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author | Lachlan McIlroy <lachlan@redback.melbourne.sgi.com> | 2009-01-14 16:29:51 +1100 |
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committer | Lachlan McIlroy <lachlan@redback.melbourne.sgi.com> | 2009-01-14 16:29:51 +1100 |
commit | cb7a97d01521797cad9f63e8478403c3e51fea49 (patch) | |
tree | 84cddf20369f82f10c1c3712e6cce20dd1b9d863 /fs/btrfs/xattr.c | |
parent | 0335cb76aa3fa913a2164bc9b669e5aef9d56fa3 (diff) | |
parent | a6525042bfdfcab128bd91fad264de10fd24a55e (diff) | |
download | linux-cb7a97d01521797cad9f63e8478403c3e51fea49.tar.bz2 |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6 into for-linus
Diffstat (limited to 'fs/btrfs/xattr.c')
-rw-r--r-- | fs/btrfs/xattr.c | 322 |
1 files changed, 322 insertions, 0 deletions
diff --git a/fs/btrfs/xattr.c b/fs/btrfs/xattr.c new file mode 100644 index 000000000000..7f332e270894 --- /dev/null +++ b/fs/btrfs/xattr.c @@ -0,0 +1,322 @@ +/* + * 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" + + +ssize_t __btrfs_getxattr(struct inode *inode, const char *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; + int ret = 0; + unsigned long data_ptr; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + /* 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_data_len(leaf, di)); + ret = btrfs_dir_data_len(leaf, di); + +out: + btrfs_free_path(path); + return ret; +} + +int __btrfs_setxattr(struct inode *inode, const char *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; + int ret = 0, mod = 0; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + 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 { + btrfs_release_path(root, path); + + if (flags & XATTR_REPLACE) { + /* we couldn't find the attr to replace */ + 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); + 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; + int ret = 0, slot, advance; + size_t total_size = 0, size_left = size; + unsigned long name_ptr; + size_t name_len; + 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(); + if (!path) + return -ENOMEM; + path->reada = 2; + + /* 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); + + name_len = btrfs_dir_name_len(leaf, di); + total_size += name_len + 1; + + /* we are just looking for how big our buffer needs to be */ + if (!size) + continue; + + if (!buffer || (name_len + 1) > size_left) { + ret = -ERANGE; + goto err; + } + + name_ptr = (unsigned long)(di + 1); + read_extent_buffer(leaf, buffer, name_ptr, name_len); + buffer[name_len] = '\0'; + + size_left -= name_len + 1; + buffer += name_len + 1; + } + ret = total_size; + +err: + btrfs_free_path(path); + + return ret; +} + +/* + * List of handlers for synthetic system.* attributes. All real ondisk + * attributes are handled directly. + */ +struct xattr_handler *btrfs_xattr_handlers[] = { +#ifdef CONFIG_FS_POSIX_ACL + &btrfs_xattr_acl_access_handler, + &btrfs_xattr_acl_default_handler, +#endif + NULL, +}; + +/* + * Check if the attribute is in a supported namespace. + * + * This applied after the check for the synthetic attributes in the system + * namespace. + */ +static bool btrfs_is_valid_xattr(const char *name) +{ + return !strncmp(name, XATTR_SECURITY_PREFIX, + XATTR_SECURITY_PREFIX_LEN) || + !strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN) || + !strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN) || + !strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN); +} + +ssize_t btrfs_getxattr(struct dentry *dentry, const char *name, + void *buffer, size_t size) +{ + /* + * If this is a request for a synthetic attribute in the system.* + * namespace use the generic infrastructure to resolve a handler + * for it via sb->s_xattr. + */ + if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN)) + return generic_getxattr(dentry, name, buffer, size); + + if (!btrfs_is_valid_xattr(name)) + return -EOPNOTSUPP; + return __btrfs_getxattr(dentry->d_inode, name, buffer, size); +} + +int btrfs_setxattr(struct dentry *dentry, const char *name, const void *value, + size_t size, int flags) +{ + /* + * If this is a request for a synthetic attribute in the system.* + * namespace use the generic infrastructure to resolve a handler + * for it via sb->s_xattr. + */ + if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN)) + return generic_setxattr(dentry, name, value, size, flags); + + if (!btrfs_is_valid_xattr(name)) + return -EOPNOTSUPP; + + if (size == 0) + value = ""; /* empty EA, do not remove */ + return __btrfs_setxattr(dentry->d_inode, name, value, size, flags); +} + +int btrfs_removexattr(struct dentry *dentry, const char *name) +{ + /* + * If this is a request for a synthetic attribute in the system.* + * namespace use the generic infrastructure to resolve a handler + * for it via sb->s_xattr. + */ + if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN)) + return generic_removexattr(dentry, name); + + if (!btrfs_is_valid_xattr(name)) + return -EOPNOTSUPP; + return __btrfs_setxattr(dentry->d_inode, name, NULL, 0, XATTR_REPLACE); +} |