btrfs-progs: remove old debugging statement
[platform/upstream/btrfs-progs.git] / disk-io.c
index 1afe5a6..408b2d5 100644 (file)
--- a/disk-io.c
+++ b/disk-io.c
@@ -18,6 +18,7 @@
 
 #define _XOPEN_SOURCE 600
 #define __USE_XOPEN2K
+#define _GNU_SOURCE 1
 #include <stdio.h>
 #include <stdlib.h>
 #include <sys/types.h>
 #include "transaction.h"
 #include "crc32c.h"
 #include "utils.h"
+#include "print-tree.h"
 
-int btrfs_map_bh_to_logical(struct btrfs_root *root, struct extent_buffer *buf,
-                           u64 logical)
-{
-       u64 physical;
-       u64 length;
-       struct btrfs_device *device;
-       int ret;
-
-       ret = btrfs_map_block(&root->fs_info->mapping_tree, logical, &physical,
-                             &length, &device);
-       BUG_ON(ret);
-       buf->fd = device->fd;
-       buf->dev_bytenr = physical;
-       return 0;
-}
+static int close_all_devices(struct btrfs_fs_info *fs_info);
 
 static int check_tree_block(struct btrfs_root *root, struct extent_buffer *buf)
 {
-       if (buf->start != btrfs_header_bytenr(buf))
-               BUG();
 
-       if (memcmp_extent_buffer(buf, root->fs_info->fsid,
-                                (unsigned long)btrfs_header_fsid(buf),
-                                BTRFS_FSID_SIZE))
-               BUG();
-       return 0;
+       struct btrfs_fs_devices *fs_devices;
+       int ret = 1;
+
+       if (buf->start != btrfs_header_bytenr(buf)) {
+               printk("Check tree block failed, want=%Lu, have=%Lu\n",
+                      buf->start, btrfs_header_bytenr(buf));
+               return ret;
+       }
+
+       fs_devices = root->fs_info->fs_devices;
+       while (fs_devices) {
+               if (!memcmp_extent_buffer(buf, fs_devices->fsid,
+                                         (unsigned long)btrfs_header_fsid(buf),
+                                         BTRFS_FSID_SIZE)) {
+                       ret = 0;
+                       break;
+               }
+               fs_devices = fs_devices->seed;
+       }
+       return ret;
 }
 
 u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len)
@@ -71,28 +72,44 @@ void btrfs_csum_final(u32 crc, char *result)
        *(__le32 *)result = ~cpu_to_le32(crc);
 }
 
-static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
-                          int verify)
+int csum_tree_block_size(struct extent_buffer *buf, u16 csum_size,
+                        int verify)
 {
-       char result[BTRFS_CRC32_SIZE];
+       char *result;
        u32 len;
        u32 crc = ~(u32)0;
 
+       result = malloc(csum_size * sizeof(char));
+       if (!result)
+               return 1;
+
        len = buf->len - BTRFS_CSUM_SIZE;
        crc = crc32c(crc, buf->data + BTRFS_CSUM_SIZE, len);
        btrfs_csum_final(crc, result);
 
        if (verify) {
-               if (memcmp_extent_buffer(buf, result, 0, BTRFS_CRC32_SIZE)) {
-                       printk("checksum verify failed on %llu\n", buf->start);
+               if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
+                       printk("checksum verify failed on %llu wanted %X "
+                              "found %X\n", (unsigned long long)buf->start,
+                              *((int *)result), *((char *)buf->data));
+                       free(result);
                        return 1;
                }
        } else {
-               write_extent_buffer(buf, result, 0, BTRFS_CRC32_SIZE);
+               write_extent_buffer(buf, result, 0, csum_size);
        }
+       free(result);
        return 0;
 }
 
+int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
+                   int verify)
+{
+       u16 csum_size =
+               btrfs_super_csum_size(&root->fs_info->super_copy);
+       return csum_tree_block_size(buf, csum_size, verify);
+}
+
 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
                                            u64 bytenr, u32 blocksize)
 {
@@ -107,42 +124,167 @@ struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
                                   blocksize);
 }
 
-int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize)
+int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
+                        u64 parent_transid)
 {
+       int ret;
+       struct extent_buffer *eb;
+       u64 length;
+       struct btrfs_multi_bio *multi = NULL;
+       struct btrfs_device *device;
+
+       eb = btrfs_find_tree_block(root, bytenr, blocksize);
+       if (eb && btrfs_buffer_uptodate(eb, parent_transid)) {
+               free_extent_buffer(eb);
+               return 0;
+       }
+
+       length = blocksize;
+       ret = btrfs_map_block(&root->fs_info->mapping_tree, READ,
+                             bytenr, &length, &multi, 0);
+       BUG_ON(ret);
+       device = multi->stripes[0].dev;
+       device->total_ios++;
+       blocksize = min(blocksize, (u32)(64 * 1024));
+       readahead(device->fd, multi->stripes[0].physical, blocksize);
+       kfree(multi);
        return 0;
 }
 
+static int verify_parent_transid(struct extent_io_tree *io_tree,
+                                struct extent_buffer *eb, u64 parent_transid,
+                                int ignore)
+{
+       int ret;
+
+       if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
+               return 0;
+
+       if (extent_buffer_uptodate(eb) &&
+           btrfs_header_generation(eb) == parent_transid) {
+               ret = 0;
+               goto out;
+       }
+       printk("parent transid verify failed on %llu wanted %llu found %llu\n",
+              (unsigned long long)eb->start,
+              (unsigned long long)parent_transid,
+              (unsigned long long)btrfs_header_generation(eb));
+       if (ignore) {
+               printk("Ignoring transid failure\n");
+               return 0;
+       }
+
+       ret = 1;
+out:
+       clear_extent_buffer_uptodate(io_tree, eb);
+       return ret;
+
+}
+
+
 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
-                                    u32 blocksize)
+                                    u32 blocksize, u64 parent_transid)
 {
        int ret;
        struct extent_buffer *eb;
+       u64 length;
+       u64 best_transid = 0;
+       struct btrfs_multi_bio *multi = NULL;
+       struct btrfs_device *device;
+       int mirror_num = 0;
+       int good_mirror = 0;
+       int num_copies;
+       int ignore = 0;
 
        eb = btrfs_find_create_tree_block(root, bytenr, blocksize);
        if (!eb)
                return NULL;
-       if (!btrfs_buffer_uptodate(eb)) {
-               btrfs_map_bh_to_logical(root, eb, eb->start);
-               ret = read_extent_from_disk(eb);
+
+       if (btrfs_buffer_uptodate(eb, parent_transid))
+               return eb;
+
+       length = blocksize;
+       while (1) {
+               ret = btrfs_map_block(&root->fs_info->mapping_tree, READ,
+                                     eb->start, &length, &multi, mirror_num);
                if (ret) {
-                       free_extent_buffer(eb);
-                       return NULL;
+                       printk("Couldn't map the block %Lu\n", bytenr);
+                       break;
+               }
+               device = multi->stripes[0].dev;
+               eb->fd = device->fd;
+               device->total_ios++;
+               eb->dev_bytenr = multi->stripes[0].physical;
+               kfree(multi);
+               ret = read_extent_from_disk(eb);
+
+               if (ret == 0 && check_tree_block(root, eb) == 0 &&
+                   csum_tree_block(root, eb, 1) == 0 &&
+                   verify_parent_transid(eb->tree, eb, parent_transid, ignore)
+                   == 0) {
+                       btrfs_set_buffer_uptodate(eb);
+                       return eb;
+               }
+               if (ignore) {
+                       if (check_tree_block(root, eb))
+                               printk("read block failed check_tree_block\n");
+                       else
+                               printk("Csum didn't match\n");
+                       break;
+               }
+               num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
+                                             eb->start, eb->len);
+               if (num_copies == 1) {
+                       ignore = 1;
+                       continue;
+               }
+               if (btrfs_header_generation(eb) > best_transid) {
+                       best_transid = btrfs_header_generation(eb);
+                       good_mirror = mirror_num;
+               }
+               mirror_num++;
+               if (mirror_num > num_copies) {
+                       mirror_num = good_mirror;
+                       ignore = 1;
+                       continue;
                }
-               btrfs_set_buffer_uptodate(eb);
        }
-       return eb;
+       free_extent_buffer(eb);
+       return NULL;
 }
 
 int write_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
                     struct extent_buffer *eb)
 {
+       int ret;
+       int dev_nr;
+       u64 length;
+       struct btrfs_multi_bio *multi = NULL;
+
        if (check_tree_block(root, eb))
                BUG();
-       if (!btrfs_buffer_uptodate(eb))
+       if (!btrfs_buffer_uptodate(eb, trans->transid))
                BUG();
-       btrfs_map_bh_to_logical(root, eb, eb->start);
+
+       btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
        csum_tree_block(root, eb, 0);
-       return write_extent_to_disk(eb);
+
+       dev_nr = 0;
+       length = eb->len;
+       ret = btrfs_map_block(&root->fs_info->mapping_tree, WRITE,
+                             eb->start, &length, &multi, 0);
+
+       while(dev_nr < multi->num_stripes) {
+               BUG_ON(ret);
+               eb->fd = multi->stripes[dev_nr].dev->fd;
+               eb->dev_bytenr = multi->stripes[dev_nr].physical;
+               multi->stripes[dev_nr].dev->total_ios++;
+               dev_nr++;
+               ret = write_extent_to_disk(eb);
+               BUG_ON(ret);
+       }
+       kfree(multi);
+       return 0;
 }
 
 static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
@@ -185,6 +327,8 @@ static int update_cowonly_root(struct btrfs_trans_handle *trans,
                        break;
                btrfs_set_root_bytenr(&root->root_item,
                                       root->node->start);
+               btrfs_set_root_generation(&root->root_item,
+                                         trans->transid);
                root->root_item.level = btrfs_header_level(root->node);
                ret = btrfs_update_root(trans, tree_root,
                                        &root->root_key,
@@ -200,6 +344,15 @@ static int commit_tree_roots(struct btrfs_trans_handle *trans,
 {
        struct btrfs_root *root;
        struct list_head *next;
+       struct extent_buffer *eb;
+
+       if (fs_info->readonly)
+               return 0;
+
+       eb = fs_info->tree_root->node;
+       extent_buffer_get(eb);
+       btrfs_cow_block(trans, fs_info->tree_root, eb, NULL, 0, &eb);
+       free_extent_buffer(eb);
 
        while(!list_empty(&fs_info->dirty_cowonly_roots)) {
                next = fs_info->dirty_cowonly_roots.next;
@@ -240,46 +393,21 @@ static int __commit_transaction(struct btrfs_trans_handle *trans,
 int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
                             struct btrfs_root *root)
 {
+       u64 transid = trans->transid;
        int ret = 0;
-       struct btrfs_root *new_root = NULL;
        struct btrfs_fs_info *fs_info = root->fs_info;
 
        if (root->commit_root == root->node)
                goto commit_tree;
 
-       new_root = malloc(sizeof(*new_root));
-       if (!new_root)
-               return -ENOMEM;
-       memcpy(new_root, root, sizeof(*new_root));
-       new_root->node = root->commit_root;
+       free_extent_buffer(root->commit_root);
        root->commit_root = NULL;
 
-       root->root_key.offset = trans->transid;
        btrfs_set_root_bytenr(&root->root_item, root->node->start);
+       btrfs_set_root_generation(&root->root_item, trans->transid);
        root->root_item.level = btrfs_header_level(root->node);
-       ret = btrfs_insert_root(trans, fs_info->tree_root,
-                               &root->root_key, &root->root_item);
-       BUG_ON(ret);
-
-       btrfs_set_root_refs(&new_root->root_item, 0);
        ret = btrfs_update_root(trans, root->fs_info->tree_root,
-                               &new_root->root_key, &new_root->root_item);
-       BUG_ON(ret);
-
-       ret = commit_tree_roots(trans, fs_info);
-       BUG_ON(ret);
-       ret = __commit_transaction(trans, root);
-       BUG_ON(ret);
-       write_ctree_super(trans, root);
-       btrfs_finish_extent_commit(trans, fs_info->extent_root,
-                                  &fs_info->pinned_extents);
-       btrfs_free_transaction(root, trans);
-       fs_info->running_transaction = NULL;
-
-       trans = btrfs_start_transaction(root, 1);
-       ret = btrfs_drop_snapshot(trans, new_root);
-       BUG_ON(ret);
-       ret = btrfs_del_root(trans, fs_info->tree_root, &new_root->root_key);
+                               &root->root_key, &root->root_item);
        BUG_ON(ret);
 commit_tree:
        ret = commit_tree_roots(trans, fs_info);
@@ -293,10 +421,7 @@ commit_tree:
        free_extent_buffer(root->commit_root);
        root->commit_root = NULL;
        fs_info->running_transaction = NULL;
-       if (new_root) {
-               free_extent_buffer(new_root->node);
-               free(new_root);
-       }
+       fs_info->last_trans_committed = transid;
        return 0;
 }
 
@@ -306,6 +431,7 @@ 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,
@@ -315,30 +441,76 @@ static int find_and_setup_root(struct btrfs_root *tree_root,
        BUG_ON(ret);
 
        blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
+       generation = btrfs_root_generation(&root->root_item);
        root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
-                                    blocksize);
+                                    blocksize, generation);
        BUG_ON(!root->node);
        return 0;
 }
 
-int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
+static int find_and_setup_log_root(struct btrfs_root *tree_root,
+                              struct btrfs_fs_info *fs_info,
+                              struct btrfs_super_block *disk_super)
+{
+       u32 blocksize;
+       u64 blocknr = btrfs_super_log_root(disk_super);
+       struct btrfs_root *log_root = malloc(sizeof(struct btrfs_root));
+
+       if (blocknr == 0)
+               return 0;
+
+       blocksize = btrfs_level_size(tree_root,
+                            btrfs_super_log_root_level(disk_super));
+
+       __setup_root(tree_root->nodesize, tree_root->leafsize,
+                    tree_root->sectorsize, tree_root->stripesize,
+                    log_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
+
+       log_root->node = read_tree_block(tree_root, blocknr,
+                                    blocksize,
+                                    btrfs_super_generation(disk_super) + 1);
+
+       fs_info->log_root_tree = log_root;
+       BUG_ON(!log_root->node);
+       return 0;
+}
+
+
+int btrfs_free_fs_root(struct btrfs_fs_info *fs_info,
+                      struct btrfs_root *root)
 {
        if (root->node)
                free_extent_buffer(root->node);
        if (root->commit_root)
                free_extent_buffer(root->commit_root);
+       kfree(root);
+       return 0;
+}
+
+static int free_fs_roots(struct btrfs_fs_info *fs_info)
+{
+       struct cache_extent *cache;
+       struct btrfs_root *root;
 
-       free(root);
+       while (1) {
+               cache = find_first_cache_extent(&fs_info->fs_root_cache, 0);
+               if (!cache)
+                       break;
+               root = container_of(cache, struct btrfs_root, cache);
+               remove_cache_extent(&fs_info->fs_root_cache, cache);
+               btrfs_free_fs_root(fs_info, root);
+       }
        return 0;
 }
 
-struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
-                                     struct btrfs_key *location)
+struct btrfs_root *btrfs_read_fs_root_no_cache(struct btrfs_fs_info *fs_info,
+                                              struct btrfs_key *location)
 {
        struct btrfs_root *root;
        struct btrfs_root *tree_root = fs_info->tree_root;
        struct btrfs_path *path;
        struct extent_buffer *l;
+       u64 generation;
        u32 blocksize;
        int ret = 0;
 
@@ -381,43 +553,75 @@ out:
                free(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);
+                                    blocksize, generation);
        BUG_ON(!root->node);
 insert:
        root->ref_cows = 1;
        return root;
 }
 
-struct btrfs_root *open_ctree(const char *filename, u64 sb_bytenr)
+struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
+                                     struct btrfs_key *location)
 {
-       int fp;
+       struct btrfs_root *root;
+       struct cache_extent *cache;
+       int ret;
 
-       fp = open(filename, O_CREAT | O_RDWR, 0600);
-       if (fp < 0) {
-               return NULL;
-       }
-       return open_ctree_fd(fp, filename, sb_bytenr);
+       if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
+               return fs_info->tree_root;
+       if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
+               return fs_info->extent_root;
+       if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
+               return fs_info->chunk_root;
+       if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
+               return fs_info->dev_root;
+       if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
+               return fs_info->csum_root;
+       
+       BUG_ON(location->objectid == BTRFS_TREE_RELOC_OBJECTID ||
+              location->offset != (u64)-1);
+
+       cache = find_cache_extent(&fs_info->fs_root_cache,
+                                 location->objectid, 1);
+       if (cache)
+               return container_of(cache, struct btrfs_root, cache);
+
+       root = btrfs_read_fs_root_no_cache(fs_info, location);
+       if (IS_ERR(root))
+               return root;
+
+       root->cache.start = location->objectid;
+       root->cache.size = 1;
+       ret = insert_existing_cache_extent(&fs_info->fs_root_cache,
+                                          &root->cache);
+       BUG_ON(ret);
+       return root;
 }
 
-struct btrfs_root *open_ctree_fd(int fp, const char *path, u64 sb_bytenr)
+struct btrfs_root *__open_ctree_fd(int fp, const char *path, u64 sb_bytenr,
+                                  u64 root_tree_bytenr, int writes)
 {
        u32 sectorsize;
        u32 nodesize;
        u32 leafsize;
        u32 blocksize;
        u32 stripesize;
-       struct btrfs_root *root = malloc(sizeof(struct btrfs_root));
+       u64 generation;
+       struct btrfs_key key;
        struct btrfs_root *tree_root = malloc(sizeof(struct btrfs_root));
        struct btrfs_root *extent_root = malloc(sizeof(struct btrfs_root));
        struct btrfs_root *chunk_root = malloc(sizeof(struct btrfs_root));
        struct btrfs_root *dev_root = malloc(sizeof(struct btrfs_root));
+       struct btrfs_root *csum_root = malloc(sizeof(struct btrfs_root));
        struct btrfs_fs_info *fs_info = malloc(sizeof(*fs_info));
        int ret;
        struct btrfs_super_block *disk_super;
        struct btrfs_fs_devices *fs_devices = NULL;
        u64 total_devs;
+       u64 features;
 
        if (sb_bytenr == 0)
                sb_bytenr = BTRFS_SUPER_INFO_OFFSET;
@@ -427,26 +631,24 @@ struct btrfs_root *open_ctree_fd(int fp, const char *path, u64 sb_bytenr)
 
        if (ret) {
                fprintf(stderr, "No valid Btrfs found on %s\n", path);
-               return NULL;
+               goto out;
        }
-       fprintf(stderr, "found Btrfs on %s with %Lu devices\n", path,
-               total_devs);
 
        if (total_devs != 1) {
                ret = btrfs_scan_for_fsid(fs_devices, total_devs, 1);
-               BUG_ON(ret);
+               if (ret)
+                       goto out;
        }
 
-       fs_info->fp = fs_devices->lowest_bdev;
-       fs_info->running_transaction = NULL;
-       fs_info->fs_root = root;
+       memset(fs_info, 0, sizeof(*fs_info));
        fs_info->tree_root = tree_root;
        fs_info->extent_root = extent_root;
-       fs_info->extent_ops = NULL;
-       fs_info->priv_data = NULL;
        fs_info->chunk_root = chunk_root;
        fs_info->dev_root = dev_root;
-       fs_info->force_system_allocs = 0;
+       fs_info->csum_root = csum_root;
+
+       if (!writes)
+               fs_info->readonly = 1;
 
        extent_io_tree_init(&fs_info->extent_cache);
        extent_io_tree_init(&fs_info->free_space_cache);
@@ -454,6 +656,7 @@ struct btrfs_root *open_ctree_fd(int fp, const char *path, u64 sb_bytenr)
        extent_io_tree_init(&fs_info->pinned_extents);
        extent_io_tree_init(&fs_info->pending_del);
        extent_io_tree_init(&fs_info->extent_ins);
+       cache_tree_init(&fs_info->fs_root_cache);
 
        cache_tree_init(&fs_info->mapping_tree.cache_tree);
 
@@ -465,30 +668,49 @@ struct btrfs_root *open_ctree_fd(int fp, const char *path, u64 sb_bytenr)
        __setup_root(4096, 4096, 4096, 4096, tree_root,
                     fs_info, BTRFS_ROOT_TREE_OBJECTID);
 
-       ret = btrfs_open_devices(fs_devices, O_RDWR);
-       BUG_ON(ret);
-
-       fs_info->sb_buffer = btrfs_find_create_tree_block(tree_root, sb_bytenr,
-                                                         4096);
-       BUG_ON(!fs_info->sb_buffer);
-       fs_info->sb_buffer->fd = fs_devices->lowest_bdev;
-       fs_info->sb_buffer->dev_bytenr = sb_bytenr;
-       ret = read_extent_from_disk(fs_info->sb_buffer);
-       BUG_ON(ret);
-       btrfs_set_buffer_uptodate(fs_info->sb_buffer);
-
-       read_extent_buffer(fs_info->sb_buffer, &fs_info->super_copy, 0,
-                          sizeof(fs_info->super_copy));
-       read_extent_buffer(fs_info->sb_buffer, fs_info->fsid,
-                          (unsigned long)btrfs_super_fsid(fs_info->sb_buffer),
-                          BTRFS_FSID_SIZE);
+       if (writes)
+               ret = btrfs_open_devices(fs_devices, O_RDWR);
+       else
+               ret = btrfs_open_devices(fs_devices, O_RDONLY);
+       if (ret)
+               goto out_cleanup;
 
+       fs_info->super_bytenr = sb_bytenr;
        disk_super = &fs_info->super_copy;
-       if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
-                   sizeof(disk_super->magic))) {
+       ret = btrfs_read_dev_super(fs_devices->latest_bdev,
+                                  disk_super, sb_bytenr);
+       if (ret) {
                printk("No valid btrfs found\n");
-               BUG_ON(1);
+               goto out_devices;
+       }
+
+       memcpy(fs_info->fsid, &disk_super->fsid, BTRFS_FSID_SIZE);
+
+
+       features = btrfs_super_incompat_flags(disk_super) &
+                  ~BTRFS_FEATURE_INCOMPAT_SUPP;
+       if (features) {
+               printk("couldn't open because of unsupported "
+                      "option features (%Lx).\n",
+                      (unsigned long long)features);
+               goto out_devices;
+       }
+
+       features = btrfs_super_incompat_flags(disk_super);
+       if (!(features & BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF)) {
+               features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
+               btrfs_set_super_incompat_flags(disk_super, features);
+       }
+
+       features = btrfs_super_compat_ro_flags(disk_super) &
+               ~BTRFS_FEATURE_COMPAT_RO_SUPP;
+       if (writes && features) {
+               printk("couldn't open RDWR because of unsupported "
+                      "option features (%Lx).\n",
+                      (unsigned long long)features);
+               goto out_devices;
        }
+
        nodesize = btrfs_super_nodesize(disk_super);
        leafsize = btrfs_super_leafsize(disk_super);
        sectorsize = btrfs_super_sectorsize(disk_super);
@@ -498,57 +720,295 @@ struct btrfs_root *open_ctree_fd(int fp, const char *path, u64 sb_bytenr)
        tree_root->sectorsize = sectorsize;
        tree_root->stripesize = stripesize;
 
-       ret = btrfs_read_super_device(tree_root, fs_info->sb_buffer);
-       BUG_ON(ret);
        ret = btrfs_read_sys_array(tree_root);
-       BUG_ON(ret);
+       if (ret)
+               goto out_devices;
        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);
+                                          blocksize, generation);
+       if (!chunk_root->node) {
+               printk("Couldn't read chunk root\n");
+               goto out_devices;
+       }
 
-       BUG_ON(!chunk_root->node);
+       read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
+                (unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node),
+                BTRFS_UUID_SIZE);
 
-       ret = btrfs_read_chunk_tree(chunk_root);
-       BUG_ON(ret);
+       if (!(btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_METADUMP)) {
+               ret = btrfs_read_chunk_tree(chunk_root);
+               if (ret)
+                       goto out_chunk;
+       }
 
        blocksize = btrfs_level_size(tree_root,
                                     btrfs_super_root_level(disk_super));
+       generation = btrfs_super_generation(disk_super);
 
+       if (!root_tree_bytenr)
+               root_tree_bytenr = btrfs_super_root(disk_super);
        tree_root->node = read_tree_block(tree_root,
-                                         btrfs_super_root(disk_super),
-                                         blocksize);
-       BUG_ON(!tree_root->node);
+                                         root_tree_bytenr,
+                                         blocksize, generation);
+       if (!tree_root->node) {
+               printk("Couldn't read tree root\n");
+               goto out_chunk;
+       }
        ret = find_and_setup_root(tree_root, fs_info,
                                  BTRFS_EXTENT_TREE_OBJECTID, extent_root);
-       BUG_ON(ret);
+       if (ret) {
+               printk("Couldn't setup extent tree\n");
+               goto out_tree;
+       }
        extent_root->track_dirty = 1;
 
        ret = find_and_setup_root(tree_root, fs_info,
                                  BTRFS_DEV_TREE_OBJECTID, dev_root);
-       BUG_ON(ret);
+       if (ret) {
+               printk("Couldn't setup device tree\n");
+               goto out_extent;
+       }
        dev_root->track_dirty = 1;
 
        ret = find_and_setup_root(tree_root, fs_info,
-                                 BTRFS_FS_TREE_OBJECTID, root);
-       BUG_ON(ret);
-       root->ref_cows = 1;
-       fs_info->generation = btrfs_super_generation(disk_super) + 1;
-       btrfs_read_block_groups(root);
+                                 BTRFS_CSUM_TREE_OBJECTID, csum_root);
+       if (ret) {
+               printk("Couldn't setup csum tree\n");
+               goto out_dev;
+       }
+       csum_root->track_dirty = 1;
+
+       find_and_setup_log_root(tree_root, fs_info, disk_super);
+
+       fs_info->generation = generation;
+       fs_info->last_trans_committed = generation;
+       btrfs_read_block_groups(fs_info->tree_root);
+
+       key.objectid = BTRFS_FS_TREE_OBJECTID;
+       key.type = BTRFS_ROOT_ITEM_KEY;
+       key.offset = (u64)-1;
+       fs_info->fs_root = btrfs_read_fs_root(fs_info, &key);
+
+       if (!fs_info->fs_root)
+               goto out_csum;
+
+       fs_info->data_alloc_profile = (u64)-1;
+       fs_info->metadata_alloc_profile = (u64)-1;
+       fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
+
+       return fs_info->fs_root;
+out_csum:
+       free_extent_buffer(fs_info->csum_root->node);
+out_dev:
+       free_extent_buffer(fs_info->dev_root->node);
+out_extent:
+       free_extent_buffer(fs_info->extent_root->node);
+out_tree:
+       free_extent_buffer(fs_info->tree_root->node);
+out_chunk:
+       free_extent_buffer(fs_info->chunk_root->node);
+out_devices:
+       close_all_devices(fs_info);
+out_cleanup:
+       extent_io_tree_cleanup(&fs_info->extent_cache);
+       extent_io_tree_cleanup(&fs_info->free_space_cache);
+       extent_io_tree_cleanup(&fs_info->block_group_cache);
+       extent_io_tree_cleanup(&fs_info->pinned_extents);
+       extent_io_tree_cleanup(&fs_info->pending_del);
+       extent_io_tree_cleanup(&fs_info->extent_ins);
+out:
+       free(tree_root);
+       free(extent_root);
+       free(chunk_root);
+       free(dev_root);
+       free(csum_root);
+       free(fs_info);
+       return NULL;
+}
+
+struct btrfs_root *open_ctree(const char *filename, u64 sb_bytenr, int writes)
+{
+       int fp;
+       struct btrfs_root *root;
+       int flags = O_CREAT | O_RDWR;
+
+       if (!writes)
+               flags = O_RDONLY;
+
+       fp = open(filename, flags, 0600);
+       if (fp < 0) {
+               fprintf (stderr, "Could not open %s\n", filename);
+               return NULL;
+       }
+       root = __open_ctree_fd(fp, filename, sb_bytenr, 0, writes);
+       close(fp);
+
        return root;
 }
 
+struct btrfs_root *open_ctree_recovery(const char *filename, u64 sb_bytenr,
+                                      u64 root_tree_bytenr)
+{
+       int fp;
+       struct btrfs_root *root;
+
+       fp = open(filename, O_RDONLY);
+       if (fp < 0) {
+               fprintf (stderr, "Could not open %s\n", filename);
+               return NULL;
+       }
+       root = __open_ctree_fd(fp, filename, sb_bytenr, root_tree_bytenr, 0);
+       close(fp);
+
+       return root;
+}
+
+struct btrfs_root *open_ctree_fd(int fp, const char *path, u64 sb_bytenr,
+                                int writes)
+{
+       return __open_ctree_fd(fp, path, sb_bytenr, 0, writes);
+}
+
+int btrfs_read_dev_super(int fd, struct btrfs_super_block *sb, u64 sb_bytenr)
+{
+       u8 fsid[BTRFS_FSID_SIZE];
+       struct btrfs_super_block buf;
+       int i;
+       int ret;
+       u64 transid = 0;
+       u64 bytenr;
+
+       if (sb_bytenr != BTRFS_SUPER_INFO_OFFSET) {
+               ret = pread64(fd, &buf, sizeof(buf), sb_bytenr);
+               if (ret < sizeof(buf))
+                       return -1;
+
+               if (btrfs_super_bytenr(&buf) != sb_bytenr ||
+                   strncmp((char *)(&buf.magic), BTRFS_MAGIC,
+                           sizeof(buf.magic)))
+                       return -1;
+
+               memcpy(sb, &buf, sizeof(*sb));
+               return 0;
+       }
+
+       for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
+               bytenr = btrfs_sb_offset(i);
+               ret = pread64(fd, &buf, sizeof(buf), bytenr);
+               if (ret < sizeof(buf))
+                       break;
+
+               if (btrfs_super_bytenr(&buf) != bytenr ||
+                   strncmp((char *)(&buf.magic), BTRFS_MAGIC,
+                           sizeof(buf.magic)))
+                       continue;
+
+               if (i == 0)
+                       memcpy(fsid, buf.fsid, sizeof(fsid));
+               else if (memcmp(fsid, buf.fsid, sizeof(fsid)))
+                       continue;
+
+               if (btrfs_super_generation(&buf) > transid) {
+                       memcpy(sb, &buf, sizeof(*sb));
+                       transid = btrfs_super_generation(&buf);
+               }
+       }
+
+       return transid > 0 ? 0 : -1;
+}
+
+int write_dev_supers(struct btrfs_root *root, struct btrfs_super_block *sb,
+                    struct btrfs_device *device)
+{
+       u64 bytenr;
+       u32 crc;
+       int i, ret;
+
+       if (root->fs_info->super_bytenr != BTRFS_SUPER_INFO_OFFSET) {
+               btrfs_set_super_bytenr(sb, root->fs_info->super_bytenr);
+               crc = ~(u32)0;
+               crc = btrfs_csum_data(NULL, (char *)sb + BTRFS_CSUM_SIZE, crc,
+                                     BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
+               btrfs_csum_final(crc, (char *)&sb->csum[0]);
+
+               ret = pwrite64(device->fd, sb, BTRFS_SUPER_INFO_SIZE,
+                              root->fs_info->super_bytenr);
+               BUG_ON(ret != BTRFS_SUPER_INFO_SIZE);
+               return 0;
+       }
+
+       for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
+               bytenr = btrfs_sb_offset(i);
+               if (bytenr + BTRFS_SUPER_INFO_SIZE >= device->total_bytes)
+                       break;
+
+               btrfs_set_super_bytenr(sb, bytenr);
+
+               crc = ~(u32)0;
+               crc = btrfs_csum_data(NULL, (char *)sb + BTRFS_CSUM_SIZE, crc,
+                                     BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
+               btrfs_csum_final(crc, (char *)&sb->csum[0]);
+
+               ret = pwrite64(device->fd, sb, BTRFS_SUPER_INFO_SIZE, bytenr);
+               BUG_ON(ret != BTRFS_SUPER_INFO_SIZE);
+       }
+       return 0;
+}
+
+int write_all_supers(struct btrfs_root *root)
+{
+       struct list_head *cur;
+       struct list_head *head = &root->fs_info->fs_devices->devices;
+       struct btrfs_device *dev;
+       struct btrfs_super_block *sb;
+       struct btrfs_dev_item *dev_item;
+       int ret;
+       u64 flags;
+
+       sb = &root->fs_info->super_copy;
+       dev_item = &sb->dev_item;
+       list_for_each(cur, head) {
+               dev = list_entry(cur, struct btrfs_device, dev_list);
+               if (!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);
+               btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used);
+               btrfs_set_stack_device_io_align(dev_item, dev->io_align);
+               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);
+
+               ret = write_dev_supers(root, sb, dev);
+               BUG_ON(ret);
+       }
+       return 0;
+}
+
 int write_ctree_super(struct btrfs_trans_handle *trans,
                      struct btrfs_root *root)
 {
        int ret;
        struct btrfs_root *tree_root = root->fs_info->tree_root;
        struct btrfs_root *chunk_root = root->fs_info->chunk_root;
+
+       if (root->fs_info->readonly)
+               return 0;
+
        btrfs_set_super_generation(&root->fs_info->super_copy,
                                   trans->transid);
        btrfs_set_super_root(&root->fs_info->super_copy,
@@ -559,10 +1019,10 @@ int write_ctree_super(struct btrfs_trans_handle *trans,
                                   chunk_root->node->start);
        btrfs_set_super_chunk_root_level(&root->fs_info->super_copy,
                                         btrfs_header_level(chunk_root->node));
-       write_extent_buffer(root->fs_info->sb_buffer,
-                           &root->fs_info->super_copy, 0,
-                           sizeof(root->fs_info->super_copy));
-       ret = write_tree_block(trans, root, root->fs_info->sb_buffer);
+       btrfs_set_super_chunk_root_generation(&root->fs_info->super_copy,
+                               btrfs_header_generation(chunk_root->node));
+
+       ret = write_all_supers(root);
        if (ret)
                fprintf(stderr, "failed to write new super block err %d\n", ret);
        return ret;
@@ -579,7 +1039,7 @@ static int close_all_devices(struct btrfs_fs_info *fs_info)
        list = &fs_info->fs_devices->devices;
        list_for_each(next, list) {
                device = list_entry(next, struct btrfs_device, dev_list);
-               // close(device->fd);
+               close(device->fd);
        }
        return 0;
 }
@@ -590,33 +1050,40 @@ int close_ctree(struct btrfs_root *root)
        struct btrfs_trans_handle *trans;
        struct btrfs_fs_info *fs_info = root->fs_info;
 
-       trans = btrfs_start_transaction(root, 1);
-       btrfs_commit_transaction(trans, root);
-       trans = btrfs_start_transaction(root, 1);
-       ret = commit_tree_roots(trans, root->fs_info);
-       BUG_ON(ret);
-       ret = __commit_transaction(trans, root);
-       BUG_ON(ret);
-       write_ctree_super(trans, root);
-       btrfs_free_transaction(root, trans);
-       btrfs_free_block_groups(root->fs_info);
-       close(root->fs_info->fp);
-       if (root->node)
-               free_extent_buffer(root->node);
-       if (root->fs_info->extent_root->node)
-               free_extent_buffer(root->fs_info->extent_root->node);
-       if (root->fs_info->tree_root->node)
-               free_extent_buffer(root->fs_info->tree_root->node);
-       free_extent_buffer(root->commit_root);
-       free_extent_buffer(root->fs_info->sb_buffer);
-
-       if (root->fs_info->chunk_root->node);
-               free_extent_buffer(root->fs_info->chunk_root->node);
-
-       if (root->fs_info->dev_root->node);
-               free_extent_buffer(root->fs_info->dev_root->node);
+       if (fs_info->last_trans_committed !=
+           fs_info->generation) {
+               trans = btrfs_start_transaction(root, 1);
+               btrfs_commit_transaction(trans, root);
+               trans = btrfs_start_transaction(root, 1);
+               ret = commit_tree_roots(trans, fs_info);
+               BUG_ON(ret);
+               ret = __commit_transaction(trans, root);
+               BUG_ON(ret);
+               write_ctree_super(trans, root);
+               btrfs_free_transaction(root, trans);
+       }
+       btrfs_free_block_groups(fs_info);
+
+       free_fs_roots(fs_info);
+
+       if (fs_info->extent_root->node)
+               free_extent_buffer(fs_info->extent_root->node);
+       if (fs_info->tree_root->node)
+               free_extent_buffer(fs_info->tree_root->node);
+       if (fs_info->chunk_root->node)
+               free_extent_buffer(fs_info->chunk_root->node);
+       if (fs_info->dev_root->node)
+               free_extent_buffer(fs_info->dev_root->node);
+       if (fs_info->csum_root->node)
+               free_extent_buffer(fs_info->csum_root->node);
+
+       if (fs_info->log_root_tree) {
+               if (fs_info->log_root_tree->node)
+                       free_extent_buffer(fs_info->log_root_tree->node);
+               free(fs_info->log_root_tree);
+       }
 
-       close_all_devices(root->fs_info);
+       close_all_devices(fs_info);
        extent_io_tree_cleanup(&fs_info->extent_cache);
        extent_io_tree_cleanup(&fs_info->free_space_cache);
        extent_io_tree_cleanup(&fs_info->block_group_cache);
@@ -626,9 +1093,9 @@ int close_ctree(struct btrfs_root *root)
 
        free(fs_info->tree_root);
        free(fs_info->extent_root);
-       free(fs_info->fs_root);
        free(fs_info->chunk_root);
        free(fs_info->dev_root);
+       free(fs_info->csum_root);
        free(fs_info);
 
        return 0;
@@ -651,9 +1118,16 @@ void btrfs_mark_buffer_dirty(struct extent_buffer *eb)
        set_extent_buffer_dirty(eb);
 }
 
-int btrfs_buffer_uptodate(struct extent_buffer *eb)
+int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid)
 {
-       return extent_buffer_uptodate(eb);
+       int ret;
+
+       ret = extent_buffer_uptodate(buf);
+       if (!ret)
+               return ret;
+
+       ret = verify_parent_transid(buf->tree, buf, parent_transid, 1);
+       return !ret;
 }
 
 int btrfs_set_buffer_uptodate(struct extent_buffer *eb)