From d27769ec3df1a8de9ca450d2dcd72d1ab259ba32 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 23 Aug 2011 20:01:04 +0200 Subject: block: add GENHD_FL_NO_PART_SCAN There are cases where suppressing partition scan is useful - e.g. for lo devices and pseudo SATA devices which advertise to be a disk but get upset on partition scan (some port multiplier control devices show such behavior). This patch adds GENHD_FL_NO_PART_SCAN which suppresses partition scan regardless of the number of possible partitions. disk_partitionable() is renamed to disk_part_scan_enabled() as suppressing partition scan doesn't imply the device can't be partitioned using BLKPG_ADD/DEL_PARTITION calls from userland. show_partition() now directly tests disk_max_parts() to maintain backward-compatibility. -v2: Updated to make it clear that only partition scan is suppressed not partitioning itself as suggested by Kay Sievers. Signed-off-by: Tejun Heo Cc: Kay Sievers Signed-off-by: Jens Axboe --- block/genhd.c | 4 ++-- block/ioctl.c | 2 +- fs/block_dev.c | 2 +- include/linux/genhd.h | 6 ++++-- 4 files changed, 8 insertions(+), 6 deletions(-) diff --git a/block/genhd.c b/block/genhd.c index 5cb51c5..2429ecb 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -536,7 +536,7 @@ void register_disk(struct gendisk *disk) disk->slave_dir = kobject_create_and_add("slaves", &ddev->kobj); /* No minors to use for partitions */ - if (!disk_partitionable(disk)) + if (!disk_part_scan_enabled(disk)) goto exit; /* No such device (e.g., media were just removed) */ @@ -841,7 +841,7 @@ static int show_partition(struct seq_file *seqf, void *v) char buf[BDEVNAME_SIZE]; /* Don't show non-partitionable removeable devices or empty devices */ - if (!get_capacity(sgp) || (!disk_partitionable(sgp) && + if (!get_capacity(sgp) || (!disk_max_parts(sgp) && (sgp->flags & GENHD_FL_REMOVABLE))) return 0; if (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO) diff --git a/block/ioctl.c b/block/ioctl.c index 1124cd2..5c74efc 100644 --- a/block/ioctl.c +++ b/block/ioctl.c @@ -101,7 +101,7 @@ static int blkdev_reread_part(struct block_device *bdev) struct gendisk *disk = bdev->bd_disk; int res; - if (!disk_partitionable(disk) || bdev != bdev->bd_contains) + if (!disk_part_scan_enabled(disk) || bdev != bdev->bd_contains) return -EINVAL; if (!capable(CAP_SYS_ADMIN)) return -EACCES; diff --git a/fs/block_dev.c b/fs/block_dev.c index ff77262..0bed0d4 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -971,7 +971,7 @@ static void flush_disk(struct block_device *bdev, bool kill_dirty) if (!bdev->bd_disk) return; - if (disk_partitionable(bdev->bd_disk)) + if (disk_part_scan_enabled(bdev->bd_disk)) bdev->bd_invalidated = 1; } diff --git a/include/linux/genhd.h b/include/linux/genhd.h index 02fa469..6d18f35 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -128,6 +128,7 @@ struct hd_struct { #define GENHD_FL_EXT_DEVT 64 /* allow extended devt */ #define GENHD_FL_NATIVE_CAPACITY 128 #define GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE 256 +#define GENHD_FL_NO_PART_SCAN 512 enum { DISK_EVENT_MEDIA_CHANGE = 1 << 0, /* media changed */ @@ -234,9 +235,10 @@ static inline int disk_max_parts(struct gendisk *disk) return disk->minors; } -static inline bool disk_partitionable(struct gendisk *disk) +static inline bool disk_part_scan_enabled(struct gendisk *disk) { - return disk_max_parts(disk) > 1; + return disk_max_parts(disk) > 1 && + !(disk->flags & GENHD_FL_NO_PART_SCAN); } static inline dev_t disk_devt(struct gendisk *disk) -- cgit v1.1