xattr support for btrfs

Signed-off-by: Chris Mason <chris.mason@oracle.com>

fs/btrfs/Makefile

@@ -5,7 +5,7 @@ obj-m  := btrfs.o
 btrfs-y := super.o ctree.o extent-tree.o print-tree.o root-tree.o dir-item.o \
 	   hash.o file-item.o inode-item.o inode-map.o disk-io.o \
 	   transaction.o bit-radix.o inode.o file.o tree-defrag.o \
-	   extent_map.o sysfs.o struct-funcs.o
+	   extent_map.o sysfs.o struct-funcs.o xattr.o acl.o
 
 #btrfs-y := ctree.o disk-io.o radix-tree.o extent-tree.o print-tree.o \
 #	  root-tree.o dir-item.o hash.o file-item.o inode-item.o \

fs/btrfs/acl.c

+/*
+ * Copyright (C) 2007 Red Hat.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include <linux/fs.h>
+#include <linux/string.h>
+#include <linux/xattr.h>
+#include <linux/posix_acl_xattr.h>
+#include "ctree.h"
+#include "xattr.h"
+
+static int btrfs_xattr_acl_access_get(struct inode *inode, const char *name,
+				      void *value, size_t size)
+{
+	return btrfs_xattr_get(inode, BTRFS_XATTR_INDEX_POSIX_ACL_ACCESS, name,
+			       value, size);
+}
+
+static int btrfs_xattr_acl_access_set(struct inode *inode, const char *name,
+				      const void *value, size_t size, int flags)
+{
+	return btrfs_xattr_set(inode, BTRFS_XATTR_INDEX_POSIX_ACL_ACCESS, name,
+			       value, size, flags);
+}
+
+static int btrfs_xattr_acl_default_get(struct inode *inode, const char *name,
+				       void *value, size_t size)
+{
+	return btrfs_xattr_get(inode, BTRFS_XATTR_INDEX_POSIX_ACL_DEFAULT,
+			       name, value, size);
+}
+
+static int btrfs_xattr_acl_default_set(struct inode *inode, const char *name,
+				       const void *value, size_t size, int flags)
+{
+	return btrfs_xattr_set(inode, BTRFS_XATTR_INDEX_POSIX_ACL_DEFAULT,
+			       name, value, size, flags);
+}
+
+struct xattr_handler btrfs_xattr_acl_default_handler = {
+	.prefix = POSIX_ACL_XATTR_DEFAULT,
+	.list	= btrfs_xattr_generic_list,
+	.get	= btrfs_xattr_acl_default_get,
+	.set	= btrfs_xattr_acl_default_set,
+};
+
+struct xattr_handler btrfs_xattr_acl_access_handler = {
+	.prefix = POSIX_ACL_XATTR_ACCESS,
+	.list	= btrfs_xattr_generic_list,
+	.get	= btrfs_xattr_acl_access_get,
+	.set	= btrfs_xattr_acl_access_set,
+};

fs/btrfs/ctree.h

@@ -63,7 +63,8 @@ extern struct kmem_cache *btrfs_path_cachep;
 #define BTRFS_FT_FIFO		5
 #define BTRFS_FT_SOCK		6
 #define BTRFS_FT_SYMLINK	7
-#define BTRFS_FT_MAX		8
+#define BTRFS_FT_XATTR		8
+#define BTRFS_FT_MAX		9
 
 /*
  * the key defines the order in the tree, and so it also defines (optimal)
@@ -226,7 +227,7 @@ struct btrfs_inode_item {
 
 struct btrfs_dir_item {
 	struct btrfs_disk_key location;
-	__le16 flags;
+	__le16 data_len;
 	__le16 name_len;
 	u8 type;
 } __attribute__ ((__packed__));
@@ -367,7 +368,7 @@ struct btrfs_root {
  * the FS
  */
 #define BTRFS_INODE_ITEM_KEY		1
-
+#define BTRFS_XATTR_ITEM_KEY		2
 /* reserve 2-15 close to the inode for later flexibility */
 
 /*
@@ -621,7 +622,7 @@ static inline void btrfs_set_item_key(struct extent_buffer *eb,
 }
 
 /* struct btrfs_dir_item */
-BTRFS_SETGET_FUNCS(dir_flags, struct btrfs_dir_item, flags, 16);
+BTRFS_SETGET_FUNCS(dir_data_len, struct btrfs_dir_item, data_len, 16);
 BTRFS_SETGET_FUNCS(dir_type, struct btrfs_dir_item, type, 8);
 BTRFS_SETGET_FUNCS(dir_name_len, struct btrfs_dir_item, name_len, 16);
 
@@ -962,6 +963,15 @@ int btrfs_delete_one_dir_name(struct btrfs_trans_handle *trans,
 			      struct btrfs_root *root,
 			      struct btrfs_path *path,
 			      struct btrfs_dir_item *di);
+int btrfs_insert_xattr_item(struct btrfs_trans_handle *trans,
+			    struct btrfs_root *root, const char *name,
+			    u16 name_len, const void *data, u16 data_len,
+			    u64 dir);
+struct btrfs_dir_item *btrfs_lookup_xattr(struct btrfs_trans_handle *trans,
+					  struct btrfs_root *root,
+					  struct btrfs_path *path, u64 dir,
+					  const char *name, u16 name_len,
+					  int mod);
 /* inode-map.c */
 int btrfs_find_free_objectid(struct btrfs_trans_handle *trans,
 			     struct btrfs_root *fs_root,
@@ -1039,4 +1049,8 @@ int btrfs_sysfs_add_root(struct btrfs_root *root);
 void btrfs_sysfs_del_root(struct btrfs_root *root);
 void btrfs_sysfs_del_super(struct btrfs_fs_info *root);
 
+/* xattr.c */
+ssize_t btrfs_listxattr(struct dentry *dentry, char *buffer, size_t size);
+int btrfs_delete_xattrs(struct btrfs_trans_handle *trans,
+			struct btrfs_root *root, struct inode *inode);
 #endif

fs/btrfs/dir-item.c

@@ -43,8 +43,6 @@ static struct btrfs_dir_item *insert_with_overflow(struct btrfs_trans_handle
 			return ERR_PTR(-EEXIST);
 		ret = btrfs_extend_item(trans, root, path, data_size);
 		WARN_ON(ret > 0);
-		if (ret)
-			return ERR_PTR(ret);
 	}
 	if (ret < 0)
 		return ERR_PTR(ret);
@@ -57,6 +55,57 @@ static struct btrfs_dir_item *insert_with_overflow(struct btrfs_trans_handle
 	return (struct btrfs_dir_item *)ptr;
 }
 
+int btrfs_insert_xattr_item(struct btrfs_trans_handle *trans,
+			    struct btrfs_root *root, const char *name,
+			    u16 name_len, const void *data, u16 data_len,
+			    u64 dir)
+{
+	int ret = 0;
+	struct btrfs_path *path;
+	struct btrfs_dir_item *dir_item;
+	unsigned long name_ptr, data_ptr;
+	struct btrfs_key key, location;
+	struct btrfs_disk_key disk_key;
+	struct extent_buffer *leaf;
+	u32 data_size;
+
+	key.objectid = dir;
+	btrfs_set_key_type(&key, BTRFS_XATTR_ITEM_KEY);
+	ret = btrfs_name_hash(name, name_len, &key.offset);
+	BUG_ON(ret);
+	path = btrfs_alloc_path();
+	if (!path)
+		return -ENOMEM;
+
+	data_size = sizeof(*dir_item) + name_len + data_len;
+	dir_item = insert_with_overflow(trans, root, path, &key, data_size,
+					name, name_len);
+	/*
+	 * FIXME: at some point we should handle xattr's that are larger than
+	 * what we can fit in our leaf.  We set location to NULL b/c we arent
+	 * pointing at anything else, that will change if we store the xattr
+	 * data in a separate inode.
+	 */
+	BUG_ON(IS_ERR(dir_item));
+	memset(&location, 0, sizeof(location));
+
+	leaf = path->nodes[0];
+	btrfs_cpu_key_to_disk(&disk_key, &location);
+	btrfs_set_dir_item_key(leaf, dir_item, &disk_key);
+	btrfs_set_dir_type(leaf, dir_item, BTRFS_FT_XATTR);
+	btrfs_set_dir_name_len(leaf, dir_item, name_len);
+	btrfs_set_dir_data_len(leaf, dir_item, data_len);
+	name_ptr = (unsigned long)(dir_item + 1);
+	data_ptr = (unsigned long)((char *)name_ptr + name_len);
+
+	write_extent_buffer(leaf, name, name_ptr, name_len);
+	write_extent_buffer(leaf, data, data_ptr, data_len);
+	btrfs_mark_buffer_dirty(path->nodes[0]);
+
+	btrfs_free_path(path);
+	return ret;
+}
+
 int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
 			  *root, const char *name, int name_len, u64 dir,
 			  struct btrfs_key *location, u8 type)
@@ -90,7 +139,7 @@ int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
 	btrfs_cpu_key_to_disk(&disk_key, location);
 	btrfs_set_dir_item_key(leaf, dir_item, &disk_key);
 	btrfs_set_dir_type(leaf, dir_item, type);
-	btrfs_set_dir_flags(leaf, dir_item, 0);
+	btrfs_set_dir_data_len(leaf, dir_item, 0);
 	btrfs_set_dir_name_len(leaf, dir_item, name_len);
 	name_ptr = (unsigned long)(dir_item + 1);
 
@@ -117,7 +166,7 @@ int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
 	btrfs_cpu_key_to_disk(&disk_key, location);
 	btrfs_set_dir_item_key(leaf, dir_item, &disk_key);
 	btrfs_set_dir_type(leaf, dir_item, type);
-	btrfs_set_dir_flags(leaf, dir_item, 0);
+	btrfs_set_dir_data_len(leaf, dir_item, 0);
 	btrfs_set_dir_name_len(leaf, dir_item, name_len);
 	name_ptr = (unsigned long)(dir_item + 1);
 	write_extent_buffer(leaf, name, name_ptr, name_len);
@@ -194,6 +243,43 @@ btrfs_lookup_dir_index_item(struct btrfs_trans_handle *trans,
 	return btrfs_match_dir_item_name(root, path, name, name_len);
 }
 
+struct btrfs_dir_item *btrfs_lookup_xattr(struct btrfs_trans_handle *trans,
+					  struct btrfs_root *root,
+					  struct btrfs_path *path, u64 dir,
+					  const char *name, u16 name_len,
+					  int mod)
+{
+	int ret;
+	struct btrfs_key key;
+	int ins_len = mod < 0 ? -1 : 0;
+	int cow = mod != 0;
+	struct btrfs_key found_key;
+	struct extent_buffer *leaf;
+
+	key.objectid = dir;
+	btrfs_set_key_type(&key, BTRFS_XATTR_ITEM_KEY);
+	ret = btrfs_name_hash(name, name_len, &key.offset);
+	BUG_ON(ret);
+	ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
+	if (ret < 0)
+		return ERR_PTR(ret);
+	if (ret > 0) {
+		if (path->slots[0] == 0)
+			return NULL;
+		path->slots[0]--;
+	}
+
+	leaf = path->nodes[0];
+	btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+
+	if (found_key.objectid != dir ||
+	    btrfs_key_type(&found_key) != BTRFS_XATTR_ITEM_KEY ||
+	    found_key.offset != key.offset)
+		return NULL;
+
+	return btrfs_match_dir_item_name(root, path, name, name_len);
+}
+
 struct btrfs_dir_item *btrfs_match_dir_item_name(struct btrfs_root *root,
 			      struct btrfs_path *path,
 			      const char *name, int name_len)
@@ -210,7 +296,8 @@ struct btrfs_dir_item *btrfs_match_dir_item_name(struct btrfs_root *root,
 	total_len = btrfs_item_size_nr(leaf, path->slots[0]);
 	while(cur < total_len) {
 		this_len = sizeof(*dir_item) +
-			btrfs_dir_name_len(leaf, dir_item);
+			btrfs_dir_name_len(leaf, dir_item) +
+			btrfs_dir_data_len(leaf, dir_item);
 		name_ptr = (unsigned long)(dir_item + 1);
 
 		if (btrfs_dir_name_len(leaf, dir_item) == name_len &&
@@ -236,7 +323,8 @@ int btrfs_delete_one_dir_name(struct btrfs_trans_handle *trans,
 	int ret = 0;
 
 	leaf = path->nodes[0];
-	sub_item_len = sizeof(*di) + btrfs_dir_name_len(leaf, di);
+	sub_item_len = sizeof(*di) + btrfs_dir_name_len(leaf, di) +
+		btrfs_dir_data_len(leaf, di);
 	item_len = btrfs_item_size_nr(leaf, path->slots[0]);
 	if (sub_item_len == item_len) {
 		ret = btrfs_del_item(trans, root, path);

fs/btrfs/inode.c

@@ -32,6 +32,7 @@
 #include <linux/compat.h>
 #include <linux/bit_spinlock.h>
 #include <linux/version.h>
+#include <linux/xattr.h>
 #include "ctree.h"
 #include "disk-io.h"
 #include "transaction.h"
@@ -839,6 +840,9 @@ void btrfs_delete_inode(struct inode *inode)
 
 	btrfs_set_trans_block_group(trans, inode);
 	ret = btrfs_truncate_in_trans(trans, root, inode);
+	if (ret)
+		goto no_delete_lock;
+	ret = btrfs_delete_xattrs(trans, root, inode);
 	if (ret)
 		goto no_delete_lock;
 	ret = btrfs_free_inode(trans, root, inode);
@@ -1110,7 +1114,8 @@ static int btrfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
 
 			if (over)
 				goto nopos;
-			di_len = btrfs_dir_name_len(leaf, di) + sizeof(*di);
+			di_len = btrfs_dir_name_len(leaf, di) +
+				btrfs_dir_data_len(leaf, di) +sizeof(*di);
 			di_cur += di_len;
 			di = (struct btrfs_dir_item *)((char *)di + di_len);
 		}
@@ -2519,6 +2524,10 @@ static struct inode_operations btrfs_dir_inode_operations = {
 	.symlink	= btrfs_symlink,
 	.setattr	= btrfs_setattr,
 	.mknod		= btrfs_mknod,
+	.setxattr	= generic_setxattr,
+	.getxattr	= generic_getxattr,
+	.listxattr	= btrfs_listxattr,
+	.removexattr	= generic_removexattr,
 };
 
 static struct inode_operations btrfs_dir_ro_inode_operations = {
@@ -2567,6 +2576,10 @@ static struct inode_operations btrfs_file_inode_operations = {
 	.truncate	= btrfs_truncate,
 	.getattr	= btrfs_getattr,
 	.setattr	= btrfs_setattr,
+	.setxattr	= generic_setxattr,
+	.getxattr	= generic_getxattr,
+	.listxattr      = btrfs_listxattr,
+	.removexattr	= generic_removexattr,
 };
 
 static struct inode_operations btrfs_special_inode_operations = {

fs/btrfs/print-tree.c

@@ -58,9 +58,8 @@ void btrfs_print_leaf(struct btrfs_root *root, struct extent_buffer *l)
 		case BTRFS_DIR_ITEM_KEY:
 			di = btrfs_item_ptr(l, i, struct btrfs_dir_item);
 			btrfs_dir_item_key_to_cpu(l, di, &found_key);
-			printk("\t\tdir oid %llu flags %u type %u\n",
+			printk("\t\tdir oid %llu type %u\n",
 				(unsigned long long)found_key.objectid,
-				btrfs_dir_flags(l, di),
 				btrfs_dir_type(l, di));
 			break;
 		case BTRFS_ROOT_ITEM_KEY:

fs/btrfs/super.c

@@ -40,6 +40,7 @@
 #include "btrfs_inode.h"
 #include "ioctl.h"
 #include "print-tree.h"
+#include "xattr.h"
 
 #define BTRFS_SUPER_MAGIC 0x9123683E
 
@@ -106,6 +107,7 @@ static int btrfs_fill_super(struct super_block * sb, void * data, int silent)
 	sb->s_maxbytes = MAX_LFS_FILESIZE;
 	sb->s_magic = BTRFS_SUPER_MAGIC;
 	sb->s_op = &btrfs_super_ops;
+	sb->s_xattr = btrfs_xattr_handlers;
 	sb->s_time_gran = 1;
 
 	tree_root = open_ctree(sb);

fs/btrfs/xattr.h

+/*
+ * Copyright (C) 2007 Red Hat.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#ifndef __XATTR__
+#define __XATTR__
+
+#include <linux/xattr.h>
+#include "ctree.h"
+
+/* Name indexes */
+enum {
+	BTRFS_XATTR_INDEX_USER,
+	BTRFS_XATTR_INDEX_POSIX_ACL_ACCESS,
+	BTRFS_XATTR_INDEX_POSIX_ACL_DEFAULT,
+	BTRFS_XATTR_INDEX_TRUSTED,
+	BTRFS_XATTR_INDEX_SECURITY,
+	BTRFS_XATTR_INDEX_SYSTEM,
+	BTRFS_XATTR_INDEX_END,
+};
+
+extern struct xattr_handler btrfs_xattr_user_handler;
+extern struct xattr_handler btrfs_xattr_trusted_handler;
+extern struct xattr_handler btrfs_xattr_acl_access_handler;
+extern struct xattr_handler btrfs_xattr_acl_default_handler;
+extern struct xattr_handler btrfs_xattr_security_handler;
+extern struct xattr_handler btrfs_xattr_system_handler;
+
+extern struct xattr_handler *btrfs_xattr_handlers[];
+
+ssize_t btrfs_xattr_get(struct inode *inode, int name_index, const char *name,
+			void *buffer, size_t size);
+int btrfs_xattr_set(struct inode *inode, int name_index, const char *name,
+			const void *value, size_t size, int flags);
+
+/*
+ * the only reason this is public is for acl.c.  There may be a point where
+ * acl.c doesn't need it, and if thats the case we need to remove it and make
+ * it static in xattr.c
+ */
+size_t btrfs_xattr_generic_list(struct inode *inode, char *list,
+				size_t list_size, const char *name,
+				size_t name_len);
+#endif /* __XATTR__ */