diff options
| author | Dan Williams <dan.j.williams@intel.com> | 2008-04-21 10:51:07 -0700 |
|---|---|---|
| committer | Stephen Rothwell <sfr@canb.auug.org.au> | 2008-06-13 09:28:45 +1000 |
| commit | 35e7929442875f1685f9885c566798d23b360859 (patch) | |
| tree | a370ec51aa5c5ed030e5dd2815fa41a68d3ebcbf /block | |
| parent | 21765aa091fba23ff2c7e0577493a46fcf9b5f97 (diff) | |
sysfs: add /sys/dev/{char,block} to lookup sysfs path by major:minor
Why?:
There are occasions where userspace would like to access sysfs
attributes for a device but it may not know how sysfs has named the
device or the path. For example what is the sysfs path for
/dev/disk/by-id/ata-ST3160827AS_5MT004CK? With this change a call to
stat(2) returns the major:minor then userspace can see that
/sys/dev/block/8:32 links to /sys/block/sdc.
What are the alternatives?:
1/ Add an ioctl to return the path: Doable, but sysfs is meant to reduce
the need to proliferate ioctl interfaces into the kernel, so this
seems counter productive.
2/ Use udev to create these symlinks: Also doable, but it adds a
udev dependency to utilities that might be running in a limited
environment like an initramfs.
3/ Do a full-tree search of sysfs.
[kay.sievers@vrfy.org: fix duplicate registrations]
[kay.sievers@vrfy.org: cleanup suggestions]
Cc: Neil Brown <neilb@suse.de>
Cc: Tejun Heo <htejun@gmail.com>
Acked-by: Kay Sievers <kay.sievers@vrfy.org>
Reviewed-by: SL Baur <steve@xemacs.org>
Acked-by: Kay Sievers <kay.sievers@vrfy.org>
Acked-by: Mark Lord <lkml@rtr.ca>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'block')
| -rw-r--r-- | block/genhd.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/block/genhd.c b/block/genhd.c index b922d4801c87..6b25794f7ec5 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -368,7 +368,10 @@ static struct kobject *base_probe(dev_t devt, int *part, void *data) static int __init genhd_device_init(void) { - int error = class_register(&block_class); + int error; + + block_class.dev_kobj = sysfs_dev_block_kobj; + error = class_register(&block_class); if (unlikely(error)) return error; bdev_map = kobj_map_init(base_probe, &block_class_lock); |