]> git.karo-electronics.de Git - mv-sheeva.git/blobdiff - fs/btrfs/ioctl.c
Btrfs: add search and inode lookup ioctls
[mv-sheeva.git] / fs / btrfs / ioctl.c
index ac2a28f4fa1a7f00e8bc3d5890565eccf44a077e..c6044733198d0fa24599bebff9d6e1ee445382c9 100644 (file)
@@ -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;