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author | 2015-08-04 12:17:53 -0700 | |
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committer | 2015-08-04 15:44:42 -0700 | |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/fs/btrfs/xattr.c | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/fs/btrfs/xattr.c')
-rw-r--r-- | kernel/fs/btrfs/xattr.c | 517 |
1 files changed, 517 insertions, 0 deletions
diff --git a/kernel/fs/btrfs/xattr.c b/kernel/fs/btrfs/xattr.c new file mode 100644 index 000000000..6f518c90e --- /dev/null +++ b/kernel/fs/btrfs/xattr.c @@ -0,0 +1,517 @@ +/* + * 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 <linux/security.h> +#include <linux/posix_acl_xattr.h> +#include "ctree.h" +#include "btrfs_inode.h" +#include "transaction.h" +#include "xattr.h" +#include "disk-io.h" +#include "props.h" +#include "locking.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, btrfs_ino(inode), name, + strlen(name), 0); + if (!di) { + ret = -ENODATA; + goto out; + } else if (IS_ERR(di)) { + ret = PTR_ERR(di); + 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; + } + + /* + * The way things are packed into the leaf is like this + * |struct btrfs_dir_item|name|data| + * where name is the xattr name, so security.foo, and data is the + * content of the xattr. data_ptr points to the location in memory + * where the data starts in the in memory leaf + */ + 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; +} + +static int do_setxattr(struct btrfs_trans_handle *trans, + struct inode *inode, const char *name, + const void *value, size_t size, int flags) +{ + struct btrfs_dir_item *di = NULL; + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_path *path; + size_t name_len = strlen(name); + int ret = 0; + + if (name_len + size > BTRFS_MAX_XATTR_SIZE(root)) + return -ENOSPC; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + path->skip_release_on_error = 1; + + if (!value) { + di = btrfs_lookup_xattr(trans, root, path, btrfs_ino(inode), + name, name_len, -1); + if (!di && (flags & XATTR_REPLACE)) + ret = -ENODATA; + else if (IS_ERR(di)) + ret = PTR_ERR(di); + else if (di) + ret = btrfs_delete_one_dir_name(trans, root, path, di); + goto out; + } + + /* + * For a replace we can't just do the insert blindly. + * Do a lookup first (read-only btrfs_search_slot), and return if xattr + * doesn't exist. If it exists, fall down below to the insert/replace + * path - we can't race with a concurrent xattr delete, because the VFS + * locks the inode's i_mutex before calling setxattr or removexattr. + */ + if (flags & XATTR_REPLACE) { + ASSERT(mutex_is_locked(&inode->i_mutex)); + di = btrfs_lookup_xattr(NULL, root, path, btrfs_ino(inode), + name, name_len, 0); + if (!di) + ret = -ENODATA; + else if (IS_ERR(di)) + ret = PTR_ERR(di); + if (ret) + goto out; + btrfs_release_path(path); + di = NULL; + } + + ret = btrfs_insert_xattr_item(trans, root, path, btrfs_ino(inode), + name, name_len, value, size); + if (ret == -EOVERFLOW) { + /* + * We have an existing item in a leaf, split_leaf couldn't + * expand it. That item might have or not a dir_item that + * matches our target xattr, so lets check. + */ + ret = 0; + btrfs_assert_tree_locked(path->nodes[0]); + di = btrfs_match_dir_item_name(root, path, name, name_len); + if (!di && !(flags & XATTR_REPLACE)) { + ret = -ENOSPC; + goto out; + } + } else if (ret == -EEXIST) { + ret = 0; + di = btrfs_match_dir_item_name(root, path, name, name_len); + ASSERT(di); /* logic error */ + } else if (ret) { + goto out; + } + + if (di && (flags & XATTR_CREATE)) { + ret = -EEXIST; + goto out; + } + + if (di) { + /* + * We're doing a replace, and it must be atomic, that is, at + * any point in time we have either the old or the new xattr + * value in the tree. We don't want readers (getxattr and + * listxattrs) to miss a value, this is specially important + * for ACLs. + */ + const int slot = path->slots[0]; + struct extent_buffer *leaf = path->nodes[0]; + const u16 old_data_len = btrfs_dir_data_len(leaf, di); + const u32 item_size = btrfs_item_size_nr(leaf, slot); + const u32 data_size = sizeof(*di) + name_len + size; + struct btrfs_item *item; + unsigned long data_ptr; + char *ptr; + + if (size > old_data_len) { + if (btrfs_leaf_free_space(root, leaf) < + (size - old_data_len)) { + ret = -ENOSPC; + goto out; + } + } + + if (old_data_len + name_len + sizeof(*di) == item_size) { + /* No other xattrs packed in the same leaf item. */ + if (size > old_data_len) + btrfs_extend_item(root, path, + size - old_data_len); + else if (size < old_data_len) + btrfs_truncate_item(root, path, data_size, 1); + } else { + /* There are other xattrs packed in the same item. */ + ret = btrfs_delete_one_dir_name(trans, root, path, di); + if (ret) + goto out; + btrfs_extend_item(root, path, data_size); + } + + item = btrfs_item_nr(slot); + ptr = btrfs_item_ptr(leaf, slot, char); + ptr += btrfs_item_size(leaf, item) - data_size; + di = (struct btrfs_dir_item *)ptr; + btrfs_set_dir_data_len(leaf, di, size); + data_ptr = ((unsigned long)(di + 1)) + name_len; + write_extent_buffer(leaf, value, data_ptr, size); + btrfs_mark_buffer_dirty(leaf); + } else { + /* + * Insert, and we had space for the xattr, so path->slots[0] is + * where our xattr dir_item is and btrfs_insert_xattr_item() + * filled it. + */ + } +out: + btrfs_free_path(path); + return ret; +} + +/* + * @value: "" makes the attribute to empty, NULL removes it + */ +int __btrfs_setxattr(struct btrfs_trans_handle *trans, + struct inode *inode, const char *name, + const void *value, size_t size, int flags) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + int ret; + + if (trans) + return do_setxattr(trans, inode, name, value, size, flags); + + trans = btrfs_start_transaction(root, 2); + if (IS_ERR(trans)) + return PTR_ERR(trans); + + ret = do_setxattr(trans, inode, name, value, size, flags); + if (ret) + goto out; + + inode_inc_iversion(inode); + inode->i_ctime = CURRENT_TIME; + set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags); + ret = btrfs_update_inode(trans, root, inode); + BUG_ON(ret); +out: + btrfs_end_transaction(trans, root); + return ret; +} + +ssize_t btrfs_listxattr(struct dentry *dentry, char *buffer, size_t size) +{ + struct btrfs_key key, found_key; + struct inode *inode = d_inode(dentry); + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_path *path; + struct extent_buffer *leaf; + struct btrfs_dir_item *di; + int ret = 0, slot; + size_t total_size = 0, size_left = size; + unsigned long name_ptr; + size_t name_len; + + /* + * 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 = btrfs_ino(inode); + key.type = 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; + + while (1) { + leaf = path->nodes[0]; + slot = path->slots[0]; + + /* this is where we start walking through the path */ + if (slot >= btrfs_header_nritems(leaf)) { + /* + * if we've reached the last slot in this leaf we need + * to go to the next leaf and reset everything + */ + ret = btrfs_next_leaf(root, path); + if (ret < 0) + goto err; + else if (ret > 0) + break; + continue; + } + + 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 (found_key.type != BTRFS_XATTR_ITEM_KEY) + break; + + di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item); + if (verify_dir_item(root, leaf, di)) + goto next; + + 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) + goto next; + + 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; +next: + path->slots[0]++; + } + ret = total_size; + +err: + btrfs_free_path(path); + + return ret; +} + +/* + * List of handlers for synthetic system.* attributes. All real ondisk + * attributes are handled directly. + */ +const struct xattr_handler *btrfs_xattr_handlers[] = { +#ifdef CONFIG_BTRFS_FS_POSIX_ACL + &posix_acl_access_xattr_handler, + &posix_acl_default_xattr_handler, +#endif + NULL, +}; + +/* + * Check if the attribute is in a supported namespace. + * + * This is applied after the check for the synthetic attributes in the system + * namespace. + */ +static int btrfs_is_valid_xattr(const char *name) +{ + int len = strlen(name); + int prefixlen = 0; + + if (!strncmp(name, XATTR_SECURITY_PREFIX, + XATTR_SECURITY_PREFIX_LEN)) + prefixlen = XATTR_SECURITY_PREFIX_LEN; + else if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN)) + prefixlen = XATTR_SYSTEM_PREFIX_LEN; + else if (!strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN)) + prefixlen = XATTR_TRUSTED_PREFIX_LEN; + else if (!strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN)) + prefixlen = XATTR_USER_PREFIX_LEN; + else if (!strncmp(name, XATTR_BTRFS_PREFIX, XATTR_BTRFS_PREFIX_LEN)) + prefixlen = XATTR_BTRFS_PREFIX_LEN; + else + return -EOPNOTSUPP; + + /* + * The name cannot consist of just prefix + */ + if (len <= prefixlen) + return -EINVAL; + + return 0; +} + +ssize_t btrfs_getxattr(struct dentry *dentry, const char *name, + void *buffer, size_t size) +{ + int ret; + + /* + * 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); + + ret = btrfs_is_valid_xattr(name); + if (ret) + return ret; + return __btrfs_getxattr(d_inode(dentry), name, buffer, size); +} + +int btrfs_setxattr(struct dentry *dentry, const char *name, const void *value, + size_t size, int flags) +{ + struct btrfs_root *root = BTRFS_I(d_inode(dentry))->root; + int ret; + + /* + * The permission on security.* and system.* is not checked + * in permission(). + */ + if (btrfs_root_readonly(root)) + return -EROFS; + + /* + * 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); + + ret = btrfs_is_valid_xattr(name); + if (ret) + return ret; + + if (!strncmp(name, XATTR_BTRFS_PREFIX, XATTR_BTRFS_PREFIX_LEN)) + return btrfs_set_prop(d_inode(dentry), name, + value, size, flags); + + if (size == 0) + value = ""; /* empty EA, do not remove */ + + return __btrfs_setxattr(NULL, d_inode(dentry), name, value, size, + flags); +} + +int btrfs_removexattr(struct dentry *dentry, const char *name) +{ + struct btrfs_root *root = BTRFS_I(d_inode(dentry))->root; + int ret; + + /* + * The permission on security.* and system.* is not checked + * in permission(). + */ + if (btrfs_root_readonly(root)) + return -EROFS; + + /* + * 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); + + ret = btrfs_is_valid_xattr(name); + if (ret) + return ret; + + if (!strncmp(name, XATTR_BTRFS_PREFIX, XATTR_BTRFS_PREFIX_LEN)) + return btrfs_set_prop(d_inode(dentry), name, + NULL, 0, XATTR_REPLACE); + + return __btrfs_setxattr(NULL, d_inode(dentry), name, NULL, 0, + XATTR_REPLACE); +} + +static int btrfs_initxattrs(struct inode *inode, + const struct xattr *xattr_array, void *fs_info) +{ + const struct xattr *xattr; + struct btrfs_trans_handle *trans = fs_info; + char *name; + int err = 0; + + for (xattr = xattr_array; xattr->name != NULL; xattr++) { + name = kmalloc(XATTR_SECURITY_PREFIX_LEN + + strlen(xattr->name) + 1, GFP_NOFS); + if (!name) { + err = -ENOMEM; + break; + } + strcpy(name, XATTR_SECURITY_PREFIX); + strcpy(name + XATTR_SECURITY_PREFIX_LEN, xattr->name); + err = __btrfs_setxattr(trans, inode, name, + xattr->value, xattr->value_len, 0); + kfree(name); + if (err < 0) + break; + } + return err; +} + +int btrfs_xattr_security_init(struct btrfs_trans_handle *trans, + struct inode *inode, struct inode *dir, + const struct qstr *qstr) +{ + return security_inode_init_security(inode, dir, qstr, + &btrfs_initxattrs, trans); +} |