Merge branch 'linus' into x86/apic

Conflicts:
	arch/x86/kernel/acpi/boot.c
	arch/x86/mm/fault.c

26 files changed, 1406 insertions, 469 deletions

diff --git a/fs/btrfs/Kconfig b/fs/btrfs/Kconfig
index f8fcf999ea1b..7bb3c020e570 100644
--- a/fs/btrfs/Kconfig
+++ b/fs/btrfs/Kconfig
@@ -16,3 +16,16 @@ config BTRFS_FS
           module will be called btrfs.
 
           If unsure, say N.
+
+config BTRFS_FS_POSIX_ACL
+        bool "Btrfs POSIX Access Control Lists"
+        depends on BTRFS_FS
+        select FS_POSIX_ACL
+        help
+          POSIX Access Control Lists (ACLs) support permissions for users and
+          groups beyond the owner/group/world scheme.
+
+          To learn more about Access Control Lists, visit the POSIX ACLs for
+          Linux website <http://acl.bestbits.at/>.
+
+          If you don't know what Access Control Lists are, say N
diff --git a/fs/btrfs/async-thread.c b/fs/btrfs/async-thread.c
index 8e2fec05dbe0..c84ca1f5259a 100644
--- a/fs/btrfs/async-thread.c
+++ b/fs/btrfs/async-thread.c
@@ -16,11 +16,11 @@
  * Boston, MA 021110-1307, USA.
  */
 
-#include <linux/version.h>
 #include <linux/kthread.h>
 #include <linux/list.h>
 #include <linux/spinlock.h>
-# include <linux/freezer.h>
+#include <linux/freezer.h>
+#include <linux/ftrace.h>
 #include "async-thread.h"
 
 #define WORK_QUEUED_BIT 0
@@ -143,6 +143,7 @@ static int worker_loop(void *arg)
         struct btrfs_work *work;
         do {
                 spin_lock_irq(&worker->lock);
+again_locked:
                 while (!list_empty(&worker->pending)) {
                         cur = worker->pending.next;
                         work = list_entry(cur, struct btrfs_work, list);
@@ -165,14 +166,50 @@ static int worker_loop(void *arg)
                         check_idle_worker(worker);
 
                 }
-                worker->working = 0;
                 if (freezing(current)) {
+                        worker->working = 0;
+                        spin_unlock_irq(&worker->lock);
                         refrigerator();
                 } else {
-                        set_current_state(TASK_INTERRUPTIBLE);
                         spin_unlock_irq(&worker->lock);
-                        if (!kthread_should_stop())
+                        if (!kthread_should_stop()) {
+                                cpu_relax();
+                                /*
+                                 * we've dropped the lock, did someone else
+                                 * jump_in?
+                                 */
+                                smp_mb();
+                                if (!list_empty(&worker->pending))
+                                        continue;
+
+                                /*
+                                 * this short schedule allows more work to
+                                 * come in without the queue functions
+                                 * needing to go through wake_up_process()
+                                 *
+                                 * worker->working is still 1, so nobody
+                                 * is going to try and wake us up
+                                 */
+                                schedule_timeout(1);
+                                smp_mb();
+                                if (!list_empty(&worker->pending))
+                                        continue;
+
+                                /* still no more work?, sleep for real */
+                                spin_lock_irq(&worker->lock);
+                                set_current_state(TASK_INTERRUPTIBLE);
+                                if (!list_empty(&worker->pending))
+                                        goto again_locked;
+
+                                /*
+                                 * this makes sure we get a wakeup when someone
+                                 * adds something new to the queue
+                                 */
+                                worker->working = 0;
+                                spin_unlock_irq(&worker->lock);
+
                                 schedule();
+                        }
                         __set_current_state(TASK_RUNNING);
                 }
         } while (!kthread_should_stop());
@@ -350,13 +387,14 @@ int btrfs_requeue_work(struct btrfs_work *work)
 {
         struct btrfs_worker_thread *worker = work->worker;
         unsigned long flags;
+        int wake = 0;
 
         if (test_and_set_bit(WORK_QUEUED_BIT, &work->flags))
                 goto out;
 
         spin_lock_irqsave(&worker->lock, flags);
-        atomic_inc(&worker->num_pending);
         list_add_tail(&work->list, &worker->pending);
+        atomic_inc(&worker->num_pending);
 
         /* by definition we're busy, take ourselves off the idle
          * list
@@ -368,10 +406,16 @@ int btrfs_requeue_work(struct btrfs_work *work)
                                &worker->workers->worker_list);
                 spin_unlock_irqrestore(&worker->workers->lock, flags);
         }
+        if (!worker->working) {
+                wake = 1;
+                worker->working = 1;
+        }
 
         spin_unlock_irqrestore(&worker->lock, flags);
-
+        if (wake)
+                wake_up_process(worker->task);
 out:
+
         return 0;
 }
 
@@ -398,9 +442,10 @@ int btrfs_queue_worker(struct btrfs_workers *workers, struct btrfs_work *work)
         }
 
         spin_lock_irqsave(&worker->lock, flags);
+
+        list_add_tail(&work->list, &worker->pending);
         atomic_inc(&worker->num_pending);
         check_busy_worker(worker);
-        list_add_tail(&work->list, &worker->pending);
 
         /*
          * avoid calling into wake_up_process if this thread has already
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index ee848d8585d9..ab07627084f1 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -32,7 +32,6 @@
 #include <linux/swap.h>
 #include <linux/writeback.h>
 #include <linux/bit_spinlock.h>
-#include <linux/version.h>
 #include <linux/pagevec.h>
 #include "compat.h"
 #include "ctree.h"
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 9e46c0776816..35443cc4b9a9 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -54,6 +54,31 @@ struct btrfs_path *btrfs_alloc_path(void)
         return path;
 }
 
+/*
+ * set all locked nodes in the path to blocking locks.  This should
+ * be done before scheduling
+ */
+noinline void btrfs_set_path_blocking(struct btrfs_path *p)
+{
+        int i;
+        for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
+                if (p->nodes[i] && p->locks[i])
+                        btrfs_set_lock_blocking(p->nodes[i]);
+        }
+}
+
+/*
+ * reset all the locked nodes in the patch to spinning locks.
+ */
+noinline void btrfs_clear_path_blocking(struct btrfs_path *p)
+{
+        int i;
+        for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
+                if (p->nodes[i] && p->locks[i])
+                        btrfs_clear_lock_blocking(p->nodes[i]);
+        }
+}
+
 /* this also releases the path */
 void btrfs_free_path(struct btrfs_path *p)
 {
@@ -272,6 +297,8 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans,
         if (IS_ERR(cow))
                 return PTR_ERR(cow);
 
+        /* cow is set to blocking by btrfs_init_new_buffer */
+
         copy_extent_buffer(cow, buf, 0, 0, cow->len);
         btrfs_set_header_bytenr(cow, cow->start);
         btrfs_set_header_generation(cow, trans->transid);
@@ -388,17 +415,20 @@ noinline int btrfs_cow_block(struct btrfs_trans_handle *trans,
                 WARN_ON(1);
         }
 
-        spin_lock(&root->fs_info->hash_lock);
         if (btrfs_header_generation(buf) == trans->transid &&
             btrfs_header_owner(buf) == root->root_key.objectid &&
             !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
                 *cow_ret = buf;
-                spin_unlock(&root->fs_info->hash_lock);
                 WARN_ON(prealloc_dest);
                 return 0;
         }
-        spin_unlock(&root->fs_info->hash_lock);
+
         search_start = buf->start & ~((u64)(1024 * 1024 * 1024) - 1);
+
+        if (parent)
+                btrfs_set_lock_blocking(parent);
+        btrfs_set_lock_blocking(buf);
+
         ret = __btrfs_cow_block(trans, root, buf, parent,
                                  parent_slot, cow_ret, search_start, 0,
                                  prealloc_dest);
@@ -504,6 +534,8 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans,
         if (parent_nritems == 1)
                 return 0;
 
+        btrfs_set_lock_blocking(parent);
+
         for (i = start_slot; i < end_slot; i++) {
                 int close = 1;
 
@@ -564,6 +596,7 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans,
                         search_start = last_block;
 
                 btrfs_tree_lock(cur);
+                btrfs_set_lock_blocking(cur);
                 err = __btrfs_cow_block(trans, root, cur, parent, i,
                                         &cur, search_start,
                                         min(16 * blocksize,
@@ -862,6 +895,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
                 return 0;
 
         mid = path->nodes[level];
+
         WARN_ON(!path->locks[level]);
         WARN_ON(btrfs_header_generation(mid) != trans->transid);
 
@@ -884,6 +918,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
                 /* promote the child to a root */
                 child = read_node_slot(root, mid, 0);
                 btrfs_tree_lock(child);
+                btrfs_set_lock_blocking(child);
                 BUG_ON(!child);
                 ret = btrfs_cow_block(trans, root, child, mid, 0, &child, 0);
                 BUG_ON(ret);
@@ -900,6 +935,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
 
                 add_root_to_dirty_list(root);
                 btrfs_tree_unlock(child);
+
                 path->locks[level] = 0;
                 path->nodes[level] = NULL;
                 clean_tree_block(trans, root, mid);
@@ -924,6 +960,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
         left = read_node_slot(root, parent, pslot - 1);
         if (left) {
                 btrfs_tree_lock(left);
+                btrfs_set_lock_blocking(left);
                 wret = btrfs_cow_block(trans, root, left,
                                        parent, pslot - 1, &left, 0);
                 if (wret) {
@@ -934,6 +971,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
         right = read_node_slot(root, parent, pslot + 1);
         if (right) {
                 btrfs_tree_lock(right);
+                btrfs_set_lock_blocking(right);
                 wret = btrfs_cow_block(trans, root, right,
                                        parent, pslot + 1, &right, 0);
                 if (wret) {
@@ -1109,6 +1147,8 @@ static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans,
                 u32 left_nr;
 
                 btrfs_tree_lock(left);
+                btrfs_set_lock_blocking(left);
+
                 left_nr = btrfs_header_nritems(left);
                 if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
                         wret = 1;
@@ -1155,7 +1195,10 @@ static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans,
          */
         if (right) {
                 u32 right_nr;
+
                 btrfs_tree_lock(right);
+                btrfs_set_lock_blocking(right);
+
                 right_nr = btrfs_header_nritems(right);
                 if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
                         wret = 1;
@@ -1210,8 +1253,7 @@ static noinline void reada_for_search(struct btrfs_root *root,
         struct btrfs_disk_key disk_key;
         u32 nritems;
         u64 search;
-        u64 lowest_read;
-        u64 highest_read;
+        u64 target;
         u64 nread = 0;
         int direction = path->reada;
         struct extent_buffer *eb;
@@ -1235,8 +1277,7 @@ static noinline void reada_for_search(struct btrfs_root *root,
                 return;
         }
 
-        highest_read = search;
-        lowest_read = search;
+        target = search;
 
         nritems = btrfs_header_nritems(node);
         nr = slot;
@@ -1256,27 +1297,80 @@ static noinline void reada_for_search(struct btrfs_root *root,
                                 break;
                 }
                 search = btrfs_node_blockptr(node, nr);
-                if ((search >= lowest_read && search <= highest_read) ||
-                    (search < lowest_read && lowest_read - search <= 16384) ||
-                    (search > highest_read && search - highest_read <= 16384)) {
+                if ((search <= target && target - search <= 65536) ||
+                    (search > target && search - target <= 65536)) {
                         readahead_tree_block(root, search, blocksize,
                                      btrfs_node_ptr_generation(node, nr));
                         nread += blocksize;
                 }
                 nscan++;
-                if (path->reada < 2 && (nread > (64 * 1024) || nscan > 32))
+                if ((nread > 65536 || nscan > 32))
                         break;
+        }
+}
 
-                if (nread > (256 * 1024) || nscan > 128)
-                        break;
+/*
+ * returns -EAGAIN if it had to drop the path, or zero if everything was in
+ * cache
+ */
+static noinline int reada_for_balance(struct btrfs_root *root,
+                                      struct btrfs_path *path, int level)
+{
+        int slot;
+        int nritems;
+        struct extent_buffer *parent;
+        struct extent_buffer *eb;
+        u64 gen;
+        u64 block1 = 0;
+        u64 block2 = 0;
+        int ret = 0;
+        int blocksize;
 
-                if (search < lowest_read)
-                        lowest_read = search;
-                if (search > highest_read)
-                        highest_read = search;
+        parent = path->nodes[level - 1];
+        if (!parent)
+                return 0;
+
+        nritems = btrfs_header_nritems(parent);
+        slot = path->slots[level];
+        blocksize = btrfs_level_size(root, level);
+
+        if (slot > 0) {
+                block1 = btrfs_node_blockptr(parent, slot - 1);
+                gen = btrfs_node_ptr_generation(parent, slot - 1);
+                eb = btrfs_find_tree_block(root, block1, blocksize);
+                if (eb && btrfs_buffer_uptodate(eb, gen))
+                        block1 = 0;
+                free_extent_buffer(eb);
+        }
+        if (slot < nritems) {
+                block2 = btrfs_node_blockptr(parent, slot + 1);
+                gen = btrfs_node_ptr_generation(parent, slot + 1);
+                eb = btrfs_find_tree_block(root, block2, blocksize);
+                if (eb && btrfs_buffer_uptodate(eb, gen))
+                        block2 = 0;
+                free_extent_buffer(eb);
+        }
+        if (block1 || block2) {
+                ret = -EAGAIN;
+                btrfs_release_path(root, path);
+                if (block1)
+                        readahead_tree_block(root, block1, blocksize, 0);
+                if (block2)
+                        readahead_tree_block(root, block2, blocksize, 0);
+
+                if (block1) {
+                        eb = read_tree_block(root, block1, blocksize, 0);
+                        free_extent_buffer(eb);
+                }
+                if (block1) {
+                        eb = read_tree_block(root, block2, blocksize, 0);
+                        free_extent_buffer(eb);
+                }
         }
+        return ret;
 }
 
+
 /*
  * when we walk down the tree, it is usually safe to unlock the higher layers
  * in the tree.  The exceptions are when our path goes through slot 0, because
@@ -1328,6 +1422,32 @@ static noinline void unlock_up(struct btrfs_path *path, int level,
 }
 
 /*
+ * This releases any locks held in the path starting at level and
+ * going all the way up to the root.
+ *
+ * btrfs_search_slot will keep the lock held on higher nodes in a few
+ * corner cases, such as COW of the block at slot zero in the node.  This
+ * ignores those rules, and it should only be called when there are no
+ * more updates to be done higher up in the tree.
+ */
+noinline void btrfs_unlock_up_safe(struct btrfs_path *path, int level)
+{
+        int i;
+
+        if (path->keep_locks || path->lowest_level)
+                return;
+
+        for (i = level; i < BTRFS_MAX_LEVEL; i++) {
+                if (!path->nodes[i])
+                        continue;
+                if (!path->locks[i])
+                        continue;
+                btrfs_tree_unlock(path->nodes[i]);
+                path->locks[i] = 0;
+        }
+}
+
+/*
  * look for key in the tree.  path is filled in with nodes along the way
  * if key is found, we return zero and you can find the item in the leaf
  * level of the path (level 0)
@@ -1387,32 +1507,30 @@ again:
                         int wret;
 
                         /* is a cow on this block not required */
-                        spin_lock(&root->fs_info->hash_lock);
                         if (btrfs_header_generation(b) == trans->transid &&
                             btrfs_header_owner(b) == root->root_key.objectid &&
                             !btrfs_header_flag(b, BTRFS_HEADER_FLAG_WRITTEN)) {
-                                spin_unlock(&root->fs_info->hash_lock);
                                 goto cow_done;
                         }
-                        spin_unlock(&root->fs_info->hash_lock);
 
                         /* ok, we have to cow, is our old prealloc the right
                          * size?
                          */
                         if (prealloc_block.objectid &&
                             prealloc_block.offset != b->len) {
+                                btrfs_release_path(root, p);
                                 btrfs_free_reserved_extent(root,
                                            prealloc_block.objectid,
                                            prealloc_block.offset);
                                 prealloc_block.objectid = 0;
+                                goto again;
                         }
 
                         /*
                          * for higher level blocks, try not to allocate blocks
                          * with the block and the parent locks held.
                          */
-                        if (level > 1 && !prealloc_block.objectid &&
-                            btrfs_path_lock_waiting(p, level)) {
+                        if (level > 0 && !prealloc_block.objectid) {
                                 u32 size = b->len;
                                 u64 hint = b->start;
 
@@ -1425,6 +1543,8 @@ again:
                                 goto again;
                         }
 
+                        btrfs_set_path_blocking(p);
+
                         wret = btrfs_cow_block(trans, root, b,
                                                p->nodes[level + 1],
                                                p->slots[level + 1],
@@ -1446,6 +1566,22 @@ cow_done:
                 if (!p->skip_locking)
                         p->locks[level] = 1;
 
+                btrfs_clear_path_blocking(p);
+
+                /*
+                 * we have a lock on b and as long as we aren't changing
+                 * the tree, there is no way to for the items in b to change.
+                 * It is safe to drop the lock on our parent before we
+                 * go through the expensive btree search on b.
+                 *
+                 * If cow is true, then we might be changing slot zero,
+                 * which may require changing the parent.  So, we can't
+                 * drop the lock until after we know which slot we're
+                 * operating on.
+                 */
+                if (!cow)
+                        btrfs_unlock_up_safe(p, level + 1);
+
                 ret = check_block(root, p, level);
                 if (ret) {
                         ret = -1;
@@ -1453,6 +1589,7 @@ cow_done:
                 }
 
                 ret = bin_search(b, key, level, &slot);
+
                 if (level != 0) {
                         if (ret && slot > 0)
                                 slot -= 1;
@@ -1460,7 +1597,16 @@ cow_done:
                         if ((p->search_for_split || ins_len > 0) &&
                             btrfs_header_nritems(b) >=
                             BTRFS_NODEPTRS_PER_BLOCK(root) - 3) {
-                                int sret = split_node(trans, root, p, level);
+                                int sret;
+
+                                sret = reada_for_balance(root, p, level);
+                                if (sret)
+                                        goto again;
+
+                                btrfs_set_path_blocking(p);
+                                sret = split_node(trans, root, p, level);
+                                btrfs_clear_path_blocking(p);
+
                                 BUG_ON(sret > 0);
                                 if (sret) {
                                         ret = sret;
@@ -1468,9 +1614,19 @@ cow_done:
                                 }
                                 b = p->nodes[level];
                                 slot = p->slots[level];
-                        } else if (ins_len < 0) {
-                                int sret = balance_level(trans, root, p,
-                                                         level);
+                        } else if (ins_len < 0 &&
+                                   btrfs_header_nritems(b) <
+                                   BTRFS_NODEPTRS_PER_BLOCK(root) / 4) {
+                                int sret;
+
+                                sret = reada_for_balance(root, p, level);
+                                if (sret)
+                                        goto again;
+
+                                btrfs_set_path_blocking(p);
+                                sret = balance_level(trans, root, p, level);
+                                btrfs_clear_path_blocking(p);
+
                                 if (sret) {
                                         ret = sret;
                                         goto done;
@@ -1504,7 +1660,7 @@ cow_done:
                                  * of the btree by dropping locks before
                                  * we read.
                                  */
-                                if (level > 1) {
+                                if (level > 0) {
                                         btrfs_release_path(NULL, p);
                                         if (tmp)
                                                 free_extent_buffer(tmp);
@@ -1519,6 +1675,7 @@ cow_done:
                                                 free_extent_buffer(tmp);
                                         goto again;
                                 } else {
+                                        btrfs_set_path_blocking(p);
                                         if (tmp)
                                                 free_extent_buffer(tmp);
                                         if (should_reada)
@@ -1528,14 +1685,29 @@ cow_done:
                                         b = read_node_slot(root, b, slot);
                                 }
                         }
-                        if (!p->skip_locking)
-                                btrfs_tree_lock(b);
+                        if (!p->skip_locking) {
+                                int lret;
+
+                                btrfs_clear_path_blocking(p);
+                                lret = btrfs_try_spin_lock(b);
+
+                                if (!lret) {
+                                        btrfs_set_path_blocking(p);
+                                        btrfs_tree_lock(b);
+                                        btrfs_clear_path_blocking(p);
+                                }
+                        }
                 } else {
                         p->slots[level] = slot;
                         if (ins_len > 0 &&
                             btrfs_leaf_free_space(root, b) < ins_len) {
-                                int sret = split_leaf(trans, root, key,
+                                int sret;
+
+                                btrfs_set_path_blocking(p);
+                                sret = split_leaf(trans, root, key,
                                                       p, ins_len, ret == 0);
+                                btrfs_clear_path_blocking(p);
+
                                 BUG_ON(sret > 0);
                                 if (sret) {
                                         ret = sret;
@@ -1549,12 +1721,16 @@ cow_done:
         }
         ret = 1;
 done:
+        /*
+         * we don't really know what they plan on doing with the path
+         * from here on, so for now just mark it as blocking
+         */
+        btrfs_set_path_blocking(p);
         if (prealloc_block.objectid) {
                 btrfs_free_reserved_extent(root,
                            prealloc_block.objectid,
                            prealloc_block.offset);
         }
-
         return ret;
 }
 
@@ -1578,6 +1754,8 @@ int btrfs_merge_path(struct btrfs_trans_handle *trans,
         ret = btrfs_cow_block(trans, root, eb, NULL, 0, &eb, 0);
         BUG_ON(ret);
 
+        btrfs_set_lock_blocking(eb);
+
         parent = eb;
         while (1) {
                 level = btrfs_header_level(parent);
@@ -1602,6 +1780,7 @@ int btrfs_merge_path(struct btrfs_trans_handle *trans,
                         eb = read_tree_block(root, bytenr, blocksize,
                                              generation);
                         btrfs_tree_lock(eb);
+                        btrfs_set_lock_blocking(eb);
                 }
 
                 /*
@@ -1626,6 +1805,7 @@ int btrfs_merge_path(struct btrfs_trans_handle *trans,
                                 eb = read_tree_block(root, bytenr, blocksize,
                                                 generation);
                                 btrfs_tree_lock(eb);
+                                btrfs_set_lock_blocking(eb);
                         }
 
                         ret = btrfs_cow_block(trans, root, eb, parent, slot,
@@ -2172,6 +2352,8 @@ static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
 
         right = read_node_slot(root, upper, slot + 1);
         btrfs_tree_lock(right);
+        btrfs_set_lock_blocking(right);
+
         free_space = btrfs_leaf_free_space(root, right);
         if (free_space < data_size)
                 goto out_unlock;
@@ -2367,6 +2549,8 @@ static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
 
         left = read_node_slot(root, path->nodes[1], slot - 1);
         btrfs_tree_lock(left);
+        btrfs_set_lock_blocking(left);
+
         free_space = btrfs_leaf_free_space(root, left);
         if (free_space < data_size) {
                 ret = 1;
@@ -2825,6 +3009,12 @@ int btrfs_split_item(struct btrfs_trans_handle *trans,
         path->keep_locks = 0;
         BUG_ON(ret);
 
+        /*
+         * make sure any changes to the path from split_leaf leave it
+         * in a blocking state
+         */
+        btrfs_set_path_blocking(path);
+
         leaf = path->nodes[0];
         BUG_ON(btrfs_leaf_free_space(root, leaf) < sizeof(struct btrfs_item));
 
@@ -3354,6 +3544,7 @@ int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
                 BUG();
         }
 out:
+        btrfs_unlock_up_safe(path, 1);
         return ret;
 }
 
@@ -3441,15 +3632,22 @@ noinline int btrfs_del_leaf(struct btrfs_trans_handle *trans,
 {
         int ret;
         u64 root_gen = btrfs_header_generation(path->nodes[1]);
+        u64 parent_start = path->nodes[1]->start;
+        u64 parent_owner = btrfs_header_owner(path->nodes[1]);
 
         ret = del_ptr(trans, root, path, 1, path->slots[1]);
         if (ret)
                 return ret;
 
+        /*
+         * btrfs_free_extent is expensive, we want to make sure we
+         * aren't holding any locks when we call it
+         */
+        btrfs_unlock_up_safe(path, 0);
+
         ret = btrfs_free_extent(trans, root, bytenr,
                                 btrfs_level_size(root, 0),
-                                path->nodes[1]->start,
-                                btrfs_header_owner(path->nodes[1]),
+                                parent_start, parent_owner,
                                 root_gen, 0, 1);
         return ret;
 }
@@ -3721,12 +3919,14 @@ find_next_key:
                  */
                 if (slot >= nritems) {
                         path->slots[level] = slot;
+                        btrfs_set_path_blocking(path);
                         sret = btrfs_find_next_key(root, path, min_key, level,
                                                   cache_only, min_trans);
                         if (sret == 0) {
                                 btrfs_release_path(root, path);
                                 goto again;
                         } else {
+                                btrfs_clear_path_blocking(path);
                                 goto out;
                         }
                 }
@@ -3738,16 +3938,20 @@ find_next_key:
                         unlock_up(path, level, 1);
                         goto out;
                 }
+                btrfs_set_path_blocking(path);
                 cur = read_node_slot(root, cur, slot);
 
                 btrfs_tree_lock(cur);
+
                 path->locks[level - 1] = 1;
                 path->nodes[level - 1] = cur;
                 unlock_up(path, level, 1);
+                btrfs_clear_path_blocking(path);
         }
 out:
         if (ret == 0)
                 memcpy(min_key, &found_key, sizeof(found_key));
+        btrfs_set_path_blocking(path);
         return ret;
 }
 
@@ -3843,6 +4047,7 @@ int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
         if (ret < 0)
                 return ret;
 
+        btrfs_set_path_blocking(path);
         nritems = btrfs_header_nritems(path->nodes[0]);
         /*
          * by releasing the path above we dropped all our locks.  A balance
@@ -3873,6 +4078,7 @@ int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
                         free_extent_buffer(next);
                 }
 
+                /* the path was set to blocking above */
                 if (level == 1 && (path->locks[1] || path->skip_locking) &&
                     path->reada)
                         reada_for_search(root, path, level, slot, 0);
@@ -3881,6 +4087,7 @@ int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
                 if (!path->skip_locking) {
                         WARN_ON(!btrfs_tree_locked(c));
                         btrfs_tree_lock(next);
+                        btrfs_set_lock_blocking(next);
                 }
                 break;
         }
@@ -3897,12 +4104,15 @@ int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
                         path->locks[level] = 1;
                 if (!level)
                         break;
+
+                btrfs_set_path_blocking(path);
                 if (level == 1 && path->locks[1] && path->reada)
                         reada_for_search(root, path, level, slot, 0);
                 next = read_node_slot(root, next, 0);
                 if (!path->skip_locking) {
                         WARN_ON(!btrfs_tree_locked(path->nodes[level]));
                         btrfs_tree_lock(next);
+                        btrfs_set_lock_blocking(next);
                 }
         }
 done:
@@ -3927,6 +4137,7 @@ int btrfs_previous_item(struct btrfs_root *root,
 
         while (1) {
                 if (path->slots[0] == 0) {
+                        btrfs_set_path_blocking(path);
                         ret = btrfs_prev_leaf(root, path);
                         if (ret != 0)
                                 return ret;
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index eee060f88113..531db112c8bd 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -454,17 +454,11 @@ struct btrfs_timespec {
         __le32 nsec;
 } __attribute__ ((__packed__));
 
-typedef enum {
+enum btrfs_compression_type {
         BTRFS_COMPRESS_NONE = 0,
         BTRFS_COMPRESS_ZLIB = 1,
         BTRFS_COMPRESS_LAST = 2,
-} btrfs_compression_type;
-
-/* we don't understand any encryption methods right now */
-typedef enum {
-        BTRFS_ENCRYPTION_NONE = 0,
-        BTRFS_ENCRYPTION_LAST = 1,
-} btrfs_encryption_type;
+};
 
 struct btrfs_inode_item {
         /* nfs style generation number */
@@ -701,9 +695,7 @@ struct btrfs_fs_info {
         struct btrfs_transaction *running_transaction;
         wait_queue_head_t transaction_throttle;
         wait_queue_head_t transaction_wait;
-
         wait_queue_head_t async_submit_wait;
-        wait_queue_head_t tree_log_wait;
 
         struct btrfs_super_block super_copy;
         struct btrfs_super_block super_for_commit;
@@ -711,7 +703,6 @@ struct btrfs_fs_info {
         struct super_block *sb;
         struct inode *btree_inode;
         struct backing_dev_info bdi;
-        spinlock_t hash_lock;
         struct mutex trans_mutex;
         struct mutex tree_log_mutex;
         struct mutex transaction_kthread_mutex;
@@ -730,10 +721,6 @@ struct btrfs_fs_info {
         atomic_t async_submit_draining;
         atomic_t nr_async_bios;
         atomic_t async_delalloc_pages;
-        atomic_t tree_log_writers;
-        atomic_t tree_log_commit;
-        unsigned long tree_log_batch;
-        u64 tree_log_transid;
 
         /*
          * this is used by the balancing code to wait for all the pending
@@ -833,7 +820,14 @@ struct btrfs_root {
         struct kobject root_kobj;
         struct completion kobj_unregister;
         struct mutex objectid_mutex;
+
         struct mutex log_mutex;
+        wait_queue_head_t log_writer_wait;
+        wait_queue_head_t log_commit_wait[2];
+        atomic_t log_writers;
+        atomic_t log_commit[2];
+        unsigned long log_transid;
+        unsigned long log_batch;
 
         u64 objectid;
         u64 last_trans;
@@ -1841,6 +1835,10 @@ void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p);
 struct btrfs_path *btrfs_alloc_path(void);
 void btrfs_free_path(struct btrfs_path *p);
 void btrfs_init_path(struct btrfs_path *p);
+void btrfs_set_path_blocking(struct btrfs_path *p);
+void btrfs_clear_path_blocking(struct btrfs_path *p);
+void btrfs_unlock_up_safe(struct btrfs_path *p, int level);
+
 int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
                    struct btrfs_path *path, int slot, int nr);
 int btrfs_del_leaf(struct btrfs_trans_handle *trans,
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 81a313874ae5..5aebddd71193 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -16,7 +16,6 @@
  * Boston, MA 021110-1307, USA.
  */
 
-#include <linux/version.h>
 #include <linux/fs.h>
 #include <linux/blkdev.h>
 #include <linux/scatterlist.h>
@@ -800,7 +799,7 @@ 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;
+                set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
         else
                 WARN_ON(1);
         return buf;
@@ -814,6 +813,10 @@ int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
         if (btrfs_header_generation(buf) ==
             root->fs_info->running_transaction->transid) {
                 WARN_ON(!btrfs_tree_locked(buf));
+
+                /* ugh, clear_extent_buffer_dirty can be expensive */
+                btrfs_set_lock_blocking(buf);
+
                 clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
                                           buf);
         }
@@ -850,6 +853,14 @@ static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
         spin_lock_init(&root->list_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;
         extent_io_tree_init(&root->dirty_log_pages,
                              fs_info->btree_inode->i_mapping, GFP_NOFS);
 
@@ -934,15 +945,16 @@ 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,
@@ -951,12 +963,23 @@ 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,
+                                      trans->transid, 0, 0, 0);
+        if (IS_ERR(leaf)) {
+                kfree(root);
+                return ERR_CAST(leaf);
+        }
 
+        root->node = leaf;
         btrfs_set_header_nritems(root->node, 0);
         btrfs_set_header_level(root->node, 0);
         btrfs_set_header_bytenr(root->node, root->node->start);
@@ -968,7 +991,48 @@ int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
                             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_bytenr(&log_root->root_item, log_root->node->start);
+        btrfs_set_root_generation(&log_root->root_item, trans->transid);
+
+        WARN_ON(root->log_root);
+        root->log_root = log_root;
+        root->log_transid = 0;
         return 0;
 }
 
@@ -1136,7 +1200,6 @@ 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
@@ -1144,8 +1207,7 @@ static int btrfs_congested_fn(void *congested_data, int bdi_bits)
             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);
@@ -1163,13 +1225,11 @@ 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;
 
@@ -1447,7 +1507,6 @@ struct btrfs_root *open_ctree(struct super_block *sb,
         INIT_LIST_HEAD(&fs_info->dead_roots);
         INIT_LIST_HEAD(&fs_info->hashers);
         INIT_LIST_HEAD(&fs_info->delalloc_inodes);
-        spin_lock_init(&fs_info->hash_lock);
         spin_lock_init(&fs_info->delalloc_lock);
         spin_lock_init(&fs_info->new_trans_lock);
         spin_lock_init(&fs_info->ref_cache_lock);
@@ -1535,10 +1594,6 @@ struct btrfs_root *open_ctree(struct super_block *sb,
         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;
 
         __setup_root(4096, 4096, 4096, 4096, tree_root,
                      fs_info, BTRFS_ROOT_TREE_OBJECTID);
@@ -1627,6 +1682,8 @@ struct btrfs_root *open_ctree(struct super_block *sb,
          * low idle thresh
          */
         fs_info->endio_workers.idle_thresh = 4;
+        fs_info->endio_meta_workers.idle_thresh = 4;
+
         fs_info->endio_write_workers.idle_thresh = 64;
         fs_info->endio_meta_write_workers.idle_thresh = 64;
 
@@ -1740,13 +1797,13 @@ struct btrfs_root *open_ctree(struct super_block *sb,
         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)
+        if (IS_ERR(fs_info->cleaner_kthread))
                 goto fail_csum_root;
 
         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_super_log_root(disk_super) != 0) {
@@ -1828,13 +1885,14 @@ fail_sb_buffer:
 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);
+        bdi_destroy(&fs_info->bdi);
 
+fail:
         kfree(extent_root);
         kfree(tree_root);
-        bdi_destroy(&fs_info->bdi);
         kfree(fs_info);
         kfree(chunk_root);
         kfree(dev_root);
@@ -1995,7 +2053,6 @@ static int write_dev_supers(struct btrfs_device *device,
 
 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 btrfs_device *dev;
         struct btrfs_super_block *sb;
@@ -2011,8 +2068,7 @@ 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);
+        list_for_each_entry(dev, head, dev_list) {
                 if (!dev->bdev) {
                         total_errors++;
                         continue;
@@ -2045,8 +2101,7 @@ int write_all_supers(struct btrfs_root *root, int max_mirrors)
         }
 
         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)
@@ -2260,6 +2315,8 @@ void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
         u64 transid = btrfs_header_generation(buf);
         struct inode *btree_inode = root->fs_info->btree_inode;
 
+        btrfs_set_lock_blocking(buf);
+
         WARN_ON(!btrfs_tree_locked(buf));
         if (transid != root->fs_info->generation) {
                 printk(KERN_CRIT "btrfs transid mismatch buffer %llu, "
@@ -2302,14 +2359,13 @@ int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
         int ret;
         ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
         if (ret == 0)
-                buf->flags |= EXTENT_UPTODATE;
+                set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
         return ret;
 }
 
 int btree_lock_page_hook(struct page *page)
 {
         struct inode *inode = page->mapping->host;
-        struct btrfs_root *root = BTRFS_I(inode)->root;
         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
         struct extent_buffer *eb;
         unsigned long len;
@@ -2324,9 +2380,7 @@ 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);
         btrfs_tree_unlock(eb);
         free_extent_buffer(eb);
 out:
diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h
index c0ff404c31b7..494a56eb2986 100644
--- a/fs/btrfs/disk-io.h
+++ b/fs/btrfs/disk-io.h
@@ -98,5 +98,7 @@ int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans,
                              struct btrfs_fs_info *fs_info);
 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
                              struct btrfs_fs_info *fs_info);
+int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
+                       struct btrfs_root *root);
 int btree_lock_page_hook(struct page *page);
 #endif
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 293da650873f..7527523c2d2d 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -19,7 +19,7 @@
 #include <linux/pagemap.h>
 #include <linux/writeback.h>
 #include <linux/blkdev.h>
-#include <linux/version.h>
+#include <linux/sort.h>
 #include "compat.h"
 #include "hash.h"
 #include "crc32c.h"
@@ -30,7 +30,6 @@
 #include "volumes.h"
 #include "locking.h"
 #include "ref-cache.h"
-#include "compat.h"
 
 #define PENDING_EXTENT_INSERT 0
 #define PENDING_EXTENT_DELETE 1
@@ -326,10 +325,8 @@ static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info,
                                                   u64 flags)
 {
         struct list_head *head = &info->space_info;
-        struct list_head *cur;
         struct btrfs_space_info *found;
-        list_for_each(cur, head) {
-                found = list_entry(cur, struct btrfs_space_info, list);
+        list_for_each_entry(found, head, list) {
                 if (found->flags == flags)
                         return found;
         }
@@ -1525,15 +1522,55 @@ out:
         return ret;
 }
 
-int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
-                  struct extent_buffer *orig_buf, struct extent_buffer *buf,
-                  u32 *nr_extents)
+/* when a block goes through cow, we update the reference counts of
+ * everything that block points to.  The internal pointers of the block
+ * can be in just about any order, and it is likely to have clusters of
+ * things that are close together and clusters of things that are not.
+ *
+ * To help reduce the seeks that come with updating all of these reference
+ * counts, sort them by byte number before actual updates are done.
+ *
+ * struct refsort is used to match byte number to slot in the btree block.
+ * we sort based on the byte number and then use the slot to actually
+ * find the item.
+ *
+ * struct refsort is smaller than strcut btrfs_item and smaller than
+ * struct btrfs_key_ptr.  Since we're currently limited to the page size
+ * for a btree block, there's no way for a kmalloc of refsorts for a
+ * single node to be bigger than a page.
+ */
+struct refsort {
+        u64 bytenr;
+        u32 slot;
+};
+
+/*
+ * for passing into sort()
+ */
+static int refsort_cmp(const void *a_void, const void *b_void)
+{
+        const struct refsort *a = a_void;
+        const struct refsort *b = b_void;
+
+        if (a->bytenr < b->bytenr)
+                return -1;
+        if (a->bytenr > b->bytenr)
+                return 1;
+        return 0;
+}
+
+
+noinline int btrfs_inc_ref(struct btrfs_trans_handle *trans,
+                           struct btrfs_root *root,
+                           struct extent_buffer *orig_buf,
+                           struct extent_buffer *buf, u32 *nr_extents)
 {
         u64 bytenr;
         u64 ref_root;
         u64 orig_root;
         u64 ref_generation;
         u64 orig_generation;
+        struct refsort *sorted;
         u32 nritems;
         u32 nr_file_extents = 0;
         struct btrfs_key key;
@@ -1542,6 +1579,8 @@ int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
         int level;
         int ret = 0;
         int faili = 0;
+        int refi = 0;
+        int slot;
         int (*process_func)(struct btrfs_trans_handle *, struct btrfs_root *,
                             u64, u64, u64, u64, u64, u64, u64, u64);
 
@@ -1553,6 +1592,9 @@ int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
         nritems = btrfs_header_nritems(buf);
         level = btrfs_header_level(buf);
 
+        sorted = kmalloc(sizeof(struct refsort) * nritems, GFP_NOFS);
+        BUG_ON(!sorted);
+
         if (root->ref_cows) {
                 process_func = __btrfs_inc_extent_ref;
         } else {
@@ -1565,6 +1607,11 @@ int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
                 process_func = __btrfs_update_extent_ref;
         }
 
+        /*
+         * we make two passes through the items.  In the first pass we
+         * only record the byte number and slot.  Then we sort based on
+         * byte number and do the actual work based on the sorted results
+         */
         for (i = 0; i < nritems; i++) {
                 cond_resched();
                 if (level == 0) {
@@ -1581,6 +1628,32 @@ int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
                                 continue;
 
                         nr_file_extents++;
+                        sorted[refi].bytenr = bytenr;
+                        sorted[refi].slot = i;
+                        refi++;
+                } else {
+                        bytenr = btrfs_node_blockptr(buf, i);
+                        sorted[refi].bytenr = bytenr;
+                        sorted[refi].slot = i;
+                        refi++;
+                }
+        }
+        /*
+         * if refi == 0, we didn't actually put anything into the sorted
+         * array and we're done
+         */
+        if (refi == 0)
+                goto out;
+
+        sort(sorted, refi, sizeof(struct refsort), refsort_cmp, NULL);
+
+        for (i = 0; i < refi; i++) {
+                cond_resched();
+                slot = sorted[i].slot;
+                bytenr = sorted[i].bytenr;
+
+                if (level == 0) {
+                        btrfs_item_key_to_cpu(buf, &key, slot);
 
                         ret = process_func(trans, root, bytenr,
                                            orig_buf->start, buf->start,
@@ -1589,25 +1662,25 @@ int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
                                            key.objectid);
 
                         if (ret) {
-                                faili = i;
+                                faili = slot;
                                 WARN_ON(1);
                                 goto fail;
                         }
                 } else {
-                        bytenr = btrfs_node_blockptr(buf, i);
                         ret = process_func(trans, root, bytenr,
                                            orig_buf->start, buf->start,
                                            orig_root, ref_root,
                                            orig_generation, ref_generation,
                                            level - 1);
                         if (ret) {
-                                faili = i;
+                                faili = slot;
                                 WARN_ON(1);
                                 goto fail;
                         }
                 }
         }
 out:
+        kfree(sorted);
         if (nr_extents) {
                 if (level == 0)
                         *nr_extents = nr_file_extents;
@@ -1616,6 +1689,7 @@ out:
         }
         return 0;
 fail:
+        kfree(sorted);
         WARN_ON(1);
         return ret;
 }
@@ -2159,7 +2233,8 @@ again:
                 ret = find_first_extent_bit(&info->extent_ins, search, &start,
                                             &end, EXTENT_WRITEBACK);
                 if (ret) {
-                        if (skipped && all && !num_inserts) {
+                        if (skipped && all && !num_inserts &&
+                            list_empty(&update_list)) {
                                 skipped = 0;
                                 search = 0;
                                 continue;
@@ -2547,6 +2622,7 @@ again:
                 if (ret) {
                         if (all && skipped && !nr) {
                                 search = 0;
+                                skipped = 0;
                                 continue;
                         }
                         mutex_unlock(&info->extent_ins_mutex);
@@ -2700,13 +2776,9 @@ static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
         /* if metadata always pin */
         if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID) {
                 if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
-                        struct btrfs_block_group_cache *cache;
-
-                        /* btrfs_free_reserved_extent */
-                        cache = btrfs_lookup_block_group(root->fs_info, bytenr);
-                        BUG_ON(!cache);
-                        btrfs_add_free_space(cache, bytenr, num_bytes);
-                        put_block_group(cache);
+                        mutex_lock(&root->fs_info->pinned_mutex);
+                        btrfs_update_pinned_extents(root, bytenr, num_bytes, 1);
+                        mutex_unlock(&root->fs_info->pinned_mutex);
                         update_reserved_extents(root, bytenr, num_bytes, 0);
                         return 0;
                 }
@@ -3014,7 +3086,6 @@ loop_check:
 static void dump_space_info(struct btrfs_space_info *info, u64 bytes)
 {
         struct btrfs_block_group_cache *cache;
-        struct list_head *l;
 
         printk(KERN_INFO "space_info has %llu free, is %sfull\n",
                (unsigned long long)(info->total_bytes - info->bytes_used -
@@ -3022,8 +3093,7 @@ static void dump_space_info(struct btrfs_space_info *info, u64 bytes)
                (info->full) ? "" : "not ");
 
         down_read(&info->groups_sem);
-        list_for_each(l, &info->block_groups) {
-                cache = list_entry(l, struct btrfs_block_group_cache, list);
+        list_for_each_entry(cache, &info->block_groups, list) {
                 spin_lock(&cache->lock);
                 printk(KERN_INFO "block group %llu has %llu bytes, %llu used "
                        "%llu pinned %llu reserved\n",
@@ -3342,7 +3412,10 @@ struct extent_buffer *btrfs_init_new_buffer(struct btrfs_trans_handle *trans,
         btrfs_set_header_generation(buf, trans->transid);
         btrfs_tree_lock(buf);
         clean_tree_block(trans, root, buf);
+
+        btrfs_set_lock_blocking(buf);
         btrfs_set_buffer_uptodate(buf);
+
         if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
                 set_extent_dirty(&root->dirty_log_pages, buf->start,
                          buf->start + buf->len - 1, GFP_NOFS);
@@ -3351,6 +3424,7 @@ struct extent_buffer *btrfs_init_new_buffer(struct btrfs_trans_handle *trans,
                          buf->start + buf->len - 1, GFP_NOFS);
         }
         trans->blocks_used++;
+        /* this returns a buffer locked for blocking */
         return buf;
 }
 
@@ -3388,36 +3462,73 @@ int btrfs_drop_leaf_ref(struct btrfs_trans_handle *trans,
 {
         u64 leaf_owner;
         u64 leaf_generation;
+        struct refsort *sorted;
         struct btrfs_key key;
         struct btrfs_file_extent_item *fi;
         int i;
         int nritems;
         int ret;
+        int refi = 0;
+        int slot;
 
         BUG_ON(!btrfs_is_leaf(leaf));
         nritems = btrfs_header_nritems(leaf);
         leaf_owner = btrfs_header_owner(leaf);
         leaf_generation = btrfs_header_generation(leaf);
 
+        sorted = kmalloc(sizeof(*sorted) * nritems, GFP_NOFS);
+        /* we do this loop twice.  The first time we build a list
+         * of the extents we have a reference on, then we sort the list
+         * by bytenr.  The second time around we actually do the
+         * extent freeing.
+         */
         for (i = 0; i < nritems; i++) {
                 u64 disk_bytenr;
                 cond_resched();
 
                 btrfs_item_key_to_cpu(leaf, &key, i);
+
+                /* only extents have references, skip everything else */
                 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
                         continue;
+
                 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
+
+                /* inline extents live in the btree, they don't have refs */
                 if (btrfs_file_extent_type(leaf, fi) ==
                     BTRFS_FILE_EXTENT_INLINE)
                         continue;
-                /*
-                 * FIXME make sure to insert a trans record that
-                 * repeats the snapshot del on crash
-                 */
+
                 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
+
+                /* holes don't have refs */
                 if (disk_bytenr == 0)
                         continue;
 
+                sorted[refi].bytenr = disk_bytenr;
+                sorted[refi].slot = i;
+                refi++;
+        }
+
+        if (refi == 0)
+                goto out;
+
+        sort(sorted, refi, sizeof(struct refsort), refsort_cmp, NULL);
+
+        for (i = 0; i < refi; i++) {
+                u64 disk_bytenr;
+
+                disk_bytenr = sorted[i].bytenr;
+                slot = sorted[i].slot;
+
+                cond_resched();
+
+                btrfs_item_key_to_cpu(leaf, &key, slot);
+                if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
+                        continue;
+
+                fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
+
                 ret = __btrfs_free_extent(trans, root, disk_bytenr,
                                 btrfs_file_extent_disk_num_bytes(leaf, fi),
                                 leaf->start, leaf_owner, leaf_generation,
@@ -3428,6 +3539,8 @@ int btrfs_drop_leaf_ref(struct btrfs_trans_handle *trans,
                 wake_up(&root->fs_info->transaction_throttle);
                 cond_resched();
         }
+out:
+        kfree(sorted);
         return 0;
 }
 
@@ -3437,9 +3550,25 @@ static noinline int cache_drop_leaf_ref(struct btrfs_trans_handle *trans,
 {
         int i;
         int ret;
-        struct btrfs_extent_info *info = ref->extents;
+        struct btrfs_extent_info *info;
+        struct refsort *sorted;
+
+        if (ref->nritems == 0)
+                return 0;
 
+        sorted = kmalloc(sizeof(*sorted) * ref->nritems, GFP_NOFS);
         for (i = 0; i < ref->nritems; i++) {
+                sorted[i].bytenr = ref->extents[i].bytenr;
+                sorted[i].slot = i;
+        }
+        sort(sorted, ref->nritems, sizeof(struct refsort), refsort_cmp, NULL);
+
+        /*
+         * the items in the ref were sorted when the ref was inserted
+         * into the ref cache, so this is already in order
+         */
+        for (i = 0; i < ref->nritems; i++) {
+                info = ref->extents + sorted[i].slot;
                 ret = __btrfs_free_extent(trans, root, info->bytenr,
                                           info->num_bytes, ref->bytenr,
                                           ref->owner, ref->generation,
@@ -3453,6 +3582,7 @@ static noinline int cache_drop_leaf_ref(struct btrfs_trans_handle *trans,
                 info++;
         }
 
+        kfree(sorted);
         return 0;
 }
 
@@ -3497,6 +3627,152 @@ static int drop_snap_lookup_refcount(struct btrfs_root *root, u64 start,
 }
 
 /*
+ * this is used while deleting old snapshots, and it drops the refs
+ * on a whole subtree starting from a level 1 node.
+ *
+ * The idea is to sort all the leaf pointers, and then drop the
+ * ref on all the leaves in order.  Most of the time the leaves
+ * will have ref cache entries, so no leaf IOs will be required to
+ * find the extents they have references on.
+ *
+ * For each leaf, any references it has are also dropped in order
+ *
+ * This ends up dropping the references in something close to optimal
+ * order for reading and modifying the extent allocation tree.
+ */
+static noinline int drop_level_one_refs(struct btrfs_trans_handle *trans,
+                                        struct btrfs_root *root,
+                                        struct btrfs_path *path)
+{
+        u64 bytenr;
+        u64 root_owner;
+        u64 root_gen;
+        struct extent_buffer *eb = path->nodes[1];
+        struct extent_buffer *leaf;
+        struct btrfs_leaf_ref *ref;
+        struct refsort *sorted = NULL;
+        int nritems = btrfs_header_nritems(eb);
+        int ret;
+        int i;
+        int refi = 0;
+        int slot = path->slots[1];
+        u32 blocksize = btrfs_level_size(root, 0);
+        u32 refs;
+
+        if (nritems == 0)
+                goto out;
+
+        root_owner = btrfs_header_owner(eb);
+        root_gen = btrfs_header_generation(eb);
+        sorted = kmalloc(sizeof(*sorted) * nritems, GFP_NOFS);
+
+        /*
+         * step one, sort all the leaf pointers so we don't scribble
+         * randomly into the extent allocation tree
+         */
+        for (i = slot; i < nritems; i++) {
+                sorted[refi].bytenr = btrfs_node_blockptr(eb, i);
+                sorted[refi].slot = i;
+                refi++;
+        }
+
+        /*
+         * nritems won't be zero, but if we're picking up drop_snapshot
+         * after a crash, slot might be > 0, so double check things
+         * just in case.
+         */
+        if (refi == 0)
+                goto out;
+
+        sort(sorted, refi, sizeof(struct refsort), refsort_cmp, NULL);
+
+        /*
+         * the first loop frees everything the leaves point to
+         */
+        for (i = 0; i < refi; i++) {
+                u64 ptr_gen;
+
+                bytenr = sorted[i].bytenr;
+
+                /*
+                 * check the reference count on this leaf.  If it is > 1
+                 * we just decrement it below and don't update any
+                 * of the refs the leaf points to.
+                 */
+                ret = drop_snap_lookup_refcount(root, bytenr, blocksize, &refs);
+                BUG_ON(ret);
+                if (refs != 1)
+                        continue;
+
+                ptr_gen = btrfs_node_ptr_generation(eb, sorted[i].slot);
+
+                /*
+                 * the leaf only had one reference, which means the
+                 * only thing pointing to this leaf is the snapshot
+                 * we're deleting.  It isn't possible for the reference
+                 * count to increase again later
+                 *
+                 * The reference cache is checked for the leaf,
+                 * and if found we'll be able to drop any refs held by
+                 * the leaf without needing to read it in.
+                 */
+                ref = btrfs_lookup_leaf_ref(root, bytenr);
+                if (ref && ref->generation != ptr_gen) {
+                        btrfs_free_leaf_ref(root, ref);
+                        ref = NULL;
+                }
+                if (ref) {
+                        ret = cache_drop_leaf_ref(trans, root, ref);
+                        BUG_ON(ret);
+                        btrfs_remove_leaf_ref(root, ref);
+                        btrfs_free_leaf_ref(root, ref);
+                } else {
+                        /*
+                         * the leaf wasn't in the reference cache, so
+                         * we have to read it.
+                         */
+                        leaf = read_tree_block(root, bytenr, blocksize,
+                                               ptr_gen);
+                        ret = btrfs_drop_leaf_ref(trans, root, leaf);
+                        BUG_ON(ret);
+                        free_extent_buffer(leaf);
+                }
+                atomic_inc(&root->fs_info->throttle_gen);
+                wake_up(&root->fs_info->transaction_throttle);
+                cond_resched();
+        }
+
+        /*
+         * run through the loop again to free the refs on the leaves.
+         * This is faster than doing it in the loop above because
+         * the leaves are likely to be clustered together.  We end up
+         * working in nice chunks on the extent allocation tree.
+         */
+        for (i = 0; i < refi; i++) {
+                bytenr = sorted[i].bytenr;
+                ret = __btrfs_free_extent(trans, root, bytenr,
+                                        blocksize, eb->start,
+                                        root_owner, root_gen, 0, 1);
+                BUG_ON(ret);
+
+                atomic_inc(&root->fs_info->throttle_gen);
+                wake_up(&root->fs_info->transaction_throttle);
+                cond_resched();
+        }
+out:
+        kfree(sorted);
+
+        /*
+         * update the path to show we've processed the entire level 1
+         * node.  This will get saved into the root's drop_snapshot_progress
+         * field so these drops are not repeated again if this transaction
+         * commits.
+         */
+        path->slots[1] = nritems;
+        return 0;
+}
+
+/*
  * helper function for drop_snapshot, this walks down the tree dropping ref
  * counts as it goes.
  */
@@ -3511,7 +3787,6 @@ static noinline int walk_down_tree(struct btrfs_trans_handle *trans,
         struct extent_buffer *next;
         struct extent_buffer *cur;
         struct extent_buffer *parent;
-        struct btrfs_leaf_ref *ref;
         u32 blocksize;
         int ret;
         u32 refs;
@@ -3538,17 +3813,46 @@ static noinline int walk_down_tree(struct btrfs_trans_handle *trans,
                 if (path->slots[*level] >=
                     btrfs_header_nritems(cur))
                         break;
+
+                /* the new code goes down to level 1 and does all the
+                 * leaves pointed to that node in bulk.  So, this check
+                 * for level 0 will always be false.
+                 *
+                 * But, the disk format allows the drop_snapshot_progress
+                 * field in the root to leave things in a state where
+                 * a leaf will need cleaning up here.  If someone crashes
+                 * with the old code and then boots with the new code,
+                 * we might find a leaf here.
+                 */
                 if (*level == 0) {
                         ret = btrfs_drop_leaf_ref(trans, root, cur);
                         BUG_ON(ret);
                         break;
                 }
+
+                /*
+                 * once we get to level one, process the whole node
+                 * at once, including everything below it.
+                 */
+                if (*level == 1) {
+                        ret = drop_level_one_refs(trans, root, path);
+                        BUG_ON(ret);
+                        break;
+                }
+
                 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
                 ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
                 blocksize = btrfs_level_size(root, *level - 1);
 
                 ret = drop_snap_lookup_refcount(root, bytenr, blocksize, &refs);
                 BUG_ON(ret);
+
+                /*
+                 * if there is more than one reference, we don't need
+                 * to read that node to drop any references it has.  We
+                 * just drop the ref we hold on that node and move on to the
+                 * next slot in this level.
+                 */
                 if (refs != 1) {
                         parent = path->nodes[*level];
                         root_owner = btrfs_header_owner(parent);
@@ -3567,46 +3871,12 @@ static noinline int walk_down_tree(struct btrfs_trans_handle *trans,
 
                         continue;
                 }
+
                 /*
-                 * at this point, we have a single ref, and since the
-                 * only place referencing this extent is a dead root
-                 * the reference count should never go higher.
-                 * So, we don't need to check it again
+                 * we need to keep freeing things in the next level down.
+                 * read the block and loop around to process it
                  */
-                if (*level == 1) {
-                        ref = btrfs_lookup_leaf_ref(root, bytenr);
-                        if (ref && ref->generation != ptr_gen) {
-                                btrfs_free_leaf_ref(root, ref);
-                                ref = NULL;
-                        }
-                        if (ref) {
-                                ret = cache_drop_leaf_ref(trans, root, ref);
-                                BUG_ON(ret);
-                                btrfs_remove_leaf_ref(root, ref);
-                                btrfs_free_leaf_ref(root, ref);
-                                *level = 0;
-                                break;
-                        }
-                }
-                next = btrfs_find_tree_block(root, bytenr, blocksize);
-                if (!next || !btrfs_buffer_uptodate(next, ptr_gen)) {
-                        free_extent_buffer(next);
-
-                        next = read_tree_block(root, bytenr, blocksize,
-                                               ptr_gen);
-                        cond_resched();
-#if 0
-                        /*
-                         * this is a debugging check and can go away
-                         * the ref should never go all the way down to 1
-                         * at this point
-                         */
-                        ret = lookup_extent_ref(NULL, root, bytenr, blocksize,
-                                                &refs);
-                        BUG_ON(ret);
-                        WARN_ON(refs != 1);
-#endif
-                }
+                next = read_tree_block(root, bytenr, blocksize, ptr_gen);
                 WARN_ON(*level <= 0);
                 if (path->nodes[*level-1])
                         free_extent_buffer(path->nodes[*level-1]);
@@ -3631,11 +3901,16 @@ out:
         root_owner = btrfs_header_owner(parent);
         root_gen = btrfs_header_generation(parent);
 
+        /*
+         * cleanup and free the reference on the last node
+         * we processed
+         */
         ret = __btrfs_free_extent(trans, root, bytenr, blocksize,
                                   parent->start, root_owner, root_gen,
                                   *level, 1);
         free_extent_buffer(path->nodes[*level]);
         path->nodes[*level] = NULL;
+
         *level += 1;
         BUG_ON(ret);
 
@@ -3687,6 +3962,7 @@ static noinline int walk_down_subtree(struct btrfs_trans_handle *trans,
 
                 next = read_tree_block(root, bytenr, blocksize, ptr_gen);
                 btrfs_tree_lock(next);
+                btrfs_set_lock_blocking(next);
 
                 ret = btrfs_lookup_extent_ref(trans, root, bytenr, blocksize,
                                               &refs);
@@ -3754,6 +4030,13 @@ static noinline int walk_up_tree(struct btrfs_trans_handle *trans,
                 if (slot < btrfs_header_nritems(path->nodes[i]) - 1) {
                         struct extent_buffer *node;
                         struct btrfs_disk_key disk_key;
+
+                        /*
+                         * there is more work to do in this level.
+                         * Update the drop_progress marker to reflect
+                         * the work we've done so far, and then bump
+                         * the slot number
+                         */
                         node = path->nodes[i];
                         path->slots[i]++;
                         *level = i;
@@ -3765,6 +4048,11 @@ static noinline int walk_up_tree(struct btrfs_trans_handle *trans,
                         return 0;
                 } else {
                         struct extent_buffer *parent;
+
+                        /*
+                         * this whole node is done, free our reference
+                         * on it and go up one level
+                         */
                         if (path->nodes[*level] == root->node)
                                 parent = path->nodes[*level];
                         else
@@ -4444,7 +4732,7 @@ static noinline int replace_one_extent(struct btrfs_trans_handle *trans,
         u64 lock_end = 0;
         u64 num_bytes;
         u64 ext_offset;
-        u64 first_pos;
+        u64 search_end = (u64)-1;
         u32 nritems;
         int nr_scaned = 0;
         int extent_locked = 0;
@@ -4452,7 +4740,6 @@ static noinline int replace_one_extent(struct btrfs_trans_handle *trans,
         int ret;
 
         memcpy(&key, leaf_key, sizeof(key));
-        first_pos = INT_LIMIT(loff_t) - extent_key->offset;
         if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) {
                 if (key.objectid < ref_path->owner_objectid ||
                     (key.objectid == ref_path->owner_objectid &&
@@ -4501,7 +4788,7 @@ next:
                         if ((key.objectid > ref_path->owner_objectid) ||
                             (key.objectid == ref_path->owner_objectid &&
                              key.type > BTRFS_EXTENT_DATA_KEY) ||
-                            (key.offset >= first_pos + extent_key->offset))
+                            key.offset >= search_end)
                                 break;
                 }
 
@@ -4534,8 +4821,10 @@ next:
                 num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
                 ext_offset = btrfs_file_extent_offset(leaf, fi);
 
-                if (first_pos > key.offset - ext_offset)
-                        first_pos = key.offset - ext_offset;
+                if (search_end == (u64)-1) {
+                        search_end = key.offset - ext_offset +
+                                btrfs_file_extent_ram_bytes(leaf, fi);
+                }
 
                 if (!extent_locked) {
                         lock_start = key.offset;
@@ -4724,7 +5013,7 @@ next:
                 }
 skip:
                 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS &&
-                    key.offset >= first_pos + extent_key->offset)
+                    key.offset >= search_end)
                         break;
 
                 cond_resched();
@@ -4778,6 +5067,7 @@ int btrfs_reloc_tree_cache_ref(struct btrfs_trans_handle *trans,
                 ref->bytenr = buf->start;
                 ref->owner = btrfs_header_owner(buf);
                 ref->generation = btrfs_header_generation(buf);
+
                 ret = btrfs_add_leaf_ref(root, ref, 0);
                 WARN_ON(ret);
                 btrfs_free_leaf_ref(root, ref);
@@ -5957,9 +6247,11 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
         path = btrfs_alloc_path();
         BUG_ON(!path);
 
-        btrfs_remove_free_space_cache(block_group);
+        spin_lock(&root->fs_info->block_group_cache_lock);
         rb_erase(&block_group->cache_node,
                  &root->fs_info->block_group_cache_tree);
+        spin_unlock(&root->fs_info->block_group_cache_lock);
+        btrfs_remove_free_space_cache(block_group);
         down_write(&block_group->space_info->groups_sem);
         list_del(&block_group->list);
         up_write(&block_group->space_info->groups_sem);
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index e086d407f1fa..37d43b516b79 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -9,7 +9,6 @@
 #include <linux/spinlock.h>
 #include <linux/blkdev.h>
 #include <linux/swap.h>
-#include <linux/version.h>
 #include <linux/writeback.h>
 #include <linux/pagevec.h>
 #include "extent_io.h"
@@ -31,7 +30,7 @@ static LIST_HEAD(buffers);
 static LIST_HEAD(states);
 
 #define LEAK_DEBUG 0
-#ifdef LEAK_DEBUG
+#if LEAK_DEBUG
 static DEFINE_SPINLOCK(leak_lock);
 #endif
 
@@ -120,7 +119,7 @@ void extent_io_tree_init(struct extent_io_tree *tree,
 static struct extent_state *alloc_extent_state(gfp_t mask)
 {
         struct extent_state *state;
-#ifdef LEAK_DEBUG
+#if LEAK_DEBUG
         unsigned long flags;
 #endif
 
@@ -130,7 +129,7 @@ static struct extent_state *alloc_extent_state(gfp_t mask)
         state->state = 0;
         state->private = 0;
         state->tree = NULL;
-#ifdef LEAK_DEBUG
+#if LEAK_DEBUG
         spin_lock_irqsave(&leak_lock, flags);
         list_add(&state->leak_list, &states);
         spin_unlock_irqrestore(&leak_lock, flags);
@@ -145,11 +144,11 @@ static void free_extent_state(struct extent_state *state)
         if (!state)
                 return;
         if (atomic_dec_and_test(&state->refs)) {
-#ifdef LEAK_DEBUG
+#if LEAK_DEBUG
                 unsigned long flags;
 #endif
                 WARN_ON(state->tree);
-#ifdef LEAK_DEBUG
+#if LEAK_DEBUG
                 spin_lock_irqsave(&leak_lock, flags);
                 list_del(&state->leak_list);
                 spin_unlock_irqrestore(&leak_lock, flags);
@@ -2378,11 +2377,6 @@ static int extent_write_cache_pages(struct extent_io_tree *tree,
         int scanned = 0;
         int range_whole = 0;
 
-        if (wbc->nonblocking && bdi_write_congested(bdi)) {
-                wbc->encountered_congestion = 1;
-                return 0;
-        }
-
         pagevec_init(&pvec, 0);
         if (wbc->range_cyclic) {
                 index = mapping->writeback_index; /* Start from prev offset */
@@ -2855,6 +2849,98 @@ out:
         return sector;
 }
 
+int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
+                __u64 start, __u64 len, get_extent_t *get_extent)
+{
+        int ret;
+        u64 off = start;
+        u64 max = start + len;
+        u32 flags = 0;
+        u64 disko = 0;
+        struct extent_map *em = NULL;
+        int end = 0;
+        u64 em_start = 0, em_len = 0;
+        unsigned long emflags;
+        ret = 0;
+
+        if (len == 0)
+                return -EINVAL;
+
+        lock_extent(&BTRFS_I(inode)->io_tree, start, start + len,
+                GFP_NOFS);
+        em = get_extent(inode, NULL, 0, off, max - off, 0);
+        if (!em)
+                goto out;
+        if (IS_ERR(em)) {
+                ret = PTR_ERR(em);
+                goto out;
+        }
+        while (!end) {
+                off = em->start + em->len;
+                if (off >= max)
+                        end = 1;
+
+                em_start = em->start;
+                em_len = em->len;
+
+                disko = 0;
+                flags = 0;
+
+                switch (em->block_start) {
+                case EXTENT_MAP_LAST_BYTE:
+                        end = 1;
+                        flags |= FIEMAP_EXTENT_LAST;
+                        break;
+                case EXTENT_MAP_HOLE:
+                        flags |= FIEMAP_EXTENT_UNWRITTEN;
+                        break;
+                case EXTENT_MAP_INLINE:
+                        flags |= (FIEMAP_EXTENT_DATA_INLINE |
+                                  FIEMAP_EXTENT_NOT_ALIGNED);
+                        break;
+                case EXTENT_MAP_DELALLOC:
+                        flags |= (FIEMAP_EXTENT_DELALLOC |
+                                  FIEMAP_EXTENT_UNKNOWN);
+                        break;
+                default:
+                        disko = em->block_start;
+                        break;
+                }
+                if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
+                        flags |= FIEMAP_EXTENT_ENCODED;
+
+                emflags = em->flags;
+                free_extent_map(em);
+                em = NULL;
+
+                if (!end) {
+                        em = get_extent(inode, NULL, 0, off, max - off, 0);
+                        if (!em)
+                                goto out;
+                        if (IS_ERR(em)) {
+                                ret = PTR_ERR(em);
+                                goto out;
+                        }
+                        emflags = em->flags;
+                }
+                if (test_bit(EXTENT_FLAG_VACANCY, &emflags)) {
+                        flags |= FIEMAP_EXTENT_LAST;
+                        end = 1;
+                }
+
+                ret = fiemap_fill_next_extent(fieinfo, em_start, disko,
+                                        em_len, flags);
+                if (ret)
+                        goto out_free;
+        }
+out_free:
+        free_extent_map(em);
+out:
+        unlock_extent(&BTRFS_I(inode)->io_tree, start, start + len,
+                        GFP_NOFS);
+        return ret;
+}
+
 static inline struct page *extent_buffer_page(struct extent_buffer *eb,
                                               unsigned long i)
 {
@@ -2892,15 +2978,17 @@ static struct extent_buffer *__alloc_extent_buffer(struct extent_io_tree *tree,
                                                    gfp_t mask)
 {
         struct extent_buffer *eb = NULL;
-#ifdef LEAK_DEBUG
+#if LEAK_DEBUG
         unsigned long flags;
 #endif
 
         eb = kmem_cache_zalloc(extent_buffer_cache, mask);
         eb->start = start;
         eb->len = len;
-        mutex_init(&eb->mutex);
-#ifdef LEAK_DEBUG
+        spin_lock_init(&eb->lock);
+        init_waitqueue_head(&eb->lock_wq);
+
+#if LEAK_DEBUG
         spin_lock_irqsave(&leak_lock, flags);
         list_add(&eb->leak_list, &buffers);
         spin_unlock_irqrestore(&leak_lock, flags);
@@ -2912,7 +3000,7 @@ static struct extent_buffer *__alloc_extent_buffer(struct extent_io_tree *tree,
 
 static void __free_extent_buffer(struct extent_buffer *eb)
 {
-#ifdef LEAK_DEBUG
+#if LEAK_DEBUG
         unsigned long flags;
         spin_lock_irqsave(&leak_lock, flags);
         list_del(&eb->leak_list);
@@ -2980,8 +3068,7 @@ struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree,
                 unlock_page(p);
         }
         if (uptodate)
-                eb->flags |= EXTENT_UPTODATE;
-        eb->flags |= EXTENT_BUFFER_FILLED;
+                set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
 
         spin_lock(&tree->buffer_lock);
         exists = buffer_tree_insert(tree, start, &eb->rb_node);
@@ -3135,7 +3222,7 @@ int clear_extent_buffer_uptodate(struct extent_io_tree *tree,
         unsigned long num_pages;
 
         num_pages = num_extent_pages(eb->start, eb->len);
-        eb->flags &= ~EXTENT_UPTODATE;
+        clear_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
 
         clear_extent_uptodate(tree, eb->start, eb->start + eb->len - 1,
                               GFP_NOFS);
@@ -3206,7 +3293,7 @@ int extent_buffer_uptodate(struct extent_io_tree *tree,
         struct page *page;
         int pg_uptodate = 1;
 
-        if (eb->flags & EXTENT_UPTODATE)
+        if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
                 return 1;
 
         ret = test_range_bit(tree, eb->start, eb->start + eb->len - 1,
@@ -3242,7 +3329,7 @@ int read_extent_buffer_pages(struct extent_io_tree *tree,
         struct bio *bio = NULL;
         unsigned long bio_flags = 0;
 
-        if (eb->flags & EXTENT_UPTODATE)
+        if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
                 return 0;
 
         if (test_range_bit(tree, eb->start, eb->start + eb->len - 1,
@@ -3273,7 +3360,7 @@ int read_extent_buffer_pages(struct extent_io_tree *tree,
         }
         if (all_uptodate) {
                 if (start_i == 0)
-                        eb->flags |= EXTENT_UPTODATE;
+                        set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
                 goto unlock_exit;
         }
 
@@ -3309,7 +3396,7 @@ int read_extent_buffer_pages(struct extent_io_tree *tree,
         }
 
         if (!ret)
-                eb->flags |= EXTENT_UPTODATE;
+                set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
         return ret;
 
 unlock_exit:
@@ -3406,7 +3493,6 @@ int map_extent_buffer(struct extent_buffer *eb, unsigned long start,
                 unmap_extent_buffer(eb, eb->map_token, km);
                 eb->map_token = NULL;
                 save = 1;
-                WARN_ON(!mutex_is_locked(&eb->mutex));
         }
         err = map_private_extent_buffer(eb, start, min_len, token, map,
                                        map_start, map_len, km);
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index c5b483a79137..1f9df88afbf6 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -22,6 +22,10 @@
 /* flags for bio submission */
 #define EXTENT_BIO_COMPRESSED 1
 
+/* these are bit numbers for test/set bit */
+#define EXTENT_BUFFER_UPTODATE 0
+#define EXTENT_BUFFER_BLOCKING 1
+
 /*
  * page->private values.  Every page that is controlled by the extent
  * map has page->private set to one.
@@ -95,11 +99,19 @@ struct extent_buffer {
         unsigned long map_start;
         unsigned long map_len;
         struct page *first_page;
+        unsigned long bflags;
         atomic_t refs;
-        int flags;
         struct list_head leak_list;
         struct rb_node rb_node;
-        struct mutex mutex;
+
+        /* the spinlock is used to protect most operations */
+        spinlock_t lock;
+
+        /*
+         * when we keep the lock held while blocking, waiters go onto
+         * the wq
+         */
+        wait_queue_head_t lock_wq;
 };
 
 struct extent_map_tree;
@@ -193,6 +205,8 @@ int extent_commit_write(struct extent_io_tree *tree,
                         unsigned from, unsigned to);
 sector_t extent_bmap(struct address_space *mapping, sector_t iblock,
                 get_extent_t *get_extent);
+int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
+                __u64 start, __u64 len, get_extent_t *get_extent);
 int set_range_dirty(struct extent_io_tree *tree, u64 start, u64 end);
 int set_state_private(struct extent_io_tree *tree, u64 start, u64 private);
 int get_state_private(struct extent_io_tree *tree, u64 start, u64 *private);
diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index 4a83e33ada32..50da69da20ce 100644
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -3,7 +3,6 @@
 #include <linux/slab.h>
 #include <linux/module.h>
 #include <linux/spinlock.h>
-#include <linux/version.h>
 #include <linux/hardirq.h>
 #include "extent_map.h"
 
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 90268334145e..3e8023efaff7 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -29,7 +29,6 @@
 #include <linux/writeback.h>
 #include <linux/statfs.h>
 #include <linux/compat.h>
-#include <linux/version.h>
 #include "ctree.h"
 #include "disk-io.h"
 #include "transaction.h"
@@ -1215,10 +1214,10 @@ int btrfs_sync_file(struct file *file, struct dentry *dentry, int datasync)
         }
         mutex_unlock(&root->fs_info->trans_mutex);
 
-        root->fs_info->tree_log_batch++;
+        root->log_batch++;
         filemap_fdatawrite(inode->i_mapping);
         btrfs_wait_ordered_range(inode, 0, (u64)-1);
-        root->fs_info->tree_log_batch++;
+        root->log_batch++;
 
         /*
          * ok we haven't committed the transaction yet, lets do a commit
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 8adfe059ab41..8f0706210a47 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -34,7 +34,6 @@
 #include <linux/statfs.h>
 #include <linux/compat.h>
 #include <linux/bit_spinlock.h>
-#include <linux/version.h>
 #include <linux/xattr.h>
 #include <linux/posix_acl.h>
 #include <linux/falloc.h>
@@ -51,6 +50,7 @@
 #include "tree-log.h"
 #include "ref-cache.h"
 #include "compression.h"
+#include "locking.h"
 
 struct btrfs_iget_args {
         u64 ino;
@@ -91,6 +91,16 @@ static noinline int cow_file_range(struct inode *inode,
                                    u64 start, u64 end, int *page_started,
                                    unsigned long *nr_written, int unlock);
 
+static int btrfs_init_inode_security(struct inode *inode,  struct inode *dir)
+{
+        int err;
+
+        err = btrfs_init_acl(inode, dir);
+        if (!err)
+                err = btrfs_xattr_security_init(inode, dir);
+        return err;
+}
+
 /*
  * a very lame attempt at stopping writes when the FS is 85% full.  There
  * are countless ways this is incorrect, but it is better than nothing.
@@ -350,6 +360,19 @@ again:
         nr_pages = (end >> PAGE_CACHE_SHIFT) - (start >> PAGE_CACHE_SHIFT) + 1;
         nr_pages = min(nr_pages, (128 * 1024UL) / PAGE_CACHE_SIZE);
 
+        /*
+         * we don't want to send crud past the end of i_size through
+         * compression, that's just a waste of CPU time.  So, if the
+         * end of the file is before the start of our current
+         * requested range of bytes, we bail out to the uncompressed
+         * cleanup code that can deal with all of this.
+         *
+         * It isn't really the fastest way to fix things, but this is a
+         * very uncommon corner.
+         */
+        if (actual_end <= start)
+                goto cleanup_and_bail_uncompressed;
+
         total_compressed = actual_end - start;
 
         /* we want to make sure that amount of ram required to uncompress
@@ -494,6 +517,7 @@ again:
                         goto again;
                 }
         } else {
+cleanup_and_bail_uncompressed:
                 /*
                  * No compression, but we still need to write the pages in
                  * the file we've been given so far.  redirty the locked
@@ -1324,12 +1348,11 @@ static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
                              struct inode *inode, u64 file_offset,
                              struct list_head *list)
 {
-        struct list_head *cur;
         struct btrfs_ordered_sum *sum;
 
         btrfs_set_trans_block_group(trans, inode);
-        list_for_each(cur, list) {
-                sum = list_entry(cur, struct btrfs_ordered_sum, list);
+
+        list_for_each_entry(sum, list, list) {
                 btrfs_csum_file_blocks(trans,
                        BTRFS_I(inode)->root->fs_info->csum_root, sum);
         }
@@ -2013,6 +2036,7 @@ void btrfs_read_locked_inode(struct inode *inode)
         BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
 
         alloc_group_block = btrfs_inode_block_group(leaf, inode_item);
+
         BTRFS_I(inode)->block_group = btrfs_find_block_group(root, 0,
                                                 alloc_group_block, 0);
         btrfs_free_path(path);
@@ -2039,6 +2063,7 @@ void btrfs_read_locked_inode(struct inode *inode)
                 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
                 break;
         default:
+                inode->i_op = &btrfs_special_inode_operations;
                 init_special_inode(inode, inode->i_mode, rdev);
                 break;
         }
@@ -2108,6 +2133,7 @@ noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
                 goto failed;
         }
 
+        btrfs_unlock_up_safe(path, 1);
         leaf = path->nodes[0];
         inode_item = btrfs_item_ptr(leaf, path->slots[0],
                                   struct btrfs_inode_item);
@@ -2429,6 +2455,8 @@ next_node:
                         ref->generation = leaf_gen;
                         ref->nritems = 0;
 
+                        btrfs_sort_leaf_ref(ref);
+
                         ret = btrfs_add_leaf_ref(root, ref, 0);
                         WARN_ON(ret);
                         btrfs_free_leaf_ref(root, ref);
@@ -2476,7 +2504,7 @@ noinline int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
         struct btrfs_path *path;
         struct btrfs_key key;
         struct btrfs_key found_key;
-        u32 found_type;
+        u32 found_type = (u8)-1;
         struct extent_buffer *leaf;
         struct btrfs_file_extent_item *fi;
         u64 extent_start = 0;
@@ -2663,6 +2691,8 @@ next:
                         if (pending_del_nr)
                                 goto del_pending;
                         btrfs_release_path(root, path);
+                        if (found_type == BTRFS_INODE_ITEM_KEY)
+                                break;
                         goto search_again;
                 }
 
@@ -2679,6 +2709,8 @@ del_pending:
                         BUG_ON(ret);
                         pending_del_nr = 0;
                         btrfs_release_path(root, path);
+                        if (found_type == BTRFS_INODE_ITEM_KEY)
+                                break;
                         goto search_again;
                 }
         }
@@ -3265,7 +3297,7 @@ skip:
 
         /* Reached end of directory/root. Bump pos past the last item. */
         if (key_type == BTRFS_DIR_INDEX_KEY)
-                filp->f_pos = INT_LIMIT(typeof(filp->f_pos));
+                filp->f_pos = INT_LIMIT(off_t);
         else
                 filp->f_pos++;
 nopos:
@@ -3458,7 +3490,14 @@ static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
                 root->highest_inode = objectid;
 
         inode->i_uid = current_fsuid();
-        inode->i_gid = current_fsgid();
+
+        if (dir && (dir->i_mode & S_ISGID)) {
+                inode->i_gid = dir->i_gid;
+                if (S_ISDIR(mode))
+                        mode |= S_ISGID;
+        } else
+                inode->i_gid = current_fsgid();
+
         inode->i_mode = mode;
         inode->i_ino = objectid;
         inode_set_bytes(inode, 0);
@@ -3586,7 +3625,7 @@ static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
         if (IS_ERR(inode))
                 goto out_unlock;
 
-        err = btrfs_init_acl(inode, dir);
+        err = btrfs_init_inode_security(inode, dir);
         if (err) {
                 drop_inode = 1;
                 goto out_unlock;
@@ -3649,7 +3688,7 @@ static int btrfs_create(struct inode *dir, struct dentry *dentry,
         if (IS_ERR(inode))
                 goto out_unlock;
 
-        err = btrfs_init_acl(inode, dir);
+        err = btrfs_init_inode_security(inode, dir);
         if (err) {
                 drop_inode = 1;
                 goto out_unlock;
@@ -3772,7 +3811,7 @@ static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 
         drop_on_err = 1;
 
-        err = btrfs_init_acl(inode, dir);
+        err = btrfs_init_inode_security(inode, dir);
         if (err)
                 goto out_fail;
 
@@ -4158,9 +4197,10 @@ static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb,
         return -EINVAL;
 }
 
-static sector_t btrfs_bmap(struct address_space *mapping, sector_t iblock)
+static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
+                __u64 start, __u64 len)
 {
-        return extent_bmap(mapping, iblock, btrfs_get_extent);
+        return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent);
 }
 
 int btrfs_readpage(struct file *file, struct page *page)
@@ -4733,7 +4773,7 @@ static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
         if (IS_ERR(inode))
                 goto out_unlock;
 
-        err = btrfs_init_acl(inode, dir);
+        err = btrfs_init_inode_security(inode, dir);
         if (err) {
                 drop_inode = 1;
                 goto out_unlock;
@@ -4987,13 +5027,24 @@ static struct extent_io_ops btrfs_extent_io_ops = {
         .clear_bit_hook = btrfs_clear_bit_hook,
 };
 
+/*
+ * btrfs doesn't support the bmap operation because swapfiles
+ * use bmap to make a mapping of extents in the file.  They assume
+ * these extents won't change over the life of the file and they
+ * use the bmap result to do IO directly to the drive.
+ *
+ * the btrfs bmap call would return logical addresses that aren't
+ * suitable for IO and they also will change frequently as COW
+ * operations happen.  So, swapfile + btrfs == corruption.
+ *
+ * For now we're avoiding this by dropping bmap.
+ */
 static struct address_space_operations btrfs_aops = {
         .readpage       = btrfs_readpage,
         .writepage      = btrfs_writepage,
         .writepages     = btrfs_writepages,
         .readpages      = btrfs_readpages,
         .sync_page      = block_sync_page,
-        .bmap           = btrfs_bmap,
         .direct_IO      = btrfs_direct_IO,
         .invalidatepage = btrfs_invalidatepage,
         .releasepage    = btrfs_releasepage,
@@ -5017,6 +5068,7 @@ static struct inode_operations btrfs_file_inode_operations = {
         .removexattr    = btrfs_removexattr,
         .permission     = btrfs_permission,
         .fallocate      = btrfs_fallocate,
+        .fiemap         = btrfs_fiemap,
 };
 static struct inode_operations btrfs_special_inode_operations = {
         .getattr        = btrfs_getattr,
@@ -5032,4 +5084,8 @@ static struct inode_operations btrfs_symlink_inode_operations = {
         .follow_link    = page_follow_link_light,
         .put_link       = page_put_link,
         .permission     = btrfs_permission,
+        .setxattr       = btrfs_setxattr,
+        .getxattr       = btrfs_getxattr,
+        .listxattr      = btrfs_listxattr,
+        .removexattr    = btrfs_removexattr,
 };
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index c2aa33e3feb5..988fdc8b49eb 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -38,7 +38,6 @@
 #include <linux/compat.h>
 #include <linux/bit_spinlock.h>
 #include <linux/security.h>
-#include <linux/version.h>
 #include <linux/xattr.h>
 #include <linux/vmalloc.h>
 #include "compat.h"
diff --git a/fs/btrfs/locking.c b/fs/btrfs/locking.c
index 39bae7761db6..9ebe9385129b 100644
--- a/fs/btrfs/locking.c
+++ b/fs/btrfs/locking.c
@@ -26,63 +26,213 @@
 #include "locking.h"
 
 /*
- * locks the per buffer mutex in an extent buffer.  This uses adaptive locks
- * and the spin is not tuned very extensively.  The spinning does make a big
- * difference in almost every workload, but spinning for the right amount of
- * time needs some help.
- *
- * In general, we want to spin as long as the lock holder is doing btree
- * searches, and we should give up if they are in more expensive code.
+ * btrfs_header_level() isn't free, so don't call it when lockdep isn't
+ * on
  */
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+static inline void spin_nested(struct extent_buffer *eb)
+{
+        spin_lock_nested(&eb->lock, BTRFS_MAX_LEVEL - btrfs_header_level(eb));
+}
+#else
+static inline void spin_nested(struct extent_buffer *eb)
+{
+        spin_lock(&eb->lock);
+}
+#endif
 
-int btrfs_tree_lock(struct extent_buffer *eb)
+/*
+ * Setting a lock to blocking will drop the spinlock and set the
+ * flag that forces other procs who want the lock to wait.  After
+ * this you can safely schedule with the lock held.
+ */
+void btrfs_set_lock_blocking(struct extent_buffer *eb)
 {
-        int i;
+        if (!test_bit(EXTENT_BUFFER_BLOCKING, &eb->bflags)) {
+                set_bit(EXTENT_BUFFER_BLOCKING, &eb->bflags);
+                spin_unlock(&eb->lock);
+        }
+        /* exit with the spin lock released and the bit set */
+}
 
-        if (mutex_trylock(&eb->mutex))
-                return 0;
+/*
+ * clearing the blocking flag will take the spinlock again.
+ * After this you can't safely schedule
+ */
+void btrfs_clear_lock_blocking(struct extent_buffer *eb)
+{
+        if (test_bit(EXTENT_BUFFER_BLOCKING, &eb->bflags)) {
+                spin_nested(eb);
+                clear_bit(EXTENT_BUFFER_BLOCKING, &eb->bflags);
+                smp_mb__after_clear_bit();
+        }
+        /* exit with the spin lock held */
+}
+
+/*
+ * unfortunately, many of the places that currently set a lock to blocking
+ * don't end up blocking for every long, and often they don't block
+ * at all.  For a dbench 50 run, if we don't spin one the blocking bit
+ * at all, the context switch rate can jump up to 400,000/sec or more.
+ *
+ * So, we're still stuck with this crummy spin on the blocking bit,
+ * at least until the most common causes of the short blocks
+ * can be dealt with.
+ */
+static int btrfs_spin_on_block(struct extent_buffer *eb)
+{
+        int i;
         for (i = 0; i < 512; i++) {
                 cpu_relax();
-                if (mutex_trylock(&eb->mutex))
-                        return 0;
+                if (!test_bit(EXTENT_BUFFER_BLOCKING, &eb->bflags))
+                        return 1;
+                if (need_resched())
+                        break;
         }
-        cpu_relax();
-        mutex_lock_nested(&eb->mutex, BTRFS_MAX_LEVEL - btrfs_header_level(eb));
         return 0;
 }
 
-int btrfs_try_tree_lock(struct extent_buffer *eb)
+/*
+ * This is somewhat different from trylock.  It will take the
+ * spinlock but if it finds the lock is set to blocking, it will
+ * return without the lock held.
+ *
+ * returns 1 if it was able to take the lock and zero otherwise
+ *
+ * After this call, scheduling is not safe without first calling
+ * btrfs_set_lock_blocking()
+ */
+int btrfs_try_spin_lock(struct extent_buffer *eb)
 {
-        return mutex_trylock(&eb->mutex);
+        int i;
+
+        spin_nested(eb);
+        if (!test_bit(EXTENT_BUFFER_BLOCKING, &eb->bflags))
+                return 1;
+        spin_unlock(&eb->lock);
+
+        /* spin for a bit on the BLOCKING flag */
+        for (i = 0; i < 2; i++) {
+                if (!btrfs_spin_on_block(eb))
+                        break;
+
+                spin_nested(eb);
+                if (!test_bit(EXTENT_BUFFER_BLOCKING, &eb->bflags))
+                        return 1;
+                spin_unlock(&eb->lock);
+        }
+        return 0;
 }
 
-int btrfs_tree_unlock(struct extent_buffer *eb)
+/*
+ * the autoremove wake function will return 0 if it tried to wake up
+ * a process that was already awake, which means that process won't
+ * count as an exclusive wakeup.  The waitq code will continue waking
+ * procs until it finds one that was actually sleeping.
+ *
+ * For btrfs, this isn't quite what we want.  We want a single proc
+ * to be notified that the lock is ready for taking.  If that proc
+ * already happen to be awake, great, it will loop around and try for
+ * the lock.
+ *
+ * So, btrfs_wake_function always returns 1, even when the proc that we
+ * tried to wake up was already awake.
+ */
+static int btrfs_wake_function(wait_queue_t *wait, unsigned mode,
+                               int sync, void *key)
 {
-        mutex_unlock(&eb->mutex);
-        return 0;
+        autoremove_wake_function(wait, mode, sync, key);
+        return 1;
 }
 
-int btrfs_tree_locked(struct extent_buffer *eb)
+/*
+ * returns with the extent buffer spinlocked.
+ *
+ * This will spin and/or wait as required to take the lock, and then
+ * return with the spinlock held.
+ *
+ * After this call, scheduling is not safe without first calling
+ * btrfs_set_lock_blocking()
+ */
+int btrfs_tree_lock(struct extent_buffer *eb)
 {
-        return mutex_is_locked(&eb->mutex);
+        DEFINE_WAIT(wait);
+        wait.func = btrfs_wake_function;
+
+        while(1) {
+                spin_nested(eb);
+
+                /* nobody is blocking, exit with the spinlock held */
+                if (!test_bit(EXTENT_BUFFER_BLOCKING, &eb->bflags))
+                        return 0;
+
+                /*
+                 * we have the spinlock, but the real owner is blocking.
+                 * wait for them
+                 */
+                spin_unlock(&eb->lock);
+
+                /*
+                 * spin for a bit, and if the blocking flag goes away,
+                 * loop around
+                 */
+                if (btrfs_spin_on_block(eb))
+                        continue;
+
+                prepare_to_wait_exclusive(&eb->lock_wq, &wait,
+                                          TASK_UNINTERRUPTIBLE);
+
+                if (test_bit(EXTENT_BUFFER_BLOCKING, &eb->bflags))
+                        schedule();
+
+                finish_wait(&eb->lock_wq, &wait);
+        }
+        return 0;
 }
 
 /*
- * btrfs_search_slot uses this to decide if it should drop its locks
- * before doing something expensive like allocating free blocks for cow.
+ * Very quick trylock, this does not spin or schedule.  It returns
+ * 1 with the spinlock held if it was able to take the lock, or it
+ * returns zero if it was unable to take the lock.
+ *
+ * After this call, scheduling is not safe without first calling
+ * btrfs_set_lock_blocking()
  */
-int btrfs_path_lock_waiting(struct btrfs_path *path, int level)
+int btrfs_try_tree_lock(struct extent_buffer *eb)
 {
-        int i;
-        struct extent_buffer *eb;
-        for (i = level; i <= level + 1 && i < BTRFS_MAX_LEVEL; i++) {
-                eb = path->nodes[i];
-                if (!eb)
-                        break;
-                smp_mb();
-                if (!list_empty(&eb->mutex.wait_list))
-                        return 1;
+        if (spin_trylock(&eb->lock)) {
+                if (test_bit(EXTENT_BUFFER_BLOCKING, &eb->bflags)) {
+                        /*
+                         * we've got the spinlock, but the real owner is
+                         * blocking.  Drop the spinlock and return failure
+                         */
+                        spin_unlock(&eb->lock);
+                        return 0;
+                }
+                return 1;
         }
+        /* someone else has the spinlock giveup */
         return 0;
 }
 
+int btrfs_tree_unlock(struct extent_buffer *eb)
+{
+        /*
+         * if we were a blocking owner, we don't have the spinlock held
+         * just clear the bit and look for waiters
+         */
+        if (test_and_clear_bit(EXTENT_BUFFER_BLOCKING, &eb->bflags))
+                smp_mb__after_clear_bit();
+        else
+                spin_unlock(&eb->lock);
+
+        if (waitqueue_active(&eb->lock_wq))
+                wake_up(&eb->lock_wq);
+        return 0;
+}
+
+int btrfs_tree_locked(struct extent_buffer *eb)
+{
+        return test_bit(EXTENT_BUFFER_BLOCKING, &eb->bflags) ||
+                        spin_is_locked(&eb->lock);
+}
diff --git a/fs/btrfs/locking.h b/fs/btrfs/locking.h
index bc1faef12519..6bb0afbff928 100644
--- a/fs/btrfs/locking.h
+++ b/fs/btrfs/locking.h
@@ -22,6 +22,10 @@
 int btrfs_tree_lock(struct extent_buffer *eb);
 int btrfs_tree_unlock(struct extent_buffer *eb);
 int btrfs_tree_locked(struct extent_buffer *eb);
+
 int btrfs_try_tree_lock(struct extent_buffer *eb);
-int btrfs_path_lock_waiting(struct btrfs_path *path, int level);
+int btrfs_try_spin_lock(struct extent_buffer *eb);
+
+void btrfs_set_lock_blocking(struct extent_buffer *eb);
+void btrfs_clear_lock_blocking(struct extent_buffer *eb);
 #endif
diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c
index a20940170274..77c2411a5f0f 100644
--- a/fs/btrfs/ordered-data.c
+++ b/fs/btrfs/ordered-data.c
@@ -613,7 +613,6 @@ int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr,
         struct btrfs_sector_sum *sector_sums;
         struct btrfs_ordered_extent *ordered;
         struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
-        struct list_head *cur;
         unsigned long num_sectors;
         unsigned long i;
         u32 sectorsize = BTRFS_I(inode)->root->sectorsize;
@@ -624,8 +623,7 @@ int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr,
                 return 1;
 
         mutex_lock(&tree->mutex);
-        list_for_each_prev(cur, &ordered->list) {
-                ordered_sum = list_entry(cur, struct btrfs_ordered_sum, list);
+        list_for_each_entry_reverse(ordered_sum, &ordered->list, list) {
                 if (disk_bytenr >= ordered_sum->bytenr) {
                         num_sectors = ordered_sum->len / sectorsize;
                         sector_sums = ordered_sum->sums;
diff --git a/fs/btrfs/ref-cache.c b/fs/btrfs/ref-cache.c
index 6f0acc4c9eab..d0cc62bccb94 100644
--- a/fs/btrfs/ref-cache.c
+++ b/fs/btrfs/ref-cache.c
@@ -17,6 +17,7 @@
  */
 
 #include <linux/sched.h>
+#include <linux/sort.h>
 #include "ctree.h"
 #include "ref-cache.h"
 #include "transaction.h"
diff --git a/fs/btrfs/ref-cache.h b/fs/btrfs/ref-cache.h
index 16f3183d7c59..bc283ad2db73 100644
--- a/fs/btrfs/ref-cache.h
+++ b/fs/btrfs/ref-cache.h
@@ -73,5 +73,4 @@ int btrfs_add_leaf_ref(struct btrfs_root *root, struct btrfs_leaf_ref *ref,
 int btrfs_remove_leaf_refs(struct btrfs_root *root, u64 max_root_gen,
                            int shared);
 int btrfs_remove_leaf_ref(struct btrfs_root *root, struct btrfs_leaf_ref *ref);
-
 #endif
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index db9fb3bc1e33..f3fd7e2cbc38 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -37,7 +37,6 @@
 #include <linux/ctype.h>
 #include <linux/namei.h>
 #include <linux/miscdevice.h>
-#include <linux/version.h>
 #include <linux/magic.h>
 #include "compat.h"
 #include "ctree.h"
@@ -583,17 +582,18 @@ static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
         struct btrfs_ioctl_vol_args *vol;
         struct btrfs_fs_devices *fs_devices;
         int ret = -ENOTTY;
-        int len;
 
         if (!capable(CAP_SYS_ADMIN))
                 return -EPERM;
 
         vol = kmalloc(sizeof(*vol), GFP_KERNEL);
+        if (!vol)
+                return -ENOMEM;
+
         if (copy_from_user(vol, (void __user *)arg, sizeof(*vol))) {
                 ret = -EFAULT;
                 goto out;
         }
-        len = strnlen(vol->name, BTRFS_PATH_NAME_MAX);
 
         switch (cmd) {
         case BTRFS_IOC_SCAN_DEV:
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 8a08f9443340..919172de5c9a 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -852,11 +852,9 @@ static noinline int create_pending_snapshots(struct btrfs_trans_handle *trans,
 {
         struct btrfs_pending_snapshot *pending;
         struct list_head *head = &trans->transaction->pending_snapshots;
-        struct list_head *cur;
         int ret;
 
-        list_for_each(cur, head) {
-                pending = list_entry(cur, struct btrfs_pending_snapshot, list);
+        list_for_each_entry(pending, head, list) {
                 ret = create_pending_snapshot(trans, fs_info, pending);
                 BUG_ON(ret);
         }
diff --git a/fs/btrfs/tree-defrag.c b/fs/btrfs/tree-defrag.c
index 3e8358c36165..98d25fa4570e 100644
--- a/fs/btrfs/tree-defrag.c
+++ b/fs/btrfs/tree-defrag.c
@@ -74,6 +74,7 @@ int btrfs_defrag_leaves(struct btrfs_trans_handle *trans,
                 u32 nritems;
 
                 root_node = btrfs_lock_root_node(root);
+                btrfs_set_lock_blocking(root_node);
                 nritems = btrfs_header_nritems(root_node);
                 root->defrag_max.objectid = 0;
                 /* from above we know this is not a leaf */
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index d81cda2e077c..20794290256b 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -78,104 +78,6 @@ static int link_to_fixup_dir(struct btrfs_trans_handle *trans,
  */
 
 /*
- * btrfs_add_log_tree adds a new per-subvolume log tree into the
- * tree of log tree roots.  This must be called with a tree log transaction
- * running (see start_log_trans).
- */
-static int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
-                      struct btrfs_root *root)
-{
-        struct btrfs_key key;
-        struct btrfs_root_item root_item;
-        struct btrfs_inode_item *inode_item;
-        struct extent_buffer *leaf;
-        struct btrfs_root *new_root = root;
-        int ret;
-        u64 objectid = root->root_key.objectid;
-
-        leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 0,
-                                      BTRFS_TREE_LOG_OBJECTID,
-                                      trans->transid, 0, 0, 0);
-        if (IS_ERR(leaf)) {
-                ret = PTR_ERR(leaf);
-                return ret;
-        }
-
-        btrfs_set_header_nritems(leaf, 0);
-        btrfs_set_header_level(leaf, 0);
-        btrfs_set_header_bytenr(leaf, leaf->start);
-        btrfs_set_header_generation(leaf, trans->transid);
-        btrfs_set_header_owner(leaf, BTRFS_TREE_LOG_OBJECTID);
-
-        write_extent_buffer(leaf, root->fs_info->fsid,
-                            (unsigned long)btrfs_header_fsid(leaf),
-                            BTRFS_FSID_SIZE);
-        btrfs_mark_buffer_dirty(leaf);
-
-        inode_item = &root_item.inode;
-        memset(inode_item, 0, sizeof(*inode_item));
-        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_bytenr(&root_item, leaf->start);
-        btrfs_set_root_generation(&root_item, trans->transid);
-        btrfs_set_root_level(&root_item, 0);
-        btrfs_set_root_refs(&root_item, 0);
-        btrfs_set_root_used(&root_item, 0);
-
-        memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
-        root_item.drop_level = 0;
-
-        btrfs_tree_unlock(leaf);
-        free_extent_buffer(leaf);
-        leaf = NULL;
-
-        btrfs_set_root_dirid(&root_item, 0);
-
-        key.objectid = BTRFS_TREE_LOG_OBJECTID;
-        key.offset = objectid;
-        btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
-        ret = btrfs_insert_root(trans, root->fs_info->log_root_tree, &key,
-                                &root_item);
-        if (ret)
-                goto fail;
-
-        new_root = btrfs_read_fs_root_no_radix(root->fs_info->log_root_tree,
-                                               &key);
-        BUG_ON(!new_root);
-
-        WARN_ON(root->log_root);
-        root->log_root = new_root;
-
-        /*
-         * 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).
-         */
-        new_root->ref_cows = 0;
-        new_root->last_trans = trans->transid;
-
-        /*
-         * we need to make sure the root block for this new tree
-         * is marked as dirty in the dirty_log_pages tree.  This
-         * is how it gets flushed down to disk at tree log commit time.
-         *
-         * the tree logging mutex keeps others from coming in and changing
-         * the new_root->node, so we can safely access it here
-         */
-        set_extent_dirty(&new_root->dirty_log_pages, new_root->node->start,
-                         new_root->node->start + new_root->node->len - 1,
-                         GFP_NOFS);
-
-fail:
-        return ret;
-}
-
-/*
  * start a sub transaction and setup the log tree
  * this increments the log tree writer count to make the people
  * syncing the tree wait for us to finish
@@ -184,6 +86,14 @@ static int start_log_trans(struct btrfs_trans_handle *trans,
                            struct btrfs_root *root)
 {
         int ret;
+
+        mutex_lock(&root->log_mutex);
+        if (root->log_root) {
+                root->log_batch++;
+                atomic_inc(&root->log_writers);
+                mutex_unlock(&root->log_mutex);
+                return 0;
+        }
         mutex_lock(&root->fs_info->tree_log_mutex);
         if (!root->fs_info->log_root_tree) {
                 ret = btrfs_init_log_root_tree(trans, root->fs_info);
@@ -193,9 +103,10 @@ static int start_log_trans(struct btrfs_trans_handle *trans,
                 ret = btrfs_add_log_tree(trans, root);
                 BUG_ON(ret);
         }
-        atomic_inc(&root->fs_info->tree_log_writers);
-        root->fs_info->tree_log_batch++;
         mutex_unlock(&root->fs_info->tree_log_mutex);
+        root->log_batch++;
+        atomic_inc(&root->log_writers);
+        mutex_unlock(&root->log_mutex);
         return 0;
 }
 
@@ -212,13 +123,12 @@ static int join_running_log_trans(struct btrfs_root *root)
         if (!root->log_root)
                 return -ENOENT;
 
-        mutex_lock(&root->fs_info->tree_log_mutex);
+        mutex_lock(&root->log_mutex);
         if (root->log_root) {
                 ret = 0;
-                atomic_inc(&root->fs_info->tree_log_writers);
-                root->fs_info->tree_log_batch++;
+                atomic_inc(&root->log_writers);
         }
-        mutex_unlock(&root->fs_info->tree_log_mutex);
+        mutex_unlock(&root->log_mutex);
         return ret;
 }
 
@@ -228,10 +138,11 @@ static int join_running_log_trans(struct btrfs_root *root)
  */
 static int end_log_trans(struct btrfs_root *root)
 {
-        atomic_dec(&root->fs_info->tree_log_writers);
-        smp_mb();
-        if (waitqueue_active(&root->fs_info->tree_log_wait))
-                wake_up(&root->fs_info->tree_log_wait);
+        if (atomic_dec_and_test(&root->log_writers)) {
+                smp_mb();
+                if (waitqueue_active(&root->log_writer_wait))
+                        wake_up(&root->log_writer_wait);
+        }
         return 0;
 }
 
@@ -1704,6 +1615,7 @@ static noinline int walk_down_log_tree(struct btrfs_trans_handle *trans,
 
                                 btrfs_tree_lock(next);
                                 clean_tree_block(trans, root, next);
+                                btrfs_set_lock_blocking(next);
                                 btrfs_wait_tree_block_writeback(next);
                                 btrfs_tree_unlock(next);
 
@@ -1750,6 +1662,7 @@ static noinline int walk_down_log_tree(struct btrfs_trans_handle *trans,
                 next = path->nodes[*level];
                 btrfs_tree_lock(next);
                 clean_tree_block(trans, root, next);
+                btrfs_set_lock_blocking(next);
                 btrfs_wait_tree_block_writeback(next);
                 btrfs_tree_unlock(next);
 
@@ -1807,6 +1720,7 @@ static noinline int walk_up_log_tree(struct btrfs_trans_handle *trans,
 
                                 btrfs_tree_lock(next);
                                 clean_tree_block(trans, root, next);
+                                btrfs_set_lock_blocking(next);
                                 btrfs_wait_tree_block_writeback(next);
                                 btrfs_tree_unlock(next);
 
@@ -1879,6 +1793,7 @@ static int walk_log_tree(struct btrfs_trans_handle *trans,
 
                         btrfs_tree_lock(next);
                         clean_tree_block(trans, log, next);
+                        btrfs_set_lock_blocking(next);
                         btrfs_wait_tree_block_writeback(next);
                         btrfs_tree_unlock(next);
 
@@ -1902,26 +1817,65 @@ static int walk_log_tree(struct btrfs_trans_handle *trans,
                 }
         }
         btrfs_free_path(path);
-        if (wc->free)
-                free_extent_buffer(log->node);
         return ret;
 }
 
-static int wait_log_commit(struct btrfs_root *log)
+/*
+ * helper function to update the item for a given subvolumes log root
+ * in the tree of log roots
+ */
+static int update_log_root(struct btrfs_trans_handle *trans,
+                           struct btrfs_root *log)
+{
+        int ret;
+
+        if (log->log_transid == 1) {
+                /* insert root item on the first sync */
+                ret = btrfs_insert_root(trans, log->fs_info->log_root_tree,
+                                &log->root_key, &log->root_item);
+        } else {
+                ret = btrfs_update_root(trans, log->fs_info->log_root_tree,
+                                &log->root_key, &log->root_item);
+        }
+        return ret;
+}
+
+static int wait_log_commit(struct btrfs_root *root, unsigned long transid)
 {
         DEFINE_WAIT(wait);
-        u64 transid = log->fs_info->tree_log_transid;
+        int index = transid % 2;
 
+        /*
+         * we only allow two pending log transactions at a time,
+         * so we know that if ours is more than 2 older than the
+         * current transaction, we're done
+         */
         do {
-                prepare_to_wait(&log->fs_info->tree_log_wait, &wait,
-                                TASK_UNINTERRUPTIBLE);
-                mutex_unlock(&log->fs_info->tree_log_mutex);
-                if (atomic_read(&log->fs_info->tree_log_commit))
+                prepare_to_wait(&root->log_commit_wait[index],
+                                &wait, TASK_UNINTERRUPTIBLE);
+                mutex_unlock(&root->log_mutex);
+                if (root->log_transid < transid + 2 &&
+                    atomic_read(&root->log_commit[index]))
                         schedule();
-                finish_wait(&log->fs_info->tree_log_wait, &wait);
-                mutex_lock(&log->fs_info->tree_log_mutex);
-        } while (transid == log->fs_info->tree_log_transid &&
-                atomic_read(&log->fs_info->tree_log_commit));
+                finish_wait(&root->log_commit_wait[index], &wait);
+                mutex_lock(&root->log_mutex);
+        } while (root->log_transid < transid + 2 &&
+                 atomic_read(&root->log_commit[index]));
+        return 0;
+}
+
+static int wait_for_writer(struct btrfs_root *root)
+{
+        DEFINE_WAIT(wait);
+        while (atomic_read(&root->log_writers)) {
+                prepare_to_wait(&root->log_writer_wait,
+                                &wait, TASK_UNINTERRUPTIBLE);
+                mutex_unlock(&root->log_mutex);
+                if (atomic_read(&root->log_writers))
+                        schedule();
+                mutex_lock(&root->log_mutex);
+                finish_wait(&root->log_writer_wait, &wait);
+        }
         return 0;
 }
 
@@ -1933,57 +1887,114 @@ static int wait_log_commit(struct btrfs_root *log)
 int btrfs_sync_log(struct btrfs_trans_handle *trans,
                    struct btrfs_root *root)
 {
+        int index1;
+        int index2;
         int ret;
-        unsigned long batch;
         struct btrfs_root *log = root->log_root;
+        struct btrfs_root *log_root_tree = root->fs_info->log_root_tree;
 
-        mutex_lock(&log->fs_info->tree_log_mutex);
-        if (atomic_read(&log->fs_info->tree_log_commit)) {
-                wait_log_commit(log);
-                goto out;
+        mutex_lock(&root->log_mutex);
+        index1 = root->log_transid % 2;
+        if (atomic_read(&root->log_commit[index1])) {
+                wait_log_commit(root, root->log_transid);
+                mutex_unlock(&root->log_mutex);
+                return 0;
         }
-        atomic_set(&log->fs_info->tree_log_commit, 1);
+        atomic_set(&root->log_commit[index1], 1);
+
+        /* wait for previous tree log sync to complete */
+        if (atomic_read(&root->log_commit[(index1 + 1) % 2]))
+                wait_log_commit(root, root->log_transid - 1);
 
         while (1) {
-                batch = log->fs_info->tree_log_batch;
-                mutex_unlock(&log->fs_info->tree_log_mutex);
+                unsigned long batch = root->log_batch;
+                mutex_unlock(&root->log_mutex);
                 schedule_timeout_uninterruptible(1);
-                mutex_lock(&log->fs_info->tree_log_mutex);
-
-                while (atomic_read(&log->fs_info->tree_log_writers)) {
-                        DEFINE_WAIT(wait);
-                        prepare_to_wait(&log->fs_info->tree_log_wait, &wait,
-                                        TASK_UNINTERRUPTIBLE);
-                        mutex_unlock(&log->fs_info->tree_log_mutex);
-                        if (atomic_read(&log->fs_info->tree_log_writers))
-                                schedule();
-                        mutex_lock(&log->fs_info->tree_log_mutex);
-                        finish_wait(&log->fs_info->tree_log_wait, &wait);
-                }
-                if (batch == log->fs_info->tree_log_batch)
+                mutex_lock(&root->log_mutex);
+                wait_for_writer(root);
+                if (batch == root->log_batch)
                         break;
         }
 
         ret = btrfs_write_and_wait_marked_extents(log, &log->dirty_log_pages);
         BUG_ON(ret);
-        ret = btrfs_write_and_wait_marked_extents(root->fs_info->log_root_tree,
-                               &root->fs_info->log_root_tree->dirty_log_pages);
+
+        btrfs_set_root_bytenr(&log->root_item, log->node->start);
+        btrfs_set_root_generation(&log->root_item, trans->transid);
+        btrfs_set_root_level(&log->root_item, btrfs_header_level(log->node));
+
+        root->log_batch = 0;
+        root->log_transid++;
+        log->log_transid = root->log_transid;
+        smp_mb();
+        /*
+         * log tree has been flushed to disk, new modifications of
+         * the log will be written to new positions. so it's safe to
+         * allow log writers to go in.
+         */
+        mutex_unlock(&root->log_mutex);
+
+        mutex_lock(&log_root_tree->log_mutex);
+        log_root_tree->log_batch++;
+        atomic_inc(&log_root_tree->log_writers);
+        mutex_unlock(&log_root_tree->log_mutex);
+
+        ret = update_log_root(trans, log);
+        BUG_ON(ret);
+
+        mutex_lock(&log_root_tree->log_mutex);
+        if (atomic_dec_and_test(&log_root_tree->log_writers)) {
+                smp_mb();
+                if (waitqueue_active(&log_root_tree->log_writer_wait))
+                        wake_up(&log_root_tree->log_writer_wait);
+        }
+
+        index2 = log_root_tree->log_transid % 2;
+        if (atomic_read(&log_root_tree->log_commit[index2])) {
+                wait_log_commit(log_root_tree, log_root_tree->log_transid);
+                mutex_unlock(&log_root_tree->log_mutex);
+                goto out;
+        }
+        atomic_set(&log_root_tree->log_commit[index2], 1);
+
+        if (atomic_read(&log_root_tree->log_commit[(index2 + 1) % 2]))
+                wait_log_commit(log_root_tree, log_root_tree->log_transid - 1);
+
+        wait_for_writer(log_root_tree);
+
+        ret = btrfs_write_and_wait_marked_extents(log_root_tree,
+                                &log_root_tree->dirty_log_pages);
         BUG_ON(ret);
 
         btrfs_set_super_log_root(&root->fs_info->super_for_commit,
-                                 log->fs_info->log_root_tree->node->start);
+                                log_root_tree->node->start);
         btrfs_set_super_log_root_level(&root->fs_info->super_for_commit,
-                       btrfs_header_level(log->fs_info->log_root_tree->node));
+                                btrfs_header_level(log_root_tree->node));
+
+        log_root_tree->log_batch = 0;
+        log_root_tree->log_transid++;
+        smp_mb();
+
+        mutex_unlock(&log_root_tree->log_mutex);
+
+        /*
+         * nobody else is going to jump in and write the the ctree
+         * super here because the log_commit atomic below is protecting
+         * us.  We must be called with a transaction handle pinning
+         * the running transaction open, so a full commit can't hop
+         * in and cause problems either.
+         */
+        write_ctree_super(trans, root->fs_info->tree_root, 2);
 
-        write_ctree_super(trans, log->fs_info->tree_root, 2);
-        log->fs_info->tree_log_transid++;
-        log->fs_info->tree_log_batch = 0;
-        atomic_set(&log->fs_info->tree_log_commit, 0);
+        atomic_set(&log_root_tree->log_commit[index2], 0);
         smp_mb();
-        if (waitqueue_active(&log->fs_info->tree_log_wait))
-                wake_up(&log->fs_info->tree_log_wait);
+        if (waitqueue_active(&log_root_tree->log_commit_wait[index2]))
+                wake_up(&log_root_tree->log_commit_wait[index2]);
 out:
-        mutex_unlock(&log->fs_info->tree_log_mutex);
+        atomic_set(&root->log_commit[index1], 0);
+        smp_mb();
+        if (waitqueue_active(&root->log_commit_wait[index1]))
+                wake_up(&root->log_commit_wait[index1]);
         return 0;
 }
 
@@ -2019,38 +2030,18 @@ int btrfs_free_log(struct btrfs_trans_handle *trans, struct btrfs_root *root)
                                    start, end, GFP_NOFS);
         }
 
-        log = root->log_root;
-        ret = btrfs_del_root(trans, root->fs_info->log_root_tree,
-                             &log->root_key);
-        BUG_ON(ret);
+        if (log->log_transid > 0) {
+                ret = btrfs_del_root(trans, root->fs_info->log_root_tree,
+                                     &log->root_key);
+                BUG_ON(ret);
+        }
         root->log_root = NULL;
-        kfree(root->log_root);
+        free_extent_buffer(log->node);
+        kfree(log);
         return 0;
 }
 
 /*
- * helper function to update the item for a given subvolumes log root
- * in the tree of log roots
- */
-static int update_log_root(struct btrfs_trans_handle *trans,
-                           struct btrfs_root *log)
-{
-        u64 bytenr = btrfs_root_bytenr(&log->root_item);
-        int ret;
-
-        if (log->node->start == bytenr)
-                return 0;
-
-        btrfs_set_root_bytenr(&log->root_item, log->node->start);
-        btrfs_set_root_generation(&log->root_item, trans->transid);
-        btrfs_set_root_level(&log->root_item, btrfs_header_level(log->node));
-        ret = btrfs_update_root(trans, log->fs_info->log_root_tree,
-                                &log->root_key, &log->root_item);
-        BUG_ON(ret);
-        return ret;
-}
-
-/*
  * If both a file and directory are logged, and unlinks or renames are
  * mixed in, we have a few interesting corners:
  *
@@ -2711,11 +2702,6 @@ next_slot:
 
         btrfs_free_path(path);
         btrfs_free_path(dst_path);
-
-        mutex_lock(&root->fs_info->tree_log_mutex);
-        ret = update_log_root(trans, log);
-        BUG_ON(ret);
-        mutex_unlock(&root->fs_info->tree_log_mutex);
 out:
         return 0;
 }
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 3451e1cca2b5..bcd14ebccae1 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -20,7 +20,6 @@
 #include <linux/buffer_head.h>
 #include <linux/blkdev.h>
 #include <linux/random.h>
-#include <linux/version.h>
 #include <asm/div64.h>
 #include "compat.h"
 #include "ctree.h"
@@ -104,10 +103,8 @@ static noinline struct btrfs_device *__find_device(struct list_head *head,
                                                    u64 devid, u8 *uuid)
 {
         struct btrfs_device *dev;
-        struct list_head *cur;
 
-        list_for_each(cur, head) {
-                dev = list_entry(cur, struct btrfs_device, dev_list);
+        list_for_each_entry(dev, head, dev_list) {
                 if (dev->devid == devid &&
                     (!uuid || !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE))) {
                         return dev;
@@ -118,11 +115,9 @@ static noinline struct btrfs_device *__find_device(struct list_head *head,
 
 static noinline struct btrfs_fs_devices *find_fsid(u8 *fsid)
 {
-        struct list_head *cur;
         struct btrfs_fs_devices *fs_devices;
 
-        list_for_each(cur, &fs_uuids) {
-                fs_devices = list_entry(cur, struct btrfs_fs_devices, list);
+        list_for_each_entry(fs_devices, &fs_uuids, list) {
                 if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
                         return fs_devices;
         }
@@ -159,6 +154,7 @@ static noinline int run_scheduled_bios(struct btrfs_device *device)
 loop:
         spin_lock(&device->io_lock);
 
+loop_lock:
         /* take all the bios off the list at once and process them
          * later on (without the lock held).  But, remember the
          * tail and other pointers so the bios can be properly reinserted
@@ -208,7 +204,7 @@ loop:
                  * is now congested.  Back off and let other work structs
                  * run instead
                  */
-                if (pending && bdi_write_congested(bdi) &&
+                if (pending && bdi_write_congested(bdi) && num_run > 16 &&
                     fs_info->fs_devices->open_devices > 1) {
                         struct bio *old_head;
 
@@ -220,7 +216,8 @@ loop:
                                 tail->bi_next = old_head;
                         else
                                 device->pending_bio_tail = tail;
-                        device->running_pending = 0;
+
+                        device->running_pending = 1;
 
                         spin_unlock(&device->io_lock);
                         btrfs_requeue_work(&device->work);
@@ -229,6 +226,11 @@ loop:
         }
         if (again)
                 goto loop;
+
+        spin_lock(&device->io_lock);
+        if (device->pending_bios)
+                goto loop_lock;
+        spin_unlock(&device->io_lock);
 done:
         return 0;
 }
@@ -345,14 +347,11 @@ error:
 
 int btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices)
 {
-        struct list_head *tmp;
-        struct list_head *cur;
-        struct btrfs_device *device;
+        struct btrfs_device *device, *next;
 
         mutex_lock(&uuid_mutex);
 again:
-        list_for_each_safe(cur, tmp, &fs_devices->devices) {
-                device = list_entry(cur, struct btrfs_device, dev_list);
+        list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
                 if (device->in_fs_metadata)
                         continue;
 
@@ -383,14 +382,12 @@ again:
 
 static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
 {
-        struct list_head *cur;
         struct btrfs_device *device;
 
         if (--fs_devices->opened > 0)
                 return 0;
 
-        list_for_each(cur, &fs_devices->devices) {
-                device = list_entry(cur, struct btrfs_device, dev_list);
+        list_for_each_entry(device, &fs_devices->devices, dev_list) {
                 if (device->bdev) {
                         close_bdev_exclusive(device->bdev, device->mode);
                         fs_devices->open_devices--;
@@ -439,7 +436,6 @@ static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
 {
         struct block_device *bdev;
         struct list_head *head = &fs_devices->devices;
-        struct list_head *cur;
         struct btrfs_device *device;
         struct block_device *latest_bdev = NULL;
         struct buffer_head *bh;
@@ -450,8 +446,7 @@ static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
         int seeding = 1;
         int ret = 0;
 
-        list_for_each(cur, head) {
-                device = list_entry(cur, struct btrfs_device, dev_list);
+        list_for_each_entry(device, head, dev_list) {
                 if (device->bdev)
                         continue;
                 if (!device->name)
@@ -578,7 +573,7 @@ int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
                        *(unsigned long long *)disk_super->fsid,
                        *(unsigned long long *)(disk_super->fsid + 8));
         }
-        printk(KERN_INFO "devid %llu transid %llu %s\n",
+        printk(KERN_CONT "devid %llu transid %llu %s\n",
                (unsigned long long)devid, (unsigned long long)transid, path);
         ret = device_list_add(path, disk_super, devid, fs_devices_ret);
 
@@ -1017,14 +1012,12 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
         }
 
         if (strcmp(device_path, "missing") == 0) {
-                struct list_head *cur;
                 struct list_head *devices;
                 struct btrfs_device *tmp;
 
                 device = NULL;
                 devices = &root->fs_info->fs_devices->devices;
-                list_for_each(cur, devices) {
-                        tmp = list_entry(cur, struct btrfs_device, dev_list);
+                list_for_each_entry(tmp, devices, dev_list) {
                         if (tmp->in_fs_metadata && !tmp->bdev) {
                                 device = tmp;
                                 break;
@@ -1280,7 +1273,6 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
         struct btrfs_trans_handle *trans;
         struct btrfs_device *device;
         struct block_device *bdev;
-        struct list_head *cur;
         struct list_head *devices;
         struct super_block *sb = root->fs_info->sb;
         u64 total_bytes;
@@ -1304,8 +1296,7 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
         mutex_lock(&root->fs_info->volume_mutex);
 
         devices = &root->fs_info->fs_devices->devices;
-        list_for_each(cur, devices) {
-                device = list_entry(cur, struct btrfs_device, dev_list);
+        list_for_each_entry(device, devices, dev_list) {
                 if (device->bdev == bdev) {
                         ret = -EEXIST;
                         goto error;
@@ -1704,7 +1695,6 @@ static u64 div_factor(u64 num, int factor)
 int btrfs_balance(struct btrfs_root *dev_root)
 {
         int ret;
-        struct list_head *cur;
         struct list_head *devices = &dev_root->fs_info->fs_devices->devices;
         struct btrfs_device *device;
         u64 old_size;
@@ -1723,8 +1713,7 @@ int btrfs_balance(struct btrfs_root *dev_root)
         dev_root = dev_root->fs_info->dev_root;
 
         /* step one make some room on all the devices */
-        list_for_each(cur, devices) {
-                device = list_entry(cur, struct btrfs_device, dev_list);
+        list_for_each_entry(device, devices, dev_list) {
                 old_size = device->total_bytes;
                 size_to_free = div_factor(old_size, 1);
                 size_to_free = min(size_to_free, (u64)1 * 1024 * 1024);
diff --git a/fs/btrfs/xattr.c b/fs/btrfs/xattr.c
index 7f332e270894..a9d3bf4d2689 100644
--- a/fs/btrfs/xattr.c
+++ b/fs/btrfs/xattr.c
@@ -21,6 +21,7 @@
 #include <linux/slab.h>
 #include <linux/rwsem.h>
 #include <linux/xattr.h>
+#include <linux/security.h>
 #include "ctree.h"
 #include "btrfs_inode.h"
 #include "transaction.h"
@@ -45,9 +46,12 @@ ssize_t __btrfs_getxattr(struct inode *inode, const char *name,
         /* lookup the xattr by name */
         di = btrfs_lookup_xattr(NULL, root, path, inode->i_ino, name,
                                 strlen(name), 0);
-        if (!di || IS_ERR(di)) {
+        if (!di) {
                 ret = -ENODATA;
                 goto out;
+        } else if (IS_ERR(di)) {
+                ret = PTR_ERR(di);
+                goto out;
         }
 
         leaf = path->nodes[0];
@@ -62,6 +66,14 @@ ssize_t __btrfs_getxattr(struct inode *inode, const char *name,
                 ret = -ERANGE;
                 goto out;
         }
+
+        /*
+         * The way things are packed into the leaf is like this
+         * |struct btrfs_dir_item|name|data|
+         * where name is the xattr name, so security.foo, and data is the
+         * content of the xattr.  data_ptr points to the location in memory
+         * where the data starts in the in memory leaf
+         */
         data_ptr = (unsigned long)((char *)(di + 1) +
                                    btrfs_dir_name_len(leaf, di));
         read_extent_buffer(leaf, buffer, data_ptr,
@@ -86,7 +98,7 @@ int __btrfs_setxattr(struct inode *inode, const char *name,
         if (!path)
                 return -ENOMEM;
 
-        trans = btrfs_start_transaction(root, 1);
+        trans = btrfs_join_transaction(root, 1);
         btrfs_set_trans_block_group(trans, inode);
 
         /* first lets see if we already have this xattr */
@@ -176,7 +188,6 @@ ssize_t btrfs_listxattr(struct dentry *dentry, char *buffer, size_t size)
         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
         if (ret < 0)
                 goto err;
-        ret = 0;
         advance = 0;
         while (1) {
                 leaf = path->nodes[0];
@@ -320,3 +331,34 @@ int btrfs_removexattr(struct dentry *dentry, const char *name)
                 return -EOPNOTSUPP;
         return __btrfs_setxattr(dentry->d_inode, name, NULL, 0, XATTR_REPLACE);
 }
+
+int btrfs_xattr_security_init(struct inode *inode, struct inode *dir)
+{
+        int err;
+        size_t len;
+        void *value;
+        char *suffix;
+        char *name;
+
+        err = security_inode_init_security(inode, dir, &suffix, &value, &len);
+        if (err) {
+                if (err == -EOPNOTSUPP)
+                        return 0;
+                return err;
+        }
+
+        name = kmalloc(XATTR_SECURITY_PREFIX_LEN + strlen(suffix) + 1,
+                       GFP_NOFS);
+        if (!name) {
+                err = -ENOMEM;
+        } else {
+                strcpy(name, XATTR_SECURITY_PREFIX);
+                strcpy(name + XATTR_SECURITY_PREFIX_LEN, suffix);
+                err = __btrfs_setxattr(inode, name, value, len, 0);
+                kfree(name);
+        }
+
+        kfree(suffix);
+        kfree(value);
+        return err;
+}
diff --git a/fs/btrfs/xattr.h b/fs/btrfs/xattr.h
index 5b1d08f8e68d..c71e9c3cf3f7 100644
--- a/fs/btrfs/xattr.h
+++ b/fs/btrfs/xattr.h
@@ -36,4 +36,6 @@ extern int btrfs_setxattr(struct dentry *dentry, const char *name,
                 const void *value, size_t size, int flags);
 extern int btrfs_removexattr(struct dentry *dentry, const char *name);
 
+extern int btrfs_xattr_security_init(struct inode *inode, struct inode *dir);
+
 #endif /* __XATTR__ */