Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux...
[linux-2.6-block.git] / fs / btrfs / free-space-cache.c
index 202008ec367d4c4c2cfcf73f7289692dd910b25c..6c4e2baa9290e16d06a4a8dfc5c3b05880cfeb27 100644 (file)
@@ -33,6 +33,8 @@
 
 static int link_free_space(struct btrfs_free_space_ctl *ctl,
                           struct btrfs_free_space *info);
+static void unlink_free_space(struct btrfs_free_space_ctl *ctl,
+                             struct btrfs_free_space *info);
 
 static struct inode *__lookup_free_space_inode(struct btrfs_root *root,
                                               struct btrfs_path *path,
@@ -75,7 +77,8 @@ static struct inode *__lookup_free_space_inode(struct btrfs_root *root,
                return ERR_PTR(-ENOENT);
        }
 
-       inode->i_mapping->flags &= ~__GFP_FS;
+       mapping_set_gfp_mask(inode->i_mapping,
+                       mapping_gfp_mask(inode->i_mapping) & ~__GFP_FS);
 
        return inode;
 }
@@ -365,7 +368,7 @@ static int io_ctl_prepare_pages(struct io_ctl *io_ctl, struct inode *inode,
 
 static void io_ctl_set_generation(struct io_ctl *io_ctl, u64 generation)
 {
-       u64 *val;
+       __le64 *val;
 
        io_ctl_map_page(io_ctl, 1);
 
@@ -388,7 +391,7 @@ static void io_ctl_set_generation(struct io_ctl *io_ctl, u64 generation)
 
 static int io_ctl_check_generation(struct io_ctl *io_ctl, u64 generation)
 {
-       u64 *gen;
+       __le64 *gen;
 
        /*
         * Skip the crc area.  If we don't check crcs then we just have a 64bit
@@ -584,6 +587,44 @@ static int io_ctl_read_bitmap(struct io_ctl *io_ctl,
        return 0;
 }
 
+/*
+ * Since we attach pinned extents after the fact we can have contiguous sections
+ * of free space that are split up in entries.  This poses a problem with the
+ * tree logging stuff since it could have allocated across what appears to be 2
+ * entries since we would have merged the entries when adding the pinned extents
+ * back to the free space cache.  So run through the space cache that we just
+ * loaded and merge contiguous entries.  This will make the log replay stuff not
+ * blow up and it will make for nicer allocator behavior.
+ */
+static void merge_space_tree(struct btrfs_free_space_ctl *ctl)
+{
+       struct btrfs_free_space *e, *prev = NULL;
+       struct rb_node *n;
+
+again:
+       spin_lock(&ctl->tree_lock);
+       for (n = rb_first(&ctl->free_space_offset); n; n = rb_next(n)) {
+               e = rb_entry(n, struct btrfs_free_space, offset_index);
+               if (!prev)
+                       goto next;
+               if (e->bitmap || prev->bitmap)
+                       goto next;
+               if (prev->offset + prev->bytes == e->offset) {
+                       unlink_free_space(ctl, prev);
+                       unlink_free_space(ctl, e);
+                       prev->bytes += e->bytes;
+                       kmem_cache_free(btrfs_free_space_cachep, e);
+                       link_free_space(ctl, prev);
+                       prev = NULL;
+                       spin_unlock(&ctl->tree_lock);
+                       goto again;
+               }
+next:
+               prev = e;
+       }
+       spin_unlock(&ctl->tree_lock);
+}
+
 int __load_free_space_cache(struct btrfs_root *root, struct inode *inode,
                            struct btrfs_free_space_ctl *ctl,
                            struct btrfs_path *path, u64 offset)
@@ -726,6 +767,7 @@ int __load_free_space_cache(struct btrfs_root *root, struct inode *inode,
        }
 
        io_ctl_drop_pages(&io_ctl);
+       merge_space_tree(ctl);
        ret = 1;
 out:
        io_ctl_free(&io_ctl);
@@ -972,9 +1014,7 @@ int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
                goto out;
 
 
-       ret = filemap_write_and_wait(inode->i_mapping);
-       if (ret)
-               goto out;
+       btrfs_wait_ordered_range(inode, 0, (u64)-1);
 
        key.objectid = BTRFS_FREE_SPACE_OBJECTID;
        key.offset = offset;
@@ -1503,29 +1543,26 @@ again:
        end = bitmap_info->offset + (u64)(BITS_PER_BITMAP * ctl->unit) - 1;
 
        /*
-        * XXX - this can go away after a few releases.
-        *
-        * since the only user of btrfs_remove_free_space is the tree logging
-        * stuff, and the only way to test that is under crash conditions, we
-        * want to have this debug stuff here just in case somethings not
-        * working.  Search the bitmap for the space we are trying to use to
-        * make sure its actually there.  If its not there then we need to stop
-        * because something has gone wrong.
+        * We need to search for bits in this bitmap.  We could only cover some
+        * of the extent in this bitmap thanks to how we add space, so we need
+        * to search for as much as it as we can and clear that amount, and then
+        * go searching for the next bit.
         */
        search_start = *offset;
-       search_bytes = *bytes;
+       search_bytes = ctl->unit;
        search_bytes = min(search_bytes, end - search_start + 1);
        ret = search_bitmap(ctl, bitmap_info, &search_start, &search_bytes);
        BUG_ON(ret < 0 || search_start != *offset);
 
-       if (*offset > bitmap_info->offset && *offset + *bytes > end) {
-               bitmap_clear_bits(ctl, bitmap_info, *offset, end - *offset + 1);
-               *bytes -= end - *offset + 1;
-               *offset = end + 1;
-       } else if (*offset >= bitmap_info->offset && *offset + *bytes <= end) {
-               bitmap_clear_bits(ctl, bitmap_info, *offset, *bytes);
-               *bytes = 0;
-       }
+       /* We may have found more bits than what we need */
+       search_bytes = min(search_bytes, *bytes);
+
+       /* Cannot clear past the end of the bitmap */
+       search_bytes = min(search_bytes, end - search_start + 1);
+
+       bitmap_clear_bits(ctl, bitmap_info, search_start, search_bytes);
+       *offset += search_bytes;
+       *bytes -= search_bytes;
 
        if (*bytes) {
                struct rb_node *next = rb_next(&bitmap_info->offset_index);
@@ -1556,7 +1593,7 @@ again:
                 * everything over again.
                 */
                search_start = *offset;
-               search_bytes = *bytes;
+               search_bytes = ctl->unit;
                ret = search_bitmap(ctl, bitmap_info, &search_start,
                                    &search_bytes);
                if (ret < 0 || search_start != *offset)
@@ -1839,12 +1876,14 @@ int btrfs_remove_free_space(struct btrfs_block_group_cache *block_group,
 {
        struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
        struct btrfs_free_space *info;
-       struct btrfs_free_space *next_info = NULL;
        int ret = 0;
 
        spin_lock(&ctl->tree_lock);
 
 again:
+       if (!bytes)
+               goto out_lock;
+
        info = tree_search_offset(ctl, offset, 0, 0);
        if (!info) {
                /*
@@ -1865,88 +1904,48 @@ again:
                }
        }
 
-       if (info->bytes < bytes && rb_next(&info->offset_index)) {
-               u64 end;
-               next_info = rb_entry(rb_next(&info->offset_index),
-                                            struct btrfs_free_space,
-                                            offset_index);
-
-               if (next_info->bitmap)
-                       end = next_info->offset +
-                             BITS_PER_BITMAP * ctl->unit - 1;
-               else
-                       end = next_info->offset + next_info->bytes;
-
-               if (next_info->bytes < bytes ||
-                   next_info->offset > offset || offset > end) {
-                       printk(KERN_CRIT "Found free space at %llu, size %llu,"
-                             " trying to use %llu\n",
-                             (unsigned long long)info->offset,
-                             (unsigned long long)info->bytes,
-                             (unsigned long long)bytes);
-                       WARN_ON(1);
-                       ret = -EINVAL;
-                       goto out_lock;
-               }
-
-               info = next_info;
-       }
-
-       if (info->bytes == bytes) {
-               unlink_free_space(ctl, info);
-               if (info->bitmap) {
-                       kfree(info->bitmap);
-                       ctl->total_bitmaps--;
-               }
-               kmem_cache_free(btrfs_free_space_cachep, info);
-               ret = 0;
-               goto out_lock;
-       }
-
-       if (!info->bitmap && info->offset == offset) {
+       if (!info->bitmap) {
                unlink_free_space(ctl, info);
-               info->offset += bytes;
-               info->bytes -= bytes;
-               ret = link_free_space(ctl, info);
-               WARN_ON(ret);
-               goto out_lock;
-       }
+               if (offset == info->offset) {
+                       u64 to_free = min(bytes, info->bytes);
+
+                       info->bytes -= to_free;
+                       info->offset += to_free;
+                       if (info->bytes) {
+                               ret = link_free_space(ctl, info);
+                               WARN_ON(ret);
+                       } else {
+                               kmem_cache_free(btrfs_free_space_cachep, info);
+                       }
 
-       if (!info->bitmap && info->offset <= offset &&
-           info->offset + info->bytes >= offset + bytes) {
-               u64 old_start = info->offset;
-               /*
-                * we're freeing space in the middle of the info,
-                * this can happen during tree log replay
-                *
-                * first unlink the old info and then
-                * insert it again after the hole we're creating
-                */
-               unlink_free_space(ctl, info);
-               if (offset + bytes < info->offset + info->bytes) {
-                       u64 old_end = info->offset + info->bytes;
+                       offset += to_free;
+                       bytes -= to_free;
+                       goto again;
+               } else {
+                       u64 old_end = info->bytes + info->offset;
 
-                       info->offset = offset + bytes;
-                       info->bytes = old_end - info->offset;
+                       info->bytes = offset - info->offset;
                        ret = link_free_space(ctl, info);
                        WARN_ON(ret);
                        if (ret)
                                goto out_lock;
-               } else {
-                       /* the hole we're creating ends at the end
-                        * of the info struct, just free the info
-                        */
-                       kmem_cache_free(btrfs_free_space_cachep, info);
-               }
-               spin_unlock(&ctl->tree_lock);
 
-               /* step two, insert a new info struct to cover
-                * anything before the hole
-                */
-               ret = btrfs_add_free_space(block_group, old_start,
-                                          offset - old_start);
-               WARN_ON(ret); /* -ENOMEM */
-               goto out;
+                       /* Not enough bytes in this entry to satisfy us */
+                       if (old_end < offset + bytes) {
+                               bytes -= old_end - offset;
+                               offset = old_end;
+                               goto again;
+                       } else if (old_end == offset + bytes) {
+                               /* all done */
+                               goto out_lock;
+                       }
+                       spin_unlock(&ctl->tree_lock);
+
+                       ret = btrfs_add_free_space(block_group, offset + bytes,
+                                                  old_end - (offset + bytes));
+                       WARN_ON(ret);
+                       goto out;
+               }
        }
 
        ret = remove_from_bitmap(ctl, info, &offset, &bytes);