Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block into for-3.18

This is to receive 0a30288da1ae ("blk-mq, percpu_ref: implement a
kludge for SCSI blk-mq stall during probe") which implements
__percpu_ref_kill_expedited() to work around SCSI blk-mq stall.  The
commit reverted and patches to implement proper fix will be added.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@lst.de>

1 files changed, 278 insertions, 30 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 94ec71eda86b..caaf015d6e4b 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -552,7 +552,8 @@ static int cache_block_group(struct btrfs_block_group_cache *cache,
         caching_ctl->block_group = cache;
         caching_ctl->progress = cache->key.objectid;
         atomic_set(&caching_ctl->count, 1);
-        btrfs_init_work(&caching_ctl->work, caching_thread, NULL, NULL);
+        btrfs_init_work(&caching_ctl->work, btrfs_cache_helper,
+                        caching_thread, NULL, NULL);
 
         spin_lock(&cache->lock);
         /*
@@ -2749,8 +2750,8 @@ int btrfs_async_run_delayed_refs(struct btrfs_root *root,
                 async->sync = 0;
         init_completion(&async->wait);
 
-        btrfs_init_work(&async->work, delayed_ref_async_start,
-                        NULL, NULL);
+        btrfs_init_work(&async->work, btrfs_extent_refs_helper,
+                        delayed_ref_async_start, NULL, NULL);
 
         btrfs_queue_work(root->fs_info->extent_workers, &async->work);
 
@@ -3057,7 +3058,7 @@ out:
 static int __btrfs_mod_ref(struct btrfs_trans_handle *trans,
                            struct btrfs_root *root,
                            struct extent_buffer *buf,
-                           int full_backref, int inc, int no_quota)
+                           int full_backref, int inc)
 {
         u64 bytenr;
         u64 num_bytes;
@@ -3111,7 +3112,7 @@ static int __btrfs_mod_ref(struct btrfs_trans_handle *trans,
                         key.offset -= btrfs_file_extent_offset(buf, fi);
                         ret = process_func(trans, root, bytenr, num_bytes,
                                            parent, ref_root, key.objectid,
-                                           key.offset, no_quota);
+                                           key.offset, 1);
                         if (ret)
                                 goto fail;
                 } else {
@@ -3119,7 +3120,7 @@ static int __btrfs_mod_ref(struct btrfs_trans_handle *trans,
                         num_bytes = btrfs_level_size(root, level - 1);
                         ret = process_func(trans, root, bytenr, num_bytes,
                                            parent, ref_root, level - 1, 0,
-                                           no_quota);
+                                           1);
                         if (ret)
                                 goto fail;
                 }
@@ -3130,15 +3131,15 @@ fail:
 }
 
 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
-                  struct extent_buffer *buf, int full_backref, int no_quota)
+                  struct extent_buffer *buf, int full_backref)
 {
-        return __btrfs_mod_ref(trans, root, buf, full_backref, 1, no_quota);
+        return __btrfs_mod_ref(trans, root, buf, full_backref, 1);
 }
 
 int btrfs_dec_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
-                  struct extent_buffer *buf, int full_backref, int no_quota)
+                  struct extent_buffer *buf, int full_backref)
 {
-        return __btrfs_mod_ref(trans, root, buf, full_backref, 0, no_quota);
+        return __btrfs_mod_ref(trans, root, buf, full_backref, 0);
 }
 
 static int write_one_cache_group(struct btrfs_trans_handle *trans,
@@ -3586,13 +3587,7 @@ static u64 get_restripe_target(struct btrfs_fs_info *fs_info, u64 flags)
  */
 static u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags)
 {
-        /*
-         * we add in the count of missing devices because we want
-         * to make sure that any RAID levels on a degraded FS
-         * continue to be honored.
-         */
-        u64 num_devices = root->fs_info->fs_devices->rw_devices +
-                root->fs_info->fs_devices->missing_devices;
+        u64 num_devices = root->fs_info->fs_devices->rw_devices;
         u64 target;
         u64 tmp;
 
@@ -7478,6 +7473,220 @@ reada:
         wc->reada_slot = slot;
 }
 
+static int account_leaf_items(struct btrfs_trans_handle *trans,
+                              struct btrfs_root *root,
+                              struct extent_buffer *eb)
+{
+        int nr = btrfs_header_nritems(eb);
+        int i, extent_type, ret;
+        struct btrfs_key key;
+        struct btrfs_file_extent_item *fi;
+        u64 bytenr, num_bytes;
+
+        for (i = 0; i < nr; i++) {
+                btrfs_item_key_to_cpu(eb, &key, i);
+
+                if (key.type != BTRFS_EXTENT_DATA_KEY)
+                        continue;
+
+                fi = btrfs_item_ptr(eb, i, struct btrfs_file_extent_item);
+                /* filter out non qgroup-accountable extents  */
+                extent_type = btrfs_file_extent_type(eb, fi);
+
+                if (extent_type == BTRFS_FILE_EXTENT_INLINE)
+                        continue;
+
+                bytenr = btrfs_file_extent_disk_bytenr(eb, fi);
+                if (!bytenr)
+                        continue;
+
+                num_bytes = btrfs_file_extent_disk_num_bytes(eb, fi);
+
+                ret = btrfs_qgroup_record_ref(trans, root->fs_info,
+                                              root->objectid,
+                                              bytenr, num_bytes,
+                                              BTRFS_QGROUP_OPER_SUB_SUBTREE, 0);
+                if (ret)
+                        return ret;
+        }
+        return 0;
+}
+
+/*
+ * Walk up the tree from the bottom, freeing leaves and any interior
+ * nodes which have had all slots visited. If a node (leaf or
+ * interior) is freed, the node above it will have it's slot
+ * incremented. The root node will never be freed.
+ *
+ * At the end of this function, we should have a path which has all
+ * slots incremented to the next position for a search. If we need to
+ * read a new node it will be NULL and the node above it will have the
+ * correct slot selected for a later read.
+ *
+ * If we increment the root nodes slot counter past the number of
+ * elements, 1 is returned to signal completion of the search.
+ */
+static int adjust_slots_upwards(struct btrfs_root *root,
+                                struct btrfs_path *path, int root_level)
+{
+        int level = 0;
+        int nr, slot;
+        struct extent_buffer *eb;
+
+        if (root_level == 0)
+                return 1;
+
+        while (level <= root_level) {
+                eb = path->nodes[level];
+                nr = btrfs_header_nritems(eb);
+                path->slots[level]++;
+                slot = path->slots[level];
+                if (slot >= nr || level == 0) {
+                        /*
+                         * Don't free the root -  we will detect this
+                         * condition after our loop and return a
+                         * positive value for caller to stop walking the tree.
+                         */
+                        if (level != root_level) {
+                                btrfs_tree_unlock_rw(eb, path->locks[level]);
+                                path->locks[level] = 0;
+
+                                free_extent_buffer(eb);
+                                path->nodes[level] = NULL;
+                                path->slots[level] = 0;
+                        }
+                } else {
+                        /*
+                         * We have a valid slot to walk back down
+                         * from. Stop here so caller can process these
+                         * new nodes.
+                         */
+                        break;
+                }
+
+                level++;
+        }
+
+        eb = path->nodes[root_level];
+        if (path->slots[root_level] >= btrfs_header_nritems(eb))
+                return 1;
+
+        return 0;
+}
+
+/*
+ * root_eb is the subtree root and is locked before this function is called.
+ */
+static int account_shared_subtree(struct btrfs_trans_handle *trans,
+                                  struct btrfs_root *root,
+                                  struct extent_buffer *root_eb,
+                                  u64 root_gen,
+                                  int root_level)
+{
+        int ret = 0;
+        int level;
+        struct extent_buffer *eb = root_eb;
+        struct btrfs_path *path = NULL;
+
+        BUG_ON(root_level < 0 || root_level > BTRFS_MAX_LEVEL);
+        BUG_ON(root_eb == NULL);
+
+        if (!root->fs_info->quota_enabled)
+                return 0;
+
+        if (!extent_buffer_uptodate(root_eb)) {
+                ret = btrfs_read_buffer(root_eb, root_gen);
+                if (ret)
+                        goto out;
+        }
+
+        if (root_level == 0) {
+                ret = account_leaf_items(trans, root, root_eb);
+                goto out;
+        }
+
+        path = btrfs_alloc_path();
+        if (!path)
+                return -ENOMEM;
+
+        /*
+         * Walk down the tree.  Missing extent blocks are filled in as
+         * we go. Metadata is accounted every time we read a new
+         * extent block.
+         *
+         * When we reach a leaf, we account for file extent items in it,
+         * walk back up the tree (adjusting slot pointers as we go)
+         * and restart the search process.
+         */
+        extent_buffer_get(root_eb); /* For path */
+        path->nodes[root_level] = root_eb;
+        path->slots[root_level] = 0;
+        path->locks[root_level] = 0; /* so release_path doesn't try to unlock */
+walk_down:
+        level = root_level;
+        while (level >= 0) {
+                if (path->nodes[level] == NULL) {
+                        int child_bsize = root->nodesize;
+                        int parent_slot;
+                        u64 child_gen;
+                        u64 child_bytenr;
+
+                        /* We need to get child blockptr/gen from
+                         * parent before we can read it. */
+                        eb = path->nodes[level + 1];
+                        parent_slot = path->slots[level + 1];
+                        child_bytenr = btrfs_node_blockptr(eb, parent_slot);
+                        child_gen = btrfs_node_ptr_generation(eb, parent_slot);
+
+                        eb = read_tree_block(root, child_bytenr, child_bsize,
+                                             child_gen);
+                        if (!eb || !extent_buffer_uptodate(eb)) {
+                                ret = -EIO;
+                                goto out;
+                        }
+
+                        path->nodes[level] = eb;
+                        path->slots[level] = 0;
+
+                        btrfs_tree_read_lock(eb);
+                        btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
+                        path->locks[level] = BTRFS_READ_LOCK_BLOCKING;
+
+                        ret = btrfs_qgroup_record_ref(trans, root->fs_info,
+                                                root->objectid,
+                                                child_bytenr,
+                                                child_bsize,
+                                                BTRFS_QGROUP_OPER_SUB_SUBTREE,
+                                                0);
+                        if (ret)
+                                goto out;
+
+                }
+
+                if (level == 0) {
+                        ret = account_leaf_items(trans, root, path->nodes[level]);
+                        if (ret)
+                                goto out;
+
+                        /* Nonzero return here means we completed our search */
+                        ret = adjust_slots_upwards(root, path, root_level);
+                        if (ret)
+                                break;
+
+                        /* Restart search with new slots */
+                        goto walk_down;
+                }
+
+                level--;
+        }
+
+        ret = 0;
+out:
+        btrfs_free_path(path);
+
+        return ret;
+}
+
 /*
  * helper to process tree block while walking down the tree.
  *
@@ -7532,9 +7741,9 @@ static noinline int walk_down_proc(struct btrfs_trans_handle *trans,
         /* wc->stage == UPDATE_BACKREF */
         if (!(wc->flags[level] & flag)) {
                 BUG_ON(!path->locks[level]);
-                ret = btrfs_inc_ref(trans, root, eb, 1, wc->for_reloc);
+                ret = btrfs_inc_ref(trans, root, eb, 1);
                 BUG_ON(ret); /* -ENOMEM */
-                ret = btrfs_dec_ref(trans, root, eb, 0, wc->for_reloc);
+                ret = btrfs_dec_ref(trans, root, eb, 0);
                 BUG_ON(ret); /* -ENOMEM */
                 ret = btrfs_set_disk_extent_flags(trans, root, eb->start,
                                                   eb->len, flag,
@@ -7581,6 +7790,7 @@ static noinline int do_walk_down(struct btrfs_trans_handle *trans,
         int level = wc->level;
         int reada = 0;
         int ret = 0;
+        bool need_account = false;
 
         generation = btrfs_node_ptr_generation(path->nodes[level],
                                                path->slots[level]);
@@ -7626,6 +7836,7 @@ static noinline int do_walk_down(struct btrfs_trans_handle *trans,
 
         if (wc->stage == DROP_REFERENCE) {
                 if (wc->refs[level - 1] > 1) {
+                        need_account = true;
                         if (level == 1 &&
                             (wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF))
                                 goto skip;
@@ -7689,6 +7900,16 @@ skip:
                         parent = 0;
                 }
 
+                if (need_account) {
+                        ret = account_shared_subtree(trans, root, next,
+                                                     generation, level - 1);
+                        if (ret) {
+                                printk_ratelimited(KERN_ERR "BTRFS: %s Error "
+                                        "%d accounting shared subtree. Quota "
+                                        "is out of sync, rescan required.\n",
+                                        root->fs_info->sb->s_id, ret);
+                        }
+                }
                 ret = btrfs_free_extent(trans, root, bytenr, blocksize, parent,
                                 root->root_key.objectid, level - 1, 0, 0);
                 BUG_ON(ret); /* -ENOMEM */
@@ -7769,12 +7990,17 @@ static noinline int walk_up_proc(struct btrfs_trans_handle *trans,
         if (wc->refs[level] == 1) {
                 if (level == 0) {
                         if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
-                                ret = btrfs_dec_ref(trans, root, eb, 1,
-                                                    wc->for_reloc);
+                                ret = btrfs_dec_ref(trans, root, eb, 1);
                         else
-                                ret = btrfs_dec_ref(trans, root, eb, 0,
-                                                    wc->for_reloc);
+                                ret = btrfs_dec_ref(trans, root, eb, 0);
                         BUG_ON(ret); /* -ENOMEM */
+                        ret = account_leaf_items(trans, root, eb);
+                        if (ret) {
+                                printk_ratelimited(KERN_ERR "BTRFS: %s Error "
+                                        "%d accounting leaf items. Quota "
+                                        "is out of sync, rescan required.\n",
+                                        root->fs_info->sb->s_id, ret);
+                        }
                 }
                 /* make block locked assertion in clean_tree_block happy */
                 if (!path->locks[level] &&
@@ -7900,6 +8126,8 @@ int btrfs_drop_snapshot(struct btrfs_root *root,
         int level;
         bool root_dropped = false;
 
+        btrfs_debug(root->fs_info, "Drop subvolume %llu", root->objectid);
+
         path = btrfs_alloc_path();
         if (!path) {
                 err = -ENOMEM;
@@ -8025,6 +8253,24 @@ int btrfs_drop_snapshot(struct btrfs_root *root,
                                 goto out_end_trans;
                         }
 
+                        /*
+                         * Qgroup update accounting is run from
+                         * delayed ref handling. This usually works
+                         * out because delayed refs are normally the
+                         * only way qgroup updates are added. However,
+                         * we may have added updates during our tree
+                         * walk so run qgroups here to make sure we
+                         * don't lose any updates.
+                         */
+                        ret = btrfs_delayed_qgroup_accounting(trans,
+                                                              root->fs_info);
+                        if (ret)
+                                printk_ratelimited(KERN_ERR "BTRFS: Failure %d "
+                                                   "running qgroup updates "
+                                                   "during snapshot delete. "
+                                                   "Quota is out of sync, "
+                                                   "rescan required.\n", ret);
+
                         btrfs_end_transaction_throttle(trans, tree_root);
                         if (!for_reloc && btrfs_need_cleaner_sleep(root)) {
                                 pr_debug("BTRFS: drop snapshot early exit\n");
@@ -8078,6 +8324,14 @@ int btrfs_drop_snapshot(struct btrfs_root *root,
         }
         root_dropped = true;
 out_end_trans:
+        ret = btrfs_delayed_qgroup_accounting(trans, tree_root->fs_info);
+        if (ret)
+                printk_ratelimited(KERN_ERR "BTRFS: Failure %d "
+                                   "running qgroup updates "
+                                   "during snapshot delete. "
+                                   "Quota is out of sync, "
+                                   "rescan required.\n", ret);
+
         btrfs_end_transaction_throttle(trans, tree_root);
 out_free:
         kfree(wc);
@@ -8181,13 +8435,7 @@ static u64 update_block_group_flags(struct btrfs_root *root, u64 flags)
         if (stripped)
                 return extended_to_chunk(stripped);
 
-        /*
-         * we add in the count of missing devices because we want
-         * to make sure that any RAID levels on a degraded FS
-         * continue to be honored.
-         */
-        num_devices = root->fs_info->fs_devices->rw_devices +
-                root->fs_info->fs_devices->missing_devices;
+        num_devices = root->fs_info->fs_devices->rw_devices;
 
         stripped = BTRFS_BLOCK_GROUP_RAID0 |
                 BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6 |