btrfs: convert to using bdi_setup_and_register()
[safe/jmp/linux-2.6] / fs / btrfs / disk-io.c
index 1bb54d6..feca041 100644 (file)
  * Boston, MA 021110-1307, USA.
  */
 
-#include <linux/version.h>
 #include <linux/fs.h>
 #include <linux/blkdev.h>
 #include <linux/scatterlist.h>
 #include <linux/swap.h>
 #include <linux/radix-tree.h>
 #include <linux/writeback.h>
-#include <linux/buffer_head.h> // for block_sync_page
+#include <linux/buffer_head.h>
 #include <linux/workqueue.h>
 #include <linux/kthread.h>
-# include <linux/freezer.h>
-#include "crc32c.h"
+#include <linux/freezer.h>
+#include <linux/crc32c.h>
+#include <linux/slab.h>
+#include "compat.h"
 #include "ctree.h"
 #include "disk-io.h"
 #include "transaction.h"
 #include "print-tree.h"
 #include "async-thread.h"
 #include "locking.h"
-#include "ref-cache.h"
 #include "tree-log.h"
-
-#if 0
-static int check_tree_block(struct btrfs_root *root, struct extent_buffer *buf)
-{
-       if (extent_buffer_blocknr(buf) != btrfs_header_blocknr(buf)) {
-               printk(KERN_CRIT "buf blocknr(buf) is %llu, header is %llu\n",
-                      (unsigned long long)extent_buffer_blocknr(buf),
-                      (unsigned long long)btrfs_header_blocknr(buf));
-               return 1;
-       }
-       return 0;
-}
-#endif
+#include "free-space-cache.h"
 
 static struct extent_io_ops btree_extent_io_ops;
 static void end_workqueue_fn(struct btrfs_work *work);
+static void free_fs_root(struct btrfs_root *root);
 
 /*
  * end_io_wq structs are used to do processing in task context when an IO is
@@ -88,27 +77,61 @@ struct async_submit_bio {
        struct btrfs_work work;
 };
 
+/* These are used to set the lockdep class on the extent buffer locks.
+ * The class is set by the readpage_end_io_hook after the buffer has
+ * passed csum validation but before the pages are unlocked.
+ *
+ * The lockdep class is also set by btrfs_init_new_buffer on freshly
+ * allocated blocks.
+ *
+ * The class is based on the level in the tree block, which allows lockdep
+ * to know that lower nodes nest inside the locks of higher nodes.
+ *
+ * We also add a check to make sure the highest level of the tree is
+ * the same as our lockdep setup here.  If BTRFS_MAX_LEVEL changes, this
+ * code needs update as well.
+ */
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+# if BTRFS_MAX_LEVEL != 8
+#  error
+# endif
+static struct lock_class_key btrfs_eb_class[BTRFS_MAX_LEVEL + 1];
+static const char *btrfs_eb_name[BTRFS_MAX_LEVEL + 1] = {
+       /* leaf */
+       "btrfs-extent-00",
+       "btrfs-extent-01",
+       "btrfs-extent-02",
+       "btrfs-extent-03",
+       "btrfs-extent-04",
+       "btrfs-extent-05",
+       "btrfs-extent-06",
+       "btrfs-extent-07",
+       /* highest possible level */
+       "btrfs-extent-08",
+};
+#endif
+
 /*
  * extents on the btree inode are pretty simple, there's one extent
  * that covers the entire device
  */
-struct extent_map *btree_get_extent(struct inode *inode, struct page *page,
-                                   size_t page_offset, u64 start, u64 len,
-                                   int create)
+static struct extent_map *btree_get_extent(struct inode *inode,
+               struct page *page, size_t page_offset, u64 start, u64 len,
+               int create)
 {
        struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
        struct extent_map *em;
        int ret;
 
-       spin_lock(&em_tree->lock);
+       read_lock(&em_tree->lock);
        em = lookup_extent_mapping(em_tree, start, len);
        if (em) {
                em->bdev =
                        BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
-               spin_unlock(&em_tree->lock);
+               read_unlock(&em_tree->lock);
                goto out;
        }
-       spin_unlock(&em_tree->lock);
+       read_unlock(&em_tree->lock);
 
        em = alloc_extent_map(GFP_NOFS);
        if (!em) {
@@ -121,36 +144,26 @@ struct extent_map *btree_get_extent(struct inode *inode, struct page *page,
        em->block_start = 0;
        em->bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
 
-       spin_lock(&em_tree->lock);
+       write_lock(&em_tree->lock);
        ret = add_extent_mapping(em_tree, em);
        if (ret == -EEXIST) {
                u64 failed_start = em->start;
                u64 failed_len = em->len;
 
-               printk("failed to insert %Lu %Lu -> %Lu into tree\n",
-                      em->start, em->len, em->block_start);
                free_extent_map(em);
                em = lookup_extent_mapping(em_tree, start, len);
                if (em) {
-                       printk("after failing, found %Lu %Lu %Lu\n",
-                              em->start, em->len, em->block_start);
                        ret = 0;
                } else {
                        em = lookup_extent_mapping(em_tree, failed_start,
                                                   failed_len);
-                       if (em) {
-                               printk("double failure lookup gives us "
-                                      "%Lu %Lu -> %Lu\n", em->start,
-                                      em->len, em->block_start);
-                               free_extent_map(em);
-                       }
                        ret = -EIO;
                }
        } else if (ret) {
                free_extent_map(em);
                em = NULL;
        }
-       spin_unlock(&em_tree->lock);
+       write_unlock(&em_tree->lock);
 
        if (ret)
                em = ERR_PTR(ret);
@@ -160,7 +173,7 @@ out:
 
 u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len)
 {
-       return btrfs_crc32c(seed, data, len);
+       return crc32c(seed, data, len);
 }
 
 void btrfs_csum_final(u32 crc, char *result)
@@ -175,7 +188,9 @@ void btrfs_csum_final(u32 crc, char *result)
 static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
                           int verify)
 {
-       char result[BTRFS_CRC32_SIZE];
+       u16 csum_size =
+               btrfs_super_csum_size(&root->fs_info->super_copy);
+       char *result = NULL;
        unsigned long len;
        unsigned long cur_len;
        unsigned long offset = BTRFS_CSUM_SIZE;
@@ -185,17 +200,15 @@ static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
        unsigned long map_len;
        int err;
        u32 crc = ~(u32)0;
+       unsigned long inline_result;
 
        len = buf->len - offset;
-       while(len > 0) {
+       while (len > 0) {
                err = map_private_extent_buffer(buf, offset, 32,
                                        &map_token, &kaddr,
                                        &map_start, &map_len, KM_USER0);
-               if (err) {
-                       printk("failed to map extent buffer! %lu\n",
-                              offset);
+               if (err)
                        return 1;
-               }
                cur_len = min(len, map_len - (offset - map_start));
                crc = btrfs_csum_data(root, kaddr + offset - map_start,
                                      crc, cur_len);
@@ -203,25 +216,40 @@ static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
                offset += cur_len;
                unmap_extent_buffer(buf, map_token, KM_USER0);
        }
+       if (csum_size > sizeof(inline_result)) {
+               result = kzalloc(csum_size * sizeof(char), GFP_NOFS);
+               if (!result)
+                       return 1;
+       } else {
+               result = (char *)&inline_result;
+       }
+
        btrfs_csum_final(crc, result);
 
        if (verify) {
-               /* FIXME, this is not good */
-               if (memcmp_extent_buffer(buf, result, 0, BTRFS_CRC32_SIZE)) {
+               if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
                        u32 val;
                        u32 found = 0;
-                       memcpy(&found, result, BTRFS_CRC32_SIZE);
-
-                       read_extent_buffer(buf, &val, 0, BTRFS_CRC32_SIZE);
-                       printk("btrfs: %s checksum verify failed on %llu "
-                              "wanted %X found %X level %d\n",
-                              root->fs_info->sb->s_id,
-                              buf->start, val, found, btrfs_header_level(buf));
+                       memcpy(&found, result, csum_size);
+
+                       read_extent_buffer(buf, &val, 0, csum_size);
+                       if (printk_ratelimit()) {
+                               printk(KERN_INFO "btrfs: %s checksum verify "
+                                      "failed on %llu wanted %X found %X "
+                                      "level %d\n",
+                                      root->fs_info->sb->s_id,
+                                      (unsigned long long)buf->start, val, found,
+                                      btrfs_header_level(buf));
+                       }
+                       if (result != (char *)&inline_result)
+                               kfree(result);
                        return 1;
                }
        } else {
-               write_extent_buffer(buf, result, 0, BTRFS_CRC32_SIZE);
+               write_extent_buffer(buf, result, 0, csum_size);
        }
+       if (result != (char *)&inline_result)
+               kfree(result);
        return 0;
 }
 
@@ -234,26 +262,31 @@ static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
 static int verify_parent_transid(struct extent_io_tree *io_tree,
                                 struct extent_buffer *eb, u64 parent_transid)
 {
+       struct extent_state *cached_state = NULL;
        int ret;
 
        if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
                return 0;
 
-       lock_extent(io_tree, eb->start, eb->start + eb->len - 1, GFP_NOFS);
-       if (extent_buffer_uptodate(io_tree, eb) &&
+       lock_extent_bits(io_tree, eb->start, eb->start + eb->len - 1,
+                        0, &cached_state, GFP_NOFS);
+       if (extent_buffer_uptodate(io_tree, eb, cached_state) &&
            btrfs_header_generation(eb) == parent_transid) {
                ret = 0;
                goto out;
        }
-       printk("parent transid verify failed on %llu wanted %llu found %llu\n",
-              (unsigned long long)eb->start,
-              (unsigned long long)parent_transid,
-              (unsigned long long)btrfs_header_generation(eb));
+       if (printk_ratelimit()) {
+               printk("parent transid verify failed on %llu wanted %llu "
+                      "found %llu\n",
+                      (unsigned long long)eb->start,
+                      (unsigned long long)parent_transid,
+                      (unsigned long long)btrfs_header_generation(eb));
+       }
        ret = 1;
-       clear_extent_buffer_uptodate(io_tree, eb);
+       clear_extent_buffer_uptodate(io_tree, eb, &cached_state);
 out:
-       unlock_extent(io_tree, eb->start, eb->start + eb->len - 1,
-                     GFP_NOFS);
+       unlock_extent_cached(io_tree, eb->start, eb->start + eb->len - 1,
+                            &cached_state, GFP_NOFS);
        return ret;
 }
 
@@ -277,7 +310,7 @@ static int btree_read_extent_buffer_pages(struct btrfs_root *root,
                if (!ret &&
                    !verify_parent_transid(io_tree, eb, parent_transid))
                        return ret;
-printk("read extent buffer pages failed with ret %d mirror no %d\n", ret, mirror_num);
+
                num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
                                              eb->start, eb->len);
                if (num_copies == 1)
@@ -291,10 +324,11 @@ printk("read extent buffer pages failed with ret %d mirror no %d\n", ret, mirror
 }
 
 /*
- * checksum a dirty tree block before IO.  This has extra checks to make
- * sure we only fill in the checksum field in the first page of a multi-page block
+ * checksum a dirty tree block before IO.  This has extra checks to make sure
+ * we only fill in the checksum field in the first page of a multi-page block
  */
-int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
+
+static int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
 {
        struct extent_io_tree *tree;
        u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
@@ -311,28 +345,22 @@ int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
        if (!page->private)
                goto out;
        len = page->private >> 2;
-       if (len == 0) {
-               WARN_ON(1);
-       }
+       WARN_ON(len == 0);
+
        eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
        ret = btree_read_extent_buffer_pages(root, eb, start + PAGE_CACHE_SIZE,
                                             btrfs_header_generation(eb));
        BUG_ON(ret);
        found_start = btrfs_header_bytenr(eb);
        if (found_start != start) {
-               printk("warning: eb start incorrect %Lu buffer %Lu len %lu\n",
-                      start, found_start, len);
                WARN_ON(1);
                goto err;
        }
        if (eb->first_page != page) {
-               printk("bad first page %lu %lu\n", eb->first_page->index,
-                      page->index);
                WARN_ON(1);
                goto err;
        }
        if (!PageUptodate(page)) {
-               printk("csum not up to date page %lu\n", page->index);
                WARN_ON(1);
                goto err;
        }
@@ -345,7 +373,35 @@ out:
        return 0;
 }
 
-int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
+static int check_tree_block_fsid(struct btrfs_root *root,
+                                struct extent_buffer *eb)
+{
+       struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
+       u8 fsid[BTRFS_UUID_SIZE];
+       int ret = 1;
+
+       read_extent_buffer(eb, fsid, (unsigned long)btrfs_header_fsid(eb),
+                          BTRFS_FSID_SIZE);
+       while (fs_devices) {
+               if (!memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE)) {
+                       ret = 0;
+                       break;
+               }
+               fs_devices = fs_devices->seed;
+       }
+       return ret;
+}
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+void btrfs_set_buffer_lockdep_class(struct extent_buffer *eb, int level)
+{
+       lockdep_set_class_and_name(&eb->lock,
+                          &btrfs_eb_class[level],
+                          btrfs_eb_name[level]);
+}
+#endif
+
+static int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
                               struct extent_state *state)
 {
        struct extent_io_tree *tree;
@@ -361,36 +417,42 @@ int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
                goto out;
        if (!page->private)
                goto out;
+
        len = page->private >> 2;
-       if (len == 0) {
-               WARN_ON(1);
-       }
+       WARN_ON(len == 0);
+
        eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
 
        found_start = btrfs_header_bytenr(eb);
        if (found_start != start) {
-               printk("bad tree block start %llu %llu\n",
-                      (unsigned long long)found_start,
-                      (unsigned long long)eb->start);
+               if (printk_ratelimit()) {
+                       printk(KERN_INFO "btrfs bad tree block start "
+                              "%llu %llu\n",
+                              (unsigned long long)found_start,
+                              (unsigned long long)eb->start);
+               }
                ret = -EIO;
                goto err;
        }
        if (eb->first_page != page) {
-               printk("bad first page %lu %lu\n", eb->first_page->index,
-                      page->index);
+               printk(KERN_INFO "btrfs bad first page %lu %lu\n",
+                      eb->first_page->index, page->index);
                WARN_ON(1);
                ret = -EIO;
                goto err;
        }
-       if (memcmp_extent_buffer(eb, root->fs_info->fsid,
-                                (unsigned long)btrfs_header_fsid(eb),
-                                BTRFS_FSID_SIZE)) {
-               printk("bad fsid on block %Lu\n", eb->start);
+       if (check_tree_block_fsid(root, eb)) {
+               if (printk_ratelimit()) {
+                       printk(KERN_INFO "btrfs bad fsid on block %llu\n",
+                              (unsigned long long)eb->start);
+               }
                ret = -EIO;
                goto err;
        }
        found_level = btrfs_header_level(eb);
 
+       btrfs_set_buffer_lockdep_class(eb, found_level);
+
        ret = csum_tree_block(root, eb, 1);
        if (ret)
                ret = -EIO;
@@ -412,11 +474,22 @@ static void end_workqueue_bio(struct bio *bio, int err)
        end_io_wq->error = err;
        end_io_wq->work.func = end_workqueue_fn;
        end_io_wq->work.flags = 0;
-       if (bio->bi_rw & (1 << BIO_RW))
-               btrfs_queue_worker(&fs_info->endio_write_workers,
-                                  &end_io_wq->work);
-       else
-               btrfs_queue_worker(&fs_info->endio_workers, &end_io_wq->work);
+
+       if (bio->bi_rw & (1 << BIO_RW)) {
+               if (end_io_wq->metadata)
+                       btrfs_queue_worker(&fs_info->endio_meta_write_workers,
+                                          &end_io_wq->work);
+               else
+                       btrfs_queue_worker(&fs_info->endio_write_workers,
+                                          &end_io_wq->work);
+       } else {
+               if (end_io_wq->metadata)
+                       btrfs_queue_worker(&fs_info->endio_meta_workers,
+                                          &end_io_wq->work);
+               else
+                       btrfs_queue_worker(&fs_info->endio_workers,
+                                          &end_io_wq->work);
+       }
 }
 
 int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
@@ -501,7 +574,6 @@ int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
                        extent_submit_bio_hook_t *submit_bio_done)
 {
        struct async_submit_bio *async;
-       int limit = btrfs_async_submit_limit(fs_info);
 
        async = kmalloc(sizeof(*async), GFP_NOFS);
        if (!async)
@@ -521,26 +593,14 @@ int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
        async->work.flags = 0;
        async->bio_flags = bio_flags;
 
-       while(atomic_read(&fs_info->async_submit_draining) &&
-             atomic_read(&fs_info->nr_async_submits)) {
-               wait_event(fs_info->async_submit_wait,
-                          (atomic_read(&fs_info->nr_async_submits) == 0));
-       }
-
        atomic_inc(&fs_info->nr_async_submits);
-       btrfs_queue_worker(&fs_info->workers, &async->work);
 
-       if (atomic_read(&fs_info->nr_async_submits) > limit) {
-               wait_event_timeout(fs_info->async_submit_wait,
-                          (atomic_read(&fs_info->nr_async_submits) < limit),
-                          HZ/10);
+       if (rw & (1 << BIO_RW_SYNCIO))
+               btrfs_set_work_high_prio(&async->work);
 
-               wait_event_timeout(fs_info->async_submit_wait,
-                          (atomic_read(&fs_info->nr_async_bios) < limit),
-                          HZ/10);
-       }
+       btrfs_queue_worker(&fs_info->workers, &async->work);
 
-       while(atomic_read(&fs_info->async_submit_draining) &&
+       while (atomic_read(&fs_info->async_submit_draining) &&
              atomic_read(&fs_info->nr_async_submits)) {
                wait_event(fs_info->async_submit_wait,
                           (atomic_read(&fs_info->nr_async_submits) == 0));
@@ -556,7 +616,7 @@ static int btree_csum_one_bio(struct bio *bio)
        struct btrfs_root *root;
 
        WARN_ON(bio->bi_vcnt <= 0);
-       while(bio_index < bio->bi_vcnt) {
+       while (bio_index < bio->bi_vcnt) {
                root = BTRFS_I(bvec->bv_page->mapping->host)->root;
                csum_dirty_buffer(root, bvec->bv_page);
                bio_index++;
@@ -590,23 +650,25 @@ static int __btree_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
 static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
                                 int mirror_num, unsigned long bio_flags)
 {
-       /*
-        * kthread helpers are used to submit writes so that checksumming
-        * can happen in parallel across all CPUs
-        */
+       int ret;
+
+       ret = btrfs_bio_wq_end_io(BTRFS_I(inode)->root->fs_info,
+                                         bio, 1);
+       BUG_ON(ret);
+
        if (!(rw & (1 << BIO_RW))) {
-               int ret;
                /*
                 * called for a read, do the setup so that checksum validation
                 * can happen in the async kernel threads
                 */
-               ret = btrfs_bio_wq_end_io(BTRFS_I(inode)->root->fs_info,
-                                         bio, 1);
-               BUG_ON(ret);
-
                return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio,
-                                    mirror_num, 1);
+                                    mirror_num, 0);
        }
+
+       /*
+        * kthread helpers are used to submit writes so that checksumming
+        * can happen in parallel across all CPUs
+        */
        return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
                                   inode, rw, bio, mirror_num, 0,
                                   __btree_submit_bio_start,
@@ -616,14 +678,31 @@ static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
 static int btree_writepage(struct page *page, struct writeback_control *wbc)
 {
        struct extent_io_tree *tree;
+       struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
+       struct extent_buffer *eb;
+       int was_dirty;
+
        tree = &BTRFS_I(page->mapping->host)->io_tree;
+       if (!(current->flags & PF_MEMALLOC)) {
+               return extent_write_full_page(tree, page,
+                                             btree_get_extent, wbc);
+       }
 
-       if (current->flags & PF_MEMALLOC) {
-               redirty_page_for_writepage(wbc, page);
-               unlock_page(page);
-               return 0;
+       redirty_page_for_writepage(wbc, page);
+       eb = btrfs_find_tree_block(root, page_offset(page),
+                                     PAGE_CACHE_SIZE);
+       WARN_ON(!eb);
+
+       was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
+       if (!was_dirty) {
+               spin_lock(&root->fs_info->delalloc_lock);
+               root->fs_info->dirty_metadata_bytes += PAGE_CACHE_SIZE;
+               spin_unlock(&root->fs_info->delalloc_lock);
        }
-       return extent_write_full_page(tree, page, btree_get_extent, wbc);
+       free_extent_buffer(eb);
+
+       unlock_page(page);
+       return 0;
 }
 
 static int btree_writepages(struct address_space *mapping,
@@ -632,23 +711,22 @@ static int btree_writepages(struct address_space *mapping,
        struct extent_io_tree *tree;
        tree = &BTRFS_I(mapping->host)->io_tree;
        if (wbc->sync_mode == WB_SYNC_NONE) {
+               struct btrfs_root *root = BTRFS_I(mapping->host)->root;
                u64 num_dirty;
-               u64 start = 0;
                unsigned long thresh = 32 * 1024 * 1024;
 
                if (wbc->for_kupdate)
                        return 0;
 
-               num_dirty = count_range_bits(tree, &start, (u64)-1,
-                                            thresh, EXTENT_DIRTY);
-               if (num_dirty < thresh) {
+               /* this is a bit racy, but that's ok */
+               num_dirty = root->fs_info->dirty_metadata_bytes;
+               if (num_dirty < thresh)
                        return 0;
-               }
        }
        return extent_writepages(tree, mapping, btree_get_extent, wbc);
 }
 
-int btree_readpage(struct file *file, struct page *page)
+static int btree_readpage(struct file *file, struct page *page)
 {
        struct extent_io_tree *tree;
        tree = &BTRFS_I(page->mapping->host)->io_tree;
@@ -662,15 +740,14 @@ static int btree_releasepage(struct page *page, gfp_t gfp_flags)
        int ret;
 
        if (PageWriteback(page) || PageDirty(page))
-           return 0;
+               return 0;
 
        tree = &BTRFS_I(page->mapping->host)->io_tree;
        map = &BTRFS_I(page->mapping->host)->extent_tree;
 
        ret = try_release_extent_state(map, tree, page, gfp_flags);
-       if (!ret) {
+       if (!ret)
                return 0;
-       }
 
        ret = try_release_extent_buffer(tree, page);
        if (ret == 1) {
@@ -689,36 +766,15 @@ static void btree_invalidatepage(struct page *page, unsigned long offset)
        extent_invalidatepage(tree, page, offset);
        btree_releasepage(page, GFP_NOFS);
        if (PagePrivate(page)) {
-               printk("warning page private not zero on page %Lu\n",
-                      page_offset(page));
+               printk(KERN_WARNING "btrfs warning page private not zero "
+                      "on page %llu\n", (unsigned long long)page_offset(page));
                ClearPagePrivate(page);
                set_page_private(page, 0);
                page_cache_release(page);
        }
 }
 
-#if 0
-static int btree_writepage(struct page *page, struct writeback_control *wbc)
-{
-       struct buffer_head *bh;
-       struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
-       struct buffer_head *head;
-       if (!page_has_buffers(page)) {
-               create_empty_buffers(page, root->fs_info->sb->s_blocksize,
-                                       (1 << BH_Dirty)|(1 << BH_Uptodate));
-       }
-       head = page_buffers(page);
-       bh = head;
-       do {
-               if (buffer_dirty(bh))
-                       csum_tree_block(root, bh, 0);
-               bh = bh->b_this_page;
-       } while (bh != head);
-       return block_write_full_page(page, btree_get_block, wbc);
-}
-#endif
-
-static struct address_space_operations btree_aops = {
+static const struct address_space_operations btree_aops = {
        .readpage       = btree_readpage,
        .writepage      = btree_writepage,
        .writepages     = btree_writepages,
@@ -767,14 +823,14 @@ struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
 
 int btrfs_write_tree_block(struct extent_buffer *buf)
 {
-       return btrfs_fdatawrite_range(buf->first_page->mapping, buf->start,
-                                     buf->start + buf->len - 1, WB_SYNC_ALL);
+       return filemap_fdatawrite_range(buf->first_page->mapping, buf->start,
+                                       buf->start + buf->len - 1);
 }
 
 int btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
 {
-       return btrfs_wait_on_page_writeback_range(buf->first_page->mapping,
-                                 buf->start, buf->start + buf->len -1);
+       return filemap_fdatawait_range(buf->first_page->mapping,
+                                      buf->start, buf->start + buf->len - 1);
 }
 
 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
@@ -793,11 +849,8 @@ struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
 
        ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
 
-       if (ret == 0) {
-               buf->flags |= EXTENT_UPTODATE;
-       } else {
-               WARN_ON(1);
-       }
+       if (ret == 0)
+               set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
        return buf;
 
 }
@@ -808,7 +861,19 @@ int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
        struct inode *btree_inode = root->fs_info->btree_inode;
        if (btrfs_header_generation(buf) ==
            root->fs_info->running_transaction->transid) {
-               WARN_ON(!btrfs_tree_locked(buf));
+               btrfs_assert_tree_locked(buf);
+
+               if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)) {
+                       spin_lock(&root->fs_info->delalloc_lock);
+                       if (root->fs_info->dirty_metadata_bytes >= buf->len)
+                               root->fs_info->dirty_metadata_bytes -= buf->len;
+                       else
+                               WARN_ON(1);
+                       spin_unlock(&root->fs_info->delalloc_lock);
+               }
+
+               /* ugh, clear_extent_buffer_dirty needs to lock the page */
+               btrfs_set_lock_blocking(buf);
                clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
                                          buf);
        }
@@ -821,37 +886,44 @@ static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
                        u64 objectid)
 {
        root->node = NULL;
-       root->inode = NULL;
        root->commit_root = NULL;
-       root->ref_tree = NULL;
        root->sectorsize = sectorsize;
        root->nodesize = nodesize;
        root->leafsize = leafsize;
        root->stripesize = stripesize;
        root->ref_cows = 0;
        root->track_dirty = 0;
+       root->in_radix = 0;
+       root->clean_orphans = 0;
 
        root->fs_info = fs_info;
        root->objectid = objectid;
        root->last_trans = 0;
-       root->highest_inode = 0;
-       root->last_inode_alloc = 0;
+       root->highest_objectid = 0;
        root->name = NULL;
        root->in_sysfs = 0;
+       root->inode_tree = RB_ROOT;
 
        INIT_LIST_HEAD(&root->dirty_list);
        INIT_LIST_HEAD(&root->orphan_list);
-       INIT_LIST_HEAD(&root->dead_list);
+       INIT_LIST_HEAD(&root->root_list);
        spin_lock_init(&root->node_lock);
        spin_lock_init(&root->list_lock);
+       spin_lock_init(&root->inode_lock);
        mutex_init(&root->objectid_mutex);
        mutex_init(&root->log_mutex);
+       init_waitqueue_head(&root->log_writer_wait);
+       init_waitqueue_head(&root->log_commit_wait[0]);
+       init_waitqueue_head(&root->log_commit_wait[1]);
+       atomic_set(&root->log_commit[0], 0);
+       atomic_set(&root->log_commit[1], 0);
+       atomic_set(&root->log_writers, 0);
+       root->log_batch = 0;
+       root->log_transid = 0;
+       root->last_log_commit = 0;
        extent_io_tree_init(&root->dirty_log_pages,
                             fs_info->btree_inode->i_mapping, GFP_NOFS);
 
-       btrfs_leaf_ref_tree_init(&root->ref_tree_struct);
-       root->ref_tree = &root->ref_tree_struct;
-
        memset(&root->root_key, 0, sizeof(root->root_key));
        memset(&root->root_item, 0, sizeof(root->root_item));
        memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
@@ -859,8 +931,13 @@ static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
        root->defrag_trans_start = fs_info->generation;
        init_completion(&root->kobj_unregister);
        root->defrag_running = 0;
-       root->defrag_level = 0;
        root->root_key.objectid = objectid;
+       root->anon_super.s_root = NULL;
+       root->anon_super.s_dev = 0;
+       INIT_LIST_HEAD(&root->anon_super.s_list);
+       INIT_LIST_HEAD(&root->anon_super.s_instances);
+       init_rwsem(&root->anon_super.s_umount);
+
        return 0;
 }
 
@@ -878,6 +955,8 @@ static int find_and_setup_root(struct btrfs_root *tree_root,
                     root, fs_info, objectid);
        ret = btrfs_find_last_root(tree_root, objectid,
                                   &root->root_item, &root->root_key);
+       if (ret > 0)
+               return -ENOENT;
        BUG_ON(ret);
 
        generation = btrfs_root_generation(&root->root_item);
@@ -885,6 +964,7 @@ static int find_and_setup_root(struct btrfs_root *tree_root,
        root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
                                     blocksize, generation);
        BUG_ON(!root->node);
+       root->commit_root = btrfs_root_node(root);
        return 0;
 }
 
@@ -900,14 +980,14 @@ int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans,
        if (!log_root_tree)
                return 0;
 
-       while(1) {
+       while (1) {
                ret = find_first_extent_bit(&log_root_tree->dirty_log_pages,
-                                   0, &start, &end, EXTENT_DIRTY);
+                               0, &start, &end, EXTENT_DIRTY | EXTENT_NEW);
                if (ret)
                        break;
 
-               clear_extent_dirty(&log_root_tree->dirty_log_pages,
-                                  start, end, GFP_NOFS);
+               clear_extent_bits(&log_root_tree->dirty_log_pages, start, end,
+                                 EXTENT_DIRTY | EXTENT_NEW, GFP_NOFS);
        }
        eb = fs_info->log_root_tree->node;
 
@@ -924,15 +1004,16 @@ int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans,
        return 0;
 }
 
-int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
-                            struct btrfs_fs_info *fs_info)
+static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
+                                        struct btrfs_fs_info *fs_info)
 {
        struct btrfs_root *root;
        struct btrfs_root *tree_root = fs_info->tree_root;
+       struct extent_buffer *leaf;
 
        root = kzalloc(sizeof(*root), GFP_NOFS);
        if (!root)
-               return -ENOMEM;
+               return ERR_PTR(-ENOMEM);
 
        __setup_root(tree_root->nodesize, tree_root->leafsize,
                     tree_root->sectorsize, tree_root->stripesize,
@@ -941,24 +1022,75 @@ int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
        root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
        root->root_key.type = BTRFS_ROOT_ITEM_KEY;
        root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
+       /*
+        * log trees do not get reference counted because they go away
+        * before a real commit is actually done.  They do store pointers
+        * to file data extents, and those reference counts still get
+        * updated (along with back refs to the log tree).
+        */
        root->ref_cows = 0;
 
-       root->node = btrfs_alloc_free_block(trans, root, root->leafsize,
-                                           0, BTRFS_TREE_LOG_OBJECTID,
-                                           trans->transid, 0, 0, 0);
+       leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 0,
+                                     BTRFS_TREE_LOG_OBJECTID, NULL, 0, 0, 0);
+       if (IS_ERR(leaf)) {
+               kfree(root);
+               return ERR_CAST(leaf);
+       }
 
-       btrfs_set_header_nritems(root->node, 0);
-       btrfs_set_header_level(root->node, 0);
-       btrfs_set_header_bytenr(root->node, root->node->start);
-       btrfs_set_header_generation(root->node, trans->transid);
-       btrfs_set_header_owner(root->node, BTRFS_TREE_LOG_OBJECTID);
+       memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
+       btrfs_set_header_bytenr(leaf, leaf->start);
+       btrfs_set_header_generation(leaf, trans->transid);
+       btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
+       btrfs_set_header_owner(leaf, BTRFS_TREE_LOG_OBJECTID);
+       root->node = leaf;
 
        write_extent_buffer(root->node, root->fs_info->fsid,
                            (unsigned long)btrfs_header_fsid(root->node),
                            BTRFS_FSID_SIZE);
        btrfs_mark_buffer_dirty(root->node);
        btrfs_tree_unlock(root->node);
-       fs_info->log_root_tree = root;
+       return root;
+}
+
+int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
+                            struct btrfs_fs_info *fs_info)
+{
+       struct btrfs_root *log_root;
+
+       log_root = alloc_log_tree(trans, fs_info);
+       if (IS_ERR(log_root))
+               return PTR_ERR(log_root);
+       WARN_ON(fs_info->log_root_tree);
+       fs_info->log_root_tree = log_root;
+       return 0;
+}
+
+int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
+                      struct btrfs_root *root)
+{
+       struct btrfs_root *log_root;
+       struct btrfs_inode_item *inode_item;
+
+       log_root = alloc_log_tree(trans, root->fs_info);
+       if (IS_ERR(log_root))
+               return PTR_ERR(log_root);
+
+       log_root->last_trans = trans->transid;
+       log_root->root_key.offset = root->root_key.objectid;
+
+       inode_item = &log_root->root_item.inode;
+       inode_item->generation = cpu_to_le64(1);
+       inode_item->size = cpu_to_le64(3);
+       inode_item->nlink = cpu_to_le32(1);
+       inode_item->nbytes = cpu_to_le64(root->leafsize);
+       inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
+
+       btrfs_set_root_node(&log_root->root_item, log_root->node);
+
+       WARN_ON(root->log_root);
+       root->log_root = log_root;
+       root->log_transid = 0;
+       root->last_log_commit = 0;
        return 0;
 }
 
@@ -969,7 +1101,6 @@ struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
        struct btrfs_fs_info *fs_info = tree_root->fs_info;
        struct btrfs_path *path;
        struct extent_buffer *l;
-       u64 highest_inode;
        u64 generation;
        u32 blocksize;
        int ret = 0;
@@ -984,7 +1115,7 @@ struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
                        kfree(root);
                        return ERR_PTR(ret);
                }
-               goto insert;
+               goto out;
        }
 
        __setup_root(tree_root->nodesize, tree_root->leafsize,
@@ -994,38 +1125,30 @@ struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
        path = btrfs_alloc_path();
        BUG_ON(!path);
        ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
-       if (ret != 0) {
-               if (ret > 0)
-                       ret = -ENOENT;
-               goto out;
+       if (ret == 0) {
+               l = path->nodes[0];
+               read_extent_buffer(l, &root->root_item,
+                               btrfs_item_ptr_offset(l, path->slots[0]),
+                               sizeof(root->root_item));
+               memcpy(&root->root_key, location, sizeof(*location));
        }
-       l = path->nodes[0];
-       read_extent_buffer(l, &root->root_item,
-              btrfs_item_ptr_offset(l, path->slots[0]),
-              sizeof(root->root_item));
-       memcpy(&root->root_key, location, sizeof(*location));
-       ret = 0;
-out:
-       btrfs_release_path(root, path);
        btrfs_free_path(path);
        if (ret) {
-               kfree(root);
+               if (ret > 0)
+                       ret = -ENOENT;
                return ERR_PTR(ret);
        }
+
        generation = btrfs_root_generation(&root->root_item);
        blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
        root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
                                     blocksize, generation);
+       root->commit_root = btrfs_root_node(root);
        BUG_ON(!root->node);
-insert:
-       if (location->objectid != BTRFS_TREE_LOG_OBJECTID) {
+out:
+       if (location->objectid != BTRFS_TREE_LOG_OBJECTID)
                root->ref_cows = 1;
-               ret = btrfs_find_highest_inode(root, &highest_inode);
-               if (ret == 0) {
-                       root->highest_inode = highest_inode;
-                       root->last_inode_alloc = highest_inode;
-               }
-       }
+
        return root;
 }
 
@@ -1058,34 +1181,66 @@ struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
                return fs_info->chunk_root;
        if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
                return fs_info->dev_root;
-
+       if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
+               return fs_info->csum_root;
+again:
+       spin_lock(&fs_info->fs_roots_radix_lock);
        root = radix_tree_lookup(&fs_info->fs_roots_radix,
                                 (unsigned long)location->objectid);
+       spin_unlock(&fs_info->fs_roots_radix_lock);
        if (root)
                return root;
 
+       ret = btrfs_find_orphan_item(fs_info->tree_root, location->objectid);
+       if (ret == 0)
+               ret = -ENOENT;
+       if (ret < 0)
+               return ERR_PTR(ret);
+
        root = btrfs_read_fs_root_no_radix(fs_info->tree_root, location);
        if (IS_ERR(root))
                return root;
+
+       WARN_ON(btrfs_root_refs(&root->root_item) == 0);
+       set_anon_super(&root->anon_super, NULL);
+
+       ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
+       if (ret)
+               goto fail;
+
+       spin_lock(&fs_info->fs_roots_radix_lock);
        ret = radix_tree_insert(&fs_info->fs_roots_radix,
                                (unsigned long)root->root_key.objectid,
                                root);
+       if (ret == 0) {
+               root->in_radix = 1;
+               root->clean_orphans = 1;
+       }
+       spin_unlock(&fs_info->fs_roots_radix_lock);
+       radix_tree_preload_end();
        if (ret) {
-               free_extent_buffer(root->node);
-               kfree(root);
-               return ERR_PTR(ret);
+               if (ret == -EEXIST) {
+                       free_fs_root(root);
+                       goto again;
+               }
+               goto fail;
        }
-       ret = btrfs_find_dead_roots(fs_info->tree_root,
-                                   root->root_key.objectid, root);
-       BUG_ON(ret);
 
+       ret = btrfs_find_dead_roots(fs_info->tree_root,
+                                   root->root_key.objectid);
+       WARN_ON(ret);
        return root;
+fail:
+       free_fs_root(root);
+       return ERR_PTR(ret);
 }
 
 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
                                      struct btrfs_key *location,
                                      const char *name, int namelen)
 {
+       return btrfs_read_fs_root_no_name(fs_info, location);
+#if 0
        struct btrfs_root *root;
        int ret;
 
@@ -1112,40 +1267,17 @@ struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
        }
        root->in_sysfs = 1;
        return root;
-}
-#if 0
-static int add_hasher(struct btrfs_fs_info *info, char *type) {
-       struct btrfs_hasher *hasher;
-
-       hasher = kmalloc(sizeof(*hasher), GFP_NOFS);
-       if (!hasher)
-               return -ENOMEM;
-       hasher->hash_tfm = crypto_alloc_hash(type, 0, CRYPTO_ALG_ASYNC);
-       if (!hasher->hash_tfm) {
-               kfree(hasher);
-               return -EINVAL;
-       }
-       spin_lock(&info->hash_lock);
-       list_add(&hasher->list, &info->hashers);
-       spin_unlock(&info->hash_lock);
-       return 0;
-}
 #endif
+}
 
 static int btrfs_congested_fn(void *congested_data, int bdi_bits)
 {
        struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
        int ret = 0;
-       struct list_head *cur;
        struct btrfs_device *device;
        struct backing_dev_info *bdi;
 
-       if ((bdi_bits & (1 << BDI_write_congested)) &&
-           btrfs_congested_async(info, 0))
-               return 1;
-
-       list_for_each(cur, &info->fs_devices->devices) {
-               device = list_entry(cur, struct btrfs_device, dev_list);
+       list_for_each_entry(device, &info->fs_devices->devices, dev_list) {
                if (!device->bdev)
                        continue;
                bdi = blk_get_backing_dev_info(device->bdev);
@@ -1163,21 +1295,21 @@ static int btrfs_congested_fn(void *congested_data, int bdi_bits)
  */
 static void __unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
 {
-       struct list_head *cur;
        struct btrfs_device *device;
        struct btrfs_fs_info *info;
 
        info = (struct btrfs_fs_info *)bdi->unplug_io_data;
-       list_for_each(cur, &info->fs_devices->devices) {
-               device = list_entry(cur, struct btrfs_device, dev_list);
+       list_for_each_entry(device, &info->fs_devices->devices, dev_list) {
+               if (!device->bdev)
+                       continue;
+
                bdi = blk_get_backing_dev_info(device->bdev);
-               if (bdi->unplug_io_fn) {
+               if (bdi->unplug_io_fn)
                        bdi->unplug_io_fn(bdi, page);
-               }
        }
 }
 
-void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
+static void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
 {
        struct inode *inode;
        struct extent_map_tree *em_tree;
@@ -1186,7 +1318,7 @@ void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
        u64 offset;
 
        /* the generic O_DIRECT read code does this */
-       if (!page) {
+       if (1 || !page) {
                __unplug_io_fn(bdi, page);
                return;
        }
@@ -1214,9 +1346,9 @@ void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
        offset = page_offset(page);
 
        em_tree = &BTRFS_I(inode)->extent_tree;
-       spin_lock(&em_tree->lock);
+       read_lock(&em_tree->lock);
        em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
-       spin_unlock(&em_tree->lock);
+       read_unlock(&em_tree->lock);
        if (!em) {
                __unplug_io_fn(bdi, page);
                return;
@@ -1233,12 +1365,20 @@ void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
        free_extent_map(em);
 }
 
+/*
+ * If this fails, caller must call bdi_destroy() to get rid of the
+ * bdi again.
+ */
 static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
 {
-       bdi_init(bdi);
+       int err;
+
+       bdi->capabilities = BDI_CAP_MAP_COPY;
+       err = bdi_setup_and_register(bdi, "btrfs", BDI_CAP_MAP_COPY);
+       if (err)
+               return err;
+
        bdi->ra_pages   = default_backing_dev_info.ra_pages;
-       bdi->state              = 0;
-       bdi->capabilities       = default_backing_dev_info.capabilities;
        bdi->unplug_io_fn       = btrfs_unplug_io_fn;
        bdi->unplug_io_data     = info;
        bdi->congested_fn       = btrfs_congested_fn;
@@ -1280,8 +1420,6 @@ static int bio_ready_for_csum(struct bio *bio)
 
        ret = extent_range_uptodate(io_tree, start + length,
                                    start + buf_len - 1);
-       if (ret == 1)
-               return ret;
        return ret;
 }
 
@@ -1300,13 +1438,14 @@ static void end_workqueue_fn(struct btrfs_work *work)
        bio = end_io_wq->bio;
        fs_info = end_io_wq->info;
 
-       /* metadata bios are special because the whole tree block must
+       /* metadata bio reads are special because the whole tree block must
         * be checksummed at once.  This makes sure the entire block is in
         * ram and up to date before trying to verify things.  For
         * blocksize <= pagesize, it is basically a noop
         */
-       if (end_io_wq->metadata && !bio_ready_for_csum(bio)) {
-               btrfs_queue_worker(&fs_info->endio_workers,
+       if (!(bio->bi_rw & (1 << BIO_RW)) && end_io_wq->metadata &&
+           !bio_ready_for_csum(bio)) {
+               btrfs_queue_worker(&fs_info->endio_meta_workers,
                                   &end_io_wq->work);
                return;
        }
@@ -1327,9 +1466,13 @@ static int cleaner_kthread(void *arg)
                        break;
 
                vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
-               mutex_lock(&root->fs_info->cleaner_mutex);
-               btrfs_clean_old_snapshots(root);
-               mutex_unlock(&root->fs_info->cleaner_mutex);
+
+               if (!(root->fs_info->sb->s_flags & MS_RDONLY) &&
+                   mutex_trylock(&root->fs_info->cleaner_mutex)) {
+                       btrfs_run_delayed_iputs(root);
+                       btrfs_clean_old_snapshots(root);
+                       mutex_unlock(&root->fs_info->cleaner_mutex);
+               }
 
                if (freezing(current)) {
                        refrigerator();
@@ -1363,11 +1506,6 @@ static int transaction_kthread(void *arg)
                vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
                mutex_lock(&root->fs_info->transaction_kthread_mutex);
 
-               if (root->fs_info->total_ref_cache_size > 20 * 1024 * 1024) {
-                       printk("btrfs: total reference cache size %Lu\n",
-                               root->fs_info->total_ref_cache_size);
-               }
-
                mutex_lock(&root->fs_info->trans_mutex);
                cur = root->fs_info->running_transaction;
                if (!cur) {
@@ -1384,6 +1522,7 @@ static int transaction_kthread(void *arg)
                mutex_unlock(&root->fs_info->trans_mutex);
                trans = btrfs_start_transaction(root, 1);
                ret = btrfs_commit_transaction(trans, root);
+
 sleep:
                wake_up_process(root->fs_info->cleaner_kthread);
                mutex_unlock(&root->fs_info->transaction_kthread_mutex);
@@ -1411,9 +1550,13 @@ struct btrfs_root *open_ctree(struct super_block *sb,
        u32 blocksize;
        u32 stripesize;
        u64 generation;
+       u64 features;
+       struct btrfs_key location;
        struct buffer_head *bh;
        struct btrfs_root *extent_root = kzalloc(sizeof(struct btrfs_root),
                                                 GFP_NOFS);
+       struct btrfs_root *csum_root = kzalloc(sizeof(struct btrfs_root),
+                                                GFP_NOFS);
        struct btrfs_root *tree_root = kzalloc(sizeof(struct btrfs_root),
                                               GFP_NOFS);
        struct btrfs_fs_info *fs_info = kzalloc(sizeof(*fs_info),
@@ -1430,23 +1573,47 @@ struct btrfs_root *open_ctree(struct super_block *sb,
        struct btrfs_super_block *disk_super;
 
        if (!extent_root || !tree_root || !fs_info ||
-           !chunk_root || !dev_root) {
+           !chunk_root || !dev_root || !csum_root) {
                err = -ENOMEM;
                goto fail;
        }
-       INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_NOFS);
+
+       ret = init_srcu_struct(&fs_info->subvol_srcu);
+       if (ret) {
+               err = ret;
+               goto fail;
+       }
+
+       ret = setup_bdi(fs_info, &fs_info->bdi);
+       if (ret) {
+               err = ret;
+               goto fail_srcu;
+       }
+
+       fs_info->btree_inode = new_inode(sb);
+       if (!fs_info->btree_inode) {
+               err = -ENOMEM;
+               goto fail_bdi;
+       }
+
+       INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
        INIT_LIST_HEAD(&fs_info->trans_list);
        INIT_LIST_HEAD(&fs_info->dead_roots);
+       INIT_LIST_HEAD(&fs_info->delayed_iputs);
        INIT_LIST_HEAD(&fs_info->hashers);
        INIT_LIST_HEAD(&fs_info->delalloc_inodes);
-       spin_lock_init(&fs_info->hash_lock);
+       INIT_LIST_HEAD(&fs_info->ordered_operations);
+       INIT_LIST_HEAD(&fs_info->caching_block_groups);
        spin_lock_init(&fs_info->delalloc_lock);
        spin_lock_init(&fs_info->new_trans_lock);
        spin_lock_init(&fs_info->ref_cache_lock);
+       spin_lock_init(&fs_info->fs_roots_radix_lock);
+       spin_lock_init(&fs_info->delayed_iput_lock);
 
        init_completion(&fs_info->kobj_unregister);
        fs_info->tree_root = tree_root;
        fs_info->extent_root = extent_root;
+       fs_info->csum_root = csum_root;
        fs_info->chunk_root = chunk_root;
        fs_info->dev_root = dev_root;
        fs_info->fs_devices = fs_devices;
@@ -1457,24 +1624,22 @@ struct btrfs_root *open_ctree(struct super_block *sb,
        atomic_set(&fs_info->async_delalloc_pages, 0);
        atomic_set(&fs_info->async_submit_draining, 0);
        atomic_set(&fs_info->nr_async_bios, 0);
-       atomic_set(&fs_info->throttles, 0);
-       atomic_set(&fs_info->throttle_gen, 0);
        fs_info->sb = sb;
-       fs_info->max_extent = (u64)-1;
        fs_info->max_inline = 8192 * 1024;
-       setup_bdi(fs_info, &fs_info->bdi);
-       fs_info->btree_inode = new_inode(sb);
-       fs_info->btree_inode->i_ino = 1;
-       fs_info->btree_inode->i_nlink = 1;
+       fs_info->metadata_ratio = 0;
 
-       fs_info->thread_pool_size = min(num_online_cpus() + 2, 8);
+       fs_info->thread_pool_size = min_t(unsigned long,
+                                         num_online_cpus() + 2, 8);
 
        INIT_LIST_HEAD(&fs_info->ordered_extents);
        spin_lock_init(&fs_info->ordered_extent_lock);
 
        sb->s_blocksize = 4096;
        sb->s_blocksize_bits = blksize_bits(4096);
+       sb->s_bdi = &fs_info->bdi;
 
+       fs_info->btree_inode->i_ino = BTRFS_BTREE_INODE_OBJECTID;
+       fs_info->btree_inode->i_nlink = 1;
        /*
         * we set the i_size on the btree inode to the max possible int.
         * the real end of the address space is determined by all of
@@ -1484,6 +1649,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
        fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
        fs_info->btree_inode->i_mapping->backing_dev_info = &fs_info->bdi;
 
+       RB_CLEAR_NODE(&BTRFS_I(fs_info->btree_inode)->rb_node);
        extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
                             fs_info->btree_inode->i_mapping,
                             GFP_NOFS);
@@ -1492,88 +1658,110 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 
        BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
 
+       BTRFS_I(fs_info->btree_inode)->root = tree_root;
+       memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
+              sizeof(struct btrfs_key));
+       BTRFS_I(fs_info->btree_inode)->dummy_inode = 1;
+       insert_inode_hash(fs_info->btree_inode);
+
        spin_lock_init(&fs_info->block_group_cache_lock);
-       fs_info->block_group_cache_tree.rb_node = NULL;
+       fs_info->block_group_cache_tree = RB_ROOT;
 
-       extent_io_tree_init(&fs_info->pinned_extents,
+       extent_io_tree_init(&fs_info->freed_extents[0],
                             fs_info->btree_inode->i_mapping, GFP_NOFS);
-       extent_io_tree_init(&fs_info->pending_del,
-                            fs_info->btree_inode->i_mapping, GFP_NOFS);
-       extent_io_tree_init(&fs_info->extent_ins,
+       extent_io_tree_init(&fs_info->freed_extents[1],
                             fs_info->btree_inode->i_mapping, GFP_NOFS);
+       fs_info->pinned_extents = &fs_info->freed_extents[0];
        fs_info->do_barriers = 1;
 
-       INIT_LIST_HEAD(&fs_info->dead_reloc_roots);
-       btrfs_leaf_ref_tree_init(&fs_info->reloc_ref_tree);
-       btrfs_leaf_ref_tree_init(&fs_info->shared_ref_tree);
-
-       BTRFS_I(fs_info->btree_inode)->root = tree_root;
-       memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
-              sizeof(struct btrfs_key));
-       insert_inode_hash(fs_info->btree_inode);
 
        mutex_init(&fs_info->trans_mutex);
+       mutex_init(&fs_info->ordered_operations_mutex);
        mutex_init(&fs_info->tree_log_mutex);
-       mutex_init(&fs_info->drop_mutex);
-       mutex_init(&fs_info->extent_ins_mutex);
-       mutex_init(&fs_info->pinned_mutex);
        mutex_init(&fs_info->chunk_mutex);
        mutex_init(&fs_info->transaction_kthread_mutex);
        mutex_init(&fs_info->cleaner_mutex);
        mutex_init(&fs_info->volume_mutex);
-       mutex_init(&fs_info->tree_reloc_mutex);
+       init_rwsem(&fs_info->extent_commit_sem);
+       init_rwsem(&fs_info->cleanup_work_sem);
+       init_rwsem(&fs_info->subvol_sem);
+
+       btrfs_init_free_cluster(&fs_info->meta_alloc_cluster);
+       btrfs_init_free_cluster(&fs_info->data_alloc_cluster);
+
        init_waitqueue_head(&fs_info->transaction_throttle);
        init_waitqueue_head(&fs_info->transaction_wait);
        init_waitqueue_head(&fs_info->async_submit_wait);
-       init_waitqueue_head(&fs_info->tree_log_wait);
-       atomic_set(&fs_info->tree_log_commit, 0);
-       atomic_set(&fs_info->tree_log_writers, 0);
-       fs_info->tree_log_transid = 0;
 
-#if 0
-       ret = add_hasher(fs_info, "crc32c");
-       if (ret) {
-               printk("btrfs: failed hash setup, modprobe cryptomgr?\n");
-               err = -ENOMEM;
-               goto fail_iput;
-       }
-#endif
        __setup_root(4096, 4096, 4096, 4096, tree_root,
                     fs_info, BTRFS_ROOT_TREE_OBJECTID);
 
 
-       bh = __bread(fs_devices->latest_bdev,
-                    BTRFS_SUPER_INFO_OFFSET / 4096, 4096);
+       bh = btrfs_read_dev_super(fs_devices->latest_bdev);
        if (!bh)
                goto fail_iput;
 
        memcpy(&fs_info->super_copy, bh->b_data, sizeof(fs_info->super_copy));
+       memcpy(&fs_info->super_for_commit, &fs_info->super_copy,
+              sizeof(fs_info->super_for_commit));
        brelse(bh);
 
        memcpy(fs_info->fsid, fs_info->super_copy.fsid, BTRFS_FSID_SIZE);
 
        disk_super = &fs_info->super_copy;
        if (!btrfs_super_root(disk_super))
-               goto fail_sb_buffer;
+               goto fail_iput;
 
-       err = btrfs_parse_options(tree_root, options);
-       if (err)
-               goto fail_sb_buffer;
+       ret = btrfs_parse_options(tree_root, options);
+       if (ret) {
+               err = ret;
+               goto fail_iput;
+       }
+
+       features = btrfs_super_incompat_flags(disk_super) &
+               ~BTRFS_FEATURE_INCOMPAT_SUPP;
+       if (features) {
+               printk(KERN_ERR "BTRFS: couldn't mount because of "
+                      "unsupported optional features (%Lx).\n",
+                      (unsigned long long)features);
+               err = -EINVAL;
+               goto fail_iput;
+       }
+
+       features = btrfs_super_incompat_flags(disk_super);
+       if (!(features & BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF)) {
+               features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
+               btrfs_set_super_incompat_flags(disk_super, features);
+       }
+
+       features = btrfs_super_compat_ro_flags(disk_super) &
+               ~BTRFS_FEATURE_COMPAT_RO_SUPP;
+       if (!(sb->s_flags & MS_RDONLY) && features) {
+               printk(KERN_ERR "BTRFS: couldn't mount RDWR because of "
+                      "unsupported option features (%Lx).\n",
+                      (unsigned long long)features);
+               err = -EINVAL;
+               goto fail_iput;
+       }
+
+       btrfs_init_workers(&fs_info->generic_worker,
+                          "genwork", 1, NULL);
 
-       /*
-        * we need to start all the end_io workers up front because the
-        * queue work function gets called at interrupt time, and so it
-        * cannot dynamically grow.
-        */
        btrfs_init_workers(&fs_info->workers, "worker",
-                          fs_info->thread_pool_size);
+                          fs_info->thread_pool_size,
+                          &fs_info->generic_worker);
 
        btrfs_init_workers(&fs_info->delalloc_workers, "delalloc",
-                          fs_info->thread_pool_size);
+                          fs_info->thread_pool_size,
+                          &fs_info->generic_worker);
 
        btrfs_init_workers(&fs_info->submit_workers, "submit",
                           min_t(u64, fs_devices->num_devices,
-                          fs_info->thread_pool_size));
+                          fs_info->thread_pool_size),
+                          &fs_info->generic_worker);
+       btrfs_init_workers(&fs_info->enospc_workers, "enospc",
+                          fs_info->thread_pool_size,
+                          &fs_info->generic_worker);
 
        /* a higher idle thresh on the submit workers makes it much more
         * likely that bios will be send down in a sane order to the
@@ -1587,38 +1775,41 @@ struct btrfs_root *open_ctree(struct super_block *sb,
        fs_info->delalloc_workers.idle_thresh = 2;
        fs_info->delalloc_workers.ordered = 1;
 
-       btrfs_init_workers(&fs_info->fixup_workers, "fixup", 1);
+       btrfs_init_workers(&fs_info->fixup_workers, "fixup", 1,
+                          &fs_info->generic_worker);
        btrfs_init_workers(&fs_info->endio_workers, "endio",
-                          fs_info->thread_pool_size);
+                          fs_info->thread_pool_size,
+                          &fs_info->generic_worker);
+       btrfs_init_workers(&fs_info->endio_meta_workers, "endio-meta",
+                          fs_info->thread_pool_size,
+                          &fs_info->generic_worker);
+       btrfs_init_workers(&fs_info->endio_meta_write_workers,
+                          "endio-meta-write", fs_info->thread_pool_size,
+                          &fs_info->generic_worker);
        btrfs_init_workers(&fs_info->endio_write_workers, "endio-write",
-                          fs_info->thread_pool_size);
+                          fs_info->thread_pool_size,
+                          &fs_info->generic_worker);
 
        /*
         * endios are largely parallel and should have a very
         * low idle thresh
         */
        fs_info->endio_workers.idle_thresh = 4;
-       fs_info->endio_write_workers.idle_thresh = 64;
+       fs_info->endio_meta_workers.idle_thresh = 4;
+
+       fs_info->endio_write_workers.idle_thresh = 2;
+       fs_info->endio_meta_write_workers.idle_thresh = 2;
 
        btrfs_start_workers(&fs_info->workers, 1);
+       btrfs_start_workers(&fs_info->generic_worker, 1);
        btrfs_start_workers(&fs_info->submit_workers, 1);
        btrfs_start_workers(&fs_info->delalloc_workers, 1);
        btrfs_start_workers(&fs_info->fixup_workers, 1);
-       btrfs_start_workers(&fs_info->endio_workers, fs_info->thread_pool_size);
-       btrfs_start_workers(&fs_info->endio_write_workers,
-                           fs_info->thread_pool_size);
-
-       err = -EINVAL;
-       if (btrfs_super_num_devices(disk_super) > fs_devices->open_devices) {
-               printk("Btrfs: wanted %llu devices, but found %llu\n",
-                      (unsigned long long)btrfs_super_num_devices(disk_super),
-                      (unsigned long long)fs_devices->open_devices);
-               if (btrfs_test_opt(tree_root, DEGRADED))
-                       printk("continuing in degraded mode\n");
-               else {
-                       goto fail_sb_buffer;
-               }
-       }
+       btrfs_start_workers(&fs_info->endio_workers, 1);
+       btrfs_start_workers(&fs_info->endio_meta_workers, 1);
+       btrfs_start_workers(&fs_info->endio_meta_write_workers, 1);
+       btrfs_start_workers(&fs_info->endio_write_workers, 1);
+       btrfs_start_workers(&fs_info->enospc_workers, 1);
 
        fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
        fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages,
@@ -1638,7 +1829,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 
        if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
                    sizeof(disk_super->magic))) {
-               printk("btrfs: valid FS not found on %s\n", sb->s_id);
+               printk(KERN_INFO "btrfs: valid FS not found on %s\n", sb->s_id);
                goto fail_sb_buffer;
        }
 
@@ -1646,9 +1837,9 @@ struct btrfs_root *open_ctree(struct super_block *sb,
        ret = btrfs_read_sys_array(tree_root);
        mutex_unlock(&fs_info->chunk_mutex);
        if (ret) {
-               printk("btrfs: failed to read the system array on %s\n",
-                      sb->s_id);
-               goto fail_sys_array;
+               printk(KERN_WARNING "btrfs: failed to read the system "
+                      "array on %s\n", sb->s_id);
+               goto fail_sb_buffer;
        }
 
        blocksize = btrfs_level_size(tree_root,
@@ -1662,15 +1853,26 @@ struct btrfs_root *open_ctree(struct super_block *sb,
                                           btrfs_super_chunk_root(disk_super),
                                           blocksize, generation);
        BUG_ON(!chunk_root->node);
+       if (!test_bit(EXTENT_BUFFER_UPTODATE, &chunk_root->node->bflags)) {
+               printk(KERN_WARNING "btrfs: failed to read chunk root on %s\n",
+                      sb->s_id);
+               goto fail_chunk_root;
+       }
+       btrfs_set_root_node(&chunk_root->root_item, chunk_root->node);
+       chunk_root->commit_root = btrfs_root_node(chunk_root);
 
        read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
-                (unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node),
-                BTRFS_UUID_SIZE);
+          (unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node),
+          BTRFS_UUID_SIZE);
 
        mutex_lock(&fs_info->chunk_mutex);
        ret = btrfs_read_chunk_tree(chunk_root);
        mutex_unlock(&fs_info->chunk_mutex);
-       BUG_ON(ret);
+       if (ret) {
+               printk(KERN_WARNING "btrfs: failed to read chunk tree on %s\n",
+                      sb->s_id);
+               goto fail_chunk_root;
+       }
 
        btrfs_close_extra_devices(fs_devices);
 
@@ -1682,8 +1884,14 @@ struct btrfs_root *open_ctree(struct super_block *sb,
                                          btrfs_super_root(disk_super),
                                          blocksize, generation);
        if (!tree_root->node)
-               goto fail_sb_buffer;
-
+               goto fail_chunk_root;
+       if (!test_bit(EXTENT_BUFFER_UPTODATE, &tree_root->node->bflags)) {
+               printk(KERN_WARNING "btrfs: failed to read tree root on %s\n",
+                      sb->s_id);
+               goto fail_tree_root;
+       }
+       btrfs_set_root_node(&tree_root->root_item, tree_root->node);
+       tree_root->commit_root = btrfs_root_node(tree_root);
 
        ret = find_and_setup_root(tree_root, fs_info,
                                  BTRFS_EXTENT_TREE_OBJECTID, extent_root);
@@ -1693,32 +1901,56 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 
        ret = find_and_setup_root(tree_root, fs_info,
                                  BTRFS_DEV_TREE_OBJECTID, dev_root);
+       if (ret)
+               goto fail_extent_root;
        dev_root->track_dirty = 1;
 
+       ret = find_and_setup_root(tree_root, fs_info,
+                                 BTRFS_CSUM_TREE_OBJECTID, csum_root);
        if (ret)
-               goto fail_extent_root;
+               goto fail_dev_root;
 
-       btrfs_read_block_groups(extent_root);
+       csum_root->track_dirty = 1;
 
-       fs_info->generation = btrfs_super_generation(disk_super) + 1;
+       ret = btrfs_read_block_groups(extent_root);
+       if (ret) {
+               printk(KERN_ERR "Failed to read block groups: %d\n", ret);
+               goto fail_block_groups;
+       }
+
+       fs_info->generation = generation;
+       fs_info->last_trans_committed = generation;
        fs_info->data_alloc_profile = (u64)-1;
        fs_info->metadata_alloc_profile = (u64)-1;
        fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
        fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
                                               "btrfs-cleaner");
-       if (!fs_info->cleaner_kthread)
-               goto fail_extent_root;
+       if (IS_ERR(fs_info->cleaner_kthread))
+               goto fail_block_groups;
 
        fs_info->transaction_kthread = kthread_run(transaction_kthread,
                                                   tree_root,
                                                   "btrfs-transaction");
-       if (!fs_info->transaction_kthread)
+       if (IS_ERR(fs_info->transaction_kthread))
                goto fail_cleaner;
 
+       if (!btrfs_test_opt(tree_root, SSD) &&
+           !btrfs_test_opt(tree_root, NOSSD) &&
+           !fs_info->fs_devices->rotating) {
+               printk(KERN_INFO "Btrfs detected SSD devices, enabling SSD "
+                      "mode\n");
+               btrfs_set_opt(fs_info->mount_opt, SSD);
+       }
+
        if (btrfs_super_log_root(disk_super) != 0) {
-               u32 blocksize;
                u64 bytenr = btrfs_super_log_root(disk_super);
 
+               if (fs_devices->rw_devices == 0) {
+                       printk(KERN_WARNING "Btrfs log replay required "
+                              "on RO media\n");
+                       err = -EIO;
+                       goto fail_trans_kthread;
+               }
                blocksize =
                     btrfs_level_size(tree_root,
                                      btrfs_super_log_root_level(disk_super));
@@ -1734,40 +1966,98 @@ struct btrfs_root *open_ctree(struct super_block *sb,
                                                      generation + 1);
                ret = btrfs_recover_log_trees(log_tree_root);
                BUG_ON(ret);
+
+               if (sb->s_flags & MS_RDONLY) {
+                       ret =  btrfs_commit_super(tree_root);
+                       BUG_ON(ret);
+               }
        }
-       fs_info->last_trans_committed = btrfs_super_generation(disk_super);
 
-       ret = btrfs_cleanup_reloc_trees(tree_root);
+       ret = btrfs_find_orphan_roots(tree_root);
        BUG_ON(ret);
 
+       if (!(sb->s_flags & MS_RDONLY)) {
+               ret = btrfs_recover_relocation(tree_root);
+               if (ret < 0) {
+                       printk(KERN_WARNING
+                              "btrfs: failed to recover relocation\n");
+                       err = -EINVAL;
+                       goto fail_trans_kthread;
+               }
+       }
+
+       location.objectid = BTRFS_FS_TREE_OBJECTID;
+       location.type = BTRFS_ROOT_ITEM_KEY;
+       location.offset = (u64)-1;
+
+       fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location);
+       if (!fs_info->fs_root)
+               goto fail_trans_kthread;
+
+       if (!(sb->s_flags & MS_RDONLY)) {
+               down_read(&fs_info->cleanup_work_sem);
+               btrfs_orphan_cleanup(fs_info->fs_root);
+               up_read(&fs_info->cleanup_work_sem);
+       }
+
        return tree_root;
 
+fail_trans_kthread:
+       kthread_stop(fs_info->transaction_kthread);
 fail_cleaner:
        kthread_stop(fs_info->cleaner_kthread);
+
+       /*
+        * make sure we're done with the btree inode before we stop our
+        * kthreads
+        */
+       filemap_write_and_wait(fs_info->btree_inode->i_mapping);
+       invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
+
+fail_block_groups:
+       btrfs_free_block_groups(fs_info);
+       free_extent_buffer(csum_root->node);
+       free_extent_buffer(csum_root->commit_root);
+fail_dev_root:
+       free_extent_buffer(dev_root->node);
+       free_extent_buffer(dev_root->commit_root);
 fail_extent_root:
        free_extent_buffer(extent_root->node);
+       free_extent_buffer(extent_root->commit_root);
 fail_tree_root:
        free_extent_buffer(tree_root->node);
-fail_sys_array:
+       free_extent_buffer(tree_root->commit_root);
+fail_chunk_root:
+       free_extent_buffer(chunk_root->node);
+       free_extent_buffer(chunk_root->commit_root);
 fail_sb_buffer:
+       btrfs_stop_workers(&fs_info->generic_worker);
        btrfs_stop_workers(&fs_info->fixup_workers);
        btrfs_stop_workers(&fs_info->delalloc_workers);
        btrfs_stop_workers(&fs_info->workers);
        btrfs_stop_workers(&fs_info->endio_workers);
+       btrfs_stop_workers(&fs_info->endio_meta_workers);
+       btrfs_stop_workers(&fs_info->endio_meta_write_workers);
        btrfs_stop_workers(&fs_info->endio_write_workers);
        btrfs_stop_workers(&fs_info->submit_workers);
+       btrfs_stop_workers(&fs_info->enospc_workers);
 fail_iput:
+       invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
        iput(fs_info->btree_inode);
-fail:
+
        btrfs_close_devices(fs_info->fs_devices);
        btrfs_mapping_tree_free(&fs_info->mapping_tree);
-
+fail_bdi:
+       bdi_destroy(&fs_info->bdi);
+fail_srcu:
+       cleanup_srcu_struct(&fs_info->subvol_srcu);
+fail:
        kfree(extent_root);
        kfree(tree_root);
-       bdi_destroy(&fs_info->bdi);
        kfree(fs_info);
        kfree(chunk_root);
        kfree(dev_root);
+       kfree(csum_root);
        return ERR_PTR(err);
 }
 
@@ -1792,19 +2082,161 @@ static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
        put_bh(bh);
 }
 
-int write_all_supers(struct btrfs_root *root)
+struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
+{
+       struct buffer_head *bh;
+       struct buffer_head *latest = NULL;
+       struct btrfs_super_block *super;
+       int i;
+       u64 transid = 0;
+       u64 bytenr;
+
+       /* we would like to check all the supers, but that would make
+        * a btrfs mount succeed after a mkfs from a different FS.
+        * So, we need to add a special mount option to scan for
+        * later supers, using BTRFS_SUPER_MIRROR_MAX instead
+        */
+       for (i = 0; i < 1; i++) {
+               bytenr = btrfs_sb_offset(i);
+               if (bytenr + 4096 >= i_size_read(bdev->bd_inode))
+                       break;
+               bh = __bread(bdev, bytenr / 4096, 4096);
+               if (!bh)
+                       continue;
+
+               super = (struct btrfs_super_block *)bh->b_data;
+               if (btrfs_super_bytenr(super) != bytenr ||
+                   strncmp((char *)(&super->magic), BTRFS_MAGIC,
+                           sizeof(super->magic))) {
+                       brelse(bh);
+                       continue;
+               }
+
+               if (!latest || btrfs_super_generation(super) > transid) {
+                       brelse(latest);
+                       latest = bh;
+                       transid = btrfs_super_generation(super);
+               } else {
+                       brelse(bh);
+               }
+       }
+       return latest;
+}
+
+/*
+ * this should be called twice, once with wait == 0 and
+ * once with wait == 1.  When wait == 0 is done, all the buffer heads
+ * we write are pinned.
+ *
+ * They are released when wait == 1 is done.
+ * max_mirrors must be the same for both runs, and it indicates how
+ * many supers on this one device should be written.
+ *
+ * max_mirrors == 0 means to write them all.
+ */
+static int write_dev_supers(struct btrfs_device *device,
+                           struct btrfs_super_block *sb,
+                           int do_barriers, int wait, int max_mirrors)
+{
+       struct buffer_head *bh;
+       int i;
+       int ret;
+       int errors = 0;
+       u32 crc;
+       u64 bytenr;
+       int last_barrier = 0;
+
+       if (max_mirrors == 0)
+               max_mirrors = BTRFS_SUPER_MIRROR_MAX;
+
+       /* make sure only the last submit_bh does a barrier */
+       if (do_barriers) {
+               for (i = 0; i < max_mirrors; i++) {
+                       bytenr = btrfs_sb_offset(i);
+                       if (bytenr + BTRFS_SUPER_INFO_SIZE >=
+                           device->total_bytes)
+                               break;
+                       last_barrier = i;
+               }
+       }
+
+       for (i = 0; i < max_mirrors; i++) {
+               bytenr = btrfs_sb_offset(i);
+               if (bytenr + BTRFS_SUPER_INFO_SIZE >= device->total_bytes)
+                       break;
+
+               if (wait) {
+                       bh = __find_get_block(device->bdev, bytenr / 4096,
+                                             BTRFS_SUPER_INFO_SIZE);
+                       BUG_ON(!bh);
+                       wait_on_buffer(bh);
+                       if (!buffer_uptodate(bh))
+                               errors++;
+
+                       /* drop our reference */
+                       brelse(bh);
+
+                       /* drop the reference from the wait == 0 run */
+                       brelse(bh);
+                       continue;
+               } else {
+                       btrfs_set_super_bytenr(sb, bytenr);
+
+                       crc = ~(u32)0;
+                       crc = btrfs_csum_data(NULL, (char *)sb +
+                                             BTRFS_CSUM_SIZE, crc,
+                                             BTRFS_SUPER_INFO_SIZE -
+                                             BTRFS_CSUM_SIZE);
+                       btrfs_csum_final(crc, sb->csum);
+
+                       /*
+                        * one reference for us, and we leave it for the
+                        * caller
+                        */
+                       bh = __getblk(device->bdev, bytenr / 4096,
+                                     BTRFS_SUPER_INFO_SIZE);
+                       memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE);
+
+                       /* one reference for submit_bh */
+                       get_bh(bh);
+
+                       set_buffer_uptodate(bh);
+                       lock_buffer(bh);
+                       bh->b_end_io = btrfs_end_buffer_write_sync;
+               }
+
+               if (i == last_barrier && do_barriers && device->barriers) {
+                       ret = submit_bh(WRITE_BARRIER, bh);
+                       if (ret == -EOPNOTSUPP) {
+                               printk("btrfs: disabling barriers on dev %s\n",
+                                      device->name);
+                               set_buffer_uptodate(bh);
+                               device->barriers = 0;
+                               /* one reference for submit_bh */
+                               get_bh(bh);
+                               lock_buffer(bh);
+                               ret = submit_bh(WRITE_SYNC, bh);
+                       }
+               } else {
+                       ret = submit_bh(WRITE_SYNC, bh);
+               }
+
+               if (ret)
+                       errors++;
+       }
+       return errors < i ? 0 : -1;
+}
+
+int write_all_supers(struct btrfs_root *root, int max_mirrors)
 {
-       struct list_head *cur;
-       struct list_head *head = &root->fs_info->fs_devices->devices;
+       struct list_head *head;
        struct btrfs_device *dev;
        struct btrfs_super_block *sb;
        struct btrfs_dev_item *dev_item;
-       struct buffer_head *bh;
        int ret;
        int do_barriers;
        int max_errors;
        int total_errors = 0;
-       u32 crc;
        u64 flags;
 
        max_errors = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
@@ -1812,15 +2244,18 @@ int write_all_supers(struct btrfs_root *root)
 
        sb = &root->fs_info->super_for_commit;
        dev_item = &sb->dev_item;
-       list_for_each(cur, head) {
-               dev = list_entry(cur, struct btrfs_device, dev_list);
+
+       mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
+       head = &root->fs_info->fs_devices->devices;
+       list_for_each_entry(dev, head, dev_list) {
                if (!dev->bdev) {
                        total_errors++;
                        continue;
                }
-               if (!dev->in_fs_metadata)
+               if (!dev->in_fs_metadata || !dev->writeable)
                        continue;
 
+               btrfs_set_stack_device_generation(dev_item, 0);
                btrfs_set_stack_device_type(dev_item, dev->type);
                btrfs_set_stack_device_id(dev_item, dev->devid);
                btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes);
@@ -1829,121 +2264,98 @@ int write_all_supers(struct btrfs_root *root)
                btrfs_set_stack_device_io_width(dev_item, dev->io_width);
                btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
                memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
+               memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
+
                flags = btrfs_super_flags(sb);
                btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
 
-
-               crc = ~(u32)0;
-               crc = btrfs_csum_data(root, (char *)sb + BTRFS_CSUM_SIZE, crc,
-                                     BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
-               btrfs_csum_final(crc, sb->csum);
-
-               bh = __getblk(dev->bdev, BTRFS_SUPER_INFO_OFFSET / 4096,
-                             BTRFS_SUPER_INFO_SIZE);
-
-               memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE);
-               dev->pending_io = bh;
-
-               get_bh(bh);
-               set_buffer_uptodate(bh);
-               lock_buffer(bh);
-               bh->b_end_io = btrfs_end_buffer_write_sync;
-
-               if (do_barriers && dev->barriers) {
-                       ret = submit_bh(WRITE_BARRIER, bh);
-                       if (ret == -EOPNOTSUPP) {
-                               printk("btrfs: disabling barriers on dev %s\n",
-                                      dev->name);
-                               set_buffer_uptodate(bh);
-                               dev->barriers = 0;
-                               get_bh(bh);
-                               lock_buffer(bh);
-                               ret = submit_bh(WRITE, bh);
-                       }
-               } else {
-                       ret = submit_bh(WRITE, bh);
-               }
+               ret = write_dev_supers(dev, sb, do_barriers, 0, max_mirrors);
                if (ret)
                        total_errors++;
        }
        if (total_errors > max_errors) {
-               printk("btrfs: %d errors while writing supers\n", total_errors);
+               printk(KERN_ERR "btrfs: %d errors while writing supers\n",
+                      total_errors);
                BUG();
        }
-       total_errors = 0;
 
-       list_for_each(cur, head) {
-               dev = list_entry(cur, struct btrfs_device, dev_list);
+       total_errors = 0;
+       list_for_each_entry(dev, head, dev_list) {
                if (!dev->bdev)
                        continue;
-               if (!dev->in_fs_metadata)
+               if (!dev->in_fs_metadata || !dev->writeable)
                        continue;
 
-               BUG_ON(!dev->pending_io);
-               bh = dev->pending_io;
-               wait_on_buffer(bh);
-               if (!buffer_uptodate(dev->pending_io)) {
-                       if (do_barriers && dev->barriers) {
-                               printk("btrfs: disabling barriers on dev %s\n",
-                                      dev->name);
-                               set_buffer_uptodate(bh);
-                               get_bh(bh);
-                               lock_buffer(bh);
-                               dev->barriers = 0;
-                               ret = submit_bh(WRITE, bh);
-                               BUG_ON(ret);
-                               wait_on_buffer(bh);
-                               if (!buffer_uptodate(bh))
-                                       total_errors++;
-                       } else {
-                               total_errors++;
-                       }
-
-               }
-               dev->pending_io = NULL;
-               brelse(bh);
+               ret = write_dev_supers(dev, sb, do_barriers, 1, max_mirrors);
+               if (ret)
+                       total_errors++;
        }
+       mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
        if (total_errors > max_errors) {
-               printk("btrfs: %d errors while writing supers\n", total_errors);
+               printk(KERN_ERR "btrfs: %d errors while writing supers\n",
+                      total_errors);
                BUG();
        }
        return 0;
 }
 
-int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root
-                     *root)
+int write_ctree_super(struct btrfs_trans_handle *trans,
+                     struct btrfs_root *root, int max_mirrors)
 {
        int ret;
 
-       ret = write_all_supers(root);
+       ret = write_all_supers(root, max_mirrors);
        return ret;
 }
 
 int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
 {
+       spin_lock(&fs_info->fs_roots_radix_lock);
        radix_tree_delete(&fs_info->fs_roots_radix,
                          (unsigned long)root->root_key.objectid);
-       if (root->in_sysfs)
-               btrfs_sysfs_del_root(root);
-       if (root->inode)
-               iput(root->inode);
-       if (root->node)
-               free_extent_buffer(root->node);
-       if (root->commit_root)
-               free_extent_buffer(root->commit_root);
-       if (root->name)
-               kfree(root->name);
-       kfree(root);
+       spin_unlock(&fs_info->fs_roots_radix_lock);
+
+       if (btrfs_root_refs(&root->root_item) == 0)
+               synchronize_srcu(&fs_info->subvol_srcu);
+
+       free_fs_root(root);
        return 0;
 }
 
+static void free_fs_root(struct btrfs_root *root)
+{
+       WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree));
+       if (root->anon_super.s_dev) {
+               down_write(&root->anon_super.s_umount);
+               kill_anon_super(&root->anon_super);
+       }
+       free_extent_buffer(root->node);
+       free_extent_buffer(root->commit_root);
+       kfree(root->name);
+       kfree(root);
+}
+
 static int del_fs_roots(struct btrfs_fs_info *fs_info)
 {
        int ret;
        struct btrfs_root *gang[8];
        int i;
 
-       while(1) {
+       while (!list_empty(&fs_info->dead_roots)) {
+               gang[0] = list_entry(fs_info->dead_roots.next,
+                                    struct btrfs_root, root_list);
+               list_del(&gang[0]->root_list);
+
+               if (gang[0]->in_radix) {
+                       btrfs_free_fs_root(fs_info, gang[0]);
+               } else {
+                       free_extent_buffer(gang[0]->node);
+                       free_extent_buffer(gang[0]->commit_root);
+                       kfree(gang[0]);
+               }
+       }
+
+       while (1) {
                ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
                                             (void **)gang, 0,
                                             ARRAY_SIZE(gang));
@@ -1955,85 +2367,125 @@ static int del_fs_roots(struct btrfs_fs_info *fs_info)
        return 0;
 }
 
-int close_ctree(struct btrfs_root *root)
+int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
 {
+       u64 root_objectid = 0;
+       struct btrfs_root *gang[8];
+       int i;
        int ret;
-       struct btrfs_trans_handle *trans;
-       struct btrfs_fs_info *fs_info = root->fs_info;
 
-       fs_info->closing = 1;
-       smp_mb();
+       while (1) {
+               ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
+                                            (void **)gang, root_objectid,
+                                            ARRAY_SIZE(gang));
+               if (!ret)
+                       break;
 
-       kthread_stop(root->fs_info->transaction_kthread);
-       kthread_stop(root->fs_info->cleaner_kthread);
+               root_objectid = gang[ret - 1]->root_key.objectid + 1;
+               for (i = 0; i < ret; i++) {
+                       root_objectid = gang[i]->root_key.objectid;
+                       btrfs_orphan_cleanup(gang[i]);
+               }
+               root_objectid++;
+       }
+       return 0;
+}
 
+int btrfs_commit_super(struct btrfs_root *root)
+{
+       struct btrfs_trans_handle *trans;
+       int ret;
+
+       mutex_lock(&root->fs_info->cleaner_mutex);
+       btrfs_run_delayed_iputs(root);
        btrfs_clean_old_snapshots(root);
+       mutex_unlock(&root->fs_info->cleaner_mutex);
+
+       /* wait until ongoing cleanup work done */
+       down_write(&root->fs_info->cleanup_work_sem);
+       up_write(&root->fs_info->cleanup_work_sem);
+
        trans = btrfs_start_transaction(root, 1);
        ret = btrfs_commit_transaction(trans, root);
-       /* run commit again to  drop the original snapshot */
+       BUG_ON(ret);
+       /* run commit again to drop the original snapshot */
        trans = btrfs_start_transaction(root, 1);
        btrfs_commit_transaction(trans, root);
        ret = btrfs_write_and_wait_transaction(NULL, root);
        BUG_ON(ret);
 
-       write_ctree_super(NULL, root);
+       ret = write_ctree_super(NULL, root, 0);
+       return ret;
+}
+
+int close_ctree(struct btrfs_root *root)
+{
+       struct btrfs_fs_info *fs_info = root->fs_info;
+       int ret;
+
+       fs_info->closing = 1;
+       smp_mb();
+
+       kthread_stop(root->fs_info->transaction_kthread);
+       kthread_stop(root->fs_info->cleaner_kthread);
+
+       if (!(fs_info->sb->s_flags & MS_RDONLY)) {
+               ret =  btrfs_commit_super(root);
+               if (ret)
+                       printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
+       }
+
+       fs_info->closing = 2;
+       smp_mb();
 
        if (fs_info->delalloc_bytes) {
-               printk("btrfs: at unmount delalloc count %Lu\n",
-                      fs_info->delalloc_bytes);
+               printk(KERN_INFO "btrfs: at unmount delalloc count %llu\n",
+                      (unsigned long long)fs_info->delalloc_bytes);
        }
        if (fs_info->total_ref_cache_size) {
-               printk("btrfs: at umount reference cache size %Lu\n",
-                       fs_info->total_ref_cache_size);
+               printk(KERN_INFO "btrfs: at umount reference cache size %llu\n",
+                      (unsigned long long)fs_info->total_ref_cache_size);
        }
 
-       if (fs_info->extent_root->node)
-               free_extent_buffer(fs_info->extent_root->node);
-
-       if (fs_info->tree_root->node)
-               free_extent_buffer(fs_info->tree_root->node);
-
-       if (root->fs_info->chunk_root->node);
-               free_extent_buffer(root->fs_info->chunk_root->node);
-
-       if (root->fs_info->dev_root->node);
-               free_extent_buffer(root->fs_info->dev_root->node);
+       free_extent_buffer(fs_info->extent_root->node);
+       free_extent_buffer(fs_info->extent_root->commit_root);
+       free_extent_buffer(fs_info->tree_root->node);
+       free_extent_buffer(fs_info->tree_root->commit_root);
+       free_extent_buffer(root->fs_info->chunk_root->node);
+       free_extent_buffer(root->fs_info->chunk_root->commit_root);
+       free_extent_buffer(root->fs_info->dev_root->node);
+       free_extent_buffer(root->fs_info->dev_root->commit_root);
+       free_extent_buffer(root->fs_info->csum_root->node);
+       free_extent_buffer(root->fs_info->csum_root->commit_root);
 
        btrfs_free_block_groups(root->fs_info);
-       fs_info->closing = 2;
-       del_fs_roots(fs_info);
 
-       filemap_write_and_wait(fs_info->btree_inode->i_mapping);
+       del_fs_roots(fs_info);
 
-       truncate_inode_pages(fs_info->btree_inode->i_mapping, 0);
+       iput(fs_info->btree_inode);
 
+       btrfs_stop_workers(&fs_info->generic_worker);
        btrfs_stop_workers(&fs_info->fixup_workers);
        btrfs_stop_workers(&fs_info->delalloc_workers);
        btrfs_stop_workers(&fs_info->workers);
        btrfs_stop_workers(&fs_info->endio_workers);
+       btrfs_stop_workers(&fs_info->endio_meta_workers);
+       btrfs_stop_workers(&fs_info->endio_meta_write_workers);
        btrfs_stop_workers(&fs_info->endio_write_workers);
        btrfs_stop_workers(&fs_info->submit_workers);
+       btrfs_stop_workers(&fs_info->enospc_workers);
 
-       iput(fs_info->btree_inode);
-#if 0
-       while(!list_empty(&fs_info->hashers)) {
-               struct btrfs_hasher *hasher;
-               hasher = list_entry(fs_info->hashers.next, struct btrfs_hasher,
-                                   hashers);
-               list_del(&hasher->hashers);
-               crypto_free_hash(&fs_info->hash_tfm);
-               kfree(hasher);
-       }
-#endif
        btrfs_close_devices(fs_info->fs_devices);
        btrfs_mapping_tree_free(&fs_info->mapping_tree);
 
        bdi_destroy(&fs_info->bdi);
+       cleanup_srcu_struct(&fs_info->subvol_srcu);
 
        kfree(fs_info->extent_root);
        kfree(fs_info->tree_root);
        kfree(fs_info->chunk_root);
        kfree(fs_info->dev_root);
+       kfree(fs_info->csum_root);
        return 0;
 }
 
@@ -2042,7 +2494,8 @@ int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid)
        int ret;
        struct inode *btree_inode = buf->first_page->mapping->host;
 
-       ret = extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf);
+       ret = extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf,
+                                    NULL);
        if (!ret)
                return ret;
 
@@ -2063,15 +2516,24 @@ void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
        struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
        u64 transid = btrfs_header_generation(buf);
        struct inode *btree_inode = root->fs_info->btree_inode;
+       int was_dirty;
 
-       WARN_ON(!btrfs_tree_locked(buf));
+       btrfs_assert_tree_locked(buf);
        if (transid != root->fs_info->generation) {
-               printk(KERN_CRIT "transid mismatch buffer %llu, found %Lu running %Lu\n",
+               printk(KERN_CRIT "btrfs transid mismatch buffer %llu, "
+                      "found %llu running %llu\n",
                        (unsigned long long)buf->start,
-                       transid, root->fs_info->generation);
+                       (unsigned long long)transid,
+                       (unsigned long long)root->fs_info->generation);
                WARN_ON(1);
        }
-       set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree, buf);
+       was_dirty = set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
+                                           buf);
+       if (!was_dirty) {
+               spin_lock(&root->fs_info->delalloc_lock);
+               root->fs_info->dirty_metadata_bytes += buf->len;
+               spin_unlock(&root->fs_info->delalloc_lock);
+       }
 }
 
 void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
@@ -2080,17 +2542,14 @@ void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
         * looks as though older kernels can get into trouble with
         * this code, they end up stuck in balance_dirty_pages forever
         */
-       struct extent_io_tree *tree;
        u64 num_dirty;
-       u64 start = 0;
        unsigned long thresh = 32 * 1024 * 1024;
-       tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
 
-       if (current_is_pdflush() || current->flags & PF_MEMALLOC)
+       if (current->flags & PF_MEMALLOC)
                return;
 
-       num_dirty = count_range_bits(tree, &start, (u64)-1,
-                                    thresh, EXTENT_DIRTY);
+       num_dirty = root->fs_info->dirty_metadata_bytes;
+
        if (num_dirty > thresh) {
                balance_dirty_pages_ratelimited_nr(
                                   root->fs_info->btree_inode->i_mapping, 1);
@@ -2103,9 +2562,8 @@ int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
        struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
        int ret;
        ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
-       if (ret == 0) {
-               buf->flags |= EXTENT_UPTODATE;
-       }
+       if (ret == 0)
+               set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
        return ret;
 }
 
@@ -2127,9 +2585,17 @@ int btree_lock_page_hook(struct page *page)
                goto out;
 
        btrfs_tree_lock(eb);
-       spin_lock(&root->fs_info->hash_lock);
        btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
-       spin_unlock(&root->fs_info->hash_lock);
+
+       if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
+               spin_lock(&root->fs_info->delalloc_lock);
+               if (root->fs_info->dirty_metadata_bytes >= eb->len)
+                       root->fs_info->dirty_metadata_bytes -= eb->len;
+               else
+                       WARN_ON(1);
+               spin_unlock(&root->fs_info->delalloc_lock);
+       }
+
        btrfs_tree_unlock(eb);
        free_extent_buffer(eb);
 out: