Merge branch 'for-linus-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs

Pull btrfs cleanups and fixes from Chris Mason:
 "These are small cleanups, and also some fixes for our async worker
  thread initialization.

  I was having some trouble testing these, but it ended up being a
  combination of changing around my test servers and a shiny new
  schedule while atomic from the new start/finish_plug in
  writeback_sb_inodes().

  That one only hits on btrfs raid5/6 or MD raid10, and if I wasn't
  changing a bunch of things in my test setup at once it would have been
  really clear.  Fix for writeback_sb_inodes() on the way as well"

* 'for-linus-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: cleanup: remove unnecessary check before btrfs_free_path is called
  btrfs: async_thread: Fix workqueue 'max_active' value when initializing
  btrfs: Add raid56 support for updating  num_tolerated_disk_barrier_failures in btrfs_balance
  btrfs: Cleanup for btrfs_calc_num_tolerated_disk_barrier_failures
  btrfs: Remove noused chunk_tree and chunk_objectid from scrub_enumerate_chunks and scrub_chunk
  btrfs: Update out-of-date "skip parity stripe" comment

1 files changed, 36 insertions, 40 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 9ebd34f1c677..0d98aee34fee 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -3443,6 +3443,26 @@ 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)
 {
@@ -3452,13 +3472,12 @@ 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;
@@ -3476,44 +3495,21 @@ 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);
         }