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xattr support for btrfs 

Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
Josef Bacik 2007-11-16 11:45:54 -05:00 committed by Chris Mason
parent 0591fb56fb
commit 5103e947b9
9 changed files with 751 additions and 14 deletions
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2
fs/btrfs/Makefile
View File

@ -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 \

66
fs/btrfs/acl.c Normal file
View File

@ -0,0 +1,66 @@
/*
* 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,
};

22
fs/btrfs/ctree.h
View File

@ -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

100
fs/btrfs/dir-item.c
View File

@ -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 @@ second_insert:
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);

15
fs/btrfs/inode.c
View File

@ -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 = {

3
fs/btrfs/print-tree.c
View File

@ -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:

2
fs/btrfs/super.c
View File

@ -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);

497
fs/btrfs/xattr.c Normal file
View File

@ -0,0 +1,497 @@
/*
* 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/init.h>
#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/rwsem.h>
#include <linux/xattr.h>
#include "ctree.h"
#include "btrfs_inode.h"
#include "transaction.h"
#include "xattr.h"
#include "disk-io.h"
static struct xattr_handler *btrfs_xattr_handler_map[] = {
[BTRFS_XATTR_INDEX_USER] = &btrfs_xattr_user_handler,
[BTRFS_XATTR_INDEX_POSIX_ACL_ACCESS] = &btrfs_xattr_acl_access_handler,
[BTRFS_XATTR_INDEX_POSIX_ACL_DEFAULT] = &btrfs_xattr_acl_default_handler,
[BTRFS_XATTR_INDEX_TRUSTED] = &btrfs_xattr_trusted_handler,
[BTRFS_XATTR_INDEX_SECURITY] = &btrfs_xattr_security_handler,
[BTRFS_XATTR_INDEX_SYSTEM] = &btrfs_xattr_system_handler,
};
struct xattr_handler *btrfs_xattr_handlers[] = {
&btrfs_xattr_user_handler,
&btrfs_xattr_acl_access_handler,
&btrfs_xattr_acl_default_handler,
&btrfs_xattr_trusted_handler,
&btrfs_xattr_security_handler,
&btrfs_xattr_system_handler,
NULL,
};
/*
* @param name - the xattr name
* @return - the xattr_handler for the xattr, NULL if its not found
*
* use this with listxattr where we don't already know the type of xattr we
* have
*/
static struct xattr_handler *find_btrfs_xattr_handler(struct extent_buffer *l,
unsigned long name_ptr,
u16 name_len)
{
struct xattr_handler *handler = NULL;
int i = 0;
for (handler = btrfs_xattr_handlers[i]; handler != NULL; i++,
handler = btrfs_xattr_handlers[i]) {
u16 prefix_len = strlen(handler->prefix);
if (name_len < prefix_len)
continue;
if (memcmp_extent_buffer(l, handler->prefix, name_ptr,
prefix_len) == 0)
break;
}
return handler;
}
/*
* @param name_index - the index for the xattr handler
* @return the xattr_handler if we found it, NULL otherwise
*
* use this if we know the type of the xattr already
*/
static struct xattr_handler *btrfs_xattr_handler(int name_index)
{
struct xattr_handler *handler = NULL;
if (name_index >= 0 &&
name_index < ARRAY_SIZE(btrfs_xattr_handler_map))
handler = btrfs_xattr_handler_map[name_index];
return handler;
}
static inline char *get_name(const char *name, int name_index)
{
char *ret = NULL;
struct xattr_handler *handler = btrfs_xattr_handler(name_index);
int prefix_len;
if (!handler)
return ret;
prefix_len = strlen(handler->prefix);
ret = kmalloc(strlen(name) + prefix_len + 1, GFP_KERNEL);
if (!ret)
return ret;
memcpy(ret, handler->prefix, prefix_len);
memcpy(ret+prefix_len, name, strlen(name));
ret[prefix_len + strlen(name)] = '\0';
return ret;
}
size_t btrfs_xattr_generic_list(struct inode *inode, char *list,
size_t list_size, const char *name,
size_t name_len)
{
if (list && (name_len+1) <= list_size) {
memcpy(list, name, name_len);
list[name_len] = '\0';
} else
return -ERANGE;
return name_len+1;
}
ssize_t btrfs_xattr_get(struct inode *inode, int name_index,
const char *attr_name, void *buffer, size_t size)
{
struct btrfs_dir_item *di;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_path *path;
struct extent_buffer *leaf;
struct xattr_handler *handler = btrfs_xattr_handler(name_index);
int ret = 0;
unsigned long data_ptr;
char *name;
if (!handler)
return -EOPNOTSUPP;
/* just in case... */
if (*attr_name == '\0')
return -EINVAL;
name = get_name(attr_name, name_index);
if (!name)
return -ENOMEM;
path = btrfs_alloc_path();
if (!path) {
kfree(name);
return -ENOMEM;
}
mutex_lock(&root->fs_info->fs_mutex);
/* lookup the xattr by name */
di = btrfs_lookup_xattr(NULL, root, path, inode->i_ino, name,
strlen(name), 0);
if (!di || IS_ERR(di)) {
ret = -ENODATA;
goto out;
}
leaf = path->nodes[0];
/* if size is 0, that means we want the size of the attr */
if (!size) {
ret = btrfs_dir_data_len(leaf, di);
goto out;
}
/* now get the data out of our dir_item */
if (btrfs_dir_data_len(leaf, di) > size) {
ret = -ERANGE;
goto out;
}
data_ptr = (unsigned long)((char *)(di + 1) +
btrfs_dir_name_len(leaf, di));
read_extent_buffer(leaf, buffer, data_ptr,
btrfs_dir_name_len(leaf, di));
ret = btrfs_dir_data_len(leaf, di);
out:
mutex_unlock(&root->fs_info->fs_mutex);
kfree(name);
btrfs_free_path(path);
return ret;
}
int btrfs_xattr_set(struct inode *inode, int name_index,
const char *attr_name, const void *value, size_t size,
int flags)
{
struct btrfs_dir_item *di;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_trans_handle *trans;
struct btrfs_path *path;
struct xattr_handler *handler = btrfs_xattr_handler(name_index);
char *name;
int ret = 0, mod = 0;
if (!handler)
return -EOPNOTSUPP;
/* just in case... */
if (*attr_name == '\0')
return -EINVAL;
name = get_name(attr_name, name_index);
if (!name)
return -ENOMEM;
path = btrfs_alloc_path();
if (!path) {
kfree(name);
return -ENOMEM;
}
mutex_lock(&root->fs_info->fs_mutex);
trans = btrfs_start_transaction(root, 1);
btrfs_set_trans_block_group(trans, inode);
/* first lets see if we already have this xattr */
di = btrfs_lookup_xattr(trans, root, path, inode->i_ino, name,
strlen(name), -1);
if (IS_ERR(di)) {
ret = PTR_ERR(di);
goto out;
}
/* ok we already have this xattr, lets remove it */
if (di) {
/* if we want create only exit */
if (flags & XATTR_CREATE) {
ret = -EEXIST;
goto out;
}
ret = btrfs_delete_one_dir_name(trans, root, path, di);
if (ret)
goto out;
btrfs_release_path(root, path);
/* if we don't have a value then we are removing the xattr */
if (!value) {
mod = 1;
goto out;
}
} else if (flags & XATTR_REPLACE) {
/* we couldn't find the attr to replace, so error out */
ret = -ENODATA;
goto out;
}
/* ok we have to create a completely new xattr */
ret = btrfs_insert_xattr_item(trans, root, name, strlen(name),
value, size, inode->i_ino);
if (ret)
goto out;
mod = 1;
out:
if (mod) {
inode->i_ctime = CURRENT_TIME;
ret = btrfs_update_inode(trans, root, inode);
}
btrfs_end_transaction(trans, root);
mutex_unlock(&root->fs_info->fs_mutex);
kfree(name);
btrfs_free_path(path);
return ret;
}
ssize_t btrfs_listxattr(struct dentry *dentry, char *buffer, size_t size)
{
struct btrfs_key key, found_key;
struct inode *inode = dentry->d_inode;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_path *path;
struct btrfs_item *item;
struct extent_buffer *leaf;
struct btrfs_dir_item *di;
struct xattr_handler *handler;
int ret = 0, slot, advance;
size_t total_size = 0, size_left = size, written;
unsigned long name_ptr;
char *name;
u32 nritems;
/*
* ok we want all objects associated with this id.
* NOTE: we set key.offset = 0; because we want to start with the
* first xattr that we find and walk forward
*/
key.objectid = inode->i_ino;
btrfs_set_key_type(&key, BTRFS_XATTR_ITEM_KEY);
key.offset = 0;
path = btrfs_alloc_path();
path->reada = 2;
if (!path)
return -ENOMEM;
mutex_lock(&root->fs_info->fs_mutex);
/* search for our xattrs */
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto err;
ret = 0;
advance = 0;
while (1) {
leaf = path->nodes[0];
nritems = btrfs_header_nritems(leaf);
slot = path->slots[0];
/* this is where we start walking through the path */
if (advance || slot >= nritems) {
/*
* if we've reached the last slot in this leaf we need
* to go to the next leaf and reset everything
*/
if (slot >= nritems-1) {
ret = btrfs_next_leaf(root, path);
if (ret)
break;
leaf = path->nodes[0];
nritems = btrfs_header_nritems(leaf);
slot = path->slots[0];
} else {
/*
* just walking through the slots on this leaf
*/
slot++;
path->slots[0]++;
}
}
advance = 1;
item = btrfs_item_nr(leaf, slot);
btrfs_item_key_to_cpu(leaf, &found_key, slot);
/* check to make sure this item is what we want */
if (found_key.objectid != key.objectid)
break;
if (btrfs_key_type(&found_key) != BTRFS_XATTR_ITEM_KEY)
break;
di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
total_size += btrfs_dir_name_len(leaf, di)+1;
/* we are just looking for how big our buffer needs to be */
if (!size)
continue;
/* find our handler for this xattr */
name_ptr = (unsigned long)(di + 1);
handler = find_btrfs_xattr_handler(leaf, name_ptr,
btrfs_dir_name_len(leaf, di));
if (!handler) {
printk(KERN_ERR "btrfs: unsupported xattr found\n");
continue;
}
name = kmalloc(btrfs_dir_name_len(leaf, di), GFP_KERNEL);
read_extent_buffer(leaf, name, name_ptr,
btrfs_dir_name_len(leaf, di));
/* call the list function associated with this xattr */
written = handler->list(inode, buffer, size_left, name,
btrfs_dir_name_len(leaf, di));
kfree(name);
if (written < 0) {
ret = -ERANGE;
break;
}
size_left -= written;
buffer += written;
}
ret = total_size;
err:
mutex_unlock(&root->fs_info->fs_mutex);
btrfs_free_path(path);
return ret;
}
/*
* delete all the xattrs associated with the inode. fs_mutex should be
* held when we come into here
*/
int btrfs_delete_xattrs(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct inode *inode)
{
struct btrfs_path *path;
struct btrfs_key key, found_key;
struct btrfs_item *item;
struct extent_buffer *leaf;
int ret;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
key.objectid = inode->i_ino;
btrfs_set_key_type(&key, BTRFS_XATTR_ITEM_KEY);
key.offset = (u64)-1;
while(1) {
/* look for our next xattr */
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret < 0)
goto out;
BUG_ON(ret == 0);
if (path->slots[0] == 0)
break;
path->slots[0]--;
leaf = path->nodes[0];
item = btrfs_item_nr(leaf, path->slots[0]);
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
if (found_key.objectid != key.objectid)
break;
if (btrfs_key_type(&found_key) != BTRFS_XATTR_ITEM_KEY)
break;
ret = btrfs_del_item(trans, root, path);
BUG_ON(ret);
btrfs_release_path(root, path);
}
ret = 0;
out:
btrfs_free_path(path);
return ret;
}
/*
* Handler functions
*/
#define BTRFS_XATTR_SETGET_FUNCS(name, index) \
static int btrfs_xattr_##name##_get(struct inode *inode, \
const char *name, void *value, \
size_t size) \
{ \
return btrfs_xattr_get(inode, index, name, value, size); \
} \
static int btrfs_xattr_##name##_set(struct inode *inode, \
const char *name, const void *value,\
size_t size, int flags) \
{ \
return btrfs_xattr_set(inode, index, name, value, size, flags); \
} \
BTRFS_XATTR_SETGET_FUNCS(security, BTRFS_XATTR_INDEX_SECURITY);
BTRFS_XATTR_SETGET_FUNCS(system, BTRFS_XATTR_INDEX_SYSTEM);
BTRFS_XATTR_SETGET_FUNCS(user, BTRFS_XATTR_INDEX_USER);
BTRFS_XATTR_SETGET_FUNCS(trusted, BTRFS_XATTR_INDEX_TRUSTED);
struct xattr_handler btrfs_xattr_security_handler = {
.prefix = XATTR_SECURITY_PREFIX,
.list = btrfs_xattr_generic_list,
.get = btrfs_xattr_security_get,
.set = btrfs_xattr_security_set,
};
struct xattr_handler btrfs_xattr_system_handler = {
.prefix = XATTR_SYSTEM_PREFIX,
.list = btrfs_xattr_generic_list,
.get = btrfs_xattr_system_get,
.set = btrfs_xattr_system_set,
};
struct xattr_handler btrfs_xattr_user_handler = {
.prefix = XATTR_USER_PREFIX,
.list = btrfs_xattr_generic_list,
.get = btrfs_xattr_user_get,
.set = btrfs_xattr_user_set,
};
struct xattr_handler btrfs_xattr_trusted_handler = {
.prefix = XATTR_USER_PREFIX,
.list = btrfs_xattr_generic_list,
.get = btrfs_xattr_trusted_get,
.set = btrfs_xattr_trusted_set,
};

58
fs/btrfs/xattr.h Normal file
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@ -0,0 +1,58 @@
/*
* 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__ */