From f0b870df80bc70dad432fd0c142bb709a49964f5 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 14 Nov 2019 15:34:36 +0100 Subject: [PATCH] block: remove (__)blkdev_reread_part as an exported API In general drivers should never mess with partition tables directly. Unfortunately s390 and loop do for somewhat historic reasons, but they can use bdev_disk_changed directly instead when we export it as they satisfy the sanity checks we have in __blkdev_reread_part. Signed-off-by: Christoph Hellwig Reviewed-by: Stefan Haberland [dasd] Reviewed-by: Jan Kara Signed-off-by: Jens Axboe --- block/ioctl.c | 35 +++++---------------------------- drivers/block/loop.c | 13 +++++++----- drivers/s390/block/dasd_genhd.c | 4 +++- fs/block_dev.c | 7 +++++++ include/linux/fs.h | 2 -- 5 files changed, 23 insertions(+), 38 deletions(-) diff --git a/block/ioctl.c b/block/ioctl.c index 5ccd9f016594..7ac8a66c9787 100644 --- a/block/ioctl.c +++ b/block/ioctl.c @@ -155,46 +155,21 @@ static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user } } -/* - * This is an exported API for the block driver, and will not - * acquire bd_mutex. This API should be used in case that - * caller has held bd_mutex already. - */ -int __blkdev_reread_part(struct block_device *bdev) +static int blkdev_reread_part(struct block_device *bdev) { + int ret; + if (!disk_part_scan_enabled(bdev->bd_disk) || bdev != bdev->bd_contains) return -EINVAL; if (!capable(CAP_SYS_ADMIN)) return -EACCES; - lockdep_assert_held(&bdev->bd_mutex); - - return bdev_disk_changed(bdev, false); -} -EXPORT_SYMBOL(__blkdev_reread_part); - -/* - * This is an exported API for the block driver, and will - * try to acquire bd_mutex. If bd_mutex has been held already - * in current context, please call __blkdev_reread_part(). - * - * Make sure the held locks in current context aren't required - * in open()/close() handler and I/O path for avoiding ABBA deadlock: - * - bd_mutex is held before calling block driver's open/close - * handler - * - reading partition table may submit I/O to the block device - */ -int blkdev_reread_part(struct block_device *bdev) -{ - int res; - mutex_lock(&bdev->bd_mutex); - res = __blkdev_reread_part(bdev); + ret = bdev_disk_changed(bdev, false); mutex_unlock(&bdev->bd_mutex); - return res; + return ret; } -EXPORT_SYMBOL(blkdev_reread_part); static int blk_ioctl_discard(struct block_device *bdev, fmode_t mode, unsigned long arg, unsigned long flags) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index ef6e251857c8..739b372a5112 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -640,7 +640,9 @@ static void loop_reread_partitions(struct loop_device *lo, { int rc; - rc = blkdev_reread_part(bdev); + mutex_lock(&bdev->bd_mutex); + rc = bdev_disk_changed(bdev, false); + mutex_unlock(&bdev->bd_mutex); if (rc) pr_warn("%s: partition scan of loop%d (%s) failed (rc=%d)\n", __func__, lo->lo_number, lo->lo_file_name, rc); @@ -1164,10 +1166,11 @@ out_unlock: * must be at least one and it can only become zero when the * current holder is released. */ - if (release) - err = __blkdev_reread_part(bdev); - else - err = blkdev_reread_part(bdev); + if (!release) + mutex_lock(&bdev->bd_mutex); + err = bdev_disk_changed(bdev, false); + if (!release) + mutex_unlock(&bdev->bd_mutex); if (err) pr_warn("%s: partition scan of loop%d failed (rc=%d)\n", __func__, lo_number, err); diff --git a/drivers/s390/block/dasd_genhd.c b/drivers/s390/block/dasd_genhd.c index 5542d9eadfe0..7d079154f849 100644 --- a/drivers/s390/block/dasd_genhd.c +++ b/drivers/s390/block/dasd_genhd.c @@ -116,7 +116,9 @@ int dasd_scan_partitions(struct dasd_block *block) return -ENODEV; } - rc = blkdev_reread_part(bdev); + mutex_lock(&bdev->bd_mutex); + rc = bdev_disk_changed(bdev, false); + mutex_unlock(&bdev->bd_mutex); if (rc) DBF_DEV_EVENT(DBF_ERR, block->base, "scan partitions error, rc %d", rc); diff --git a/fs/block_dev.c b/fs/block_dev.c index ae16466a67f7..9558a2f064b1 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -1513,6 +1513,8 @@ int bdev_disk_changed(struct block_device *bdev, bool invalidate) struct gendisk *disk = bdev->bd_disk; int ret; + lockdep_assert_held(&bdev->bd_mutex); + rescan: ret = blk_drop_partitions(disk, bdev); if (ret) @@ -1540,6 +1542,11 @@ rescan: return ret; } +/* + * Only exported for for loop and dasd for historic reasons. Don't use in new + * code! + */ +EXPORT_SYMBOL_GPL(bdev_disk_changed); /* * bd_mutex locking: diff --git a/include/linux/fs.h b/include/linux/fs.h index d233dd661df7..ae6c5c37f3ae 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2632,8 +2632,6 @@ extern void bd_finish_claiming(struct block_device *bdev, extern void bd_abort_claiming(struct block_device *bdev, struct block_device *whole, void *holder); extern void blkdev_put(struct block_device *bdev, fmode_t mode); -extern int __blkdev_reread_part(struct block_device *bdev); -extern int blkdev_reread_part(struct block_device *bdev); #ifdef CONFIG_SYSFS extern int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk);