[PATCH 4/5] f2fs: compress: fix to cover {reserve,release}_compress_blocks() w/ cp_rwsem lock

From: Chao Yu
Date: Mon May 06 2024 - 06:42:47 EST


It needs to cover {reserve,release}_compress_blocks() w/ cp_rwsem lock
to avoid racing with checkpoint, otherwise, filesystem metadata including
blkaddr in dnode, inode fields and .total_valid_block_count may be
corrupted after SPO case.

Fixes: ef8d563f184e ("f2fs: introduce F2FS_IOC_RELEASE_COMPRESS_BLOCKS")
Fixes: c75488fb4d82 ("f2fs: introduce F2FS_IOC_RESERVE_COMPRESS_BLOCKS")
Signed-off-by: Chao Yu <chao@xxxxxxxxxx>
---
fs/f2fs/file.c | 10 ++++++++++
1 file changed, 10 insertions(+)

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index e77e958a9f92..3f0db351e976 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -3570,9 +3570,12 @@ static int f2fs_release_compress_blocks(struct file *filp, unsigned long arg)
struct dnode_of_data dn;
pgoff_t end_offset, count;

+ f2fs_lock_op(sbi);
+
set_new_dnode(&dn, inode, NULL, NULL, 0);
ret = f2fs_get_dnode_of_data(&dn, page_idx, LOOKUP_NODE);
if (ret) {
+ f2fs_unlock_op(sbi);
if (ret == -ENOENT) {
page_idx = f2fs_get_next_page_offset(&dn,
page_idx);
@@ -3590,6 +3593,8 @@ static int f2fs_release_compress_blocks(struct file *filp, unsigned long arg)

f2fs_put_dnode(&dn);

+ f2fs_unlock_op(sbi);
+
if (ret < 0)
break;

@@ -3742,9 +3747,12 @@ static int f2fs_reserve_compress_blocks(struct file *filp, unsigned long arg)
struct dnode_of_data dn;
pgoff_t end_offset, count;

+ f2fs_lock_op(sbi);
+
set_new_dnode(&dn, inode, NULL, NULL, 0);
ret = f2fs_get_dnode_of_data(&dn, page_idx, LOOKUP_NODE);
if (ret) {
+ f2fs_unlock_op(sbi);
if (ret == -ENOENT) {
page_idx = f2fs_get_next_page_offset(&dn,
page_idx);
@@ -3762,6 +3770,8 @@ static int f2fs_reserve_compress_blocks(struct file *filp, unsigned long arg)

f2fs_put_dnode(&dn);

+ f2fs_unlock_op(sbi);
+
if (ret < 0)
break;

--
2.40.1