From: Chao Yu <[email protected]> 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 <[email protected]> --- fs/f2fs/file.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index f64bcd0a7f73..6a202e5a6386 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -1348,8 +1348,12 @@ static int f2fs_zero_range(struct inode *inode, loff_t offset, loff_t len, } 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); -- 2.14.1.145.gb3622a4ee
