f2fs: compress: fix to cover {reserve,release}_compress_blocks() w/ cp_rwsem lock

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@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index f03ae3d952cc03309cdbfbc867588936f0368d92..2a9de84d2a717b73e390175c372df65472e46dc0 100644 (file)
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -3593,9 +3593,12 @@ 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);
@@ -3613,6 +3616,8 @@ static int f2fs_release_compress_blocks(struct file *filp, unsigned long arg)
 
                f2fs_put_dnode(&dn);
 
+               f2fs_unlock_op(sbi);
+
                if (ret < 0)
                        break;
 
@@ -3765,9 +3770,12 @@ 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);
@@ -3785,6 +3793,8 @@ static int f2fs_reserve_compress_blocks(struct file *filp, unsigned long arg)
 
                f2fs_put_dnode(&dn);
 
+               f2fs_unlock_op(sbi);
+
                if (ret < 0)
                        break;