linux/fs
Filipe Manana 4bb59055bc btrfs: avoid unnecessary btree search restarts when reading node
When reading a btree node, at read_block_for_search(), if we don't find
the node's (or leaf) extent buffer in the cache, we will read it from
disk. Since that requires waiting on IO, we release all upper level nodes
from our path before reading the target node/leaf, and then return -EAGAIN
to the caller, which will make the caller restart the while btree search.

However we are causing the restart of btree search even for cases where
it is not necessary:

1) We have a path with ->skip_locking set to true, typically when doing
   a search on a commit root, so we are never holding locks on any node;

2) We are doing a read search (the "ins_len" argument passed to
   btrfs_search_slot() is 0), or we are doing a search to modify an
   existing key (the "cow" argument passed to btrfs_search_slot() has
   a value of 1 and "ins_len" is 0), in which case we never hold locks
   for upper level nodes;

3) We are doing a search to insert or delete a key, in which case we may
   or may not have upper level nodes locked. That depends on the current
   minimum write lock levels at btrfs_search_slot(), if we had to split
   or merge parent nodes, if we had to COW upper level nodes and if
   we ever visited slot 0 of an upper level node. It's still common to
   not have upper level nodes locked, but our current node must be at
   least at level 1, for insertions, or at least at level 2 for deletions.
   In these cases when we have locks on upper level nodes, they are always
   write locks.

These cases where we are not holding locks on upper level nodes far
outweigh the cases where we are holding locks, so it's completely wasteful
to retry the whole search when we have no upper nodes locked.

So change the logic to not return -EAGAIN, and make the caller retry the
search, when we don't have the parent node locked - when it's not locked
it means no other upper level nodes are locked as well.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-05-16 17:03:06 +02:00
..
9p Netfs prep for write helpers 2022-03-31 15:49:36 -07:00
adfs Filesystem folio changes for 5.18 2022-03-22 18:26:56 -07:00
affs Filesystem folio changes for 5.18 2022-03-22 18:26:56 -07:00
afs fscache: Remove the cookie parameter from fscache_clear_page_bits() 2022-04-08 23:54:37 +01:00
autofs
befs fs: allocate inode by using alloc_inode_sb() 2022-03-22 15:57:03 -07:00
bfs Filesystem folio changes for 5.18 2022-03-22 18:26:56 -07:00
btrfs btrfs: avoid unnecessary btree search restarts when reading node 2022-05-16 17:03:06 +02:00
cachefiles cachefiles: Fix KASAN slab-out-of-bounds in cachefiles_set_volume_xattr 2022-04-08 23:32:40 +01:00
ceph ceph: check folio PG_private bit instead of folio->private 2022-05-10 09:48:31 +02:00
cifs cifs: destage any unwritten data to the server before calling copychunk_write 2022-04-20 22:54:54 -05:00
coda Folio changes for 5.18 2022-03-22 17:03:12 -07:00
configfs configfs: fix a race in configfs_{,un}register_subsystem() 2022-02-22 18:30:28 +01:00
cramfs
crypto fs: Remove ->readpages address space operation 2022-04-01 13:45:33 -04:00
debugfs debugfs: Document that debugfs_create functions need not be error checked 2022-02-25 11:56:13 +01:00
devpts fsnotify: fix fsnotify hooks in pseudo filesystems 2022-01-24 14:17:02 +01:00
dlm driver core changes for 5.17-rc1 2022-01-12 11:11:34 -08:00
ecryptfs Filesystem folio changes for 5.18 2022-03-22 18:26:56 -07:00
efivarfs
efs fs: allocate inode by using alloc_inode_sb() 2022-03-22 15:57:03 -07:00
erofs erofs: fix use-after-free of on-stack io[] 2022-04-15 23:51:43 +08:00
exfat Description for this pull request: 2022-04-01 14:20:24 -07:00
exportfs
ext2 \n 2022-03-25 17:38:15 -07:00
ext4 Fix some syzbot-detected bugs, as well as other bugs found by I/O 2022-04-22 18:18:27 -07:00
f2fs f2fs: should not truncate blocks during roll-forward recovery 2022-04-21 18:57:09 -07:00
fat Merge branch 'akpm' (patches from Andrew) 2022-03-24 14:14:07 -07:00
freevxfs fs: allocate inode by using alloc_inode_sb() 2022-03-22 15:57:03 -07:00
fscache fscache: remove FSCACHE_OLD_API Kconfig option 2022-04-08 23:54:37 +01:00
fuse fs: Remove ->readpages address space operation 2022-04-01 13:45:33 -04:00
gfs2 gfs2: Stop using glock holder auto-demotion for now 2022-05-13 22:32:52 +02:00
hfs Filesystem folio changes for 5.18 2022-03-22 18:26:56 -07:00
hfsplus Filesystem folio changes for 5.18 2022-03-22 18:26:56 -07:00
hostfs Filesystem folio changes for 5.18 2022-03-22 18:26:56 -07:00
hpfs Filesystem folio changes for 5.18 2022-03-22 18:26:56 -07:00
hugetlbfs mm, hugetlb: allow for "high" userspace addresses 2022-04-21 20:01:09 -07:00
iomap iomap: Simplify is_partially_uptodate a little 2022-04-01 14:40:43 -04:00
isofs fs: allocate inode by using alloc_inode_sb() 2022-03-22 15:57:03 -07:00
jbd2 Fix some syzbot-detected bugs, as well as other bugs found by I/O 2022-04-22 18:18:27 -07:00
jffs2 This pull request contains fixes for JFFS2, UBI and UBIFS 2022-03-31 16:09:41 -07:00
jfs A couple bug fixes 2022-03-29 18:17:30 -07:00
kernfs kernfs: fix NULL dereferencing in kernfs_remove 2022-04-27 19:32:07 +02:00
ksmbd ksmbd: set fixed sector size to FS_SECTOR_SIZE_INFORMATION 2022-04-14 20:56:13 -05:00
lockd NFSD: Move svc_serv_ops::svo_function into struct svc_serv 2022-02-28 10:26:40 -05:00
minix Merge branch 'akpm' (patches from Andrew) 2022-03-24 14:14:07 -07:00
netfs netfs: Split some core bits out into their own file 2022-03-18 09:29:05 +00:00
nfs nfs: fix broken handling of the softreval mount option 2022-05-09 13:02:54 -04:00
nfs_common
nfsd NFSD bug fixes for 5.18-rc: 2022-04-12 14:23:19 -10:00
nilfs2 nilfs2: get rid of nilfs_mapping_init() 2022-04-01 11:46:09 -07:00
nls
notify fanotify: do not allow setting dirent events in mask of non-dir 2022-05-09 11:49:09 +02:00
ntfs ntfs: Correct mark_ntfs_record_dirty() folio conversion 2022-04-01 14:40:44 -04:00
ntfs3 Filesystem folio changes for 5.18 2022-03-22 18:26:56 -07:00
ocfs2 ocfs2: fix crash when mount with quota enabled 2022-04-01 11:46:09 -07:00
omfs fs: Convert __set_page_dirty_buffers to block_dirty_folio 2022-03-16 13:37:04 -04:00
openpromfs fs: allocate inode by using alloc_inode_sb() 2022-03-22 15:57:03 -07:00
orangefs Filesystem folio changes for 5.18 2022-03-22 18:26:56 -07:00
overlayfs fs: allocate inode by using alloc_inode_sb() 2022-03-22 15:57:03 -07:00
proc procfs: prevent unprivileged processes accessing fdinfo dir 2022-05-09 17:34:28 -07:00
pstore pstore: Don't use semaphores in always-atomic-context code 2022-03-15 11:08:23 -07:00
qnx4 fs: allocate inode by using alloc_inode_sb() 2022-03-22 15:57:03 -07:00
qnx6 fs: allocate inode by using alloc_inode_sb() 2022-03-22 15:57:03 -07:00
quota quota: make dquot_quota_sync return errors from ->sync_fs 2022-01-30 08:59:47 -08:00
ramfs
reiserfs \n 2022-03-25 17:38:15 -07:00
romfs fs: allocate inode by using alloc_inode_sb() 2022-03-22 15:57:03 -07:00
smbfs_common smb3: fix ksmbd bigendian bug in oplock break, and move its struct to smbfs_common 2022-03-31 09:38:53 -05:00
squashfs Merge branch 'akpm' (patches from Andrew) 2022-03-22 16:11:53 -07:00
sysfs kobject: kobj_type: remove default_attrs 2022-04-05 15:39:19 +02:00
sysv Filesystem folio changes for 5.18 2022-03-22 18:26:56 -07:00
tracefs tracefs: Set the group ownership in apply_options() not parse_options() 2022-02-25 21:05:04 -05:00
ubifs This pull request contains fixes for JFFS2, UBI and UBIFS 2022-03-31 16:09:41 -07:00
udf udf: Avoid using stale lengthOfImpUse 2022-05-10 13:30:32 +02:00
ufs Filesystem folio changes for 5.18 2022-03-22 18:26:56 -07:00
unicode kbuild: unify cmd_copy and cmd_shipped 2022-02-14 10:37:32 +09:00
vboxsf Filesystem folio changes for 5.18 2022-03-22 18:26:56 -07:00
verity fs: Remove ->readpages address space operation 2022-04-01 13:45:33 -04:00
xfs xfs: reorder iunlink remove operation in xfs_ifree 2022-04-21 08:45:16 +10:00
zonefs zonefs: Fix management of open zones 2022-04-21 08:39:20 +09:00
aio.c Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2022-04-01 19:57:03 -07:00
anon_inodes.c
attr.c
bad_inode.c
binfmt_aout.c
binfmt_elf_fdpic.c coredump: Snapshot the vmas in do_coredump 2022-03-08 12:55:29 -06:00
binfmt_elf_test.c binfmt_elf: Introduce KUnit test 2022-03-03 20:38:56 -08:00
binfmt_elf.c revert "fs/binfmt_elf: use PT_LOAD p_align values for static PIE" 2022-04-15 14:49:56 -07:00
binfmt_flat.c coredump: Don't compile flat_core_dump when coredumps are disabled 2022-03-09 10:37:07 -06:00
binfmt_misc.c Fix regression due to "fs: move binfmt_misc sysctl to its own file" 2022-02-09 09:50:02 -08:00
binfmt_script.c
buffer.c filemap: Remove AOP_FLAG_CONT_EXPAND 2022-04-01 14:40:44 -04:00
char_dev.c
compat_binfmt_elf.c binfmt_elf: Introduce KUnit test 2022-03-03 20:38:56 -08:00
coredump.c ptrace: Cleanups for v5.18 2022-03-28 17:29:53 -07:00
d_path.c
dax.c dax for 5.18 2022-03-24 18:12:09 -07:00
dcache.c mm: dcache: use kmem_cache_alloc_lru() to allocate dentry 2022-03-22 15:57:03 -07:00
direct-io.c block: remove the per-bio/request write hint 2022-03-07 12:45:57 -07:00
drop_caches.c
eventfd.c
eventpoll.c eventpoll: simplify sysctl declaration with register_sysctl() 2022-01-22 08:33:35 +02:00
exec.c ptrace: Cleanups for v5.18 2022-03-28 17:29:53 -07:00
fcntl.c fs: remove fs.f_write_hint 2022-03-08 17:55:03 -07:00
fhandle.c
file_table.c SUNRPC: Ensure we flush any closed sockets before xs_xprt_free() 2022-04-07 16:19:47 -04:00
file.c fs: fix fd table size alignment properly 2022-03-29 23:29:18 -07:00
filesystems.c
fs_context.c vfs: fs_context: fix up param length parsing in legacy_parse_param 2022-01-18 09:23:19 +02:00
fs_parser.c
fs_pin.c
fs_struct.c
fs_types.c
fs-writeback.c writeback: Avoid skipping inode writeback 2022-05-10 12:04:21 +02:00
fsopen.c
init.c
inode.c fs: introduce alloc_inode_sb() to allocate filesystems specific inode 2022-03-22 15:57:03 -07:00
internal.h Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2022-04-01 19:57:03 -07:00
io_uring.c io_uring: assign non-fixed early for async work 2022-05-02 08:09:39 -06:00
io-wq.c ptrace: Cleanups for v5.18 2022-03-28 17:29:53 -07:00
io-wq.h io_uring: stop using io_wq_work as an fd placeholder 2022-04-11 17:06:20 -06:00
ioctl.c Fixes for 5.18-rc1: 2022-04-01 19:35:56 -07:00
Kconfig Folio changes for 5.18 2022-03-22 17:03:12 -07:00
Kconfig.binfmt execve updates for v5.18-rc1 2022-03-21 19:16:02 -07:00
kernel_read_file.c
libfs.c fs: Convert __set_page_dirty_no_writeback to noop_dirty_folio 2022-03-16 13:37:05 -04:00
locks.c fs: move locking sysctls where they are used 2022-01-22 08:33:36 +02:00
Makefile Fix from Christoph Hellwig merging the CONFIG_UNICODE_UTF8_DATA into the 2022-02-01 11:13:24 -08:00
mbcache.c
mount.h
mpage.c for-5.18/alloc-cleanups-2022-03-25 2022-03-26 11:59:30 -07:00
namei.c VFS: filename_create(): fix incorrect intent. 2022-04-14 15:53:43 -07:00
namespace.c fs: unset MNT_WRITE_HOLD on failure 2022-04-21 17:57:37 +02:00
no-block.c
nsfs.c
open.c fs: remove fs.f_write_hint 2022-03-08 17:55:03 -07:00
pipe.c Revert "fs/pipe: use kvcalloc to allocate a pipe_buffer array" 2022-04-20 12:07:53 -07:00
pnode.c
pnode.h
posix_acl.c fs: fix acl translation 2022-04-19 10:19:02 -07:00
proc_namespace.c
read_write.c Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2022-04-01 19:57:03 -07:00
readdir.c
remap_range.c Filesystem folio changes for 5.18 2022-03-22 18:26:56 -07:00
select.c select: Fix indefinitely sleeping task in poll_schedule_timeout() 2022-01-11 09:03:05 -08:00
seq_file.c seq_file: fix NULL pointer arithmetic warning 2022-02-01 11:31:55 -05:00
signalfd.c Merge branch 'signal-for-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2022-01-17 05:49:30 +02:00
splice.c mm: Convert remove_mapping() to take a folio 2022-03-21 12:59:01 -04:00
stack.c
stat.c stat: fix inconsistency between struct stat and struct compat_stat 2022-04-12 13:35:08 -10:00
statfs.c
super.c vfs: make freeze_super abort when sync_filesystem returns error 2022-01-30 08:59:47 -08:00
sync.c vfs: make sync_filesystem return errors from ->sync_fs 2022-01-30 08:59:47 -08:00
sysctls.c fs: move namespace sysctls and declare fs base directory 2022-01-22 08:33:36 +02:00
timerfd.c
userfaultfd.c userfaultfd: provide unmasked address on page-fault 2022-03-22 15:57:08 -07:00
utimes.c
xattr.c fs: fix acl translation 2022-04-19 10:19:02 -07:00