[PATCH 6.1 362/451] f2fs: compress: fix to cover f2fs_disable_compressed_file() w/ i_sem

Sasha Levin
2024-03-24T23:17:59Z

From: Chao Yu <chao@kernel.org>

[ Upstream commit 2f9420d3a94aeebd92db88f00f4f2f1a3bd3f6cf ]

- f2fs_disable_compressed_file
- check inode_has_data
- f2fs_file_mmap
- mkwrite
- f2fs_get_block_locked
: update metadata in compressed
inode's disk layout
- fi->i_flags &= ~F2FS_COMPR_FL
- clear_inode_flag(inode, FI_COMPRESSED_FILE);

we should use i_sem lock to prevent above race case.

Fixes: 4c8ff7095bef ("f2fs: support data compression")
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/f2fs/f2fs.h | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 2afb91471b535..a81091a5e282d 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -4367,15 +4367,24 @@ static inline bool f2fs_disable_compressed_file(struct inode *inode)
{
struct f2fs_inode_info *fi = F2FS_I(inode);

- if (!f2fs_compressed_file(inode))
+ f2fs_down_write(&F2FS_I(inode)->i_sem);
+
+ if (!f2fs_compressed_file(inode)) {
+ f2fs_up_write(&F2FS_I(inode)->i_sem);
return true;
- if (S_ISREG(inode->i_mode) && F2FS_HAS_BLOCKS(inode))
+ }
+ if (f2fs_is_mmap_file(inode) ||
+ (S_ISREG(inode->i_mode) && F2FS_HAS_BLOCKS(inode))) {
+ f2fs_up_write(&F2FS_I(inode)->i_sem);
return false;
+ }

fi->i_flags &= ~F2FS_COMPR_FL;
stat_dec_compr_inode(inode);
clear_inode_flag(inode, FI_COMPRESSED_FILE);
f2fs_mark_inode_dirty_sync(inode, true);
+
+ f2fs_up_write(&F2FS_I(inode)->i_sem);
return true;
}

--
2.43.0