Btrfs: Add mount -o degraded to allow mounts to continue with missing devices
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 574b124..38b0d9e 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -614,21 +614,6 @@
return ret;
}
-static int close_all_devices(struct btrfs_fs_info *fs_info)
-{
- struct list_head *list;
- struct list_head *next;
- struct btrfs_device *device;
-
- list = &fs_info->fs_devices->devices;
- list_for_each(next, list) {
- device = list_entry(next, struct btrfs_device, dev_list);
- close_bdev_excl(device->bdev);
- device->bdev = NULL;
- }
- return 0;
-}
-
struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
u64 bytenr, u32 blocksize)
{
@@ -927,6 +912,8 @@
list_for_each(cur, &info->fs_devices->devices) {
device = list_entry(cur, struct btrfs_device, dev_list);
+ if (!device->bdev)
+ continue;
bdi = blk_get_backing_dev_info(device->bdev);
if (bdi && bdi_congested(bdi, bdi_bits)) {
ret = 1;
@@ -1140,7 +1127,8 @@
}
struct btrfs_root *open_ctree(struct super_block *sb,
- struct btrfs_fs_devices *fs_devices)
+ struct btrfs_fs_devices *fs_devices,
+ char *options)
{
u32 sectorsize;
u32 nodesize;
@@ -1276,12 +1264,19 @@
if (!btrfs_super_root(disk_super))
goto fail_sb_buffer;
- if (btrfs_super_num_devices(disk_super) != fs_devices->num_devices) {
+ btrfs_parse_options(options, tree_root, NULL);
+
+ if (btrfs_super_num_devices(disk_super) > fs_devices->num_devices) {
printk("Btrfs: wanted %llu devices, but found %llu\n",
(unsigned long long)btrfs_super_num_devices(disk_super),
(unsigned long long)fs_devices->num_devices);
- goto fail_sb_buffer;
+ 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);
nodesize = btrfs_super_nodesize(disk_super);
@@ -1329,6 +1324,8 @@
ret = btrfs_read_chunk_tree(chunk_root);
BUG_ON(ret);
+ btrfs_close_extra_devices(fs_devices);
+
blocksize = btrfs_level_size(tree_root,
btrfs_super_root_level(disk_super));
@@ -1374,7 +1371,7 @@
fail_iput:
iput(fs_info->btree_inode);
fail:
- close_all_devices(fs_info);
+ btrfs_close_devices(fs_info->fs_devices);
btrfs_mapping_tree_free(&fs_info->mapping_tree);
kfree(extent_root);
@@ -1429,6 +1426,13 @@
dev_item = &sb->dev_item;
list_for_each(cur, head) {
dev = list_entry(cur, struct btrfs_device, dev_list);
+ if (!dev->bdev) {
+ total_errors++;
+ continue;
+ }
+ if (!dev->in_fs_metadata)
+ continue;
+
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);
@@ -1482,6 +1486,11 @@
list_for_each(cur, head) {
dev = list_entry(cur, struct btrfs_device, dev_list);
+ if (!dev->bdev)
+ continue;
+ if (!dev->in_fs_metadata)
+ continue;
+
BUG_ON(!dev->pending_io);
bh = dev->pending_io;
wait_on_buffer(bh);
@@ -1631,7 +1640,7 @@
kfree(hasher);
}
#endif
- close_all_devices(fs_info);
+ btrfs_close_devices(fs_info->fs_devices);
btrfs_mapping_tree_free(&fs_info->mapping_tree);
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,23)