Btrfs: add search and inode lookup ioctls
The search ioctl is a generic tool for doing btree searches from userland applications. The first user of the search ioctl is a subvolume listing feature, but we'll also use it to find new files in a subvolume. The search ioctl allows you to specify min and max keys to search for, along with min and max transid. It returns the items along with a header that includes the item key. Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
Chris Mason
parent
98d377a089
commit
ac8e9819d7
249
fs/btrfs/ioctl.c
249
fs/btrfs/ioctl.c
|
|
@ -744,16 +744,206 @@ out:
|
|||
return ret;
|
||||
}
|
||||
|
||||
static noinline int key_in_sk(struct btrfs_key *key,
|
||||
struct btrfs_ioctl_search_key *sk)
|
||||
{
|
||||
if (key->objectid < sk->min_objectid)
|
||||
return 0;
|
||||
if (key->offset < sk->min_offset)
|
||||
return 0;
|
||||
if (key->type < sk->min_type)
|
||||
return 0;
|
||||
if (key->objectid > sk->max_objectid)
|
||||
return 0;
|
||||
if (key->type > sk->max_type)
|
||||
return 0;
|
||||
if (key->offset > sk->max_offset)
|
||||
return 0;
|
||||
return 1;
|
||||
}
|
||||
|
||||
static noinline int copy_to_sk(struct btrfs_root *root,
|
||||
struct btrfs_path *path,
|
||||
struct btrfs_key *key,
|
||||
struct btrfs_ioctl_search_key *sk,
|
||||
char *buf,
|
||||
unsigned long *sk_offset,
|
||||
int *num_found)
|
||||
{
|
||||
u64 found_transid;
|
||||
struct extent_buffer *leaf;
|
||||
struct btrfs_ioctl_search_header sh;
|
||||
unsigned long item_off;
|
||||
unsigned long item_len;
|
||||
int nritems;
|
||||
int i;
|
||||
int slot;
|
||||
int found = 0;
|
||||
int ret = 0;
|
||||
|
||||
leaf = path->nodes[0];
|
||||
slot = path->slots[0];
|
||||
nritems = btrfs_header_nritems(leaf);
|
||||
|
||||
if (btrfs_header_generation(leaf) > sk->max_transid) {
|
||||
i = nritems;
|
||||
goto advance_key;
|
||||
}
|
||||
found_transid = btrfs_header_generation(leaf);
|
||||
|
||||
for (i = slot; i < nritems; i++) {
|
||||
item_off = btrfs_item_ptr_offset(leaf, i);
|
||||
item_len = btrfs_item_size_nr(leaf, i);
|
||||
|
||||
if (item_len > BTRFS_SEARCH_ARGS_BUFSIZE)
|
||||
item_len = 0;
|
||||
|
||||
if (sizeof(sh) + item_len + *sk_offset >
|
||||
BTRFS_SEARCH_ARGS_BUFSIZE) {
|
||||
ret = 1;
|
||||
goto overflow;
|
||||
}
|
||||
|
||||
btrfs_item_key_to_cpu(leaf, key, i);
|
||||
if (!key_in_sk(key, sk))
|
||||
continue;
|
||||
|
||||
sh.objectid = key->objectid;
|
||||
sh.offset = key->offset;
|
||||
sh.type = key->type;
|
||||
sh.len = item_len;
|
||||
sh.transid = found_transid;
|
||||
|
||||
/* copy search result header */
|
||||
memcpy(buf + *sk_offset, &sh, sizeof(sh));
|
||||
*sk_offset += sizeof(sh);
|
||||
|
||||
if (item_len) {
|
||||
char *p = buf + *sk_offset;
|
||||
/* copy the item */
|
||||
read_extent_buffer(leaf, p,
|
||||
item_off, item_len);
|
||||
*sk_offset += item_len;
|
||||
found++;
|
||||
}
|
||||
|
||||
if (*num_found >= sk->nr_items)
|
||||
break;
|
||||
}
|
||||
advance_key:
|
||||
if (key->offset < (u64)-1)
|
||||
key->offset++;
|
||||
else if (key->type < (u64)-1)
|
||||
key->type++;
|
||||
else if (key->objectid < (u64)-1)
|
||||
key->objectid++;
|
||||
ret = 0;
|
||||
overflow:
|
||||
*num_found += found;
|
||||
return ret;
|
||||
}
|
||||
|
||||
static noinline int search_ioctl(struct inode *inode,
|
||||
struct btrfs_ioctl_search_args *args)
|
||||
{
|
||||
struct btrfs_root *root;
|
||||
struct btrfs_key key;
|
||||
struct btrfs_key max_key;
|
||||
struct btrfs_path *path;
|
||||
struct btrfs_ioctl_search_key *sk = &args->key;
|
||||
struct btrfs_fs_info *info = BTRFS_I(inode)->root->fs_info;
|
||||
int ret;
|
||||
int num_found = 0;
|
||||
unsigned long sk_offset = 0;
|
||||
|
||||
path = btrfs_alloc_path();
|
||||
if (!path)
|
||||
return -ENOMEM;
|
||||
|
||||
if (sk->tree_id == 0) {
|
||||
/* search the root of the inode that was passed */
|
||||
root = BTRFS_I(inode)->root;
|
||||
} else {
|
||||
key.objectid = sk->tree_id;
|
||||
key.type = BTRFS_ROOT_ITEM_KEY;
|
||||
key.offset = (u64)-1;
|
||||
root = btrfs_read_fs_root_no_name(info, &key);
|
||||
if (IS_ERR(root)) {
|
||||
printk(KERN_ERR "could not find root %llu\n",
|
||||
sk->tree_id);
|
||||
btrfs_free_path(path);
|
||||
return -ENOENT;
|
||||
}
|
||||
}
|
||||
|
||||
key.objectid = sk->min_objectid;
|
||||
key.type = sk->min_type;
|
||||
key.offset = sk->min_offset;
|
||||
|
||||
max_key.objectid = sk->max_objectid;
|
||||
max_key.type = sk->max_type;
|
||||
max_key.offset = sk->max_offset;
|
||||
|
||||
path->keep_locks = 1;
|
||||
|
||||
while(1) {
|
||||
ret = btrfs_search_forward(root, &key, &max_key, path, 0,
|
||||
sk->min_transid);
|
||||
if (ret != 0) {
|
||||
if (ret > 0)
|
||||
ret = 0;
|
||||
goto err;
|
||||
}
|
||||
ret = copy_to_sk(root, path, &key, sk, args->buf,
|
||||
&sk_offset, &num_found);
|
||||
btrfs_release_path(root, path);
|
||||
if (ret || num_found >= sk->nr_items)
|
||||
break;
|
||||
|
||||
}
|
||||
ret = 0;
|
||||
err:
|
||||
sk->nr_items = num_found;
|
||||
btrfs_free_path(path);
|
||||
return ret;
|
||||
}
|
||||
|
||||
static noinline int btrfs_ioctl_tree_search(struct file *file,
|
||||
void __user *argp)
|
||||
{
|
||||
struct btrfs_ioctl_search_args *args;
|
||||
struct inode *inode;
|
||||
int ret;
|
||||
|
||||
if (!capable(CAP_SYS_ADMIN))
|
||||
return -EPERM;
|
||||
|
||||
args = kmalloc(sizeof(*args), GFP_KERNEL);
|
||||
if (!args)
|
||||
return -ENOMEM;
|
||||
|
||||
if (copy_from_user(args, argp, sizeof(*args))) {
|
||||
kfree(args);
|
||||
return -EFAULT;
|
||||
}
|
||||
inode = fdentry(file)->d_inode;
|
||||
ret = search_ioctl(inode, args);
|
||||
if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
|
||||
ret = -EFAULT;
|
||||
kfree(args);
|
||||
return ret;
|
||||
}
|
||||
|
||||
/*
|
||||
Search INODE_REFs to identify path name of 'dirid' directory
|
||||
in a 'tree_id' tree. and sets path name to 'name'.
|
||||
*/
|
||||
* Search INODE_REFs to identify path name of 'dirid' directory
|
||||
* in a 'tree_id' tree. and sets path name to 'name'.
|
||||
*/
|
||||
static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
|
||||
u64 tree_id, u64 dirid, char *name)
|
||||
{
|
||||
struct btrfs_root *root;
|
||||
struct btrfs_key key;
|
||||
char *name_stack, *ptr;
|
||||
char *ptr;
|
||||
int ret = -1;
|
||||
int slot;
|
||||
int len;
|
||||
|
|
@ -771,13 +961,7 @@ static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
|
|||
if (!path)
|
||||
return -ENOMEM;
|
||||
|
||||
name_stack = kzalloc(BTRFS_PATH_NAME_MAX+1, GFP_NOFS);
|
||||
if (!name_stack) {
|
||||
btrfs_free_path(path);
|
||||
return -ENOMEM;
|
||||
}
|
||||
|
||||
ptr = &name_stack[BTRFS_PATH_NAME_MAX];
|
||||
ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX];
|
||||
|
||||
key.objectid = tree_id;
|
||||
key.type = BTRFS_ROOT_ITEM_KEY;
|
||||
|
|
@ -802,14 +986,16 @@ static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
|
|||
btrfs_item_key_to_cpu(l, &key, slot);
|
||||
|
||||
if (ret > 0 && (key.objectid != dirid ||
|
||||
key.type != BTRFS_INODE_REF_KEY))
|
||||
key.type != BTRFS_INODE_REF_KEY)) {
|
||||
ret = -ENOENT;
|
||||
goto out;
|
||||
}
|
||||
|
||||
iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
|
||||
len = btrfs_inode_ref_name_len(l, iref);
|
||||
ptr -= len + 1;
|
||||
total_len += len + 1;
|
||||
if (ptr < name_stack)
|
||||
if (ptr < name)
|
||||
goto out;
|
||||
|
||||
*(ptr + len) = '/';
|
||||
|
|
@ -824,14 +1010,41 @@ static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
|
|||
dirid = key.objectid;
|
||||
|
||||
}
|
||||
if (ptr < name_stack)
|
||||
if (ptr < name)
|
||||
goto out;
|
||||
strncpy(name, ptr, total_len);
|
||||
memcpy(name, ptr, total_len);
|
||||
name[total_len]='\0';
|
||||
ret = 0;
|
||||
out:
|
||||
btrfs_free_path(path);
|
||||
kfree(name_stack);
|
||||
return ret;
|
||||
}
|
||||
|
||||
static noinline int btrfs_ioctl_ino_lookup(struct file *file,
|
||||
void __user *argp)
|
||||
{
|
||||
struct btrfs_ioctl_ino_lookup_args *args;
|
||||
struct inode *inode;
|
||||
int ret;
|
||||
|
||||
if (!capable(CAP_SYS_ADMIN))
|
||||
return -EPERM;
|
||||
|
||||
args = kmalloc(sizeof(*args), GFP_KERNEL);
|
||||
if (copy_from_user(args, argp, sizeof(*args))) {
|
||||
kfree(args);
|
||||
return -EFAULT;
|
||||
}
|
||||
inode = fdentry(file)->d_inode;
|
||||
|
||||
ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
|
||||
args->treeid, args->objectid,
|
||||
args->name);
|
||||
|
||||
if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
|
||||
ret = -EFAULT;
|
||||
|
||||
kfree(args);
|
||||
return ret;
|
||||
}
|
||||
|
||||
|
|
@ -1430,6 +1643,10 @@ long btrfs_ioctl(struct file *file, unsigned int
|
|||
return btrfs_ioctl_trans_start(file);
|
||||
case BTRFS_IOC_TRANS_END:
|
||||
return btrfs_ioctl_trans_end(file);
|
||||
case BTRFS_IOC_TREE_SEARCH:
|
||||
return btrfs_ioctl_tree_search(file, argp);
|
||||
case BTRFS_IOC_INO_LOOKUP:
|
||||
return btrfs_ioctl_ino_lookup(file, argp);
|
||||
case BTRFS_IOC_SYNC:
|
||||
btrfs_sync_fs(file->f_dentry->d_sb, 1);
|
||||
return 0;
|
||||
|
|
|
|||
|
|
@ -30,6 +30,68 @@ struct btrfs_ioctl_vol_args {
|
|||
char name[BTRFS_PATH_NAME_MAX + 1];
|
||||
};
|
||||
|
||||
#define BTRFS_INO_LOOKUP_PATH_MAX 4080
|
||||
struct btrfs_ioctl_ino_lookup_args {
|
||||
__u64 treeid;
|
||||
__u64 objectid;
|
||||
char name[BTRFS_INO_LOOKUP_PATH_MAX];
|
||||
};
|
||||
|
||||
struct btrfs_ioctl_search_key {
|
||||
/* which root are we searching. 0 is the tree of tree roots */
|
||||
__u64 tree_id;
|
||||
|
||||
/* keys returned will be >= min and <= max */
|
||||
__u64 min_objectid;
|
||||
__u64 max_objectid;
|
||||
|
||||
/* keys returned will be >= min and <= max */
|
||||
__u64 min_offset;
|
||||
__u64 max_offset;
|
||||
|
||||
/* max and min transids to search for */
|
||||
__u64 min_transid;
|
||||
__u64 max_transid;
|
||||
|
||||
/* keys returned will be >= min and <= max */
|
||||
__u32 min_type;
|
||||
__u32 max_type;
|
||||
|
||||
/*
|
||||
* how many items did userland ask for, and how many are we
|
||||
* returning
|
||||
*/
|
||||
__u32 nr_items;
|
||||
|
||||
/* align to 64 bits */
|
||||
__u32 unused;
|
||||
|
||||
/* some extra for later */
|
||||
__u64 unused1;
|
||||
__u64 unused2;
|
||||
__u64 unused3;
|
||||
__u64 unused4;
|
||||
};
|
||||
|
||||
struct btrfs_ioctl_search_header {
|
||||
__u64 transid;
|
||||
__u64 objectid;
|
||||
__u64 offset;
|
||||
__u32 type;
|
||||
__u32 len;
|
||||
};
|
||||
|
||||
#define BTRFS_SEARCH_ARGS_BUFSIZE (4096 - sizeof(struct btrfs_ioctl_search_key))
|
||||
/*
|
||||
* the buf is an array of search headers where
|
||||
* each header is followed by the actual item
|
||||
* the type field is expanded to 32 bits for alignment
|
||||
*/
|
||||
struct btrfs_ioctl_search_args {
|
||||
struct btrfs_ioctl_search_key key;
|
||||
char buf[BTRFS_SEARCH_ARGS_BUFSIZE];
|
||||
};
|
||||
|
||||
struct btrfs_ioctl_clone_range_args {
|
||||
__s64 src_fd;
|
||||
__u64 src_offset, src_length;
|
||||
|
|
@ -67,4 +129,8 @@ struct btrfs_ioctl_clone_range_args {
|
|||
struct btrfs_ioctl_vol_args)
|
||||
#define BTRFS_IOC_SNAP_DESTROY _IOW(BTRFS_IOCTL_MAGIC, 15, \
|
||||
struct btrfs_ioctl_vol_args)
|
||||
#define BTRFS_IOC_TREE_SEARCH _IOWR(BTRFS_IOCTL_MAGIC, 17, \
|
||||
struct btrfs_ioctl_search_args)
|
||||
#define BTRFS_IOC_INO_LOOKUP _IOWR(BTRFS_IOCTL_MAGIC, 18, \
|
||||
struct btrfs_ioctl_ino_lookup_args)
|
||||
#endif
|
||||
|
|
|
|||
Loading…
Reference in New Issue