[PATCH 6.6.y] f2fs: release a removed xattr node in roll-forward recovery

[Sasha Levin <sashal@kernel.org>]

From: Daeho Jeong <daehojeong@google.com>

[ Upstream commit f5924de8867c09206ba631b9faed63862ec00a10 ]

When xattrs shrink enough to fit in the inline xattr area,
write_all_xattrs() truncates the xattr node and clears i_xattr_nid. If
the file is then fsynced without a checkpoint, only the inode block is
written, with i_xattr_nid of 0.

Roll-forward recovery starts from the checkpointed inode, whose
i_xattr_nid still points to the old xattr node.
f2fs_recover_inline_xattr() copies only the inline xattr area, and
f2fs_update_inode() writes the old i_xattr_nid back. So the inode keeps
the stale xattr node:

 - The node block is never released, and fsck reports "nonzero bytes in
   xattr space after end of list".
 - If the inline xattr list ends exactly at the end of the inline area,
   its terminator is read from the stale node, and the removed xattrs
   come back after recovery.

When the fsynced inode has no xattr node but the checkpointed one has,
release the old xattr node as truncate_node() does: check its block
address, invalidate the block and drop its node cache, which may still
be dirty.

Fixes: 28cdce0459cc ("f2fs: recover inline xattr data in roll-forward process")
Cc: stable@vger.kernel.org
Signed-off-by: Daeho Jeong <daehojeong@google.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
[ sashal: adapted cached-node helpers to page-based equivalents and the older f2fs_invalidate_blocks() signature ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/f2fs/node.c | 39 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index 8aa52629f788c..1d4e723d0b7eb 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -2755,6 +2755,45 @@ int f2fs_recover_inline_xattr(struct inode *inode, struct page *page)
 	f2fs_wait_on_page_writeback(ipage, NODE, true, true);
 	memcpy(dst_addr, src_addr, inline_size);
 update_inode:
+	/*
+	 * The xattr node of the checkpoint was removed before fsync, e.g. the
+	 * xattrs became small enough to fit inline. Release it as well, or
+	 * the inode keeps pointing to the stale xattrs.
+	 */
+	if (!ri->i_xattr_nid && F2FS_I(inode)->i_xattr_nid) {
+		struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+		struct node_info ni;
+		int err;
+
+		err = f2fs_get_node_info(sbi, F2FS_I(inode)->i_xattr_nid,
+								&ni, false);
+		if (err) {
+			f2fs_put_page(ipage, 1);
+			return err;
+		}
+
+		if (ni.blk_addr != NEW_ADDR &&
+		    !f2fs_is_valid_blkaddr(sbi, ni.blk_addr,
+					   DATA_GENERIC_ENHANCE)) {
+			f2fs_err_ratelimited(sbi,
+				"nat entry is corrupted, run fsck to fix it, ino:%u, nid:%u, blkaddr:%u",
+				ni.ino, ni.nid, ni.blk_addr);
+			set_sbi_flag(sbi, SBI_NEED_FSCK);
+			f2fs_handle_error(sbi, ERROR_INCONSISTENT_NAT);
+			f2fs_put_page(ipage, 1);
+			return -EFSCORRUPTED;
+		}
+
+		f2fs_invalidate_blocks(sbi, ni.blk_addr);
+		dec_valid_node_count(sbi, inode, false);
+		set_node_addr(sbi, &ni, NULL_ADDR, false);
+		/* drop the cached xattr node, which may be dirty */
+		truncate_inode_pages_range(NODE_MAPPING(sbi),
+				F2FS_BLK_TO_BYTES((loff_t)ni.nid),
+				F2FS_BLK_END_BYTES((loff_t)ni.nid));
+		f2fs_i_xnid_write(inode, 0);
+	}
+
 	f2fs_update_inode(inode, ipage);
 	f2fs_put_page(ipage, 1);
 	return 0;
-- 
2.53.0