int verify_dir_item(struct btrfs_root *root,
struct extent_buffer *leaf,
struct btrfs_dir_item *dir_item)
{
u16 namelen = BTRFS_NAME_LEN;
u8 type = btrfs_dir_type(leaf, dir_item);
if (type >= BTRFS_FT_MAX) {
printk(KERN_CRIT "btrfs: invalid dir item type: %d\n",
(int)type);
return 1;
}
if (type == BTRFS_FT_XATTR)
namelen = XATTR_NAME_MAX;
if (btrfs_dir_name_len(leaf, dir_item) > namelen) {
printk(KERN_CRIT "btrfs: invalid dir item name len: %u\n",
(unsigned)btrfs_dir_data_len(leaf, dir_item));
return 1;
}
/* BTRFS_MAX_XATTR_SIZE is the same for all dir items */
if ((btrfs_dir_data_len(leaf, dir_item) +
btrfs_dir_name_len(leaf, dir_item)) > BTRFS_MAX_XATTR_SIZE(root)) {
printk(KERN_CRIT "btrfs: invalid dir item name + data len: %u + %u\n",
(unsigned)btrfs_dir_name_len(leaf, dir_item),
(unsigned)btrfs_dir_data_len(leaf, dir_item));
return 1;
}
return 0;
}
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;
}
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;
/* */
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) {
ret = btrfs_dir_data_len(leaf, di);
goto out;
}
/* */
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;
}
static int print_dir_item(struct extent_buffer *eb, struct btrfs_item *item,
struct btrfs_dir_item *di)
{
u32 total;
u32 cur = 0;
u32 len;
u32 name_len;
u32 data_len;
char namebuf[BTRFS_NAME_LEN];
struct btrfs_disk_key location;
total = btrfs_item_size(eb, item);
while(cur < total) {
btrfs_dir_item_key(eb, di, &location);
printf("\t\tlocation ");
btrfs_print_key(&location);
printf(" type %u\n", btrfs_dir_type(eb, di));
name_len = btrfs_dir_name_len(eb, di);
data_len = btrfs_dir_data_len(eb, di);
len = (name_len <= sizeof(namebuf))? name_len: sizeof(namebuf);
read_extent_buffer(eb, namebuf, (unsigned long)(di + 1), len);
printf("\t\tnamelen %u datalen %u name: %.*s\n",
name_len, data_len, len, namebuf);
if (data_len) {
len = (data_len <= sizeof(namebuf))? data_len: sizeof(namebuf);
read_extent_buffer(eb, namebuf,
(unsigned long)(di + 1) + name_len, len);
printf("\t\tdata %.*s\n", len, namebuf);
}
len = sizeof(*di) + name_len + data_len;
di = (struct btrfs_dir_item *)((char *)di + len);
cur += len;
}
return 0;
}
/*
* given a pointer into a directory item, delete it. This
* handles items that have more than one entry in them.
*/
int btrfs_delete_one_dir_name(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct btrfs_dir_item *di)
{
struct extent_buffer *leaf;
u32 sub_item_len;
u32 item_len;
int ret = 0;
leaf = path->nodes[0];
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);
} else {
/* MARKER */
unsigned long ptr = (unsigned long)di;
unsigned long start;
start = btrfs_item_ptr_offset(leaf, path->slots[0]);
memmove_extent_buffer(leaf, ptr, ptr + sub_item_len,
item_len - (ptr + sub_item_len - start));
btrfs_truncate_item(trans, root, path,
item_len - sub_item_len, 1);
}
return ret;
}
/*
* helper function to look at the directory item pointed to by 'path'
* this walks through all the entries in a dir item and finds one
* for a specific name.
*/
struct btrfs_dir_item *btrfs_match_dir_item_name(struct btrfs_root *root,
struct btrfs_path *path,
const char *name, int name_len)
{
struct btrfs_dir_item *dir_item;
unsigned long name_ptr;
u32 total_len;
u32 cur = 0;
u32 this_len;
struct extent_buffer *leaf;
leaf = path->nodes[0];
dir_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dir_item);
if (verify_dir_item(root, leaf, dir_item))
return NULL;
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_data_len(leaf, dir_item);
name_ptr = (unsigned long)(dir_item + 1);
if (btrfs_dir_name_len(leaf, dir_item) == name_len &&
memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0)
return dir_item;
cur += this_len;
dir_item = (struct btrfs_dir_item *)((char *)dir_item +
this_len);
}
return NULL;
}
static void print_dir_item(struct extent_buffer *eb, u32 size,
struct btrfs_dir_item *di)
{
u32 cur = 0;
u32 len;
u32 name_len;
u32 data_len;
char namebuf[BTRFS_NAME_LEN];
struct btrfs_disk_key location;
while (cur < size) {
btrfs_dir_item_key(eb, di, &location);
printf("\t\tlocation ");
btrfs_print_key(&location);
printf(" type ");
print_dir_item_type(eb, di);
printf("\n");
name_len = btrfs_dir_name_len(eb, di);
data_len = btrfs_dir_data_len(eb, di);
len = (name_len <= sizeof(namebuf))? name_len: sizeof(namebuf);
read_extent_buffer(eb, namebuf, (unsigned long)(di + 1), len);
printf("\t\ttransid %llu data_len %u name_len %u\n",
btrfs_dir_transid(eb, di),
data_len, name_len);
printf("\t\tname: %.*s\n", len, namebuf);
if (data_len) {
len = (data_len <= sizeof(namebuf))? data_len: sizeof(namebuf);
read_extent_buffer(eb, namebuf,
(unsigned long)(di + 1) + name_len, len);
printf("\t\tdata %.*s\n", len, namebuf);
}
len = sizeof(*di) + name_len + data_len;
di = (struct btrfs_dir_item *)((char *)di + len);
cur += len;
}
}
static int set_file_xattrs(struct btrfs_root *root, u64 inode,
int fd, const char *file_name)
{
struct btrfs_key key;
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_dir_item *di;
u32 name_len = 0;
u32 data_len = 0;
u32 len = 0;
u32 cur, total_len;
char *name = NULL;
char *data = NULL;
int ret = 0;
key.objectid = inode;
key.type = BTRFS_XATTR_ITEM_KEY;
key.offset = 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto out;
leaf = path->nodes[0];
while (1) {
if (path->slots[0] >= btrfs_header_nritems(leaf)) {
do {
ret = next_leaf(root, path);
if (ret < 0) {
fprintf(stderr,
"Error searching for extended attributes: %d\n",
ret);
goto out;
} else if (ret) {
/* No more leaves to search */
ret = 0;
goto out;
}
leaf = path->nodes[0];
} while (!leaf);
continue;
}
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
if (key.type != BTRFS_XATTR_ITEM_KEY || key.objectid != inode)
break;
cur = 0;
total_len = btrfs_item_size_nr(leaf, path->slots[0]);
di = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_dir_item);
while (cur < total_len) {
len = btrfs_dir_name_len(leaf, di);
if (len > name_len) {
free(name);
name = (char *) malloc(len + 1);
if (!name) {
ret = -ENOMEM;
goto out;
}
}
read_extent_buffer(leaf, name,
(unsigned long)(di + 1), len);
name[len] = '\0';
name_len = len;
len = btrfs_dir_data_len(leaf, di);
if (len > data_len) {
free(data);
data = (char *) malloc(len);
if (!data) {
ret = -ENOMEM;
goto out;
}
}
read_extent_buffer(leaf, data,
(unsigned long)(di + 1) + name_len,
len);
data_len = len;
if (fsetxattr(fd, name, data, data_len, 0)) {
int err = errno;
fprintf(stderr,
"Error setting extended attribute %s on file %s: %s\n",
name, file_name, strerror(err));
}
len = sizeof(*di) + name_len + data_len;
cur += len;
di = (struct btrfs_dir_item *)((char *)di + len);
}
path->slots[0]++;
}
ret = 0;
out:
btrfs_free_path(path);
free(name);
free(data);
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(inode_is_locked(inode));
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.
*/
}
ssize_t btrfs_listxattr(struct dentry *dentry, char *buffer, size_t size)
{
struct btrfs_key key;
struct inode *inode = d_inode(dentry);
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_path *path;
int ret = 0;
size_t total_size = 0, size_left = size;
/*
* 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 = READA_FORWARD;
/* search for our xattrs */
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto err;
while (1) {
struct extent_buffer *leaf;
int slot;
struct btrfs_dir_item *di;
struct btrfs_key found_key;
u32 item_size;
u32 cur;
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;
if (found_key.type < BTRFS_XATTR_ITEM_KEY)
goto next_item;
di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
item_size = btrfs_item_size_nr(leaf, slot);
cur = 0;
while (cur < item_size) {
u16 name_len = btrfs_dir_name_len(leaf, di);
u16 data_len = btrfs_dir_data_len(leaf, di);
u32 this_len = sizeof(*di) + name_len + data_len;
unsigned long name_ptr = (unsigned long)(di + 1);
if (verify_dir_item(root, leaf, di)) {
ret = -EIO;
goto err;
}
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;
}
read_extent_buffer(leaf, buffer, name_ptr, name_len);
buffer[name_len] = '\0';
size_left -= name_len + 1;
buffer += name_len + 1;
next:
cur += this_len;
di = (struct btrfs_dir_item *)((char *)di + this_len);
}
next_item:
path->slots[0]++;
}
ret = total_size;
err:
btrfs_free_path(path);
return ret;
}
