Re: [PATCH 01/32] block: Provide blkdev_get_handle_* functions
From: Keith Busch <kbusch@kernel.org>
Date: 2023-07-04 16:28:48
Also in:
dm-devel, linux-bcache, linux-block, linux-btrfs, linux-ext4, linux-f2fs-devel, linux-fsdevel, linux-mm, linux-nfs, linux-nvme, linux-pm, linux-s390, linux-scsi, linux-xfs, target-devel, xen-devel
On Tue, Jul 04, 2023 at 02:21:28PM +0200, Jan Kara wrote:
+struct bdev_handle *blkdev_get_handle_by_dev(dev_t dev, blk_mode_t mode,
+ void *holder, const struct blk_holder_ops *hops)
+{
+ struct bdev_handle *handle = kmalloc(sizeof(struct bdev_handle),
+ GFP_KERNEL);I believe 'sizeof(*handle)' is the preferred style.
+ struct block_device *bdev; + + if (!handle) + return ERR_PTR(-ENOMEM); + bdev = blkdev_get_by_dev(dev, mode, holder, hops); + if (IS_ERR(bdev)) + return ERR_CAST(bdev);
Need a 'kfree(handle)' before the error return. Or would it be simpler to get the bdev first so you can check the mode settings against a read-only bdev prior to the kmalloc?
quoted hunk ↗ jump to hunk
+ handle->bdev = bdev; + handle->holder = holder; + return handle; +} +EXPORT_SYMBOL(blkdev_get_handle_by_dev); + /** * blkdev_get_by_path - open a block device by name * @path: path to the block device to open@@ -884,6 +902,28 @@ struct block_device *blkdev_get_by_path(const char *path, blk_mode_t mode, } EXPORT_SYMBOL(blkdev_get_by_path); +struct bdev_handle *blkdev_get_handle_by_path(const char *path, blk_mode_t mode, + void *holder, const struct blk_holder_ops *hops) +{ + struct bdev_handle *handle; + dev_t dev; + int error; + + error = lookup_bdev(path, &dev); + if (error) + return ERR_PTR(error); + + handle = blkdev_get_handle_by_dev(dev, mode, holder, hops); + if (!IS_ERR(handle) && (mode & BLK_OPEN_WRITE) && + bdev_read_only(handle->bdev)) { + blkdev_handle_put(handle); + return ERR_PTR(-EACCES); + } + + return handle; +} +EXPORT_SYMBOL(blkdev_get_handle_by_path);