linux/fs/btrfs/zoned.c

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// SPDX-License-Identifier: GPL-2.0
#include <linux/slab.h>
#include <linux/blkdev.h>
#include "ctree.h"
#include "volumes.h"
#include "zoned.h"
#include "rcu-string.h"
/* Maximum number of zones to report per blkdev_report_zones() call */
#define BTRFS_REPORT_NR_ZONES 4096
btrfs: implement log-structured superblock for ZONED mode Superblock (and its copies) is the only data structure in btrfs which has a fixed location on a device. Since we cannot overwrite in a sequential write required zone, we cannot place superblock in the zone. One easy solution is limiting superblock and copies to be placed only in conventional zones. However, this method has two downsides: one is reduced number of superblock copies. The location of the second copy of superblock is 256GB, which is in a sequential write required zone on typical devices in the market today. So, the number of superblock and copies is limited to be two. Second downside is that we cannot support devices which have no conventional zones at all. To solve these two problems, we employ superblock log writing. It uses two adjacent zones as a circular buffer to write updated superblocks. Once the first zone is filled up, start writing into the second one. Then, when both zones are filled up and before starting to write to the first zone again, it reset the first zone. We can determine the position of the latest superblock by reading write pointer information from a device. One corner case is when both zones are full. For this situation, we read out the last superblock of each zone, and compare them to determine which zone is older. The following zones are reserved as the circular buffer on ZONED btrfs. - The primary superblock: zones 0 and 1 - The first copy: zones 16 and 17 - The second copy: zones 1024 or zone at 256GB which is minimum, and next to it If these reserved zones are conventional, superblock is written fixed at the start of the zone without logging. Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-11-10 11:26:14 +00:00
/* Number of superblock log zones */
#define BTRFS_NR_SB_LOG_ZONES 2
static int copy_zone_info_cb(struct blk_zone *zone, unsigned int idx, void *data)
{
struct blk_zone *zones = data;
memcpy(&zones[idx], zone, sizeof(*zone));
return 0;
}
btrfs: implement log-structured superblock for ZONED mode Superblock (and its copies) is the only data structure in btrfs which has a fixed location on a device. Since we cannot overwrite in a sequential write required zone, we cannot place superblock in the zone. One easy solution is limiting superblock and copies to be placed only in conventional zones. However, this method has two downsides: one is reduced number of superblock copies. The location of the second copy of superblock is 256GB, which is in a sequential write required zone on typical devices in the market today. So, the number of superblock and copies is limited to be two. Second downside is that we cannot support devices which have no conventional zones at all. To solve these two problems, we employ superblock log writing. It uses two adjacent zones as a circular buffer to write updated superblocks. Once the first zone is filled up, start writing into the second one. Then, when both zones are filled up and before starting to write to the first zone again, it reset the first zone. We can determine the position of the latest superblock by reading write pointer information from a device. One corner case is when both zones are full. For this situation, we read out the last superblock of each zone, and compare them to determine which zone is older. The following zones are reserved as the circular buffer on ZONED btrfs. - The primary superblock: zones 0 and 1 - The first copy: zones 16 and 17 - The second copy: zones 1024 or zone at 256GB which is minimum, and next to it If these reserved zones are conventional, superblock is written fixed at the start of the zone without logging. Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-11-10 11:26:14 +00:00
static int sb_write_pointer(struct block_device *bdev, struct blk_zone *zones,
u64 *wp_ret)
{
bool empty[BTRFS_NR_SB_LOG_ZONES];
bool full[BTRFS_NR_SB_LOG_ZONES];
sector_t sector;
ASSERT(zones[0].type != BLK_ZONE_TYPE_CONVENTIONAL &&
zones[1].type != BLK_ZONE_TYPE_CONVENTIONAL);
empty[0] = (zones[0].cond == BLK_ZONE_COND_EMPTY);
empty[1] = (zones[1].cond == BLK_ZONE_COND_EMPTY);
full[0] = (zones[0].cond == BLK_ZONE_COND_FULL);
full[1] = (zones[1].cond == BLK_ZONE_COND_FULL);
/*
* Possible states of log buffer zones
*
* Empty[0] In use[0] Full[0]
* Empty[1] * x 0
* In use[1] 0 x 0
* Full[1] 1 1 C
*
* Log position:
* *: Special case, no superblock is written
* 0: Use write pointer of zones[0]
* 1: Use write pointer of zones[1]
* C: Compare super blcoks from zones[0] and zones[1], use the latest
* one determined by generation
* x: Invalid state
*/
if (empty[0] && empty[1]) {
/* Special case to distinguish no superblock to read */
*wp_ret = zones[0].start << SECTOR_SHIFT;
return -ENOENT;
} else if (full[0] && full[1]) {
/* Compare two super blocks */
struct address_space *mapping = bdev->bd_inode->i_mapping;
struct page *page[BTRFS_NR_SB_LOG_ZONES];
struct btrfs_super_block *super[BTRFS_NR_SB_LOG_ZONES];
int i;
for (i = 0; i < BTRFS_NR_SB_LOG_ZONES; i++) {
u64 bytenr;
bytenr = ((zones[i].start + zones[i].len)
<< SECTOR_SHIFT) - BTRFS_SUPER_INFO_SIZE;
page[i] = read_cache_page_gfp(mapping,
bytenr >> PAGE_SHIFT, GFP_NOFS);
if (IS_ERR(page[i])) {
if (i == 1)
btrfs_release_disk_super(super[0]);
return PTR_ERR(page[i]);
}
super[i] = page_address(page[i]);
}
if (super[0]->generation > super[1]->generation)
sector = zones[1].start;
else
sector = zones[0].start;
for (i = 0; i < BTRFS_NR_SB_LOG_ZONES; i++)
btrfs_release_disk_super(super[i]);
} else if (!full[0] && (empty[1] || full[1])) {
sector = zones[0].wp;
} else if (full[0]) {
sector = zones[1].wp;
} else {
return -EUCLEAN;
}
*wp_ret = sector << SECTOR_SHIFT;
return 0;
}
/*
* The following zones are reserved as the circular buffer on ZONED btrfs.
* - The primary superblock: zones 0 and 1
* - The first copy: zones 16 and 17
* - The second copy: zones 1024 or zone at 256GB which is minimum, and
* the following one
*/
static inline u32 sb_zone_number(int shift, int mirror)
{
ASSERT(mirror < BTRFS_SUPER_MIRROR_MAX);
switch (mirror) {
case 0: return 0;
case 1: return 16;
case 2: return min_t(u64, btrfs_sb_offset(mirror) >> shift, 1024);
}
return 0;
}
static int btrfs_get_dev_zones(struct btrfs_device *device, u64 pos,
struct blk_zone *zones, unsigned int *nr_zones)
{
int ret;
if (!*nr_zones)
return 0;
ret = blkdev_report_zones(device->bdev, pos >> SECTOR_SHIFT, *nr_zones,
copy_zone_info_cb, zones);
if (ret < 0) {
btrfs_err_in_rcu(device->fs_info,
"zoned: failed to read zone %llu on %s (devid %llu)",
pos, rcu_str_deref(device->name),
device->devid);
return ret;
}
*nr_zones = ret;
if (!ret)
return -EIO;
return 0;
}
int btrfs_get_dev_zone_info_all_devices(struct btrfs_fs_info *fs_info)
{
struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
struct btrfs_device *device;
int ret = 0;
/* fs_info->zone_size might not set yet. Use the incomapt flag here. */
if (!btrfs_fs_incompat(fs_info, ZONED))
return 0;
mutex_lock(&fs_devices->device_list_mutex);
list_for_each_entry(device, &fs_devices->devices, dev_list) {
/* We can skip reading of zone info for missing devices */
if (!device->bdev)
continue;
ret = btrfs_get_dev_zone_info(device);
if (ret)
break;
}
mutex_unlock(&fs_devices->device_list_mutex);
return ret;
}
int btrfs_get_dev_zone_info(struct btrfs_device *device)
{
struct btrfs_zoned_device_info *zone_info = NULL;
struct block_device *bdev = device->bdev;
struct request_queue *queue = bdev_get_queue(bdev);
sector_t nr_sectors;
sector_t sector = 0;
struct blk_zone *zones = NULL;
unsigned int i, nreported = 0, nr_zones;
unsigned int zone_sectors;
int ret;
if (!bdev_is_zoned(bdev))
return 0;
if (device->zone_info)
return 0;
zone_info = kzalloc(sizeof(*zone_info), GFP_KERNEL);
if (!zone_info)
return -ENOMEM;
for-5.11/block-2020-12-14 -----BEGIN PGP SIGNATURE----- iQJEBAABCAAuFiEEwPw5LcreJtl1+l5K99NY+ylx4KYFAl/Xec8QHGF4Ym9lQGtl cm5lbC5kawAKCRD301j7KXHgpoLbEACzXypgZWwMdfgRckA/Vt333rXHtbhUV+hK 2XP+P81iRvr9Esi31UPbRp82vrgcDO0cpI1QmQojS5U5TIQP88BfXptfRZZu48eb wT5RDDNQ34HItqAh/yEuYsv9yUKcxeIrB99tBVvM+4UmQg9zTdIW3mg6PvCBdbhV N38jI0tCF/PJatjfRuphT/nXonQLPWBlVDmZk06KZQFOwQe9ep1vUi1+nbiRPuo3 geFBpTh1Kp6Vl1B3n4RpECs6Y7I0RRuJdaH2sDizICla1/BW91F9fQwHimNnUxUq e1Q1kMuh6ftcQGkYlHSYcPhuv6CvorldTZCO5arPxWpcwvxriTSMRPWAgUr5pEiF fhiGhqeDu9e6vl9vS31wUD1B30hy+jFz9wyjRrDwJ3cPHH1JVBjTzvdX+cIh/1ku IbIwUMteUtvUrzqAv/DzbGhedp7xWtOFaVo8j0QFYh9zkjd6b8yDOF/yztwX2gjY Xt1cd+KpDSiN449ZRaoMI0sCJAxqzhMa6nsWlb0L7KuNyWKAbvKQBm9Rb47FLV9A Vx70KC+zkFoyw23capvIahmQazerriUJ5PGe0lVm6ROgmIFdCpXTPDjnrvq/6RZ/ GEpD7gTW9atGJ7EuEE8686sAfKD5kneChWLX5EHXf0d0AG5Mr2lKsluiGp5LpPJg Q1Xqs6xwww== =zo4w -----END PGP SIGNATURE----- Merge tag 'for-5.11/block-2020-12-14' of git://git.kernel.dk/linux-block Pull block updates from Jens Axboe: "Another series of killing more code than what is being added, again thanks to Christoph's relentless cleanups and tech debt tackling. This contains: - blk-iocost improvements (Baolin Wang) - part0 iostat fix (Jeffle Xu) - Disable iopoll for split bios (Jeffle Xu) - block tracepoint cleanups (Christoph Hellwig) - Merging of struct block_device and hd_struct (Christoph Hellwig) - Rework/cleanup of how block device sizes are updated (Christoph Hellwig) - Simplification of gendisk lookup and removal of block device aliasing (Christoph Hellwig) - Block device ioctl cleanups (Christoph Hellwig) - Removal of bdget()/blkdev_get() as exported API (Christoph Hellwig) - Disk change rework, avoid ->revalidate_disk() (Christoph Hellwig) - sbitmap improvements (Pavel Begunkov) - Hybrid polling fix (Pavel Begunkov) - bvec iteration improvements (Pavel Begunkov) - Zone revalidation fixes (Damien Le Moal) - blk-throttle limit fix (Yu Kuai) - Various little fixes" * tag 'for-5.11/block-2020-12-14' of git://git.kernel.dk/linux-block: (126 commits) blk-mq: fix msec comment from micro to milli seconds blk-mq: update arg in comment of blk_mq_map_queue blk-mq: add helper allocating tagset->tags Revert "block: Fix a lockdep complaint triggered by request queue flushing" nvme-loop: use blk_mq_hctx_set_fq_lock_class to set loop's lock class blk-mq: add new API of blk_mq_hctx_set_fq_lock_class block: disable iopoll for split bio block: Improve blk_revalidate_disk_zones() checks sbitmap: simplify wrap check sbitmap: replace CAS with atomic and sbitmap: remove swap_lock sbitmap: optimise sbitmap_deferred_clear() blk-mq: skip hybrid polling if iopoll doesn't spin blk-iocost: Factor out the base vrate change into a separate function blk-iocost: Factor out the active iocgs' state check into a separate function blk-iocost: Move the usage ratio calculation to the correct place blk-iocost: Remove unnecessary advance declaration blk-iocost: Fix some typos in comments blktrace: fix up a kerneldoc comment block: remove the request_queue to argument request based tracepoints ...
2020-12-16 20:57:51 +00:00
nr_sectors = bdev_nr_sectors(bdev);
zone_sectors = bdev_zone_sectors(bdev);
/* Check if it's power of 2 (see is_power_of_2) */
ASSERT(zone_sectors != 0 && (zone_sectors & (zone_sectors - 1)) == 0);
zone_info->zone_size = zone_sectors << SECTOR_SHIFT;
zone_info->zone_size_shift = ilog2(zone_info->zone_size);
zone_info->max_zone_append_size =
(u64)queue_max_zone_append_sectors(queue) << SECTOR_SHIFT;
zone_info->nr_zones = nr_sectors >> ilog2(zone_sectors);
if (!IS_ALIGNED(nr_sectors, zone_sectors))
zone_info->nr_zones++;
zone_info->seq_zones = bitmap_zalloc(zone_info->nr_zones, GFP_KERNEL);
if (!zone_info->seq_zones) {
ret = -ENOMEM;
goto out;
}
zone_info->empty_zones = bitmap_zalloc(zone_info->nr_zones, GFP_KERNEL);
if (!zone_info->empty_zones) {
ret = -ENOMEM;
goto out;
}
zones = kcalloc(BTRFS_REPORT_NR_ZONES, sizeof(struct blk_zone), GFP_KERNEL);
if (!zones) {
ret = -ENOMEM;
goto out;
}
/* Get zones type */
while (sector < nr_sectors) {
nr_zones = BTRFS_REPORT_NR_ZONES;
ret = btrfs_get_dev_zones(device, sector << SECTOR_SHIFT, zones,
&nr_zones);
if (ret)
goto out;
for (i = 0; i < nr_zones; i++) {
if (zones[i].type == BLK_ZONE_TYPE_SEQWRITE_REQ)
__set_bit(nreported, zone_info->seq_zones);
if (zones[i].cond == BLK_ZONE_COND_EMPTY)
__set_bit(nreported, zone_info->empty_zones);
nreported++;
}
sector = zones[nr_zones - 1].start + zones[nr_zones - 1].len;
}
if (nreported != zone_info->nr_zones) {
btrfs_err_in_rcu(device->fs_info,
"inconsistent number of zones on %s (%u/%u)",
rcu_str_deref(device->name), nreported,
zone_info->nr_zones);
ret = -EIO;
goto out;
}
btrfs: implement log-structured superblock for ZONED mode Superblock (and its copies) is the only data structure in btrfs which has a fixed location on a device. Since we cannot overwrite in a sequential write required zone, we cannot place superblock in the zone. One easy solution is limiting superblock and copies to be placed only in conventional zones. However, this method has two downsides: one is reduced number of superblock copies. The location of the second copy of superblock is 256GB, which is in a sequential write required zone on typical devices in the market today. So, the number of superblock and copies is limited to be two. Second downside is that we cannot support devices which have no conventional zones at all. To solve these two problems, we employ superblock log writing. It uses two adjacent zones as a circular buffer to write updated superblocks. Once the first zone is filled up, start writing into the second one. Then, when both zones are filled up and before starting to write to the first zone again, it reset the first zone. We can determine the position of the latest superblock by reading write pointer information from a device. One corner case is when both zones are full. For this situation, we read out the last superblock of each zone, and compare them to determine which zone is older. The following zones are reserved as the circular buffer on ZONED btrfs. - The primary superblock: zones 0 and 1 - The first copy: zones 16 and 17 - The second copy: zones 1024 or zone at 256GB which is minimum, and next to it If these reserved zones are conventional, superblock is written fixed at the start of the zone without logging. Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-11-10 11:26:14 +00:00
/* Validate superblock log */
nr_zones = BTRFS_NR_SB_LOG_ZONES;
for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
u32 sb_zone;
u64 sb_wp;
int sb_pos = BTRFS_NR_SB_LOG_ZONES * i;
sb_zone = sb_zone_number(zone_info->zone_size_shift, i);
if (sb_zone + 1 >= zone_info->nr_zones)
continue;
sector = sb_zone << (zone_info->zone_size_shift - SECTOR_SHIFT);
ret = btrfs_get_dev_zones(device, sector << SECTOR_SHIFT,
&zone_info->sb_zones[sb_pos],
&nr_zones);
if (ret)
goto out;
if (nr_zones != BTRFS_NR_SB_LOG_ZONES) {
btrfs_err_in_rcu(device->fs_info,
"zoned: failed to read super block log zone info at devid %llu zone %u",
device->devid, sb_zone);
ret = -EUCLEAN;
goto out;
}
/*
* If zones[0] is conventional, always use the beggining of the
* zone to record superblock. No need to validate in that case.
*/
if (zone_info->sb_zones[BTRFS_NR_SB_LOG_ZONES * i].type ==
BLK_ZONE_TYPE_CONVENTIONAL)
continue;
ret = sb_write_pointer(device->bdev,
&zone_info->sb_zones[sb_pos], &sb_wp);
if (ret != -ENOENT && ret) {
btrfs_err_in_rcu(device->fs_info,
"zoned: super block log zone corrupted devid %llu zone %u",
device->devid, sb_zone);
ret = -EUCLEAN;
goto out;
}
}
kfree(zones);
device->zone_info = zone_info;
/* device->fs_info is not safe to use for printing messages */
btrfs_info_in_rcu(NULL,
"host-%s zoned block device %s, %u zones of %llu bytes",
bdev_zoned_model(bdev) == BLK_ZONED_HM ? "managed" : "aware",
rcu_str_deref(device->name), zone_info->nr_zones,
zone_info->zone_size);
return 0;
out:
kfree(zones);
bitmap_free(zone_info->empty_zones);
bitmap_free(zone_info->seq_zones);
kfree(zone_info);
return ret;
}
void btrfs_destroy_dev_zone_info(struct btrfs_device *device)
{
struct btrfs_zoned_device_info *zone_info = device->zone_info;
if (!zone_info)
return;
bitmap_free(zone_info->seq_zones);
bitmap_free(zone_info->empty_zones);
kfree(zone_info);
device->zone_info = NULL;
}
int btrfs_get_dev_zone(struct btrfs_device *device, u64 pos,
struct blk_zone *zone)
{
unsigned int nr_zones = 1;
int ret;
ret = btrfs_get_dev_zones(device, pos, zone, &nr_zones);
if (ret != 0 || !nr_zones)
return ret ? ret : -EIO;
return 0;
}
int btrfs_check_zoned_mode(struct btrfs_fs_info *fs_info)
{
struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
struct btrfs_device *device;
u64 zoned_devices = 0;
u64 nr_devices = 0;
u64 zone_size = 0;
u64 max_zone_append_size = 0;
const bool incompat_zoned = btrfs_is_zoned(fs_info);
int ret = 0;
/* Count zoned devices */
list_for_each_entry(device, &fs_devices->devices, dev_list) {
enum blk_zoned_model model;
if (!device->bdev)
continue;
model = bdev_zoned_model(device->bdev);
if (model == BLK_ZONED_HM ||
(model == BLK_ZONED_HA && incompat_zoned)) {
struct btrfs_zoned_device_info *zone_info;
zone_info = device->zone_info;
zoned_devices++;
if (!zone_size) {
zone_size = zone_info->zone_size;
} else if (zone_info->zone_size != zone_size) {
btrfs_err(fs_info,
"zoned: unequal block device zone sizes: have %llu found %llu",
device->zone_info->zone_size,
zone_size);
ret = -EINVAL;
goto out;
}
if (!max_zone_append_size ||
(zone_info->max_zone_append_size &&
zone_info->max_zone_append_size < max_zone_append_size))
max_zone_append_size =
zone_info->max_zone_append_size;
}
nr_devices++;
}
if (!zoned_devices && !incompat_zoned)
goto out;
if (!zoned_devices && incompat_zoned) {
/* No zoned block device found on ZONED filesystem */
btrfs_err(fs_info,
"zoned: no zoned devices found on a zoned filesystem");
ret = -EINVAL;
goto out;
}
if (zoned_devices && !incompat_zoned) {
btrfs_err(fs_info,
"zoned: mode not enabled but zoned device found");
ret = -EINVAL;
goto out;
}
if (zoned_devices != nr_devices) {
btrfs_err(fs_info,
"zoned: cannot mix zoned and regular devices");
ret = -EINVAL;
goto out;
}
/*
* stripe_size is always aligned to BTRFS_STRIPE_LEN in
* __btrfs_alloc_chunk(). Since we want stripe_len == zone_size,
* check the alignment here.
*/
if (!IS_ALIGNED(zone_size, BTRFS_STRIPE_LEN)) {
btrfs_err(fs_info,
"zoned: zone size %llu not aligned to stripe %u",
zone_size, BTRFS_STRIPE_LEN);
ret = -EINVAL;
goto out;
}
if (btrfs_fs_incompat(fs_info, MIXED_GROUPS)) {
btrfs_err(fs_info, "zoned: mixed block groups not supported");
ret = -EINVAL;
goto out;
}
fs_info->zone_size = zone_size;
fs_info->max_zone_append_size = max_zone_append_size;
/*
* Check mount options here, because we might change fs_info->zoned
* from fs_info->zone_size.
*/
ret = btrfs_check_mountopts_zoned(fs_info);
if (ret)
goto out;
btrfs_info(fs_info, "zoned mode enabled with zone size %llu", zone_size);
out:
return ret;
}
btrfs: disallow space_cache in ZONED mode As updates to the space cache v1 are in-place, the space cache cannot be located over sequential zones and there is no guarantees that the device will have enough conventional zones to store this cache. Resolve this problem by disabling completely the space cache v1. This does not introduce any problems with sequential block groups: all the free space is located after the allocation pointer and no free space before the pointer. There is no need to have such cache. Note: we can technically use free-space-tree (space cache v2) on ZONED mode. But, since ZONED mode now always allocates extents in a block group sequentially regardless of underlying device zone type, it's no use to enable and maintain the tree. For the same reason, NODATACOW is also disabled. In summary, ZONED will disable: | Disabled features | Reason | |-------------------+-----------------------------------------------------| | RAID/DUP | Cannot handle two zone append writes to different | | | zones | |-------------------+-----------------------------------------------------| | space_cache (v1) | In-place updating | | NODATACOW | In-place updating | |-------------------+-----------------------------------------------------| | fallocate | Reserved extent will be a write hole | |-------------------+-----------------------------------------------------| | MIXED_BG | Allocated metadata region will be write holes for | | | data writes | Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-11-10 11:26:10 +00:00
int btrfs_check_mountopts_zoned(struct btrfs_fs_info *info)
{
if (!btrfs_is_zoned(info))
return 0;
/*
* Space cache writing is not COWed. Disable that to avoid write errors
* in sequential zones.
*/
if (btrfs_test_opt(info, SPACE_CACHE)) {
btrfs_err(info, "zoned: space cache v1 is not supported");
return -EINVAL;
}
if (btrfs_test_opt(info, NODATACOW)) {
btrfs_err(info, "zoned: NODATACOW not supported");
return -EINVAL;
}
btrfs: disallow space_cache in ZONED mode As updates to the space cache v1 are in-place, the space cache cannot be located over sequential zones and there is no guarantees that the device will have enough conventional zones to store this cache. Resolve this problem by disabling completely the space cache v1. This does not introduce any problems with sequential block groups: all the free space is located after the allocation pointer and no free space before the pointer. There is no need to have such cache. Note: we can technically use free-space-tree (space cache v2) on ZONED mode. But, since ZONED mode now always allocates extents in a block group sequentially regardless of underlying device zone type, it's no use to enable and maintain the tree. For the same reason, NODATACOW is also disabled. In summary, ZONED will disable: | Disabled features | Reason | |-------------------+-----------------------------------------------------| | RAID/DUP | Cannot handle two zone append writes to different | | | zones | |-------------------+-----------------------------------------------------| | space_cache (v1) | In-place updating | | NODATACOW | In-place updating | |-------------------+-----------------------------------------------------| | fallocate | Reserved extent will be a write hole | |-------------------+-----------------------------------------------------| | MIXED_BG | Allocated metadata region will be write holes for | | | data writes | Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-11-10 11:26:10 +00:00
return 0;
}
btrfs: implement log-structured superblock for ZONED mode Superblock (and its copies) is the only data structure in btrfs which has a fixed location on a device. Since we cannot overwrite in a sequential write required zone, we cannot place superblock in the zone. One easy solution is limiting superblock and copies to be placed only in conventional zones. However, this method has two downsides: one is reduced number of superblock copies. The location of the second copy of superblock is 256GB, which is in a sequential write required zone on typical devices in the market today. So, the number of superblock and copies is limited to be two. Second downside is that we cannot support devices which have no conventional zones at all. To solve these two problems, we employ superblock log writing. It uses two adjacent zones as a circular buffer to write updated superblocks. Once the first zone is filled up, start writing into the second one. Then, when both zones are filled up and before starting to write to the first zone again, it reset the first zone. We can determine the position of the latest superblock by reading write pointer information from a device. One corner case is when both zones are full. For this situation, we read out the last superblock of each zone, and compare them to determine which zone is older. The following zones are reserved as the circular buffer on ZONED btrfs. - The primary superblock: zones 0 and 1 - The first copy: zones 16 and 17 - The second copy: zones 1024 or zone at 256GB which is minimum, and next to it If these reserved zones are conventional, superblock is written fixed at the start of the zone without logging. Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-11-10 11:26:14 +00:00
static int sb_log_location(struct block_device *bdev, struct blk_zone *zones,
int rw, u64 *bytenr_ret)
{
u64 wp;
int ret;
if (zones[0].type == BLK_ZONE_TYPE_CONVENTIONAL) {
*bytenr_ret = zones[0].start << SECTOR_SHIFT;
return 0;
}
ret = sb_write_pointer(bdev, zones, &wp);
if (ret != -ENOENT && ret < 0)
return ret;
if (rw == WRITE) {
struct blk_zone *reset = NULL;
if (wp == zones[0].start << SECTOR_SHIFT)
reset = &zones[0];
else if (wp == zones[1].start << SECTOR_SHIFT)
reset = &zones[1];
if (reset && reset->cond != BLK_ZONE_COND_EMPTY) {
ASSERT(reset->cond == BLK_ZONE_COND_FULL);
ret = blkdev_zone_mgmt(bdev, REQ_OP_ZONE_RESET,
reset->start, reset->len,
GFP_NOFS);
if (ret)
return ret;
reset->cond = BLK_ZONE_COND_EMPTY;
reset->wp = reset->start;
}
} else if (ret != -ENOENT) {
/* For READ, we want the precious one */
if (wp == zones[0].start << SECTOR_SHIFT)
wp = (zones[1].start + zones[1].len) << SECTOR_SHIFT;
wp -= BTRFS_SUPER_INFO_SIZE;
}
*bytenr_ret = wp;
return 0;
}
int btrfs_sb_log_location_bdev(struct block_device *bdev, int mirror, int rw,
u64 *bytenr_ret)
{
struct blk_zone zones[BTRFS_NR_SB_LOG_ZONES];
unsigned int zone_sectors;
u32 sb_zone;
int ret;
u8 zone_sectors_shift;
sector_t nr_sectors;
u32 nr_zones;
if (!bdev_is_zoned(bdev)) {
*bytenr_ret = btrfs_sb_offset(mirror);
return 0;
}
ASSERT(rw == READ || rw == WRITE);
zone_sectors = bdev_zone_sectors(bdev);
if (!is_power_of_2(zone_sectors))
return -EINVAL;
zone_sectors_shift = ilog2(zone_sectors);
for-5.11/block-2020-12-14 -----BEGIN PGP SIGNATURE----- iQJEBAABCAAuFiEEwPw5LcreJtl1+l5K99NY+ylx4KYFAl/Xec8QHGF4Ym9lQGtl cm5lbC5kawAKCRD301j7KXHgpoLbEACzXypgZWwMdfgRckA/Vt333rXHtbhUV+hK 2XP+P81iRvr9Esi31UPbRp82vrgcDO0cpI1QmQojS5U5TIQP88BfXptfRZZu48eb wT5RDDNQ34HItqAh/yEuYsv9yUKcxeIrB99tBVvM+4UmQg9zTdIW3mg6PvCBdbhV N38jI0tCF/PJatjfRuphT/nXonQLPWBlVDmZk06KZQFOwQe9ep1vUi1+nbiRPuo3 geFBpTh1Kp6Vl1B3n4RpECs6Y7I0RRuJdaH2sDizICla1/BW91F9fQwHimNnUxUq e1Q1kMuh6ftcQGkYlHSYcPhuv6CvorldTZCO5arPxWpcwvxriTSMRPWAgUr5pEiF fhiGhqeDu9e6vl9vS31wUD1B30hy+jFz9wyjRrDwJ3cPHH1JVBjTzvdX+cIh/1ku IbIwUMteUtvUrzqAv/DzbGhedp7xWtOFaVo8j0QFYh9zkjd6b8yDOF/yztwX2gjY Xt1cd+KpDSiN449ZRaoMI0sCJAxqzhMa6nsWlb0L7KuNyWKAbvKQBm9Rb47FLV9A Vx70KC+zkFoyw23capvIahmQazerriUJ5PGe0lVm6ROgmIFdCpXTPDjnrvq/6RZ/ GEpD7gTW9atGJ7EuEE8686sAfKD5kneChWLX5EHXf0d0AG5Mr2lKsluiGp5LpPJg Q1Xqs6xwww== =zo4w -----END PGP SIGNATURE----- Merge tag 'for-5.11/block-2020-12-14' of git://git.kernel.dk/linux-block Pull block updates from Jens Axboe: "Another series of killing more code than what is being added, again thanks to Christoph's relentless cleanups and tech debt tackling. This contains: - blk-iocost improvements (Baolin Wang) - part0 iostat fix (Jeffle Xu) - Disable iopoll for split bios (Jeffle Xu) - block tracepoint cleanups (Christoph Hellwig) - Merging of struct block_device and hd_struct (Christoph Hellwig) - Rework/cleanup of how block device sizes are updated (Christoph Hellwig) - Simplification of gendisk lookup and removal of block device aliasing (Christoph Hellwig) - Block device ioctl cleanups (Christoph Hellwig) - Removal of bdget()/blkdev_get() as exported API (Christoph Hellwig) - Disk change rework, avoid ->revalidate_disk() (Christoph Hellwig) - sbitmap improvements (Pavel Begunkov) - Hybrid polling fix (Pavel Begunkov) - bvec iteration improvements (Pavel Begunkov) - Zone revalidation fixes (Damien Le Moal) - blk-throttle limit fix (Yu Kuai) - Various little fixes" * tag 'for-5.11/block-2020-12-14' of git://git.kernel.dk/linux-block: (126 commits) blk-mq: fix msec comment from micro to milli seconds blk-mq: update arg in comment of blk_mq_map_queue blk-mq: add helper allocating tagset->tags Revert "block: Fix a lockdep complaint triggered by request queue flushing" nvme-loop: use blk_mq_hctx_set_fq_lock_class to set loop's lock class blk-mq: add new API of blk_mq_hctx_set_fq_lock_class block: disable iopoll for split bio block: Improve blk_revalidate_disk_zones() checks sbitmap: simplify wrap check sbitmap: replace CAS with atomic and sbitmap: remove swap_lock sbitmap: optimise sbitmap_deferred_clear() blk-mq: skip hybrid polling if iopoll doesn't spin blk-iocost: Factor out the base vrate change into a separate function blk-iocost: Factor out the active iocgs' state check into a separate function blk-iocost: Move the usage ratio calculation to the correct place blk-iocost: Remove unnecessary advance declaration blk-iocost: Fix some typos in comments blktrace: fix up a kerneldoc comment block: remove the request_queue to argument request based tracepoints ...
2020-12-16 20:57:51 +00:00
nr_sectors = bdev_nr_sectors(bdev);
btrfs: implement log-structured superblock for ZONED mode Superblock (and its copies) is the only data structure in btrfs which has a fixed location on a device. Since we cannot overwrite in a sequential write required zone, we cannot place superblock in the zone. One easy solution is limiting superblock and copies to be placed only in conventional zones. However, this method has two downsides: one is reduced number of superblock copies. The location of the second copy of superblock is 256GB, which is in a sequential write required zone on typical devices in the market today. So, the number of superblock and copies is limited to be two. Second downside is that we cannot support devices which have no conventional zones at all. To solve these two problems, we employ superblock log writing. It uses two adjacent zones as a circular buffer to write updated superblocks. Once the first zone is filled up, start writing into the second one. Then, when both zones are filled up and before starting to write to the first zone again, it reset the first zone. We can determine the position of the latest superblock by reading write pointer information from a device. One corner case is when both zones are full. For this situation, we read out the last superblock of each zone, and compare them to determine which zone is older. The following zones are reserved as the circular buffer on ZONED btrfs. - The primary superblock: zones 0 and 1 - The first copy: zones 16 and 17 - The second copy: zones 1024 or zone at 256GB which is minimum, and next to it If these reserved zones are conventional, superblock is written fixed at the start of the zone without logging. Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-11-10 11:26:14 +00:00
nr_zones = nr_sectors >> zone_sectors_shift;
sb_zone = sb_zone_number(zone_sectors_shift + SECTOR_SHIFT, mirror);
if (sb_zone + 1 >= nr_zones)
return -ENOENT;
ret = blkdev_report_zones(bdev, sb_zone << zone_sectors_shift,
BTRFS_NR_SB_LOG_ZONES, copy_zone_info_cb,
zones);
if (ret < 0)
return ret;
if (ret != BTRFS_NR_SB_LOG_ZONES)
return -EIO;
return sb_log_location(bdev, zones, rw, bytenr_ret);
}
int btrfs_sb_log_location(struct btrfs_device *device, int mirror, int rw,
u64 *bytenr_ret)
{
struct btrfs_zoned_device_info *zinfo = device->zone_info;
u32 zone_num;
/*
* For a zoned filesystem on a non-zoned block device, use the same
* super block locations as regular filesystem. Doing so, the super
* block can always be retrieved and the zoned flag of the volume
* detected from the super block information.
*/
if (!bdev_is_zoned(device->bdev)) {
btrfs: implement log-structured superblock for ZONED mode Superblock (and its copies) is the only data structure in btrfs which has a fixed location on a device. Since we cannot overwrite in a sequential write required zone, we cannot place superblock in the zone. One easy solution is limiting superblock and copies to be placed only in conventional zones. However, this method has two downsides: one is reduced number of superblock copies. The location of the second copy of superblock is 256GB, which is in a sequential write required zone on typical devices in the market today. So, the number of superblock and copies is limited to be two. Second downside is that we cannot support devices which have no conventional zones at all. To solve these two problems, we employ superblock log writing. It uses two adjacent zones as a circular buffer to write updated superblocks. Once the first zone is filled up, start writing into the second one. Then, when both zones are filled up and before starting to write to the first zone again, it reset the first zone. We can determine the position of the latest superblock by reading write pointer information from a device. One corner case is when both zones are full. For this situation, we read out the last superblock of each zone, and compare them to determine which zone is older. The following zones are reserved as the circular buffer on ZONED btrfs. - The primary superblock: zones 0 and 1 - The first copy: zones 16 and 17 - The second copy: zones 1024 or zone at 256GB which is minimum, and next to it If these reserved zones are conventional, superblock is written fixed at the start of the zone without logging. Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-11-10 11:26:14 +00:00
*bytenr_ret = btrfs_sb_offset(mirror);
return 0;
}
zone_num = sb_zone_number(zinfo->zone_size_shift, mirror);
if (zone_num + 1 >= zinfo->nr_zones)
return -ENOENT;
return sb_log_location(device->bdev,
&zinfo->sb_zones[BTRFS_NR_SB_LOG_ZONES * mirror],
rw, bytenr_ret);
}
static inline bool is_sb_log_zone(struct btrfs_zoned_device_info *zinfo,
int mirror)
{
u32 zone_num;
if (!zinfo)
return false;
zone_num = sb_zone_number(zinfo->zone_size_shift, mirror);
if (zone_num + 1 >= zinfo->nr_zones)
return false;
if (!test_bit(zone_num, zinfo->seq_zones))
return false;
return true;
}
void btrfs_advance_sb_log(struct btrfs_device *device, int mirror)
{
struct btrfs_zoned_device_info *zinfo = device->zone_info;
struct blk_zone *zone;
if (!is_sb_log_zone(zinfo, mirror))
return;
zone = &zinfo->sb_zones[BTRFS_NR_SB_LOG_ZONES * mirror];
if (zone->cond != BLK_ZONE_COND_FULL) {
if (zone->cond == BLK_ZONE_COND_EMPTY)
zone->cond = BLK_ZONE_COND_IMP_OPEN;
zone->wp += (BTRFS_SUPER_INFO_SIZE >> SECTOR_SHIFT);
if (zone->wp == zone->start + zone->len)
zone->cond = BLK_ZONE_COND_FULL;
return;
}
zone++;
ASSERT(zone->cond != BLK_ZONE_COND_FULL);
if (zone->cond == BLK_ZONE_COND_EMPTY)
zone->cond = BLK_ZONE_COND_IMP_OPEN;
zone->wp += (BTRFS_SUPER_INFO_SIZE >> SECTOR_SHIFT);
if (zone->wp == zone->start + zone->len)
zone->cond = BLK_ZONE_COND_FULL;
}
int btrfs_reset_sb_log_zones(struct block_device *bdev, int mirror)
{
sector_t zone_sectors;
sector_t nr_sectors;
u8 zone_sectors_shift;
u32 sb_zone;
u32 nr_zones;
zone_sectors = bdev_zone_sectors(bdev);
zone_sectors_shift = ilog2(zone_sectors);
for-5.11/block-2020-12-14 -----BEGIN PGP SIGNATURE----- iQJEBAABCAAuFiEEwPw5LcreJtl1+l5K99NY+ylx4KYFAl/Xec8QHGF4Ym9lQGtl cm5lbC5kawAKCRD301j7KXHgpoLbEACzXypgZWwMdfgRckA/Vt333rXHtbhUV+hK 2XP+P81iRvr9Esi31UPbRp82vrgcDO0cpI1QmQojS5U5TIQP88BfXptfRZZu48eb wT5RDDNQ34HItqAh/yEuYsv9yUKcxeIrB99tBVvM+4UmQg9zTdIW3mg6PvCBdbhV N38jI0tCF/PJatjfRuphT/nXonQLPWBlVDmZk06KZQFOwQe9ep1vUi1+nbiRPuo3 geFBpTh1Kp6Vl1B3n4RpECs6Y7I0RRuJdaH2sDizICla1/BW91F9fQwHimNnUxUq e1Q1kMuh6ftcQGkYlHSYcPhuv6CvorldTZCO5arPxWpcwvxriTSMRPWAgUr5pEiF fhiGhqeDu9e6vl9vS31wUD1B30hy+jFz9wyjRrDwJ3cPHH1JVBjTzvdX+cIh/1ku IbIwUMteUtvUrzqAv/DzbGhedp7xWtOFaVo8j0QFYh9zkjd6b8yDOF/yztwX2gjY Xt1cd+KpDSiN449ZRaoMI0sCJAxqzhMa6nsWlb0L7KuNyWKAbvKQBm9Rb47FLV9A Vx70KC+zkFoyw23capvIahmQazerriUJ5PGe0lVm6ROgmIFdCpXTPDjnrvq/6RZ/ GEpD7gTW9atGJ7EuEE8686sAfKD5kneChWLX5EHXf0d0AG5Mr2lKsluiGp5LpPJg Q1Xqs6xwww== =zo4w -----END PGP SIGNATURE----- Merge tag 'for-5.11/block-2020-12-14' of git://git.kernel.dk/linux-block Pull block updates from Jens Axboe: "Another series of killing more code than what is being added, again thanks to Christoph's relentless cleanups and tech debt tackling. This contains: - blk-iocost improvements (Baolin Wang) - part0 iostat fix (Jeffle Xu) - Disable iopoll for split bios (Jeffle Xu) - block tracepoint cleanups (Christoph Hellwig) - Merging of struct block_device and hd_struct (Christoph Hellwig) - Rework/cleanup of how block device sizes are updated (Christoph Hellwig) - Simplification of gendisk lookup and removal of block device aliasing (Christoph Hellwig) - Block device ioctl cleanups (Christoph Hellwig) - Removal of bdget()/blkdev_get() as exported API (Christoph Hellwig) - Disk change rework, avoid ->revalidate_disk() (Christoph Hellwig) - sbitmap improvements (Pavel Begunkov) - Hybrid polling fix (Pavel Begunkov) - bvec iteration improvements (Pavel Begunkov) - Zone revalidation fixes (Damien Le Moal) - blk-throttle limit fix (Yu Kuai) - Various little fixes" * tag 'for-5.11/block-2020-12-14' of git://git.kernel.dk/linux-block: (126 commits) blk-mq: fix msec comment from micro to milli seconds blk-mq: update arg in comment of blk_mq_map_queue blk-mq: add helper allocating tagset->tags Revert "block: Fix a lockdep complaint triggered by request queue flushing" nvme-loop: use blk_mq_hctx_set_fq_lock_class to set loop's lock class blk-mq: add new API of blk_mq_hctx_set_fq_lock_class block: disable iopoll for split bio block: Improve blk_revalidate_disk_zones() checks sbitmap: simplify wrap check sbitmap: replace CAS with atomic and sbitmap: remove swap_lock sbitmap: optimise sbitmap_deferred_clear() blk-mq: skip hybrid polling if iopoll doesn't spin blk-iocost: Factor out the base vrate change into a separate function blk-iocost: Factor out the active iocgs' state check into a separate function blk-iocost: Move the usage ratio calculation to the correct place blk-iocost: Remove unnecessary advance declaration blk-iocost: Fix some typos in comments blktrace: fix up a kerneldoc comment block: remove the request_queue to argument request based tracepoints ...
2020-12-16 20:57:51 +00:00
nr_sectors = bdev_nr_sectors(bdev);
btrfs: implement log-structured superblock for ZONED mode Superblock (and its copies) is the only data structure in btrfs which has a fixed location on a device. Since we cannot overwrite in a sequential write required zone, we cannot place superblock in the zone. One easy solution is limiting superblock and copies to be placed only in conventional zones. However, this method has two downsides: one is reduced number of superblock copies. The location of the second copy of superblock is 256GB, which is in a sequential write required zone on typical devices in the market today. So, the number of superblock and copies is limited to be two. Second downside is that we cannot support devices which have no conventional zones at all. To solve these two problems, we employ superblock log writing. It uses two adjacent zones as a circular buffer to write updated superblocks. Once the first zone is filled up, start writing into the second one. Then, when both zones are filled up and before starting to write to the first zone again, it reset the first zone. We can determine the position of the latest superblock by reading write pointer information from a device. One corner case is when both zones are full. For this situation, we read out the last superblock of each zone, and compare them to determine which zone is older. The following zones are reserved as the circular buffer on ZONED btrfs. - The primary superblock: zones 0 and 1 - The first copy: zones 16 and 17 - The second copy: zones 1024 or zone at 256GB which is minimum, and next to it If these reserved zones are conventional, superblock is written fixed at the start of the zone without logging. Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-11-10 11:26:14 +00:00
nr_zones = nr_sectors >> zone_sectors_shift;
sb_zone = sb_zone_number(zone_sectors_shift + SECTOR_SHIFT, mirror);
if (sb_zone + 1 >= nr_zones)
return -ENOENT;
return blkdev_zone_mgmt(bdev, REQ_OP_ZONE_RESET,
sb_zone << zone_sectors_shift,
zone_sectors * BTRFS_NR_SB_LOG_ZONES, GFP_NOFS);
}