From: Amir Goldstein <amir73il@gmail.com> mainline inclusion from mainline-v6.7-rc1 commit 5f034d34737e8c440bbbd13e5ef283793d841140 category: feature bugzilla: https://gitee.com/src-openeuler/kernel/issues/IBHLU4 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- If ovl file is opened O_APPEND, the underlying realfile is also opened O_APPEND, so it makes sense to propagate the IOCB_APPEND flags on sync writes to realfile, just as we do with aio writes. Effectively, because sync ovl writes are protected by inode lock, this change only makes a difference if the realfile is written to (size extending writes) from underneath overlayfs. The behavior in this case is undefined, so it is ok if we change the behavior (to fail the ovl IOCB_APPEND write). Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Yifan Qiao <qiaoyifan4@huawei.com> --- fs/overlayfs/file.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c index 1f4dcf3d8540..f44017d79bce 100644 --- a/fs/overlayfs/file.c +++ b/fs/overlayfs/file.c @@ -261,7 +261,7 @@ static void ovl_file_accessed(struct file *file) } #define OVL_IOCB_MASK \ - (IOCB_NOWAIT | IOCB_HIPRI | IOCB_DSYNC | IOCB_SYNC) + (IOCB_NOWAIT | IOCB_HIPRI | IOCB_DSYNC | IOCB_SYNC | IOCB_APPEND) static rwf_t iocb_to_rw_flags(int flags) { -- 2.39.2