4.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Chao Yu yuchao0@huawei.com
[ Upstream commit 17cd07ae95073c298af92c1ba14ac58ce84de33b ]
As Jayashree Mohan reported:
A simple workload to reproduce this would be : 1. create foo 2. Write (8K - 16K) // foo size = 16K now 3. fsync() 4. falloc zero_range , keep_size (4202496 - 4210688) // foo size must be 16K 5. fdatasync() Crash now
On recovery, we see that the file size is 4210688 and not 16K, which violates the semantics of keep_size flag. We have a test case to reproduce this using CrashMonkey on 4.15 kernel. Try this out by simply running : ./c_harness -f /dev/sda -d /dev/cow_ram0 -t f2fs -e 102400 -P -v tests/generic_468_zero.so
The root cause is that we miss to set KEEP_SIZE bit correctly in zero_range when zeroing block cross EOF with FALLOC_FL_KEEP_SIZE, let's fix this missing case.
Signed-off-by: Chao Yu yuchao0@huawei.com Signed-off-by: Jaegeuk Kim jaegeuk@kernel.org Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/f2fs/file.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
--- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -1321,8 +1321,12 @@ static int f2fs_zero_range(struct inode }
out: - if (!(mode & FALLOC_FL_KEEP_SIZE) && i_size_read(inode) < new_size) - f2fs_i_size_write(inode, new_size); + if (new_size > i_size_read(inode)) { + if (mode & FALLOC_FL_KEEP_SIZE) + file_set_keep_isize(inode); + else + f2fs_i_size_write(inode, new_size); + } out_sem: up_write(&F2FS_I(inode)->i_mmap_sem);