[PATCH 3.10 72/77] Btrfs: fix scrub_print_warning to handle skinny metadata extents

Greg Kroah-Hartman
2014-06-28T17:48:55Z

From: Liu Bo <bo.li.liu@oracle.com>

commit 6eda71d0c030af0fc2f68aaa676e6d445600855b upstream.

The skinny extents are intepreted incorrectly in scrub_print_warning(),
and end up hitting the BUG() in btrfs_extent_inline_ref_size.

Reported-by: Konstantinos Skarlatos <k.skarlatos@gmail.com>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/btrfs/backref.c | 30 +++++++++++++++++++-----------
fs/btrfs/backref.h | 4 ++--
fs/btrfs/scrub.c | 5 +++--
3 files changed, 24 insertions(+), 15 deletions(-)

--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -1347,9 +1347,10 @@ int extent_from_logical(struct btrfs_fs_
* returns <0 on error
*/
static int __get_extent_inline_ref(unsigned long *ptr, struct extent_buffer *eb,
- struct btrfs_extent_item *ei, u32 item_size,
- struct btrfs_extent_inline_ref **out_eiref,
- int *out_type)
+ struct btrfs_key *key,
+ struct btrfs_extent_item *ei, u32 item_size,
+ struct btrfs_extent_inline_ref **out_eiref,
+ int *out_type)
{
unsigned long end;
u64 flags;
@@ -1359,9 +1360,16 @@ static int __get_extent_inline_ref(unsig
/* first call */
flags = btrfs_extent_flags(eb, ei);
if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
- info = (struct btrfs_tree_block_info *)(ei + 1);
- *out_eiref =
- (struct btrfs_extent_inline_ref *)(info + 1);
+ if (key->type == BTRFS_METADATA_ITEM_KEY) {
+ /* a skinny metadata extent */
+ *out_eiref =
+ (struct btrfs_extent_inline_ref *)(ei + 1);
+ } else {
+ WARN_ON(key->type != BTRFS_EXTENT_ITEM_KEY);
+ info = (struct btrfs_tree_block_info *)(ei + 1);
+ *out_eiref =
+ (struct btrfs_extent_inline_ref *)(info + 1);
+ }
} else {
*out_eiref = (struct btrfs_extent_inline_ref *)(ei + 1);
}
@@ -1371,7 +1379,7 @@ static int __get_extent_inline_ref(unsig
}

end = (unsigned long)ei + item_size;
- *out_eiref = (struct btrfs_extent_inline_ref *)*ptr;
+ *out_eiref = (struct btrfs_extent_inline_ref *)(*ptr);
*out_type = btrfs_extent_inline_ref_type(eb, *out_eiref);

*ptr += btrfs_extent_inline_ref_size(*out_type);
@@ -1390,8 +1398,8 @@ static int __get_extent_inline_ref(unsig
* <0 on error.
*/
int tree_backref_for_extent(unsigned long *ptr, struct extent_buffer *eb,
- struct btrfs_extent_item *ei, u32 item_size,
- u64 *out_root, u8 *out_level)
+ struct btrfs_key *key, struct btrfs_extent_item *ei,
+ u32 item_size, u64 *out_root, u8 *out_level)
{
int ret;
int type;
@@ -1402,8 +1410,8 @@ int tree_backref_for_extent(unsigned lon
return 1;

while (1) {
- ret = __get_extent_inline_ref(ptr, eb, ei, item_size,
- &eiref, &type);
+ ret = __get_extent_inline_ref(ptr, eb, key, ei, item_size,
+ &eiref, &type);
if (ret < 0)
return ret;

--- a/fs/btrfs/backref.h
+++ b/fs/btrfs/backref.h
@@ -42,8 +42,8 @@ int extent_from_logical(struct btrfs_fs_
u64 *flags);

int tree_backref_for_extent(unsigned long *ptr, struct extent_buffer *eb,
- struct btrfs_extent_item *ei, u32 item_size,
- u64 *out_root, u8 *out_level);
+ struct btrfs_key *key, struct btrfs_extent_item *ei,
+ u32 item_size, u64 *out_root, u8 *out_level);

int iterate_extent_inodes(struct btrfs_fs_info *fs_info,
u64 extent_item_objectid,
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -545,8 +545,9 @@ static void scrub_print_warning(const ch

if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
do {
- ret = tree_backref_for_extent(&ptr, eb, ei, item_size,
- &ref_root, &ref_level);
+ ret = tree_backref_for_extent(&ptr, eb, &found_key, ei,
+ item_size, &ref_root,
+ &ref_level);
printk_in_rcu(KERN_WARNING
"btrfs: %s at logical %llu on dev %s, "
"sector %llu: metadata %s (level %d) in tree "