1 files changed, 35 insertions, 21 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index c599f0ee997a..82833e5d84b6 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -345,6 +345,25 @@ out:
         return 0;
 }
 
+static int check_tree_block_fsid(struct btrfs_root *root,
+                                 struct extent_buffer *eb)
+{
+        struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
+        u8 fsid[BTRFS_UUID_SIZE];
+        int ret = 1;
+
+        read_extent_buffer(eb, fsid, (unsigned long)btrfs_header_fsid(eb),
+                           BTRFS_FSID_SIZE);
+        while (fs_devices) {
+                if (!memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE)) {
+                        ret = 0;
+                        break;
+                }
+                fs_devices = fs_devices->seed;
+        }
+        return ret;
+}
+
 int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
                                struct extent_state *state)
 {
@@ -382,9 +401,7 @@ int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
                 ret = -EIO;
                 goto err;
         }
-        if (memcmp_extent_buffer(eb, root->fs_info->fsid,
-                                 (unsigned long)btrfs_header_fsid(eb),
-                                 BTRFS_FSID_SIZE)) {
+        if (check_tree_block_fsid(root, eb)) {
                 printk("bad fsid on block %Lu\n", eb->start);
                 ret = -EIO;
                 goto err;
@@ -1558,9 +1575,11 @@ struct btrfs_root *open_ctree(struct super_block *sb,
         if (!btrfs_super_root(disk_super))
                 goto fail_sb_buffer;
 
-        err = btrfs_parse_options(tree_root, options);
-        if (err)
+        ret = btrfs_parse_options(tree_root, options);
+        if (ret) {
+                err = ret;
                 goto fail_sb_buffer;
+        }
 
         /*
          * we need to start all the end_io workers up front because the
@@ -1610,18 +1629,6 @@ struct btrfs_root *open_ctree(struct super_block *sb,
         btrfs_start_workers(&fs_info->endio_write_workers,
                             fs_info->thread_pool_size);
 
-        err = -EINVAL;
-        if (btrfs_super_num_devices(disk_super) > fs_devices->open_devices) {
-                printk("Btrfs: wanted %llu devices, but found %llu\n",
-                       (unsigned long long)btrfs_super_num_devices(disk_super),
-                       (unsigned long long)fs_devices->open_devices);
-                if (btrfs_test_opt(tree_root, DEGRADED))
-                        printk("continuing in degraded mode\n");
-                else {
-                        goto fail_sb_buffer;
-                }
-        }
-
         fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
         fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages,
                                     4 * 1024 * 1024 / PAGE_CACHE_SIZE);
@@ -1672,7 +1679,10 @@ struct btrfs_root *open_ctree(struct super_block *sb,
         mutex_lock(&fs_info->chunk_mutex);
         ret = btrfs_read_chunk_tree(chunk_root);
         mutex_unlock(&fs_info->chunk_mutex);
-        BUG_ON(ret);
+        if (ret) {
+                printk("btrfs: failed to read chunk tree on %s\n", sb->s_id);
+                goto fail_chunk_root;
+        }
 
         btrfs_close_extra_devices(fs_devices);
 
@@ -1684,7 +1694,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
                                           btrfs_super_root(disk_super),
                                           blocksize, generation);
         if (!tree_root->node)
-                goto fail_sb_buffer;
+                goto fail_chunk_root;
 
 
         ret = find_and_setup_root(tree_root, fs_info,
@@ -1753,6 +1763,8 @@ fail_extent_root:
         free_extent_buffer(extent_root->node);
 fail_tree_root:
         free_extent_buffer(tree_root->node);
+fail_chunk_root:
+        free_extent_buffer(chunk_root->node);
 fail_sys_array:
 fail_sb_buffer:
         btrfs_stop_workers(&fs_info->fixup_workers);
@@ -1823,9 +1835,10 @@ int write_all_supers(struct btrfs_root *root)
                         total_errors++;
                         continue;
                 }
-                if (!dev->in_fs_metadata)
+                if (!dev->in_fs_metadata || !dev->writeable)
                         continue;
 
+                btrfs_set_stack_device_generation(dev_item, 0);
                 btrfs_set_stack_device_type(dev_item, dev->type);
                 btrfs_set_stack_device_id(dev_item, dev->devid);
                 btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes);
@@ -1834,6 +1847,7 @@ int write_all_supers(struct btrfs_root *root)
                 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
                 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
                 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
+                memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
                 flags = btrfs_super_flags(sb);
                 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
 
@@ -1881,7 +1895,7 @@ int write_all_supers(struct btrfs_root *root)
                 dev = list_entry(cur, struct btrfs_device, dev_list);
                 if (!dev->bdev)
                         continue;
-                if (!dev->in_fs_metadata)
+                if (!dev->in_fs_metadata || !dev->writeable)
                         continue;
 
                 BUG_ON(!dev->pending_io);