[ Upstream commit bd8309de0d60838eef6fb575b0c4c7e95841cf73 ]
fsync() needs to make sure the data & meta-data of file are persistent after the return of fsync(), even when a power-failure occurs later. In the case of fat-fs, the FAT belongs to the meta-data of file, so we need to issue a flush after the writeback of FAT instead before.
Also bail out early when any stage of fsync fails.
Link: http://lkml.kernel.org/r/20190409030158.136316-1-houtao1@huawei.com Signed-off-by: Hou Tao houtao1@huawei.com Acked-by: OGAWA Hirofumi hirofumi@mail.parknet.co.jp Cc: Al Viro viro@zeniv.linux.org.uk Cc: Jan Kara jack@suse.cz Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- fs/fat/file.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/fs/fat/file.c b/fs/fat/file.c index b3bed32946b1..0e3ed79fcc3f 100644 --- a/fs/fat/file.c +++ b/fs/fat/file.c @@ -193,12 +193,17 @@ static int fat_file_release(struct inode *inode, struct file *filp) int fat_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync) { struct inode *inode = filp->f_mapping->host; - int res, err; + int err; + + err = __generic_file_fsync(filp, start, end, datasync); + if (err) + return err;
- res = generic_file_fsync(filp, start, end, datasync); err = sync_mapping_buffers(MSDOS_SB(inode->i_sb)->fat_inode->i_mapping); + if (err) + return err;
- return res ? res : err; + return blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL); }