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linux/fs/btrfs/scrub.c
Filipe Manana 0124855ff1 btrfs: add and use helpers for reading and writing last_trans_committed 
Currently the last_trans_committed field of struct btrfs_fs_info is
modified and read without any locking or other protection. For example
early in the fsync path, skip_inode_logging() is called which reads
fs_info->last_trans_committed, but at the same time we can have a
transaction commit completing and updating that field.

In the case of an fsync this is harmless and any data race should be
rare and at most cause an unnecessary logging of an inode.

To avoid data race warnings from tools like KCSAN and other issues such
as load and store tearing (amongst others, see [1]), create helpers to
access the last_trans_committed field of struct btrfs_fs_info using
READ_ONCE() and WRITE_ONCE(), and use these helpers everywhere.

[1] https://lwn.net/Articles/793253/

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-10-12 16:44:17 +02:00

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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2011, 2012 STRATO. All rights reserved.
*/
#include <linux/blkdev.h>
#include <linux/ratelimit.h>
#include <linux/sched/mm.h>
#include <crypto/hash.h>
#include "ctree.h"
#include "discard.h"
#include "volumes.h"
#include "disk-io.h"
#include "ordered-data.h"
#include "transaction.h"
#include "backref.h"
#include "extent_io.h"
#include "dev-replace.h"
#include "raid56.h"
#include "block-group.h"
#include "zoned.h"
#include "fs.h"
#include "accessors.h"
#include "file-item.h"
#include "scrub.h"
#include "raid-stripe-tree.h"
/*
* This is only the first step towards a full-features scrub. It reads all
* extent and super block and verifies the checksums. In case a bad checksum
* is found or the extent cannot be read, good data will be written back if
* any can be found.
*
* Future enhancements:
* - In case an unrepairable extent is encountered, track which files are
* affected and report them
* - track and record media errors, throw out bad devices
* - add a mode to also read unallocated space
*/
struct scrub_ctx;
/*
* The following value only influences the performance.
*
* This detemines how many stripes would be submitted in one go,
* which is 512KiB (BTRFS_STRIPE_LEN * SCRUB_STRIPES_PER_GROUP).
*/
#define SCRUB_STRIPES_PER_GROUP 8
/*
* How many groups we have for each sctx.
*
* This would be 8M per device, the same value as the old scrub in-flight bios
* size limit.
*/
#define SCRUB_GROUPS_PER_SCTX 16
#define SCRUB_TOTAL_STRIPES (SCRUB_GROUPS_PER_SCTX * SCRUB_STRIPES_PER_GROUP)
/*
* The following value times PAGE_SIZE needs to be large enough to match the
* largest node/leaf/sector size that shall be supported.
*/
#define SCRUB_MAX_SECTORS_PER_BLOCK (BTRFS_MAX_METADATA_BLOCKSIZE / SZ_4K)
/* Represent one sector and its needed info to verify the content. */
struct scrub_sector_verification {
bool is_metadata;
union {
/*
* Csum pointer for data csum verification. Should point to a
* sector csum inside scrub_stripe::csums.
*
* NULL if this data sector has no csum.
*/
u8 *csum;
/*
* Extra info for metadata verification. All sectors inside a
* tree block share the same generation.
*/
u64 generation;
};
};
enum scrub_stripe_flags {
/* Set when @mirror_num, @dev, @physical and @logical are set. */
SCRUB_STRIPE_FLAG_INITIALIZED,
/* Set when the read-repair is finished. */
SCRUB_STRIPE_FLAG_REPAIR_DONE,
/*
* Set for data stripes if it's triggered from P/Q stripe.
* During such scrub, we should not report errors in data stripes, nor
* update the accounting.
*/
SCRUB_STRIPE_FLAG_NO_REPORT,
};
#define SCRUB_STRIPE_PAGES (BTRFS_STRIPE_LEN / PAGE_SIZE)
/*
* Represent one contiguous range with a length of BTRFS_STRIPE_LEN.
*/
struct scrub_stripe {
struct scrub_ctx *sctx;
struct btrfs_block_group *bg;
struct page *pages[SCRUB_STRIPE_PAGES];
struct scrub_sector_verification *sectors;
struct btrfs_device *dev;
u64 logical;
u64 physical;
u16 mirror_num;
/* Should be BTRFS_STRIPE_LEN / sectorsize. */
u16 nr_sectors;
/*
* How many data/meta extents are in this stripe. Only for scrub status
* reporting purposes.
*/
u16 nr_data_extents;
u16 nr_meta_extents;
atomic_t pending_io;
wait_queue_head_t io_wait;
wait_queue_head_t repair_wait;
/*
* Indicate the states of the stripe. Bits are defined in
* scrub_stripe_flags enum.
*/
unsigned long state;
/* Indicate which sectors are covered by extent items. */
unsigned long extent_sector_bitmap;
/*
* The errors hit during the initial read of the stripe.
*
* Would be utilized for error reporting and repair.
*
* The remaining init_nr_* records the number of errors hit, only used
* by error reporting.
*/
unsigned long init_error_bitmap;
unsigned int init_nr_io_errors;
unsigned int init_nr_csum_errors;
unsigned int init_nr_meta_errors;
/*
* The following error bitmaps are all for the current status.
* Every time we submit a new read, these bitmaps may be updated.
*
* error_bitmap = io_error_bitmap | csum_error_bitmap | meta_error_bitmap;
*
* IO and csum errors can happen for both metadata and data.
*/
unsigned long error_bitmap;
unsigned long io_error_bitmap;
unsigned long csum_error_bitmap;
unsigned long meta_error_bitmap;
/* For writeback (repair or replace) error reporting. */
unsigned long write_error_bitmap;
/* Writeback can be concurrent, thus we need to protect the bitmap. */
spinlock_t write_error_lock;
/*
* Checksum for the whole stripe if this stripe is inside a data block
* group.
*/
u8 *csums;
struct work_struct work;
};
struct scrub_ctx {
struct scrub_stripe stripes[SCRUB_TOTAL_STRIPES];
struct scrub_stripe *raid56_data_stripes;
struct btrfs_fs_info *fs_info;
struct btrfs_path extent_path;
struct btrfs_path csum_path;
int first_free;
int cur_stripe;
atomic_t cancel_req;
int readonly;
int sectors_per_bio;
/* State of IO submission throttling affecting the associated device */
ktime_t throttle_deadline;
u64 throttle_sent;
int is_dev_replace;
u64 write_pointer;
struct mutex wr_lock;
struct btrfs_device *wr_tgtdev;
/*
* statistics
*/
struct btrfs_scrub_progress stat;
spinlock_t stat_lock;
/*
* Use a ref counter to avoid use-after-free issues. Scrub workers
* decrement bios_in_flight and workers_pending and then do a wakeup
* on the list_wait wait queue. We must ensure the main scrub task
* doesn't free the scrub context before or while the workers are
* doing the wakeup() call.
*/
refcount_t refs;
};
struct scrub_warning {
struct btrfs_path *path;
u64 extent_item_size;
const char *errstr;
u64 physical;
u64 logical;
struct btrfs_device *dev;
};
static void release_scrub_stripe(struct scrub_stripe *stripe)
{
if (!stripe)
return;
for (int i = 0; i < SCRUB_STRIPE_PAGES; i++) {
if (stripe->pages[i])
__free_page(stripe->pages[i]);
stripe->pages[i] = NULL;
}
kfree(stripe->sectors);
kfree(stripe->csums);
stripe->sectors = NULL;
stripe->csums = NULL;
stripe->sctx = NULL;
stripe->state = 0;
}
static int init_scrub_stripe(struct btrfs_fs_info *fs_info,
struct scrub_stripe *stripe)
{
int ret;
memset(stripe, 0, sizeof(*stripe));
stripe->nr_sectors = BTRFS_STRIPE_LEN >> fs_info->sectorsize_bits;
stripe->state = 0;
init_waitqueue_head(&stripe->io_wait);
init_waitqueue_head(&stripe->repair_wait);
atomic_set(&stripe->pending_io, 0);
spin_lock_init(&stripe->write_error_lock);
ret = btrfs_alloc_page_array(SCRUB_STRIPE_PAGES, stripe->pages);
if (ret < 0)
goto error;
stripe->sectors = kcalloc(stripe->nr_sectors,
sizeof(struct scrub_sector_verification),
GFP_KERNEL);
if (!stripe->sectors)
goto error;
stripe->csums = kcalloc(BTRFS_STRIPE_LEN >> fs_info->sectorsize_bits,
fs_info->csum_size, GFP_KERNEL);
if (!stripe->csums)
goto error;
return 0;
error:
release_scrub_stripe(stripe);
return -ENOMEM;
}
static void wait_scrub_stripe_io(struct scrub_stripe *stripe)
{
wait_event(stripe->io_wait, atomic_read(&stripe->pending_io) == 0);
}
static void scrub_put_ctx(struct scrub_ctx *sctx);
static void __scrub_blocked_if_needed(struct btrfs_fs_info *fs_info)
{
while (atomic_read(&fs_info->scrub_pause_req)) {
mutex_unlock(&fs_info->scrub_lock);
wait_event(fs_info->scrub_pause_wait,
atomic_read(&fs_info->scrub_pause_req) == 0);
mutex_lock(&fs_info->scrub_lock);
}
}
static void scrub_pause_on(struct btrfs_fs_info *fs_info)
{
atomic_inc(&fs_info->scrubs_paused);
wake_up(&fs_info->scrub_pause_wait);
}
static void scrub_pause_off(struct btrfs_fs_info *fs_info)
{
mutex_lock(&fs_info->scrub_lock);
__scrub_blocked_if_needed(fs_info);
atomic_dec(&fs_info->scrubs_paused);
mutex_unlock(&fs_info->scrub_lock);
wake_up(&fs_info->scrub_pause_wait);
}
static void scrub_blocked_if_needed(struct btrfs_fs_info *fs_info)
{
scrub_pause_on(fs_info);
scrub_pause_off(fs_info);
}
static noinline_for_stack void scrub_free_ctx(struct scrub_ctx *sctx)
{
int i;
if (!sctx)
return;
for (i = 0; i < SCRUB_TOTAL_STRIPES; i++)
release_scrub_stripe(&sctx->stripes[i]);
kvfree(sctx);
}
static void scrub_put_ctx(struct scrub_ctx *sctx)
{
if (refcount_dec_and_test(&sctx->refs))
scrub_free_ctx(sctx);
}
static noinline_for_stack struct scrub_ctx *scrub_setup_ctx(
struct btrfs_fs_info *fs_info, int is_dev_replace)
{
struct scrub_ctx *sctx;
int i;
/* Since sctx has inline 128 stripes, it can go beyond 64K easily. Use
* kvzalloc().
*/
sctx = kvzalloc(sizeof(*sctx), GFP_KERNEL);
if (!sctx)
goto nomem;
refcount_set(&sctx->refs, 1);
sctx->is_dev_replace = is_dev_replace;
sctx->fs_info = fs_info;
sctx->extent_path.search_commit_root = 1;
sctx->extent_path.skip_locking = 1;
sctx->csum_path.search_commit_root = 1;
sctx->csum_path.skip_locking = 1;
for (i = 0; i < SCRUB_TOTAL_STRIPES; i++) {
int ret;
ret = init_scrub_stripe(fs_info, &sctx->stripes[i]);
if (ret < 0)
goto nomem;
sctx->stripes[i].sctx = sctx;
}
sctx->first_free = 0;
atomic_set(&sctx->cancel_req, 0);
spin_lock_init(&sctx->stat_lock);
sctx->throttle_deadline = 0;
mutex_init(&sctx->wr_lock);
if (is_dev_replace) {
WARN_ON(!fs_info->dev_replace.tgtdev);
sctx->wr_tgtdev = fs_info->dev_replace.tgtdev;
}
return sctx;
nomem:
scrub_free_ctx(sctx);
return ERR_PTR(-ENOMEM);
}
static int scrub_print_warning_inode(u64 inum, u64 offset, u64 num_bytes,
u64 root, void *warn_ctx)
{
u32 nlink;
int ret;
int i;
unsigned nofs_flag;
struct extent_buffer *eb;
struct btrfs_inode_item *inode_item;
struct scrub_warning *swarn = warn_ctx;
struct btrfs_fs_info *fs_info = swarn->dev->fs_info;
struct inode_fs_paths *ipath = NULL;
struct btrfs_root *local_root;
struct btrfs_key key;
local_root = btrfs_get_fs_root(fs_info, root, true);
if (IS_ERR(local_root)) {
ret = PTR_ERR(local_root);
goto err;
}
/*
* this makes the path point to (inum INODE_ITEM ioff)
*/
key.objectid = inum;
key.type = BTRFS_INODE_ITEM_KEY;
key.offset = 0;
ret = btrfs_search_slot(NULL, local_root, &key, swarn->path, 0, 0);
if (ret) {
btrfs_put_root(local_root);
btrfs_release_path(swarn->path);
goto err;
}
eb = swarn->path->nodes[0];
inode_item = btrfs_item_ptr(eb, swarn->path->slots[0],
struct btrfs_inode_item);
nlink = btrfs_inode_nlink(eb, inode_item);
btrfs_release_path(swarn->path);
/*
* init_path might indirectly call vmalloc, or use GFP_KERNEL. Scrub
* uses GFP_NOFS in this context, so we keep it consistent but it does
* not seem to be strictly necessary.
*/
nofs_flag = memalloc_nofs_save();
ipath = init_ipath(4096, local_root, swarn->path);
memalloc_nofs_restore(nofs_flag);
if (IS_ERR(ipath)) {
btrfs_put_root(local_root);
ret = PTR_ERR(ipath);
ipath = NULL;
goto err;
}
ret = paths_from_inode(inum, ipath);
if (ret < 0)
goto err;
/*
* we deliberately ignore the bit ipath might have been too small to
* hold all of the paths here
*/
for (i = 0; i < ipath->fspath->elem_cnt; ++i)
btrfs_warn_in_rcu(fs_info,
"%s at logical %llu on dev %s, physical %llu, root %llu, inode %llu, offset %llu, length %u, links %u (path: %s)",
swarn->errstr, swarn->logical,
btrfs_dev_name(swarn->dev),
swarn->physical,
root, inum, offset,
fs_info->sectorsize, nlink,
(char *)(unsigned long)ipath->fspath->val[i]);
btrfs_put_root(local_root);
free_ipath(ipath);
return 0;
err:
btrfs_warn_in_rcu(fs_info,
"%s at logical %llu on dev %s, physical %llu, root %llu, inode %llu, offset %llu: path resolving failed with ret=%d",
swarn->errstr, swarn->logical,
btrfs_dev_name(swarn->dev),
swarn->physical,
root, inum, offset, ret);
free_ipath(ipath);
return 0;
}
static void scrub_print_common_warning(const char *errstr, struct btrfs_device *dev,
bool is_super, u64 logical, u64 physical)
{
struct btrfs_fs_info *fs_info = dev->fs_info;
struct btrfs_path *path;
struct btrfs_key found_key;
struct extent_buffer *eb;
struct btrfs_extent_item *ei;
struct scrub_warning swarn;
u64 flags = 0;
u32 item_size;
int ret;
/* Super block error, no need to search extent tree. */
if (is_super) {
btrfs_warn_in_rcu(fs_info, "%s on device %s, physical %llu",
errstr, btrfs_dev_name(dev), physical);
return;
}
path = btrfs_alloc_path();
if (!path)
return;
swarn.physical = physical;
swarn.logical = logical;
swarn.errstr = errstr;
swarn.dev = NULL;
ret = extent_from_logical(fs_info, swarn.logical, path, &found_key,
&flags);
if (ret < 0)
goto out;
swarn.extent_item_size = found_key.offset;
eb = path->nodes[0];
ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item);
item_size = btrfs_item_size(eb, path->slots[0]);
if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
unsigned long ptr = 0;
u8 ref_level;
u64 ref_root;
while (true) {
ret = tree_backref_for_extent(&ptr, eb, &found_key, ei,
item_size, &ref_root,
&ref_level);
if (ret < 0) {
btrfs_warn(fs_info,
"failed to resolve tree backref for logical %llu: %d",
swarn.logical, ret);
break;
}
if (ret > 0)
break;
btrfs_warn_in_rcu(fs_info,
"%s at logical %llu on dev %s, physical %llu: metadata %s (level %d) in tree %llu",
errstr, swarn.logical, btrfs_dev_name(dev),
swarn.physical, (ref_level ? "node" : "leaf"),
ref_level, ref_root);
}
btrfs_release_path(path);
} else {
struct btrfs_backref_walk_ctx ctx = { 0 };
btrfs_release_path(path);
ctx.bytenr = found_key.objectid;
ctx.extent_item_pos = swarn.logical - found_key.objectid;
ctx.fs_info = fs_info;
swarn.path = path;
swarn.dev = dev;
iterate_extent_inodes(&ctx, true, scrub_print_warning_inode, &swarn);
}
out:
btrfs_free_path(path);
}
static int fill_writer_pointer_gap(struct scrub_ctx *sctx, u64 physical)
{
int ret = 0;
u64 length;
if (!btrfs_is_zoned(sctx->fs_info))
return 0;
if (!btrfs_dev_is_sequential(sctx->wr_tgtdev, physical))
return 0;
if (sctx->write_pointer < physical) {
length = physical - sctx->write_pointer;
ret = btrfs_zoned_issue_zeroout(sctx->wr_tgtdev,
sctx->write_pointer, length);
if (!ret)
sctx->write_pointer = physical;
}
return ret;
}
static struct page *scrub_stripe_get_page(struct scrub_stripe *stripe, int sector_nr)
{
struct btrfs_fs_info *fs_info = stripe->bg->fs_info;
int page_index = (sector_nr << fs_info->sectorsize_bits) >> PAGE_SHIFT;
return stripe->pages[page_index];
}
static unsigned int scrub_stripe_get_page_offset(struct scrub_stripe *stripe,
int sector_nr)
{
struct btrfs_fs_info *fs_info = stripe->bg->fs_info;
return offset_in_page(sector_nr << fs_info->sectorsize_bits);
}
static void scrub_verify_one_metadata(struct scrub_stripe *stripe, int sector_nr)
{
struct btrfs_fs_info *fs_info = stripe->bg->fs_info;
const u32 sectors_per_tree = fs_info->nodesize >> fs_info->sectorsize_bits;
const u64 logical = stripe->logical + (sector_nr << fs_info->sectorsize_bits);
const struct page *first_page = scrub_stripe_get_page(stripe, sector_nr);
const unsigned int first_off = scrub_stripe_get_page_offset(stripe, sector_nr);
SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
u8 on_disk_csum[BTRFS_CSUM_SIZE];
u8 calculated_csum[BTRFS_CSUM_SIZE];
struct btrfs_header *header;
/*
* Here we don't have a good way to attach the pages (and subpages)
* to a dummy extent buffer, thus we have to directly grab the members
* from pages.
*/
header = (struct btrfs_header *)(page_address(first_page) + first_off);
memcpy(on_disk_csum, header->csum, fs_info->csum_size);
if (logical != btrfs_stack_header_bytenr(header)) {
bitmap_set(&stripe->csum_error_bitmap, sector_nr, sectors_per_tree);
bitmap_set(&stripe->error_bitmap, sector_nr, sectors_per_tree);
btrfs_warn_rl(fs_info,
"tree block %llu mirror %u has bad bytenr, has %llu want %llu",
logical, stripe->mirror_num,
btrfs_stack_header_bytenr(header), logical);
return;
}
if (memcmp(header->fsid, fs_info->fs_devices->metadata_uuid,
BTRFS_FSID_SIZE) != 0) {
bitmap_set(&stripe->meta_error_bitmap, sector_nr, sectors_per_tree);
bitmap_set(&stripe->error_bitmap, sector_nr, sectors_per_tree);
btrfs_warn_rl(fs_info,
"tree block %llu mirror %u has bad fsid, has %pU want %pU",
logical, stripe->mirror_num,
header->fsid, fs_info->fs_devices->fsid);
return;
}
if (memcmp(header->chunk_tree_uuid, fs_info->chunk_tree_uuid,
BTRFS_UUID_SIZE) != 0) {
bitmap_set(&stripe->meta_error_bitmap, sector_nr, sectors_per_tree);
bitmap_set(&stripe->error_bitmap, sector_nr, sectors_per_tree);
btrfs_warn_rl(fs_info,
"tree block %llu mirror %u has bad chunk tree uuid, has %pU want %pU",
logical, stripe->mirror_num,
header->chunk_tree_uuid, fs_info->chunk_tree_uuid);
return;
}
/* Now check tree block csum. */
shash->tfm = fs_info->csum_shash;
crypto_shash_init(shash);
crypto_shash_update(shash, page_address(first_page) + first_off +
BTRFS_CSUM_SIZE, fs_info->sectorsize - BTRFS_CSUM_SIZE);
for (int i = sector_nr + 1; i < sector_nr + sectors_per_tree; i++) {
struct page *page = scrub_stripe_get_page(stripe, i);
unsigned int page_off = scrub_stripe_get_page_offset(stripe, i);
crypto_shash_update(shash, page_address(page) + page_off,
fs_info->sectorsize);
}
crypto_shash_final(shash, calculated_csum);
if (memcmp(calculated_csum, on_disk_csum, fs_info->csum_size) != 0) {
bitmap_set(&stripe->meta_error_bitmap, sector_nr, sectors_per_tree);
bitmap_set(&stripe->error_bitmap, sector_nr, sectors_per_tree);
btrfs_warn_rl(fs_info,
"tree block %llu mirror %u has bad csum, has " CSUM_FMT " want " CSUM_FMT,
logical, stripe->mirror_num,
CSUM_FMT_VALUE(fs_info->csum_size, on_disk_csum),
CSUM_FMT_VALUE(fs_info->csum_size, calculated_csum));
return;
}
if (stripe->sectors[sector_nr].generation !=
btrfs_stack_header_generation(header)) {
bitmap_set(&stripe->meta_error_bitmap, sector_nr, sectors_per_tree);
bitmap_set(&stripe->error_bitmap, sector_nr, sectors_per_tree);
btrfs_warn_rl(fs_info,
"tree block %llu mirror %u has bad generation, has %llu want %llu",
logical, stripe->mirror_num,
btrfs_stack_header_generation(header),
stripe->sectors[sector_nr].generation);
return;
}
bitmap_clear(&stripe->error_bitmap, sector_nr, sectors_per_tree);
bitmap_clear(&stripe->csum_error_bitmap, sector_nr, sectors_per_tree);
bitmap_clear(&stripe->meta_error_bitmap, sector_nr, sectors_per_tree);
}
static void scrub_verify_one_sector(struct scrub_stripe *stripe, int sector_nr)
{
struct btrfs_fs_info *fs_info = stripe->bg->fs_info;
struct scrub_sector_verification *sector = &stripe->sectors[sector_nr];
const u32 sectors_per_tree = fs_info->nodesize >> fs_info->sectorsize_bits;
struct page *page = scrub_stripe_get_page(stripe, sector_nr);
unsigned int pgoff = scrub_stripe_get_page_offset(stripe, sector_nr);
u8 csum_buf[BTRFS_CSUM_SIZE];
int ret;
ASSERT(sector_nr >= 0 && sector_nr < stripe->nr_sectors);
/* Sector not utilized, skip it. */
if (!test_bit(sector_nr, &stripe->extent_sector_bitmap))
return;
/* IO error, no need to check. */
if (test_bit(sector_nr, &stripe->io_error_bitmap))
return;
/* Metadata, verify the full tree block. */
if (sector->is_metadata) {
/*
* Check if the tree block crosses the stripe boudary. If
* crossed the boundary, we cannot verify it but only give a
* warning.
*
* This can only happen on a very old filesystem where chunks
* are not ensured to be stripe aligned.
*/
if (unlikely(sector_nr + sectors_per_tree > stripe->nr_sectors)) {
btrfs_warn_rl(fs_info,
"tree block at %llu crosses stripe boundary %llu",
stripe->logical +
(sector_nr << fs_info->sectorsize_bits),
stripe->logical);
return;
}
scrub_verify_one_metadata(stripe, sector_nr);
return;
}
/*
* Data is easier, we just verify the data csum (if we have it). For
* cases without csum, we have no other choice but to trust it.
*/
if (!sector->csum) {
clear_bit(sector_nr, &stripe->error_bitmap);
return;
}
ret = btrfs_check_sector_csum(fs_info, page, pgoff, csum_buf, sector->csum);
if (ret < 0) {
set_bit(sector_nr, &stripe->csum_error_bitmap);
set_bit(sector_nr, &stripe->error_bitmap);
} else {
clear_bit(sector_nr, &stripe->csum_error_bitmap);
clear_bit(sector_nr, &stripe->error_bitmap);
}
}
/* Verify specified sectors of a stripe. */
static void scrub_verify_one_stripe(struct scrub_stripe *stripe, unsigned long bitmap)
{
struct btrfs_fs_info *fs_info = stripe->bg->fs_info;
const u32 sectors_per_tree = fs_info->nodesize >> fs_info->sectorsize_bits;
int sector_nr;
for_each_set_bit(sector_nr, &bitmap, stripe->nr_sectors) {
scrub_verify_one_sector(stripe, sector_nr);
if (stripe->sectors[sector_nr].is_metadata)
sector_nr += sectors_per_tree - 1;
}
}
static int calc_sector_number(struct scrub_stripe *stripe, struct bio_vec *first_bvec)
{
int i;
for (i = 0; i < stripe->nr_sectors; i++) {
if (scrub_stripe_get_page(stripe, i) == first_bvec->bv_page &&
scrub_stripe_get_page_offset(stripe, i) == first_bvec->bv_offset)
break;
}
ASSERT(i < stripe->nr_sectors);
return i;
}
/*
* Repair read is different to the regular read:
*
* - Only reads the failed sectors
* - May have extra blocksize limits
*/
static void scrub_repair_read_endio(struct btrfs_bio *bbio)
{
struct scrub_stripe *stripe = bbio->private;
struct btrfs_fs_info *fs_info = stripe->bg->fs_info;
struct bio_vec *bvec;
int sector_nr = calc_sector_number(stripe, bio_first_bvec_all(&bbio->bio));
u32 bio_size = 0;
int i;
ASSERT(sector_nr < stripe->nr_sectors);
bio_for_each_bvec_all(bvec, &bbio->bio, i)
bio_size += bvec->bv_len;
if (bbio->bio.bi_status) {
bitmap_set(&stripe->io_error_bitmap, sector_nr,
bio_size >> fs_info->sectorsize_bits);
bitmap_set(&stripe->error_bitmap, sector_nr,
bio_size >> fs_info->sectorsize_bits);
} else {
bitmap_clear(&stripe->io_error_bitmap, sector_nr,
bio_size >> fs_info->sectorsize_bits);
}
bio_put(&bbio->bio);
if (atomic_dec_and_test(&stripe->pending_io))
wake_up(&stripe->io_wait);
}
static int calc_next_mirror(int mirror, int num_copies)
{
ASSERT(mirror <= num_copies);
return (mirror + 1 > num_copies) ? 1 : mirror + 1;
}
static void scrub_stripe_submit_repair_read(struct scrub_stripe *stripe,
int mirror, int blocksize, bool wait)
{
struct btrfs_fs_info *fs_info = stripe->bg->fs_info;
struct btrfs_bio *bbio = NULL;
const unsigned long old_error_bitmap = stripe->error_bitmap;
int i;
ASSERT(stripe->mirror_num >= 1);
ASSERT(atomic_read(&stripe->pending_io) == 0);
for_each_set_bit(i, &old_error_bitmap, stripe->nr_sectors) {
struct page *page;
int pgoff;
int ret;
page = scrub_stripe_get_page(stripe, i);
pgoff = scrub_stripe_get_page_offset(stripe, i);
/* The current sector cannot be merged, submit the bio. */
if (bbio && ((i > 0 && !test_bit(i - 1, &stripe->error_bitmap)) ||
bbio->bio.bi_iter.bi_size >= blocksize)) {
ASSERT(bbio->bio.bi_iter.bi_size);
atomic_inc(&stripe->pending_io);
btrfs_submit_bio(bbio, mirror);
if (wait)
wait_scrub_stripe_io(stripe);
bbio = NULL;
}
if (!bbio) {
bbio = btrfs_bio_alloc(stripe->nr_sectors, REQ_OP_READ,
fs_info, scrub_repair_read_endio, stripe);
bbio->bio.bi_iter.bi_sector = (stripe->logical +
(i << fs_info->sectorsize_bits)) >> SECTOR_SHIFT;
}
ret = bio_add_page(&bbio->bio, page, fs_info->sectorsize, pgoff);
ASSERT(ret == fs_info->sectorsize);
}
if (bbio) {
ASSERT(bbio->bio.bi_iter.bi_size);
atomic_inc(&stripe->pending_io);
btrfs_submit_bio(bbio, mirror);
if (wait)
wait_scrub_stripe_io(stripe);
}
}
static void scrub_stripe_report_errors(struct scrub_ctx *sctx,
struct scrub_stripe *stripe)
{
static DEFINE_RATELIMIT_STATE(rs, DEFAULT_RATELIMIT_INTERVAL,
DEFAULT_RATELIMIT_BURST);
struct btrfs_fs_info *fs_info = sctx->fs_info;
struct btrfs_device *dev = NULL;
u64 physical = 0;
int nr_data_sectors = 0;
int nr_meta_sectors = 0;
int nr_nodatacsum_sectors = 0;
int nr_repaired_sectors = 0;
int sector_nr;
if (test_bit(SCRUB_STRIPE_FLAG_NO_REPORT, &stripe->state))
return;
/*
* Init needed infos for error reporting.
*
* Although our scrub_stripe infrastucture is mostly based on btrfs_submit_bio()
* thus no need for dev/physical, error reporting still needs dev and physical.
*/
if (!bitmap_empty(&stripe->init_error_bitmap, stripe->nr_sectors)) {
u64 mapped_len = fs_info->sectorsize;
struct btrfs_io_context *bioc = NULL;
int stripe_index = stripe->mirror_num - 1;
int ret;
/* For scrub, our mirror_num should always start at 1. */
ASSERT(stripe->mirror_num >= 1);
ret = btrfs_map_block(fs_info, BTRFS_MAP_GET_READ_MIRRORS,
stripe->logical, &mapped_len, &bioc,
NULL, NULL);
/*
* If we failed, dev will be NULL, and later detailed reports
* will just be skipped.
*/
if (ret < 0)
goto skip;
physical = bioc->stripes[stripe_index].physical;
dev = bioc->stripes[stripe_index].dev;
btrfs_put_bioc(bioc);
}
skip:
for_each_set_bit(sector_nr, &stripe->extent_sector_bitmap, stripe->nr_sectors) {
bool repaired = false;
if (stripe->sectors[sector_nr].is_metadata) {
nr_meta_sectors++;
} else {
nr_data_sectors++;
if (!stripe->sectors[sector_nr].csum)
nr_nodatacsum_sectors++;
}
if (test_bit(sector_nr, &stripe->init_error_bitmap) &&
!test_bit(sector_nr, &stripe->error_bitmap)) {
nr_repaired_sectors++;
repaired = true;
}
/* Good sector from the beginning, nothing need to be done. */
if (!test_bit(sector_nr, &stripe->init_error_bitmap))
continue;
/*
* Report error for the corrupted sectors. If repaired, just
* output the message of repaired message.
*/
if (repaired) {
if (dev) {
btrfs_err_rl_in_rcu(fs_info,
"fixed up error at logical %llu on dev %s physical %llu",
stripe->logical, btrfs_dev_name(dev),
physical);
} else {
btrfs_err_rl_in_rcu(fs_info,
"fixed up error at logical %llu on mirror %u",
stripe->logical, stripe->mirror_num);
}
continue;
}
/* The remaining are all for unrepaired. */
if (dev) {
btrfs_err_rl_in_rcu(fs_info,
"unable to fixup (regular) error at logical %llu on dev %s physical %llu",
stripe->logical, btrfs_dev_name(dev),
physical);
} else {
btrfs_err_rl_in_rcu(fs_info,
"unable to fixup (regular) error at logical %llu on mirror %u",
stripe->logical, stripe->mirror_num);
}
if (test_bit(sector_nr, &stripe->io_error_bitmap))
if (__ratelimit(&rs) && dev)
scrub_print_common_warning("i/o error", dev, false,
stripe->logical, physical);
if (test_bit(sector_nr, &stripe->csum_error_bitmap))
if (__ratelimit(&rs) && dev)
scrub_print_common_warning("checksum error", dev, false,
stripe->logical, physical);
if (test_bit(sector_nr, &stripe->meta_error_bitmap))
if (__ratelimit(&rs) && dev)
scrub_print_common_warning("header error", dev, false,
stripe->logical, physical);
}
spin_lock(&sctx->stat_lock);
sctx->stat.data_extents_scrubbed += stripe->nr_data_extents;
sctx->stat.tree_extents_scrubbed += stripe->nr_meta_extents;
sctx->stat.data_bytes_scrubbed += nr_data_sectors << fs_info->sectorsize_bits;
sctx->stat.tree_bytes_scrubbed += nr_meta_sectors << fs_info->sectorsize_bits;
sctx->stat.no_csum += nr_nodatacsum_sectors;
sctx->stat.read_errors += stripe->init_nr_io_errors;
sctx->stat.csum_errors += stripe->init_nr_csum_errors;
sctx->stat.verify_errors += stripe->init_nr_meta_errors;
sctx->stat.uncorrectable_errors +=
bitmap_weight(&stripe->error_bitmap, stripe->nr_sectors);
sctx->stat.corrected_errors += nr_repaired_sectors;
spin_unlock(&sctx->stat_lock);
}
static void scrub_write_sectors(struct scrub_ctx *sctx, struct scrub_stripe *stripe,
unsigned long write_bitmap, bool dev_replace);
/*
* The main entrance for all read related scrub work, including:
*
* - Wait for the initial read to finish
* - Verify and locate any bad sectors
* - Go through the remaining mirrors and try to read as large blocksize as
* possible
* - Go through all mirrors (including the failed mirror) sector-by-sector
* - Submit writeback for repaired sectors
*
* Writeback for dev-replace does not happen here, it needs extra
* synchronization for zoned devices.
*/
static void scrub_stripe_read_repair_worker(struct work_struct *work)
{
struct scrub_stripe *stripe = container_of(work, struct scrub_stripe, work);
struct scrub_ctx *sctx = stripe->sctx;
struct btrfs_fs_info *fs_info = sctx->fs_info;
int num_copies = btrfs_num_copies(fs_info, stripe->bg->start,
stripe->bg->length);
int mirror;
int i;
ASSERT(stripe->mirror_num > 0);
wait_scrub_stripe_io(stripe);
scrub_verify_one_stripe(stripe, stripe->extent_sector_bitmap);
/* Save the initial failed bitmap for later repair and report usage. */
stripe->init_error_bitmap = stripe->error_bitmap;
stripe->init_nr_io_errors = bitmap_weight(&stripe->io_error_bitmap,
stripe->nr_sectors);
stripe->init_nr_csum_errors = bitmap_weight(&stripe->csum_error_bitmap,
stripe->nr_sectors);
stripe->init_nr_meta_errors = bitmap_weight(&stripe->meta_error_bitmap,
stripe->nr_sectors);
if (bitmap_empty(&stripe->init_error_bitmap, stripe->nr_sectors))
goto out;
/*
* Try all remaining mirrors.
*
* Here we still try to read as large block as possible, as this is
* faster and we have extra safety nets to rely on.
*/
for (mirror = calc_next_mirror(stripe->mirror_num, num_copies);
mirror != stripe->mirror_num;
mirror = calc_next_mirror(mirror, num_copies)) {
const unsigned long old_error_bitmap = stripe->error_bitmap;
scrub_stripe_submit_repair_read(stripe, mirror,
BTRFS_STRIPE_LEN, false);
wait_scrub_stripe_io(stripe);
scrub_verify_one_stripe(stripe, old_error_bitmap);
if (bitmap_empty(&stripe->error_bitmap, stripe->nr_sectors))
goto out;
}
/*
* Last safety net, try re-checking all mirrors, including the failed
* one, sector-by-sector.
*
* As if one sector failed the drive's internal csum, the whole read
* containing the offending sector would be marked as error.
* Thus here we do sector-by-sector read.
*
* This can be slow, thus we only try it as the last resort.
*/
for (i = 0, mirror = stripe->mirror_num;
i < num_copies;
i++, mirror = calc_next_mirror(mirror, num_copies)) {
const unsigned long old_error_bitmap = stripe->error_bitmap;
scrub_stripe_submit_repair_read(stripe, mirror,
fs_info->sectorsize, true);
wait_scrub_stripe_io(stripe);
scrub_verify_one_stripe(stripe, old_error_bitmap);
if (bitmap_empty(&stripe->error_bitmap, stripe->nr_sectors))
goto out;
}
out:
/*
* Submit the repaired sectors. For zoned case, we cannot do repair
* in-place, but queue the bg to be relocated.
*/
if (btrfs_is_zoned(fs_info)) {
if (!bitmap_empty(&stripe->error_bitmap, stripe->nr_sectors))
btrfs_repair_one_zone(fs_info, sctx->stripes[0].bg->start);
} else if (!sctx->readonly) {
unsigned long repaired;
bitmap_andnot(&repaired, &stripe->init_error_bitmap,
&stripe->error_bitmap, stripe->nr_sectors);
scrub_write_sectors(sctx, stripe, repaired, false);
wait_scrub_stripe_io(stripe);
}
scrub_stripe_report_errors(sctx, stripe);
set_bit(SCRUB_STRIPE_FLAG_REPAIR_DONE, &stripe->state);
wake_up(&stripe->repair_wait);
}
static void scrub_read_endio(struct btrfs_bio *bbio)
{
struct scrub_stripe *stripe = bbio->private;
if (bbio->bio.bi_status) {
bitmap_set(&stripe->io_error_bitmap, 0, stripe->nr_sectors);
bitmap_set(&stripe->error_bitmap, 0, stripe->nr_sectors);
} else {
bitmap_clear(&stripe->io_error_bitmap, 0, stripe->nr_sectors);
}
bio_put(&bbio->bio);
if (atomic_dec_and_test(&stripe->pending_io)) {
wake_up(&stripe->io_wait);
INIT_WORK(&stripe->work, scrub_stripe_read_repair_worker);
queue_work(stripe->bg->fs_info->scrub_workers, &stripe->work);
}
}
static void scrub_write_endio(struct btrfs_bio *bbio)
{
struct scrub_stripe *stripe = bbio->private;
struct btrfs_fs_info *fs_info = stripe->bg->fs_info;
struct bio_vec *bvec;
int sector_nr = calc_sector_number(stripe, bio_first_bvec_all(&bbio->bio));
u32 bio_size = 0;
int i;
bio_for_each_bvec_all(bvec, &bbio->bio, i)
bio_size += bvec->bv_len;
if (bbio->bio.bi_status) {
unsigned long flags;
spin_lock_irqsave(&stripe->write_error_lock, flags);
bitmap_set(&stripe->write_error_bitmap, sector_nr,
bio_size >> fs_info->sectorsize_bits);
spin_unlock_irqrestore(&stripe->write_error_lock, flags);
}
bio_put(&bbio->bio);
if (atomic_dec_and_test(&stripe->pending_io))
wake_up(&stripe->io_wait);
}
static void scrub_submit_write_bio(struct scrub_ctx *sctx,
struct scrub_stripe *stripe,
struct btrfs_bio *bbio, bool dev_replace)
{
struct btrfs_fs_info *fs_info = sctx->fs_info;
u32 bio_len = bbio->bio.bi_iter.bi_size;
u32 bio_off = (bbio->bio.bi_iter.bi_sector << SECTOR_SHIFT) -
stripe->logical;
fill_writer_pointer_gap(sctx, stripe->physical + bio_off);
atomic_inc(&stripe->pending_io);
btrfs_submit_repair_write(bbio, stripe->mirror_num, dev_replace);
if (!btrfs_is_zoned(fs_info))
return;
/*
* For zoned writeback, queue depth must be 1, thus we must wait for
* the write to finish before the next write.
*/
wait_scrub_stripe_io(stripe);
/*
* And also need to update the write pointer if write finished
* successfully.
*/
if (!test_bit(bio_off >> fs_info->sectorsize_bits,
&stripe->write_error_bitmap))
sctx->write_pointer += bio_len;
}
/*
* Submit the write bio(s) for the sectors specified by @write_bitmap.
*
* Here we utilize btrfs_submit_repair_write(), which has some extra benefits:
*
* - Only needs logical bytenr and mirror_num
* Just like the scrub read path
*
* - Would only result in writes to the specified mirror
* Unlike the regular writeback path, which would write back to all stripes
*
* - Handle dev-replace and read-repair writeback differently
*/
static void scrub_write_sectors(struct scrub_ctx *sctx, struct scrub_stripe *stripe,
unsigned long write_bitmap, bool dev_replace)
{
struct btrfs_fs_info *fs_info = stripe->bg->fs_info;
struct btrfs_bio *bbio = NULL;
int sector_nr;
for_each_set_bit(sector_nr, &write_bitmap, stripe->nr_sectors) {
struct page *page = scrub_stripe_get_page(stripe, sector_nr);
unsigned int pgoff = scrub_stripe_get_page_offset(stripe, sector_nr);
int ret;
/* We should only writeback sectors covered by an extent. */
ASSERT(test_bit(sector_nr, &stripe->extent_sector_bitmap));
/* Cannot merge with previous sector, submit the current one. */
if (bbio && sector_nr && !test_bit(sector_nr - 1, &write_bitmap)) {
scrub_submit_write_bio(sctx, stripe, bbio, dev_replace);
bbio = NULL;
}
if (!bbio) {
bbio = btrfs_bio_alloc(stripe->nr_sectors, REQ_OP_WRITE,
fs_info, scrub_write_endio, stripe);
bbio->bio.bi_iter.bi_sector = (stripe->logical +
(sector_nr << fs_info->sectorsize_bits)) >>
SECTOR_SHIFT;
}
ret = bio_add_page(&bbio->bio, page, fs_info->sectorsize, pgoff);
ASSERT(ret == fs_info->sectorsize);
}
if (bbio)
scrub_submit_write_bio(sctx, stripe, bbio, dev_replace);
}
/*
* Throttling of IO submission, bandwidth-limit based, the timeslice is 1
* second. Limit can be set via /sys/fs/UUID/devinfo/devid/scrub_speed_max.
*/
static void scrub_throttle_dev_io(struct scrub_ctx *sctx, struct btrfs_device *device,
unsigned int bio_size)
{
const int time_slice = 1000;
s64 delta;
ktime_t now;
u32 div;
u64 bwlimit;
bwlimit = READ_ONCE(device->scrub_speed_max);
if (bwlimit == 0)
return;
/*
* Slice is divided into intervals when the IO is submitted, adjust by
* bwlimit and maximum of 64 intervals.
*/
div = max_t(u32, 1, (u32)(bwlimit / (16 * 1024 * 1024)));
div = min_t(u32, 64, div);
/* Start new epoch, set deadline */
now = ktime_get();
if (sctx->throttle_deadline == 0) {
sctx->throttle_deadline = ktime_add_ms(now, time_slice / div);
sctx->throttle_sent = 0;
}
/* Still in the time to send? */
if (ktime_before(now, sctx->throttle_deadline)) {
/* If current bio is within the limit, send it */
sctx->throttle_sent += bio_size;
if (sctx->throttle_sent <= div_u64(bwlimit, div))
return;
/* We're over the limit, sleep until the rest of the slice */
delta = ktime_ms_delta(sctx->throttle_deadline, now);
} else {
/* New request after deadline, start new epoch */
delta = 0;
}
if (delta) {
long timeout;
timeout = div_u64(delta * HZ, 1000);
schedule_timeout_interruptible(timeout);
}
/* Next call will start the deadline period */
sctx->throttle_deadline = 0;
}
/*
* Given a physical address, this will calculate it's
* logical offset. if this is a parity stripe, it will return
* the most left data stripe's logical offset.
*
* return 0 if it is a data stripe, 1 means parity stripe.
*/
static int get_raid56_logic_offset(u64 physical, int num,
struct map_lookup *map, u64 *offset,
u64 *stripe_start)
{
int i;
int j = 0;
u64 last_offset;
const int data_stripes = nr_data_stripes(map);
last_offset = (physical - map->stripes[num].physical) * data_stripes;
if (stripe_start)
*stripe_start = last_offset;
*offset = last_offset;
for (i = 0; i < data_stripes; i++) {
u32 stripe_nr;
u32 stripe_index;
u32 rot;
*offset = last_offset + btrfs_stripe_nr_to_offset(i);
stripe_nr = (u32)(*offset >> BTRFS_STRIPE_LEN_SHIFT) / data_stripes;
/* Work out the disk rotation on this stripe-set */
rot = stripe_nr % map->num_stripes;
/* calculate which stripe this data locates */
rot += i;
stripe_index = rot % map->num_stripes;
if (stripe_index == num)
return 0;
if (stripe_index < num)
j++;
}
*offset = last_offset + btrfs_stripe_nr_to_offset(j);
return 1;
}
/*
* Return 0 if the extent item range covers any byte of the range.
* Return <0 if the extent item is before @search_start.
* Return >0 if the extent item is after @start_start + @search_len.
*/
static int compare_extent_item_range(struct btrfs_path *path,
u64 search_start, u64 search_len)
{
struct btrfs_fs_info *fs_info = path->nodes[0]->fs_info;
u64 len;
struct btrfs_key key;
btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
ASSERT(key.type == BTRFS_EXTENT_ITEM_KEY ||
key.type == BTRFS_METADATA_ITEM_KEY);
if (key.type == BTRFS_METADATA_ITEM_KEY)
len = fs_info->nodesize;
else
len = key.offset;
if (key.objectid + len <= search_start)
return -1;
if (key.objectid >= search_start + search_len)
return 1;
return 0;
}
/*
* Locate one extent item which covers any byte in range
* [@search_start, @search_start + @search_length)
*
* If the path is not initialized, we will initialize the search by doing
* a btrfs_search_slot().
* If the path is already initialized, we will use the path as the initial
* slot, to avoid duplicated btrfs_search_slot() calls.
*
* NOTE: If an extent item starts before @search_start, we will still
* return the extent item. This is for data extent crossing stripe boundary.
*
* Return 0 if we found such extent item, and @path will point to the extent item.
* Return >0 if no such extent item can be found, and @path will be released.
* Return <0 if hit fatal error, and @path will be released.
*/
static int find_first_extent_item(struct btrfs_root *extent_root,
struct btrfs_path *path,
u64 search_start, u64 search_len)
{
struct btrfs_fs_info *fs_info = extent_root->fs_info;
struct btrfs_key key;
int ret;
/* Continue using the existing path */
if (path->nodes[0])
goto search_forward;
if (btrfs_fs_incompat(fs_info, SKINNY_METADATA))
key.type = BTRFS_METADATA_ITEM_KEY;
else
key.type = BTRFS_EXTENT_ITEM_KEY;
key.objectid = search_start;
key.offset = (u64)-1;
ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
if (ret < 0)
return ret;
ASSERT(ret > 0);
/*
* Here we intentionally pass 0 as @min_objectid, as there could be
* an extent item starting before @search_start.
*/
ret = btrfs_previous_extent_item(extent_root, path, 0);
if (ret < 0)
return ret;
/*
* No matter whether we have found an extent item, the next loop will
* properly do every check on the key.
*/
search_forward:
while (true) {
btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
if (key.objectid >= search_start + search_len)
break;
if (key.type != BTRFS_METADATA_ITEM_KEY &&
key.type != BTRFS_EXTENT_ITEM_KEY)
goto next;
ret = compare_extent_item_range(path, search_start, search_len);
if (ret == 0)
return ret;
if (ret > 0)
break;
next:
path->slots[0]++;
if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
ret = btrfs_next_leaf(extent_root, path);
if (ret) {
/* Either no more item or fatal error */
btrfs_release_path(path);
return ret;
}
}
}
btrfs_release_path(path);
return 1;
}
static void get_extent_info(struct btrfs_path *path, u64 *extent_start_ret,
u64 *size_ret, u64 *flags_ret, u64 *generation_ret)
{
struct btrfs_key key;
struct btrfs_extent_item *ei;
btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
ASSERT(key.type == BTRFS_METADATA_ITEM_KEY ||
key.type == BTRFS_EXTENT_ITEM_KEY);
*extent_start_ret = key.objectid;
if (key.type == BTRFS_METADATA_ITEM_KEY)
*size_ret = path->nodes[0]->fs_info->nodesize;
else
*size_ret = key.offset;
ei = btrfs_item_ptr(path->nodes[0], path->slots[0], struct btrfs_extent_item);
*flags_ret = btrfs_extent_flags(path->nodes[0], ei);
*generation_ret = btrfs_extent_generation(path->nodes[0], ei);
}
static int sync_write_pointer_for_zoned(struct scrub_ctx *sctx, u64 logical,
u64 physical, u64 physical_end)
{
struct btrfs_fs_info *fs_info = sctx->fs_info;
int ret = 0;
if (!btrfs_is_zoned(fs_info))
return 0;
mutex_lock(&sctx->wr_lock);
if (sctx->write_pointer < physical_end) {
ret = btrfs_sync_zone_write_pointer(sctx->wr_tgtdev, logical,
physical,
sctx->write_pointer);
if (ret)
btrfs_err(fs_info,
"zoned: failed to recover write pointer");
}
mutex_unlock(&sctx->wr_lock);
btrfs_dev_clear_zone_empty(sctx->wr_tgtdev, physical);
return ret;
}
static void fill_one_extent_info(struct btrfs_fs_info *fs_info,
struct scrub_stripe *stripe,
u64 extent_start, u64 extent_len,
u64 extent_flags, u64 extent_gen)
{
for (u64 cur_logical = max(stripe->logical, extent_start);
cur_logical < min(stripe->logical + BTRFS_STRIPE_LEN,
extent_start + extent_len);
cur_logical += fs_info->sectorsize) {
const int nr_sector = (cur_logical - stripe->logical) >>
fs_info->sectorsize_bits;
struct scrub_sector_verification *sector =
&stripe->sectors[nr_sector];
set_bit(nr_sector, &stripe->extent_sector_bitmap);
if (extent_flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
sector->is_metadata = true;
sector->generation = extent_gen;
}
}
}
static void scrub_stripe_reset_bitmaps(struct scrub_stripe *stripe)
{
stripe->extent_sector_bitmap = 0;
stripe->init_error_bitmap = 0;
stripe->init_nr_io_errors = 0;
stripe->init_nr_csum_errors = 0;
stripe->init_nr_meta_errors = 0;
stripe->error_bitmap = 0;
stripe->io_error_bitmap = 0;
stripe->csum_error_bitmap = 0;
stripe->meta_error_bitmap = 0;
}
/*
* Locate one stripe which has at least one extent in its range.
*
* Return 0 if found such stripe, and store its info into @stripe.
* Return >0 if there is no such stripe in the specified range.
* Return <0 for error.
*/
static int scrub_find_fill_first_stripe(struct btrfs_block_group *bg,
struct btrfs_path *extent_path,
struct btrfs_path *csum_path,
struct btrfs_device *dev, u64 physical,
int mirror_num, u64 logical_start,
u32 logical_len,
struct scrub_stripe *stripe)
{
struct btrfs_fs_info *fs_info = bg->fs_info;
struct btrfs_root *extent_root = btrfs_extent_root(fs_info, bg->start);
struct btrfs_root *csum_root = btrfs_csum_root(fs_info, bg->start);
const u64 logical_end = logical_start + logical_len;
u64 cur_logical = logical_start;
u64 stripe_end;
u64 extent_start;
u64 extent_len;
u64 extent_flags;
u64 extent_gen;
int ret;
memset(stripe->sectors, 0, sizeof(struct scrub_sector_verification) *
stripe->nr_sectors);
scrub_stripe_reset_bitmaps(stripe);
/* The range must be inside the bg. */
ASSERT(logical_start >= bg->start && logical_end <= bg->start + bg->length);
ret = find_first_extent_item(extent_root, extent_path, logical_start,
logical_len);
/* Either error or not found. */
if (ret)
goto out;
get_extent_info(extent_path, &extent_start, &extent_len, &extent_flags,
&extent_gen);
if (extent_flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)
stripe->nr_meta_extents++;
if (extent_flags & BTRFS_EXTENT_FLAG_DATA)
stripe->nr_data_extents++;
cur_logical = max(extent_start, cur_logical);
/*
* Round down to stripe boundary.
*
* The extra calculation against bg->start is to handle block groups
* whose logical bytenr is not BTRFS_STRIPE_LEN aligned.
*/
stripe->logical = round_down(cur_logical - bg->start, BTRFS_STRIPE_LEN) +
bg->start;
stripe->physical = physical + stripe->logical - logical_start;
stripe->dev = dev;
stripe->bg = bg;
stripe->mirror_num = mirror_num;
stripe_end = stripe->logical + BTRFS_STRIPE_LEN - 1;
/* Fill the first extent info into stripe->sectors[] array. */
fill_one_extent_info(fs_info, stripe, extent_start, extent_len,
extent_flags, extent_gen);
cur_logical = extent_start + extent_len;
/* Fill the extent info for the remaining sectors. */
while (cur_logical <= stripe_end) {
ret = find_first_extent_item(extent_root, extent_path, cur_logical,
stripe_end - cur_logical + 1);
if (ret < 0)
goto out;
if (ret > 0) {
ret = 0;
break;
}
get_extent_info(extent_path, &extent_start, &extent_len,
&extent_flags, &extent_gen);
if (extent_flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)
stripe->nr_meta_extents++;
if (extent_flags & BTRFS_EXTENT_FLAG_DATA)
stripe->nr_data_extents++;
fill_one_extent_info(fs_info, stripe, extent_start, extent_len,
extent_flags, extent_gen);
cur_logical = extent_start + extent_len;
}
/* Now fill the data csum. */
if (bg->flags & BTRFS_BLOCK_GROUP_DATA) {
int sector_nr;
unsigned long csum_bitmap = 0;
/* Csum space should have already been allocated. */
ASSERT(stripe->csums);
/*
* Our csum bitmap should be large enough, as BTRFS_STRIPE_LEN
* should contain at most 16 sectors.
*/
ASSERT(BITS_PER_LONG >= BTRFS_STRIPE_LEN >> fs_info->sectorsize_bits);
ret = btrfs_lookup_csums_bitmap(csum_root, csum_path,
stripe->logical, stripe_end,
stripe->csums, &csum_bitmap);
if (ret < 0)
goto out;
if (ret > 0)
ret = 0;
for_each_set_bit(sector_nr, &csum_bitmap, stripe->nr_sectors) {
stripe->sectors[sector_nr].csum = stripe->csums +
sector_nr * fs_info->csum_size;
}
}
set_bit(SCRUB_STRIPE_FLAG_INITIALIZED, &stripe->state);
out:
return ret;
}
static void scrub_reset_stripe(struct scrub_stripe *stripe)
{
scrub_stripe_reset_bitmaps(stripe);
stripe->nr_meta_extents = 0;
stripe->nr_data_extents = 0;
stripe->state = 0;
for (int i = 0; i < stripe->nr_sectors; i++) {
stripe->sectors[i].is_metadata = false;
stripe->sectors[i].csum = NULL;
stripe->sectors[i].generation = 0;
}
}
static void scrub_submit_extent_sector_read(struct scrub_ctx *sctx,
struct scrub_stripe *stripe)
{
struct btrfs_fs_info *fs_info = stripe->bg->fs_info;
struct btrfs_bio *bbio = NULL;
u64 stripe_len = BTRFS_STRIPE_LEN;
int mirror = stripe->mirror_num;
int i;
atomic_inc(&stripe->pending_io);
for_each_set_bit(i, &stripe->extent_sector_bitmap, stripe->nr_sectors) {
struct page *page = scrub_stripe_get_page(stripe, i);
unsigned int pgoff = scrub_stripe_get_page_offset(stripe, i);
/* The current sector cannot be merged, submit the bio. */
if (bbio &&
((i > 0 &&
!test_bit(i - 1, &stripe->extent_sector_bitmap)) ||
bbio->bio.bi_iter.bi_size >= stripe_len)) {
ASSERT(bbio->bio.bi_iter.bi_size);
atomic_inc(&stripe->pending_io);
btrfs_submit_bio(bbio, mirror);
bbio = NULL;
}
if (!bbio) {
struct btrfs_io_stripe io_stripe = {};
struct btrfs_io_context *bioc = NULL;
const u64 logical = stripe->logical +
(i << fs_info->sectorsize_bits);
int err;
bbio = btrfs_bio_alloc(stripe->nr_sectors, REQ_OP_READ,
fs_info, scrub_read_endio, stripe);
bbio->bio.bi_iter.bi_sector = logical >> SECTOR_SHIFT;
io_stripe.is_scrub = true;
err = btrfs_map_block(fs_info, BTRFS_MAP_READ, logical,
&stripe_len, &bioc, &io_stripe,
&mirror);
btrfs_put_bioc(bioc);
if (err) {
btrfs_bio_end_io(bbio,
errno_to_blk_status(err));
return;
}
}
__bio_add_page(&bbio->bio, page, fs_info->sectorsize, pgoff);
}
if (bbio) {
ASSERT(bbio->bio.bi_iter.bi_size);
atomic_inc(&stripe->pending_io);
btrfs_submit_bio(bbio, mirror);
}
if (atomic_dec_and_test(&stripe->pending_io)) {
wake_up(&stripe->io_wait);
INIT_WORK(&stripe->work, scrub_stripe_read_repair_worker);
queue_work(stripe->bg->fs_info->scrub_workers, &stripe->work);
}
}
static void scrub_submit_initial_read(struct scrub_ctx *sctx,
struct scrub_stripe *stripe)
{
struct btrfs_fs_info *fs_info = sctx->fs_info;
struct btrfs_bio *bbio;
int mirror = stripe->mirror_num;
ASSERT(stripe->bg);
ASSERT(stripe->mirror_num > 0);
ASSERT(test_bit(SCRUB_STRIPE_FLAG_INITIALIZED, &stripe->state));
if (btrfs_need_stripe_tree_update(fs_info, stripe->bg->flags)) {
scrub_submit_extent_sector_read(sctx, stripe);
return;
}
bbio = btrfs_bio_alloc(SCRUB_STRIPE_PAGES, REQ_OP_READ, fs_info,
scrub_read_endio, stripe);
/* Read the whole stripe. */
bbio->bio.bi_iter.bi_sector = stripe->logical >> SECTOR_SHIFT;
for (int i = 0; i < BTRFS_STRIPE_LEN >> PAGE_SHIFT; i++) {
int ret;
ret = bio_add_page(&bbio->bio, stripe->pages[i], PAGE_SIZE, 0);
/* We should have allocated enough bio vectors. */
ASSERT(ret == PAGE_SIZE);
}
atomic_inc(&stripe->pending_io);
/*
* For dev-replace, either user asks to avoid the source dev, or
* the device is missing, we try the next mirror instead.
*/
if (sctx->is_dev_replace &&
(fs_info->dev_replace.cont_reading_from_srcdev_mode ==
BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_AVOID ||
!stripe->dev->bdev)) {
int num_copies = btrfs_num_copies(fs_info, stripe->bg->start,
stripe->bg->length);
mirror = calc_next_mirror(mirror, num_copies);
}
btrfs_submit_bio(bbio, mirror);
}
static bool stripe_has_metadata_error(struct scrub_stripe *stripe)
{
int i;
for_each_set_bit(i, &stripe->error_bitmap, stripe->nr_sectors) {
if (stripe->sectors[i].is_metadata) {
struct btrfs_fs_info *fs_info = stripe->bg->fs_info;
btrfs_err(fs_info,
"stripe %llu has unrepaired metadata sector at %llu",
stripe->logical,
stripe->logical + (i << fs_info->sectorsize_bits));
return true;
}
}
return false;
}
static void submit_initial_group_read(struct scrub_ctx *sctx,
unsigned int first_slot,
unsigned int nr_stripes)
{
struct blk_plug plug;
ASSERT(first_slot < SCRUB_TOTAL_STRIPES);
ASSERT(first_slot + nr_stripes <= SCRUB_TOTAL_STRIPES);
scrub_throttle_dev_io(sctx, sctx->stripes[0].dev,
btrfs_stripe_nr_to_offset(nr_stripes));
blk_start_plug(&plug);
for (int i = 0; i < nr_stripes; i++) {
struct scrub_stripe *stripe = &sctx->stripes[first_slot + i];
/* Those stripes should be initialized. */
ASSERT(test_bit(SCRUB_STRIPE_FLAG_INITIALIZED, &stripe->state));
scrub_submit_initial_read(sctx, stripe);
}
blk_finish_plug(&plug);
}
static int flush_scrub_stripes(struct scrub_ctx *sctx)
{
struct btrfs_fs_info *fs_info = sctx->fs_info;
struct scrub_stripe *stripe;
const int nr_stripes = sctx->cur_stripe;
int ret = 0;
if (!nr_stripes)
return 0;
ASSERT(test_bit(SCRUB_STRIPE_FLAG_INITIALIZED, &sctx->stripes[0].state));
/* Submit the stripes which are populated but not submitted. */
if (nr_stripes % SCRUB_STRIPES_PER_GROUP) {
const int first_slot = round_down(nr_stripes, SCRUB_STRIPES_PER_GROUP);
submit_initial_group_read(sctx, first_slot, nr_stripes - first_slot);
}
for (int i = 0; i < nr_stripes; i++) {
stripe = &sctx->stripes[i];
wait_event(stripe->repair_wait,
test_bit(SCRUB_STRIPE_FLAG_REPAIR_DONE, &stripe->state));
}
/* Submit for dev-replace. */
if (sctx->is_dev_replace) {
/*
* For dev-replace, if we know there is something wrong with
* metadata, we should immedately abort.
*/
for (int i = 0; i < nr_stripes; i++) {
if (stripe_has_metadata_error(&sctx->stripes[i])) {
ret = -EIO;
goto out;
}
}
for (int i = 0; i < nr_stripes; i++) {
unsigned long good;
stripe = &sctx->stripes[i];
ASSERT(stripe->dev == fs_info->dev_replace.srcdev);
bitmap_andnot(&good, &stripe->extent_sector_bitmap,
&stripe->error_bitmap, stripe->nr_sectors);
scrub_write_sectors(sctx, stripe, good, true);
}
}
/* Wait for the above writebacks to finish. */
for (int i = 0; i < nr_stripes; i++) {
stripe = &sctx->stripes[i];
wait_scrub_stripe_io(stripe);
scrub_reset_stripe(stripe);
}
out:
sctx->cur_stripe = 0;
return ret;
}
static void raid56_scrub_wait_endio(struct bio *bio)
{
complete(bio->bi_private);
}
static int queue_scrub_stripe(struct scrub_ctx *sctx, struct btrfs_block_group *bg,
struct btrfs_device *dev, int mirror_num,
u64 logical, u32 length, u64 physical,
u64 *found_logical_ret)
{
struct scrub_stripe *stripe;
int ret;
/*
* There should always be one slot left, as caller filling the last
* slot should flush them all.
*/
ASSERT(sctx->cur_stripe < SCRUB_TOTAL_STRIPES);
stripe = &sctx->stripes[sctx->cur_stripe];
scrub_reset_stripe(stripe);
ret = scrub_find_fill_first_stripe(bg, &sctx->extent_path,
&sctx->csum_path, dev, physical,
mirror_num, logical, length, stripe);
/* Either >0 as no more extents or <0 for error. */
if (ret)
return ret;
if (found_logical_ret)
*found_logical_ret = stripe->logical;
sctx->cur_stripe++;
/* We filled one group, submit it. */
if (sctx->cur_stripe % SCRUB_STRIPES_PER_GROUP == 0) {
const int first_slot = sctx->cur_stripe - SCRUB_STRIPES_PER_GROUP;
submit_initial_group_read(sctx, first_slot, SCRUB_STRIPES_PER_GROUP);
}
/* Last slot used, flush them all. */
if (sctx->cur_stripe == SCRUB_TOTAL_STRIPES)
return flush_scrub_stripes(sctx);
return 0;
}
static int scrub_raid56_parity_stripe(struct scrub_ctx *sctx,
struct btrfs_device *scrub_dev,
struct btrfs_block_group *bg,
struct map_lookup *map,
u64 full_stripe_start)
{
DECLARE_COMPLETION_ONSTACK(io_done);
struct btrfs_fs_info *fs_info = sctx->fs_info;
struct btrfs_raid_bio *rbio;
struct btrfs_io_context *bioc = NULL;
struct btrfs_path extent_path = { 0 };
struct btrfs_path csum_path = { 0 };
struct bio *bio;
struct scrub_stripe *stripe;
bool all_empty = true;
const int data_stripes = nr_data_stripes(map);
unsigned long extent_bitmap = 0;
u64 length = btrfs_stripe_nr_to_offset(data_stripes);
int ret;
ASSERT(sctx->raid56_data_stripes);
/*
* For data stripe search, we cannot re-use the same extent/csum paths,
* as the data stripe bytenr may be smaller than previous extent. Thus
* we have to use our own extent/csum paths.
*/
extent_path.search_commit_root = 1;
extent_path.skip_locking = 1;
csum_path.search_commit_root = 1;
csum_path.skip_locking = 1;
for (int i = 0; i < data_stripes; i++) {
int stripe_index;
int rot;
u64 physical;
stripe = &sctx->raid56_data_stripes[i];
rot = div_u64(full_stripe_start - bg->start,
data_stripes) >> BTRFS_STRIPE_LEN_SHIFT;
stripe_index = (i + rot) % map->num_stripes;
physical = map->stripes[stripe_index].physical +
btrfs_stripe_nr_to_offset(rot);
scrub_reset_stripe(stripe);
set_bit(SCRUB_STRIPE_FLAG_NO_REPORT, &stripe->state);
ret = scrub_find_fill_first_stripe(bg, &extent_path, &csum_path,
map->stripes[stripe_index].dev, physical, 1,
full_stripe_start + btrfs_stripe_nr_to_offset(i),
BTRFS_STRIPE_LEN, stripe);
if (ret < 0)
goto out;
/*
* No extent in this data stripe, need to manually mark them
* initialized to make later read submission happy.
*/
if (ret > 0) {
stripe->logical = full_stripe_start +
btrfs_stripe_nr_to_offset(i);
stripe->dev = map->stripes[stripe_index].dev;
stripe->mirror_num = 1;
set_bit(SCRUB_STRIPE_FLAG_INITIALIZED, &stripe->state);
}
}
/* Check if all data stripes are empty. */
for (int i = 0; i < data_stripes; i++) {
stripe = &sctx->raid56_data_stripes[i];
if (!bitmap_empty(&stripe->extent_sector_bitmap, stripe->nr_sectors)) {
all_empty = false;
break;
}
}
if (all_empty) {
ret = 0;
goto out;
}
for (int i = 0; i < data_stripes; i++) {
stripe = &sctx->raid56_data_stripes[i];
scrub_submit_initial_read(sctx, stripe);
}
for (int i = 0; i < data_stripes; i++) {
stripe = &sctx->raid56_data_stripes[i];
wait_event(stripe->repair_wait,
test_bit(SCRUB_STRIPE_FLAG_REPAIR_DONE, &stripe->state));
}
/* For now, no zoned support for RAID56. */
ASSERT(!btrfs_is_zoned(sctx->fs_info));
/*
* Now all data stripes are properly verified. Check if we have any
* unrepaired, if so abort immediately or we could further corrupt the
* P/Q stripes.
*
* During the loop, also populate extent_bitmap.
*/
for (int i = 0; i < data_stripes; i++) {
unsigned long error;
stripe = &sctx->raid56_data_stripes[i];
/*
* We should only check the errors where there is an extent.
* As we may hit an empty data stripe while it's missing.
*/
bitmap_and(&error, &stripe->error_bitmap,
&stripe->extent_sector_bitmap, stripe->nr_sectors);
if (!bitmap_empty(&error, stripe->nr_sectors)) {
btrfs_err(fs_info,
"unrepaired sectors detected, full stripe %llu data stripe %u errors %*pbl",
full_stripe_start, i, stripe->nr_sectors,
&error);
ret = -EIO;
goto out;
}
bitmap_or(&extent_bitmap, &extent_bitmap,
&stripe->extent_sector_bitmap, stripe->nr_sectors);
}
/* Now we can check and regenerate the P/Q stripe. */
bio = bio_alloc(NULL, 1, REQ_OP_READ, GFP_NOFS);
bio->bi_iter.bi_sector = full_stripe_start >> SECTOR_SHIFT;
bio->bi_private = &io_done;
bio->bi_end_io = raid56_scrub_wait_endio;
btrfs_bio_counter_inc_blocked(fs_info);
ret = btrfs_map_block(fs_info, BTRFS_MAP_WRITE, full_stripe_start,
&length, &bioc, NULL, NULL);
if (ret < 0) {
btrfs_put_bioc(bioc);
btrfs_bio_counter_dec(fs_info);
goto out;
}
rbio = raid56_parity_alloc_scrub_rbio(bio, bioc, scrub_dev, &extent_bitmap,
BTRFS_STRIPE_LEN >> fs_info->sectorsize_bits);
btrfs_put_bioc(bioc);
if (!rbio) {
ret = -ENOMEM;
btrfs_bio_counter_dec(fs_info);
goto out;
}
/* Use the recovered stripes as cache to avoid read them from disk again. */
for (int i = 0; i < data_stripes; i++) {
stripe = &sctx->raid56_data_stripes[i];
raid56_parity_cache_data_pages(rbio, stripe->pages,
full_stripe_start + (i << BTRFS_STRIPE_LEN_SHIFT));
}
raid56_parity_submit_scrub_rbio(rbio);
wait_for_completion_io(&io_done);
ret = blk_status_to_errno(bio->bi_status);
bio_put(bio);
btrfs_bio_counter_dec(fs_info);
btrfs_release_path(&extent_path);
btrfs_release_path(&csum_path);
out:
return ret;
}
/*
* Scrub one range which can only has simple mirror based profile.
* (Including all range in SINGLE/DUP/RAID1/RAID1C*, and each stripe in
* RAID0/RAID10).
*
* Since we may need to handle a subset of block group, we need @logical_start
* and @logical_length parameter.
*/
static int scrub_simple_mirror(struct scrub_ctx *sctx,
struct btrfs_block_group *bg,
struct map_lookup *map,
u64 logical_start, u64 logical_length,
struct btrfs_device *device,
u64 physical, int mirror_num)
{
struct btrfs_fs_info *fs_info = sctx->fs_info;
const u64 logical_end = logical_start + logical_length;
u64 cur_logical = logical_start;
int ret;
/* The range must be inside the bg */
ASSERT(logical_start >= bg->start && logical_end <= bg->start + bg->length);
/* Go through each extent items inside the logical range */
while (cur_logical < logical_end) {
u64 found_logical;
u64 cur_physical = physical + cur_logical - logical_start;
/* Canceled? */
if (atomic_read(&fs_info->scrub_cancel_req) ||
atomic_read(&sctx->cancel_req)) {
ret = -ECANCELED;
break;
}
/* Paused? */
if (atomic_read(&fs_info->scrub_pause_req)) {
/* Push queued extents */
scrub_blocked_if_needed(fs_info);
}
/* Block group removed? */
spin_lock(&bg->lock);
if (test_bit(BLOCK_GROUP_FLAG_REMOVED, &bg->runtime_flags)) {
spin_unlock(&bg->lock);
ret = 0;
break;
}
spin_unlock(&bg->lock);
ret = queue_scrub_stripe(sctx, bg, device, mirror_num,
cur_logical, logical_end - cur_logical,
cur_physical, &found_logical);
if (ret > 0) {
/* No more extent, just update the accounting */
sctx->stat.last_physical = physical + logical_length;
ret = 0;
break;
}
if (ret < 0)
break;
cur_logical = found_logical + BTRFS_STRIPE_LEN;
/* Don't hold CPU for too long time */
cond_resched();
}
return ret;
}
/* Calculate the full stripe length for simple stripe based profiles */
static u64 simple_stripe_full_stripe_len(const struct map_lookup *map)
{
ASSERT(map->type & (BTRFS_BLOCK_GROUP_RAID0 |
BTRFS_BLOCK_GROUP_RAID10));
return btrfs_stripe_nr_to_offset(map->num_stripes / map->sub_stripes);
}
/* Get the logical bytenr for the stripe */
static u64 simple_stripe_get_logical(struct map_lookup *map,
struct btrfs_block_group *bg,
int stripe_index)
{
ASSERT(map->type & (BTRFS_BLOCK_GROUP_RAID0 |
BTRFS_BLOCK_GROUP_RAID10));
ASSERT(stripe_index < map->num_stripes);
/*
* (stripe_index / sub_stripes) gives how many data stripes we need to
* skip.
*/
return btrfs_stripe_nr_to_offset(stripe_index / map->sub_stripes) +
bg->start;
}
/* Get the mirror number for the stripe */
static int simple_stripe_mirror_num(struct map_lookup *map, int stripe_index)
{
ASSERT(map->type & (BTRFS_BLOCK_GROUP_RAID0 |
BTRFS_BLOCK_GROUP_RAID10));
ASSERT(stripe_index < map->num_stripes);
/* For RAID0, it's fixed to 1, for RAID10 it's 0,1,0,1... */
return stripe_index % map->sub_stripes + 1;
}
static int scrub_simple_stripe(struct scrub_ctx *sctx,
struct btrfs_block_group *bg,
struct map_lookup *map,
struct btrfs_device *device,
int stripe_index)
{
const u64 logical_increment = simple_stripe_full_stripe_len(map);
const u64 orig_logical = simple_stripe_get_logical(map, bg, stripe_index);
const u64 orig_physical = map->stripes[stripe_index].physical;
const int mirror_num = simple_stripe_mirror_num(map, stripe_index);
u64 cur_logical = orig_logical;
u64 cur_physical = orig_physical;
int ret = 0;
while (cur_logical < bg->start + bg->length) {
/*
* Inside each stripe, RAID0 is just SINGLE, and RAID10 is
* just RAID1, so we can reuse scrub_simple_mirror() to scrub
* this stripe.
*/
ret = scrub_simple_mirror(sctx, bg, map, cur_logical,
BTRFS_STRIPE_LEN, device, cur_physical,
mirror_num);
if (ret)
return ret;
/* Skip to next stripe which belongs to the target device */
cur_logical += logical_increment;
/* For physical offset, we just go to next stripe */
cur_physical += BTRFS_STRIPE_LEN;
}
return ret;
}
static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
struct btrfs_block_group *bg,
struct extent_map *em,
struct btrfs_device *scrub_dev,
int stripe_index)
{
struct btrfs_fs_info *fs_info = sctx->fs_info;
struct map_lookup *map = em->map_lookup;
const u64 profile = map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK;
const u64 chunk_logical = bg->start;
int ret;
int ret2;
u64 physical = map->stripes[stripe_index].physical;
const u64 dev_stripe_len = btrfs_calc_stripe_length(em);
const u64 physical_end = physical + dev_stripe_len;
u64 logical;
u64 logic_end;
/* The logical increment after finishing one stripe */
u64 increment;
/* Offset inside the chunk */
u64 offset;
u64 stripe_logical;
int stop_loop = 0;
/* Extent_path should be released by now. */
ASSERT(sctx->extent_path.nodes[0] == NULL);
scrub_blocked_if_needed(fs_info);
if (sctx->is_dev_replace &&
btrfs_dev_is_sequential(sctx->wr_tgtdev, physical)) {
mutex_lock(&sctx->wr_lock);
sctx->write_pointer = physical;
mutex_unlock(&sctx->wr_lock);
}
/* Prepare the extra data stripes used by RAID56. */
if (profile & BTRFS_BLOCK_GROUP_RAID56_MASK) {
ASSERT(sctx->raid56_data_stripes == NULL);
sctx->raid56_data_stripes = kcalloc(nr_data_stripes(map),
sizeof(struct scrub_stripe),
GFP_KERNEL);
if (!sctx->raid56_data_stripes) {
ret = -ENOMEM;
goto out;
}
for (int i = 0; i < nr_data_stripes(map); i++) {
ret = init_scrub_stripe(fs_info,
&sctx->raid56_data_stripes[i]);
if (ret < 0)
goto out;
sctx->raid56_data_stripes[i].bg = bg;
sctx->raid56_data_stripes[i].sctx = sctx;
}
}
/*
* There used to be a big double loop to handle all profiles using the
* same routine, which grows larger and more gross over time.
*
* So here we handle each profile differently, so simpler profiles
* have simpler scrubbing function.
*/
if (!(profile & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10 |
BTRFS_BLOCK_GROUP_RAID56_MASK))) {
/*
* Above check rules out all complex profile, the remaining
* profiles are SINGLE|DUP|RAID1|RAID1C*, which is simple
* mirrored duplication without stripe.
*
* Only @physical and @mirror_num needs to calculated using
* @stripe_index.
*/
ret = scrub_simple_mirror(sctx, bg, map, bg->start, bg->length,
scrub_dev, map->stripes[stripe_index].physical,
stripe_index + 1);
offset = 0;
goto out;
}
if (profile & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10)) {
ret = scrub_simple_stripe(sctx, bg, map, scrub_dev, stripe_index);
offset = btrfs_stripe_nr_to_offset(stripe_index / map->sub_stripes);
goto out;
}
/* Only RAID56 goes through the old code */
ASSERT(map->type & BTRFS_BLOCK_GROUP_RAID56_MASK);
ret = 0;
/* Calculate the logical end of the stripe */
get_raid56_logic_offset(physical_end, stripe_index,
map, &logic_end, NULL);
logic_end += chunk_logical;
/* Initialize @offset in case we need to go to out: label */
get_raid56_logic_offset(physical, stripe_index, map, &offset, NULL);
increment = btrfs_stripe_nr_to_offset(nr_data_stripes(map));
/*
* Due to the rotation, for RAID56 it's better to iterate each stripe
* using their physical offset.
*/
while (physical < physical_end) {
ret = get_raid56_logic_offset(physical, stripe_index, map,
&logical, &stripe_logical);
logical += chunk_logical;
if (ret) {
/* it is parity strip */
stripe_logical += chunk_logical;
ret = scrub_raid56_parity_stripe(sctx, scrub_dev, bg,
map, stripe_logical);
if (ret)
goto out;
goto next;
}
/*
* Now we're at a data stripe, scrub each extents in the range.
*
* At this stage, if we ignore the repair part, inside each data
* stripe it is no different than SINGLE profile.
* We can reuse scrub_simple_mirror() here, as the repair part
* is still based on @mirror_num.
*/
ret = scrub_simple_mirror(sctx, bg, map, logical, BTRFS_STRIPE_LEN,
scrub_dev, physical, 1);
if (ret < 0)
goto out;
next:
logical += increment;
physical += BTRFS_STRIPE_LEN;
spin_lock(&sctx->stat_lock);
if (stop_loop)
sctx->stat.last_physical =
map->stripes[stripe_index].physical + dev_stripe_len;
else
sctx->stat.last_physical = physical;
spin_unlock(&sctx->stat_lock);
if (stop_loop)
break;
}
out:
ret2 = flush_scrub_stripes(sctx);
if (!ret)
ret = ret2;
btrfs_release_path(&sctx->extent_path);
btrfs_release_path(&sctx->csum_path);
if (sctx->raid56_data_stripes) {
for (int i = 0; i < nr_data_stripes(map); i++)
release_scrub_stripe(&sctx->raid56_data_stripes[i]);
kfree(sctx->raid56_data_stripes);
sctx->raid56_data_stripes = NULL;
}
if (sctx->is_dev_replace && ret >= 0) {
int ret2;
ret2 = sync_write_pointer_for_zoned(sctx,
chunk_logical + offset,
map->stripes[stripe_index].physical,
physical_end);
if (ret2)
ret = ret2;
}
return ret < 0 ? ret : 0;
}
static noinline_for_stack int scrub_chunk(struct scrub_ctx *sctx,
struct btrfs_block_group *bg,
struct btrfs_device *scrub_dev,
u64 dev_offset,
u64 dev_extent_len)
{
struct btrfs_fs_info *fs_info = sctx->fs_info;
struct extent_map_tree *map_tree = &fs_info->mapping_tree;
struct map_lookup *map;
struct extent_map *em;
int i;
int ret = 0;
read_lock(&map_tree->lock);
em = lookup_extent_mapping(map_tree, bg->start, bg->length);
read_unlock(&map_tree->lock);
if (!em) {
/*
* Might have been an unused block group deleted by the cleaner
* kthread or relocation.
*/
spin_lock(&bg->lock);
if (!test_bit(BLOCK_GROUP_FLAG_REMOVED, &bg->runtime_flags))
ret = -EINVAL;
spin_unlock(&bg->lock);
return ret;
}
if (em->start != bg->start)
goto out;
if (em->len < dev_extent_len)
goto out;
map = em->map_lookup;
for (i = 0; i < map->num_stripes; ++i) {
if (map->stripes[i].dev->bdev == scrub_dev->bdev &&
map->stripes[i].physical == dev_offset) {
ret = scrub_stripe(sctx, bg, em, scrub_dev, i);
if (ret)
goto out;
}
}
out:
free_extent_map(em);
return ret;
}
static int finish_extent_writes_for_zoned(struct btrfs_root *root,
struct btrfs_block_group *cache)
{
struct btrfs_fs_info *fs_info = cache->fs_info;
struct btrfs_trans_handle *trans;
if (!btrfs_is_zoned(fs_info))
return 0;
btrfs_wait_block_group_reservations(cache);
btrfs_wait_nocow_writers(cache);
btrfs_wait_ordered_roots(fs_info, U64_MAX, cache->start, cache->length);
trans = btrfs_join_transaction(root);
if (IS_ERR(trans))
return PTR_ERR(trans);
return btrfs_commit_transaction(trans);
}
static noinline_for_stack
int scrub_enumerate_chunks(struct scrub_ctx *sctx,
struct btrfs_device *scrub_dev, u64 start, u64 end)
{
struct btrfs_dev_extent *dev_extent = NULL;
struct btrfs_path *path;
struct btrfs_fs_info *fs_info = sctx->fs_info;
struct btrfs_root *root = fs_info->dev_root;
u64 chunk_offset;
int ret = 0;
int ro_set;
int slot;
struct extent_buffer *l;
struct btrfs_key key;
struct btrfs_key found_key;
struct btrfs_block_group *cache;
struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->reada = READA_FORWARD;
path->search_commit_root = 1;
path->skip_locking = 1;
key.objectid = scrub_dev->devid;
key.offset = 0ull;
key.type = BTRFS_DEV_EXTENT_KEY;
while (1) {
u64 dev_extent_len;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
break;
if (ret > 0) {
if (path->slots[0] >=
btrfs_header_nritems(path->nodes[0])) {
ret = btrfs_next_leaf(root, path);
if (ret < 0)
break;
if (ret > 0) {
ret = 0;
break;
}
} else {
ret = 0;
}
}
l = path->nodes[0];
slot = path->slots[0];
btrfs_item_key_to_cpu(l, &found_key, slot);
if (found_key.objectid != scrub_dev->devid)
break;
if (found_key.type != BTRFS_DEV_EXTENT_KEY)
break;
if (found_key.offset >= end)
break;
if (found_key.offset < key.offset)
break;
dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
dev_extent_len = btrfs_dev_extent_length(l, dev_extent);
if (found_key.offset + dev_extent_len <= start)
goto skip;
chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
/*
* get a reference on the corresponding block group to prevent
* the chunk from going away while we scrub it
*/
cache = btrfs_lookup_block_group(fs_info, chunk_offset);
/* some chunks are removed but not committed to disk yet,
* continue scrubbing */
if (!cache)
goto skip;
ASSERT(cache->start <= chunk_offset);
/*
* We are using the commit root to search for device extents, so
* that means we could have found a device extent item from a
* block group that was deleted in the current transaction. The
* logical start offset of the deleted block group, stored at
* @chunk_offset, might be part of the logical address range of
* a new block group (which uses different physical extents).
* In this case btrfs_lookup_block_group() has returned the new
* block group, and its start address is less than @chunk_offset.
*
* We skip such new block groups, because it's pointless to
* process them, as we won't find their extents because we search
* for them using the commit root of the extent tree. For a device
* replace it's also fine to skip it, we won't miss copying them
* to the target device because we have the write duplication
* setup through the regular write path (by btrfs_map_block()),
* and we have committed a transaction when we started the device
* replace, right after setting up the device replace state.
*/
if (cache->start < chunk_offset) {
btrfs_put_block_group(cache);
goto skip;
}
if (sctx->is_dev_replace && btrfs_is_zoned(fs_info)) {
if (!test_bit(BLOCK_GROUP_FLAG_TO_COPY, &cache->runtime_flags)) {
btrfs_put_block_group(cache);
goto skip;
}
}
/*
* Make sure that while we are scrubbing the corresponding block
* group doesn't get its logical address and its device extents
* reused for another block group, which can possibly be of a
* different type and different profile. We do this to prevent
* false error detections and crashes due to bogus attempts to
* repair extents.
*/
spin_lock(&cache->lock);
if (test_bit(BLOCK_GROUP_FLAG_REMOVED, &cache->runtime_flags)) {
spin_unlock(&cache->lock);
btrfs_put_block_group(cache);
goto skip;
}
btrfs_freeze_block_group(cache);
spin_unlock(&cache->lock);
/*
* we need call btrfs_inc_block_group_ro() with scrubs_paused,
* to avoid deadlock caused by:
* btrfs_inc_block_group_ro()
* -> btrfs_wait_for_commit()
* -> btrfs_commit_transaction()
* -> btrfs_scrub_pause()
*/
scrub_pause_on(fs_info);
/*
* Don't do chunk preallocation for scrub.
*
* This is especially important for SYSTEM bgs, or we can hit
* -EFBIG from btrfs_finish_chunk_alloc() like:
* 1. The only SYSTEM bg is marked RO.
* Since SYSTEM bg is small, that's pretty common.
* 2. New SYSTEM bg will be allocated
* Due to regular version will allocate new chunk.
* 3. New SYSTEM bg is empty and will get cleaned up
* Before cleanup really happens, it's marked RO again.
* 4. Empty SYSTEM bg get scrubbed
* We go back to 2.
*
* This can easily boost the amount of SYSTEM chunks if cleaner
* thread can't be triggered fast enough, and use up all space
* of btrfs_super_block::sys_chunk_array
*
* While for dev replace, we need to try our best to mark block
* group RO, to prevent race between:
* - Write duplication
* Contains latest data
* - Scrub copy
* Contains data from commit tree
*
* If target block group is not marked RO, nocow writes can
* be overwritten by scrub copy, causing data corruption.
* So for dev-replace, it's not allowed to continue if a block
* group is not RO.
*/
ret = btrfs_inc_block_group_ro(cache, sctx->is_dev_replace);
if (!ret && sctx->is_dev_replace) {
ret = finish_extent_writes_for_zoned(root, cache);
if (ret) {
btrfs_dec_block_group_ro(cache);
scrub_pause_off(fs_info);
btrfs_put_block_group(cache);
break;
}
}
if (ret == 0) {
ro_set = 1;
} else if (ret == -ENOSPC && !sctx->is_dev_replace &&
!(cache->flags & BTRFS_BLOCK_GROUP_RAID56_MASK)) {
/*
* btrfs_inc_block_group_ro return -ENOSPC when it
* failed in creating new chunk for metadata.
* It is not a problem for scrub, because
* metadata are always cowed, and our scrub paused
* commit_transactions.
*
* For RAID56 chunks, we have to mark them read-only
* for scrub, as later we would use our own cache
* out of RAID56 realm.
* Thus we want the RAID56 bg to be marked RO to
* prevent RMW from screwing up out cache.
*/
ro_set = 0;
} else if (ret == -ETXTBSY) {
btrfs_warn(fs_info,
"skipping scrub of block group %llu due to active swapfile",
cache->start);
scrub_pause_off(fs_info);
ret = 0;
goto skip_unfreeze;
} else {
btrfs_warn(fs_info,
"failed setting block group ro: %d", ret);
btrfs_unfreeze_block_group(cache);
btrfs_put_block_group(cache);
scrub_pause_off(fs_info);
break;
}
/*
* Now the target block is marked RO, wait for nocow writes to
* finish before dev-replace.
* COW is fine, as COW never overwrites extents in commit tree.
*/
if (sctx->is_dev_replace) {
btrfs_wait_nocow_writers(cache);
btrfs_wait_ordered_roots(fs_info, U64_MAX, cache->start,
cache->length);
}
scrub_pause_off(fs_info);
down_write(&dev_replace->rwsem);
dev_replace->cursor_right = found_key.offset + dev_extent_len;
dev_replace->cursor_left = found_key.offset;
dev_replace->item_needs_writeback = 1;
up_write(&dev_replace->rwsem);
ret = scrub_chunk(sctx, cache, scrub_dev, found_key.offset,
dev_extent_len);
if (sctx->is_dev_replace &&
!btrfs_finish_block_group_to_copy(dev_replace->srcdev,
cache, found_key.offset))
ro_set = 0;
down_write(&dev_replace->rwsem);
dev_replace->cursor_left = dev_replace->cursor_right;
dev_replace->item_needs_writeback = 1;
up_write(&dev_replace->rwsem);
if (ro_set)
btrfs_dec_block_group_ro(cache);
/*
* We might have prevented the cleaner kthread from deleting
* this block group if it was already unused because we raced
* and set it to RO mode first. So add it back to the unused
* list, otherwise it might not ever be deleted unless a manual
* balance is triggered or it becomes used and unused again.
*/
spin_lock(&cache->lock);
if (!test_bit(BLOCK_GROUP_FLAG_REMOVED, &cache->runtime_flags) &&
!cache->ro && cache->reserved == 0 && cache->used == 0) {
spin_unlock(&cache->lock);
if (btrfs_test_opt(fs_info, DISCARD_ASYNC))
btrfs_discard_queue_work(&fs_info->discard_ctl,
cache);
else
btrfs_mark_bg_unused(cache);
} else {
spin_unlock(&cache->lock);
}
skip_unfreeze:
btrfs_unfreeze_block_group(cache);
btrfs_put_block_group(cache);
if (ret)
break;
if (sctx->is_dev_replace &&
atomic64_read(&dev_replace->num_write_errors) > 0) {
ret = -EIO;
break;
}
if (sctx->stat.malloc_errors > 0) {
ret = -ENOMEM;
break;
}
skip:
key.offset = found_key.offset + dev_extent_len;
btrfs_release_path(path);
}
btrfs_free_path(path);
return ret;
}
static int scrub_one_super(struct scrub_ctx *sctx, struct btrfs_device *dev,
struct page *page, u64 physical, u64 generation)
{
struct btrfs_fs_info *fs_info = sctx->fs_info;
struct bio_vec bvec;
struct bio bio;
struct btrfs_super_block *sb = page_address(page);
int ret;
bio_init(&bio, dev->bdev, &bvec, 1, REQ_OP_READ);
bio.bi_iter.bi_sector = physical >> SECTOR_SHIFT;
__bio_add_page(&bio, page, BTRFS_SUPER_INFO_SIZE, 0);
ret = submit_bio_wait(&bio);
bio_uninit(&bio);
if (ret < 0)
return ret;
ret = btrfs_check_super_csum(fs_info, sb);
if (ret != 0) {
btrfs_err_rl(fs_info,
"super block at physical %llu devid %llu has bad csum",
physical, dev->devid);
return -EIO;
}
if (btrfs_super_generation(sb) != generation) {
btrfs_err_rl(fs_info,
"super block at physical %llu devid %llu has bad generation %llu expect %llu",
physical, dev->devid,
btrfs_super_generation(sb), generation);
return -EUCLEAN;
}
return btrfs_validate_super(fs_info, sb, -1);
}
static noinline_for_stack int scrub_supers(struct scrub_ctx *sctx,
struct btrfs_device *scrub_dev)
{
int i;
u64 bytenr;
u64 gen;
int ret = 0;
struct page *page;
struct btrfs_fs_info *fs_info = sctx->fs_info;
if (BTRFS_FS_ERROR(fs_info))
return -EROFS;
page = alloc_page(GFP_KERNEL);
if (!page) {
spin_lock(&sctx->stat_lock);
sctx->stat.malloc_errors++;
spin_unlock(&sctx->stat_lock);
return -ENOMEM;
}
/* Seed devices of a new filesystem has their own generation. */
if (scrub_dev->fs_devices != fs_info->fs_devices)
gen = scrub_dev->generation;
else
gen = btrfs_get_last_trans_committed(fs_info);
for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
bytenr = btrfs_sb_offset(i);
if (bytenr + BTRFS_SUPER_INFO_SIZE >
scrub_dev->commit_total_bytes)
break;
if (!btrfs_check_super_location(scrub_dev, bytenr))
continue;
ret = scrub_one_super(sctx, scrub_dev, page, bytenr, gen);
if (ret) {
spin_lock(&sctx->stat_lock);
sctx->stat.super_errors++;
spin_unlock(&sctx->stat_lock);
}
}
__free_page(page);
return 0;
}
static void scrub_workers_put(struct btrfs_fs_info *fs_info)
{
if (refcount_dec_and_mutex_lock(&fs_info->scrub_workers_refcnt,
&fs_info->scrub_lock)) {
struct workqueue_struct *scrub_workers = fs_info->scrub_workers;
fs_info->scrub_workers = NULL;
mutex_unlock(&fs_info->scrub_lock);
if (scrub_workers)
destroy_workqueue(scrub_workers);
}
}
/*
* get a reference count on fs_info->scrub_workers. start worker if necessary
*/
static noinline_for_stack int scrub_workers_get(struct btrfs_fs_info *fs_info)
{
struct workqueue_struct *scrub_workers = NULL;
unsigned int flags = WQ_FREEZABLE | WQ_UNBOUND;
int max_active = fs_info->thread_pool_size;
int ret = -ENOMEM;
if (refcount_inc_not_zero(&fs_info->scrub_workers_refcnt))
return 0;
scrub_workers = alloc_workqueue("btrfs-scrub", flags, max_active);
if (!scrub_workers)
return -ENOMEM;
mutex_lock(&fs_info->scrub_lock);
if (refcount_read(&fs_info->scrub_workers_refcnt) == 0) {
ASSERT(fs_info->scrub_workers == NULL);
fs_info->scrub_workers = scrub_workers;
refcount_set(&fs_info->scrub_workers_refcnt, 1);
mutex_unlock(&fs_info->scrub_lock);
return 0;
}
/* Other thread raced in and created the workers for us */
refcount_inc(&fs_info->scrub_workers_refcnt);
mutex_unlock(&fs_info->scrub_lock);
ret = 0;
destroy_workqueue(scrub_workers);
return ret;
}
int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start,
u64 end, struct btrfs_scrub_progress *progress,
int readonly, int is_dev_replace)
{
struct btrfs_dev_lookup_args args = { .devid = devid };
struct scrub_ctx *sctx;
int ret;
struct btrfs_device *dev;
unsigned int nofs_flag;
bool need_commit = false;
if (btrfs_fs_closing(fs_info))
return -EAGAIN;
/* At mount time we have ensured nodesize is in the range of [4K, 64K]. */
ASSERT(fs_info->nodesize <= BTRFS_STRIPE_LEN);
/*
* SCRUB_MAX_SECTORS_PER_BLOCK is calculated using the largest possible
* value (max nodesize / min sectorsize), thus nodesize should always
* be fine.
*/
ASSERT(fs_info->nodesize <=
SCRUB_MAX_SECTORS_PER_BLOCK << fs_info->sectorsize_bits);
/* Allocate outside of device_list_mutex */
sctx = scrub_setup_ctx(fs_info, is_dev_replace);
if (IS_ERR(sctx))
return PTR_ERR(sctx);
ret = scrub_workers_get(fs_info);
if (ret)
goto out_free_ctx;
mutex_lock(&fs_info->fs_devices->device_list_mutex);
dev = btrfs_find_device(fs_info->fs_devices, &args);
if (!dev || (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state) &&
!is_dev_replace)) {
mutex_unlock(&fs_info->fs_devices->device_list_mutex);
ret = -ENODEV;
goto out;
}
if (!is_dev_replace && !readonly &&
!test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state)) {
mutex_unlock(&fs_info->fs_devices->device_list_mutex);
btrfs_err_in_rcu(fs_info,
"scrub on devid %llu: filesystem on %s is not writable",
devid, btrfs_dev_name(dev));
ret = -EROFS;
goto out;
}
mutex_lock(&fs_info->scrub_lock);
if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) ||
test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &dev->dev_state)) {
mutex_unlock(&fs_info->scrub_lock);
mutex_unlock(&fs_info->fs_devices->device_list_mutex);
ret = -EIO;
goto out;
}
down_read(&fs_info->dev_replace.rwsem);
if (dev->scrub_ctx ||
(!is_dev_replace &&
btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))) {
up_read(&fs_info->dev_replace.rwsem);
mutex_unlock(&fs_info->scrub_lock);
mutex_unlock(&fs_info->fs_devices->device_list_mutex);
ret = -EINPROGRESS;
goto out;
}
up_read(&fs_info->dev_replace.rwsem);
sctx->readonly = readonly;
dev->scrub_ctx = sctx;
mutex_unlock(&fs_info->fs_devices->device_list_mutex);
/*
* checking @scrub_pause_req here, we can avoid
* race between committing transaction and scrubbing.
*/
__scrub_blocked_if_needed(fs_info);
atomic_inc(&fs_info->scrubs_running);
mutex_unlock(&fs_info->scrub_lock);
/*
* In order to avoid deadlock with reclaim when there is a transaction
* trying to pause scrub, make sure we use GFP_NOFS for all the
* allocations done at btrfs_scrub_sectors() and scrub_sectors_for_parity()
* invoked by our callees. The pausing request is done when the
* transaction commit starts, and it blocks the transaction until scrub
* is paused (done at specific points at scrub_stripe() or right above
* before incrementing fs_info->scrubs_running).
*/
nofs_flag = memalloc_nofs_save();
if (!is_dev_replace) {
u64 old_super_errors;
spin_lock(&sctx->stat_lock);
old_super_errors = sctx->stat.super_errors;
spin_unlock(&sctx->stat_lock);
btrfs_info(fs_info, "scrub: started on devid %llu", devid);
/*
* by holding device list mutex, we can
* kick off writing super in log tree sync.
*/
mutex_lock(&fs_info->fs_devices->device_list_mutex);
ret = scrub_supers(sctx, dev);
mutex_unlock(&fs_info->fs_devices->device_list_mutex);
spin_lock(&sctx->stat_lock);
/*
* Super block errors found, but we can not commit transaction
* at current context, since btrfs_commit_transaction() needs
* to pause the current running scrub (hold by ourselves).
*/
if (sctx->stat.super_errors > old_super_errors && !sctx->readonly)
need_commit = true;
spin_unlock(&sctx->stat_lock);
}
if (!ret)
ret = scrub_enumerate_chunks(sctx, dev, start, end);
memalloc_nofs_restore(nofs_flag);
atomic_dec(&fs_info->scrubs_running);
wake_up(&fs_info->scrub_pause_wait);
if (progress)
memcpy(progress, &sctx->stat, sizeof(*progress));
if (!is_dev_replace)
btrfs_info(fs_info, "scrub: %s on devid %llu with status: %d",
ret ? "not finished" : "finished", devid, ret);
mutex_lock(&fs_info->scrub_lock);
dev->scrub_ctx = NULL;
mutex_unlock(&fs_info->scrub_lock);
scrub_workers_put(fs_info);
scrub_put_ctx(sctx);
/*
* We found some super block errors before, now try to force a
* transaction commit, as scrub has finished.
*/
if (need_commit) {
struct btrfs_trans_handle *trans;
trans = btrfs_start_transaction(fs_info->tree_root, 0);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
btrfs_err(fs_info,
"scrub: failed to start transaction to fix super block errors: %d", ret);
return ret;
}
ret = btrfs_commit_transaction(trans);
if (ret < 0)
btrfs_err(fs_info,
"scrub: failed to commit transaction to fix super block errors: %d", ret);
}
return ret;
out:
scrub_workers_put(fs_info);
out_free_ctx:
scrub_free_ctx(sctx);
return ret;
}
void btrfs_scrub_pause(struct btrfs_fs_info *fs_info)
{
mutex_lock(&fs_info->scrub_lock);
atomic_inc(&fs_info->scrub_pause_req);
while (atomic_read(&fs_info->scrubs_paused) !=
atomic_read(&fs_info->scrubs_running)) {
mutex_unlock(&fs_info->scrub_lock);
wait_event(fs_info->scrub_pause_wait,
atomic_read(&fs_info->scrubs_paused) ==
atomic_read(&fs_info->scrubs_running));
mutex_lock(&fs_info->scrub_lock);
}
mutex_unlock(&fs_info->scrub_lock);
}
void btrfs_scrub_continue(struct btrfs_fs_info *fs_info)
{
atomic_dec(&fs_info->scrub_pause_req);
wake_up(&fs_info->scrub_pause_wait);
}
int btrfs_scrub_cancel(struct btrfs_fs_info *fs_info)
{
mutex_lock(&fs_info->scrub_lock);
if (!atomic_read(&fs_info->scrubs_running)) {
mutex_unlock(&fs_info->scrub_lock);
return -ENOTCONN;
}
atomic_inc(&fs_info->scrub_cancel_req);
while (atomic_read(&fs_info->scrubs_running)) {
mutex_unlock(&fs_info->scrub_lock);
wait_event(fs_info->scrub_pause_wait,
atomic_read(&fs_info->scrubs_running) == 0);
mutex_lock(&fs_info->scrub_lock);
}
atomic_dec(&fs_info->scrub_cancel_req);
mutex_unlock(&fs_info->scrub_lock);
return 0;
}
int btrfs_scrub_cancel_dev(struct btrfs_device *dev)
{
struct btrfs_fs_info *fs_info = dev->fs_info;
struct scrub_ctx *sctx;
mutex_lock(&fs_info->scrub_lock);
sctx = dev->scrub_ctx;
if (!sctx) {
mutex_unlock(&fs_info->scrub_lock);
return -ENOTCONN;
}
atomic_inc(&sctx->cancel_req);
while (dev->scrub_ctx) {
mutex_unlock(&fs_info->scrub_lock);
wait_event(fs_info->scrub_pause_wait,
dev->scrub_ctx == NULL);
mutex_lock(&fs_info->scrub_lock);
}
mutex_unlock(&fs_info->scrub_lock);
return 0;
}
int btrfs_scrub_progress(struct btrfs_fs_info *fs_info, u64 devid,
struct btrfs_scrub_progress *progress)
{
struct btrfs_dev_lookup_args args = { .devid = devid };
struct btrfs_device *dev;
struct scrub_ctx *sctx = NULL;
mutex_lock(&fs_info->fs_devices->device_list_mutex);
dev = btrfs_find_device(fs_info->fs_devices, &args);
if (dev)
sctx = dev->scrub_ctx;
if (sctx)
memcpy(progress, &sctx->stat, sizeof(*progress));
mutex_unlock(&fs_info->fs_devices->device_list_mutex);
return dev ? (sctx ? 0 : -ENOTCONN) : -ENODEV;
}
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