Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux...

[linux.git] / fs / btrfs / file.c

diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index f76b1fd160d446fb4c92fd56b8cc0ea14acc6f9a..aeb84469d2c4c0621b002084617578f7ac5f49b1 100644 (file)
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -293,15 +293,24 @@ static int __btrfs_run_defrag_inode(struct btrfs_fs_info *fs_info,
        struct btrfs_key key;
        struct btrfs_ioctl_defrag_range_args range;
        int num_defrag;
+       int index;
+       int ret;
 
        /* get the inode */
        key.objectid = defrag->root;
        btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
        key.offset = (u64)-1;
+
+       index = srcu_read_lock(&fs_info->subvol_srcu);
+
        inode_root = btrfs_read_fs_root_no_name(fs_info, &key);
        if (IS_ERR(inode_root)) {
-               kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
-               return PTR_ERR(inode_root);
+               ret = PTR_ERR(inode_root);
+               goto cleanup;
+       }
+       if (btrfs_root_refs(&inode_root->root_item) == 0) {
+               ret = -ENOENT;
+               goto cleanup;
        }
 
        key.objectid = defrag->ino;
@@ -309,9 +318,10 @@ static int __btrfs_run_defrag_inode(struct btrfs_fs_info *fs_info,
        key.offset = 0;
        inode = btrfs_iget(fs_info->sb, &key, inode_root, NULL);
        if (IS_ERR(inode)) {
-               kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
-               return PTR_ERR(inode);
+               ret = PTR_ERR(inode);
+               goto cleanup;
        }
+       srcu_read_unlock(&fs_info->subvol_srcu, index);
 
        /* do a chunk of defrag */
        clear_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags);
@@ -346,6 +356,10 @@ static int __btrfs_run_defrag_inode(struct btrfs_fs_info *fs_info,
 
        iput(inode);
        return 0;
+cleanup:
+       srcu_read_unlock(&fs_info->subvol_srcu, index);
+       kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
+       return ret;
 }
 
 /*
@@ -1594,9 +1608,10 @@ static ssize_t btrfs_file_aio_write(struct kiocb *iocb,
                if (err < 0 && num_written > 0)
                        num_written = err;
        }
-out:
+
        if (sync)
                atomic_dec(&BTRFS_I(inode)->sync_writers);
+out:
        sb_end_write(inode->i_sb);
        current->backing_dev_info = NULL;
        return num_written ? num_written : err;