]> git.karo-electronics.de Git - karo-tx-linux.git/blobdiff - fs/btrfs/disk-io.c
Btrfs: unplug all devices in the unplug call back
[karo-tx-linux.git] / fs / btrfs / disk-io.c
index d35ca6a3f513c3bc73786145dfde1917938d5d2d..0e8d31274c92733af7ea1de54fb61bdcb0bf888c 100644 (file)
 #include <linux/buffer_head.h> // for block_sync_page
 #include <linux/workqueue.h>
 #include <linux/kthread.h>
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,20)
 # include <linux/freezer.h>
-#else
-# include <linux/sched.h>
-#endif
 #include "crc32c.h"
 #include "ctree.h"
 #include "disk-io.h"
@@ -59,6 +55,11 @@ static int check_tree_block(struct btrfs_root *root, struct extent_buffer *buf)
 static struct extent_io_ops btree_extent_io_ops;
 static void end_workqueue_fn(struct btrfs_work *work);
 
+/*
+ * end_io_wq structs are used to do processing in task context when an IO is
+ * complete.  This is used during reads to verify checksums, and it is used
+ * by writes to insert metadata for new file extents after IO is complete.
+ */
 struct end_io_wq {
        struct bio *bio;
        bio_end_io_t *end_io;
@@ -70,16 +71,27 @@ struct end_io_wq {
        struct btrfs_work work;
 };
 
+/*
+ * async submit bios are used to offload expensive checksumming
+ * onto the worker threads.  They checksum file and metadata bios
+ * just before they are sent down the IO stack.
+ */
 struct async_submit_bio {
        struct inode *inode;
        struct bio *bio;
        struct list_head list;
-       extent_submit_bio_hook_t *submit_bio_hook;
+       extent_submit_bio_hook_t *submit_bio_start;
+       extent_submit_bio_hook_t *submit_bio_done;
        int rw;
        int mirror_num;
+       unsigned long bio_flags;
        struct btrfs_work work;
 };
 
+/*
+ * extents on the btree inode are pretty simple, there's one extent
+ * that covers the entire device
+ */
 struct extent_map *btree_get_extent(struct inode *inode, struct page *page,
                                    size_t page_offset, u64 start, u64 len,
                                    int create)
@@ -105,6 +117,7 @@ struct extent_map *btree_get_extent(struct inode *inode, struct page *page,
        }
        em->start = 0;
        em->len = (u64)-1;
+       em->block_len = (u64)-1;
        em->block_start = 0;
        em->bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
 
@@ -155,6 +168,10 @@ void btrfs_csum_final(u32 crc, char *result)
        *(__le32 *)result = ~cpu_to_le32(crc);
 }
 
+/*
+ * compute the csum for a btree block, and either verify it or write it
+ * into the csum field of the block.
+ */
 static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
                           int verify)
 {
@@ -208,6 +225,12 @@ static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
        return 0;
 }
 
+/*
+ * we can't consider a given block up to date unless the transid of the
+ * block matches the transid in the parent node's pointer.  This is how we
+ * detect blocks that either didn't get written at all or got written
+ * in the wrong place.
+ */
 static int verify_parent_transid(struct extent_io_tree *io_tree,
                                 struct extent_buffer *eb, u64 parent_transid)
 {
@@ -232,9 +255,12 @@ out:
        unlock_extent(io_tree, eb->start, eb->start + eb->len - 1,
                      GFP_NOFS);
        return ret;
-
 }
 
+/*
+ * helper to read a given tree block, doing retries as required when
+ * the checksums don't match and we have alternate mirrors to try.
+ */
 static int btree_read_extent_buffer_pages(struct btrfs_root *root,
                                          struct extent_buffer *eb,
                                          u64 start, u64 parent_transid)
@@ -264,6 +290,10 @@ printk("read extent buffer pages failed with ret %d mirror no %d\n", ret, mirror
        return -EIO;
 }
 
+/*
+ * checksum a dirty tree block before IO.  This has extra checks to make
+ * sure we only fill in the checksum field in the first page of a multi-page block
+ */
 int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
 {
        struct extent_io_tree *tree;
@@ -315,6 +345,25 @@ out:
        return 0;
 }
 
+static int check_tree_block_fsid(struct btrfs_root *root,
+                                struct extent_buffer *eb)
+{
+       struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
+       u8 fsid[BTRFS_UUID_SIZE];
+       int ret = 1;
+
+       read_extent_buffer(eb, fsid, (unsigned long)btrfs_header_fsid(eb),
+                          BTRFS_FSID_SIZE);
+       while (fs_devices) {
+               if (!memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE)) {
+                       ret = 0;
+                       break;
+               }
+               fs_devices = fs_devices->seed;
+       }
+       return ret;
+}
+
 int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
                               struct extent_state *state)
 {
@@ -352,9 +401,7 @@ int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
                ret = -EIO;
                goto err;
        }
-       if (memcmp_extent_buffer(eb, root->fs_info->fsid,
-                                (unsigned long)btrfs_header_fsid(eb),
-                                BTRFS_FSID_SIZE)) {
+       if (check_tree_block_fsid(root, eb)) {
                printk("bad fsid on block %Lu\n", eb->start);
                ret = -EIO;
                goto err;
@@ -373,21 +420,11 @@ out:
        return ret;
 }
 
-#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
 static void end_workqueue_bio(struct bio *bio, int err)
-#else
-static int end_workqueue_bio(struct bio *bio,
-                                  unsigned int bytes_done, int err)
-#endif
 {
        struct end_io_wq *end_io_wq = bio->bi_private;
        struct btrfs_fs_info *fs_info;
 
-#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
-       if (bio->bi_size)
-               return 1;
-#endif
-
        fs_info = end_io_wq->info;
        end_io_wq->error = err;
        end_io_wq->work.func = end_workqueue_fn;
@@ -397,10 +434,6 @@ static int end_workqueue_bio(struct bio *bio,
                                   &end_io_wq->work);
        else
                btrfs_queue_worker(&fs_info->endio_workers, &end_io_wq->work);
-
-#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
-       return 0;
-#endif
 }
 
 int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
@@ -437,7 +470,18 @@ int btrfs_congested_async(struct btrfs_fs_info *info, int iodone)
                btrfs_async_submit_limit(info);
 }
 
-static void run_one_async_submit(struct btrfs_work *work)
+static void run_one_async_start(struct btrfs_work *work)
+{
+       struct btrfs_fs_info *fs_info;
+       struct async_submit_bio *async;
+
+       async = container_of(work, struct  async_submit_bio, work);
+       fs_info = BTRFS_I(async->inode)->root->fs_info;
+       async->submit_bio_start(async->inode, async->rw, async->bio,
+                              async->mirror_num, async->bio_flags);
+}
+
+static void run_one_async_done(struct btrfs_work *work)
 {
        struct btrfs_fs_info *fs_info;
        struct async_submit_bio *async;
@@ -455,14 +499,23 @@ static void run_one_async_submit(struct btrfs_work *work)
            waitqueue_active(&fs_info->async_submit_wait))
                wake_up(&fs_info->async_submit_wait);
 
-       async->submit_bio_hook(async->inode, async->rw, async->bio,
-                              async->mirror_num);
+       async->submit_bio_done(async->inode, async->rw, async->bio,
+                              async->mirror_num, async->bio_flags);
+}
+
+static void run_one_async_free(struct btrfs_work *work)
+{
+       struct async_submit_bio *async;
+
+       async = container_of(work, struct  async_submit_bio, work);
        kfree(async);
 }
 
 int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
                        int rw, struct bio *bio, int mirror_num,
-                       extent_submit_bio_hook_t *submit_bio_hook)
+                       unsigned long bio_flags,
+                       extent_submit_bio_hook_t *submit_bio_start,
+                       extent_submit_bio_hook_t *submit_bio_done)
 {
        struct async_submit_bio *async;
        int limit = btrfs_async_submit_limit(fs_info);
@@ -475,9 +528,22 @@ int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
        async->rw = rw;
        async->bio = bio;
        async->mirror_num = mirror_num;
-       async->submit_bio_hook = submit_bio_hook;
-       async->work.func = run_one_async_submit;
+       async->submit_bio_start = submit_bio_start;
+       async->submit_bio_done = submit_bio_done;
+
+       async->work.func = run_one_async_start;
+       async->work.ordered_func = run_one_async_done;
+       async->work.ordered_free = run_one_async_free;
+
        async->work.flags = 0;
+       async->bio_flags = bio_flags;
+
+       while(atomic_read(&fs_info->async_submit_draining) &&
+             atomic_read(&fs_info->nr_async_submits)) {
+               wait_event(fs_info->async_submit_wait,
+                          (atomic_read(&fs_info->nr_async_submits) == 0));
+       }
+
        atomic_inc(&fs_info->nr_async_submits);
        btrfs_queue_worker(&fs_info->workers, &async->work);
 
@@ -490,6 +556,13 @@ int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
                           (atomic_read(&fs_info->nr_async_bios) < limit),
                           HZ/10);
        }
+
+       while(atomic_read(&fs_info->async_submit_draining) &&
+             atomic_read(&fs_info->nr_async_submits)) {
+               wait_event(fs_info->async_submit_wait,
+                          (atomic_read(&fs_info->nr_async_submits) == 0));
+       }
+
        return 0;
 }
 
@@ -509,48 +582,52 @@ static int btree_csum_one_bio(struct bio *bio)
        return 0;
 }
 
-static int __btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
-                                int mirror_num)
+static int __btree_submit_bio_start(struct inode *inode, int rw,
+                                   struct bio *bio, int mirror_num,
+                                   unsigned long bio_flags)
 {
-       struct btrfs_root *root = BTRFS_I(inode)->root;
-       u64 offset;
-       int ret;
-
-       offset = bio->bi_sector << 9;
-
        /*
         * when we're called for a write, we're already in the async
         * submission context.  Just jump into btrfs_map_bio
         */
-       if (rw & (1 << BIO_RW)) {
-               btree_csum_one_bio(bio);
-               return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio,
-                                    mirror_num, 1);
-       }
+       btree_csum_one_bio(bio);
+       return 0;
+}
 
+static int __btree_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
+                                int mirror_num, unsigned long bio_flags)
+{
        /*
-        * called for a read, do the setup so that checksum validation
-        * can happen in the async kernel threads
+        * when we're called for a write, we're already in the async
+        * submission context.  Just jump into btrfs_map_bio
         */
-       ret = btrfs_bio_wq_end_io(root->fs_info, bio, 1);
-       BUG_ON(ret);
-
        return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, mirror_num, 1);
 }
 
 static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
-                                int mirror_num)
+                                int mirror_num, unsigned long bio_flags)
 {
        /*
         * kthread helpers are used to submit writes so that checksumming
         * can happen in parallel across all CPUs
         */
        if (!(rw & (1 << BIO_RW))) {
-               return __btree_submit_bio_hook(inode, rw, bio, mirror_num);
+               int ret;
+               /*
+                * called for a read, do the setup so that checksum validation
+                * can happen in the async kernel threads
+                */
+               ret = btrfs_bio_wq_end_io(BTRFS_I(inode)->root->fs_info,
+                                         bio, 1);
+               BUG_ON(ret);
+
+               return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio,
+                                    mirror_num, 0);
        }
        return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
-                                  inode, rw, bio, mirror_num,
-                                  __btree_submit_bio_hook);
+                                  inode, rw, bio, mirror_num, 0,
+                                  __btree_submit_bio_start,
+                                  __btree_submit_bio_done);
 }
 
 static int btree_writepage(struct page *page, struct writeback_control *wbc)
@@ -574,7 +651,7 @@ static int btree_writepages(struct address_space *mapping,
        if (wbc->sync_mode == WB_SYNC_NONE) {
                u64 num_dirty;
                u64 start = 0;
-               unsigned long thresh = 8 * 1024 * 1024;
+               unsigned long thresh = 32 * 1024 * 1024;
 
                if (wbc->for_kupdate)
                        return 0;
@@ -708,7 +785,7 @@ struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
 int btrfs_write_tree_block(struct extent_buffer *buf)
 {
        return btrfs_fdatawrite_range(buf->first_page->mapping, buf->start,
-                                     buf->start + buf->len - 1, WB_SYNC_NONE);
+                                     buf->start + buf->len - 1, WB_SYNC_ALL);
 }
 
 int btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
@@ -761,7 +838,6 @@ static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
                        u64 objectid)
 {
        root->node = NULL;
-       root->inode = NULL;
        root->commit_root = NULL;
        root->ref_tree = NULL;
        root->sectorsize = sectorsize;
@@ -801,6 +877,12 @@ static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
        root->defrag_running = 0;
        root->defrag_level = 0;
        root->root_key.objectid = objectid;
+       root->anon_super.s_root = NULL;
+       root->anon_super.s_dev = 0;
+       INIT_LIST_HEAD(&root->anon_super.s_list);
+       INIT_LIST_HEAD(&root->anon_super.s_instances);
+       init_rwsem(&root->anon_super.s_umount);
+
        return 0;
 }
 
@@ -811,6 +893,7 @@ static int find_and_setup_root(struct btrfs_root *tree_root,
 {
        int ret;
        u32 blocksize;
+       u64 generation;
 
        __setup_root(tree_root->nodesize, tree_root->leafsize,
                     tree_root->sectorsize, tree_root->stripesize,
@@ -819,9 +902,10 @@ static int find_and_setup_root(struct btrfs_root *tree_root,
                                   &root->root_item, &root->root_key);
        BUG_ON(ret);
 
+       generation = btrfs_root_generation(&root->root_item);
        blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
        root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
-                                    blocksize, 0);
+                                    blocksize, generation);
        BUG_ON(!root->node);
        return 0;
 }
@@ -908,6 +992,7 @@ struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
        struct btrfs_path *path;
        struct extent_buffer *l;
        u64 highest_inode;
+       u64 generation;
        u32 blocksize;
        int ret = 0;
 
@@ -949,9 +1034,10 @@ out:
                kfree(root);
                return ERR_PTR(ret);
        }
+       generation = btrfs_root_generation(&root->root_item);
        blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
        root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
-                                    blocksize, 0);
+                                    blocksize, generation);
        BUG_ON(!root->node);
 insert:
        if (location->objectid != BTRFS_TREE_LOG_OBJECTID) {
@@ -1003,6 +1089,9 @@ struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
        root = btrfs_read_fs_root_no_radix(fs_info->tree_root, location);
        if (IS_ERR(root))
                return root;
+
+       set_anon_super(&root->anon_super, NULL);
+
        ret = radix_tree_insert(&fs_info->fs_roots_radix,
                                (unsigned long)root->root_key.objectid,
                                root);
@@ -1011,10 +1100,12 @@ struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
                kfree(root);
                return ERR_PTR(ret);
        }
-       ret = btrfs_find_dead_roots(fs_info->tree_root,
-                                   root->root_key.objectid, root);
-       BUG_ON(ret);
-
+       if (!(fs_info->sb->s_flags & MS_RDONLY)) {
+               ret = btrfs_find_dead_roots(fs_info->tree_root,
+                                           root->root_key.objectid, root);
+               BUG_ON(ret);
+               btrfs_orphan_cleanup(root);
+       }
        return root;
 }
 
@@ -1038,7 +1129,7 @@ struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
                kfree(root);
                return ERR_PTR(ret);
        }
-
+#if 0
        ret = btrfs_sysfs_add_root(root);
        if (ret) {
                free_extent_buffer(root->node);
@@ -1046,6 +1137,7 @@ struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
                kfree(root);
                return ERR_PTR(ret);
        }
+#endif
        root->in_sysfs = 1;
        return root;
 }
@@ -1075,11 +1167,11 @@ static int btrfs_congested_fn(void *congested_data, int bdi_bits)
        struct list_head *cur;
        struct btrfs_device *device;
        struct backing_dev_info *bdi;
-
+#if 0
        if ((bdi_bits & (1 << BDI_write_congested)) &&
            btrfs_congested_async(info, 0))
                return 1;
-
+#endif
        list_for_each(cur, &info->fs_devices->devices) {
                device = list_entry(cur, struct btrfs_device, dev_list);
                if (!device->bdev)
@@ -1122,7 +1214,7 @@ void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
        u64 offset;
 
        /* the generic O_DIRECT read code does this */
-       if (!page) {
+       if (1 || !page) {
                __unplug_io_fn(bdi, page);
                return;
        }
@@ -1137,6 +1229,16 @@ void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
                return;
 
        inode = mapping->host;
+
+       /*
+        * don't do the expensive searching for a small number of
+        * devices
+        */
+       if (BTRFS_I(inode)->root->fs_info->fs_devices->open_devices <= 2) {
+               __unplug_io_fn(bdi, page);
+               return;
+       }
+
        offset = page_offset(page);
 
        em_tree = &BTRFS_I(inode)->extent_tree;
@@ -1161,9 +1263,7 @@ void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
 
 static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
 {
-#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
        bdi_init(bdi);
-#endif
        bdi->ra_pages   = default_backing_dev_info.ra_pages;
        bdi->state              = 0;
        bdi->capabilities       = default_backing_dev_info.capabilities;
@@ -1242,11 +1342,7 @@ static void end_workqueue_fn(struct btrfs_work *work)
        bio->bi_private = end_io_wq->private;
        bio->bi_end_io = end_io_wq->end_io;
        kfree(end_io_wq);
-#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
-       bio_endio(bio, bio->bi_size, error);
-#else
        bio_endio(bio, error);
-#endif
 }
 
 static int cleaner_kthread(void *arg)
@@ -1342,6 +1438,8 @@ struct btrfs_root *open_ctree(struct super_block *sb,
        u32 leafsize;
        u32 blocksize;
        u32 stripesize;
+       u64 generation;
+       struct btrfs_key location;
        struct buffer_head *bh;
        struct btrfs_root *extent_root = kzalloc(sizeof(struct btrfs_root),
                                                 GFP_NOFS);
@@ -1360,7 +1458,8 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 
        struct btrfs_super_block *disk_super;
 
-       if (!extent_root || !tree_root || !fs_info) {
+       if (!extent_root || !tree_root || !fs_info ||
+           !chunk_root || !dev_root) {
                err = -ENOMEM;
                goto fail;
        }
@@ -1384,6 +1483,8 @@ struct btrfs_root *open_ctree(struct super_block *sb,
        INIT_LIST_HEAD(&fs_info->space_info);
        btrfs_mapping_init(&fs_info->mapping_tree);
        atomic_set(&fs_info->nr_async_submits, 0);
+       atomic_set(&fs_info->async_delalloc_pages, 0);
+       atomic_set(&fs_info->async_submit_draining, 0);
        atomic_set(&fs_info->nr_async_bios, 0);
        atomic_set(&fs_info->throttles, 0);
        atomic_set(&fs_info->throttle_gen, 0);
@@ -1394,6 +1495,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
        fs_info->btree_inode = new_inode(sb);
        fs_info->btree_inode->i_ino = 1;
        fs_info->btree_inode->i_nlink = 1;
+
        fs_info->thread_pool_size = min(num_online_cpus() + 2, 8);
 
        INIT_LIST_HEAD(&fs_info->ordered_extents);
@@ -1430,6 +1532,10 @@ struct btrfs_root *open_ctree(struct super_block *sb,
                             fs_info->btree_inode->i_mapping, GFP_NOFS);
        fs_info->do_barriers = 1;
 
+       INIT_LIST_HEAD(&fs_info->dead_reloc_roots);
+       btrfs_leaf_ref_tree_init(&fs_info->reloc_ref_tree);
+       btrfs_leaf_ref_tree_init(&fs_info->shared_ref_tree);
+
        BTRFS_I(fs_info->btree_inode)->root = tree_root;
        memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
               sizeof(struct btrfs_key));
@@ -1438,11 +1544,13 @@ struct btrfs_root *open_ctree(struct super_block *sb,
        mutex_init(&fs_info->trans_mutex);
        mutex_init(&fs_info->tree_log_mutex);
        mutex_init(&fs_info->drop_mutex);
-       mutex_init(&fs_info->alloc_mutex);
+       mutex_init(&fs_info->extent_ins_mutex);
+       mutex_init(&fs_info->pinned_mutex);
        mutex_init(&fs_info->chunk_mutex);
        mutex_init(&fs_info->transaction_kthread_mutex);
        mutex_init(&fs_info->cleaner_mutex);
        mutex_init(&fs_info->volume_mutex);
+       mutex_init(&fs_info->tree_reloc_mutex);
        init_waitqueue_head(&fs_info->transaction_throttle);
        init_waitqueue_head(&fs_info->transaction_wait);
        init_waitqueue_head(&fs_info->async_submit_wait);
@@ -1477,9 +1585,11 @@ struct btrfs_root *open_ctree(struct super_block *sb,
        if (!btrfs_super_root(disk_super))
                goto fail_sb_buffer;
 
-       err = btrfs_parse_options(tree_root, options);
-       if (err)
+       ret = btrfs_parse_options(tree_root, options);
+       if (ret) {
+               err = ret;
                goto fail_sb_buffer;
+       }
 
        /*
         * we need to start all the end_io workers up front because the
@@ -1488,6 +1598,10 @@ struct btrfs_root *open_ctree(struct super_block *sb,
         */
        btrfs_init_workers(&fs_info->workers, "worker",
                           fs_info->thread_pool_size);
+
+       btrfs_init_workers(&fs_info->delalloc_workers, "delalloc",
+                          fs_info->thread_pool_size);
+
        btrfs_init_workers(&fs_info->submit_workers, "submit",
                           min_t(u64, fs_devices->num_devices,
                           fs_info->thread_pool_size));
@@ -1498,13 +1612,11 @@ struct btrfs_root *open_ctree(struct super_block *sb,
         */
        fs_info->submit_workers.idle_thresh = 64;
 
-       /* fs_info->workers is responsible for checksumming file data
-        * blocks and metadata.  Using a larger idle thresh allows each
-        * worker thread to operate on things in roughly the order they
-        * were sent by the writeback daemons, improving overall locality
-        * of the IO going down the pipe.
-        */
-       fs_info->workers.idle_thresh = 128;
+       fs_info->workers.idle_thresh = 16;
+       fs_info->workers.ordered = 1;
+
+       fs_info->delalloc_workers.idle_thresh = 2;
+       fs_info->delalloc_workers.ordered = 1;
 
        btrfs_init_workers(&fs_info->fixup_workers, "fixup", 1);
        btrfs_init_workers(&fs_info->endio_workers, "endio",
@@ -1521,24 +1633,15 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 
        btrfs_start_workers(&fs_info->workers, 1);
        btrfs_start_workers(&fs_info->submit_workers, 1);
+       btrfs_start_workers(&fs_info->delalloc_workers, 1);
        btrfs_start_workers(&fs_info->fixup_workers, 1);
        btrfs_start_workers(&fs_info->endio_workers, fs_info->thread_pool_size);
        btrfs_start_workers(&fs_info->endio_write_workers,
                            fs_info->thread_pool_size);
 
-       err = -EINVAL;
-       if (btrfs_super_num_devices(disk_super) > fs_devices->open_devices) {
-               printk("Btrfs: wanted %llu devices, but found %llu\n",
-                      (unsigned long long)btrfs_super_num_devices(disk_super),
-                      (unsigned long long)fs_devices->open_devices);
-               if (btrfs_test_opt(tree_root, DEGRADED))
-                       printk("continuing in degraded mode\n");
-               else {
-                       goto fail_sb_buffer;
-               }
-       }
-
        fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
+       fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages,
+                                   4 * 1024 * 1024 / PAGE_CACHE_SIZE);
 
        nodesize = btrfs_super_nodesize(disk_super);
        leafsize = btrfs_super_leafsize(disk_super);
@@ -1569,13 +1672,14 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 
        blocksize = btrfs_level_size(tree_root,
                                     btrfs_super_chunk_root_level(disk_super));
+       generation = btrfs_super_chunk_root_generation(disk_super);
 
        __setup_root(nodesize, leafsize, sectorsize, stripesize,
                     chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
 
        chunk_root->node = read_tree_block(chunk_root,
                                           btrfs_super_chunk_root(disk_super),
-                                          blocksize, 0);
+                                          blocksize, generation);
        BUG_ON(!chunk_root->node);
 
        read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
@@ -1585,19 +1689,22 @@ struct btrfs_root *open_ctree(struct super_block *sb,
        mutex_lock(&fs_info->chunk_mutex);
        ret = btrfs_read_chunk_tree(chunk_root);
        mutex_unlock(&fs_info->chunk_mutex);
-       BUG_ON(ret);
+       if (ret) {
+               printk("btrfs: failed to read chunk tree on %s\n", sb->s_id);
+               goto fail_chunk_root;
+       }
 
        btrfs_close_extra_devices(fs_devices);
 
        blocksize = btrfs_level_size(tree_root,
                                     btrfs_super_root_level(disk_super));
-
+       generation = btrfs_super_generation(disk_super);
 
        tree_root->node = read_tree_block(tree_root,
                                          btrfs_super_root(disk_super),
-                                         blocksize, 0);
+                                         blocksize, generation);
        if (!tree_root->node)
-               goto fail_sb_buffer;
+               goto fail_chunk_root;
 
 
        ret = find_and_setup_root(tree_root, fs_info,
@@ -1615,7 +1722,8 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 
        btrfs_read_block_groups(extent_root);
 
-       fs_info->generation = btrfs_super_generation(disk_super) + 1;
+       fs_info->generation = generation + 1;
+       fs_info->last_trans_committed = generation;
        fs_info->data_alloc_profile = (u64)-1;
        fs_info->metadata_alloc_profile = (u64)-1;
        fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
@@ -1630,6 +1738,9 @@ struct btrfs_root *open_ctree(struct super_block *sb,
        if (!fs_info->transaction_kthread)
                goto fail_cleaner;
 
+       if (sb->s_flags & MS_RDONLY)
+               goto read_fs_root;
+
        if (btrfs_super_log_root(disk_super) != 0) {
                u32 blocksize;
                u64 bytenr = btrfs_super_log_root(disk_super);
@@ -1645,11 +1756,23 @@ struct btrfs_root *open_ctree(struct super_block *sb,
                             log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
 
                log_tree_root->node = read_tree_block(tree_root, bytenr,
-                                                     blocksize, 0);
+                                                     blocksize,
+                                                     generation + 1);
                ret = btrfs_recover_log_trees(log_tree_root);
                BUG_ON(ret);
        }
-       fs_info->last_trans_committed = btrfs_super_generation(disk_super);
+
+       ret = btrfs_cleanup_reloc_trees(tree_root);
+       BUG_ON(ret);
+
+       location.objectid = BTRFS_FS_TREE_OBJECTID;
+       location.type = BTRFS_ROOT_ITEM_KEY;
+       location.offset = (u64)-1;
+
+read_fs_root:
+       fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location);
+       if (!fs_info->fs_root)
+               goto fail_cleaner;
        return tree_root;
 
 fail_cleaner:
@@ -1658,9 +1781,12 @@ fail_extent_root:
        free_extent_buffer(extent_root->node);
 fail_tree_root:
        free_extent_buffer(tree_root->node);
+fail_chunk_root:
+       free_extent_buffer(chunk_root->node);
 fail_sys_array:
 fail_sb_buffer:
        btrfs_stop_workers(&fs_info->fixup_workers);
+       btrfs_stop_workers(&fs_info->delalloc_workers);
        btrfs_stop_workers(&fs_info->workers);
        btrfs_stop_workers(&fs_info->endio_workers);
        btrfs_stop_workers(&fs_info->endio_write_workers);
@@ -1673,10 +1799,10 @@ fail:
 
        kfree(extent_root);
        kfree(tree_root);
-#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
        bdi_destroy(&fs_info->bdi);
-#endif
        kfree(fs_info);
+       kfree(chunk_root);
+       kfree(dev_root);
        return ERR_PTR(err);
 }
 
@@ -1727,9 +1853,10 @@ int write_all_supers(struct btrfs_root *root)
                        total_errors++;
                        continue;
                }
-               if (!dev->in_fs_metadata)
+               if (!dev->in_fs_metadata || !dev->writeable)
                        continue;
 
+               btrfs_set_stack_device_generation(dev_item, 0);
                btrfs_set_stack_device_type(dev_item, dev->type);
                btrfs_set_stack_device_id(dev_item, dev->devid);
                btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes);
@@ -1738,6 +1865,7 @@ int write_all_supers(struct btrfs_root *root)
                btrfs_set_stack_device_io_width(dev_item, dev->io_width);
                btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
                memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
+               memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
                flags = btrfs_super_flags(sb);
                btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
 
@@ -1785,7 +1913,7 @@ int write_all_supers(struct btrfs_root *root)
                dev = list_entry(cur, struct btrfs_device, dev_list);
                if (!dev->bdev)
                        continue;
-               if (!dev->in_fs_metadata)
+               if (!dev->in_fs_metadata || !dev->writeable)
                        continue;
 
                BUG_ON(!dev->pending_io);
@@ -1832,10 +1960,14 @@ int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
 {
        radix_tree_delete(&fs_info->fs_roots_radix,
                          (unsigned long)root->root_key.objectid);
+       if (root->anon_super.s_dev) {
+               down_write(&root->anon_super.s_umount);
+               kill_anon_super(&root->anon_super);
+       }
+#if 0
        if (root->in_sysfs)
                btrfs_sysfs_del_root(root);
-       if (root->inode)
-               iput(root->inode);
+#endif
        if (root->node)
                free_extent_buffer(root->node);
        if (root->commit_root)
@@ -1864,28 +1996,69 @@ static int del_fs_roots(struct btrfs_fs_info *fs_info)
        return 0;
 }
 
-int close_ctree(struct btrfs_root *root)
+int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
 {
+       u64 root_objectid = 0;
+       struct btrfs_root *gang[8];
+       int i;
        int ret;
-       struct btrfs_trans_handle *trans;
-       struct btrfs_fs_info *fs_info = root->fs_info;
 
-       fs_info->closing = 1;
-       smp_mb();
+       while (1) {
+               ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
+                                            (void **)gang, root_objectid,
+                                            ARRAY_SIZE(gang));
+               if (!ret)
+                       break;
+               for (i = 0; i < ret; i++) {
+                       root_objectid = gang[i]->root_key.objectid;
+                       ret = btrfs_find_dead_roots(fs_info->tree_root,
+                                                   root_objectid, gang[i]);
+                       BUG_ON(ret);
+                       btrfs_orphan_cleanup(gang[i]);
+               }
+               root_objectid++;
+       }
+       return 0;
+}
 
-       kthread_stop(root->fs_info->transaction_kthread);
-       kthread_stop(root->fs_info->cleaner_kthread);
+int btrfs_commit_super(struct btrfs_root *root)
+{
+       struct btrfs_trans_handle *trans;
+       int ret;
 
+       mutex_lock(&root->fs_info->cleaner_mutex);
        btrfs_clean_old_snapshots(root);
+       mutex_unlock(&root->fs_info->cleaner_mutex);
        trans = btrfs_start_transaction(root, 1);
        ret = btrfs_commit_transaction(trans, root);
-       /* run commit again to  drop the original snapshot */
+       BUG_ON(ret);
+       /* run commit again to drop the original snapshot */
        trans = btrfs_start_transaction(root, 1);
        btrfs_commit_transaction(trans, root);
        ret = btrfs_write_and_wait_transaction(NULL, root);
        BUG_ON(ret);
 
-       write_ctree_super(NULL, root);
+       ret = write_ctree_super(NULL, root);
+       return ret;
+}
+
+int close_ctree(struct btrfs_root *root)
+{
+       struct btrfs_fs_info *fs_info = root->fs_info;
+       int ret;
+
+       fs_info->closing = 1;
+       smp_mb();
+
+       kthread_stop(root->fs_info->transaction_kthread);
+       kthread_stop(root->fs_info->cleaner_kthread);
+
+       if (!(fs_info->sb->s_flags & MS_RDONLY)) {
+               ret =  btrfs_commit_super(root);
+               if (ret) {
+                       printk("btrfs: commit super returns %d\n", ret);
+               }
+       }
 
        if (fs_info->delalloc_bytes) {
                printk("btrfs: at unmount delalloc count %Lu\n",
@@ -1909,20 +2082,18 @@ int close_ctree(struct btrfs_root *root)
                free_extent_buffer(root->fs_info->dev_root->node);
 
        btrfs_free_block_groups(root->fs_info);
-       fs_info->closing = 2;
-       del_fs_roots(fs_info);
 
-       filemap_write_and_wait(fs_info->btree_inode->i_mapping);
+       del_fs_roots(fs_info);
 
-       truncate_inode_pages(fs_info->btree_inode->i_mapping, 0);
+       iput(fs_info->btree_inode);
 
        btrfs_stop_workers(&fs_info->fixup_workers);
+       btrfs_stop_workers(&fs_info->delalloc_workers);
        btrfs_stop_workers(&fs_info->workers);
        btrfs_stop_workers(&fs_info->endio_workers);
        btrfs_stop_workers(&fs_info->endio_write_workers);
        btrfs_stop_workers(&fs_info->submit_workers);
 
-       iput(fs_info->btree_inode);
 #if 0
        while(!list_empty(&fs_info->hashers)) {
                struct btrfs_hasher *hasher;
@@ -1936,9 +2107,7 @@ int close_ctree(struct btrfs_root *root)
        btrfs_close_devices(fs_info->fs_devices);
        btrfs_mapping_tree_free(&fs_info->mapping_tree);
 
-#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
        bdi_destroy(&fs_info->bdi);
-#endif
 
        kfree(fs_info->extent_root);
        kfree(fs_info->tree_root);
@@ -1993,7 +2162,7 @@ void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
        struct extent_io_tree *tree;
        u64 num_dirty;
        u64 start = 0;
-       unsigned long thresh = 96 * 1024 * 1024;
+       unsigned long thresh = 32 * 1024 * 1024;
        tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
 
        if (current_is_pdflush() || current->flags & PF_MEMALLOC)