Root filesystem was ext4, btrfs was mounted on /testfs. Then issuing access(2) in a loop on /testfs/repos/linux/include/linux/fs.h on Sapphire Rapids (ops/s): before: 3447976 after: 3620879 (+5%) Signed-off-by: Mateusz Guzik --- fs/btrfs/inode.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 42da39c1e5b5..1a560f7298bf 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -5852,6 +5852,8 @@ struct btrfs_inode *btrfs_iget(u64 ino, struct btrfs_root *root) if (ret) return ERR_PTR(ret); + if (S_ISDIR(inode->vfs_inode.i_mode)) + inode->vfs_inode.i_opflags |= IOP_FASTPERM_MAY_EXEC; unlock_new_inode(&inode->vfs_inode); return inode; } @@ -6803,8 +6805,11 @@ static int btrfs_create_common(struct inode *dir, struct dentry *dentry, } ret = btrfs_create_new_inode(trans, &new_inode_args); - if (!ret) + if (!ret) { + if (S_ISDIR(inode->i_mode)) + inode->i_opflags |= IOP_FASTPERM_MAY_EXEC; d_instantiate_new(dentry, inode); + } btrfs_end_transaction(trans); btrfs_btree_balance_dirty(fs_info); @@ -9163,6 +9168,11 @@ int btrfs_prealloc_file_range_trans(struct inode *inode, min_size, actual_len, alloc_hint, trans); } +/* + * NOTE: in case you are adding MAY_EXEC check for directories: + * we are marking them with IOP_FASTPERM_MAY_EXEC, allowing path lookup to + * elide calls here. + */ static int btrfs_permission(struct mnt_idmap *idmap, struct inode *inode, int mask) { -- 2.48.1