diff options
| author | David S. Miller <davem@davemloft.net> | 2015-06-01 22:33:25 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-06-01 22:51:30 -0700 |
| commit | dda922c831d1661c11a3ae1051b7160236f6ffb0 (patch) | |
| tree | 2fe588dbc4dc90addaabf303713fb2c6af0dc19b /fs/btrfs/backref.c | |
| parent | db3397b9aa30d334be237170e048dcd96e1e951d (diff) | |
| parent | c46a024ea5eb0165114dbbc8c82c29b7bcf66e71 (diff) | |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
drivers/net/phy/amd-xgbe-phy.c
drivers/net/wireless/iwlwifi/Kconfig
include/net/mac80211.h
iwlwifi/Kconfig and mac80211.h were both trivial overlapping
changes.
The drivers/net/phy/amd-xgbe-phy.c file got removed in 'net-next' and
the bug fix that happened on the 'net' side is already integrated
into the rest of the amd-xgbe driver.
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'fs/btrfs/backref.c')
| -rw-r--r-- | fs/btrfs/backref.c | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c index 9de772ee0031..614aaa1969bd 100644 --- a/fs/btrfs/backref.c +++ b/fs/btrfs/backref.c @@ -880,6 +880,8 @@ static int __add_keyed_refs(struct btrfs_fs_info *fs_info, * indirect refs to their parent bytenr. * When roots are found, they're added to the roots list * + * NOTE: This can return values > 0 + * * FIXME some caching might speed things up */ static int find_parent_nodes(struct btrfs_trans_handle *trans, @@ -1198,6 +1200,19 @@ int btrfs_find_all_roots(struct btrfs_trans_handle *trans, return ret; } +/** + * btrfs_check_shared - tell us whether an extent is shared + * + * @trans: optional trans handle + * + * btrfs_check_shared uses the backref walking code but will short + * circuit as soon as it finds a root or inode that doesn't match the + * one passed in. This provides a significant performance benefit for + * callers (such as fiemap) which want to know whether the extent is + * shared but do not need a ref count. + * + * Return: 0 if extent is not shared, 1 if it is shared, < 0 on error. + */ int btrfs_check_shared(struct btrfs_trans_handle *trans, struct btrfs_fs_info *fs_info, u64 root_objectid, u64 inum, u64 bytenr) @@ -1226,11 +1241,13 @@ int btrfs_check_shared(struct btrfs_trans_handle *trans, ret = find_parent_nodes(trans, fs_info, bytenr, elem.seq, tmp, roots, NULL, root_objectid, inum); if (ret == BACKREF_FOUND_SHARED) { + /* this is the only condition under which we return 1 */ ret = 1; break; } if (ret < 0 && ret != -ENOENT) break; + ret = 0; node = ulist_next(tmp, &uiter); if (!node) break; |