Btrfs: remove unnecessary locking of cleaner_mutex to avoid deadlock

[cascardo/linux.git] / fs / btrfs / disk-io.c

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 230546b..aa59871 100644 (file)
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -3440,6 +3440,26 @@ static int barrier_all_devices(struct btrfs_fs_info *info)
        return 0;
 }
 
+int btrfs_get_num_tolerated_disk_barrier_failures(u64 flags)
+{
+       if ((flags & (BTRFS_BLOCK_GROUP_DUP |
+                     BTRFS_BLOCK_GROUP_RAID0 |
+                     BTRFS_AVAIL_ALLOC_BIT_SINGLE)) ||
+           ((flags & BTRFS_BLOCK_GROUP_PROFILE_MASK) == 0))
+               return 0;
+
+       if (flags & (BTRFS_BLOCK_GROUP_RAID1 |
+                    BTRFS_BLOCK_GROUP_RAID5 |
+                    BTRFS_BLOCK_GROUP_RAID10))
+               return 1;
+
+       if (flags & BTRFS_BLOCK_GROUP_RAID6)
+               return 2;
+
+       pr_warn("BTRFS: unknown raid type: %llu\n", flags);
+       return 0;
+}
+
 int btrfs_calc_num_tolerated_disk_barrier_failures(
        struct btrfs_fs_info *fs_info)
 {
@@ -3449,13 +3469,12 @@ int btrfs_calc_num_tolerated_disk_barrier_failures(
                       BTRFS_BLOCK_GROUP_SYSTEM,
                       BTRFS_BLOCK_GROUP_METADATA,
                       BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA};
-       int num_types = 4;
        int i;
        int c;
        int num_tolerated_disk_barrier_failures =
                (int)fs_info->fs_devices->num_devices;
 
-       for (i = 0; i < num_types; i++) {
+       for (i = 0; i < ARRAY_SIZE(types); i++) {
                struct btrfs_space_info *tmp;
 
                sinfo = NULL;
@@ -3473,44 +3492,21 @@ int btrfs_calc_num_tolerated_disk_barrier_failures(
 
                down_read(&sinfo->groups_sem);
                for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
-                       if (!list_empty(&sinfo->block_groups[c])) {
-                               u64 flags;
-
-                               btrfs_get_block_group_info(
-                                       &sinfo->block_groups[c], &space);
-                               if (space.total_bytes == 0 ||
-                                   space.used_bytes == 0)
-                                       continue;
-                               flags = space.flags;
-                               /*
-                                * return
-                                * 0: if dup, single or RAID0 is configured for
-                                *    any of metadata, system or data, else
-                                * 1: if RAID5 is configured, or if RAID1 or
-                                *    RAID10 is configured and only two mirrors
-                                *    are used, else
-                                * 2: if RAID6 is configured, else
-                                * num_mirrors - 1: if RAID1 or RAID10 is
-                                *                  configured and more than
-                                *                  2 mirrors are used.
-                                */
-                               if (num_tolerated_disk_barrier_failures > 0 &&
-                                   ((flags & (BTRFS_BLOCK_GROUP_DUP |
-                                              BTRFS_BLOCK_GROUP_RAID0)) ||
-                                    ((flags & BTRFS_BLOCK_GROUP_PROFILE_MASK)
-                                     == 0)))
-                                       num_tolerated_disk_barrier_failures = 0;
-                               else if (num_tolerated_disk_barrier_failures > 1) {
-                                       if (flags & (BTRFS_BLOCK_GROUP_RAID1 |
-                                           BTRFS_BLOCK_GROUP_RAID5 |
-                                           BTRFS_BLOCK_GROUP_RAID10)) {
-                                               num_tolerated_disk_barrier_failures = 1;
-                                       } else if (flags &
-                                                  BTRFS_BLOCK_GROUP_RAID6) {
-                                               num_tolerated_disk_barrier_failures = 2;
-                                       }
-                               }
-                       }
+                       u64 flags;
+
+                       if (list_empty(&sinfo->block_groups[c]))
+                               continue;
+
+                       btrfs_get_block_group_info(&sinfo->block_groups[c],
+                                                  &space);
+                       if (space.total_bytes == 0 || space.used_bytes == 0)
+                               continue;
+                       flags = space.flags;
+
+                       num_tolerated_disk_barrier_failures = min(
+                               num_tolerated_disk_barrier_failures,
+                               btrfs_get_num_tolerated_disk_barrier_failures(
+                                       flags));
                }
                up_read(&sinfo->groups_sem);
        }
@@ -3761,6 +3757,13 @@ void close_ctree(struct btrfs_root *root)
        cancel_work_sync(&fs_info->async_reclaim_work);
 
        if (!(fs_info->sb->s_flags & MS_RDONLY)) {
+               /*
+                * If the cleaner thread is stopped and there are
+                * block groups queued for removal, the deletion will be
+                * skipped when we quit the cleaner thread.
+                */
+               btrfs_delete_unused_bgs(root->fs_info);
+
                ret = btrfs_commit_super(root);
                if (ret)
                        btrfs_err(fs_info, "commit super ret %d", ret);