diff options
| author | Konstantin Khlebnikov <khlebnikov@yandex-team.ru> | 2020-04-09 11:29:47 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-12-08 08:44:27 +0100 |
| commit | 8c85e455f7c9682d2728e64aaaf36b8c490dfce3 (patch) | |
| tree | 8c4659ef0703ad2c2de52c4b966c5c40c60aeb99 /include | |
| parent | 157c8056abb5982ebcc2a06f14a8725dec7cc956 (diff) | |
ovl: skip overlayfs superblocks at global sync
[ Upstream commit 32b1924b210a70dcacdf65abd687c5ef86a67541 ]
Stacked filesystems like overlayfs has no own writeback, but they have to
forward syncfs() requests to backend for keeping data integrity.
During global sync() each overlayfs instance calls method ->sync_fs() for
backend although it itself is in global list of superblocks too. As a
result one syscall sync() could write one superblock several times and send
multiple disk barriers.
This patch adds flag SB_I_SKIP_SYNC into sb->sb_iflags to avoid that.
Reported-by: Dmitry Monakhov <dmtrmonakhov@yandex-team.ru>
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Stable-dep-of: b836c4d29f27 ("ima: detect changes to the backing overlay file")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/fs.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/fs.h b/include/linux/fs.h index 4b1553f570f2..fbbd7ef7f653 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1404,6 +1404,8 @@ extern int send_sigurg(struct fown_struct *fown); #define SB_I_IMA_UNVERIFIABLE_SIGNATURE 0x00000020 #define SB_I_UNTRUSTED_MOUNTER 0x00000040 +#define SB_I_SKIP_SYNC 0x00000100 /* Skip superblock at global sync */ + /* Possible states of 'frozen' field */ enum { SB_UNFROZEN = 0, /* FS is unfrozen */ |