linux/fs
Josef Bacik ded566b463 btrfs: fix deadlock with fiemap and extent locking
commit b0ad381fa7 upstream.

While working on the patchset to remove extent locking I got a lockdep
splat with fiemap and pagefaulting with my new extent lock replacement
lock.

This deadlock exists with our normal code, we just don't have lockdep
annotations with the extent locking so we've never noticed it.

Since we're copying the fiemap extent to user space on every iteration
we have the chance of pagefaulting.  Because we hold the extent lock for
the entire range we could mkwrite into a range in the file that we have
mmap'ed.  This would deadlock with the following stack trace

[<0>] lock_extent+0x28d/0x2f0
[<0>] btrfs_page_mkwrite+0x273/0x8a0
[<0>] do_page_mkwrite+0x50/0xb0
[<0>] do_fault+0xc1/0x7b0
[<0>] __handle_mm_fault+0x2fa/0x460
[<0>] handle_mm_fault+0xa4/0x330
[<0>] do_user_addr_fault+0x1f4/0x800
[<0>] exc_page_fault+0x7c/0x1e0
[<0>] asm_exc_page_fault+0x26/0x30
[<0>] rep_movs_alternative+0x33/0x70
[<0>] _copy_to_user+0x49/0x70
[<0>] fiemap_fill_next_extent+0xc8/0x120
[<0>] emit_fiemap_extent+0x4d/0xa0
[<0>] extent_fiemap+0x7f8/0xad0
[<0>] btrfs_fiemap+0x49/0x80
[<0>] __x64_sys_ioctl+0x3e1/0xb50
[<0>] do_syscall_64+0x94/0x1a0
[<0>] entry_SYSCALL_64_after_hwframe+0x6e/0x76

I wrote an fstest to reproduce this deadlock without my replacement lock
and verified that the deadlock exists with our existing locking.

To fix this simply don't take the extent lock for the entire duration of
the fiemap.  This is safe in general because we keep track of where we
are when we're searching the tree, so if an ordered extent updates in
the middle of our fiemap call we'll still emit the correct extents
because we know what offset we were on before.

The only place we maintain the lock is searching delalloc.  Since the
delalloc stuff can change during writeback we want to lock the extent
range so we have a consistent view of delalloc at the time we're
checking to see if we need to set the delalloc flag.

With this patch applied we no longer deadlock with my testcase.

CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-03 15:28:49 +02:00
..
9p 9p: Fix initialisation of netfs_inode for 9p 2024-02-05 20:14:32 +00:00
adfs for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
affs for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
afs afs: Revert "afs: Hide silly-rename files from userspace" 2024-03-26 18:20:03 -04:00
autofs v6.6-vfs.autofs 2023-08-28 11:39:14 -07:00
befs for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
bfs for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
btrfs btrfs: fix deadlock with fiemap and extent locking 2024-04-03 15:28:49 +02:00
cachefiles cachefiles: fix memory leak in cachefiles_add_cache() 2024-03-01 13:35:00 +01:00
ceph ceph: stop copying to iter at EOF on sync reads 2024-03-26 18:20:11 -04:00
coda v6.6-vfs.ctime 2023-08-28 09:31:32 -07:00
configfs configfs: convert to ctime accessor functions 2023-07-13 10:28:05 +02:00
cramfs v6.6-vfs.super 2023-08-28 11:04:18 -07:00
crypto
debugfs debugfs: fix automount d_fsdata usage 2024-01-20 11:51:37 +01:00
devpts v6.6-vfs.misc 2023-08-28 10:17:14 -07:00
dlm dlm: fix user space lkb refcounting 2024-04-03 15:28:32 +02:00
ecryptfs ecryptfs: Reject casefold directory inodes 2024-02-05 20:14:17 +00:00
efivarfs efivarfs: Request at most 512 bytes for variable names 2024-03-06 14:48:41 +00:00
efs for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
erofs erofs: fix lockdep false positives on initializing erofs_pseudo_mnt 2024-03-26 18:19:40 -04:00
exfat exfat: support handle zero-size directory 2023-11-28 17:19:44 +00:00
exportfs exportfs: remove kernel-doc warnings in exportfs 2023-08-29 17:45:22 -04:00
ext2 quota: Properly annotate i_dquot arrays with __rcu 2024-03-26 18:19:46 -04:00
ext4 ext4: fix corruption during on-line resize 2024-04-03 15:28:28 +02:00
f2fs f2fs: truncate page cache before clearing flags when aborting atomic write 2024-04-03 15:28:33 +02:00
fat fat: fix uninitialized field in nostale filehandles 2024-04-03 15:28:20 +02:00
freevxfs for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
fscache netfs, fscache: Prevent Oops in fscache_put_cache() 2024-01-31 16:19:01 -08:00
fuse fuse: don't unhash root 2024-04-03 15:28:25 +02:00
gfs2 gfs2: fix kernel BUG in gfs2_quota_cleanup 2024-01-25 15:35:17 -08:00
hfs for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
hfsplus for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
hostfs hostfs: convert to ctime accessor functions 2023-07-24 10:30:00 +02:00
hpfs for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
hugetlbfs mm: hugetlb pages should not be reserved by shmat() if SHM_NORESERVE 2024-02-23 09:25:16 +01:00
iomap iomap: clear the per-folio dirty bits on all writeback failures 2024-03-26 18:19:16 -04:00
isofs for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
jbd2 jbd2: fix soft lockup in journal_finish_inode_data_buffers() 2024-01-20 11:51:43 +01:00
jffs2 jffs2: convert to ctime accessor functions 2023-07-24 10:30:01 +02:00
jfs quota: Properly annotate i_dquot arrays with __rcu 2024-03-26 18:19:46 -04:00
kernfs fs/kernfs/dir: obey S_ISGID 2024-02-05 20:14:32 +00:00
lockd SUNRPC: Add enum svc_auth_status 2023-08-29 17:45:22 -04:00
minix for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
netfs netfs: Only call folio_start_fscache() one time for each folio 2023-09-18 12:03:46 -07:00
nfs NFS: Read unlock folio on nfs_page_create_from_folio() error 2024-04-03 15:28:29 +02:00
nfs_common
nfsd NFSD: Fix nfsd_clid_class use of __string_len() macro 2024-04-03 15:28:35 +02:00
nilfs2 nilfs2: prevent kernel bug at submit_bh_wbc() 2024-04-03 15:28:34 +02:00
nls nls: Hide new NLS_UCS2_UTILS 2023-08-31 12:07:34 -05:00
notify fanotify: limit reporting of event with non-decodeable file handles 2023-10-19 16:19:20 +02:00
ntfs for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
ntfs3 fs/ntfs3: fix build without CONFIG_NTFS3_LZX_XPRESS 2024-03-02 18:23:09 +01:00
ocfs2 quota: Properly annotate i_dquot arrays with __rcu 2024-03-26 18:19:46 -04:00
omfs for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
openpromfs openpromfs: convert to ctime accessor functions 2023-07-24 10:30:03 +02:00
orangefs fs: drop the timespec64 argument from update_time 2023-08-11 09:04:57 +02:00
overlayfs ovl: Always reject mounting over case-insensitive directories 2024-03-26 18:19:18 -04:00
proc fs/proc: do_task_stat: move thread_group_cputime_adjusted() outside of lock_task_sighand() 2024-02-23 09:25:17 +01:00
pstore pstore: inode: Only d_invalidate() is needed 2024-03-26 18:19:34 -04:00
qnx4 for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
qnx6 for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
quota quota: Properly annotate i_dquot arrays with __rcu 2024-03-26 18:19:46 -04:00
ramfs ramfs: convert to ctime accessor functions 2023-07-24 10:30:04 +02:00
reiserfs quota: Properly annotate i_dquot arrays with __rcu 2024-03-26 18:19:46 -04:00
romfs for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
smb cifs: open_cached_dir(): add FILE_READ_EA to desired access 2024-04-03 15:28:35 +02:00
squashfs squashfs: convert to ctime accessor functions 2023-07-24 10:30:05 +02:00
sysfs
sysv for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
tracefs eventfs: Keep all directory links at 1 2024-02-23 09:25:25 +01:00
ubifs ubifs: Set page uptodate in the correct place 2024-04-03 15:28:20 +02:00
udf \n 2023-08-30 12:10:50 -07:00
ufs for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
unicode
vboxsf v6.6-vfs.ctime 2023-08-28 09:31:32 -07:00
verity fsverity: skip PKCS#7 parser when keyring is empty 2023-08-20 10:33:43 -07:00
xfs xfs: remove conditional building of rt geometry validator functions 2024-04-03 15:28:49 +02:00
zonefs zonefs: Improve error handling 2024-02-23 09:25:13 +01:00
aio.c fs/aio: Check IOCB_AIO_RW before the struct aio_kiocb conversion 2024-04-03 15:28:44 +02:00
anon_inodes.c
attr.c v6.6-vfs.misc 2023-08-28 10:17:14 -07:00
bad_inode.c fs: drop the timespec64 argument from update_time 2023-08-11 09:04:57 +02:00
binfmt_elf_fdpic.c fs: binfmt_elf_efpic: fix personality for ELF-FDPIC 2023-09-29 17:20:45 -07:00
binfmt_elf_test.c
binfmt_elf.c Merge branch 'expand-stack' 2023-06-28 20:35:21 -07:00
binfmt_flat.c
binfmt_misc.c fs: convert to ctime accessor functions 2023-07-13 10:28:04 +02:00
binfmt_script.c
buffer.c iomap: add a workaround for racy i_size updates on block devices 2023-09-25 08:55:00 -07:00
char_dev.c
compat_binfmt_elf.c
coredump.c
d_path.c
dax.c mm: convert DAX lock/unlock page to lock/unlock folio 2024-01-10 17:16:53 +01:00
dcache.c fast_dput(): handle underflows gracefully 2024-02-05 20:14:26 +00:00
direct-io.c - Yosry Ahmed brought back some cgroup v1 stats in OOM logs. 2023-06-28 10:28:11 -07:00
drop_caches.c fs: drop_caches: draining pages before dropping caches 2023-08-18 10:12:11 -07:00
eventfd.c eventfd: prevent underflow for eventfd semaphores 2023-07-11 11:41:34 +02:00
eventpoll.c epoll: simplify ep_alloc() 2023-07-26 14:56:07 +02:00
exec.c exec: Fix error handling in begin_new_exec() 2024-01-31 16:19:06 -08:00
fcntl.c fs: Fix rw_hint validation 2024-03-26 18:19:17 -04:00
fhandle.c do_sys_name_to_handle(): use kzalloc() to fix kernel-infoleak 2024-03-26 18:19:15 -04:00
file_table.c fs: use __fput_sync in close(2) 2023-08-08 19:36:51 +02:00
file.c v6.6-vfs.misc 2023-08-28 10:17:14 -07:00
filesystems.c
fs_context.c fs: factor out vfs_parse_monolithic_sep() helper 2023-10-12 18:53:36 +03:00
fs_parser.c
fs_pin.c
fs_struct.c kill do_each_thread() 2023-08-21 13:46:25 -07:00
fs_types.c
fs-writeback.c writeback, cgroup: switch inodes with dirty timestamps to release dying cgwbs 2023-11-20 11:58:52 +01:00
fsopen.c fs: add FSCONFIG_CMD_CREATE_EXCL 2023-08-14 18:48:02 +02:00
init.c
inode.c filemap: add a per-mapping stable writes flag 2023-12-03 07:33:03 +01:00
internal.h for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
ioctl.c lsm: new security_file_ioctl_compat() hook 2024-01-31 16:18:54 -08:00
Kconfig for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
Kconfig.binfmt riscv: support the elf-fdpic binfmt loader 2023-08-23 14:17:43 -07:00
kernel_read_file.c fs: Fix kernel-doc warnings 2023-08-19 12:12:12 +02:00
libfs.c fs: new accessor methods for atime and mtime 2024-01-05 15:19:40 +01:00
locks.c NFSD 6.6 Release Notes 2023-08-31 15:32:18 -07:00
Makefile fs: add CONFIG_BUFFER_HEAD 2023-08-02 09:13:09 -06:00
mbcache.c
mnt_idmapping.c
mount.h
mpage.c
namei.c rename(): fix the locking of subdirectories 2024-01-31 16:18:57 -08:00
namespace.c fs: relax mount_setattr() permission checks 2024-02-23 09:25:15 +01:00
nsfs.c fs: convert to ctime accessor functions 2023-07-13 10:28:04 +02:00
open.c cred: get rid of CONFIG_DEBUG_CREDENTIALS 2023-12-20 17:01:51 +01:00
pipe.c pipe: wakeup wr_wait after setting max_usage 2024-01-31 16:19:09 -08:00
pnode.c
pnode.h
posix_acl.c fs: convert to ctime accessor functions 2023-07-13 10:28:04 +02:00
proc_namespace.c
read_write.c fs: Fix one kernel-doc comment 2023-08-15 08:32:45 +02:00
readdir.c vfs: get rid of old '->iterate' directory operation 2023-08-06 15:08:35 +02:00
remap_range.c
select.c fs/select: rework stack allocation hack for clang 2024-03-26 18:19:17 -04:00
seq_file.c
signalfd.c
splice.c - Some swap cleanups from Ma Wupeng ("fix WARN_ON in add_to_avail_list") 2023-08-29 14:25:26 -07:00
stack.c fs: convert to ctime accessor functions 2023-07-13 10:28:04 +02:00
stat.c fs: Pass AT_GETATTR_NOSEC flag to getattr interface function 2023-12-03 07:33:03 +01:00
statfs.c
super.c fs: export sget_dev() 2023-08-31 12:47:15 +02:00
sync.c
sysctls.c
timerfd.c
userfaultfd.c mm: userfaultfd: remove stale comment about core dump locking 2023-08-24 16:20:27 -07:00
utimes.c
xattr.c tmpfs,xattr: GFP_KERNEL_ACCOUNT for simple xattrs 2023-08-22 10:57:46 +02:00