linux/fs/btrfs
Qu Wenruo b7625f461d btrfs: sysfs: update fs features directory asynchronously
[BUG]
Since the introduction of per-fs feature sysfs interface
(/sys/fs/btrfs/<UUID>/features/), the content of that directory is never
updated.

Thus for the following case, that directory will not show the new
features like RAID56:

  # mkfs.btrfs -f $dev1 $dev2 $dev3
  # mount $dev1 $mnt
  # btrfs balance start -f -mconvert=raid5 $mnt
  # ls /sys/fs/btrfs/$uuid/features/
  extended_iref  free_space_tree  no_holes  skinny_metadata

While after unmount and mount, we got the correct features:

  # umount $mnt
  # mount $dev1 $mnt
  # ls /sys/fs/btrfs/$uuid/features/
  extended_iref  free_space_tree  no_holes  raid56 skinny_metadata

[CAUSE]
Because we never really try to update the content of per-fs features/
directory.

We had an attempt to update the features directory dynamically in commit
14e46e0495 ("btrfs: synchronize incompat feature bits with sysfs
files"), but unfortunately it get reverted in commit e410e34fad
("Revert "btrfs: synchronize incompat feature bits with sysfs files"").
The problem in the original patch is, in the context of
btrfs_create_chunk(), we can not afford to update the sysfs group.

The exported but never utilized function, btrfs_sysfs_feature_update()
is the leftover of such attempt.  As even if we go sysfs_update_group(),
new files will need extra memory allocation, and we have no way to
specify the sysfs update to go GFP_NOFS.

[FIX]
This patch will address the old problem by doing asynchronous sysfs
update in the cleaner thread.

This involves the following changes:

- Make __btrfs_(set|clear)_fs_(incompat|compat_ro) helpers to set
  BTRFS_FS_FEATURE_CHANGED flag when needed

- Update btrfs_sysfs_feature_update() to use sysfs_update_group()
  And drop unnecessary arguments.

- Call btrfs_sysfs_feature_update() in cleaner_kthread
  If we have the BTRFS_FS_FEATURE_CHANGED flag set.

- Wake up cleaner_kthread in btrfs_commit_transaction if we have
  BTRFS_FS_FEATURE_CHANGED flag

By this, all the previously dangerous call sites like
btrfs_create_chunk() need no new changes, as above helpers would
have already set the BTRFS_FS_FEATURE_CHANGED flag.

The real work happens at cleaner_kthread, thus we pay the cost of
delaying the update to sysfs directory, but the delayed time should be
small enough that end user can not distinguish though it might get
delayed if the cleaner thread is busy with removing subvolumes or
defrag.

CC: stable@vger.kernel.org # 4.14+
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-13 17:50:35 +01:00
..
tests btrfs: drop private_data parameter from extent_io_tree_init 2022-12-05 18:00:54 +01:00
accessors.c btrfs: add eb to btrfs_node_key_ptr_offset 2022-12-05 18:00:58 +01:00
accessors.h btrfs: add stack helpers for a few btrfs items 2022-12-05 18:00:58 +01:00
acl.c for-6.2-tag 2022-12-12 20:47:51 -08:00
acl.h for-6.2-tag 2022-12-12 20:47:51 -08:00
async-thread.c btrfs: simplify WQ_HIGHPRI handling in struct btrfs_workqueue 2022-05-16 17:03:15 +02:00
async-thread.h btrfs: remove unused typedefs get_extent_t and btrfs_work_func_t 2022-07-25 17:45:36 +02:00
backref.c btrfs: fix resolving backrefs for inline extent followed by prealloc 2022-12-20 19:43:43 +01:00
backref.h btrfs: send: skip resolution of our own backref when finding clone source 2022-12-05 18:00:50 +01:00
bio.c btrfs: handle case when repair happens with dev-replace 2023-01-03 15:53:18 +01:00
bio.h btrfs: split the bio submission path into a separate file 2022-12-05 18:00:57 +01:00
block-group.c btrfs: don't use size classes for zoned file systems 2023-02-13 17:50:34 +01:00
block-group.h btrfs: don't use size classes for zoned file systems 2023-02-13 17:50:34 +01:00
block-rsv.c btrfs: simplify percent calculation helpers, rename div_factor 2022-12-05 18:00:48 +01:00
block-rsv.h btrfs: simplify percent calculation helpers, rename div_factor 2022-12-05 18:00:48 +01:00
btrfs_inode.h btrfs: pass btrfs_inode to btrfs_add_delayed_iput 2022-12-05 18:00:55 +01:00
check-integrity.c btrfs: use btrfs_dev_name() helper to handle missing devices better 2022-12-05 18:00:57 +01:00
check-integrity.h btrfs: check-integrity: split submit_bio from btrfsic checking 2022-05-16 17:03:12 +02:00
compression.c btrfs: use PAGE_{ALIGN, ALIGNED, ALIGN_DOWN} macro 2023-02-13 17:50:34 +01:00
compression.h btrfs: constify input buffer parameter in compression code 2022-12-05 18:00:55 +01:00
ctree.c btrfs: add might_sleep() annotations 2022-12-05 18:00:59 +01:00
ctree.h fs.acl.rework.v6.2 2022-12-12 18:46:39 -08:00
defrag.c btrfs: remove the wait argument to btrfs_start_ordered_extent 2023-02-13 17:50:34 +01:00
defrag.h btrfs: move defrag related prototypes to their own header 2022-12-05 18:00:46 +01:00
delalloc-space.c btrfs: update function comments 2022-12-05 18:00:45 +01:00
delalloc-space.h btrfs: move delalloc space related prototypes to delalloc-space.h 2022-12-05 18:00:44 +01:00
delayed-inode.c btrfs: pass btrfs_inode to btrfs_inode_unlock 2022-12-05 18:00:53 +01:00
delayed-inode.h btrfs: extend btrfs_dir_item type to store encryption status 2022-12-05 18:00:43 +01:00
delayed-ref.c btrfs: directly pass in fs_info to btrfs_merge_delayed_refs 2023-02-13 17:50:33 +01:00
delayed-ref.h btrfs: directly pass in fs_info to btrfs_merge_delayed_refs 2023-02-13 17:50:33 +01:00
dev-replace.c btrfs: use btrfs_dev_name() helper to handle missing devices better 2022-12-05 18:00:57 +01:00
dev-replace.h btrfs: move dev-replace prototypes into dev-replace.h 2022-12-05 18:00:47 +01:00
dir-item.c btrfs: move dir-item prototypes into dir-item.h 2022-12-05 18:00:46 +01:00
dir-item.h btrfs: move dir-item prototypes into dir-item.h 2022-12-05 18:00:46 +01:00
discard.c btrfs: update function comments 2022-12-05 18:00:45 +01:00
discard.h
disk-io.c btrfs: sysfs: update fs features directory asynchronously 2023-02-13 17:50:35 +01:00
disk-io.h btrfs: fix compat_ro checks against remount 2023-01-03 16:22:13 +01:00
export.c btrfs: move super_block specific helpers into super.h 2022-12-05 18:00:47 +01:00
export.h btrfs: simplify generation check in btrfs_get_dentry 2022-12-05 18:00:41 +01:00
extent-io-tree.c btrfs: fix uninitialized variable warnings in __set_extent_bit and convert_extent_bit 2023-02-13 17:50:33 +01:00
extent-io-tree.h btrfs: allow passing a cached state record to count_range_bits() 2022-12-05 18:00:56 +01:00
extent-tree.c btrfs: remove duplicate include header in extent-tree.c 2023-02-13 17:50:34 +01:00
extent-tree.h btrfs: introduce size class to block group allocator 2023-02-13 17:50:34 +01:00
extent_io.c btrfs: lock the inode in shared mode before starting fiemap 2023-02-09 17:02:27 +01:00
extent_io.h btrfs: move eb offset helpers into extent_io.h 2022-12-05 18:00:58 +01:00
extent_map.c btrfs: remove no longer used btrfs_next_extent_map() 2022-12-05 18:00:56 +01:00
extent_map.h btrfs: remove no longer used btrfs_next_extent_map() 2022-12-05 18:00:56 +01:00
file-item.c btrfs: split the bio submission path into a separate file 2022-12-05 18:00:57 +01:00
file-item.h btrfs: move file_extent_item helpers into file-item.h 2022-12-05 18:00:58 +01:00
file.c btrfs: remove the wait argument to btrfs_start_ordered_extent 2023-02-13 17:50:34 +01:00
file.h btrfs: use cached state when looking for delalloc ranges with fiemap 2022-12-05 18:00:56 +01:00
free-space-cache.c btrfs: pass btrfs_inode to btrfs_add_delayed_iput 2022-12-05 18:00:55 +01:00
free-space-cache.h btrfs: convert discard stat defs to enum 2022-12-05 18:00:45 +01:00
free-space-tree.c btrfs: convert btrfs_block_group::needs_free_space to runtime flag 2022-12-05 18:00:51 +01:00
free-space-tree.h
fs.c btrfs: sysfs: update fs features directory asynchronously 2023-02-13 17:50:35 +01:00
fs.h btrfs: sysfs: update fs features directory asynchronously 2023-02-13 17:50:35 +01:00
inode-item.c btrfs: move file-item prototypes into their own header 2022-12-05 18:00:46 +01:00
inode-item.h btrfs: use struct fscrypt_str instead of struct qstr 2022-12-05 18:00:43 +01:00
inode.c btrfs: remove the wait argument to btrfs_start_ordered_extent 2023-02-13 17:50:34 +01:00
ioctl.c for-6.2-tag 2022-12-12 20:47:51 -08:00
ioctl.h btrfs: move ioctl prototypes into ioctl.h 2022-12-05 18:00:46 +01:00
Kconfig btrfs: use generic Kconfig option for 256kB page size limit 2022-01-20 08:52:55 +02:00
locking.c btrfs: move accessor helpers into accessors.h 2022-12-05 18:00:42 +01:00
locking.h btrfs: move the lockdep helpers into locking.h 2022-12-05 18:00:44 +01:00
lzo.c btrfs: use PAGE_{ALIGN, ALIGNED, ALIGN_DOWN} macro 2023-02-13 17:50:34 +01:00
Makefile btrfs: turn on -Wmaybe-uninitialized 2023-02-13 17:50:33 +01:00
messages.c btrfs: move btrfs_abort_transaction to transaction.c 2023-02-13 17:50:33 +01:00
messages.h btrfs: move btrfs_abort_transaction to transaction.c 2023-02-13 17:50:33 +01:00
misc.h btrfs: simplify percent calculation helpers, rename div_factor 2022-12-05 18:00:48 +01:00
ordered-data.c btrfs: remove the wait argument to btrfs_start_ordered_extent 2023-02-13 17:50:34 +01:00
ordered-data.h btrfs: remove the wait argument to btrfs_start_ordered_extent 2023-02-13 17:50:34 +01:00
orphan.c btrfs: move orphan prototypes into orphan.h 2022-12-05 18:00:47 +01:00
orphan.h btrfs: move orphan prototypes into orphan.h 2022-12-05 18:00:47 +01:00
print-tree.c btrfs: move struct btrfs_tree_parent_check out of disk-io.h 2022-12-05 18:00:57 +01:00
print-tree.h
props.c btrfs: move super_block specific helpers into super.h 2022-12-05 18:00:47 +01:00
props.h btrfs: make module init/exit match their sequence 2022-12-05 18:00:40 +01:00
qgroup.c btrfs: fix race between quota rescan and disable leading to NULL pointer deref 2023-01-16 19:46:54 +01:00
qgroup.h btrfs: sink gfp_t parameter to btrfs_qgroup_trace_extent 2022-12-05 18:00:43 +01:00
raid56.c btrfs: raid56: make error_bitmap update atomic 2023-01-27 14:57:10 +01:00
raid56.h btrfs: raid56: prepare data checksums for later RMW verification 2022-12-05 18:00:57 +01:00
rcu-string.h btrfs: replace strncpy() with strscpy() 2022-12-05 18:00:59 +01:00
ref-verify.c btrfs: move accessor helpers into accessors.h 2022-12-05 18:00:42 +01:00
ref-verify.h
reflink.c btrfs: pass btrfs_inode to btrfs_inode_unlock 2022-12-05 18:00:53 +01:00
reflink.h
relocation.c btrfs: use PAGE_{ALIGN, ALIGNED, ALIGN_DOWN} macro 2023-02-13 17:50:34 +01:00
relocation.h btrfs: move relocation prototypes into relocation.h 2022-12-05 18:00:47 +01:00
root-tree.c btrfs: move orphan prototypes into orphan.h 2022-12-05 18:00:47 +01:00
root-tree.h btrfs: move root tree prototypes to their own header 2022-12-05 18:00:44 +01:00
scrub.c btrfs: scrub: improve tree block error reporting 2023-02-13 17:50:34 +01:00
scrub.h btrfs: move scrub prototypes into scrub.h 2022-12-05 18:00:47 +01:00
send.c btrfs: use PAGE_{ALIGN, ALIGNED, ALIGN_DOWN} macro 2023-02-13 17:50:34 +01:00
send.h btrfs: send add define for v2 buffer size 2022-12-05 18:00:41 +01:00
space-info.c btrfs: zoned: enable metadata over-commit for non-ZNS setup 2023-01-11 20:04:25 +01:00
space-info.h btrfs: move btrfs_account_ro_block_groups_free_space into space-info.c 2022-12-05 18:00:44 +01:00
subpage.c btrfs: move the printk helpers out of ctree.h 2022-12-05 18:00:41 +01:00
subpage.h btrfs: make nodesize >= PAGE_SIZE case to reuse the non-subpage routine 2022-05-16 17:03:11 +02:00
super.c btrfs: pass find_free_extent_ctl to allocator tracepoints 2023-02-13 17:50:34 +01:00
super.h btrfs: move super_block specific helpers into super.h 2022-12-05 18:00:47 +01:00
sysfs.c btrfs: sysfs: update fs features directory asynchronously 2023-02-13 17:50:35 +01:00
sysfs.h btrfs: sysfs: update fs features directory asynchronously 2023-02-13 17:50:35 +01:00
transaction.c btrfs: sysfs: update fs features directory asynchronously 2023-02-13 17:50:35 +01:00
transaction.h btrfs: move btrfs_abort_transaction to transaction.c 2023-02-13 17:50:33 +01:00
tree-checker.c btrfs: pass the extent buffer for the btrfs_item_nr helpers 2022-12-05 18:00:58 +01:00
tree-checker.h btrfs: move struct btrfs_tree_parent_check out of disk-io.h 2022-12-05 18:00:57 +01:00
tree-log.c btrfs: use a single variable to track return value for log_dir_items() 2023-02-13 17:50:34 +01:00
tree-log.h btrfs: use a negative value for BTRFS_LOG_FORCE_COMMIT 2023-02-13 17:50:34 +01:00
tree-mod-log.c btrfs: add eb to btrfs_node_key_ptr_offset 2022-12-05 18:00:58 +01:00
tree-mod-log.h btrfs: fix SPDX comment in tree-mod-log.h 2022-12-05 18:00:48 +01:00
ulist.c btrfs: constify ulist parameter of ulist_next() 2022-12-05 18:00:50 +01:00
ulist.h btrfs: constify ulist parameter of ulist_next() 2022-12-05 18:00:50 +01:00
uuid-tree.c btrfs: move uuid tree prototypes to uuid-tree.h 2022-12-05 18:00:46 +01:00
uuid-tree.h btrfs: move uuid tree prototypes to uuid-tree.h 2022-12-05 18:00:46 +01:00
verity.c btrfs: move orphan prototypes into orphan.h 2022-12-05 18:00:47 +01:00
verity.h btrfs: move verity prototypes into verity.h 2022-12-05 18:00:47 +01:00
volumes.c btrfs: free device in btrfs_close_devices for a single device filesystem 2023-02-09 17:02:51 +01:00
volumes.h btrfs: split the bio submission path into a separate file 2022-12-05 18:00:57 +01:00
xattr.c btrfs: move dir-item prototypes into dir-item.h 2022-12-05 18:00:46 +01:00
xattr.h
zlib.c btrfs: zlib: zero-initialize zlib workspace 2023-01-25 20:11:08 +01:00
zoned.c btrfs: zoned: fix uninitialized variable warning in btrfs_get_dev_zones 2023-02-13 17:50:33 +01:00
zoned.h btrfs: move the printk helpers out of ctree.h 2022-12-05 18:00:41 +01:00
zstd.c btrfs: constify input buffer parameter in compression code 2022-12-05 18:00:55 +01:00