@@ -1223,8 +1223,8 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
block_group->space_info->total_bytes -= block_group->length;
block_group->space_info->bytes_readonly -=
(block_group->length - block_group->zone_unusable);
- block_group->space_info->bytes_zone_unusable -=
- block_group->zone_unusable;
+ btrfs_space_info_update_bytes_zone_unusable(fs_info, block_group->space_info,
+ -block_group->zone_unusable);
block_group->space_info->disk_total -= block_group->length * factor;
spin_unlock(&block_group->space_info->lock);
@@ -1396,7 +1396,8 @@ static int inc_block_group_ro(struct btrfs_block_group *cache, int force)
if (btrfs_is_zoned(cache->fs_info)) {
/* Migrate zone_unusable bytes to readonly */
sinfo->bytes_readonly += cache->zone_unusable;
- sinfo->bytes_zone_unusable -= cache->zone_unusable;
+ btrfs_space_info_update_bytes_zone_unusable(cache->fs_info, sinfo,
+ -cache->zone_unusable);
cache->zone_unusable = 0;
}
cache->ro++;
@@ -3056,9 +3057,11 @@ void btrfs_dec_block_group_ro(struct btrfs_block_group *cache)
if (btrfs_is_zoned(cache->fs_info)) {
/* Migrate zone_unusable bytes back */
cache->zone_unusable =
- (cache->alloc_offset - cache->used) +
+ (cache->alloc_offset - cache->used - cache->pinned -
+ cache->reserved) +
(cache->length - cache->zone_capacity);
- sinfo->bytes_zone_unusable += cache->zone_unusable;
+ btrfs_space_info_update_bytes_zone_unusable(cache->fs_info, sinfo,
+ cache->zone_unusable);
sinfo->bytes_readonly -= cache->zone_unusable;
}
num_bytes = cache->length - cache->reserved -
@@ -2793,7 +2793,7 @@ static int unpin_extent_range(struct btrfs_fs_info *fs_info,
readonly = true;
} else if (btrfs_is_zoned(fs_info)) {
/* Need reset before reusing in a zoned block group */
- space_info->bytes_zone_unusable += len;
+ btrfs_space_info_update_bytes_zone_unusable(fs_info, space_info, len);
readonly = true;
}
spin_unlock(&cache->lock);
@@ -2723,8 +2723,10 @@ static int __btrfs_add_free_space_zoned(struct btrfs_block_group *block_group,
* If the block group is read-only, we should account freed space into
* bytes_readonly.
*/
- if (!block_group->ro)
+ if (!block_group->ro) {
block_group->zone_unusable += to_unusable;
+ WARN_ON(block_group->zone_unusable > block_group->length);
+ }
spin_unlock(&ctl->tree_lock);
if (!used) {
spin_lock(&block_group->lock);
@@ -316,7 +316,7 @@ void btrfs_add_bg_to_space_info(struct btrfs_fs_info *info,
found->bytes_used += block_group->used;
found->disk_used += block_group->used * factor;
found->bytes_readonly += block_group->bytes_super;
- found->bytes_zone_unusable += block_group->zone_unusable;
+ btrfs_space_info_update_bytes_zone_unusable(info, found, block_group->zone_unusable);
if (block_group->length > 0)
found->full = 0;
btrfs_try_granting_tickets(info, found);
@@ -249,6 +249,7 @@ btrfs_space_info_update_##name(struct btrfs_fs_info *fs_info, \
DECLARE_SPACE_INFO_UPDATE(bytes_may_use, "space_info");
DECLARE_SPACE_INFO_UPDATE(bytes_pinned, "pinned");
+DECLARE_SPACE_INFO_UPDATE(bytes_zone_unusable, "zone_unusable");
int btrfs_init_space_info(struct btrfs_fs_info *fs_info);
void btrfs_add_bg_to_space_info(struct btrfs_fs_info *info,
@@ -2383,6 +2383,14 @@ DEFINE_EVENT(btrfs__space_info_update, update_bytes_pinned,
TP_ARGS(fs_info, sinfo, old, diff)
);
+DEFINE_EVENT(btrfs__space_info_update, update_bytes_zone_unusable,
+
+ TP_PROTO(const struct btrfs_fs_info *fs_info,
+ const struct btrfs_space_info *sinfo, u64 old, s64 diff),
+
+ TP_ARGS(fs_info, sinfo, old, diff)
+);
+
DECLARE_EVENT_CLASS(btrfs_raid56_bio,
TP_PROTO(const struct btrfs_raid_bio *rbio,
When btrfs makes a block group read-only, it adds all free regions in the BG to space_info->bytes_readonly. That free space excludes reserved and pinned regions. OTOH, when btrfs makes the BG read-write again, it moves all the unused regions into the block group's zone_unusable. That unused region includes reserved and pinned regions. As a result, it counts too much zone_unusable bytes. Fortunately (or unfortunately), having erroneous zone_unusable does not affect the calculation of space_info->bytes_readonly, because free space (num_bytes in btrfs_dec_block_group_ro) calculation is done based on the erroneous zone_unusable and it reduces the num_bytes just to cancel the error. This behavior can be easily discovered by adding a WARN_ON to check e.g, "bg->pinned > 0" in btrfs_dec_block_group_ro(), and running fstests test case like btrfs/282. Fix it by properly considering pinned and reserved in btrfs_dec_block_group_ro(). Also, add a WARN_ON and introduce btrfs_space_info_update_bytes_zone_unusable() to catch a similar mistake. Fixes: 169e0da91a21 ("btrfs: zoned: track unusable bytes for zones") CC: stable@vger.kernel.org # 5.15+ Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> --- fs/btrfs/block-group.c | 13 ++++++++----- fs/btrfs/extent-tree.c | 2 +- fs/btrfs/free-space-cache.c | 4 +++- fs/btrfs/space-info.c | 2 +- fs/btrfs/space-info.h | 1 + include/trace/events/btrfs.h | 8 ++++++++ 6 files changed, 22 insertions(+), 8 deletions(-)