This is a note to let you know that I've just added the patch titled
f2fs: fix to avoid mmap vs set_compress_option case
to the 6.5-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
f2fs-fix-to-avoid-mmap-vs-set_compress_option-case.patch
and it can be found in the queue-6.5 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 0b42d96df10e708178b800aab20159f7501a06b6
Author: Chao Yu <chao@xxxxxxxxxx>
Date: Thu Jul 6 10:06:14 2023 +0800
f2fs: fix to avoid mmap vs set_compress_option case
[ Upstream commit b5ab3276eb69cacf44ecfb11b2bfab73096ff4e4 ]
Compression option in inode should not be changed after they have
been used, however, it may happen in below race case:
Thread A Thread B
- f2fs_ioc_set_compress_option
- check f2fs_is_mmap_file()
- check get_dirty_pages()
- check F2FS_HAS_BLOCKS()
- f2fs_file_mmap
- set_inode_flag(FI_MMAP_FILE)
- fault
- do_page_mkwrite
- f2fs_vm_page_mkwrite
- f2fs_get_block_locked
- fault_dirty_shared_page
- set_page_dirty
- update i_compress_algorithm
- update i_log_cluster_size
- update i_cluster_size
Avoid such race condition by covering f2fs_file_mmap() w/ i_sem lock,
meanwhile add mmap file check condition in f2fs_may_compress() as well.
Fixes: e1e8debec656 ("f2fs: add F2FS_IOC_SET_COMPRESS_OPTION ioctl")
Signed-off-by: Chao Yu <chao@xxxxxxxxxx>
Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index c7cb2177b2527..d372bedb0fe4e 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -4483,7 +4483,8 @@ static inline bool f2fs_low_mem_mode(struct f2fs_sb_info *sbi)
static inline bool f2fs_may_compress(struct inode *inode)
{
if (IS_SWAPFILE(inode) || f2fs_is_pinned_file(inode) ||
- f2fs_is_atomic_file(inode) || f2fs_has_inline_data(inode))
+ f2fs_is_atomic_file(inode) || f2fs_has_inline_data(inode) ||
+ f2fs_is_mmap_file(inode))
return false;
return S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode);
}
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 093039dee9920..d9073afe021fd 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -526,7 +526,11 @@ static int f2fs_file_mmap(struct file *file, struct vm_area_struct *vma)
file_accessed(file);
vma->vm_ops = &f2fs_file_vm_ops;
+
+ f2fs_down_read(&F2FS_I(inode)->i_sem);
set_inode_flag(inode, FI_MMAP_FILE);
+ f2fs_up_read(&F2FS_I(inode)->i_sem);
+
return 0;
}
@@ -1919,12 +1923,19 @@ static int f2fs_setflags_common(struct inode *inode, u32 iflags, u32 mask)
int err = f2fs_convert_inline_inode(inode);
if (err)
return err;
- if (!f2fs_may_compress(inode))
- return -EINVAL;
- if (S_ISREG(inode->i_mode) && F2FS_HAS_BLOCKS(inode))
+
+ f2fs_down_write(&F2FS_I(inode)->i_sem);
+ if (!f2fs_may_compress(inode) ||
+ (S_ISREG(inode->i_mode) &&
+ F2FS_HAS_BLOCKS(inode))) {
+ f2fs_up_write(&F2FS_I(inode)->i_sem);
return -EINVAL;
- if (set_compress_context(inode))
- return -EOPNOTSUPP;
+ }
+ err = set_compress_context(inode);
+ f2fs_up_write(&F2FS_I(inode)->i_sem);
+
+ if (err)
+ return err;
}
}
@@ -3976,6 +3987,7 @@ static int f2fs_ioc_set_compress_option(struct file *filp, unsigned long arg)
file_start_write(filp);
inode_lock(inode);
+ f2fs_down_write(&F2FS_I(inode)->i_sem);
if (f2fs_is_mmap_file(inode) || get_dirty_pages(inode)) {
ret = -EBUSY;
goto out;
@@ -3995,6 +4007,7 @@ static int f2fs_ioc_set_compress_option(struct file *filp, unsigned long arg)
f2fs_warn(sbi, "compression algorithm is successfully set, "
"but current kernel doesn't support this algorithm.");
out:
+ f2fs_up_write(&F2FS_I(inode)->i_sem);
inode_unlock(inode);
file_end_write(filp);
