btrfs: lift read-write mount setup from mount and remount
Mounting rw and remounting from ro to rw naturally share invariants and
functionality which result in a correctly setup rw filesystem. Luckily,
there is even a strong unity in the code which implements them. In
mount's open_ctree, these operations mostly happen after an early return
for ro file systems, and in remount, they happen in a section devoted to
remounting ro->rw, after some remount specific validation passes.
However, there are unfortunately a few differences. There are small
deviations in the order of some of the operations, remount does not
start orphan cleanup in root_tree or fs_tree, remount does not create
the free space tree, and remount does not handle "one-shot" mount
options like clear_cache and uuid tree rescan.
Since we want to add building the free space tree to remount, and also
to start the same orphan cleanup process on a filesystem mounted as ro
then remounted rw, we would benefit from unifying the logic between the
two code paths.
This patch only lifts the existing common functionality, and leaves a
natural path for fixing the discrepancies.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 455d924..49b4a16 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -1885,7 +1885,6 @@ static inline void btrfs_remount_cleanup(struct btrfs_fs_info *fs_info,
static int btrfs_remount(struct super_block *sb, int *flags, char *data)
{
struct btrfs_fs_info *fs_info = btrfs_sb(sb);
- struct btrfs_root *root = fs_info->tree_root;
unsigned old_flags = sb->s_flags;
unsigned long old_opts = fs_info->mount_opt;
unsigned long old_compress_type = fs_info->compress_type;
@@ -1978,39 +1977,15 @@ static int btrfs_remount(struct super_block *sb, int *flags, char *data)
goto restore;
}
- ret = btrfs_cleanup_fs_roots(fs_info);
+ /*
+ * NOTE: when remounting with a change that does writes, don't
+ * put it anywhere above this point, as we are not sure to be
+ * safe to write until we pass the above checks.
+ */
+ ret = btrfs_start_pre_rw_mount(fs_info);
if (ret)
goto restore;
- /* recover relocation */
- mutex_lock(&fs_info->cleaner_mutex);
- ret = btrfs_recover_relocation(root);
- mutex_unlock(&fs_info->cleaner_mutex);
- if (ret)
- goto restore;
-
- ret = btrfs_resume_balance_async(fs_info);
- if (ret)
- goto restore;
-
- ret = btrfs_resume_dev_replace_async(fs_info);
- if (ret) {
- btrfs_warn(fs_info, "failed to resume dev_replace");
- goto restore;
- }
-
- btrfs_qgroup_rescan_resume(fs_info);
-
- if (!fs_info->uuid_root) {
- btrfs_info(fs_info, "creating UUID tree");
- ret = btrfs_create_uuid_tree(fs_info);
- if (ret) {
- btrfs_warn(fs_info,
- "failed to create the UUID tree %d",
- ret);
- goto restore;
- }
- }
sb->s_flags &= ~SB_RDONLY;
set_bit(BTRFS_FS_OPEN, &fs_info->flags);