[PATCH 2/9] block: add a bdev_is_partition helper

From: Christoph Hellwig
Date: Thu Sep 03 2020 - 01:42:33 EST


Add a littler helper to make the somewhat arcane bd_contains checks a
little more obvious.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
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(-)

diff --git a/block/blk-lib.c b/block/blk-lib.c
index 0d1811e57ac704..e90614fd8d6a42 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 bdb3bbb253d9f8..e4af3df9d28a68 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 ef722f04f88a93..3bb4571385ce21 100644
--- a/block/scsi_ioctl.c
+++ b/block/scsi_ioctl.c
@@ -854,7 +854,7 @@ 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 09491098047bff..58994da10c0664 100644
--- a/drivers/ide/ide-ioctls.c
+++ b/drivers/ide/ide-ioctls.c
@@ -49,7 +49,7 @@ int ide_setting_ioctl(ide_drive_t *drive, struct block_device *bdev,
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 5edc3079e7c199..af156256e511ff 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 fa313b63413547..8d3df0be0355ce 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 faaf5596e31c12..cb6427fb9f3d16 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 311e5ce80cfc27..a07c39c94bbd03 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 7575fa0aae6e5c..0006a78ebc5dde 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1341,6 +1341,11 @@ 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,
@@ -1457,7 +1462,7 @@ 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;
@@ -1498,7 +1503,7 @@ 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 4b3a42fc3b24f1..157758a88773b9 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);
--
2.28.0