btrfs-progs: docs: fix typos
[platform/upstream/btrfs-progs.git] / disk-io.c
index a11e626..58eae70 100644 (file)
--- a/disk-io.c
+++ b/disk-io.c
@@ -182,27 +182,28 @@ struct extent_buffer *btrfs_find_tree_block(struct btrfs_fs_info *fs_info,
 }
 
 struct extent_buffer* btrfs_find_create_tree_block(
-               struct btrfs_fs_info *fs_info, u64 bytenr, u32 blocksize)
+               struct btrfs_fs_info *fs_info, u64 bytenr)
 {
-       return alloc_extent_buffer(&fs_info->extent_cache, bytenr, blocksize);
+       return alloc_extent_buffer(&fs_info->extent_cache, bytenr,
+                       fs_info->nodesize);
 }
 
 void readahead_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr,
-                         u32 blocksize, u64 parent_transid)
+               u64 parent_transid)
 {
        struct extent_buffer *eb;
        u64 length;
        struct btrfs_multi_bio *multi = NULL;
        struct btrfs_device *device;
 
-       eb = btrfs_find_tree_block(fs_info, bytenr, blocksize);
+       eb = btrfs_find_tree_block(fs_info, bytenr, fs_info->nodesize);
        if (!(eb && btrfs_buffer_uptodate(eb, parent_transid)) &&
            !btrfs_map_block(fs_info, READ, bytenr, &length, &multi, 0,
                             NULL)) {
                device = multi->stripes[0].dev;
                device->total_ios++;
-               blocksize = min(blocksize, (u32)SZ_64K);
-               readahead(device->fd, multi->stripes[0].physical, blocksize);
+               readahead(device->fd, multi->stripes[0].physical,
+                               fs_info->nodesize);
        }
 
        free_extent_buffer(eb);
@@ -299,15 +300,13 @@ int read_whole_eb(struct btrfs_fs_info *info, struct extent_buffer *eb, int mirr
        return 0;
 }
 
-struct extent_buffer* read_tree_block(
-               struct btrfs_fs_info *fs_info, u64 bytenr, u32 blocksize,
+struct extent_buffer* read_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr,
                u64 parent_transid)
 {
        int ret;
        struct extent_buffer *eb;
        u64 best_transid = 0;
        u32 sectorsize = fs_info->sectorsize;
-       u32 nodesize = fs_info->nodesize;
        int mirror_num = 0;
        int good_mirror = 0;
        int num_copies;
@@ -324,13 +323,8 @@ struct extent_buffer* read_tree_block(
                      bytenr, sectorsize);
                return ERR_PTR(-EIO);
        }
-       if (blocksize < nodesize || !IS_ALIGNED(blocksize, nodesize)) {
-               error("tree block size %u is not aligned to nodesize %u",
-                     blocksize, nodesize);
-               return ERR_PTR(-EIO);
-       }
 
-       eb = btrfs_find_create_tree_block(fs_info, bytenr, blocksize);
+       eb = btrfs_find_create_tree_block(fs_info, bytenr);
        if (!eb)
                return ERR_PTR(-ENOMEM);
 
@@ -402,10 +396,12 @@ int read_extent_data(struct btrfs_fs_info *fs_info, char *data, u64 logical,
        }
        device = multi->stripes[0].dev;
 
-       if (device->fd <= 0)
-               goto err;
        if (*len > max_len)
                *len = max_len;
+       if (device->fd < 0) {
+               ret = -EIO;
+               goto err;
+       }
 
        ret = pread64(device->fd, data, *len, multi->stripes[0].physical);
        if (ret != *len)
@@ -487,135 +483,11 @@ void btrfs_setup_root(struct btrfs_root *root, struct btrfs_fs_info *fs_info,
        root->root_key.objectid = objectid;
 }
 
-static int update_cowonly_root(struct btrfs_trans_handle *trans,
-                              struct btrfs_root *root)
-{
-       int ret;
-       u64 old_root_bytenr;
-       struct btrfs_root *tree_root = root->fs_info->tree_root;
-
-       btrfs_write_dirty_block_groups(trans, root);
-       while(1) {
-               old_root_bytenr = btrfs_root_bytenr(&root->root_item);
-               if (old_root_bytenr == root->node->start)
-                       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,
-                                       &root->root_item);
-               BUG_ON(ret);
-               btrfs_write_dirty_block_groups(trans, root);
-       }
-       return 0;
-}
-
-static int commit_tree_roots(struct btrfs_trans_handle *trans,
-                            struct btrfs_fs_info *fs_info)
-{
-       struct btrfs_root *root;
-       struct list_head *next;
-       struct extent_buffer *eb;
-       int ret;
-
-       if (fs_info->readonly)
-               return 0;
-
-       eb = fs_info->tree_root->node;
-       extent_buffer_get(eb);
-       ret = btrfs_cow_block(trans, fs_info->tree_root, eb, NULL, 0, &eb);
-       free_extent_buffer(eb);
-       if (ret)
-               return ret;
-
-       while(!list_empty(&fs_info->dirty_cowonly_roots)) {
-               next = fs_info->dirty_cowonly_roots.next;
-               list_del_init(next);
-               root = list_entry(next, struct btrfs_root, dirty_list);
-               update_cowonly_root(trans, root);
-               free_extent_buffer(root->commit_root);
-               root->commit_root = NULL;
-       }
-
-       return 0;
-}
-
-static int __commit_transaction(struct btrfs_trans_handle *trans,
-                               struct btrfs_root *root)
-{
-       u64 start;
-       u64 end;
-       struct btrfs_fs_info *fs_info = root->fs_info;
-       struct extent_buffer *eb;
-       struct extent_io_tree *tree = &fs_info->extent_cache;
-       int ret;
-
-       while(1) {
-               ret = find_first_extent_bit(tree, 0, &start, &end,
-                                           EXTENT_DIRTY);
-               if (ret)
-                       break;
-               while(start <= end) {
-                       eb = find_first_extent_buffer(tree, start);
-                       BUG_ON(!eb || eb->start != start);
-                       ret = write_tree_block(trans, fs_info, eb);
-                       BUG_ON(ret);
-                       start += eb->len;
-                       clear_extent_buffer_dirty(eb);
-                       free_extent_buffer(eb);
-               }
-       }
-       return 0;
-}
-
-int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
-                            struct btrfs_root *root)
-{
-       u64 transid = trans->transid;
-       int ret = 0;
-       struct btrfs_fs_info *fs_info = root->fs_info;
-
-       if (root->commit_root == root->node)
-               goto commit_tree;
-       if (root == root->fs_info->tree_root)
-               goto commit_tree;
-       if (root == root->fs_info->chunk_root)
-               goto commit_tree;
-
-       free_extent_buffer(root->commit_root);
-       root->commit_root = NULL;
-
-       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, root->fs_info->tree_root,
-                               &root->root_key, &root->root_item);
-       BUG_ON(ret);
-commit_tree:
-       ret = commit_tree_roots(trans, fs_info);
-       BUG_ON(ret);
-       ret = __commit_transaction(trans, root);
-       BUG_ON(ret);
-       write_ctree_super(trans, fs_info);
-       btrfs_finish_extent_commit(trans, fs_info->extent_root,
-                                  &fs_info->pinned_extents);
-       kfree(trans);
-       free_extent_buffer(root->commit_root);
-       root->commit_root = NULL;
-       fs_info->running_transaction = NULL;
-       fs_info->last_trans_committed = transid;
-       return 0;
-}
-
 static int find_and_setup_root(struct btrfs_root *tree_root,
                               struct btrfs_fs_info *fs_info,
                               u64 objectid, struct btrfs_root *root)
 {
        int ret;
-       u32 blocksize;
        u64 generation;
 
        btrfs_setup_root(root, fs_info, objectid);
@@ -624,11 +496,9 @@ static int find_and_setup_root(struct btrfs_root *tree_root,
        if (ret)
                return ret;
 
-       blocksize = fs_info->nodesize;
        generation = btrfs_root_generation(&root->root_item);
        root->node = read_tree_block(fs_info,
-                       btrfs_root_bytenr(&root->root_item),
-                       blocksize, generation);
+                       btrfs_root_bytenr(&root->root_item), generation);
        if (!extent_buffer_uptodate(root->node))
                return -EIO;
 
@@ -639,7 +509,6 @@ 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));
 
@@ -651,13 +520,10 @@ static int find_and_setup_log_root(struct btrfs_root *tree_root,
                return 0;
        }
 
-       blocksize = fs_info->nodesize;
-
        btrfs_setup_root(log_root, fs_info,
                         BTRFS_TREE_LOG_OBJECTID);
 
        log_root->node = read_tree_block(fs_info, blocknr,
-                                    blocksize,
                                     btrfs_super_generation(disk_super) + 1);
 
        fs_info->log_root_tree = log_root;
@@ -700,7 +566,6 @@ struct btrfs_root *btrfs_read_fs_root_no_cache(struct btrfs_fs_info *fs_info,
        struct btrfs_path *path;
        struct extent_buffer *l;
        u64 generation;
-       u32 blocksize;
        int ret = 0;
 
        root = calloc(1, sizeof(*root));
@@ -744,10 +609,8 @@ out:
                return ERR_PTR(ret);
        }
        generation = btrfs_root_generation(&root->root_item);
-       blocksize = fs_info->nodesize;
        root->node = read_tree_block(fs_info,
-                       btrfs_root_bytenr(&root->root_item),
-                       blocksize, generation);
+                       btrfs_root_bytenr(&root->root_item), generation);
        if (!extent_buffer_uptodate(root->node)) {
                free(root);
                return ERR_PTR(-EIO);
@@ -953,9 +816,7 @@ static int setup_root_or_create_block(struct btrfs_fs_info *fs_info,
                                      struct btrfs_root *info_root,
                                      u64 objectid, char *str)
 {
-       struct btrfs_super_block *sb = fs_info->super_copy;
        struct btrfs_root *root = fs_info->tree_root;
-       u32 nodesize = btrfs_super_nodesize(sb);
        int ret;
 
        ret = find_and_setup_root(root, fs_info, objectid, info_root);
@@ -968,7 +829,7 @@ static int setup_root_or_create_block(struct btrfs_fs_info *fs_info,
                 * million of places that assume a root has a valid ->node
                 */
                info_root->node =
-                       btrfs_find_create_tree_block(fs_info, 0, nodesize);
+                       btrfs_find_create_tree_block(fs_info, 0);
                if (!info_root->node)
                        return -ENOMEM;
                clear_extent_buffer_uptodate(info_root->node);
@@ -984,12 +845,10 @@ int btrfs_setup_all_roots(struct btrfs_fs_info *fs_info, u64 root_tree_bytenr,
        struct btrfs_root *root;
        struct btrfs_key key;
        u64 generation;
-       u32 blocksize;
        int ret;
 
        root = fs_info->tree_root;
        btrfs_setup_root(root, fs_info, BTRFS_ROOT_TREE_OBJECTID);
-       blocksize = fs_info->nodesize;
        generation = btrfs_super_generation(sb);
 
        if (!root_tree_bytenr && !(flags & OPEN_CTREE_BACKUP_ROOT)) {
@@ -1006,8 +865,7 @@ int btrfs_setup_all_roots(struct btrfs_fs_info *fs_info, u64 root_tree_bytenr,
                generation = btrfs_backup_tree_root_gen(backup);
        }
 
-       root->node = read_tree_block(fs_info, root_tree_bytenr, blocksize,
-                                    generation);
+       root->node = read_tree_block(fs_info, root_tree_bytenr, generation);
        if (!extent_buffer_uptodate(root->node)) {
                fprintf(stderr, "Couldn't read tree root\n");
                return -EIO;
@@ -1062,8 +920,16 @@ int btrfs_setup_all_roots(struct btrfs_fs_info *fs_info, u64 root_tree_bytenr,
        fs_info->generation = generation;
        fs_info->last_trans_committed = generation;
        if (extent_buffer_uptodate(fs_info->extent_root->node) &&
-           !(flags & OPEN_CTREE_NO_BLOCK_GROUPS))
-               btrfs_read_block_groups(fs_info->tree_root);
+           !(flags & OPEN_CTREE_NO_BLOCK_GROUPS)) {
+               ret = btrfs_read_block_groups(fs_info->tree_root);
+               /*
+                * If we don't find any blockgroups (ENOENT) we're either
+                * restoring or creating the filesystem, where it's expected,
+                * anything else is error
+                */
+               if (ret != -ENOENT)
+                       return -EIO;
+       }
 
        key.objectid = BTRFS_FS_TREE_OBJECTID;
        key.type = BTRFS_ROOT_ITEM_KEY;
@@ -1173,7 +1039,7 @@ int btrfs_setup_chunk_tree_and_device_map(struct btrfs_fs_info *fs_info,
        btrfs_setup_root(fs_info->chunk_root, fs_info,
                        BTRFS_CHUNK_TREE_OBJECTID);
 
-       ret = btrfs_read_sys_array(fs_info->chunk_root);
+       ret = btrfs_read_sys_array(fs_info);
        if (ret)
                return ret;
 
@@ -1193,7 +1059,6 @@ int btrfs_setup_chunk_tree_and_device_map(struct btrfs_fs_info *fs_info,
 
        fs_info->chunk_root->node = read_tree_block(fs_info,
                                                    chunk_root_bytenr,
-                                                   fs_info->nodesize,
                                                    generation);
        if (!extent_buffer_uptodate(fs_info->chunk_root->node)) {
                if (fs_info->ignore_chunk_tree_error) {
@@ -1207,7 +1072,7 @@ int btrfs_setup_chunk_tree_and_device_map(struct btrfs_fs_info *fs_info,
        }
 
        if (!(btrfs_super_flags(sb) & BTRFS_SUPER_FLAG_METADUMP)) {
-               ret = btrfs_read_chunk_tree(fs_info->chunk_root);
+               ret = btrfs_read_chunk_tree(fs_info);
                if (ret) {
                        fprintf(stderr, "Couldn't read chunk tree\n");
                        return ret;
@@ -1349,7 +1214,7 @@ struct btrfs_fs_info *open_ctree_fs_info(const char *filename,
 
        ret = stat(filename, &st);
        if (ret < 0) {
-               error("cannot stat '%s': %s", filename, strerror(errno));
+               error("cannot stat '%s': %m", filename);
                return NULL;
        }
        if (!(((st.st_mode & S_IFMT) == S_IFREG) || ((st.st_mode & S_IFMT) == S_IFBLK))) {
@@ -1362,7 +1227,7 @@ struct btrfs_fs_info *open_ctree_fs_info(const char *filename,
 
        fp = open(filename, oflags);
        if (fp < 0) {
-               error("cannot open '%s': %s", filename, strerror(errno));
+               error("cannot open '%s': %m", filename);
                return NULL;
        }
        info = __open_ctree_fd(fp, filename, sb_bytenr, root_tree_bytenr,
@@ -1556,6 +1421,23 @@ error_out:
        return -EIO;
 }
 
+/*
+ * btrfs_read_dev_super - read a valid superblock from a block device
+ * @fd:                file descriptor of the device
+ * @sb:                buffer where the superblock is going to be read in
+ * @sb_bytenr:  offset of the particular superblock copy we want
+ * @sbflags:   flags controlling how the superblock is read
+ *
+ * This function is used by various btrfs comands to obtain a valid superblock.
+ *
+ * It's mode of operation is controlled by the @sb_bytenr and @sbdflags
+ * parameters. If SBREAD_RECOVER flag is set and @sb_bytenr is
+ * BTRFS_SUPER_INFO_OFFSET then the function reads all 3 superblock copies and
+ * returns the newest one. If SBREAD_RECOVER is not set then only a single
+ * copy is read, which one is decided by @sb_bytenr. If @sb_bytenr !=
+ * BTRFS_SUPER_INFO_OFFSET then the @sbflags is effectively ignored and only a
+ * single copy is read.
+ */
 int btrfs_read_dev_super(int fd, struct btrfs_super_block *sb, u64 sb_bytenr,
                         unsigned sbflags)
 {
@@ -1686,14 +1568,12 @@ write_err:
        if (ret > 0)
                fprintf(stderr, "WARNING: failed to write all sb data\n");
        else
-               fprintf(stderr, "WARNING: failed to write sb: %s\n",
-                       strerror(errno));
+               fprintf(stderr, "WARNING: failed to write sb: %m\n");
        return ret;
 }
 
 int write_all_supers(struct btrfs_fs_info *fs_info)
 {
-       struct list_head *cur;
        struct list_head *head = &fs_info->fs_devices->devices;
        struct btrfs_device *dev;
        struct btrfs_super_block *sb;
@@ -1703,8 +1583,7 @@ int write_all_supers(struct btrfs_fs_info *fs_info)
 
        sb = fs_info->super_copy;
        dev_item = &sb->dev_item;
-       list_for_each(cur, head) {
-               dev = list_entry(cur, struct btrfs_device, dev_list);
+       list_for_each_entry(dev, head, dev_list) {
                if (!dev->writeable)
                        continue;
 
@@ -1760,6 +1639,7 @@ int write_ctree_super(struct btrfs_trans_handle *trans,
 int close_ctree_fs_info(struct btrfs_fs_info *fs_info)
 {
        int ret;
+       int err = 0;
        struct btrfs_trans_handle *trans;
        struct btrfs_root *root = fs_info->tree_root;
 
@@ -1767,8 +1647,13 @@ int close_ctree_fs_info(struct btrfs_fs_info *fs_info)
            fs_info->generation) {
                BUG_ON(!root);
                trans = btrfs_start_transaction(root, 1);
+               if (IS_ERR(trans)) {
+                       err = PTR_ERR(trans);
+                       goto skip_commit;
+               }
                btrfs_commit_transaction(trans, root);
                trans = btrfs_start_transaction(root, 1);
+               BUG_ON(IS_ERR(trans));
                ret = commit_tree_roots(trans, fs_info);
                BUG_ON(ret);
                ret = __commit_transaction(trans, root);
@@ -1785,6 +1670,8 @@ int close_ctree_fs_info(struct btrfs_fs_info *fs_info)
                        fprintf(stderr,
                                "failed to write new super block err %d\n", ret);
        }
+
+skip_commit:
        btrfs_free_block_groups(fs_info);
 
        free_fs_roots_tree(&fs_info->fs_root_tree);
@@ -1793,7 +1680,9 @@ int close_ctree_fs_info(struct btrfs_fs_info *fs_info)
        ret = btrfs_close_devices(fs_info->fs_devices);
        btrfs_cleanup_all_caches(fs_info);
        btrfs_free_fs_info(fs_info);
-       return ret;
+       if (!err)
+               err = ret;
+       return err;
 }
 
 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,