[2/2] btrfs-progs: Add repair function for I_ERR_FILE_WRONG_NBYTES.

Commit Message

Qu Wenruo June 19, 2015, 3:49 a.m. UTC

Some unknown kernel bug makes inode nbytes modification out of sync with
file extent update.

But it's quite easy to fix in btrfs-progs anyway.

So just fix it by adding a new function repair_inode_nbytes by using the
found_size in inode_record.

Reported-by: Christian <[e-mail]>
Reported-by: Chris Murphy <[e-mail]>
Signed-off-by: Qu Wenruo <[e-mail]>
---
 cmds-check.c | 38 +++++++++++++++++++++++++++++++++++++-
 1 file changed, 37 insertions(+), 1 deletion(-)

Comments

David Sterba June 30, 2015, 4:42 p.m. UTC | #1

On Fri, Jun 19, 2015 at 11:49:20AM +0800, Qu Wenruo wrote:
> Some unknown kernel bug makes inode nbytes modification out of sync with
> file extent update.
> 
> But it's quite easy to fix in btrfs-progs anyway.
> 
> So just fix it by adding a new function repair_inode_nbytes by using the
> found_size in inode_record.

Please provide a test, either a crafted image or extend the
corrupt-block utility to corrupt the nbytes value on the fly.
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Patch

diff --git a/cmds-check.c b/cmds-check.c
index db121b1..80accee 100644
--- a/cmds-check.c
+++ b/cmds-check.c
@@ -1918,6 +1918,39 @@  static int repair_inode_orphan_item(struct btrfs_trans_handle *trans,
 	return ret;
 }
 
+static int repair_inode_nbytes(struct btrfs_trans_handle *trans,
+			       struct btrfs_root *root,
+			       struct btrfs_path *path,
+			       struct inode_record *rec)
+{
+	struct btrfs_inode_item *ei;
+	struct btrfs_key key;
+	int ret = 0;
+
+	key.objectid = rec->ino;
+	key.type = BTRFS_INODE_ITEM_KEY;
+	key.offset = 0;
+
+	ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
+	if (ret) {
+		if (ret > 0)
+			ret = -ENOENT;
+		goto out;
+	}
+
+	/* Since ret == 0, no need to check anything */
+	ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
+			    struct btrfs_inode_item);
+	btrfs_set_inode_nbytes(path->nodes[0], ei, rec->found_size);
+	btrfs_mark_buffer_dirty(path->nodes[0]);
+	rec->errors &= ~I_ERR_FILE_NBYTES_WRONG;
+	printf("reset nbytes for ino %llu root %llu\n",
+	       rec->ino, root->root_key.objectid);
+out:
+	btrfs_release_path(path);
+	return ret;
+}
+
 static int add_missing_dir_index(struct btrfs_root *root,
 				 struct cache_tree *inode_cache,
 				 struct inode_record *rec,
@@ -2661,7 +2694,8 @@  static int try_repair_inode(struct btrfs_root *root, struct inode_record *rec)
 			     I_ERR_LINK_COUNT_WRONG |
 			     I_ERR_NO_INODE_ITEM |
 			     I_ERR_FILE_EXTENT_ORPHAN |
-			     I_ERR_FILE_EXTENT_DISCOUNT)))
+			     I_ERR_FILE_EXTENT_DISCOUNT|
+			     I_ERR_FILE_NBYTES_WRONG)))
 		return rec->errors;
 
 	path = btrfs_alloc_path();
@@ -2693,6 +2727,8 @@  static int try_repair_inode(struct btrfs_root *root, struct inode_record *rec)
 		ret = repair_inode_orphan_item(trans, root, path, rec);
 	if (!ret && rec->errors & I_ERR_LINK_COUNT_WRONG)
 		ret = repair_inode_nlinks(trans, root, path, rec);
+	if (!ret && rec->errors & I_ERR_FILE_NBYTES_WRONG)
+		ret = repair_inode_nbytes(trans, root, path, rec);
 	btrfs_commit_transaction(trans, root);
 	btrfs_free_path(path);
 	return ret;