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 <hch@lst.de>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/blk-lib.c b/block/blk-lib.c
index 0d1811e..e90614f 100644 (file)
--- 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 06262c2..3fbc382 100644 (file)
--- 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 4421e61..d4abd1e 100644 (file)
--- 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 0949109..58994da 100644 (file)
--- 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 405d7cf..12d9090 100644 (file)
--- 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 fa313b6..8d3df0b 100644 (file)
--- 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 faaf559..cb6427f 100644 (file)
--- 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 311e5ce..a07c39c 100644 (file)
--- 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 8e77f12..33f2838 100644 (file)
--- 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 c0887f3..ec874ea 100644 (file)
--- 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);