Btrfs: mount ro and remount support
This patch adds mount ro and remount support. The main
changes in patch are: adding btrfs_remount and related
helper function; splitting the transaction related code
out of close_ctree into btrfs_commit_super; updating
allocator to properly handle read only block group.
Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 3b0e974..c599f0e 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1075,10 +1075,12 @@
kfree(root);
return ERR_PTR(ret);
}
- ret = btrfs_find_dead_roots(fs_info->tree_root,
- root->root_key.objectid, root);
- BUG_ON(ret);
-
+ if (!(fs_info->sb->s_flags & MS_RDONLY)) {
+ ret = btrfs_find_dead_roots(fs_info->tree_root,
+ root->root_key.objectid, root);
+ BUG_ON(ret);
+ btrfs_orphan_cleanup(root);
+ }
return root;
}
@@ -1700,7 +1702,8 @@
btrfs_read_block_groups(extent_root);
- fs_info->generation = btrfs_super_generation(disk_super) + 1;
+ fs_info->generation = generation + 1;
+ fs_info->last_trans_committed = generation;
fs_info->data_alloc_profile = (u64)-1;
fs_info->metadata_alloc_profile = (u64)-1;
fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
@@ -1715,6 +1718,9 @@
if (!fs_info->transaction_kthread)
goto fail_cleaner;
+ if (sb->s_flags & MS_RDONLY)
+ return tree_root;
+
if (btrfs_super_log_root(disk_super) != 0) {
u32 blocksize;
u64 bytenr = btrfs_super_log_root(disk_super);
@@ -1735,7 +1741,6 @@
ret = btrfs_recover_log_trees(log_tree_root);
BUG_ON(ret);
}
- fs_info->last_trans_committed = btrfs_super_generation(disk_super);
ret = btrfs_cleanup_reloc_trees(tree_root);
BUG_ON(ret);
@@ -1955,11 +1960,56 @@
return 0;
}
+int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
+{
+ u64 root_objectid = 0;
+ struct btrfs_root *gang[8];
+ int i;
+ int ret;
+
+ while (1) {
+ ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
+ (void **)gang, root_objectid,
+ ARRAY_SIZE(gang));
+ if (!ret)
+ break;
+ for (i = 0; i < ret; i++) {
+ root_objectid = gang[i]->root_key.objectid;
+ ret = btrfs_find_dead_roots(fs_info->tree_root,
+ root_objectid, gang[i]);
+ BUG_ON(ret);
+ btrfs_orphan_cleanup(gang[i]);
+ }
+ root_objectid++;
+ }
+ return 0;
+}
+
+int btrfs_commit_super(struct btrfs_root *root)
+{
+ struct btrfs_trans_handle *trans;
+ int ret;
+
+ mutex_lock(&root->fs_info->cleaner_mutex);
+ btrfs_clean_old_snapshots(root);
+ mutex_unlock(&root->fs_info->cleaner_mutex);
+ trans = btrfs_start_transaction(root, 1);
+ ret = btrfs_commit_transaction(trans, root);
+ BUG_ON(ret);
+ /* run commit again to drop the original snapshot */
+ trans = btrfs_start_transaction(root, 1);
+ btrfs_commit_transaction(trans, root);
+ ret = btrfs_write_and_wait_transaction(NULL, root);
+ BUG_ON(ret);
+
+ ret = write_ctree_super(NULL, root);
+ return ret;
+}
+
int close_ctree(struct btrfs_root *root)
{
- int ret;
- struct btrfs_trans_handle *trans;
struct btrfs_fs_info *fs_info = root->fs_info;
+ int ret;
fs_info->closing = 1;
smp_mb();
@@ -1967,16 +2017,12 @@
kthread_stop(root->fs_info->transaction_kthread);
kthread_stop(root->fs_info->cleaner_kthread);
- btrfs_clean_old_snapshots(root);
- trans = btrfs_start_transaction(root, 1);
- ret = btrfs_commit_transaction(trans, root);
- /* run commit again to drop the original snapshot */
- trans = btrfs_start_transaction(root, 1);
- btrfs_commit_transaction(trans, root);
- ret = btrfs_write_and_wait_transaction(NULL, root);
- BUG_ON(ret);
-
- write_ctree_super(NULL, root);
+ if (!(fs_info->sb->s_flags & MS_RDONLY)) {
+ ret = btrfs_commit_super(root);
+ if (ret) {
+ printk("btrfs: commit super returns %d\n", ret);
+ }
+ }
if (fs_info->delalloc_bytes) {
printk("btrfs: at unmount delalloc count %Lu\n",
@@ -2000,12 +2046,10 @@
free_extent_buffer(root->fs_info->dev_root->node);
btrfs_free_block_groups(root->fs_info);
- fs_info->closing = 2;
+
del_fs_roots(fs_info);
- filemap_write_and_wait(fs_info->btree_inode->i_mapping);
-
- truncate_inode_pages(fs_info->btree_inode->i_mapping, 0);
+ iput(fs_info->btree_inode);
btrfs_stop_workers(&fs_info->fixup_workers);
btrfs_stop_workers(&fs_info->delalloc_workers);
@@ -2014,7 +2058,6 @@
btrfs_stop_workers(&fs_info->endio_write_workers);
btrfs_stop_workers(&fs_info->submit_workers);
- iput(fs_info->btree_inode);
#if 0
while(!list_empty(&fs_info->hashers)) {
struct btrfs_hasher *hasher;
