs_balance_sys(leaf, item, &disk_bargs);
btrfs_disk_balance_args_to_cpu(&bctl->sys, &disk_bargs);
/*
* This should never happen, as the paused balance state is recovered
* during mount without any chance of other exclusive ops to collide.
*
* This gives the exclusive op status to balance and keeps in paused
* state until user intervention (cancel or umount). If the ownership
* cannot be assigned, show a message but do not fail. The balance
* is in a paused state and must have fs_info::balance_ctl properly
* set up.
*/
if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags))
btrfs_warn(fs_info,
"balance: cannot set exclusive op status, resume manually");
mutex_lock(&fs_info->balance_mutex);
BUG_ON(fs_info->balance_ctl);
spin_lock(&fs_info->balance_lock);
fs_info->balance_ctl = bctl;
spin_unlock(&fs_info->balance_lock);
mutex_unlock(&fs_info->balance_mutex);
out:
btrfs_free_path(path);
return ret;
}
int btrfs_pause_balance(struct btrfs_fs_info *fs_info)
{
int ret = 0;
mutex_lock(&fs_info->balance_mutex);
if (!fs_info->balance_ctl) {
mutex_unlock(&fs_info->balance_mutex);
return -ENOTCONN;
}
if (test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
atomic_inc(&fs_info->balance_pause_req);
mutex_unlock(&fs_info->balance_mutex);
wait_event(fs_info->balance_wait_q,
!test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags));
mutex_lock(&fs_info->balance_mutex);
/* we are good with balance_ctl ripped off from under us */
BUG_ON(test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags));
atomic_dec(&fs_info->balance_pause_req);
} else {
ret = -ENOTCONN;
}
mutex_unlock(&fs_info->balance_mutex);
return ret;
}
int btrfs_cancel_balance(struct btrfs_fs_info *fs_info)
{
mutex_lock(&fs_info->balance_mutex);
if (!fs_info->balance_ctl) {
mutex_unlock(&fs_info->balance_mutex);
return -ENOTCONN;
}
/*
* A paused balance with the item stored on disk can be resumed at
* mount time if the mount is read-write. Otherwise it's still paused
* and we must not allow cancelling as it deletes the item.
*/
if (sb_rdonly(fs_info->sb)) {
mutex_unlock(&fs_info->balance_mutex);
return -EROFS;
}
atomic_inc(&fs_info->balance_cancel_req);
/*
* if we are running just wait and return, balance item is
* deleted in btrfs_balance in this case
*/
if (test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
mutex_unlock(&fs_info->balance_mutex);
wait_event(fs_info->balance_wait_q,
!test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags));
mutex_lock(&fs_info->balance_mutex);
} else {
mutex_unlock(&fs_info->balance_mutex);
/*
* Lock released to allow other waiters to continue, we'll
* reexamine the status again.
*/
mutex_lock(&fs_info->balance_mutex);
if (fs_info->balance_ctl) {
reset_balance_state(fs_info);
clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
btrfs_info(fs_info, "balance: canceled");
}
}
BUG_ON(fs_info->balance_ctl ||
test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags));
atomic_dec(&fs_info->balance_cancel_req);
mutex_unlock(&fs_info->balance_mutex);
return 0;
}
int btrfs_uuid_scan_kthread(void *data)
{
struct btrfs_fs_info *fs_info = data;
struct btrfs_root *root = fs_info->tree_root;
struct btrfs_key key;
struct btrfs_path *path = NULL;
int ret = 0;
struct extent_buffer *eb;
int slot;
struct btrfs_root_item root_item;
u32 item_size;
struct btrfs_trans_handle *trans = NULL;
bool closing = false;
path = btrfs_alloc_path();
if (!path) {
ret = -ENOMEM;
goto out;
}
key.objectid = 0;
key.type = BTRFS_ROOT_ITEM_KEY;
key.offset = 0;
while (1) {
if (btrfs_fs_closing(fs_info)) {
closing = true;
break;
}
ret = btrfs_search_forward(root, &key, path,
BTRFS_OLDEST_GENERATION);
if (ret) {
if (ret > 0)
ret = 0;
break;
}
if (key.type != BTRFS_ROOT_ITEM_KEY ||
(key.objectid < BTRFS_FIRST_FREE_OBJECTID &&
key.objectid != BTRFS_FS_TREE_OBJECTID) ||
key.objectid > BTRFS_LAST_FREE_OBJECTID)
goto skip;
eb = path->nodes[0];
slot = path->slots[0];
item_size = btrfs_item_size_nr(eb, slot);
if (item_size < sizeof(root_item))
goto skip;
read_extent_buffer(eb, &root_item,
btrfs_item_ptr_offset(eb, slot),
(int)sizeof(root_item));
if (btrfs_root_refs(&root_item) == 0)
goto skip;
if (!btrfs_is_empty_uuid(root_item.uuid) ||
!btrfs_is_empty_uuid(root_item.received_uuid)) {
if (trans)
goto update_tree;
btrfs_release_path(path);
/*
* 1 - subvol uuid item
* 1 - received_subvol uuid item
*/
trans = btrfs_start_transaction(fs_info->uuid_root, 2);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
break;
}
continue;
} else {
goto skip;
}
update_tree:
if (!btrfs_is_empty_uuid(root_item.uuid)) {
ret = btrfs_uuid_tree_add(trans, root_item.uuid,
BTRFS_UUID_KEY_SUBVOL,
key.objectid);
if (ret < 0) {
btrfs_warn(fs_info, "uuid_tree_add failed %d",
ret);
break;
}
}
if (!btrfs_is_empty_uuid(root_item.received_uuid)) {
ret = btrfs_uuid_tree_add(trans,
root_item.received_uuid,
BTRFS_UUID_KEY_RECEIVED_SUBVOL,
key.objectid);
if (ret < 0) {
btrfs_warn(fs_info, "uuid_tree_add failed %d",
ret);
break;
}
}
skip:
if (trans) {
ret = btrfs_end_transaction(trans);
trans = NULL;
if (ret)
break;
}
btrfs_release_path(path);
if (key.offset < (u64)-1) {
key.offset++;
} else if (key.type < BTRFS_ROOT_ITEM_KEY) {
key.offset = 0;
key.type = BTRFS_ROOT_ITEM_KEY;
} else if (key.objectid < (u64)-1) {
key.offset = 0;
key.type = BTRFS_ROOT_ITEM_KEY;
key.objectid++;
} else {
break;
}
cond_resched();
}
out:
btrfs_free_path(path);
if (trans && !IS_ERR(trans))
btrfs_end_transaction(trans);
if (ret)
btrfs_warn(fs_info, "btrfs_uuid_scan_kthread failed %d", ret);
else if (!closing)
set_bit(BTRFS_FS_UPDATE_UUID_TREE_GEN, &fs_info->flags);
up(&fs_info->uuid_tree_rescan_sem);
return 0;
}
int btrfs_create_uuid_tree(struct btrfs_fs_info *fs_info)
{
struct btrfs_trans_handle *trans;
struct btrfs_root *tree_root = fs_info->tree_root;
struct btrfs_root *uuid_root;
struct task_struct *task;
int ret;
/*
* 1 - root node
* 1 - root item
*/
trans = btrfs_start_transaction(tree_root, 2);
if (IS_ERR(trans))
return PTR_ERR(trans);
uuid_root = btrfs_create_tree(trans, BTRFS_UUID_TREE_OBJECTID);
if (IS_ERR(uuid_root)) {
ret = PTR_ERR(uuid_root);
btrfs_abort_transaction(trans, ret);
btrfs_end_transaction(trans);
return ret;
}
fs_info->uuid_root = uuid_root;
ret = btrfs_commit_transaction(trans);
if (ret)
return ret;
down(&fs_info->uuid_tree_rescan_sem);
task = kthread_run(btrfs_uuid_scan_kthread, fs_info, "btrfs-uuid");
if (IS_ERR(task)) {
/* fs_info->update_uuid_tree_gen remains 0 in all error case */
btrfs_warn(fs_info, "failed to start uuid_scan task");
up(&fs_info->uuid_tree_rescan_sem);
return PTR_ERR(task);
}
return 0;
}
/*
* shrinking a device means finding all of the device extents past
* the new size, and then following the back refs to the chunks.
* The chunk relocation code actually frees the device extent
*/
int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
{
struct btrfs_fs_info *fs_info = device->fs_info;
struct btrfs_root *root = fs_info->dev_root;
struct btrfs_trans_handle *trans;
struct btrfs_dev_extent *dev_extent = NULL;
struct btrfs_path *path;
u64 length;
u64 chunk_offset;
int ret;
int slot;
int failed = 0;
bool retried = false;
struct extent_buffer *l;
struct btrfs_key key;
struct btrfs_super_block *super_copy = fs_info->super_copy;
u64 old_total = btrfs_super_total_bytes(super_copy);
u64 old_size = btrfs_device_get_total_bytes(device);
u64 diff;
u64 start;
new_size = round_down(new_size, fs_info->sectorsize);
start = new_size;
diff = round_down(old_size - new_size, fs_info->sectorsize);
if (test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state))
return -EINVAL;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->reada = READA_BACK;
trans = btrfs_start_transaction(root, 0);
if (IS_ERR(trans)) {
btrfs_free_path(path);
return PTR_ERR(trans);
}
mutex_lock(&fs_info->chunk_mutex);
btrfs_device_set_total_bytes(device, new_size);
if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) {
device->fs_devices->total_rw_bytes -= diff;
atomic64_sub(diff, &fs_info->free_chunk_space);
}
/*
* Once the device's size has been set to the new size, ensure all
* in-memory chunks are synced to disk so that the loop below sees them
* and relocates them accordingly.
*/
if (contains_pending_extent(device, &start, diff)) {
mutex_unlock(&fs_info->chunk_mutex);
ret = btrfs_commit_transaction(trans);
if (ret)
goto done;
} else {
mutex_unlock(&fs_info->chunk_mutex);
btrfs_end_transaction(trans);
}
again:
key.objectid = device->devid;
key.offset = (u64)-1;
key.type = BTRFS_DEV_EXTENT_KEY;
do {
mutex_lock(&fs_info->delete_unused_bgs_mutex);
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0) {
mutex_unlock(&fs_info->delete_unused_bgs_mutex);
goto done;
}
ret = btrfs_previous_item(root, path, 0, key.type);
if (ret)
mutex_unlock(&fs_info->delete_unused_bgs_mutex);
if (ret < 0)
goto done;
if (ret) {
ret = 0;
btrfs_release_path(path);
break;
}
l = path->nodes[0];
slot = path->slots[0];
btrfs_item_key_to_cpu(l, &key, path->slots[0]);
if (key.objectid != device->devid) {
mutex_unlock(&fs_info->delete_unused_bgs_mutex);
btrfs_release_path(path);
break;
}
dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
length = btrfs_dev_extent_length(l, dev_extent);
if (key.offset + length <= new_size) {
mutex_unlock(&fs_info->delete_unused_bgs_mutex);
btrfs_release_path(path);
break;
}
chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
btrfs_release_path(path);
/*
* We may be relocating the only data chunk we have,
* which could potentially end up with losing data's
* raid profile, so lets allocate an empty one in
* advance.
*/
ret = btrfs_may_alloc_data_chunk(fs_info, chunk_offset);
if (ret < 0) {
mutex_unlock(&fs_info->delete_unused_bgs_mutex);
goto done;
}
ret = btrfs_relocate_chunk(fs_info, chunk_offset);
mutex_unlock(&fs_info->delete_unused_bgs_mutex);
if (ret == -ENOSPC) {
failed++;
} else if (ret) {
if (ret == -ETXTBSY) {
btrfs_warn(fs_info,
"could not shrink block group %llu due to active swapfile",
chunk_offset);
}
goto done;
}
} while (key.offset-- > 0);
if (failed && !retried) {
failed = 0;
retried = true;
goto again;
} else if (failed && retried) {
ret = -ENOSPC;
goto done;
}
/* Shrinking succeeded, else we would be at "done". */
trans = btrfs_start_transaction(root, 0);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
goto done;
}
mutex_lock(&fs_info->chunk_mutex);
btrfs_device_set_disk_total_bytes(device, new_size);
if (list_empty(&device->post_commit_list))
list_add_tail(&device->post_commit_list,
&trans->transaction->dev_update_list);
WARN_ON(diff > old_total);
btrfs_set_super_total_bytes(super_copy,
round_down(old_total - diff, fs_info->sectorsize));
mutex_unlock(&fs_info->chunk_mutex);
/* Now btrfs_update_device() will change the on-disk size. */
ret = btrfs_update_device(trans, device);
if (ret < 0) {
btrfs_abort_transaction(trans, ret);
btrfs_end_transaction(trans);
} else {
ret = btrfs_commit_transaction(trans);
}
done:
btrfs_free_path(path);
if (ret) {
mutex_lock(&fs_info->chunk_mutex);
btrfs_device_set_total_bytes(device, old_size);
if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state))
device->fs_devices->total_rw_bytes += diff;
atomic64_add(diff, &fs_info->free_chunk_space);
mutex_unlock(&fs_info->chunk_mutex);
}
return ret;
}
static int btrfs_add_system_chunk(struct btrfs_fs_info *fs_info,
struct btrfs_key *key,
struct btrfs_chunk *chunk, int item_size)
{
struct btrfs_super_block *super_copy = fs_info->super_copy;
struct btrfs_disk_key disk_key;
u32 array_size;
u8 *ptr;
mutex_lock(&fs_info->chunk_mutex);
array_size = btrfs_super_sys_array_size(super_copy);
if (array_size + item_size + sizeof(disk_key)
> BTRFS_SYSTEM_CHUNK_ARRAY_SIZE) {
mutex_unlock(&fs_info->chunk_mutex);
return -EFBIG;
}
ptr = super_copy->sys_chunk_array + array_size;
btrfs_cpu_key_to_disk(&disk_key, key);
memcpy(ptr, &disk_key, sizeof(disk_key));
ptr += sizeof(disk_key);
memcpy(ptr, chunk, item_size);
item_size += sizeof(disk_key);
btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
mutex_unlock(&fs_info->chunk_mutex);
return 0;
}
/*
* sort the devices in descending order by max_avail, total_avail
*/
static int btrfs_cmp_device_info(const void *a, const void *b)
{
const struct btrfs_device_info *di_a = a;
const struct btrfs_device_info *di_b = b;
if (di_a->max_avail > di_b->max_avail)
return -1;
if (di_a->max_avail < di_b->max_avail)
return 1;
if (di_a->total_avail > di_b->total_avail)
return -1;
if (di_a->total_avail < di_b->total_avail)
return 1;
return 0;
}
static void check_raid56_incompat_flag(struct btrfs_fs_info *info, u64 type)
{
if (!(type & BTRFS_BLOCK_GROUP_RAID56_MASK))
return;
btrfs_set_fs_incompat(info, RAID56);
}
static void check_raid1c34_incompat_flag(struct btrfs_fs_info *info, u64 type)
{
if (!(type & (BTRFS_BLOCK_GROUP_RAID1C3 | BTRFS_BLOCK_GROUP_RAID1C4)))
return;
btrfs_set_fs_incompat(info, RAID1C34);
}
/*
* Structure used internally for __btrfs_alloc_chunk() function.
* Wraps needed parameters.
*/
struct alloc_chunk_ctl {
u64 start;
u64 type;
/* Total number of stripes to allocate */
int num_stripes;
/* sub_stripes info for map */
int sub_stripes;
/* Stripes per device */
int dev_stripes;
/* Maximum number of devices to use */
int devs_max;
/* Minimum number of devices to use */
int devs_min;
/* ndevs has to be a multiple of this */
int devs_increment;
/* Number of copies */
int ncopies;
/* Number of stripes worth of bytes to store parity information */
int nparity;
u64 max_stripe_size;
u64 max_chunk_size;
u64 dev_extent_min;
u64 stripe_size;
u64 chunk_size;
int ndevs;
};
static void init_alloc_chunk_ctl_policy_regular(
struct btrfs_fs_devices *fs_devices,
struct alloc_chunk_ctl *ctl)
{
u64 type = ctl->type;
if (type & BTRFS_BLOCK_GROUP_DATA) {
ctl->max_stripe_size = SZ_1G;
ctl->max_chunk_size = BTRFS_MAX_DATA_CHUNK_SIZE;
} else if (type & BTRFS_BLOCK_GROUP_METADATA) {
/* For larger filesystems, use larger metadata chunks */
if (fs_devices->total_rw_bytes > 50ULL * SZ_1G)
ctl->max_stripe_size = SZ_1G;
else
ctl->max_stripe_size = SZ_256M;
ctl->max_chunk_size = ctl->max_stripe_size;
} else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
ctl->max_stripe_size = SZ_32M;
ctl->max_chunk_size = 2 * ctl->max_stripe_size;
ctl->devs_max = min_t(int, ctl->devs_max,
BTRFS_MAX_DEVS_SYS_CHUNK);
} else {
BUG();
}
/* We don't want a chunk larger than 10% of writable space */
ctl->max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1),
ctl->max_chunk_size);
ctl->dev_extent_min = BTRFS_STRIPE_LEN * ctl->dev_stripes;
}
static void init_alloc_chunk_ctl(struct btrfs_fs_devices *fs_devices,
struct alloc_chunk_ctl *ctl)
{
int index = btrfs_bg_flags_to_raid_index(ctl->type);
ctl->sub_stripes = btrfs_raid_array[index].sub_stripes;
ctl->dev_stripes = btrfs_raid_array[index].dev_stripes;
ctl->devs_max = btrfs_raid_array[index].devs_max;
if (!ctl->devs_max)
ctl->devs_max = BTRFS_MAX_DEVS(fs_devices->fs_info);
ctl->devs_min = btrfs_raid_array[index].devs_min;
ctl->devs_increment = btrfs_raid_array[index].devs_increment;
ctl->ncopies = btrfs_raid_array[index].ncopies;
ctl->nparity = btrfs_raid_array[index].nparity;
ctl->ndevs = 0;
switch (fs_devices->chunk_alloc_policy) {
case BTRFS_CHUNK_ALLOC_REGULAR:
init_alloc_chunk_ctl_policy_regular(fs_devices, ctl);
break;
default:
BUG();
}
}
static int gather_device_info(struct btrfs_fs_devices *fs_devices,
struct alloc_chunk_ctl *ctl,
struct btrfs_device_info *devices_info)
{
struct btrfs_fs_info *info = fs_devices->fs_info;
struct btrfs_device *device;
u64 total_avail;
u64 dev_extent_want = ctl->max_stripe_size * ctl->dev_stripes;
int ret;
int ndevs = 0;
u64 max_avail;
u64 dev_offset;
/*
* in the first pass through the devices list, we gather information
* about the available holes on each device.
*/
list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) {
if (!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) {
WARN(1, KERN_ERR
"BTRFS: read-only device in alloc_list\n");
continue;
}
if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA,
&device->dev_state) ||
test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state))
continue;
if (device->total_bytes > device->bytes_used)
total_avail = device->total_bytes - device->bytes_used;
else
total_avail = 0;
/* If there is no space on this device, skip it. */
if (total_avail < ctl->dev_extent_min)
continue;
ret = find_free_dev_extent(device, dev_extent_want, &dev_offset,
&max_avail);
if (ret && ret != -ENOSPC)
return ret;
if (ret == 0)
max_avail = dev_extent_want;
if (max_avail < ctl->dev_extent_min) {
if (btrfs_test_opt(info, ENOSPC_DEBUG))
btrfs_debug(info,
"%s: devid %llu has no free space, have=%llu want=%llu",
__func__, device->devid, max_avail,
ctl->dev_extent_min);
continue;
}
if (ndevs == fs_devices->rw_devices) {
WARN(1, "%s: found more than %llu devices\n",
__func__, fs_devices->rw_devices);
break;
}
devices_info[ndevs].dev_offset = dev_offset;
devices_info[ndevs].max_avail = max_avail;
devices_info[ndevs].total_avail = total_avail;
devices_info[ndevs].dev = device;
++ndevs;
}
ctl->ndevs = ndevs;
/*
* now sort the devices by hole size / available space
*/
sort(devices_info, ndevs, sizeof(struct btrfs_device_info),
btrfs_cmp_device_info, NULL);
return 0;
}
static int decide_stripe_size_regular(struct alloc_chunk_ctl *ctl,
struct btrfs_device_info *devices_info)
{
/* Number of stripes that count for block group size */
int data_stripes;
/*
* The primary goal is to maximize the number of stripes, so use as
* many devices as possible, even if the stripes are not maximum sized.
*
* The DUP profile stores more than one stripe per device, the
* max_avail is the total size so we have to adjust.
*/
ctl->stripe_size = div_u64(devices_info[ctl->ndevs - 1].max_avail,
ctl->dev_stripes);
ctl->num_stripes = ctl->ndevs * ctl->dev_stripes;
/* This will have to be fixed for RAID1 and RAID10 over more drives */
data_stripes = (ctl->num_stripes - ctl->nparity) / ctl->ncopies;
/*
* Use the number of data stripes to figure out how big this chunk is
* really going to be in terms of logical address space, and compare
* that answer with the max chunk size. If it's higher, we try to
* reduce stripe_size.
*/
if (ctl->stripe_size * data_stripes > ctl->max_chunk_size) {
/*
* Reduce stripe_size, round it up to a 16MB boundary again and
* then use it, unless it ends up being even bigger than the
* previous value we had already.
*/
ctl->stripe_size = min(round_up(div_u64(ctl->max_chunk_size,
data_stripes), SZ_16M),
ctl->stripe_size);
}
/* Align to BTRFS_STRIPE_LEN */
ctl->stripe_size = round_down(ctl->stripe_size, BTRFS_STRIPE_LEN);
ctl->chunk_size = ctl->stripe_size * data_stripes;
return 0;
}
static int decide_stripe_size(struct btrfs_fs_devices *fs_devices,
struct alloc_chunk_ctl *ctl,
struct btrfs_device_info *devices_info)
{
struct btrfs_fs_info *info = fs_devices->fs_info;
/*
* Round down to number of usable stripes, devs_increment can be any
* number so we can't use round_down() that requires power of 2, while
* rounddown is safe.
*/
ctl->ndevs = rounddown(ctl->ndevs, ctl->devs_increment);
if (ctl->ndevs < ctl->devs_min) {
if (btrfs_test_opt(info, ENOSPC_DEBUG)) {
btrfs_debug(info,
"%s: not enough devices with free space: have=%d minimum required=%d",
__func__, ctl->ndevs, ctl->devs_min);
}
return -ENOSPC;
}
ctl->ndevs = min(ctl->ndevs, ctl->devs_max);
switch (fs_devices->chunk_alloc_policy) {
case BTRFS_CHUNK_ALLOC_REGULAR:
return decide_stripe_size_regular(ctl, devices_info);
default:
BUG();
}
}
static int create_chunk(struct btrfs_trans_handle *trans,
struct alloc_chunk_ctl *ctl,
struct btrfs_device_info *devices_info)
{
struct btrfs_fs_info *info = trans->fs_info;
struct map_lookup *map = NULL;
struct extent_map_tree *em_tree;
struct extent_map *em;
u64 start = ctl->start;
u64 type = ctl->type;
int ret;
int i;
int j;
map = kmalloc(map_lookup_size(ctl->num_stripes), GFP_NOFS);
if (!map)
return -ENOMEM;
map->num_stripes = ctl->num_stripes;
for (i = 0; i < ctl->ndevs; ++i) {
for (j = 0; j < ctl->dev_stripes; ++j) {
int s = i * ctl->dev_stripes + j;
map->stripes[s].dev = devices_info[i].dev;
map->stripes[s].physical = devices_info[i].dev_offset +
j * ctl->stripe_size;
}
}
map->stripe_len = BTRFS_STRIPE_LEN;
map->io_align = BTRFS_STRIPE_LEN;
map->io_width = BTRFS_STRIPE_LEN;
map->type = type;
map->sub_stripes = ctl->sub_stripes;
trace_btrfs_chunk_alloc(info, map, start, ctl->chunk_size);
em = alloc_extent_map();
if (!em) {
kfree(map);
return -ENOMEM;
}
set_bit(EXTENT_FLAG_FS_MAPPING, &em->flags);
em->map_lookup = map;
em->start = start;
em->len = ctl->chunk_size;
em->block_start = 0;
em->block_len = em->len;
em->orig_block_len = ctl->stripe_size;
em_tree = &info->mapping_tree;
write_lock(&em_tree->lock);
ret = add_extent_mapping(em_tree, em, 0);
if (ret) {
write_unlock(&em_tree->lock);
free_extent_map(em);
return ret;
}
write_unlock(&em_tree->lock);
ret = btrfs_make_block_group(trans, 0, type, start, ctl->chunk_size);
if (ret)
goto error_del_extent;
for (i = 0; i < map->num_stripes; i++) {
struct btrfs_device *dev = map->stripes[i].dev;
btrfs_device_set_bytes_used(dev,
dev->bytes_used + ctl->stripe_size);
if (list_empty(&dev->post_commit_list))
list_add_tail(&dev->post_commit_list,
&trans->transaction->dev_update_list);
}
atomic64_sub(ctl->stripe_size * map->num_stripes,
&info->free_chunk_space);
free_extent_map(em);
check_raid56_incompat_flag(info, type);
check_raid1c34_incompat_flag(info, type);
return 0;
error_del_extent:
write_lock(&em_tree->lock);
remove_extent_mapping(em_tree, em);
write_unlock(&em_tree->lock);
/* One for our allocation */
free_extent_map(em);
/* One for the tree reference */
free_extent_map(em);
return ret;
}
int btrfs_alloc_chunk(struct btrfs_trans_handle *trans, u64 type)
{
struct btrfs_fs_info *info = trans->fs_info;
struct btrfs_fs_devices *fs_devices = info->fs_devices;
struct btrfs_device_info *devices_info = NULL;
struct alloc_chunk_ctl ctl;
int ret;
lockdep_assert_held(&info->chunk_mutex);
if (!alloc_profile_is_valid(type, 0)) {
ASSERT(0);
return -EINVAL;
}
if (list_empty(&fs_devices->alloc_list)) {
if (btrfs_test_opt(info, ENOSPC_DEBUG))
btrfs_debug(info, "%s: no writable device", __func__);
return -ENOSPC;
}
if (!(type & BTRFS_BLOCK_GROUP_TYPE_MASK)) {
btrfs_err(info, "invalid chunk type 0x%llx requested", type);
ASSERT(0);
return -EINVAL;
}
ctl.start = find_next_chunk(info);
ctl.type = type;
init_alloc_chunk_ctl(fs_devices, &ctl);
devices_info = kcalloc(fs_devices->rw_devices, sizeof(*devices_info),
GFP_NOFS);
if (!devices_info)
return -ENOMEM;
ret = gather_device_info(fs_devices, &ctl, devices_info);
if (ret < 0)
goto out;
ret = decide_stripe_size(fs_devices, &ctl, devices_info);
if (ret < 0)
goto out;
ret = create_chunk(trans, &ctl, devices_info);
out:
kfree(devices_info);
return ret;
}
/*
* Chunk allocation falls into two parts. The first part does work
* that makes the new allocated chunk usable, but does not do any operation
* that modifies the chunk tree. The second part does the work that
* requires modifying the chunk tree. This division is important for the
* bootstrap process of adding storage to a seed btrfs.
*/
int btrfs_finish_chunk_alloc(struct btrfs_trans_handle *trans,
u64 chunk_offset, u64 chunk_size)
{
struct btrfs_fs_info *fs_info = trans->fs_info;
struct btrfs_root *extent_root = fs_info->extent_root;
struct btrfs_root *chunk_root = fs_info->chunk_root;
struct btrfs_key key;
struct btrfs_device *device;
struct btrfs_chunk *chunk;
struct btrfs_stripe *stripe;
struct extent_map *em;
struct map_lookup *map;
size_t item_size;
u64 dev_offset;
u64 stripe_size;
int i = 0;
int ret = 0;
em = btrfs_get_chunk_map(fs_info, chunk_offset, chunk_size);
if (IS_ERR(em))
return PTR_ERR(em);
map = em->map_lookup;
item_size = btrfs_chunk_item_size(map->num_stripes);
stripe_size = em->orig_block_len;
chunk = kzalloc(item_size, GFP_NOFS);
if (!chunk) {
ret = -ENOMEM;
goto out;
}
/*
* Take the device list mutex to prevent races with the final phase of
* a device replace operation that replaces the device object associated
* with the map's stripes, because the device object's id can change
* at any time during that final phase of the device replace operation
* (dev-replace.c:btrfs_dev_replace_finishing()).
*/
mutex_lock(&fs_info->fs_devices->device_list_mutex);
for (i = 0; i < map->num_stripes; i++) {
device = map->stripes[i].dev;
dev_offset = map->stripes[i].physical;
ret = btrfs_update_device(trans, device);
if (ret)
break;
ret = btrfs_alloc_dev_extent(trans, device, chunk_offset,
dev_offset, stripe_size);
if (ret)
break;
}
if (ret) {
mutex_unlock(&fs_info->fs_devices->device_list_mutex);
goto out;
}
stripe = &chunk->stripe;
for (i = 0; i < map->num_stripes; i++) {
device = map->stripes[i].dev;
dev_offset = map->stripes[i].physical;
btrfs_set_stack_stripe_devid(stripe, device->devid);
btrfs_set_stack_stripe_offset(stripe, dev_offset);
memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
stripe++;
}
mutex_unlock(&fs_info->fs_devices->device_list_mutex);
btrfs_set_stack_chunk_length(chunk, chunk_size);
btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
btrfs_set_stack_chunk_stripe_len(chunk, map->stripe_len);
btrfs_set_stack_chunk_type(chunk, map->type);
btrfs_set_stack_chunk_num_stripes(chunk, map->num_stripes);
btrfs_set_stack_chunk_io_align(chunk, map->stripe_len);
btrfs_set_stack_chunk_io_width(chunk, map->stripe_len);
btrfs_set_stack_chunk_sector_size(chunk, fs_info->sectorsize);
btrfs_set_stack_chunk_sub_stripes(chunk, map->sub_stripes);
key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
key.type = BTRFS_CHUNK_ITEM_KEY;
key.offset = chunk_offset;
ret = btrfs_insert_item(trans, chunk_root, &key, chunk, item_size);
if (ret == 0 && map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
/*
* TODO: Cleanup of inserted chunk root in case of
* failure.
*/
ret = btrfs_add_system_chunk(fs_info, &key, chunk, item_size);
}
out:
kfree(chunk);
free_extent_map(em);
return ret;
}
static noinline int init_first_rw_device(struct btrfs_trans_handle *trans)
{
struct btrfs_fs_info *fs_info = trans->fs_info;
u64 alloc_profile;
int ret;
alloc_profile = btrfs_metadata_alloc_profile(fs_info);
ret = btrfs_alloc_chunk(trans, alloc_profile);
if (ret)
return ret;
alloc_profile = btrfs_system_alloc_profile(fs_info);
ret = btrfs_alloc_chunk(trans, alloc_profile);
return ret;
}
static inline int btrfs_chunk_max_errors(struct map_lookup *map)
{
const int index = btrfs_bg_flags_to_raid_index(map->type);
return btrfs_raid_array[index].tolerated_failures;
}
int btrfs_chunk_readonly(struct btrfs_fs_info *fs_info, u64 chunk_offset)
{
struct extent_map *em;
struct map_lookup *map;
int readonly = 0;
int miss_ndevs = 0;
int i;
em = btrfs_get_chunk_map(fs_info, chunk_offset, 1);
if (IS_ERR(em))
return 1;
map = em->map_lookup;
for (i = 0; i < map->num_stripes; i++) {
if (test_bit(BTRFS_DEV_STATE_MISSING,
&map->stripes[i].dev->dev_state)) {
miss_ndevs++;
continue;
}
if (!test_bit(BTRFS_DEV_STATE_WRITEABLE,
&map->stripes[i].dev->dev_state)) {
readonly = 1;
goto end;
}
}
/*
* If the number of missing devices is larger than max errors,
* we can not write the data into that chunk successfully, so
* set it readonly.
*/
if (miss_ndevs > btrfs_chunk_max_errors(map))
readonly = 1;
end:
free_extent_map(em);
return readonly;
}
void btrfs_mapping_tree_free(struct extent_map_tree *tree)
{
struct extent_map *em;
while (1) {
write_lock(&tree->lock);
em = lookup_extent_mapping(tree, 0, (u64)-1);
if (em)
remove_extent_mapping(tree, em);
write_unlock(&tree->lock);
if (!em)
break;
/* once for us */
free_extent_map(em);
/* once for the tree */
free_extent_map(em);
}
}
int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len)
{
struct extent_map *em;
struct map_lookup *map;
int ret;
em = btrfs_get_chunk_map(fs_info, logical, len);
if (IS_ERR(em))
/*
* We could return errors for these cases, but that could get
* ugly and we'd probably do the same thing which is just not do
* anything else and exit, so return 1 so the callers don't try
* to use other copies.
*/
return 1;
map = em->map_lookup;
if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1_MASK))
ret = map->num_stripes;
else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
ret = map->sub_stripes;
else if (map->type & BTRFS_BLOCK_GROUP_RAID5)
ret = 2;
else if (map->type & BTRFS_BLOCK_GROUP_RAID6)
/*
* There could be two corrupted data stripes, we need
* to loop retry in order to rebuild the correct data.
*
* Fail a stripe at a time on every retry except the
* stripe under reconstruction.
*/
ret = map->num_stripes;
else
ret = 1;
free_extent_map(em);
down_read(&fs_info->dev_replace.rwsem);
if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace) &&
fs_info->dev_replace.tgtdev)
ret++;
up_read(&fs_info->dev_replace.rwsem);
return ret;
}
unsigned long btrfs_full_stripe_len(struct btrfs_fs_info *fs_info,
u64 logical)
{
struct extent_map *em;
struct map_lookup *map;
unsigned long len = fs_info->sectorsize;
em = btrfs_get_chunk_map(fs_info, logical, len);
if (!WARN_ON(IS_ERR(em))) {
map = em->map_lookup;
if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK)
len = map->stripe_len * nr_data_stripes(map);
free_extent_map(em);
}
return len;
}
int btrfs_is_parity_mirror(struct btrfs_fs_info *fs_info, u64 logical, u64 len)
{
struct extent_map *em;
struct map_lookup *map;
int ret = 0;
em = btrfs_get_chunk_map(fs_info, logical, len);
if(!WARN_ON(IS_ERR(em))) {
map = em->map_lookup;
if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK)
ret = 1;
free_extent_map(em);
}
return ret;
}
static int find_live_mirror(struct btrfs_fs_info *fs_info,
struct map_lookup *map, int first,
int dev_replace_is_ongoing)
{
int i;
int num_stripes;
int preferred_mirror;
int tolerance;
struct btrfs_device *srcdev;
ASSERT((map->type &
(BTRFS_BLOCK_GROUP_RAID1_MASK | BTRFS_BLOCK_GROUP_RAID10)));
if (map->type & BTRFS_BLOCK_GROUP_RAID10)
num_stripes = map->sub_stripes;
else
num_stripes = map->num_stripes;
preferred_mirror = first + current->pid % num_stripes;
if (dev_replace_is_ongoing &&
fs_info->dev_replace.cont_reading_from_srcdev_mode ==
BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_AVOID)
srcdev = fs_info->dev_replace.srcdev;
else
srcdev = NULL;
/*
* try to avoid the drive that is the source drive for a
* dev-replace procedure, only choose it if no other non-missing
* mirror is available
*/
for (tolerance = 0; tolerance < 2; tolerance++) {
if (map->stripes[preferred_mirror].dev->bdev &&
(tolerance || map->stripes[preferred_mirror].dev != srcdev))
return preferred_mirror;
for (i = first; i < first + num_stripes; i++) {
if (map->stripes[i].dev->bdev &&
(tolerance || map->stripes[i].dev != srcdev))
return i;
}
}
/* we couldn't find one that doesn't fail. Just return something
* and the io error handling code will clean up eventually
*/
return preferred_mirror;
}
/* Bubble-sort the stripe set to put the parity/syndrome stripes last */
static void sort_parity_stripes(struct btrfs_bio *bbio, int num_stripes)
{
int i;
int again = 1;
while (again) {
again = 0;
for (i = 0; i < num_stripes - 1; i++) {
/* Swap if parity is on a smaller index */
if (bbio->raid_map[i] > bbio->raid_map[i + 1]) {
swap(bbio->stripes[i], bbio->stripes[i + 1]);
swap(bbio->raid_map[i], bbio->raid_map[i + 1]);
again = 1;
}
}
}
}
static struct btrfs_bio *alloc_btrfs_bio(int total_stripes, int real_stripes)
{
struct btrfs_bio *bbio = kzalloc(
/* the size of the btrfs_bio */
sizeof(struct btrfs_bio) +
/* plus the variable array for the stripes */
sizeof(struct btrfs_bio_stripe) * (total_stripes) +
/* plus the variable array for the tgt dev */
sizeof(int) * (real_stripes) +
/*
* plus the raid_map, which includes both the tgt dev
* and the stripes
*/
sizeof(u64) * (total_stripes),
GFP_NOFS|__GFP_NOFAIL);
atomic_set(&bbio->error, 0);
refcount_set(&bbio->refs, 1);
return bbio;
}
void btrfs_get_bbio(struct btrfs_bio *bbio)
{
WARN_ON(!refcount_read(&bbio->refs));
refcount_inc(&bbio->refs);
}
void btrfs_put_bbio(struct btrfs_bio *bbio)
{
if (!bbio)
return;
if (refcount_dec_and_test(&bbio->refs))
kfree(bbio);
}
/* can REQ_OP_DISCARD be sent with other REQ like REQ_OP_WRITE? */
/*
* Please note that, discard won't be sent to target device of device
* replace.
*/
static int __btrfs_map_block_for_discard(struct btrfs_fs_info *fs_info,
u64 logical, u64 *length_ret,
struct btrfs_bio **bbio_ret)
{
struct extent_map *em;
struct map_lookup *map;
struct btrfs_bio *bbio;
u64 length = *length_ret;
u64 offset;
u64 stripe_nr;
u64 stripe_nr_end;
u64 stripe_end_offset;
u64 stripe_cnt;
u64 stripe_len;
u64 stripe_offset;
u64 num_stripes;
u32 stripe_index;
u32 factor = 0;
u32 sub_stripes = 0;
u64 stripes_per_dev = 0;
u32 remaining_stripes = 0;
u32 last_stripe = 0;
int ret = 0;
int i;
/* discard always return a bbio */
ASSERT(bbio_ret);
em = btrfs_get_chunk_map(fs_info, logical, length);
if (IS_ERR(em))
return PTR_ERR(em);
map = em->map_lookup;
/* we don't discard raid56 yet */
if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
ret = -EOPNOTSUPP;
goto out;
}
offset = logical - em->start;
length = min_t(u64, em->start + em->len - logical, length);
*length_ret = length;
stripe_len = map->stripe_len;
/*
* stripe_nr counts the total number of stripes we have to stride
* to get to this block
*/
stripe_nr = div64_u64(offset, stripe_len);
/* stripe_offset is the offset of this block in its stripe */
stripe_offset = offset - stripe_nr * stripe_len;
stripe_nr_end = round_up(offset + length, map->stripe_len);
stripe_nr_end = div64_u64(stripe_nr_end, map->stripe_len);
stripe_cnt = stripe_nr_end - stripe_nr;
stripe_end_offset = stripe_nr_end * map->stripe_len -
(offset + length);
/*
* after this, stripe_nr is the number of stripes on this
* device we have to walk to find the data, and stripe_index is
* the number of our device in the stripe array
*/
num_stripes = 1;
stripe_index = 0;
if (map->type & (BTRFS_BLOCK_GROUP_RAID0 |
BTRFS_BLOCK_GROUP_RAID10)) {
if (map->type & BTRFS_BLOCK_GROUP_RAID0)
sub_stripes = 1;
else
sub_stripes = map->sub_stripes;
factor = map->num_stripes / sub_stripes;
num_stripes = min_t(u64, map->num_stripes,
sub_stripes * stripe_cnt);
stripe_nr = div_u64_rem(stripe_nr, factor, &stripe_index);
stripe_index *= sub_stripes;
stripes_per_dev = div_u64_rem(stripe_cnt, factor,
&remaining_stripes);
div_u64_rem(stripe_nr_end - 1, factor, &last_stripe);
last_stripe *= sub_stripes;
} else if (map->type & (BTRFS_BLOCK_GROUP_RAID1_MASK |
BTRFS_BLOCK_GROUP_DUP)) {
num_stripes = map->num_stripes;
} else {
stripe_nr = div_u64_rem(stripe_nr, map->num_stripes,
&stripe_index);
}
bbio = alloc_btrfs_bio(num_stripes, 0);
if (!bbio) {
ret = -ENOMEM;
goto out;
}
for (i = 0; i < num_stripes; i++) {
bbio->stripes[i].physical =
map->stripes[stripe_index].physical +
stripe_offset + stripe_nr * map->stripe_len;
bbio->stripes[i].dev = map->stripes[stripe_index].dev;
if (map->type & (BTRFS_BLOCK_GROUP_RAID0 |
BTRFS_BLOCK_GROUP_RAID10)) {
bbio->stripes[i].length = stripes_per_dev *
map->stripe_len;
if (i / sub_stripes < remaining_stripes)
bbio->stripes[i].length +=
map->stripe_len;
/*
* Special for the first stripe and
* the last stripe:
*
* |-------|...|-------|
* |----------|
* off end_off
*/
if (i < sub_stripes)
bbio->stripes[i].length -=
stripe_offset;
if (stripe_index >= last_stripe &&
stripe_index <= (last_stripe +
sub_stripes - 1))
bbio->stripes[i].length -=
stripe_end_offset;
if (i == sub_stripes - 1)
stripe_offset = 0;
} else {
bbio->stripes[i].length = length;
}
stripe_index++;
if (stripe_index == map->num_stripes) {
stripe_index = 0;
stripe_nr++;
}
}
*bbio_ret = bbio;
bbio->map_type = map->type;
bbio->num_stripes = num_stripes;
out:
free_extent_map(em);
return ret;
}
/*
* In dev-replace case, for repair case (that's the only case where the mirror
* is selected explicitly when calling btrfs_map_block), blocks left of the
* left cursor can also be read from the target drive.
*
* For REQ_GET_READ_MIRRORS, the target drive is added as the last one to the
* array of stripes.
* For READ, it also needs to be supported using the same mirror number.
*
* If the requested block is not left of the left cursor, EIO is returned. This
* can happen because btrfs_num_copies() returns one more in the dev-replace
* case.
*/
static int get_extra_mirror_from_replace(struct btrfs_fs_info *fs_info,
u64 logical, u64 length,
u64 srcdev_devid, int *mirror_num,
u64 *physical)
{
struct btrfs_bio *bbio = NULL;
int num_stripes;
int index_srcdev = 0;
int found = 0;
u64 physical_of_found = 0;
int i;
int ret = 0;
ret = __btrfs_map_block(fs_info, BTRFS_MAP_GET_READ_MIRRORS,
logical, &length, &bbio, 0, 0);
if (ret) {
ASSERT(bbio == NULL);
return ret;
}
num_stripes = bbio->num_stripes;
if (*mirror_num > num_stripes) {
/*
* BTRFS_MAP_GET_READ_MIRRORS does not contain this mirror,
* that means that the requested area is not left of the left
* cursor
*/
btrfs_put_bbio(bbio);
return -EIO;
}
/*
* process the rest of the function using the mirror_num of the source
* drive. Therefore look it up first. At the end, patch the device
* pointer to the one of the target drive.
*/
for (i = 0; i < num_stripes; i++) {
if (bbio->stripes[i].dev->devid != srcdev_devid)
continue;
/*
* In case of DUP, in order to keep it simple, only add the
* mirror with the lowest physical address
*/
if (found &&
physical_of_found <= bbio->stripes[i].physical)
continue;
index_srcdev = i;
found = 1;
physical_of_found = bbio->stripes[i].physical;
}
btrfs_put_bbio(bbio);
ASSERT(found);
if (!found)
return -EIO;
*mirror_num = index_srcdev + 1;
*physical = physical_of_found;
return ret;
}
static void handle_ops_on_dev_replace(enum btrfs_map_op op,
struct btrfs_bio **bbio_ret,
struct btrfs_dev_replace *dev_replace,
int *num_stripes_ret, int *max_errors_ret)
{
struct btrfs_bio *bbio = *bbio_ret;
u64 srcdev_devid = dev_replace->srcdev->devid;
int tgtdev_indexes = 0;
int num_stripes = *num_stripes_ret;
int max_errors = *max_errors_ret;
int i;
if (op == BTRFS_MAP_WRITE) {
int index_where_to_add;
/*
* duplicate the write operations while the dev replace
* procedure is running. Since the copying of the old disk to
* the new disk takes place at run time while the filesystem is
* mounted writable, the regular write operations to the old
* disk have to be duplicated to go to the new disk as well.
*
* Note that device->missing is handled by the caller, and that
* the write to the old disk is already set up in the stripes
* array.
*/
index_where_to_add = num_stripes;
for (i = 0; i < num_stripes; i++) {
if (bbio->stripes[i].dev->devid == srcdev_devid) {
/* write to new disk, too */
struct btrfs_bio_stripe *new =
bbio->stripes + index_where_to_add;
struct btrfs_bio_stripe *old =
bbio->stripes + i;
new->physical = old->physical;
new->length = old->length;
new->dev = dev_replace->tgtdev;
bbio->tgtdev_map[i] = index_where_to_add;
index_where_to_add++;
max_errors++;
tgtdev_indexes++;
}
}
num_stripes = index_where_to_add;
} else if (op == BTRFS_MAP_GET_READ_MIRRORS) {
int index_srcdev = 0;
int found = 0;
u64 physical_of_found = 0;
/*
* During the dev-replace procedure, the target drive can also
* be used to read data in case it is needed to repair a corrupt
* block elsewhere. This is possible if the requested area is
* left of the left cursor. In this area, the target drive is a
* full copy of the source drive.
*/
for (i = 0; i < num_stripes; i++) {
if (bbio->stripes[i].dev->devid == srcdev_devid) {
/*
* In case of DUP, in order to keep it simple,
* only add the mirror with the lowest physical
* address
*/
if (found &&
physical_of_found <=
bbio->stripes[i].physical)
continue;
index_srcdev = i;
found = 1;
physical_of_found = bbio->stripes[i].physical;
}
}
if (found) {
struct btrfs_bio_stripe *tgtdev_stripe =
bbio->stripes + num_stripes;
tgtdev_stripe->physical = physical_of_found;
tgtdev_stripe->length =
bbio->stripes[index_srcdev].length;
tgtdev_stripe->dev = dev_replace->tgtdev;
bbio->tgtdev_map[index_srcdev] = num_stripes;
tgtdev_indexes++;
num_stripes++;
}
}
*num_stripes_ret = num_stripes;
*max_errors_ret = max_errors;
bbio->num_tgtdevs = tgtdev_indexes;
*bbio_ret = bbio;
}
static bool need_full_stripe(enum btrfs_map_op op)
{
return (op == BTRFS_MAP_WRITE || op == BTRFS_MAP_GET_READ_MIRRORS);
}
/*
* btrfs_get_io_geometry - calculates the geomery of a particular (address, len)
* tuple. This information is used to calculate how big a
* particular bio can get before it straddles a stripe.
*
* @fs_info - the filesystem
* @logical - address that we want to figure out the geometry of
* @len - the length of IO we are going to perform, starting at @logical
* @op - type of operation - write or read
* @io_geom - pointer used to return values
*
* Returns < 0 in case a chunk for the given logical address cannot be found,
* usually shouldn't happen unless @logical is corrupted, 0 otherwise.
*/
int btrfs_get_io_geometry(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
u64 logical, u64 len, struct btrfs_io_geometry *io_geom)
{
struct extent_map *em;
struct map_lookup *map;
u64 offset;
u64 stripe_offset;
u64 stripe_nr;
u64 stripe_len;
u64 raid56_full_stripe_start = (u64)-1;
int data_stripes;
int ret = 0;
ASSERT(op != BTRFS_MAP_DISCARD);
em = btrfs_get_chunk_map(fs_info, logical, len);
if (IS_ERR(em))
return PTR_ERR(em);
map = em->map_lookup;
/* Offset of this logical address in the chunk */
offset = logical - em->start;
/* Len of a stripe in a chunk */
stripe_len = map->stripe_len;
/* Stripe wher this block falls in */
stripe_nr = div64_u64(offset, stripe_len);
/* Offset of stripe in the chunk */
stripe_offset = stripe_nr * stripe_len;
if (offset < stripe_offset) {
btrfs_crit(fs_info,
"stripe math has gone wrong, stripe_offset=%llu offset=%llu start=%llu logical=%llu stripe_len=%llu",
stripe_offset, offset, em->start, logical, stripe_len);
ret = -EINVAL;
goto out;
}
/* stripe_offset is the offset of this block in its stripe */
stripe_offset = offset - stripe_offset;
data_stripes = nr_data_stripes(map);
if (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
u64 max_len = stripe_len - stripe_offset;
/*
* In case of raid56, we need to know the stripe aligned start
*/
if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
unsigned long full_stripe_len = stripe_len * data_stripes;
raid56_full_stripe_start = offset;
/*
* Allow a write of a full stripe, but make sure we
* don't allow straddling of stripes
*/
raid56_full_stripe_start = div64_u64(raid56_full_stripe_start,
full_stripe_len);
raid56_full_stripe_start *= full_stripe_len;
/*
* For writes to RAID[56], allow a full stripeset across
* all disks. For other RAID types and for RAID[56]
* reads, just allow a single stripe (on a single disk).
*/
if (op == BTRFS_MAP_WRITE) {
max_len = stripe_len * data_stripes -
(offset - raid56_full_stripe_start);
}
}
len = min_t(u64, em->len - offset, max_len);
} else {
len = em->len - offset;
}
io_geom->len = len;
io_geom->offset = offset;
io_geom->stripe_len = stripe_len;
io_geom->stripe_nr = stripe_nr;
io_geom->stripe_offset = stripe_offset;
io_geom->raid56_stripe_offset = raid56_full_stripe_start;
out:
/* once for us */
free_extent_map(em);
return ret;
}
static int __btrfs_map_block(struct btrfs_fs_info *fs_info,
enum btrfs_map_op op,
u64 logical, u64 *length,
struct btrfs_bio **bbio_ret,
int mirror_num, int need_raid_map)
{
struct extent_map *em;
struct map_lookup *map;
u64 stripe_offset;
u64 stripe_nr;
u64 stripe_len;
u32 stripe_index;
int data_stripes;
int i;
int ret = 0;
int num_stripes;
int max_errors = 0;
int tgtdev_indexes = 0;
struct btrfs_bio *bbio = NULL;
struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
int dev_replace_is_ongoing = 0;
int num_alloc_stripes;
int patch_the_first_stripe_for_dev_replace = 0;
u64 physical_to_patch_in_first_stripe = 0;
u64 raid56_full_stripe_start = (u64)-1;
struct btrfs_io_geometry geom;
ASSERT(bbio_ret);
ASSERT(op != BTRFS_MAP_DISCARD);
ret = btrfs_get_io_geometry(fs_info, op, logical, *length, &geom);
if (ret < 0)
return ret;
em = btrfs_get_chunk_map(fs_info, logical, *length);
ASSERT(!IS_ERR(em));
map = em->map_lookup;
*length = geom.len;
stripe_len = geom.stripe_len;
stripe_nr = geom.stripe_nr;
stripe_offset = geom.stripe_offset;
raid56_full_stripe_start = geom.raid56_stripe_offset;
data_stripes = nr_data_stripes(map);
down_read(&dev_replace->rwsem);
dev_replace_is_ongoing = btrfs_dev_replace_is_ongoing(dev_replace);
/*
* Hold the semaphore for read during the whole operation, write is
* requested at commit time but must wait.
*/
if (!dev_replace_is_ongoing)
up_read(&dev_replace->rwsem);
if (dev_replace_is_ongoing && mirror_num == map->num_stripes + 1 &&
!need_full_stripe(op) && dev_replace->tgtdev != NULL) {
ret = get_extra_mirror_from_replace(fs_info, logical, *length,
dev_replace->srcdev->devid,
&mirror_num,
&physical_to_patch_in_first_stripe);
if (ret)
goto out;
else
patch_the_first_stripe_for_dev_replace = 1;
} else if (mirror_num > map->num_stripes) {
mirror_num = 0;
}
num_stripes = 1;
stripe_index = 0;
if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
stripe_nr = div_u64_rem(stripe_nr, map->num_stripes,
&stripe_index);
if (!need_full_stripe(op))
mirror_num = 1;
} else if (map->type & BTRFS_BLOCK_GROUP_RAID1_MASK) {
if (need_full_stripe(op))
num_stripes = map->num_stripes;
else if (mirror_num)
stripe_index = mirror_num - 1;
else {
stripe_index = find_live_mirror(fs_info, map, 0,
dev_replace_is_ongoing);
mirror_num = stripe_index + 1;
}
} else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
if (need_full_stripe(op)) {
num_stripes = map->num_stripes;
} else if (mirror_num) {
stripe_index = mirror_num - 1;
} else {
mirror_num = 1;
}
} else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
u32 factor = map->num_stripes / map->sub_stripes;
stripe_nr = div_u64_rem(stripe_nr, factor, &stripe_index);
stripe_index *= map->sub_stripes;
if (need_full_stripe(op))
num_stripes = map->sub_stripes;
else if (mirror_num)
stripe_index += mirror_num - 1;
else {
int old_stripe_index = stripe_index;
stripe_index = find_live_mirror(fs_info, map,
stripe_index,
dev_replace_is_ongoing);
mirror_num = stripe_index - old_stripe_index + 1;
}
} else if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
if (need_raid_map && (need_full_stripe(op) || mirror_num > 1)) {
/* push stripe_nr back to the start of the full stripe */
stripe_nr = div64_u64(raid56_full_stripe_start,
stripe_len * data_stripes);
/* RAID[56] write or recovery. Return all stripes */
num_stripes = map->num_stripes;
max_errors = nr_parity_stripes(map);
*length = map->stripe_len;
stripe_index = 0;
stripe_offset = 0;
} else {
/*
* Mirror #0 or #1 means the original data block.
* Mirror #2 is RAID5 parity block.
* Mirror #3 is RAID6 Q block.
*/
stripe_nr = div_u64_rem(stripe_nr,
data_stripes, &stripe_index);
if (mirror_num > 1)
stripe_index = data_stripes + mirror_num - 2;
/* We distribute the parity blocks across stripes */
div_u64_rem(stripe_nr + stripe_index, map->num_stripes,
&stripe_index);
if (!need_full_stripe(op) && mirror_num <= 1)
mirror_num = 1;
}
} else {
/*
* after this, stripe_nr is the number of stripes on this
* device we have to walk to find the data, and stripe_index is
* the number of our device in the stripe array
*/
stripe_nr = div_u64_rem(stripe_nr, map->num_stripes,
&stripe_index);
mirror_num = stripe_index + 1;
}
if (stripe_index >= map->num_stripes) {
btrfs_crit(fs_info,
"stripe index math went horribly wrong, got stripe_index=%u, num_stripes=%u",
stripe_index, map->num_stripes);
ret = -EINVAL;
goto out;
}
num_alloc_stripes = num_stripes;
if (dev_replace_is_ongoing && dev_replace->tgtdev != NULL) {
if (op == BTRFS_MAP_WRITE)
num_alloc_stripes <<= 1;
if (op == BTRFS_MAP_GET_READ_MIRRORS)
num_alloc_stripes++;
tgtdev_indexes = num_stripes;
}
bbio = alloc_btrfs_bio(num_alloc_stripes, tgtdev_indexes);
if (!bbio) {
ret = -ENOMEM;
goto out;
}
if (dev_replace_is_ongoing && dev_replace->tgtdev != NULL)
bbio->tgtdev_map = (int *)(bbio->stripes + num_alloc_stripes);
/* build raid_map */
if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK && need_raid_map &&
(need_full_stripe(op) || mirror_num > 1)) {
u64 tmp;
unsigned rot;
bbio->raid_map = (u64 *)((void *)bbio->stripes +
sizeof(struct btrfs_bio_stripe) *
num_alloc_stripes +
sizeof(int) * tgtdev_indexes);
/* Work out the disk rotation on this stripe-set */
div_u64_rem(stripe_nr, num_stripes, &rot);
/* Fill in the logical address of each stripe */
tmp = stripe_nr * data_stripes;
for (i = 0; i < data_stripes; i++)
bbio->raid_map[(i+rot) % num_stripes] =
em->start + (tmp + i) * map->stripe_len;
bbio->raid_map[(i+rot) % map->num_stripes] = RAID5_P_STRIPE;
if (map->type & BTRFS_BLOCK_GROUP_RAID6)
bbio->raid_map[(i+rot+1) % num_stripes] =
RAID6_Q_STRIPE;
}
for (i = 0; i < num_stripes; i++) {
bbio->stripes[i].physical =
map->stripes[stripe_index].physical +
stripe_offset +
stripe_nr * map->stripe_len;
bbio->stripes[i].dev =
map->stripes[stripe_index].dev;
stripe_index++;
}
if (need_full_stripe(op))
max_errors = btrfs_chunk_max_errors(map);
if (bbio->raid_map)
sort_parity_stripes(bbio, num_stripes);
if (dev_replace_is_ongoing && dev_replace->tgtdev != NULL &&
need_full_stripe(op)) {
handle_ops_on_dev_replace(op, &bbio, dev_replace, &num_stripes,
&max_errors);
}
*bbio_ret = bbio;
bbio->map_type = map->type;
bbio->num_stripes = num_stripes;
bbio->max_errors = max_errors;
bbio->mirror_num = mirror_num;
/*
* this is the case that REQ_READ && dev_replace_is_ongoing &&
* mirror_num == num_stripes + 1 && dev_replace target drive is
* available as a mirror
*/
if (patch_the_first_stripe_for_dev_replace && num_stripes > 0) {
WARN_ON(num_stripes > 1);
bbio->stripes[0].dev = dev_replace->tgtdev;
bbio->stripes[0].physical = physical_to_patch_in_first_stripe;
bbio->mirror_num = map->num_stripes + 1;
}
out:
if (dev_replace_is_ongoing) {
lockdep_assert_held(&dev_replace->rwsem);
/* Unlock and let waiting writers proceed */
up_read(&dev_replace->rwsem);
}
free_extent_map(em);
return ret;
}
int btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
u64 logical, u64 *length,
struct btrfs_bio **bbio_ret, int mirror_num)
{
if (op == BTRFS_MAP_DISCARD)
return __btrfs_map_block_for_discard(fs_info, logical,
length, bbio_ret);
return __btrfs_map_block(fs_info, op, logical, length, bbio_ret,
mirror_num, 0);
}
/* For Scrub/replace */
int btrfs_map_sblock(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
u64 logical, u64 *length,
struct btrfs_bio **bbio_ret)
{
return __btrfs_map_block(fs_info, op, logical, length, bbio_ret, 0, 1);
}
static inline void btrfs_end_bbio(struct btrfs_bio *bbio, struct bio *bio)
{
bio->bi_private = bbio->private;
bio->bi_end_io = bbio->end_io;
bio_endio(bio);
btrfs_put_bbio(bbio);
}
static void btrfs_end_bio(struct bio *bio)
{
struct btrfs_bio *bbio = bio->bi_private;
int is_orig_bio = 0;
if (bio->bi_status) {
atomic_inc(&bbio->error);
if (bio->bi_status == BLK_STS_IOERR ||
bio->bi_status == BLK_STS_TARGET) {
unsigned int stripe_index =
btrfs_io_bio(bio)->stripe_index;
struct btrfs_device *dev;
BUG_ON(stripe_index >= bbio->num_stripes);
dev = bbio->stripes[stripe_index].dev;
if (dev->bdev) {
if (bio_op(bio) == REQ_OP_WRITE)
btrfs_dev_stat_inc_and_print(dev,
BTRFS_DEV_STAT_WRITE_ERRS);
else if (!(bio->bi_opf & REQ_RAHEAD))
btrfs_dev_stat_inc_and_print(dev,
BTRFS_DEV_STAT_READ_ERRS);
if (bio->bi_opf & REQ_PREFLUSH)
btrfs_dev_stat_inc_and_print(dev,
BTRFS_DEV_STAT_FLUSH_ERRS);
}
}
}
if (bio == bbio->orig_bio)
is_orig_bio = 1;
btrfs_bio_counter_dec(bbio->fs_info);
if (atomic_dec_and_test(&bbio->stripes_pending)) {
if (!is_orig_bio) {
bio_put(bio);
bio = bbio->orig_bio;
}
btrfs_io_bio(bio)->mirror_num = bbio->mirror_num;
/* only send an error to the higher layers if it is
* beyond the tolerance of the btrfs bio
*/
if (atomic_read(&bbio->error) > bbio->max_errors) {
bio->bi_status = BLK_STS_IOERR;
} else {
/*
* this bio is actually up to date, we didn't
* go over the max number of errors
*/
bio->bi_status = BLK_STS_OK;
}
btrfs_end_bbio(bbio, bio);
} else if (!is_orig_bio) {
bio_put(bio);
}
}
static void submit_stripe_bio(struct btrfs_bio *bbio, struct bio *bio,
u64 physical, int dev_nr)
{
struct btrfs_device *dev = bbio->stripes[dev_nr].dev;
struct btrfs_fs_info *fs_info = bbio->fs_info;
bio->bi_private = bbio;
btrfs_io_bio(bio)->stripe_index = dev_nr;
bio->bi_end_io = btrfs_end_bio;
bio->bi_iter.bi_sector = physical >> 9;
btrfs_debug_in_rcu(fs_info,
"btrfs_map_bio: rw %d 0x%x, sector=%llu, dev=%lu (%s id %llu), size=%u",
bio_op(bio), bio->bi_opf, (u64)bio->bi_iter.bi_sector,
(unsigned long)dev->bdev->bd_dev, rcu_str_deref(dev->name),
dev->devid, bio->bi_iter.bi_size);
bio_set_dev(bio, dev->bdev);
btrfs_bio_counter_inc_noblocked(fs_info);
btrfsic_submit_bio(bio);
}
static void bbio_error(struct btrfs_bio *bbio, struct bio *bio, u64 logical)
{
atomic_inc(&bbio->error);
if (atomic_dec_and_test(&bbio->stripes_pending)) {
/* Should be the original bio. */
WARN_ON(bio != bbio->orig_bio);
btrfs_io_bio(bio)->mirror_num = bbio->mirror_num;
bio->bi_iter.bi_sector = logical >> 9;
if (atomic_read(&bbio->error) > bbio->max_errors)
bio->bi_status = BLK_STS_IOERR;
else
bio->bi_status = BLK_STS_OK;
btrfs_end_bbio(bbio, bio);
}
}
blk_status_t btrfs_map_bio(struct btrfs_fs_info *fs_info, struct bio *bio,
int mirror_num)
{
struct btrfs_device *dev;
struct bio *first_bio = bio;
u64 logical = (u64)bio->bi_iter.bi_sector << 9;
u64 length = 0;
u64 map_length;
int ret;
int dev_nr;
int total_devs;
struct btrfs_bio *bbio = NULL;
length = bio->bi_iter.bi_size;
map_length = length;
btrfs_bio_counter_inc_blocked(fs_info);
ret = __btrfs_map_block(fs_info, btrfs_op(bio), logical,
&map_length, &bbio, mirror_num, 1);
if (ret) {
btrfs_bio_counter_dec(fs_info);
return errno_to_blk_status(ret);
}
total_devs = bbio->num_stripes;
bbio->orig_bio = first_bio;
bbio->private = first_bio->bi_private;
bbio->end_io = first_bio->bi_end_io;
bbio->fs_info = fs_info;
atomic_set(&bbio->stripes_pending, bbio->num_stripes);
if ((bbio->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK) &&
((bio_op(bio) == REQ_OP_WRITE) || (mirror_num > 1))) {
/* In this case, map_length has been set to the length of
a single stripe; not the whole write */
if (bio_op(bio) == REQ_OP_WRITE) {
ret = raid56_parity_write(fs_info, bio, bbio,
map_length);
} else {
ret = raid56_parity_recover(fs_info, bio, bbio,
map_length, mirror_num, 1);
}
btrfs_bio_counter_dec(fs_info);
return errno_to_blk_status(ret);
}
if (map_length < length) {
btrfs_crit(fs_info,
"mapping failed logical %llu bio len %llu len %llu",
logical, length, map_length);
BUG();
}
for (dev_nr = 0; dev_nr < total_devs; dev_nr++) {
dev = bbio->stripes[dev_nr].dev;
if (!dev || !dev->bdev || test_bit(BTRFS_DEV_STATE_MISSING,
&dev->dev_state) ||
(bio_op(first_bio) == REQ_OP_WRITE &&
!test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state))) {
bbio_error(bbio, first_bio, logical);
continue;
}
if (dev_nr < total_devs - 1)
bio = btrfs_bio_clone(first_bio);
else
bio = first_bio;
submit_stripe_bio(bbio, bio, bbio->stripes[dev_nr].physical,
dev_nr);
}
btrfs_bio_counter_dec(fs_info);
return BLK_STS_OK;
}
/*
* Find a device specified by @devid or @uuid in the list of @fs_devices, or
* return NULL.
*
* If devid and uuid are both specified, the match must be exact, otherwise
* only devid is used.
*
* If @seed is true, traverse through the seed devices.
*/
struct btrfs_device *btrfs_find_device(struct btrfs_fs_devices *fs_devices,
u64 devid, u8 *uuid, u8 *fsid,
bool seed)
{
struct btrfs_device *device;
while (fs_devices) {
if (!fsid ||
!memcmp(fs_devices->metadata_uuid, fsid, BTRFS_FSID_SIZE)) {
list_for_each_entry(device, &fs_devices->devices,
dev_list) {
if (device->devid == devid &&
(!uuid || memcmp(device->uuid, uuid,
BTRFS_UUID_SIZE) == 0))
return device;
}
}
if (seed)
fs_devices = fs_devices->seed;
else
return NULL;
}
return NULL;
}
static struct btrfs_device *add_missing_dev(struct btrfs_fs_devices *fs_devices,
u64 devid, u8 *dev_uuid)
{
struct btrfs_device *device;
device = btrfs_alloc_device(NULL, &devid, dev_uuid);
if (IS_ERR(device))
return device;
list_add(&device->dev_list, &fs_devices->devices);
device->fs_devices = fs_devices;
fs_devices->num_devices++;
set_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state);
fs_devices->missing_devices++;
return device;
}
/**
* btrfs_alloc_device - allocate struct btrfs_device
* @fs_info: used only for generating a new devid, can be NULL if
* devid is provided (i.e. @devid != NULL).
* @devid: a pointer to devid for this device. If NULL a new devid
* is generated.
* @uuid: a pointer to UUID for this device. If NULL a new UUID
* is generated.
*
* Return: a pointer to a new &struct btrfs_device on success; ERR_PTR()
* on error. Returned struct is not linked onto any lists and must be
* destroyed with btrfs_free_device.
*/
struct btrfs_device *btrfs_alloc_device(struct btrfs_fs_info *fs_info,
const u64 *devid,
const u8 *uuid)
{
struct btrfs_device *dev;
u64 tmp;
if (WARN_ON(!devid && !fs_info))
return ERR_PTR(-EINVAL);
dev = __alloc_device();
if (IS_ERR(dev))
return dev;
if (devid)
tmp = *devid;
else {
int ret;
ret = find_next_devid(fs_info, &tmp);
if (ret) {
btrfs_free_device(dev);
return ERR_PTR(ret);
}
}
dev->devid = tmp;
if (uuid)
memcpy(dev->uuid, uuid, BTRFS_UUID_SIZE);
else
generate_random_uuid(dev->uuid);
return dev;
}
static void btrfs_report_missing_device(struct btrfs_fs_info *fs_info,
u64 devid, u8 *uuid, bool error)
{
if (error)
btrfs_err_rl(fs_info, "devid %llu uuid %pU is missing",
devid, uuid);
else
btrfs_warn_rl(fs_info, "devid %llu uuid %pU is missing",
devid, uuid);
}
static u64 calc_stripe_length(u64 type, u64 chunk_len, int num_stripes)
{
int index = btrfs_bg_flags_to_raid_index(type);
int ncopies = btrfs_raid_array[index].ncopies;
const int nparity = btrfs_raid_array[index].nparity;
int data_stripes;
if (nparity)
data_stripes = num_stripes - nparity;
else
data_stripes = num_stripes / ncopies;
return div_u64(chunk_len, data_stripes);
}
static int read_one_chunk(struct btrfs_key *key, struct extent_buffer *leaf,
struct btrfs_chunk *chunk)
{
struct btrfs_fs_info *fs_info = leaf->fs_info;
struct extent_map_tree *map_tree = &fs_info->mapping_tree;
struct map_lookup *map;
struct extent_map *em;
u64 logical;
u64 length;
u64 devid;
u8 uuid[BTRFS_UUID_SIZE];
int num_stripes;
int ret;
int i;
logical = key->offset;
length = btrfs_chunk_length(leaf, chunk);
num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
/*
* Only need to verify chunk item if we're reading from sys chunk array,
* as chunk item in tree block is already verified by tree-checker.
*/
if (leaf->start == BTRFS_SUPER_INFO_OFFSET) {
ret = btrfs_check_chunk_valid(leaf, chunk, logical);
if (ret)
return ret;
}
read_lock(&map_tree->lock);
em = lookup_extent_mapping(map_tree, logical, 1);
read_unlock(&map_tree->lock);
/* already mapped? */
if (em && em->start <= logical && em->start + em->len > logical) {
free_extent_map(em);
return 0;
} else if (em) {
free_extent_map(em);
}
em = alloc_extent_map();
if (!em)
return -ENOMEM;
map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
if (!map) {
free_extent_map(em);
return -ENOMEM;
}
set_bit(EXTENT_FLAG_FS_MAPPING, &em->flags);
em->map_lookup = map;
em->start = logical;
em->len = length;
em->orig_start = 0;
em->block_start = 0;
em->block_len = em->len;
map->num_stripes = num_stripes;
map->io_width = btrfs_chunk_io_width(leaf, chunk);
map->io_align = btrfs_chunk_io_align(leaf, chunk);
map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
map->type = btrfs_chunk_type(leaf, chunk);
map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
map->verified_stripes = 0;
em->orig_block_len = calc_stripe_length(map->type, em->len,
map->num_stripes);
for (i = 0; i < num_stripes; i++) {
map->stripes[i].physical =
btrfs_stripe_offset_nr(leaf, chunk, i);
devid = btrfs_stripe_devid_nr(leaf, chunk, i);
read_extent_buffer(leaf, uuid, (unsigned long)
btrfs_stripe_dev_uuid_nr(chunk, i),
BTRFS_UUID_SIZE);
map->stripes[i].dev = btrfs_find_device(fs_info->fs_devices,
devid, uuid, NULL, true);
if (!map->stripes[i].dev &&
!btrfs_test_opt(fs_info, DEGRADED)) {
free_extent_map(em);
btrfs_report_missing_device(fs_info, devid, uuid, true);
return -ENOENT;
}
if (!map->stripes[i].dev) {
map->stripes[i].dev =
add_missing_dev(fs_info->fs_devices, devid,
uuid);
if (IS_ERR(map->stripes[i].dev)) {
free_extent_map(em);
btrfs_err(fs_info,
"failed to init missing dev %llu: %ld",
devid, PTR_ERR(map->stripes[i].dev));
return PTR_ERR(map->stripes[i].dev);
}
btrfs_report_missing_device(fs_info, devid, uuid, false);
}
set_bit(BTRFS_DEV_STATE_IN_FS_METADATA,
&(map->stripes[i].dev->dev_state));
}
write_lock(&map_tree->lock);
ret = add_extent_mapping(map_tree, em, 0);
write_unlock(&map_tree->lock);
if (ret < 0) {
btrfs_err(fs_info,
"failed to add chunk map, start=%llu len=%llu: %d",
em->start, em->len, ret);
}
free_extent_map(em);
return ret;
}
static void fill_device_from_item(struct extent_buffer *leaf,
struct btrfs_dev_item *dev_item,
struct btrfs_device *device)
{
unsigned long ptr;
device->devid = btrfs_device_id(leaf, dev_item);
device->disk_total_bytes = btrfs_device_total_bytes(leaf, dev_item);
device->total_bytes = device->disk_total_bytes;
device->commit_total_bytes = device->disk_total_bytes;
device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
device->commit_bytes_used = device->bytes_used;
device->type = btrfs_device_type(leaf, dev_item);
device->io_align = btrfs_device_io_align(leaf, dev_item);
device->io_width = btrfs_device_io_width(leaf, dev_item);
device->sector_size = btrfs_device_sector_size(leaf, dev_item);
WARN_ON(device->devid == BTRFS_DEV_REPLACE_DEVID);
clear_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state);
ptr = btrfs_device_uuid(dev_item);
read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
}
static struct btrfs_fs_devices *open_seed_devices(struct btrfs_fs_info *fs_info,
u8 *fsid)
{
struct btrfs_fs_devices *fs_devices;
int ret;
lockdep_assert_held(&uuid_mutex);
ASSERT(fsid);
fs_devices = fs_info->fs_devices->seed;
while (fs_devices) {
if (!memcmp(fs_devices->fsid, fsid, BTRFS_FSID_SIZE))
return fs_devices;
fs_devices = fs_devices->seed;
}
fs_devices = find_fsid(fsid, NULL);
if (!fs_devices) {
if (!btrfs_test_opt(fs_info, DEGRADED))
return ERR_PTR(-ENOENT);
fs_devices = alloc_fs_devices(fsid, NULL);
if (IS_ERR(fs_devices))
return fs_devices;
fs_devices->seeding = true;
fs_devices->opened = 1;
return fs_devices;
}
fs_devices = clone_fs_devices(fs_devices);
if (IS_ERR(fs_devices))
return fs_devices;
ret = open_fs_devices(fs_devices, FMODE_READ, fs_info->bdev_holder);
if (ret) {
free_fs_devices(fs_devices);
fs_devices = ERR_PTR(ret);
goto out;
}
if (!fs_devices->seeding) {
close_fs_devices(fs_devices);
free_fs_devices(fs_devices);
fs_devices = ERR_PTR(-EINVAL);
goto out;
}
fs_devices->seed = fs_info->fs_devices->seed;
fs_info->fs_devices->seed = fs_devices;
out:
return fs_devices;
}
static int read_one_dev(struct extent_buffer *leaf,
struct btrfs_dev_item *dev_item)
{
struct btrfs_fs_info *fs_info = leaf->fs_info;
struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
struct btrfs_device *device;
u64 devid;
int ret;
u8 fs_uuid[BTRFS_FSID_SIZE];
u8 dev_uuid[BTRFS_UUID_SIZE];
devid = btrfs_device_id(leaf, dev_item);
read_extent_buffer(leaf, dev_uuid, btrfs_device_uuid(dev_item),
BTRFS_UUID_SIZE);
read_extent_buffer(leaf, fs_uuid, btrfs_device_fsid(dev_item),
BTRFS_FSID_SIZE);
if (memcmp(fs_uuid, fs_devices->metadata_uuid, BTRFS_FSID_SIZE)) {
fs_devices = open_seed_devices(fs_info, fs_uuid);
if (IS_ERR(fs_devices))
return PTR_ERR(fs_devices);
}
device = btrfs_find_device(fs_info->fs_devices, devid, dev_uuid,
fs_uuid, true);
if (!device) {
if (!btrfs_test_opt(fs_info, DEGRADED)) {
btrfs_report_missing_device(fs_info, devid,
dev_uuid, true);
return -ENOENT;
}
device = add_missing_dev(fs_devices, devid, dev_uuid);
if (IS_ERR(device)) {
btrfs_err(fs_info,
"failed to add missing dev %llu: %ld",
devid, PTR_ERR(device));
return PTR_ERR(device);
}
btrfs_report_missing_device(fs_info, devid, dev_uuid, false);
} else {
if (!device->bdev) {
if (!btrfs_test_opt(fs_info, DEGRADED)) {
btrfs_report_missing_device(fs_info,
devid, dev_uuid, true);
return -ENOENT;
}
btrfs_report_missing_device(fs_info, devid,
dev_uuid, false);
}
if (!device->bdev &&
!test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state)) {
/*
* this happens when a device that was properly setup
* in the device info lists suddenly goes bad.
* device->bdev is NULL, and so we have to set
* device->missing to one here
*/
device->fs_devices->missing_devices++;
set_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state);
}
/* Move the device to its own fs_devices */
if (device->fs_devices != fs_devices) {
ASSERT(test_bit(BTRFS_DEV_STATE_MISSING,
&device->dev_state));
list_move(&device->dev_list, &fs_devices->devices);
device->fs_devices->num_devices--;
fs_devices->num_devices++;
device->fs_devices->missing_devices--;
fs_devices->missing_devices++;
device->fs_devices = fs_devices;
}
}
if (device->fs_devices != fs_info->fs_devices) {
BUG_ON(test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state));
if (device->generation !=
btrfs_device_generation(leaf, dev_item))
return -EINVAL;
}
fill_device_from_item(leaf, dev_item, device);
set_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state) &&
!test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) {
device->fs_devices->total_rw_bytes += device->total_bytes;
atomic64_add(device->total_bytes - device->bytes_used,
&fs_info->free_chunk_space);
}
ret = 0;
return ret;
}
int btrfs_read_sys_array(struct btrfs_fs_info *fs_info)
{
struct btrfs_root *root = fs_info->tree_root;
struct btrfs_super_block *super_copy = fs_info->super_copy;
struct extent_buffer *sb;
struct btrfs_disk_key *disk_key;
struct btrfs_chunk *chunk;
u8 *array_ptr;
unsigned long sb_array_offset;
int ret = 0;
u32 num_stripes;
u32 array_size;
u32 len = 0;
u32 cur_offset;
u64 type;
struct btrfs_key key;
ASSERT(BTRFS_SUPER_INFO_SIZE <= fs_info->nodesize);
/*
* This will create extent buffer of nodesize, superblock size is
* fixed to BTRFS_SUPER_INFO_SIZE. If nodesize > sb size, this will
* overallocate but we can keep it as-is, only the first page is used.
*/
sb = btrfs_find_create_tree_block(fs_info, BTRFS_SUPER_INFO_OFFSET);
if (IS_ERR(sb))
return PTR_ERR(sb);
set_extent_buffer_uptodate(sb);
btrfs_set_buffer_lockdep_class(root->root_key.objectid, sb, 0);
/*
* The sb extent buffer is artificial and just used to read the system array.
* set_extent_buffer_uptodate() call does not properly mark all it's
* pages up-to-date when the page is larger: extent does not cover the
* whole page and consequently check_page_uptodate does not find all
* the page's extents up-to-date (the hole beyond sb),
* write_extent_buffer then triggers a WARN_ON.
*
* Regular short extents go through mark_extent_buffer_dirty/writeback cycle,
* but sb spans only this function. Add an explicit SetPageUptodate call
* to silence the warning eg. on PowerPC 64.
*/
if (PAGE_SIZE > BTRFS_SUPER_INFO_SIZE)
SetPageUptodate(sb->pages[0]);
write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
array_size = btrfs_super_sys_array_size(super_copy);
array_ptr = super_copy->sys_chunk_array;
sb_array_offset = offsetof(struct btrfs_super_block, sys_chunk_array);
cur_offset = 0;
while (cur_offset < array_size) {
disk_key = (struct btrfs_disk_key *)array_ptr;
len = sizeof(*disk_key);
if (cur_offset + len > array_size)
goto out_short_read;
btrfs_disk_key_to_cpu(&key, disk_key);
array_ptr += len;
sb_array_offset += len;
cur_offset += len;
if (key.type != BTRFS_CHUNK_ITEM_KEY) {
btrfs_err(fs_info,
"unexpected item type %u in sys_array at offset %u",
(u32)key.type, cur_offset);
ret = -EIO;
break;
}
chunk = (struct btrfs_chunk *)sb_array_offset;
/*
* At least one btrfs_chunk with one stripe must be present,
* exact stripe count check comes afterwards
*/
len = btrfs_chunk_item_size(1);
if (cur_offset + len > array_size)
goto out_short_read;
num_stripes = btrfs_chunk_num_stripes(sb, chunk);
if (!num_stripes) {
btrfs_err(fs_info,
"invalid number of stripes %u in sys_array at offset %u",
num_stripes, cur_offset);
ret = -EIO;
break;
}
type = btrfs_chunk_type(sb, chunk);
if ((type & BTRFS_BLOCK_GROUP_SYSTEM) == 0) {
btrfs_err(fs_info,
"invalid chunk type %llu in sys_array at offset %u",
type, cur_offset);
ret = -EIO;
break;
}
len = btrfs_chunk_item_size(num_stripes);
if (cur_offset + len > array_size)
goto out_short_read;
ret = read_one_chunk(&key, sb, chunk);
if (ret)
break;
array_ptr += len;
sb_array_offset += len;
cur_offset += len;
}
clear_extent_buffer_uptodate(sb);
free_extent_buffer_stale(sb);
return ret;
out_short_read:
btrfs_err(fs_info, "sys_array too short to read %u bytes at offset %u",
len, cur_offset);
clear_extent_buffer_uptodate(sb);
free_extent_buffer_stale(sb);
return -EIO;
}
/*
* Check if all chunks in the fs are OK for read-write degraded mount
*
* If the @failing_dev is specified, it's accounted as missing.
*
* Return true if all chunks meet the minimal RW mount requirements.
* Return false if any chunk doesn't meet the minimal RW mount requirements.
*/
bool btrfs_check_rw_degradable(struct btrfs_fs_info *fs_info,
struct btrfs_device *failing_dev)
{
struct extent_map_tree *map_tree = &fs_info->mapping_tree;
struct extent_map *em;
u64 next_start = 0;
bool ret = true;
read_lock(&map_tree->lock);
em = lookup_extent_mapping(map_tree, 0, (u64)-1);
read_unlock(&map_tree->lock);
/* No chunk at all? Return false anyway */
if (!em) {
ret = false;
goto out;
}
while (em) {
struct map_lookup *map;
int missing = 0;
int max_tolerated;
int i;
map = em->map_lookup;
max_tolerated =
btrfs_get_num_tolerated_disk_barrier_failures(
map->type);
for (i = 0; i < map->num_stripes; i++) {
struct btrfs_device *dev = map->stripes[i].dev;
if (!dev || !dev->bdev ||
test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state) ||
dev->last_flush_error)
missing++;
else if (failing_dev && failing_dev == dev)
missing++;
}
if (missing > max_tolerated) {
if (!failing_dev)
btrfs_warn(fs_info,
"chunk %llu missing %d devices, max tolerance is %d for writable mount",
em->start, missing, max_tolerated);
free_extent_map(em);
ret = false;
goto out;
}
next_start = extent_map_end(em);
free_extent_map(em);
read_lock(&map_tree->lock);
em = lookup_extent_mapping(map_tree, next_start,
(u64)(-1) - next_start);
read_unlock(&map_tree->lock);
}
out:
return ret;
}
int btrfs_read_chunk_tree(struct btrfs_fs_info *fs_info)
{
struct btrfs_root *root = fs_info->chunk_root;
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_key key;
struct btrfs_key found_key;
int ret;
int slot;
u64 total_dev = 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
/*
* uuid_mutex is needed only if we are mounting a sprout FS
* otherwise we don't need it.
*/
mutex_lock(&uuid_mutex);
mutex_lock(&fs_info->chunk_mutex);
/*
* Read all device items, and then all the chunk items. All
* device items are found before any chunk item (their object id
* is smaller than the lowest possible object id for a chunk
* item - BTRFS_FIRST_CHUNK_TREE_OBJECTID).
*/
key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
key.offset = 0;
key.type = 0;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto error;
while (1) {
leaf = path->nodes[0];
slot = path->slots[0];
if (slot >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, path);
if (ret == 0)
continue;
if (ret < 0)
goto error;
break;
}
btrfs_item_key_to_cpu(leaf, &found_key, slot);
if (found_key.type == BTRFS_DEV_ITEM_KEY) {
struct btrfs_dev_item *dev_item;
dev_item = btrfs_item_ptr(leaf, slot,
struct btrfs_dev_item);
ret = read_one_dev(leaf, dev_item);
if (ret)
goto error;
total_dev++;
} else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
struct btrfs_chunk *chunk;
chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
ret = read_one_chunk(&found_key, leaf, chunk);
if (ret)
goto error;
}
path->slots[0]++;
}
/*
* After loading chunk tree, we've got all device information,
* do another round of validation checks.
*/
if (total_dev != fs_info->fs_devices->total_devices) {
btrfs_err(fs_info,
"super_num_devices %llu mismatch with num_devices %llu found here",
btrfs_super_num_devices(fs_info->super_copy),
total_dev);
ret = -EINVAL;
goto error;
}
if (btrfs_super_total_bytes(fs_info->super_copy) <
fs_info->fs_devices->total_rw_bytes) {
btrfs_err(fs_info,
"super_total_bytes %llu mismatch with fs_devices total_rw_bytes %llu",
btrfs_super_total_bytes(fs_info->super_copy),
fs_info->fs_devices->total_rw_bytes);
ret = -EINVAL;
goto error;
}
ret = 0;
error:
mutex_unlock(&fs_info->chunk_mutex);
mutex_unlock(&uuid_mutex);
btrfs_free_path(path);
return ret;
}
void btrfs_init_devices_late(struct btrfs_fs_info *fs_info)
{
struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
struct btrfs_device *device;
while (fs_devices) {
mutex_lock(&fs_devices->device_list_mutex);
list_for_each_entry(device, &fs_devices->devices, dev_list)
device->fs_info = fs_info;
mutex_unlock(&fs_devices->device_list_mutex);
fs_devices = fs_devices->seed;
}
}
static u64 btrfs_dev_stats_value(const struct extent_buffer *eb,
const struct btrfs_dev_stats_item *ptr,
int index)
{
u64 val;
read_extent_buffer(eb, &val,
offsetof(struct btrfs_dev_stats_item, values) +
((unsigned long)ptr) + (index * sizeof(u64)),
sizeof(val));
return val;
}
static void btrfs_set_dev_stats_value(struct extent_buffer *eb,
struct btrfs_dev_stats_item *ptr,
int index, u64 val)
{
write_extent_buffer(eb, &val,
offsetof(struct btrfs_dev_stats_item, values) +
((unsigned long)ptr) + (index * sizeof(u64)),
sizeof(val));
}
int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info)
{
struct btrfs_key key;
struct btrfs_root *dev_root = fs_info->dev_root;
struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
struct extent_buffer *eb;
int slot;
int ret = 0;
struct btrfs_device *device;
struct btrfs_path *path = NULL;
int i;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
mutex_lock(&fs_devices->device_list_mutex);
list_for_each_entry(device, &fs_devices->devices, dev_list) {
int item_size;
struct btrfs_dev_stats_item *ptr;
key.objectid = BTRFS_DEV_STATS_OBJECTID;
key.type = BTRFS_PERSISTENT_ITEM_KEY;
key.offset = device->devid;
ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0);
if (ret) {
for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
btrfs_dev_stat_set(device, i, 0);
device->dev_stats_valid = 1;
btrfs_release_path(path);
continue;
}
slot = path->slots[0];
eb = path->nodes[0];
item_size = btrfs_item_size_nr(eb, slot);
ptr = btrfs_item_ptr(eb, slot,
struct btrfs_dev_stats_item);
for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) {
if (item_size >= (1 + i) * sizeof(__le64))
btrfs_dev_stat_set(device, i,
btrfs_dev_stats_value(eb, ptr, i));
else
btrfs_dev_stat_set(device, i, 0);
}
device->dev_stats_valid = 1;
btrfs_dev_stat_print_on_load(device);
btrfs_release_path(path);
}
mutex_unlock(&fs_devices->device_list_mutex);
btrfs_free_path(path);
return ret < 0 ? ret : 0;
}
static int update_dev_stat_item(struct btrfs_trans_handle *trans,
struct btrfs_device *device)
{
struct btrfs_fs_info *fs_info = trans->fs_info;
struct btrfs_root *dev_root = fs_info->dev_root;
struct btrfs_path *path;
struct btrfs_key key;
struct extent_buffer *eb;
struct btrfs_dev_stats_item *ptr;
int ret;
int i;
key.objectid = BTRFS_DEV_STATS_OBJECTID;
key.type = BTRFS_PERSISTENT_ITEM_KEY;
key.offset = device->devid;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1);
if (ret < 0) {
btrfs_warn_in_rcu(fs_info,
"error %d while searching for dev_stats item for device %s",
ret, rcu_str_deref(device->name));
goto out;
}
if (ret == 0 &&
btrfs_item_size_nr(path->nodes[0], path->slots[0]) < sizeof(*ptr)) {
/* need to delete old one and insert a new one */
ret = btrfs_del_item(trans, dev_root, path);
if (ret != 0) {
btrfs_warn_in_rcu(fs_info,
"delete too small dev_stats item for device %s failed %d",
rcu_str_deref(device->name), ret);
goto out;
}
ret = 1;
}
if (ret == 1) {
/* need to insert a new item */
btrfs_release_path(path);
ret = btrfs_insert_empty_item(trans, dev_root, path,
&key, sizeof(*ptr));
if (ret < 0) {
btrfs_warn_in_rcu(fs_info,
"insert dev_stats item for device %s failed %d",
rcu_str_deref(device->name), ret);
goto out;
}
}
eb = path->nodes[0];
ptr = btrfs_item_ptr(eb, path->slots[0], struct btrfs_dev_stats_item);
for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
btrfs_set_dev_stats_value(eb, ptr, i,
btrfs_dev_stat_read(device, i));
btrfs_mark_buffer_dirty(eb);
out:
btrfs_free_path(path);
return ret;
}
/*
* called from commit_transaction. Writes all changed device stats to disk.
*/
int btrfs_run_dev_stats(struct btrfs_trans_handle *trans)
{
struct btrfs_fs_info *fs_info = trans->fs_info;
struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
struct btrfs_device *device;
int stats_cnt;
int ret = 0;
mutex_lock(&fs_devices->device_list_mutex);
list_for_each_entry(device, &fs_devices->devices, dev_list) {
stats_cnt = atomic_read(&device->dev_stats_ccnt);
if (!device->dev_stats_valid || stats_cnt == 0)
continue;
/*
* There is a LOAD-LOAD control dependency between the value of
* dev_stats_ccnt and updating the on-disk values which requires
* reading the in-memory counters. Such control dependencies
* require explicit read memory barriers.
*
* This memory barriers pairs with smp_mb__before_atomic in
* btrfs_dev_stat_inc/btrfs_dev_stat_set and with the full
* barrier implied by atomic_xchg in
* btrfs_dev_stats_read_and_reset
*/
smp_rmb();
ret = update_dev_stat_item(trans, device);
if (!ret)
atomic_sub(stats_cnt, &device->dev_stats_ccnt);
}
mutex_unlock(&fs_devices->device_list_mutex);
return ret;
}
void btrfs_dev_stat_inc_and_print(struct btrfs_device *dev, int index)
{
btrfs_dev_stat_inc(dev, index);
btrfs_dev_stat_print_on_error(dev);
}
static void btrfs_dev_stat_print_on_error(struct btrfs_device *dev)
{
if (!dev->dev_stats_valid)
return;
btrfs_err_rl_in_rcu(dev->fs_info,
"bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u",
rcu_str_deref(dev->name),
btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_CORRUPTION_ERRS),
btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_GENERATION_ERRS));
}
static void btrfs_dev_stat_print_on_load(struct btrfs_device *dev)
{
int i;
for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
if (btrfs_dev_stat_read(dev, i) != 0)
break;
if (i == BTRFS_DEV_STAT_VALUES_MAX)
return; /* all values == 0, suppress message */
btrfs_info_in_rcu(dev->fs_info,
"bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u",
rcu_str_deref(dev->name),
btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_CORRUPTION_ERRS),
btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_GENERATION_ERRS));
}
int btrfs_get_dev_stats(struct btrfs_fs_info *fs_info,
struct btrfs_ioctl_get_dev_stats *stats)
{
struct btrfs_device *dev;
struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
int i;
mutex_lock(&fs_devices->device_list_mutex);
dev = btrfs_find_device(fs_info->fs_devices, stats->devid, NULL, NULL,
true);
mutex_unlock(&fs_devices->device_list_mutex);
if (!dev) {
btrfs_warn(fs_info, "get dev_stats failed, device not found");
return -ENODEV;
} else if (!dev->dev_stats_valid) {
btrfs_warn(fs_info, "get dev_stats failed, not yet valid");
return -ENODEV;
} else if (stats->flags & BTRFS_DEV_STATS_RESET) {
for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) {
if (stats->nr_items > i)
stats->values[i] =
btrfs_dev_stat_read_and_reset(dev, i);
else
btrfs_dev_stat_set(dev, i, 0);
}
btrfs_info(fs_info, "device stats zeroed by %s (%d)",
current->comm, task_pid_nr(current));
} else {
for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
if (stats->nr_items > i)
stats->values[i] = btrfs_dev_stat_read(dev, i);
}
if (stats->nr_items > BTRFS_DEV_STAT_VALUES_MAX)
stats->nr_items = BTRFS_DEV_STAT_VALUES_MAX;
return 0;
}
/*
* Update the size and bytes used for each device where it changed. This is
* delayed since we would otherwise get errors while writing out the
* superblocks.
*
* Must be invoked during transaction commit.
*/
void btrfs_commit_device_sizes(struct btrfs_transaction *trans)
{
struct btrfs_device *curr, *next;
ASSERT(trans->state == TRANS_STATE_COMMIT_DOING);
if (list_empty(&trans->dev_update_list))
return;
/*
* We don't need the device_list_mutex here. This list is owned by the
* transaction and the transaction must complete before the device is
* released.
*/
mutex_lock(&trans->fs_info->chunk_mutex);
list_for_each_entry_safe(curr, next, &trans->dev_update_list,
post_commit_list) {
list_del_init(&curr->post_commit_list);
curr->commit_total_bytes = curr->disk_total_bytes;
curr->commit_bytes_used = curr->bytes_used;
}
mutex_unlock(&trans->fs_info->chunk_mutex);
}
void btrfs_set_fs_info_ptr(struct btrfs_fs_info *fs_info)
{
struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
while (fs_devices) {
fs_devices->fs_info = fs_info;
fs_devices = fs_devices->seed;
}
}
void btrfs_reset_fs_info_ptr(struct btrfs_fs_info *fs_info)
{
struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
while (fs_devices) {
fs_devices->fs_info = NULL;
fs_devices = fs_devices->seed;
}
}
/*
* Multiplicity factor for simple profiles: DUP, RAID1-like and RAID10.
*/
int btrfs_bg_type_to_factor(u64 flags)
{
const int index = btrfs_bg_flags_to_raid_index(flags);
return btrfs_raid_array[index].ncopies;
}
static int verify_one_dev_extent(struct btrfs_fs_info *fs_info,
u64 chunk_offset, u64 devid,
u64 physical_offset, u64 physical_len)
{
struct extent_map_tree *em_tree = &fs_info->mapping_tree;
struct extent_map *em;
struct map_lookup *map;
struct btrfs_device *dev;
u64 stripe_len;
bool found = false;
int ret = 0;
int i;
read_lock(&em_tree->lock);
em = lookup_extent_mapping(em_tree, chunk_offset, 1);
read_unlock(&em_tree->lock);
if (!em) {
btrfs_err(fs_info,
"dev extent physical offset %llu on devid %llu doesn't have corresponding chunk",
physical_offset, devid);
ret = -EUCLEAN;
goto out;
}
map = em->map_lookup;
stripe_len = calc_stripe_length(map->type, em->len, map->num_stripes);
if (physical_len != stripe_len) {
btrfs_err(fs_info,
"dev extent physical offset %llu on devid %llu length doesn't match chunk %llu, have %llu expect %llu",
physical_offset, devid, em->start, physical_len,
stripe_len);
ret = -EUCLEAN;
goto out;
}
for (i = 0; i < map->num_stripes; i++) {
if (map->stripes[i].dev->devid == devid &&
map->stripes[i].physical == physical_offset) {
found = true;
if (map->verified_stripes >= map->num_stripes) {
btrfs_err(fs_info,
"too many dev extents for chunk %llu found",
em->start);
ret = -EUCLEAN;
goto out;
}
map->verified_stripes++;
break;
}
}
if (!found) {
btrfs_err(fs_info,
"dev extent physical offset %llu devid %llu has no corresponding chunk",
physical_offset, devid);
ret = -EUCLEAN;
}
/* Make sure no dev extent is beyond device bondary */
dev = btrfs_find_device(fs_info->fs_devices, devid, NULL, NULL, true);
if (!dev) {
btrfs_err(fs_info, "failed to find devid %llu", devid);
ret = -EUCLEAN;
goto out;
}
/* It's possible this device is a dummy for seed device */
if (dev->disk_total_bytes == 0) {
dev = btrfs_find_device(fs_info->fs_devices->seed, devid, NULL,
NULL, false);
if (!dev) {
btrfs_err(fs_info, "failed to find seed devid %llu",
devid);
ret = -EUCLEAN;
goto out;
}
}
if (physical_offset + physical_len > dev->disk_total_bytes) {
btrfs_err(fs_info,
"dev extent devid %llu physical offset %llu len %llu is beyond device boundary %llu",
devid, physical_offset, physical_len,
dev->disk_total_bytes);
ret = -EUCLEAN;
goto out;
}
out:
free_extent_map(em);
return ret;
}
static int verify_chunk_dev_extent_mapping(struct btrfs_fs_info *fs_info)
{
struct extent_map_tree *em_tree = &fs_info->mapping_tree;
struct extent_map *em;
struct rb_node *node;
int ret = 0;
read_lock(&em_tree->lock);
for (node = rb_first_cached(&em_tree->map); node; node = rb_next(node)) {
em = rb_entry(node, struct extent_map, rb_node);
if (em->map_lookup->num_stripes !=
em->map_lookup->verified_stripes) {
btrfs_err(fs_info,
"chunk %llu has missing dev extent, have %d expect %d",
em->start, em->map_lookup->verified_stripes,
em->map_lookup->num_stripes);
ret = -EUCLEAN;
goto out;
}
}
out:
read_unlock(&em_tree->lock);
return ret;
}
/*
* Ensure that all dev extents are mapped to correct chunk, otherwise
* later chunk allocation/free would cause unexpected behavior.
*
* NOTE: This will iterate through the whole device tree, which should be of
* the same size level as the chunk tree. This slightly increases mount time.
*/
int btrfs_verify_dev_extents(struct btrfs_fs_info *fs_info)
{
struct btrfs_path *path;
struct btrfs_root *root = fs_info->dev_root;
struct btrfs_key key;
u64 prev_devid = 0;
u64 prev_dev_ext_end = 0;
int ret = 0;
key.objectid = 1;
key.type = BTRFS_DEV_EXTENT_KEY;
key.offset = 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->reada = READA_FORWARD;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto out;
if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
ret = btrfs_next_item(root, path);
if (ret < 0)
goto out;
/* No dev extents at all? Not good */
if (ret > 0) {
ret = -EUCLEAN;
goto out;
}
}
while (1) {
struct extent_buffer *leaf = path->nodes[0];
struct btrfs_dev_extent *dext;
int slot = path->slots[0];
u64 chunk_offset;
u64 physical_offset;
u64 physical_len;
u64 devid;
btrfs_item_key_to_cpu(leaf, &key, slot);
if (key.type != BTRFS_DEV_EXTENT_KEY)
break;
devid = key.objectid;
physical_offset = key.offset;
dext = btrfs_item_ptr(leaf, slot, struct btrfs_dev_extent);
chunk_offset = btrfs_dev_extent_chunk_offset(leaf, dext);
physical_len = btrfs_dev_extent_length(leaf, dext);
/* Check if this dev extent overlaps with the previous one */
if (devid == prev_devid && physical_offset < prev_dev_ext_end) {
btrfs_err(fs_info,
"dev extent devid %llu physical offset %llu overlap with previous dev extent end %llu",
devid, physical_offset, prev_dev_ext_end);
ret = -EUCLEAN;
goto out;
}
ret = verify_one_dev_extent(fs_info, chunk_offset, devid,
physical_offset, physical_len);
if (ret < 0)
goto out;
prev_devid = devid;
prev_dev_ext_end = physical_offset + physical_len;
ret = btrfs_next_item(root, path);
if (ret < 0)
goto out;
if (ret > 0) {
ret = 0;
break;
}
}
/* Ensure all chunks have corresponding dev extents */
ret = verify_chunk_dev_extent_mapping(fs_info);
out:
btrfs_free_path(path);
return ret;
}
/*
* Check whether the given block group or device is pinned by any inode being
* used as a swapfile.
*/
bool btrfs_pinned_by_swapfile(struct btrfs_fs_info *fs_info, void *ptr)
{
struct btrfs_swapfile_pin *sp;
struct rb_node *node;
spin_lock(&fs_info->swapfile_pins_lock);
node = fs_info->swapfile_pins.rb_node;
while (node) {
sp = rb_entry(node, struct btrfs_swapfile_pin, node);
if (ptr < sp->ptr)
node = node->rb_left;
else if (ptr > sp->ptr)
node = node->rb_right;
else
break;
}
spin_unlock(&fs_info->swapfile_pins_lock);
return node != NULL;
}
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