f2fs: fix to release inode correctly

In following call stack, if unfortunately we lose all chances to truncate
inode page in remove_inode_page, eventually we will add the nid allocated
previously into free nid cache, this nid is with NID_NEW status and with
NEW_ADDR in its blkaddr pointer:

 - f2fs_create
  - f2fs_add_link
   - __f2fs_add_link
    - init_inode_metadata
     - new_inode_page
      - new_node_page
       - set_node_addr(, NEW_ADDR)
     - f2fs_init_acl   failed
     - remove_inode_page  failed
  - handle_failed_inode
   - remove_inode_page  failed
   - iput
    - f2fs_evict_inode
     - remove_inode_page  failed
     - alloc_nid_failed   cache a nid with valid blkaddr: NEW_ADDR

This may not only cause resource leak of previous inode, but also may cause
incorrect use of the previous blkaddr which is located in NO.nid node entry
when this nid is reused by others.

This patch tries to add this inode to orphan list if we fail to truncate
inode, so that we can obtain a second chance to release it in orphan
recovery flow.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

1 files changed, 46 insertions, 7 deletions

diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c
index d1b03d0..35aae65 100644
--- a/fs/f2fs/inode.c
+++ b/fs/f2fs/inode.c
@@ -317,6 +317,7 @@ void f2fs_evict_inode(struct inode *inode)
 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
 	struct f2fs_inode_info *fi = F2FS_I(inode);
 	nid_t xnid = fi->i_xattr_nid;
+	int err = 0;
 
 	/* some remained atomic pages should discarded */
 	if (f2fs_is_atomic_file(inode))
@@ -342,11 +343,13 @@ void f2fs_evict_inode(struct inode *inode)
 	i_size_write(inode, 0);
 
 	if (F2FS_HAS_BLOCKS(inode))
-		f2fs_truncate(inode, true);
+		err = f2fs_truncate(inode, true);
 
-	f2fs_lock_op(sbi);
-	remove_inode_page(inode);
-	f2fs_unlock_op(sbi);
+	if (!err) {
+		f2fs_lock_op(sbi);
+		err = remove_inode_page(inode);
+		f2fs_unlock_op(sbi);
+	}
 
 	sb_end_intwrite(inode->i_sb);
 no_delete:
@@ -362,9 +365,26 @@ no_delete:
 	if (is_inode_flag_set(fi, FI_UPDATE_WRITE))
 		add_dirty_inode(sbi, inode->i_ino, UPDATE_INO);
 	if (is_inode_flag_set(fi, FI_FREE_NID)) {
-		alloc_nid_failed(sbi, inode->i_ino);
+		if (err && err != -ENOENT)
+			alloc_nid_done(sbi, inode->i_ino);
+		else
+			alloc_nid_failed(sbi, inode->i_ino);
 		clear_inode_flag(fi, FI_FREE_NID);
 	}
+
+	if (err && err != -ENOENT) {
+		if (!exist_written_data(sbi, inode->i_ino, ORPHAN_INO)) {
+			/*
+			 * get here because we failed to release resource
+			 * of inode previously, reminder our user to run fsck
+			 * for fixing.
+			 */
+			set_sbi_flag(sbi, SBI_NEED_FSCK);
+			f2fs_msg(sbi->sb, KERN_WARNING,
+				"inode (ino:%lu) resource leak, run fsck "
+				"to fix this issue!", inode->i_ino);
+		}
+	}
 out_clear:
 #ifdef CONFIG_F2FS_FS_ENCRYPTION
 	if (fi->i_crypt_info)
@@ -377,6 +397,7 @@ out_clear:
 void handle_failed_inode(struct inode *inode)
 {
 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	int err = 0;
 
 	clear_nlink(inode);
 	make_bad_inode(inode);
@@ -384,9 +405,27 @@ void handle_failed_inode(struct inode *inode)
 
 	i_size_write(inode, 0);
 	if (F2FS_HAS_BLOCKS(inode))
-		f2fs_truncate(inode, false);
+		err = f2fs_truncate(inode, false);
+
+	if (!err)
+		err = remove_inode_page(inode);
 
-	remove_inode_page(inode);
+	/*
+	 * if we skip truncate_node in remove_inode_page bacause we failed
+	 * before, it's better to find another way to release resource of
+	 * this inode (e.g. valid block count, node block or nid). Here we
+	 * choose to add this inode to orphan list, so that we can call iput
+	 * for releasing in orphan recovery flow.
+	 *
+	 * Note: we should add inode to orphan list before f2fs_unlock_op()
+	 * so we can prevent losing this orphan when encoutering checkpoint
+	 * and following suddenly power-off.
+	 */
+	if (err && err != -ENOENT) {
+		err = acquire_orphan_inode(sbi);
+		if (!err)
+			add_orphan_inode(sbi, inode->i_ino);
+	}
 
 	set_inode_flag(F2FS_I(inode), FI_FREE_NID);
 	f2fs_unlock_op(sbi);