1 files changed, 69 insertions, 23 deletions

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 0cb88f8146ea..de1793ba004a 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -280,6 +280,14 @@ static struct extent_buffer *buffer_search(struct extent_io_tree *tree,
         return NULL;
 }
 
+static void merge_cb(struct extent_io_tree *tree, struct extent_state *new,
+                     struct extent_state *other)
+{
+        if (tree->ops && tree->ops->merge_extent_hook)
+                tree->ops->merge_extent_hook(tree->mapping->host, new,
+                                             other);
+}
+
 /*
  * utility function to look for merge candidates inside a given range.
  * Any extents with matching state are merged together into a single
@@ -303,6 +311,7 @@ static int merge_state(struct extent_io_tree *tree,
                 other = rb_entry(other_node, struct extent_state, rb_node);
                 if (other->end == state->start - 1 &&
                     other->state == state->state) {
+                        merge_cb(tree, state, other);
                         state->start = other->start;
                         other->tree = NULL;
                         rb_erase(&other->rb_node, &tree->state);
@@ -314,33 +323,37 @@ static int merge_state(struct extent_io_tree *tree,
                 other = rb_entry(other_node, struct extent_state, rb_node);
                 if (other->start == state->end + 1 &&
                     other->state == state->state) {
+                        merge_cb(tree, state, other);
                         other->start = state->start;
                         state->tree = NULL;
                         rb_erase(&state->rb_node, &tree->state);
                         free_extent_state(state);
+                        state = NULL;
                 }
         }
+
         return 0;
 }
 
-static void set_state_cb(struct extent_io_tree *tree,
+static int set_state_cb(struct extent_io_tree *tree,
                          struct extent_state *state,
                          unsigned long bits)
 {
         if (tree->ops && tree->ops->set_bit_hook) {
-                tree->ops->set_bit_hook(tree->mapping->host, state->start,
-                                        state->end, state->state, bits);
+                return tree->ops->set_bit_hook(tree->mapping->host,
+                                               state->start, state->end,
+                                               state->state, bits);
         }
+
+        return 0;
 }
 
 static void clear_state_cb(struct extent_io_tree *tree,
                            struct extent_state *state,
                            unsigned long bits)
 {
-        if (tree->ops && tree->ops->clear_bit_hook) {
-                tree->ops->clear_bit_hook(tree->mapping->host, state->start,
-                                          state->end, state->state, bits);
-        }
+        if (tree->ops && tree->ops->clear_bit_hook)
+                tree->ops->clear_bit_hook(tree->mapping->host, state, bits);
 }
 
 /*
@@ -358,6 +371,7 @@ static int insert_state(struct extent_io_tree *tree,
                         int bits)
 {
         struct rb_node *node;
+        int ret;
 
         if (end < start) {
                 printk(KERN_ERR "btrfs end < start %llu %llu\n",
@@ -365,11 +379,14 @@ static int insert_state(struct extent_io_tree *tree,
                        (unsigned long long)start);
                 WARN_ON(1);
         }
-        if (bits & EXTENT_DIRTY)
-                tree->dirty_bytes += end - start + 1;
         state->start = start;
         state->end = end;
-        set_state_cb(tree, state, bits);
+        ret = set_state_cb(tree, state, bits);
+        if (ret)
+                return ret;
+
+        if (bits & EXTENT_DIRTY)
+                tree->dirty_bytes += end - start + 1;
         state->state |= bits;
         node = tree_insert(&tree->state, end, &state->rb_node);
         if (node) {
@@ -387,6 +404,15 @@ static int insert_state(struct extent_io_tree *tree,
         return 0;
 }
 
+static int split_cb(struct extent_io_tree *tree, struct extent_state *orig,
+                     u64 split)
+{
+        if (tree->ops && tree->ops->split_extent_hook)
+                return tree->ops->split_extent_hook(tree->mapping->host,
+                                                    orig, split);
+        return 0;
+}
+
 /*
  * split a given extent state struct in two, inserting the preallocated
  * struct 'prealloc' as the newly created second half.  'split' indicates an
@@ -405,6 +431,9 @@ static int split_state(struct extent_io_tree *tree, struct extent_state *orig,
                        struct extent_state *prealloc, u64 split)
 {
         struct rb_node *node;
+
+        split_cb(tree, orig, split);
+
         prealloc->start = orig->start;
         prealloc->end = split - 1;
         prealloc->state = orig->state;
@@ -542,8 +571,8 @@ hit_next:
                 if (err)
                         goto out;
                 if (state->end <= end) {
-                        set |= clear_state_bit(tree, state, bits,
-                                        wake, delete);
+                        set |= clear_state_bit(tree, state, bits, wake,
+                                               delete);
                         if (last_end == (u64)-1)
                                 goto out;
                         start = last_end + 1;
@@ -561,12 +590,11 @@ hit_next:
                         prealloc = alloc_extent_state(GFP_ATOMIC);
                 err = split_state(tree, state, prealloc, end + 1);
                 BUG_ON(err == -EEXIST);
-
                 if (wake)
                         wake_up(&state->wq);
 
-                set |= clear_state_bit(tree, prealloc, bits,
-                                       wake, delete);
+                set |= clear_state_bit(tree, prealloc, bits, wake, delete);
+
                 prealloc = NULL;
                 goto out;
         }
@@ -667,16 +695,23 @@ out:
         return 0;
 }
 
-static void set_state_bits(struct extent_io_tree *tree,
+static int set_state_bits(struct extent_io_tree *tree,
                            struct extent_state *state,
                            int bits)
 {
+        int ret;
+
+        ret = set_state_cb(tree, state, bits);
+        if (ret)
+                return ret;
+
         if ((bits & EXTENT_DIRTY) && !(state->state & EXTENT_DIRTY)) {
                 u64 range = state->end - state->start + 1;
                 tree->dirty_bytes += range;
         }
-        set_state_cb(tree, state, bits);
         state->state |= bits;
+
+        return 0;
 }
 
 static void cache_state(struct extent_state *state,
@@ -758,7 +793,10 @@ hit_next:
                         goto out;
                 }
 
-                set_state_bits(tree, state, bits);
+                err = set_state_bits(tree, state, bits);
+                if (err)
+                        goto out;
+
                 cache_state(state, cached_state);
                 merge_state(tree, state);
                 if (last_end == (u64)-1)
@@ -805,7 +843,9 @@ hit_next:
                 if (err)
                         goto out;
                 if (state->end <= end) {
-                        set_state_bits(tree, state, bits);
+                        err = set_state_bits(tree, state, bits);
+                        if (err)
+                                goto out;
                         cache_state(state, cached_state);
                         merge_state(tree, state);
                         if (last_end == (u64)-1)
@@ -829,11 +869,13 @@ hit_next:
                         this_end = last_start - 1;
                 err = insert_state(tree, prealloc, start, this_end,
                                    bits);
-                cache_state(prealloc, cached_state);
-                prealloc = NULL;
                 BUG_ON(err == -EEXIST);
-                if (err)
+                if (err) {
+                        prealloc = NULL;
                         goto out;
+                }
+                cache_state(prealloc, cached_state);
+                prealloc = NULL;
                 start = this_end + 1;
                 goto search_again;
         }
@@ -852,7 +894,11 @@ hit_next:
                 err = split_state(tree, state, prealloc, end + 1);
                 BUG_ON(err == -EEXIST);
 
-                set_state_bits(tree, prealloc, bits);
+                err = set_state_bits(tree, prealloc, bits);
+                if (err) {
+                        prealloc = NULL;
+                        goto out;
+                }
                 cache_state(prealloc, cached_state);
                 merge_state(tree, prealloc);
                 prealloc = NULL;