diff options
| author | Konstantin Khlebnikov <khlebnikov@yandex-team.ru> | 2020-04-09 11:29:47 +0300 |
|---|---|---|
| committer | Miklos Szeredi <mszeredi@redhat.com> | 2020-05-13 11:11:24 +0200 |
| commit | 32b1924b210a70dcacdf65abd687c5ef86a67541 (patch) | |
| tree | 19372bfcaac553c2f8dd787e13fd0a8f23039cb2 /include/linux | |
| parent | 62a8a85be8355b01330667c2b4676fb60c184380 (diff) | |
ovl: skip overlayfs superblocks at global sync
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>
Diffstat (limited to 'include/linux')
| -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 4f6f59b4f22a..f186a966a36c 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1409,6 +1409,8 @@ 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 */ |