Merge branch 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6
[safe/jmp/linux-2.6] / fs / btrfs / disk-io.c
index 6f042de..f3b287c 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 <linux/crc32c.h>
+#include <linux/slab.h>
 #include "compat.h"
-#include "crc32c.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
@@ -86,9 +74,48 @@ struct async_submit_bio {
        int rw;
        int mirror_num;
        unsigned long bio_flags;
+       /*
+        * bio_offset is optional, can be used if the pages in the bio
+        * can't tell us where in the file the bio should go
+        */
+       u64 bio_offset;
        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
@@ -101,15 +128,15 @@ static struct extent_map *btree_get_extent(struct inode *inode,
        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) {
@@ -122,36 +149,26 @@ static struct extent_map *btree_get_extent(struct inode *inode,
        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);
@@ -161,7 +178,7 @@ 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)
@@ -191,15 +208,12 @@ static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
        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);
@@ -218,17 +232,20 @@ static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
        btrfs_csum_final(crc, result);
 
        if (verify) {
-               /* FIXME, this is not good */
                if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
                        u32 val;
                        u32 found = 0;
                        memcpy(&found, result, csum_size);
 
                        read_extent_buffer(buf, &val, 0, csum_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));
+                       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;
@@ -250,26 +267,31 @@ 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;
 }
 
@@ -293,7 +315,7 @@ 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)
@@ -307,9 +329,10 @@ 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
  */
+
 static int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
 {
        struct extent_io_tree *tree;
@@ -327,28 +350,22 @@ static 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;
        }
@@ -380,6 +397,15 @@ static int check_tree_block_fsid(struct btrfs_root *root,
        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)
 {
@@ -396,34 +422,42 @@ static 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 (check_tree_block_fsid(root, eb)) {
-               printk("bad fsid on block %Lu\n", eb->start);
+               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;
@@ -447,8 +481,12 @@ static void end_workqueue_bio(struct bio *bio, int err)
        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);
+               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,
@@ -501,7 +539,8 @@ static void run_one_async_start(struct btrfs_work *work)
        async = container_of(work, struct  async_submit_bio, work);
        fs_info = BTRFS_I(async->inode)->root->fs_info;
        async->submit_bio_start(async->inode, async->rw, async->bio,
-                              async->mirror_num, async->bio_flags);
+                              async->mirror_num, async->bio_flags,
+                              async->bio_offset);
 }
 
 static void run_one_async_done(struct btrfs_work *work)
@@ -523,7 +562,8 @@ static void run_one_async_done(struct btrfs_work *work)
                wake_up(&fs_info->async_submit_wait);
 
        async->submit_bio_done(async->inode, async->rw, async->bio,
-                              async->mirror_num, async->bio_flags);
+                              async->mirror_num, async->bio_flags,
+                              async->bio_offset);
 }
 
 static void run_one_async_free(struct btrfs_work *work)
@@ -537,6 +577,7 @@ static void run_one_async_free(struct btrfs_work *work)
 int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
                        int rw, struct bio *bio, int mirror_num,
                        unsigned long bio_flags,
+                       u64 bio_offset,
                        extent_submit_bio_hook_t *submit_bio_start,
                        extent_submit_bio_hook_t *submit_bio_done)
 {
@@ -559,22 +600,16 @@ int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
 
        async->work.flags = 0;
        async->bio_flags = bio_flags;
+       async->bio_offset = bio_offset;
 
        atomic_inc(&fs_info->nr_async_submits);
+
+       if (rw & (1 << BIO_RW_SYNCIO))
+               btrfs_set_work_high_prio(&async->work);
+
        btrfs_queue_worker(&fs_info->workers, &async->work);
-#if 0
-       int limit = btrfs_async_submit_limit(fs_info);
-       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);
 
-               wait_event_timeout(fs_info->async_submit_wait,
-                          (atomic_read(&fs_info->nr_async_bios) < limit),
-                          HZ/10);
-       }
-#endif
-       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));
@@ -590,7 +625,7 @@ 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++;
@@ -601,7 +636,8 @@ static int btree_csum_one_bio(struct bio *bio)
 
 static int __btree_submit_bio_start(struct inode *inode, int rw,
                                    struct bio *bio, int mirror_num,
-                                   unsigned long bio_flags)
+                                   unsigned long bio_flags,
+                                   u64 bio_offset)
 {
        /*
         * when we're called for a write, we're already in the async
@@ -612,7 +648,8 @@ static int __btree_submit_bio_start(struct inode *inode, int rw,
 }
 
 static int __btree_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
-                                int mirror_num, unsigned long bio_flags)
+                                int mirror_num, unsigned long bio_flags,
+                                u64 bio_offset)
 {
        /*
         * when we're called for a write, we're already in the async
@@ -622,27 +659,31 @@ 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)
+                                int mirror_num, unsigned long bio_flags,
+                                u64 bio_offset)
 {
-       /*
-        * 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, 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,
+                                  bio_offset,
                                   __btree_submit_bio_start,
                                   __btree_submit_bio_done);
 }
@@ -650,14 +691,31 @@ 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,
@@ -666,18 +724,17 @@ 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);
 }
@@ -696,15 +753,14 @@ 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) {
@@ -723,36 +779,15 @@ 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,
@@ -801,14 +836,14 @@ 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,
@@ -827,11 +862,8 @@ 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;
 
 }
@@ -842,7 +874,19 @@ 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);
        }
@@ -856,35 +900,47 @@ static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
 {
        root->node = 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->orphan_item_inserted = 0;
+       root->orphan_cleanup_state = 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;
+       root->block_rsv = NULL;
+       root->orphan_block_rsv = NULL;
 
        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->orphan_lock);
+       spin_lock_init(&root->inode_lock);
+       spin_lock_init(&root->accounting_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));
@@ -892,7 +948,6 @@ 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;
@@ -917,6 +972,8 @@ 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);
@@ -924,54 +981,20 @@ 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;
 }
 
-int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans,
-                            struct btrfs_fs_info *fs_info)
-{
-       struct extent_buffer *eb;
-       struct btrfs_root *log_root_tree = fs_info->log_root_tree;
-       u64 start = 0;
-       u64 end = 0;
-       int ret;
-
-       if (!log_root_tree)
-               return 0;
-
-       while(1) {
-               ret = find_first_extent_bit(&log_root_tree->dirty_log_pages,
-                                   0, &start, &end, EXTENT_DIRTY);
-               if (ret)
-                       break;
-
-               clear_extent_dirty(&log_root_tree->dirty_log_pages,
-                                  start, end, GFP_NOFS);
-       }
-       eb = fs_info->log_root_tree->node;
-
-       WARN_ON(btrfs_header_level(eb) != 0);
-       WARN_ON(btrfs_header_nritems(eb) != 0);
-
-       ret = btrfs_free_reserved_extent(fs_info->tree_root,
-                               eb->start, eb->len);
-       BUG_ON(ret);
-
-       free_extent_buffer(eb);
-       kfree(fs_info->log_root_tree);
-       fs_info->log_root_tree = NULL;
-       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,
@@ -980,24 +1003,75 @@ 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;
 }
 
@@ -1008,7 +1082,6 @@ 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;
@@ -1023,7 +1096,7 @@ 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,
@@ -1033,38 +1106,30 @@ 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;
 }
 
@@ -1099,9 +1164,11 @@ struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
                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;
 
@@ -1111,27 +1178,53 @@ struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
 
        set_anon_super(&root->anon_super, NULL);
 
+       if (btrfs_root_refs(&root->root_item) == 0) {
+               ret = -ENOENT;
+               goto fail;
+       }
+
+       ret = btrfs_find_orphan_item(fs_info->tree_root, location->objectid);
+       if (ret < 0)
+               goto fail;
+       if (ret == 0)
+               root->orphan_item_inserted = 1;
+
+       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;
+
+       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 (!(fs_info->sb->s_flags & MS_RDONLY)) {
-               ret = btrfs_find_dead_roots(fs_info->tree_root,
-                                           root->root_key.objectid, root);
-               BUG_ON(ret);
-               btrfs_orphan_cleanup(root);
+               if (ret == -EEXIST) {
+                       free_fs_root(root);
+                       goto again;
+               }
+               goto fail;
        }
+
+       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;
 
@@ -1148,7 +1241,7 @@ struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
                kfree(root);
                return ERR_PTR(ret);
        }
-#if 0
+
        ret = btrfs_sysfs_add_root(root);
        if (ret) {
                free_extent_buffer(root->node);
@@ -1156,43 +1249,19 @@ struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
                kfree(root);
                return ERR_PTR(ret);
        }
-#endif
        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 0
-       if ((bdi_bits & (1 << BDI_write_congested)) &&
-           btrfs_congested_async(info, 0))
-               return 1;
-#endif
-       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);
@@ -1210,20 +1279,17 @@ 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);
-               }
        }
 }
 
@@ -1264,9 +1330,9 @@ static 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;
@@ -1283,12 +1349,20 @@ static 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;
@@ -1330,8 +1404,6 @@ 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;
 }
 
@@ -1350,12 +1422,13 @@ 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)) {
+       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;
@@ -1372,23 +1445,21 @@ static int cleaner_kthread(void *arg)
        struct btrfs_root *root = arg;
 
        do {
-               smp_mb();
-               if (root->fs_info->closing)
-                       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();
                } else {
-                       smp_mb();
-                       if (root->fs_info->closing)
-                               break;
                        set_current_state(TASK_INTERRUPTIBLE);
-                       schedule();
+                       if (!kthread_should_stop())
+                               schedule();
                        __set_current_state(TASK_RUNNING);
                }
        } while (!kthread_should_stop());
@@ -1400,40 +1471,40 @@ static int transaction_kthread(void *arg)
        struct btrfs_root *root = arg;
        struct btrfs_trans_handle *trans;
        struct btrfs_transaction *cur;
+       u64 transid;
        unsigned long now;
        unsigned long delay;
        int ret;
 
        do {
-               smp_mb();
-               if (root->fs_info->closing)
-                       break;
-
                delay = HZ * 30;
                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);
+               spin_lock(&root->fs_info->new_trans_lock);
                cur = root->fs_info->running_transaction;
                if (!cur) {
-                       mutex_unlock(&root->fs_info->trans_mutex);
+                       spin_unlock(&root->fs_info->new_trans_lock);
                        goto sleep;
                }
 
                now = get_seconds();
-               if (now < cur->start_time || now - cur->start_time < 30) {
-                       mutex_unlock(&root->fs_info->trans_mutex);
+               if (!cur->blocked &&
+                   (now < cur->start_time || now - cur->start_time < 30)) {
+                       spin_unlock(&root->fs_info->new_trans_lock);
                        delay = HZ * 5;
                        goto sleep;
                }
-               mutex_unlock(&root->fs_info->trans_mutex);
-               trans = btrfs_start_transaction(root, 1);
-               ret = btrfs_commit_transaction(trans, root);
+               transid = cur->transid;
+               spin_unlock(&root->fs_info->new_trans_lock);
+
+               trans = btrfs_join_transaction(root, 1);
+               if (transid == trans->transid) {
+                       ret = btrfs_commit_transaction(trans, root);
+                       BUG_ON(ret);
+               } else {
+                       btrfs_end_transaction(trans, root);
+               }
 sleep:
                wake_up_process(root->fs_info->cleaner_kthread);
                mutex_unlock(&root->fs_info->transaction_kthread_mutex);
@@ -1441,10 +1512,10 @@ sleep:
                if (freezing(current)) {
                        refrigerator();
                } else {
-                       if (root->fs_info->closing)
-                               break;
                        set_current_state(TASK_INTERRUPTIBLE);
-                       schedule_timeout(delay);
+                       if (!kthread_should_stop() &&
+                           !btrfs_transaction_blocked(root->fs_info))
+                               schedule_timeout(delay);
                        __set_current_state(TASK_RUNNING);
                }
        } while (!kthread_should_stop());
@@ -1488,15 +1559,38 @@ struct btrfs_root *open_ctree(struct super_block *sb,
                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;
@@ -1508,28 +1602,33 @@ struct btrfs_root *open_ctree(struct super_block *sb,
        INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
        INIT_LIST_HEAD(&fs_info->space_info);
        btrfs_mapping_init(&fs_info->mapping_tree);
+       btrfs_init_block_rsv(&fs_info->global_block_rsv);
+       btrfs_init_block_rsv(&fs_info->delalloc_block_rsv);
+       btrfs_init_block_rsv(&fs_info->trans_block_rsv);
+       btrfs_init_block_rsv(&fs_info->chunk_block_rsv);
+       btrfs_init_block_rsv(&fs_info->empty_block_rsv);
+       INIT_LIST_HEAD(&fs_info->durable_block_rsv_list);
+       mutex_init(&fs_info->durable_block_rsv_mutex);
        atomic_set(&fs_info->nr_async_submits, 0);
        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
@@ -1539,6 +1638,7 @@ 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);
@@ -1547,52 +1647,41 @@ 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,
-                            fs_info->btree_inode->i_mapping, GFP_NOFS);
-       extent_io_tree_init(&fs_info->pending_del,
+       extent_io_tree_init(&fs_info->freed_extents[0],
                             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);
 
@@ -1602,6 +1691,8 @@ struct btrfs_root *open_ctree(struct super_block *sb,
                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);
@@ -1621,35 +1712,42 @@ struct btrfs_root *open_ctree(struct super_block *sb,
        if (features) {
                printk(KERN_ERR "BTRFS: couldn't mount because of "
                       "unsupported optional features (%Lx).\n",
-                      features);
+                      (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",
-                      features);
+                      (unsigned long long)features);
                err = -EINVAL;
                goto fail_iput;
        }
 
-       /*
-        * 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->generic_worker,
+                          "genwork", 1, NULL);
+
        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);
 
        /* 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
@@ -1663,30 +1761,40 @@ 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->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_meta_workers,
-                           fs_info->thread_pool_size);
-       btrfs_start_workers(&fs_info->endio_write_workers,
-                           fs_info->thread_pool_size);
+       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);
 
        fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
        fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages,
@@ -1706,17 +1814,17 @@ 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;
        }
 
        mutex_lock(&fs_info->chunk_mutex);
-       ret = btrfs_read_sys_array(tree_root, btrfs_super_bytenr(disk_super));
+       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,
@@ -1730,16 +1838,24 @@ 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);
        if (ret) {
-               printk("btrfs: failed to read chunk tree on %s\n", sb->s_id);
+               printk(KERN_WARNING "btrfs: failed to read chunk tree on %s\n",
+                      sb->s_id);
                goto fail_chunk_root;
        }
 
@@ -1754,7 +1870,13 @@ struct btrfs_root *open_ctree(struct super_block *sb,
                                          blocksize, generation);
        if (!tree_root->node)
                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);
@@ -1764,41 +1886,54 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 
        ret = find_and_setup_root(tree_root, fs_info,
                                  BTRFS_DEV_TREE_OBJECTID, dev_root);
-       dev_root->track_dirty = 1;
-
        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;
 
        csum_root->track_dirty = 1;
 
-       btrfs_read_block_groups(extent_root);
-
-       fs_info->generation = generation + 1;
+       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;
+
+       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->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
                                               "btrfs-cleaner");
-       if (!fs_info->cleaner_kthread)
-               goto fail_csum_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) {
                u64 bytenr = btrfs_super_log_root(disk_super);
 
                if (fs_devices->rw_devices == 0) {
-                       printk("Btrfs log replay required on RO media\n");
+                       printk(KERN_WARNING "Btrfs log replay required "
+                              "on RO media\n");
                        err = -EIO;
                        goto fail_trans_kthread;
                }
@@ -1824,9 +1959,20 @@ struct btrfs_root *open_ctree(struct super_block *sb,
                }
        }
 
+       ret = btrfs_find_orphan_roots(tree_root);
+       BUG_ON(ret);
+
        if (!(sb->s_flags & MS_RDONLY)) {
-               ret = btrfs_cleanup_reloc_trees(tree_root);
+               ret = btrfs_cleanup_fs_roots(fs_info);
                BUG_ON(ret);
+
+               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;
@@ -1836,6 +1982,13 @@ struct btrfs_root *open_ctree(struct super_block *sb,
        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:
@@ -1850,34 +2003,45 @@ fail_cleaner:
        filemap_write_and_wait(fs_info->btree_inode->i_mapping);
        invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
 
-fail_csum_root:
+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);
+       free_extent_buffer(tree_root->commit_root);
 fail_chunk_root:
        free_extent_buffer(chunk_root->node);
-fail_sys_array:
-       free_extent_buffer(dev_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);
 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);
@@ -1947,6 +2111,17 @@ struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
        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)
@@ -1982,12 +2157,16 @@ static int write_dev_supers(struct btrfs_device *device,
                        bh = __find_get_block(device->bdev, bytenr / 4096,
                                              BTRFS_SUPER_INFO_SIZE);
                        BUG_ON(!bh);
-                       brelse(bh);
                        wait_on_buffer(bh);
-                       if (buffer_uptodate(bh)) {
-                               brelse(bh);
-                               continue;
-                       }
+                       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);
 
@@ -1998,12 +2177,18 @@ static int write_dev_supers(struct btrfs_device *device,
                                              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);
 
-                       set_buffer_uptodate(bh);
+                       /* one reference for submit_bh */
                        get_bh(bh);
+
+                       set_buffer_uptodate(bh);
                        lock_buffer(bh);
                        bh->b_end_io = btrfs_end_buffer_write_sync;
                }
@@ -2015,31 +2200,24 @@ static int write_dev_supers(struct btrfs_device *device,
                                       device->name);
                                set_buffer_uptodate(bh);
                                device->barriers = 0;
+                               /* one reference for submit_bh */
                                get_bh(bh);
                                lock_buffer(bh);
-                               ret = submit_bh(WRITE, bh);
+                               ret = submit_bh(WRITE_SYNC, bh);
                        }
                } else {
-                       ret = submit_bh(WRITE, bh);
+                       ret = submit_bh(WRITE_SYNC, bh);
                }
 
-               if (!ret && wait) {
-                       wait_on_buffer(bh);
-                       if (!buffer_uptodate(bh))
-                               errors++;
-               } else if (ret) {
+               if (ret)
                        errors++;
-               }
-               if (wait)
-                       brelse(bh);
        }
        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;
@@ -2054,8 +2232,10 @@ int write_all_supers(struct btrfs_root *root, int max_mirrors)
 
        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;
@@ -2082,13 +2262,13 @@ int write_all_supers(struct btrfs_root *root, int max_mirrors)
                        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);
+       list_for_each_entry(dev, head, dev_list) {
                if (!dev->bdev)
                        continue;
                if (!dev->in_fs_metadata || !dev->writeable)
@@ -2098,8 +2278,10 @@ int write_all_supers(struct btrfs_root *root, int 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;
@@ -2116,24 +2298,29 @@ int write_ctree_super(struct btrfs_trans_handle *trans,
 
 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);
+       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);
        }
-#if 0
-       if (root->in_sysfs)
-               btrfs_sysfs_del_root(root);
-#endif
-       if (root->node)
-               free_extent_buffer(root->node);
-       if (root->commit_root)
-               free_extent_buffer(root->commit_root);
-       if (root->name)
-               kfree(root->name);
+       free_extent_buffer(root->node);
+       free_extent_buffer(root->commit_root);
+       kfree(root->name);
        kfree(root);
-       return 0;
 }
 
 static int del_fs_roots(struct btrfs_fs_info *fs_info)
@@ -2142,7 +2329,21 @@ static int del_fs_roots(struct btrfs_fs_info *fs_info)
        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));
@@ -2167,11 +2368,10 @@ int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
                                             ARRAY_SIZE(gang));
                if (!ret)
                        break;
+
+               root_objectid = gang[ret - 1]->root_key.objectid + 1;
                for (i = 0; i < ret; i++) {
                        root_objectid = gang[i]->root_key.objectid;
-                       ret = btrfs_find_dead_roots(fs_info->tree_root,
-                                                   root_objectid, gang[i]);
-                       BUG_ON(ret);
                        btrfs_orphan_cleanup(gang[i]);
                }
                root_objectid++;
@@ -2185,13 +2385,19 @@ int btrfs_commit_super(struct btrfs_root *root)
        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);
-       trans = btrfs_start_transaction(root, 1);
+
+       /* wait until ongoing cleanup work done */
+       down_write(&root->fs_info->cleanup_work_sem);
+       up_write(&root->fs_info->cleanup_work_sem);
+
+       trans = btrfs_join_transaction(root, 1);
        ret = btrfs_commit_transaction(trans, root);
        BUG_ON(ret);
        /* run commit again to drop the original snapshot */
-       trans = btrfs_start_transaction(root, 1);
+       trans = btrfs_join_transaction(root, 1);
        btrfs_commit_transaction(trans, root);
        ret = btrfs_write_and_wait_transaction(NULL, root);
        BUG_ON(ret);
@@ -2208,39 +2414,37 @@ int close_ctree(struct btrfs_root *root)
        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("btrfs: commit super returns %d\n", ret);
-               }
+               if (ret)
+                       printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
        }
 
+       kthread_stop(root->fs_info->transaction_kthread);
+       kthread_stop(root->fs_info->cleaner_kthread);
+
+       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);
-
-       if (root->fs_info->csum_root->node);
-               free_extent_buffer(root->fs_info->csum_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);
 
@@ -2248,28 +2452,21 @@ int close_ctree(struct btrfs_root *root)
 
        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);
 
-#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);
@@ -2284,7 +2481,8 @@ 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;
 
@@ -2305,15 +2503,24 @@ 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)
@@ -2322,17 +2529,14 @@ 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);
@@ -2345,9 +2549,8 @@ 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;
 }
 
@@ -2369,9 +2572,17 @@ 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: