diff options
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/btrfs/inode.c | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index dc812ec551f6..90c23eb28829 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -2016,6 +2016,57 @@ void btrfs_orphan_cleanup(struct btrfs_root *root) } /* + * very simple check to peek ahead in the leaf looking for xattrs. If we + * don't find any xattrs, we know there can't be any acls. + * + * slot is the slot the inode is in, objectid is the objectid of the inode + */ +static noinline int acls_after_inode_item(struct extent_buffer *leaf, + int slot, u64 objectid) +{ + u32 nritems = btrfs_header_nritems(leaf); + struct btrfs_key found_key; + int scanned = 0; + + slot++; + while (slot < nritems) { + btrfs_item_key_to_cpu(leaf, &found_key, slot); + + /* we found a different objectid, there must not be acls */ + if (found_key.objectid != objectid) + return 0; + + /* we found an xattr, assume we've got an acl */ + if (found_key.type == BTRFS_XATTR_ITEM_KEY) + return 1; + + /* + * we found a key greater than an xattr key, there can't + * be any acls later on + */ + if (found_key.type > BTRFS_XATTR_ITEM_KEY) + return 0; + + slot++; + scanned++; + + /* + * it goes inode, inode backrefs, xattrs, extents, + * so if there are a ton of hard links to an inode there can + * be a lot of backrefs. Don't waste time searching too hard, + * this is just an optimization + */ + if (scanned >= 8) + break; + } + /* we hit the end of the leaf before we found an xattr or + * something larger than an xattr. We have to assume the inode + * has acls + */ + return 1; +} + +/* * read an inode from the btree into the in-memory inode */ void btrfs_read_locked_inode(struct inode *inode) @@ -2026,6 +2077,7 @@ void btrfs_read_locked_inode(struct inode *inode) struct btrfs_timespec *tspec; struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_key location; + int maybe_acls; u64 alloc_group_block; u32 rdev; int ret; @@ -2072,6 +2124,16 @@ void btrfs_read_locked_inode(struct inode *inode) alloc_group_block = btrfs_inode_block_group(leaf, inode_item); + /* + * try to precache a NULL acl entry for files that don't have + * any xattrs or acls + */ + maybe_acls = acls_after_inode_item(leaf, path->slots[0], inode->i_ino); + if (!maybe_acls) { + BTRFS_I(inode)->i_acl = NULL; + BTRFS_I(inode)->i_default_acl = NULL; + } + BTRFS_I(inode)->block_group = btrfs_find_block_group(root, 0, alloc_group_block, 0); btrfs_free_path(path); |