From: Fengnan Chang changfengnan@vivo.com
[ 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 --- fs/f2fs/data.c | 2 +- fs/f2fs/file.c | 5 ++++- 2 files changed, 5 insertions(+), 2 deletions(-)
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index e1ef925be60c..bdfa8bed10b2 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -3357,7 +3357,7 @@ static int f2fs_write_begin(struct file *file, struct address_space *mapping,
*fsdata = NULL;
- if (len == PAGE_SIZE) + if (len == PAGE_SIZE && !(f2fs_is_atomic_file(inode))) goto repeat;
ret = f2fs_prepare_compress_overwrite(inode, pagep, diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index 3c98ef6af97d..b110c3a7db6a 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -2008,7 +2008,10 @@ static int f2fs_ioc_start_atomic_write(struct file *filp)
inode_lock(inode);
- f2fs_disable_compressed_file(inode); + if (!f2fs_disable_compressed_file(inode)) { + ret = -EINVAL; + goto out; + }
if (f2fs_is_atomic_file(inode)) { if (is_inode_flag_set(inode, FI_ATOMIC_REVOKE_REQUEST))