diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index c1909e5f4506835f7741c5003c51ac65982a3a29..aa1e0ae32943b9b49efc966f1a006f2cc7cf25f3 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -1251,49 +1251,48 @@ void btrfs_release_disk_super(struct btrfs_super_block *super) put_page(page); } -static int btrfs_read_disk_super(struct block_device *bdev, u64 bytenr, - struct page **page, - struct btrfs_super_block **disk_super) +static struct btrfs_super_block *btrfs_read_disk_super(struct block_device *bdev, + u64 bytenr) { + struct btrfs_super_block *disk_super; + struct page *page; void *p; pgoff_t index; /* make sure our super fits in the device */ if (bytenr + PAGE_SIZE >= i_size_read(bdev->bd_inode)) - return 1; + return ERR_PTR(-EINVAL); /* make sure our super fits in the page */ - if (sizeof(**disk_super) > PAGE_SIZE) - return 1; + if (sizeof(*disk_super) > PAGE_SIZE) + return ERR_PTR(-EINVAL); /* make sure our super doesn't straddle pages on disk */ index = bytenr >> PAGE_SHIFT; - if ((bytenr + sizeof(**disk_super) - 1) >> PAGE_SHIFT != index) - return 1; + if ((bytenr + sizeof(*disk_super) - 1) >> PAGE_SHIFT != index) + return ERR_PTR(-EINVAL); /* pull in the page with our super */ - *page = read_cache_page_gfp(bdev->bd_inode->i_mapping, - index, GFP_KERNEL); + page = read_cache_page_gfp(bdev->bd_inode->i_mapping, index, GFP_KERNEL); - if (IS_ERR(*page)) - return 1; + if (IS_ERR(page)) + return ERR_CAST(page); - p = page_address(*page); + p = page_address(page); /* align our pointer to the offset of the super block */ - *disk_super = p + offset_in_page(bytenr); + disk_super = p + offset_in_page(bytenr); - if (btrfs_super_bytenr(*disk_super) != bytenr || - btrfs_super_magic(*disk_super) != BTRFS_MAGIC) { + if (btrfs_super_bytenr(disk_super) != bytenr || + btrfs_super_magic(disk_super) != BTRFS_MAGIC) { btrfs_release_disk_super(p); - return 1; + return ERR_PTR(-EINVAL); } - if ((*disk_super)->label[0] && - (*disk_super)->label[BTRFS_LABEL_SIZE - 1]) - (*disk_super)->label[BTRFS_LABEL_SIZE - 1] = '\0'; + if (disk_super->label[0] && disk_super->label[BTRFS_LABEL_SIZE - 1]) + disk_super->label[BTRFS_LABEL_SIZE - 1] = 0; - return 0; + return disk_super; } int btrfs_forget_devices(const char *path) @@ -1319,7 +1318,6 @@ struct btrfs_device *btrfs_scan_one_device(const char *path, fmode_t flags, bool new_device_added = false; struct btrfs_device *device = NULL; struct block_device *bdev; - struct page *page; u64 bytenr; lockdep_assert_held(&uuid_mutex); @@ -1337,8 +1335,9 @@ struct btrfs_device *btrfs_scan_one_device(const char *path, fmode_t flags, if (IS_ERR(bdev)) return ERR_CAST(bdev); - if (btrfs_read_disk_super(bdev, bytenr, &page, &disk_super)) { - device = ERR_PTR(-EINVAL); + disk_super = btrfs_read_disk_super(bdev, bytenr); + if (IS_ERR(disk_super)) { + device = ERR_CAST(disk_super); goto error_bdev_put; }