Add mpath_bdev_ioctl() as a multipath block device IOCTL handler. This handler calls into driver mpath_head_template.ioctl handler.
It is expected that the .ioctl handler will unlock the SRCU read lock, as this is what NVMe requires - see nvme_ns_head_ctrl_ioctl(). As such, export a handler to unlock, mpath_head_read_unlock(). The .compat_ioctl handler is given the standard handler. Signed-off-by: John Garry <[email protected]> --- include/linux/multipath.h | 4 ++++ lib/multipath.c | 42 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 46 insertions(+) diff --git a/include/linux/multipath.h b/include/linux/multipath.h index 3846ea8cfd319..40dda6a914c5f 100644 --- a/include/linux/multipath.h +++ b/include/linux/multipath.h @@ -72,6 +72,9 @@ struct mpath_head_template { bool (*is_disabled)(struct mpath_device *); bool (*is_optimized)(struct mpath_device *); enum mpath_access_state (*get_access_state)(struct mpath_device *); + int (*bdev_ioctl)(struct block_device *bdev, struct mpath_device *, + blk_mode_t mode, unsigned int cmd, unsigned long arg, + int srcu_idx); int (*cdev_ioctl)(struct mpath_head *, struct mpath_device *, blk_mode_t mode, unsigned int cmd, unsigned long arg, int srcu_idx); int (*report_zones)(struct mpath_device *, sector_t sector, @@ -154,6 +157,7 @@ void mpath_revalidate_paths(struct mpath_disk *mpath_disk, void mpath_add_sysfs_link(struct mpath_disk *mpath_disk); void mpath_remove_sysfs_link(struct mpath_disk *mpath_disk, struct mpath_device *mpath_device); +void mpath_head_read_unlock(struct mpath_head *mpath_head, int srcu_idx); int mpath_get_head(struct mpath_head *mpath_head); void mpath_put_head(struct mpath_head *mpath_head); void mpath_requeue_work(struct work_struct *work); diff --git a/lib/multipath.c b/lib/multipath.c index 4c57feefff480..537579ad5989e 100644 --- a/lib/multipath.c +++ b/lib/multipath.c @@ -496,6 +496,46 @@ static void mpath_bdev_release(struct gendisk *disk) mpath_put_disk(mpath_disk); } +static int mpath_bdev_ioctl(struct block_device *bdev, blk_mode_t mode, + unsigned int cmd, unsigned long arg) +{ + struct gendisk *disk = bdev->bd_disk; + struct mpath_disk *mpath_disk = mpath_gendisk_to_disk(disk); + struct mpath_head *mpath_head = mpath_disk->mpath_head; + struct mpath_device *mpath_device; + int srcu_idx, err; + + srcu_idx = srcu_read_lock(&mpath_head->srcu); + mpath_device = mpath_find_path(mpath_head); + + if (!mpath_device) { + err = -EWOULDBLOCK; + goto out_unlock; + } + + if (bdev_is_partition(bdev) && !capable(CAP_SYS_RAWIO)) { + err = -ENOIOCTLCMD; + goto out_unlock; + } + + /* ->ioctl must always unlock */ + err = mpath_head->mpdt->bdev_ioctl(bdev, mpath_device, mode, cmd, + arg, srcu_idx); + lockdep_assert_not_held(&mpath_head->srcu); + return err; + +out_unlock: + srcu_read_unlock(&mpath_head->srcu, srcu_idx); + return err; +} + +void mpath_head_read_unlock(struct mpath_head *mpath_head, int srcu_idx) +__releases(&mpath_head->srcu) +{ + srcu_read_unlock(&mpath_head->srcu, srcu_idx); +} +EXPORT_SYMBOL_GPL(mpath_head_read_unlock); + static int mpath_pr_register(struct block_device *bdev, u64 old_key, u64 new_key, unsigned int flags) { @@ -646,6 +686,8 @@ const struct block_device_operations mpath_ops = { .open = mpath_bdev_open, .release = mpath_bdev_release, .submit_bio = mpath_bdev_submit_bio, + .ioctl = mpath_bdev_ioctl, + .compat_ioctl = blkdev_compat_ptr_ioctl, .report_zones = mpath_bdev_report_zones, .pr_ops = &mpath_pr_ops, }; -- 2.43.5
