Fengnan Chang 0f42a02e47 f2fs: fix compressed file start atomic write may cause data corruption
[ Upstream commit 9b56adcf525522e9ffa52471260298d91fc1d395 ]

When compressed file has blocks, f2fs_ioc_start_atomic_write will succeed,
but compressed flag will be remained in inode. If write partial compreseed
cluster and commit atomic write will cause data corruption.

This is the reproduction process:
Step 1:
create a compressed file ,write 64K data , call fsync(), then the blocks
are write as compressed cluster.
Step2:
iotcl(F2FS_IOC_START_ATOMIC_WRITE)  --- this should be fail, but not.
write page 0 and page 3.
iotcl(F2FS_IOC_COMMIT_ATOMIC_WRITE)  -- page 0 and 3 write as normal file,
Step3:
drop cache.
read page 0-4   -- Since page 0 has a valid block address, read as
non-compressed cluster, page 1 and 2 will be filled with compressed data
or zero.

The root cause is, after commit 7eab7a696827 ("f2fs: compress: remove
unneeded read when rewrite whole cluster"), in step 2, f2fs_write_begin()
only set target page dirty, and in f2fs_commit_inmem_pages(), we will write
partial raw pages into compressed cluster, result in corrupting compressed
cluster layout.

Fixes: 4c8ff7095bef ("f2fs: support data compression")
Fixes: 7eab7a696827 ("f2fs: compress: remove unneeded read when rewrite whole cluster")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Fengnan Chang <changfengnan@vivo.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-08 14:23:11 +02:00
..
2022-02-08 18:34:04 +01:00
2021-12-22 09:32:45 +01:00
2021-08-19 09:02:55 +09:00
2021-09-02 12:32:12 -07:00
2021-08-26 22:28:02 +02:00
2021-11-18 19:16:48 +01:00
2021-12-29 12:28:59 +01:00
2021-06-29 10:53:48 -07:00
2021-09-03 15:33:47 -07:00
2021-08-16 10:50:32 -06:00
2021-08-19 09:02:55 +09:00
2021-12-22 09:32:48 +01:00
2021-11-25 09:48:46 +01:00
2021-08-31 11:13:35 -07:00
2021-09-09 13:25:49 -07:00
2021-11-25 09:49:08 +01:00
2021-08-31 11:06:32 -07:00
2021-06-29 10:53:48 -07:00
2021-08-18 22:08:24 +02:00
2021-12-14 10:57:15 +01:00
2021-08-10 17:57:22 +02:00