Merge branch 'for-chris' of git://repo.or.cz/linux-btrfs-devel into integration

Conflicts:
	fs/btrfs/volumes.c

Signed-off-by: Chris Mason <chris.mason@oracle.com>

6 files changed, 280 insertions, 226 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 9c1a744e595b..e5167219c266 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2278,9 +2278,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
            (unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node),
            BTRFS_UUID_SIZE);
 
-        mutex_lock(&fs_info->chunk_mutex);
         ret = btrfs_read_chunk_tree(chunk_root);
-        mutex_unlock(&fs_info->chunk_mutex);
         if (ret) {
                 printk(KERN_WARNING "btrfs: failed to read chunk tree on %s\n",
                        sb->s_id);
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 352083ad233c..1c1cf216be80 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -7143,7 +7143,7 @@ int btrfs_can_relocate(struct btrfs_root *root, u64 bytenr)
                  * space to fit our block group in.
                  */
                 if (device->total_bytes > device->bytes_used + min_free) {
-                        ret = find_free_dev_extent(NULL, device, min_free,
+                        ret = find_free_dev_extent(device, min_free,
                                                    &dev_offset, NULL);
                         if (!ret)
                                 dev_nr++;
@@ -7505,6 +7505,7 @@ int btrfs_make_block_group(struct btrfs_trans_handle *trans,
         ret = update_space_info(root->fs_info, cache->flags, size, bytes_used,
                                 &cache->space_info);
         BUG_ON(ret);
+        update_global_block_rsv(root->fs_info);
 
         spin_lock(&cache->space_info->lock);
         cache->space_info->bytes_readonly += cache->bytes_super;
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index ce40db59c706..6c7887a7770c 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -319,9 +319,11 @@ static void io_ctl_drop_pages(struct io_ctl *io_ctl)
         io_ctl_unmap_page(io_ctl);
 
         for (i = 0; i < io_ctl->num_pages; i++) {
-                ClearPageChecked(io_ctl->pages[i]);
-                unlock_page(io_ctl->pages[i]);
-                page_cache_release(io_ctl->pages[i]);
+                if (io_ctl->pages[i]) {
+                        ClearPageChecked(io_ctl->pages[i]);
+                        unlock_page(io_ctl->pages[i]);
+                        page_cache_release(io_ctl->pages[i]);
+                }
         }
 }
 
@@ -635,7 +637,10 @@ int __load_free_space_cache(struct btrfs_root *root, struct inode *inode,
         if (!num_entries)
                 return 0;
 
-        io_ctl_init(&io_ctl, inode, root);
+        ret = io_ctl_init(&io_ctl, inode, root);
+        if (ret)
+                return ret;
+
         ret = readahead_cache(inode);
         if (ret)
                 goto out;
@@ -838,7 +843,7 @@ int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
         struct io_ctl io_ctl;
         struct list_head bitmap_list;
         struct btrfs_key key;
-        u64 start, end, len;
+        u64 start, extent_start, extent_end, len;
         int entries = 0;
         int bitmaps = 0;
         int ret;
@@ -849,7 +854,9 @@ int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
         if (!i_size_read(inode))
                 return -1;
 
-        io_ctl_init(&io_ctl, inode, root);
+        ret = io_ctl_init(&io_ctl, inode, root);
+        if (ret)
+                return -1;
 
         /* Get the cluster for this block_group if it exists */
         if (block_group && !list_empty(&block_group->cluster_list))
@@ -857,25 +864,12 @@ int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
                                      struct btrfs_free_cluster,
                                      block_group_list);
 
-        /*
-         * We shouldn't have switched the pinned extents yet so this is the
-         * right one
-         */
-        unpin = root->fs_info->pinned_extents;
-
         /* Lock all pages first so we can lock the extent safely. */
         io_ctl_prepare_pages(&io_ctl, inode, 0);
 
         lock_extent_bits(&BTRFS_I(inode)->io_tree, 0, i_size_read(inode) - 1,
                          0, &cached_state, GFP_NOFS);
 
-        /*
-         * When searching for pinned extents, we need to start at our start
-         * offset.
-         */
-        if (block_group)
-                start = block_group->key.objectid;
-
         node = rb_first(&ctl->free_space_offset);
         if (!node && cluster) {
                 node = rb_first(&cluster->root);
@@ -918,9 +912,20 @@ int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
          * We want to add any pinned extents to our free space cache
          * so we don't leak the space
          */
+
+        /*
+         * We shouldn't have switched the pinned extents yet so this is the
+         * right one
+         */
+        unpin = root->fs_info->pinned_extents;
+
+        if (block_group)
+                start = block_group->key.objectid;
+
         while (block_group && (start < block_group->key.objectid +
                                block_group->key.offset)) {
-                ret = find_first_extent_bit(unpin, start, &start, &end,
+                ret = find_first_extent_bit(unpin, start,
+                                            &extent_start, &extent_end,
                                             EXTENT_DIRTY);
                 if (ret) {
                         ret = 0;
@@ -928,20 +933,21 @@ int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
                 }
 
                 /* This pinned extent is out of our range */
-                if (start >= block_group->key.objectid +
+                if (extent_start >= block_group->key.objectid +
                     block_group->key.offset)
                         break;
 
-                len = block_group->key.objectid +
-                        block_group->key.offset - start;
-                len = min(len, end + 1 - start);
+                extent_start = max(extent_start, start);
+                extent_end = min(block_group->key.objectid +
+                                 block_group->key.offset, extent_end + 1);
+                len = extent_end - extent_start;
 
                 entries++;
-                ret = io_ctl_add_entry(&io_ctl, start, len, NULL);
+                ret = io_ctl_add_entry(&io_ctl, extent_start, len, NULL);
                 if (ret)
                         goto out_nospc;
 
-                start = end + 1;
+                start = extent_end;
         }
 
         /* Write out the bitmaps */
@@ -2574,17 +2580,57 @@ void btrfs_init_free_cluster(struct btrfs_free_cluster *cluster)
         cluster->block_group = NULL;
 }
 
-int btrfs_trim_block_group(struct btrfs_block_group_cache *block_group,
-                           u64 *trimmed, u64 start, u64 end, u64 minlen)
+static int do_trimming(struct btrfs_block_group_cache *block_group,
+                       u64 *total_trimmed, u64 start, u64 bytes,
+                       u64 reserved_start, u64 reserved_bytes)
 {
-        struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
-        struct btrfs_free_space *entry = NULL;
+        struct btrfs_space_info *space_info = block_group->space_info;
         struct btrfs_fs_info *fs_info = block_group->fs_info;
-        u64 bytes = 0;
-        u64 actually_trimmed;
-        int ret = 0;
+        int ret;
+        int update = 0;
+        u64 trimmed = 0;
 
-        *trimmed = 0;
+        spin_lock(&space_info->lock);
+        spin_lock(&block_group->lock);
+        if (!block_group->ro) {
+                block_group->reserved += reserved_bytes;
+                space_info->bytes_reserved += reserved_bytes;
+                update = 1;
+        }
+        spin_unlock(&block_group->lock);
+        spin_unlock(&space_info->lock);
+
+        ret = btrfs_error_discard_extent(fs_info->extent_root,
+                                         start, bytes, &trimmed);
+        if (!ret)
+                *total_trimmed += trimmed;
+
+        btrfs_add_free_space(block_group, reserved_start, reserved_bytes);
+
+        if (update) {
+                spin_lock(&space_info->lock);
+                spin_lock(&block_group->lock);
+                if (block_group->ro)
+                        space_info->bytes_readonly += reserved_bytes;
+                block_group->reserved -= reserved_bytes;
+                space_info->bytes_reserved -= reserved_bytes;
+                spin_unlock(&space_info->lock);
+                spin_unlock(&block_group->lock);
+        }
+
+        return ret;
+}
+
+static int trim_no_bitmap(struct btrfs_block_group_cache *block_group,
+                          u64 *total_trimmed, u64 start, u64 end, u64 minlen)
+{
+        struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
+        struct btrfs_free_space *entry;
+        struct rb_node *node;
+        int ret = 0;
+        u64 extent_start;
+        u64 extent_bytes;
+        u64 bytes;
 
         while (start < end) {
                 spin_lock(&ctl->tree_lock);
@@ -2595,81 +2641,118 @@ int btrfs_trim_block_group(struct btrfs_block_group_cache *block_group,
                 }
 
                 entry = tree_search_offset(ctl, start, 0, 1);
-                if (!entry)
-                        entry = tree_search_offset(ctl,
-                                                   offset_to_bitmap(ctl, start),
-                                                   1, 1);
-
-                if (!entry || entry->offset >= end) {
+                if (!entry) {
                         spin_unlock(&ctl->tree_lock);
                         break;
                 }
 
-                if (entry->bitmap) {
-                        ret = search_bitmap(ctl, entry, &start, &bytes);
-                        if (!ret) {
-                                if (start >= end) {
-                                        spin_unlock(&ctl->tree_lock);
-                                        break;
-                                }
-                                bytes = min(bytes, end - start);
-                                bitmap_clear_bits(ctl, entry, start, bytes);
-                                if (entry->bytes == 0)
-                                        free_bitmap(ctl, entry);
-                        } else {
-                                start = entry->offset + BITS_PER_BITMAP *
-                                        block_group->sectorsize;
+                /* skip bitmaps */
+                while (entry->bitmap) {
+                        node = rb_next(&entry->offset_index);
+                        if (!node) {
                                 spin_unlock(&ctl->tree_lock);
-                                ret = 0;
-                                continue;
+                                goto out;
                         }
-                } else {
-                        start = entry->offset;
-                        bytes = min(entry->bytes, end - start);
-                        unlink_free_space(ctl, entry);
-                        kmem_cache_free(btrfs_free_space_cachep, entry);
+                        entry = rb_entry(node, struct btrfs_free_space,
+                                         offset_index);
+                }
+
+                if (entry->offset >= end) {
+                        spin_unlock(&ctl->tree_lock);
+                        break;
                 }
 
+                extent_start = entry->offset;
+                extent_bytes = entry->bytes;
+                start = max(start, extent_start);
+                bytes = min(extent_start + extent_bytes, end) - start;
+                if (bytes < minlen) {
+                        spin_unlock(&ctl->tree_lock);
+                        goto next;
+                }
+
+                unlink_free_space(ctl, entry);
+                kmem_cache_free(btrfs_free_space_cachep, entry);
+
                 spin_unlock(&ctl->tree_lock);
 
-                if (bytes >= minlen) {
-                        struct btrfs_space_info *space_info;
-                        int update = 0;
-
-                        space_info = block_group->space_info;
-                        spin_lock(&space_info->lock);
-                        spin_lock(&block_group->lock);
-                        if (!block_group->ro) {
-                                block_group->reserved += bytes;
-                                space_info->bytes_reserved += bytes;
-                                update = 1;
-                        }
-                        spin_unlock(&block_group->lock);
-                        spin_unlock(&space_info->lock);
-
-                        ret = btrfs_error_discard_extent(fs_info->extent_root,
-                                                         start,
-                                                         bytes,
-                                                         &actually_trimmed);
-
-                        btrfs_add_free_space(block_group, start, bytes);
-                        if (update) {
-                                spin_lock(&space_info->lock);
-                                spin_lock(&block_group->lock);
-                                if (block_group->ro)
-                                        space_info->bytes_readonly += bytes;
-                                block_group->reserved -= bytes;
-                                space_info->bytes_reserved -= bytes;
-                                spin_unlock(&space_info->lock);
-                                spin_unlock(&block_group->lock);
-                        }
+                ret = do_trimming(block_group, total_trimmed, start, bytes,
+                                  extent_start, extent_bytes);
+                if (ret)
+                        break;
+next:
+                start += bytes;
 
-                        if (ret)
-                                break;
-                        *trimmed += actually_trimmed;
+                if (fatal_signal_pending(current)) {
+                        ret = -ERESTARTSYS;
+                        break;
+                }
+
+                cond_resched();
+        }
+out:
+        return ret;
+}
+
+static int trim_bitmaps(struct btrfs_block_group_cache *block_group,
+                        u64 *total_trimmed, u64 start, u64 end, u64 minlen)
+{
+        struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
+        struct btrfs_free_space *entry;
+        int ret = 0;
+        int ret2;
+        u64 bytes;
+        u64 offset = offset_to_bitmap(ctl, start);
+
+        while (offset < end) {
+                bool next_bitmap = false;
+
+                spin_lock(&ctl->tree_lock);
+
+                if (ctl->free_space < minlen) {
+                        spin_unlock(&ctl->tree_lock);
+                        break;
+                }
+
+                entry = tree_search_offset(ctl, offset, 1, 0);
+                if (!entry) {
+                        spin_unlock(&ctl->tree_lock);
+                        next_bitmap = true;
+                        goto next;
+                }
+
+                bytes = minlen;
+                ret2 = search_bitmap(ctl, entry, &start, &bytes);
+                if (ret2 || start >= end) {
+                        spin_unlock(&ctl->tree_lock);
+                        next_bitmap = true;
+                        goto next;
+                }
+
+                bytes = min(bytes, end - start);
+                if (bytes < minlen) {
+                        spin_unlock(&ctl->tree_lock);
+                        goto next;
+                }
+
+                bitmap_clear_bits(ctl, entry, start, bytes);
+                if (entry->bytes == 0)
+                        free_bitmap(ctl, entry);
+
+                spin_unlock(&ctl->tree_lock);
+
+                ret = do_trimming(block_group, total_trimmed, start, bytes,
+                                  start, bytes);
+                if (ret)
+                        break;
+next:
+                if (next_bitmap) {
+                        offset += BITS_PER_BITMAP * ctl->unit;
+                } else {
+                        start += bytes;
+                        if (start >= offset + BITS_PER_BITMAP * ctl->unit)
+                                offset += BITS_PER_BITMAP * ctl->unit;
                 }
-                start += bytes;
-                bytes = 0;
 
                 if (fatal_signal_pending(current)) {
                         ret = -ERESTARTSYS;
@@ -2682,6 +2765,22 @@ int btrfs_trim_block_group(struct btrfs_block_group_cache *block_group,
         return ret;
 }
 
+int btrfs_trim_block_group(struct btrfs_block_group_cache *block_group,
+                           u64 *trimmed, u64 start, u64 end, u64 minlen)
+{
+        int ret;
+
+        *trimmed = 0;
+
+        ret = trim_no_bitmap(block_group, trimmed, start, end, minlen);
+        if (ret)
+                return ret;
+
+        ret = trim_bitmaps(block_group, trimmed, start, end, minlen);
+
+        return ret;
+}
+
 /*
  * Find the left-most item in the cache tree, and then return the
  * smallest inode number in the item.
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 1e7a9bac31ab..ef909b5d3d2e 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -176,6 +176,8 @@ static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
         struct btrfs_trans_handle *trans;
         unsigned int flags, oldflags;
         int ret;
+        u64 ip_oldflags;
+        unsigned int i_oldflags;
 
         if (btrfs_root_readonly(root))
                 return -EROFS;
@@ -192,6 +194,9 @@ static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
 
         mutex_lock(&inode->i_mutex);
 
+        ip_oldflags = ip->flags;
+        i_oldflags = inode->i_flags;
+
         flags = btrfs_mask_flags(inode->i_mode, flags);
         oldflags = btrfs_flags_to_ioctl(ip->flags);
         if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
@@ -249,19 +254,24 @@ static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
                 ip->flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS);
         }
 
-        trans = btrfs_join_transaction(root);
-        BUG_ON(IS_ERR(trans));
+        trans = btrfs_start_transaction(root, 1);
+        if (IS_ERR(trans)) {
+                ret = PTR_ERR(trans);
+                goto out_drop;
+        }
 
         btrfs_update_iflags(inode);
         inode->i_ctime = CURRENT_TIME;
         ret = btrfs_update_inode(trans, root, inode);
-        BUG_ON(ret);
 
         btrfs_end_transaction(trans, root);
+ out_drop:
+        if (ret) {
+                ip->flags = ip_oldflags;
+                inode->i_flags = i_oldflags;
+        }
 
         mnt_drop_write(file->f_path.mnt);
-
-        ret = 0;
  out_unlock:
         mutex_unlock(&inode->i_mutex);
         return ret;
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 9489a2aca47b..e0b7bb92a170 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -830,7 +830,6 @@ out:
 
 /*
  * find_free_dev_extent - find free space in the specified device
- * @trans:      transaction handler
  * @device:     the device which we search the free space in
  * @num_bytes:  the size of the free space that we need
  * @start:      store the start of the free space.
@@ -849,8 +848,7 @@ out:
  * But if we don't find suitable free space, it is used to store the size of
  * the max free space.
  */
-int find_free_dev_extent(struct btrfs_trans_handle *trans,
-                         struct btrfs_device *device, u64 num_bytes,
+int find_free_dev_extent(struct btrfs_device *device, u64 num_bytes,
                          u64 *start, u64 *len)
 {
         struct btrfs_key key;
@@ -894,7 +892,7 @@ int find_free_dev_extent(struct btrfs_trans_handle *trans,
         key.offset = search_start;
         key.type = BTRFS_DEV_EXTENT_KEY;
 
-        ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
+        ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
         if (ret < 0)
                 goto out;
         if (ret > 0) {
@@ -1468,8 +1466,7 @@ error_undo:
 /*
  * does all the dirty work required for changing file system's UUID.
  */
-static int btrfs_prepare_sprout(struct btrfs_trans_handle *trans,
-                                struct btrfs_root *root)
+static int btrfs_prepare_sprout(struct btrfs_root *root)
 {
         struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
         struct btrfs_fs_devices *old_devices;
@@ -1693,7 +1690,7 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
 
         if (seeding_dev) {
                 sb->s_flags &= ~MS_RDONLY;
-                ret = btrfs_prepare_sprout(trans, root);
+                ret = btrfs_prepare_sprout(root);
                 BUG_ON(ret);
         }
 
@@ -3044,8 +3041,7 @@ done:
         return ret;
 }
 
-static int btrfs_add_system_chunk(struct btrfs_trans_handle *trans,
-                           struct btrfs_root *root,
+static int btrfs_add_system_chunk(struct btrfs_root *root,
                            struct btrfs_key *key,
                            struct btrfs_chunk *chunk, int item_size)
 {
@@ -3221,7 +3217,7 @@ static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
                 if (total_avail == 0)
                         continue;
 
-                ret = find_free_dev_extent(trans, device,
+                ret = find_free_dev_extent(device,
                                            max_stripe_size * dev_stripes,
                                            &dev_offset, &max_avail);
                 if (ret && ret != -ENOSPC)
@@ -3412,7 +3408,7 @@ static int __finish_chunk_alloc(struct btrfs_trans_handle *trans,
         BUG_ON(ret);
 
         if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
-                ret = btrfs_add_system_chunk(trans, chunk_root, &key, chunk,
+                ret = btrfs_add_system_chunk(chunk_root, &key, chunk,
                                              item_size);
                 BUG_ON(ret);
         }
@@ -3624,26 +3620,13 @@ static int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
         u64 stripe_nr;
         u64 stripe_nr_orig;
         u64 stripe_nr_end;
-        int stripes_allocated = 8;
-        int stripes_required = 1;
         int stripe_index;
         int i;
+        int ret = 0;
         int num_stripes;
         int max_errors = 0;
         struct btrfs_bio *bbio = NULL;
 
-        if (bbio_ret && !(rw & (REQ_WRITE | REQ_DISCARD)))
-                stripes_allocated = 1;
-again:
-        if (bbio_ret) {
-                bbio = kzalloc(btrfs_bio_size(stripes_allocated),
-                                GFP_NOFS);
-                if (!bbio)
-                        return -ENOMEM;
-
-                atomic_set(&bbio->error, 0);
-        }
-
         read_lock(&em_tree->lock);
         em = lookup_extent_mapping(em_tree, logical, *length);
         read_unlock(&em_tree->lock);
@@ -3662,28 +3645,6 @@ again:
         if (mirror_num > map->num_stripes)
                 mirror_num = 0;
 
-        /* if our btrfs_bio struct is too small, back off and try again */
-        if (rw & REQ_WRITE) {
-                if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
-                                 BTRFS_BLOCK_GROUP_DUP)) {
-                        stripes_required = map->num_stripes;
-                        max_errors = 1;
-                } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
-                        stripes_required = map->sub_stripes;
-                        max_errors = 1;
-                }
-        }
-        if (rw & REQ_DISCARD) {
-                if (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK)
-                        stripes_required = map->num_stripes;
-        }
-        if (bbio_ret && (rw & (REQ_WRITE | REQ_DISCARD)) &&
-            stripes_allocated < stripes_required) {
-                stripes_allocated = map->num_stripes;
-                free_extent_map(em);
-                kfree(bbio);
-                goto again;
-        }
         stripe_nr = offset;
         /*
          * stripe_nr counts the total number of stripes we have to stride
@@ -3775,81 +3736,55 @@ again:
         }
         BUG_ON(stripe_index >= map->num_stripes);
 
+        bbio = kzalloc(btrfs_bio_size(num_stripes), GFP_NOFS);
+        if (!bbio) {
+                ret = -ENOMEM;
+                goto out;
+        }
+        atomic_set(&bbio->error, 0);
+
         if (rw & REQ_DISCARD) {
+                int factor = 0;
+                int sub_stripes = 0;
+                u64 stripes_per_dev = 0;
+                u32 remaining_stripes = 0;
+
+                if (map->type &
+                    (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10)) {
+                        if (map->type & BTRFS_BLOCK_GROUP_RAID0)
+                                sub_stripes = 1;
+                        else
+                                sub_stripes = map->sub_stripes;
+
+                        factor = map->num_stripes / sub_stripes;
+                        stripes_per_dev = div_u64_rem(stripe_nr_end -
+                                                      stripe_nr_orig,
+                                                      factor,
+                                                      &remaining_stripes);
+                }
+
                 for (i = 0; i < num_stripes; i++) {
                         bbio->stripes[i].physical =
                                 map->stripes[stripe_index].physical +
                                 stripe_offset + stripe_nr * map->stripe_len;
                         bbio->stripes[i].dev = map->stripes[stripe_index].dev;
 
-                        if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
-                                u64 stripes;
-                                u32 last_stripe = 0;
-                                int j;
-
-                                div_u64_rem(stripe_nr_end - 1,
-                                            map->num_stripes,
-                                            &last_stripe);
-
-                                for (j = 0; j < map->num_stripes; j++) {
-                                        u32 test;
-
-                                        div_u64_rem(stripe_nr_end - 1 - j,
-                                                    map->num_stripes, &test);
-                                        if (test == stripe_index)
-                                                break;
-                                }
-                                stripes = stripe_nr_end - 1 - j;
-                                do_div(stripes, map->num_stripes);
-                                bbio->stripes[i].length = map->stripe_len *
-                                        (stripes - stripe_nr + 1);
-
-                                if (i == 0) {
-                                        bbio->stripes[i].length -=
-                                                stripe_offset;
-                                        stripe_offset = 0;
-                                }
-                                if (stripe_index == last_stripe)
-                                        bbio->stripes[i].length -=
-                                                stripe_end_offset;
-                        } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
-                                u64 stripes;
-                                int j;
-                                int factor = map->num_stripes /
-                                             map->sub_stripes;
-                                u32 last_stripe = 0;
-
-                                div_u64_rem(stripe_nr_end - 1,
-                                            factor, &last_stripe);
-                                last_stripe *= map->sub_stripes;
-
-                                for (j = 0; j < factor; j++) {
-                                        u32 test;
-
-                                        div_u64_rem(stripe_nr_end - 1 - j,
-                                                    factor, &test);
-
-                                        if (test ==
-                                            stripe_index / map->sub_stripes)
-                                                break;
-                                }
-                                stripes = stripe_nr_end - 1 - j;
-                                do_div(stripes, factor);
-                                bbio->stripes[i].length = map->stripe_len *
-                                        (stripes - stripe_nr + 1);
-
-                                if (i < map->sub_stripes) {
+                        if (map->type & (BTRFS_BLOCK_GROUP_RAID0 |
+                                         BTRFS_BLOCK_GROUP_RAID10)) {
+                                bbio->stripes[i].length = stripes_per_dev *
+                                                          map->stripe_len;
+                                if (i / sub_stripes < remaining_stripes)
+                                        bbio->stripes[i].length +=
+                                                map->stripe_len;
+                                if (i < sub_stripes)
                                         bbio->stripes[i].length -=
                                                 stripe_offset;
-                                        if (i == map->sub_stripes - 1)
-                                                stripe_offset = 0;
-                                }
-                                if (stripe_index >= last_stripe &&
-                                    stripe_index <= (last_stripe +
-                                                     map->sub_stripes - 1)) {
+                                if ((i / sub_stripes + 1) %
+                                    sub_stripes == remaining_stripes)
                                         bbio->stripes[i].length -=
                                                 stripe_end_offset;
-                                }
+                                if (i == sub_stripes - 1)
+                                        stripe_offset = 0;
                         } else
                                 bbio->stripes[i].length = *length;
 
@@ -3871,15 +3806,22 @@ again:
                         stripe_index++;
                 }
         }
-        if (bbio_ret) {
-                *bbio_ret = bbio;
-                bbio->num_stripes = num_stripes;
-                bbio->max_errors = max_errors;
-                bbio->mirror_num = mirror_num;
+
+        if (rw & REQ_WRITE) {
+                if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
+                                 BTRFS_BLOCK_GROUP_RAID10 |
+                                 BTRFS_BLOCK_GROUP_DUP)) {
+                        max_errors = 1;
+                }
         }
+
+        *bbio_ret = bbio;
+        bbio->num_stripes = num_stripes;
+        bbio->max_errors = max_errors;
+        bbio->mirror_num = mirror_num;
 out:
         free_extent_map(em);
-        return 0;
+        return ret;
 }
 
 int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
@@ -4284,7 +4226,7 @@ static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
         struct btrfs_fs_devices *fs_devices;
         int ret;
 
-        mutex_lock(&uuid_mutex);
+        BUG_ON(!mutex_is_locked(&uuid_mutex));
 
         fs_devices = root->fs_info->fs_devices->seed;
         while (fs_devices) {
@@ -4322,7 +4264,6 @@ static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
         fs_devices->seed = root->fs_info->fs_devices->seed;
         root->fs_info->fs_devices->seed = fs_devices;
 out:
-        mutex_unlock(&uuid_mutex);
         return ret;
 }
 
@@ -4465,6 +4406,9 @@ int btrfs_read_chunk_tree(struct btrfs_root *root)
         if (!path)
                 return -ENOMEM;
 
+        mutex_lock(&uuid_mutex);
+        lock_chunks(root);
+
         /* first we search for all of the device items, and then we
          * read in all of the chunk items.  This way we can create chunk
          * mappings that reference all of the devices that are afound
@@ -4515,6 +4459,9 @@ again:
         }
         ret = 0;
 error:
+        unlock_chunks(root);
+        mutex_unlock(&uuid_mutex);
+
         btrfs_free_path(path);
         return ret;
 }
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 6faec9dd1f93..19ac95048b88 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -279,7 +279,6 @@ int btrfs_recover_balance(struct btrfs_root *tree_root);
 int btrfs_pause_balance(struct btrfs_fs_info *fs_info);
 int btrfs_cancel_balance(struct btrfs_fs_info *fs_info);
 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset);
-int find_free_dev_extent(struct btrfs_trans_handle *trans,
-                         struct btrfs_device *device, u64 num_bytes,
+int find_free_dev_extent(struct btrfs_device *device, u64 num_bytes,
                          u64 *start, u64 *max_avail);
 #endif