linux/fs/btrfs
David Sterba 0b5485391d btrfs: locking: use atomic for DREW lock writers
The DREW lock uses percpu variable to track lock counters and for that
it needs to allocate the structure. In btrfs_read_tree_root() or
btrfs_init_fs_root() this may add another error case or requires the
NOFS scope protection.

One way is to preallocate the structure as was suggested in
https://lore.kernel.org/linux-btrfs/20221214021125.28289-1-robbieko@synology.com/

We may avoid the allocation altogether if we don't use the percpu
variables but an atomic for the writer counter. This should not make any
difference, the DREW lock is used for truncate and NOCOW writes along
with other IO operations.

The percpu counter for writers has been there since the original commit
8257b2dc3c "Btrfs: introduce btrfs_{start, end}_nocow_write() for
each subvolume". The reason could be to avoid hammering the same
cacheline from all the readers but then the writers do that anyway.

Signed-off-by: David Sterba <dsterba@suse.com>
2023-04-17 18:01:17 +02:00
..
tests btrfs: replace map_lookup->stripe_len by BTRFS_STRIPE_LEN 2023-04-17 18:01:14 +02:00
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 fs: port acl to mnt_idmap 2023-01-19 09:24:28 +01:00
acl.h fs: port ->set_acl() to pass mnt_idmap 2023-01-19 09:24:27 +01:00
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: ignore fiemap path cache when there are multiple paths for a node 2023-03-29 01:16:23 +02:00
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: fix unnecessary increment of read error stat on write error 2023-03-06 19:28:19 +01:00
bio.h btrfs: remove the fs_info argument to btrfs_submit_bio 2023-02-15 19:38:53 +01:00
block-group.c btrfs: reduce div64 calls by limiting the number of stripes of a chunk to u32 2023-04-17 18:01:14 +02:00
block-group.h btrfs: remove the bdev argument to btrfs_rmap_block 2023-02-15 19:38:55 +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 for-6.3-tag 2023-02-20 12:54:27 -08:00
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: fold finish_compressed_bio_write into btrfs_finish_compressed_write_work 2023-04-17 18:01:15 +02:00
compression.h btrfs: embed a btrfs_bio into struct compressed_bio 2023-04-17 18:01:14 +02:00
ctree.c btrfs: open code btrfs_bin_search() 2023-04-17 18:01:15 +02:00
ctree.h btrfs: open code btrfs_bin_search() 2023-04-17 18:01:15 +02:00
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: handle btrfs_del_item errors in __btrfs_update_delayed_inode 2023-03-06 19:28:19 +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: hold block group refcount during async discard 2023-02-15 19:38:50 +01:00
discard.h btrfs: cleanup btrfs_discard_update_discardable usage 2020-12-08 15:54:02 +01:00
disk-io.c btrfs: locking: use atomic for DREW lock writers 2023-04-17 18:01:17 +02:00
disk-io.h btrfs: rename btrfs_clean_tree_block to btrfs_clear_buffer_dirty 2023-02-15 19:38:53 +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.c btrfs: sink calc_bio_boundaries into its only caller 2023-04-17 18:01:16 +02:00
extent_io.h btrfs: combine btrfs_clear_buffer_dirty and clear_extent_buffer_dirty 2023-02-15 19:38:54 +01:00
extent_map.c btrfs: fix extent map logging bit not cleared for split maps after dropping range 2023-03-06 19:28:19 +01:00
extent_map.h btrfs: remove no longer used btrfs_next_extent_map() 2022-12-05 18:00:56 +01:00
extent-io-tree.c btrfs: fix spelling mistakes found using codespell 2023-02-15 19:38:50 +01:00
extent-io-tree.h btrfs: remove the io_failure_record infrastructure 2023-02-15 19:38:51 +01:00
extent-tree.c btrfs: abort the transaction if we get an error during snapshot drop 2023-04-17 18:01:13 +02:00
extent-tree.h btrfs: introduce size class to block group allocator 2023-02-13 17:50:34 +01:00
file-item.c btrfs: cleanup the main loop in btrfs_lookup_bio_sums 2023-04-17 18:01:16 +02:00
file-item.h btrfs: simplify the btrfs_csum_one_bio calling convention 2023-02-15 19:38:52 +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: zoned: count fresh BG region as zone unusable 2023-03-15 20:51:07 +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: rename btrfs_clean_tree_block to btrfs_clear_buffer_dirty 2023-02-15 19:38:53 +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: avoid repetitive define BTRFS_FEATURE_INCOMPAT_SUPP 2023-04-17 18:01:16 +02:00
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: embed a btrfs_bio into struct compressed_bio 2023-04-17 18:01:14 +02:00
ioctl.c for-6.3-rc4-tag 2023-04-02 10:57:12 -07:00
ioctl.h fs: port ->fileattr_set() to pass mnt_idmap 2023-01-19 09:24:27 +01:00
Kconfig fs/btrfs: Remove "select SRCU" 2023-02-02 16:26:06 -08:00
locking.c btrfs: locking: use atomic for DREW lock writers 2023-04-17 18:01:17 +02:00
locking.h btrfs: locking: use atomic for DREW lock writers 2023-04-17 18:01:17 +02:00
lru_cache.c btrfs: send: cache utimes operations for directories if possible 2023-02-15 19:38:50 +01:00
lru_cache.h btrfs: send: cache utimes operations for directories if possible 2023-02-15 19:38:50 +01:00
lzo.c btrfs: embed a btrfs_bio into struct compressed_bio 2023-04-17 18:01:14 +02:00
Makefile btrfs: send: genericize the backref cache to allow it to be reused 2023-02-13 17:50:35 +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: don't rely on unchanging ->bi_bdev for zone append remaps 2023-02-15 19:38:55 +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 btrfs: print the actual offset in btrfs_root_name 2021-01-07 17:25:05 +01:00
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 disable and quota assign ioctls 2023-03-28 00:46:53 +02:00
qgroup.h btrfs: sink gfp_t parameter to btrfs_qgroup_trace_extent 2022-12-05 18:00:43 +01:00
raid56.c btrfs: replace btrfs_io_context::raid_map with a fixed u64 value 2023-04-17 18:01:14 +02:00
raid56.h btrfs: fix spelling mistakes found using codespell 2023-02-15 19:38:50 +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: open code btrfs_bin_search() 2023-04-17 18:01:15 +02:00
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: remove root and csum_root arguments from scrub_simple_mirror() 2023-04-17 18:01:16 +02:00
scrub.h btrfs: move scrub prototypes into scrub.h 2022-12-05 18:00:47 +01:00
send.c btrfs: send: cache utimes operations for directories if possible 2023-02-15 19:38:50 +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: drop space_info->active_total_bytes 2023-03-15 20:51:07 +01:00
space-info.h btrfs: zoned: drop space_info->active_total_bytes 2023-03-15 20:51:07 +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: use btrfs_handle_fs_error in btrfs_fill_super 2023-04-17 18:01:12 +02:00
super.h btrfs: move super_block specific helpers into super.h 2022-12-05 18:00:47 +01:00
sysfs.c btrfs: sysfs: add size class stats 2023-03-01 19:27:20 +01:00
sysfs.h btrfs: sysfs: update fs features directory asynchronously 2023-02-13 17:50:35 +01:00
transaction.c btrfs: fix deadlock when aborting transaction during relocation with scrub 2023-03-28 00:47:00 +02:00
transaction.h btrfs: move btrfs_abort_transaction to transaction.c 2023-02-13 17:50:33 +01:00
tree-checker.c btrfs: reduce div64 calls by limiting the number of stripes of a chunk to u32 2023-04-17 18:01:14 +02:00
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: open code btrfs_bin_search() 2023-04-17 18:01:15 +02:00
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 fsverity: pass pos and size to ->write_merkle_tree_block 2023-01-01 15:46:48 -08:00
verity.h btrfs: move verity prototypes into verity.h 2022-12-05 18:00:47 +01:00
volumes.c btrfs: do not use replace target device as an extra mirror 2023-04-17 18:01:16 +02:00
volumes.h btrfs: replace btrfs_io_context::raid_map with a fixed u64 value 2023-04-17 18:01:14 +02:00
xattr.c fs: port xattr to mnt_idmap 2023-01-19 09:24:28 +01:00
xattr.h
zlib.c btrfs: zlib: zero-initialize zlib workspace 2023-01-25 20:11:08 +01:00
zoned.c btrfs: zoned: drop space_info->active_total_bytes 2023-03-15 20:51:07 +01:00
zoned.h btrfs: pass a btrfs_bio to btrfs_use_append 2023-02-15 19:38:55 +01:00
zstd.c btrfs: constify input buffer parameter in compression code 2022-12-05 18:00:55 +01:00