linux_dsm_epyc7002/fs
Sargun Dhillon 8ccf963c62 ovl: implement volatile-specific fsync error behaviour
commit 335d3fc57941e5c6164c69d439aec1cb7a800876 upstream.

Overlayfs's volatile option allows the user to bypass all forced sync calls
to the upperdir filesystem. This comes at the cost of safety. We can never
ensure that the user's data is intact, but we can make a best effort to
expose whether or not the data is likely to be in a bad state.

The best way to handle this in the time being is that if an overlayfs's
upperdir experiences an error after a volatile mount occurs, that error
will be returned on fsync, fdatasync, sync, and syncfs. This is
contradictory to the traditional behaviour of VFS which fails the call
once, and only raises an error if a subsequent fsync error has occurred,
and been raised by the filesystem.

One awkward aspect of the patch is that we have to manually set the
superblock's errseq_t after the sync_fs callback as opposed to just
returning an error from syncfs. This is because the call chain looks
something like this:

sys_syncfs ->
	sync_filesystem ->
		__sync_filesystem ->
			/* The return value is ignored here
			sb->s_op->sync_fs(sb)
			_sync_blockdev
		/* Where the VFS fetches the error to raise to userspace */
		errseq_check_and_advance

Because of this we call errseq_set every time the sync_fs callback occurs.
Due to the nature of this seen / unseen dichotomy, if the upperdir is an
inconsistent state at the initial mount time, overlayfs will refuse to
mount, as overlayfs cannot get a snapshot of the upperdir's errseq that
will increment on error until the user calls syncfs.

Signed-off-by: Sargun Dhillon <sargun@sargun.me>
Suggested-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Fixes: c86243b090 ("ovl: provide a mount option "volatile"")
Cc: stable@vger.kernel.org
Reviewed-by: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-02-10 09:29:16 +01:00
..
9p fs: 9p: add generic splice_write file operation 2020-12-01 21:40:47 +01:00
adfs Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-10-24 12:26:05 -07:00
affs Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-10-24 12:26:05 -07:00
afs rxrpc: Fix deadlock around release of dst cached on udp tunnel 2021-02-10 09:29:13 +01:00
autofs autofs: harden ioctl table 2020-10-16 11:11:22 -07:00
befs [PATCH] reduce boilerplate in fsid handling 2020-09-18 16:45:50 -04:00
bfs bfs: don't use WARNING: string when it's just info. 2021-01-06 14:56:52 +01:00
btrfs btrfs: fix possible free space tree corruption with online conversion 2021-02-03 23:28:40 +01:00
cachefiles cachefiles: Drop superfluous readpages aops NULL check 2021-01-27 11:55:22 +01:00
ceph ceph: fix inode refcount leak when ceph_fill_inode on non-I_NEW inode fails 2021-01-06 14:56:55 +01:00
cifs cifs: do not fail __smb_send_rqst if non-fatal signals are pending 2021-01-27 11:55:13 +01:00
coda
configfs fs: configfs: delete repeated words in comments 2020-10-16 11:11:19 -07:00
cramfs [PATCH] reduce boilerplate in fsid handling 2020-09-18 16:45:50 -04:00
crypto fscrypt: add fscrypt_is_nokey_name() 2020-12-26 16:02:43 +01:00
debugfs debugfs: remove return value of debugfs_create_devm_seqfile() 2020-10-30 08:37:39 +01:00
devpts
dlm networking changes for the 5.10 merge window 2020-10-15 18:42:13 -07:00
ecryptfs mm, treewide: rename kzfree() to kfree_sensitive() 2020-08-07 11:33:22 -07:00
efivarfs efivarfs: revert "fix memory leak in efivarfs_create()" 2020-11-25 16:55:02 +01:00
efs [PATCH] reduce boilerplate in fsid handling 2020-09-18 16:45:50 -04:00
erofs erofs: avoid using generic_block_bmap 2020-12-30 11:53:46 +01:00
exfat exfat: Avoid allocating upcase table using kcalloc() 2020-12-26 16:02:38 +01:00
exportfs
ext2 Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-10-24 12:26:05 -07:00
ext4 ext4: fix superblock checksum failure when setting password salt 2021-01-19 18:27:31 +01:00
f2fs f2fs: fix race of pending_pages in decompression 2021-01-06 14:56:54 +01:00
fat [PATCH] reduce boilerplate in fsid handling 2020-09-18 16:45:50 -04:00
freevxfs
fscache
fuse fuse: fix bad inode 2021-01-09 13:46:24 +01:00
gfs2 gfs2: Fix deadlock between gfs2_{create_inode,inode_lookup} and delete_work_func 2020-12-01 00:21:10 +01:00
hfs fs: Replace zero-length array with flexible-array member 2020-10-29 17:22:59 -05:00
hfsplus fs: Replace zero-length array with flexible-array member 2020-10-29 17:22:59 -05:00
hostfs
hpfs [PATCH] reduce boilerplate in fsid handling 2020-09-18 16:45:50 -04:00
hugetlbfs hugetlbfs: prevent filesystem stacking of hugetlbfs 2020-08-12 10:57:56 -07:00
iomap iomap: clean up writeback state logic on writepage error 2020-11-04 08:52:46 -08:00
isofs fs: Replace zero-length array with flexible-array member 2020-10-29 17:22:59 -05:00
jbd2 jbd2: fix kernel-doc markups 2020-11-19 22:38:29 -05:00
jffs2 jffs2: Fix NULL pointer dereference in rp_size fs option parsing 2021-01-06 14:56:49 +01:00
jfs jfs: Fix array index bounds check in dbAdjTree 2020-12-30 11:54:18 +01:00
kernfs kernfs: wire up ->splice_read and ->splice_write 2021-01-27 11:55:29 +01:00
lockd lockd: don't use interval-based rebinding over TCP 2020-12-30 11:53:30 +01:00
minix [PATCH] reduce boilerplate in fsid handling 2020-09-18 16:45:50 -04:00
nfs pNFS/NFSv4: Update the layout barrier when we schedule a layoutreturn 2021-02-03 23:28:47 +01:00
nfs_common nfs_common: need lock during iterate through the list 2020-12-30 11:53:45 +01:00
nfsd nfsd: Don't set eof on a truncated READ_PLUS 2021-01-27 11:55:05 +01:00
nilfs2 Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-10-24 12:26:05 -07:00
nls
notify fanotify: Fix sys_fanotify_mark() on native x86-32 2021-01-17 14:16:59 +01:00
ntfs Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-10-24 12:26:05 -07:00
ocfs2 ocfs2: initialize ip_next_orphan 2020-11-14 11:26:04 -08:00
omfs fs: omfs: use kmemdup() rather than kmalloc+memcpy 2020-09-22 23:39:45 -04:00
openpromfs
orangefs orangefs: remove unnecessary assignment to variable ret 2020-08-04 15:01:58 -04:00
overlayfs ovl: implement volatile-specific fsync error behaviour 2021-02-10 09:29:16 +01:00
proc proc_sysctl: fix oops caused by incorrect command parameters 2021-01-27 11:55:14 +01:00
pstore treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
qnx4 [PATCH] reduce boilerplate in fsid handling 2020-09-18 16:45:50 -04:00
qnx6 [PATCH] reduce boilerplate in fsid handling 2020-09-18 16:45:50 -04:00
quota quota: Don't overflow quota file offsets 2021-01-06 14:56:53 +01:00
ramfs ramfs: fix nommu mmap with gaps in the page cache 2020-10-16 11:11:22 -07:00
reiserfs reiserfs: add check for an invalid ih_entry_count 2021-01-06 14:56:52 +01:00
romfs Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-10-24 12:26:05 -07:00
squashfs Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-10-24 12:26:05 -07:00
sysfs sysfs: Add sysfs_emit and sysfs_emit_at to format sysfs output 2020-10-02 12:02:30 +02:00
sysv [PATCH] reduce boilerplate in fsid handling 2020-09-18 16:45:50 -04:00
tracefs
ubifs ubifs: wbuf: Don't leak kernel memory to flash 2020-12-30 11:54:17 +01:00
udf udf: fix the problem that the disc content is not displayed 2021-02-07 15:37:15 +01:00
ufs Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-10-24 12:26:05 -07:00
unicode unicode: Add utf8_casefold_hash 2020-09-10 14:03:31 -07:00
vboxsf Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2020-10-15 15:11:56 -07:00
verity fs-verity: use smp_load_acquire() for ->i_verity_info 2020-07-21 16:02:41 -07:00
xfs xfs: revert "xfs: fix rmap key and record comparison functions" 2020-11-19 15:17:50 -08:00
zonefs zonefs: select CONFIG_CRC32 2021-01-17 14:17:03 +01:00
aio.c vfs: separate __sb_start_write into blocking and non-blocking helpers 2020-11-10 16:53:07 -08:00
anon_inodes.c
attr.c
bad_inode.c
binfmt_aout.c
binfmt_elf_fdpic.c binfmt_elf, binfmt_elf_fdpic: use a VMA list snapshot 2020-10-16 11:11:21 -07:00
binfmt_elf.c fs: Replace zero-length array with flexible-array member 2020-10-29 17:22:59 -05:00
binfmt_em86.c
binfmt_flat.c binfmt_flat: revert "binfmt_flat: don't offset the data start" 2020-08-24 08:49:13 +10:00
binfmt_misc.c
binfmt_script.c
block_dev.c Revert "block: simplify set_init_blocksize" to regain lost performance 2021-02-03 23:28:45 +01:00
buffer.c mm, memcg: rework remote charging API to support nesting 2020-10-18 09:27:09 -07:00
char_dev.c
compat_binfmt_elf.c
coredump.c coredump: fix core_pattern parse error 2020-12-06 10:19:07 -08:00
d_path.c fs: fix NULL dereference due to data race in prepend_path() 2020-10-14 14:54:45 -07:00
dax.c fuse update for 5.10 2020-10-19 14:28:30 -07:00
dcache.c vfs: Use sequence counter with associated spinlock 2020-07-29 16:14:27 +02:00
dcookies.c
direct-io.c \n 2020-10-15 15:03:10 -07:00
drop_caches.c
eventfd.c
eventpoll.c epoll: check for events when removing a timed out thread from the wait queue 2020-12-30 11:54:00 +01:00
exec.c exec: Transform exec_update_mutex into a rw_semaphore 2021-01-09 13:46:24 +01:00
fcntl.c fcntl: Fix potential deadlock in send_sig{io, urg}() 2021-01-06 14:56:53 +01:00
fhandle.c
file_table.c task_work: cleanup notification modes 2020-10-17 15:05:30 -06:00
file.c kernel/io_uring: cancel io_uring before task works 2021-01-30 13:55:18 +01:00
filesystems.c
fs_context.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
fs_parser.c fs_parse: mark fs_param_bad_value() as static 2020-10-13 18:38:27 -07:00
fs_pin.c
fs_struct.c vfs: Use sequence counter with associated spinlock 2020-07-29 16:14:27 +02:00
fs_types.c
fs-writeback.c fs: fix lazytime expiration handling in __writeback_single_inode() 2021-01-27 11:54:53 +01:00
fsopen.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
init.c init: add an init_dup helper 2020-08-04 21:02:38 -04:00
inode.c fs: Handle I_DONTCACHE in iput_final() instead of generic_drop_inode() 2020-12-30 11:53:49 +01:00
internal.h fs: remove compat_sys_mount 2020-09-22 23:45:57 -04:00
io_uring.c io_uring: fix wqe->lock/completion_lock deadlock 2021-02-03 23:28:41 +01:00
io-wq.c io-wq: cancel request if it's asking for files and we don't have them 2020-11-04 10:22:56 -07:00
io-wq.h io_uring: fix io_wqe->work_list corruption 2020-12-30 11:54:03 +01:00
ioctl.c fs: remove ksys_ioctl 2020-07-31 08:16:01 +02:00
Kconfig tmpfs: support 64-bit inums per-sb 2020-08-07 11:33:24 -07:00
Kconfig.binfmt
kernel_read_file.c fs/kernel_file_read: Add "offset" arg for partial reads 2020-10-05 13:37:04 +02:00
libfs.c libfs: fix error cast of negative value in simple_attr_write() 2020-11-22 10:48:22 -08:00
locks.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
Makefile Refactored code for 5.10: 2020-10-23 11:33:41 -07:00
mbcache.c
mount.h
mpage.c
namei.c Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-10-24 12:26:05 -07:00
namespace.c umount(2): move the flag validity checks first 2021-01-19 18:27:32 +01:00
no-block.c
nsfs.c
open.c openat2: reject RESOLVE_BENEATH|RESOLVE_IN_ROOT 2020-12-30 11:54:24 +01:00
pipe.c fs/pipe: allow sendfile() to pipe again 2021-01-27 11:55:29 +01:00
pnode.c
pnode.h fs/namespace.c: WARN if mnt_count has become negative 2021-01-06 14:56:54 +01:00
posix_acl.c
proc_namespace.c proc mountinfo: make splice available again 2020-12-30 11:54:02 +01:00
read_write.c Refactored code for 5.10: 2020-10-23 11:33:41 -07:00
readdir.c fs: remove ksys_getdents64 2020-07-31 08:16:00 +02:00
remap_range.c vfs: move the remap range helpers to remap_range.c 2020-10-15 09:48:49 -07:00
select.c poll: fix performance regression due to out-of-line __put_user() 2021-01-19 18:27:27 +01:00
seq_file.c fix return values of seq_read_iter() 2020-11-15 22:12:53 -05:00
signalfd.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
splice.c io_uring-5.10-2020-10-24 2020-10-24 12:40:18 -07:00
stack.c
stat.c fs: remove KSTAT_QUERY_FLAGS 2020-09-26 22:55:05 -04:00
statfs.c Add a "nosymfollow" mount option. 2020-08-27 16:06:47 -04:00
super.c vfs: move __sb_{start,end}_write* to fs.h 2020-11-10 16:53:11 -08:00
sync.c
timerfd.c
userfaultfd.c mm: remove the now-unnecessary mmget_still_valid() hack 2020-10-16 11:11:22 -07:00
utimes.c fs: expose utimes_common 2020-07-31 08:16:01 +02:00
xattr.c fs/xattr.c: fix kernel-doc warnings for setxattr & removexattr 2020-10-13 18:38:27 -07:00