From c2b4bb8cb3741c0bacf3683e4c1ecd04c977ada3 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Sun, 23 Aug 2020 11:10:42 +0200 Subject: block: fix locking for struct block_device size updates Two different callers use two different mutexes for updating the block device size, which obviously doesn't help to actually protect against concurrent updates from the different callers. In addition one of the locks, bd_mutex is rather prone to deadlocks with other parts of the block stack that use it for high level synchronization. Switch to using a new spinlock protecting just the size updates, as that is all we need, and make sure everyone does the update through the proper helper. This fixes a bug reported with the nvme revalidating disks during a hot removal operation, which can currently deadlock on bd_mutex. Reported-by: Xianting Tian Signed-off-by: Christoph Hellwig Reviewed-by: Sagi Grimberg Signed-off-by: Jens Axboe --- drivers/s390/block/dasd_ioctl.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-) (limited to 'drivers/s390') diff --git a/drivers/s390/block/dasd_ioctl.c b/drivers/s390/block/dasd_ioctl.c index 777734d1b4e5..faaf5596e31c 100644 --- a/drivers/s390/block/dasd_ioctl.c +++ b/drivers/s390/block/dasd_ioctl.c @@ -55,10 +55,7 @@ dasd_ioctl_enable(struct block_device *bdev) dasd_enable_device(base); /* Formatting the dasd device can change the capacity. */ - mutex_lock(&bdev->bd_mutex); - i_size_write(bdev->bd_inode, - (loff_t)get_capacity(base->block->gdp) << 9); - mutex_unlock(&bdev->bd_mutex); + bd_set_nr_sectors(bdev, get_capacity(base->block->gdp)); dasd_put_device(base); return 0; } @@ -91,9 +88,7 @@ dasd_ioctl_disable(struct block_device *bdev) * Set i_size to zero, since read, write, etc. check against this * value. */ - mutex_lock(&bdev->bd_mutex); - i_size_write(bdev->bd_inode, 0); - mutex_unlock(&bdev->bd_mutex); + bd_set_nr_sectors(bdev, 0); dasd_put_device(base); return 0; } -- cgit v1.2.3 From 841ab72cb5be3bbf6544f28329b81c73f0f835b3 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 21 Sep 2020 09:19:52 +0200 Subject: dasd: cleanup dasd_scan_partitions Use blkdev_get_by_dev instead of bdget_disk + blkdev_get. Signed-off-by: Christoph Hellwig Reviewed-by: Stefan Haberland Signed-off-by: Jens Axboe --- drivers/s390/block/dasd_genhd.c | 15 ++++----------- 1 file changed, 4 insertions(+), 11 deletions(-) (limited to 'drivers/s390') diff --git a/drivers/s390/block/dasd_genhd.c b/drivers/s390/block/dasd_genhd.c index af5b0ecb8f89..a9698fba9b76 100644 --- a/drivers/s390/block/dasd_genhd.c +++ b/drivers/s390/block/dasd_genhd.c @@ -101,18 +101,11 @@ int dasd_scan_partitions(struct dasd_block *block) struct block_device *bdev; int rc; - bdev = bdget_disk(block->gdp, 0); - if (!bdev) { - DBF_DEV_EVENT(DBF_ERR, block->base, "%s", - "scan partitions error, bdget returned NULL"); - return -ENODEV; - } - - rc = blkdev_get(bdev, FMODE_READ, NULL); - if (rc < 0) { + bdev = blkdev_get_by_dev(disk_devt(block->gdp), FMODE_READ, NULL); + if (IS_ERR(bdev)) { DBF_DEV_EVENT(DBF_ERR, block->base, - "scan partitions error, blkdev_get returned %d", - rc); + "scan partitions error, blkdev_get returned %ld", + PTR_ERR(bdev)); return -ENODEV; } -- cgit v1.2.3 From fa01b1e9733fd59ecb8b5b6d85dfb481d2025fbf Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 3 Sep 2020 07:40:57 +0200 Subject: block: add a bdev_is_partition helper Add a littler helper to make the somewhat arcane bd_contains checks a little more obvious. Signed-off-by: Christoph Hellwig Acked-by: Ulf Hansson Signed-off-by: Jens Axboe --- block/blk-lib.c | 2 +- block/ioctl.c | 4 ++-- block/scsi_ioctl.c | 2 +- drivers/ide/ide-ioctls.c | 4 ++-- drivers/md/dm-table.c | 2 +- drivers/mmc/core/block.c | 2 +- drivers/s390/block/dasd_ioctl.c | 8 ++++---- fs/nfsd/blocklayout.c | 4 ++-- include/linux/blkdev.h | 9 +++++++-- kernel/trace/blktrace.c | 2 +- 10 files changed, 22 insertions(+), 17 deletions(-) (limited to 'drivers/s390') diff --git a/block/blk-lib.c b/block/blk-lib.c index 0d1811e57ac7..e90614fd8d6a 100644 --- a/block/blk-lib.c +++ b/block/blk-lib.c @@ -64,7 +64,7 @@ int __blkdev_issue_discard(struct block_device *bdev, sector_t sector, return -EINVAL; /* In case the discard request is in a partition */ - if (bdev->bd_partno) + if (bdev_is_partition(bdev)) part_offset = bdev->bd_part->start_sect; while (nr_sects) { diff --git a/block/ioctl.c b/block/ioctl.c index 06262c28f0c6..3fbc382eb926 100644 --- a/block/ioctl.c +++ b/block/ioctl.c @@ -23,7 +23,7 @@ static int blkpg_do_ioctl(struct block_device *bdev, return -EACCES; if (copy_from_user(&p, upart, sizeof(struct blkpg_partition))) return -EFAULT; - if (bdev != bdev->bd_contains) + if (bdev_is_partition(bdev)) return -EINVAL; if (p.pno <= 0) @@ -94,7 +94,7 @@ static int blkdev_reread_part(struct block_device *bdev) { int ret; - if (!disk_part_scan_enabled(bdev->bd_disk) || bdev != bdev->bd_contains) + if (!disk_part_scan_enabled(bdev->bd_disk) || bdev_is_partition(bdev)) return -EINVAL; if (!capable(CAP_SYS_ADMIN)) return -EACCES; diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c index 4421e61c1af1..d4abd1ed5a2d 100644 --- a/block/scsi_ioctl.c +++ b/block/scsi_ioctl.c @@ -852,7 +852,7 @@ EXPORT_SYMBOL(scsi_cmd_ioctl); int scsi_verify_blk_ioctl(struct block_device *bd, unsigned int cmd) { - if (bd && bd == bd->bd_contains) + if (bd && !bdev_is_partition(bd)) return 0; if (capable(CAP_SYS_RAWIO)) diff --git a/drivers/ide/ide-ioctls.c b/drivers/ide/ide-ioctls.c index 09491098047b..58994da10c06 100644 --- a/drivers/ide/ide-ioctls.c +++ b/drivers/ide/ide-ioctls.c @@ -49,7 +49,7 @@ read_val: return err >= 0 ? put_user_long(err, arg) : err; set_val: - if (bdev != bdev->bd_contains) + if (bdev_is_partition(bdev)) err = -EINVAL; else { if (!capable(CAP_SYS_ADMIN)) @@ -257,7 +257,7 @@ int generic_ide_ioctl(ide_drive_t *drive, struct block_device *bdev, switch (cmd) { case HDIO_OBSOLETE_IDENTITY: case HDIO_GET_IDENTITY: - if (bdev != bdev->bd_contains) + if (bdev_is_partition(bdev)) return -EINVAL; return ide_get_identity_ioctl(drive, cmd, argp); case HDIO_GET_NICE: diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index 405d7cf10eb9..12d909044c10 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -903,7 +903,7 @@ static int device_is_rq_stackable(struct dm_target *ti, struct dm_dev *dev, struct request_queue *q = bdev_get_queue(bdev); /* request-based cannot stack on partitions! */ - if (bdev != bdev->bd_contains) + if (bdev_is_partition(bdev)) return false; return queue_is_mq(q); diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c index fa313b634135..8d3df0be0355 100644 --- a/drivers/mmc/core/block.c +++ b/drivers/mmc/core/block.c @@ -723,7 +723,7 @@ static int mmc_blk_check_blkdev(struct block_device *bdev) * whole block device, not on a partition. This prevents overspray * between sibling partitions. */ - if ((!capable(CAP_SYS_RAWIO)) || (bdev != bdev->bd_contains)) + if (!capable(CAP_SYS_RAWIO) || bdev_is_partition(bdev)) return -EPERM; return 0; } diff --git a/drivers/s390/block/dasd_ioctl.c b/drivers/s390/block/dasd_ioctl.c index faaf5596e31c..cb6427fb9f3d 100644 --- a/drivers/s390/block/dasd_ioctl.c +++ b/drivers/s390/block/dasd_ioctl.c @@ -277,7 +277,7 @@ dasd_ioctl_format(struct block_device *bdev, void __user *argp) dasd_put_device(base); return -EFAULT; } - if (bdev != bdev->bd_contains) { + if (bdev_is_partition(bdev)) { pr_warn("%s: The specified DASD is a partition and cannot be formatted\n", dev_name(&base->cdev->dev)); dasd_put_device(base); @@ -304,7 +304,7 @@ static int dasd_ioctl_check_format(struct block_device *bdev, void __user *argp) base = dasd_device_from_gendisk(bdev->bd_disk); if (!base) return -ENODEV; - if (bdev != bdev->bd_contains) { + if (bdev_is_partition(bdev)) { pr_warn("%s: The specified DASD is a partition and cannot be checked\n", dev_name(&base->cdev->dev)); rc = -EINVAL; @@ -362,7 +362,7 @@ static int dasd_ioctl_release_space(struct block_device *bdev, void __user *argp rc = -EROFS; goto out_err; } - if (bdev != bdev->bd_contains) { + if (bdev_is_partition(bdev)) { pr_warn("%s: The specified DASD is a partition and tracks cannot be released\n", dev_name(&base->cdev->dev)); rc = -EINVAL; @@ -540,7 +540,7 @@ dasd_ioctl_set_ro(struct block_device *bdev, void __user *argp) if (!capable(CAP_SYS_ADMIN)) return -EACCES; - if (bdev != bdev->bd_contains) + if (bdev_is_partition(bdev)) // ro setting is not allowed for partitions return -EINVAL; if (get_user(intval, (int __user *)argp)) diff --git a/fs/nfsd/blocklayout.c b/fs/nfsd/blocklayout.c index 311e5ce80cfc..a07c39c94bbd 100644 --- a/fs/nfsd/blocklayout.c +++ b/fs/nfsd/blocklayout.c @@ -170,7 +170,7 @@ nfsd4_block_proc_getdeviceinfo(struct super_block *sb, struct nfs4_client *clp, struct nfsd4_getdeviceinfo *gdp) { - if (sb->s_bdev != sb->s_bdev->bd_contains) + if (bdev_is_partition(sb->s_bdev)) return nfserr_inval; return nfserrno(nfsd4_block_get_device_info_simple(sb, gdp)); } @@ -382,7 +382,7 @@ nfsd4_scsi_proc_getdeviceinfo(struct super_block *sb, struct nfs4_client *clp, struct nfsd4_getdeviceinfo *gdp) { - if (sb->s_bdev != sb->s_bdev->bd_contains) + if (bdev_is_partition(sb->s_bdev)) return nfserr_inval; return nfserrno(nfsd4_block_get_device_info_scsi(sb, clp, gdp)); } diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 8e77f12de522..33f283885ba5 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1353,6 +1353,11 @@ static inline int sb_issue_zeroout(struct super_block *sb, sector_t block, extern int blk_verify_command(unsigned char *cmd, fmode_t mode); +static inline bool bdev_is_partition(struct block_device *bdev) +{ + return bdev->bd_partno; +} + enum blk_default_limits { BLK_MAX_SEGMENTS = 128, BLK_SAFE_MAX_SECTORS = 255, @@ -1469,7 +1474,7 @@ static inline int bdev_alignment_offset(struct block_device *bdev) if (q->limits.misaligned) return -1; - if (bdev != bdev->bd_contains) + if (bdev_is_partition(bdev)) return queue_limit_alignment_offset(&q->limits, bdev->bd_part->start_sect); return q->limits.alignment_offset; @@ -1510,7 +1515,7 @@ static inline int bdev_discard_alignment(struct block_device *bdev) { struct request_queue *q = bdev_get_queue(bdev); - if (bdev != bdev->bd_contains) + if (bdev_is_partition(bdev)) return queue_limit_discard_alignment(&q->limits, bdev->bd_part->start_sect); return q->limits.discard_alignment; diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c index c0887f32f647..ec874ea04092 100644 --- a/kernel/trace/blktrace.c +++ b/kernel/trace/blktrace.c @@ -527,7 +527,7 @@ static int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev, * and scsi-generic block devices we create a temporary new debugfs * directory that will be removed once the trace ends. */ - if (bdev && bdev == bdev->bd_contains) + if (bdev && !bdev_is_partition(bdev)) dir = q->debugfs_dir; else bt->dir = dir = debugfs_create_dir(buts->name, blk_debugfs_root); -- cgit v1.2.3