Changed the documentation to allow sprintf() when the buffer
provided by sysfs cannot be overflowed. Explicitly say
snprintf() must never be used in a show function to format
data to be returned to user space.
Change based on a discussion about the patch
st: convert DRIVER_ATTR macros to DRIVER_ATTR_RO
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Shane Seymour <shane.seymour@hp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Although it is expected nowadays that every new sysfs attribute is
documented under Documentation/ABI, this is not yet mentioned in the
kernel documentation. This patch adds a note in the sysfs
documentation about that requirement.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Since snprintf() may return a value that exceeds its second argument,
show() methods should use scnprintf() instead of snprintf(). This patch
updates the example in the sysfs documentation accordingly.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Some time ago the way how sysfs stores a pointer to a kobject
corresponding to a directory was modified. This patch brings the
documentation again in sync with the implementation.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Fix all discrepancies I know of between the sysfs implementation and its
documentation.
Signed-off-by: Bart Van Assche <bart.vanassche@gmail.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Many struct driver_attribute descriptors are purely read-only
structures, and there's no need to change them. Therefore make
the promise not to, which will let those descriptors be put in
a ro section.
Signed-off-by: Phil Carmody <ext-phil.2.carmody@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Most device_attributes are const, and are begging to be
put in a ro section. However, the create and remove
file interfaces were failing to propagate the const promise
which the only functions they call offer.
Signed-off-by: Phil Carmody <ext-phil.2.carmody@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The original text suggested that sysfs is mandatory and always
compiled in the kernel.
Signed-off-by: Lucian Adrian Grijincu <lgrijincu@ixiacom.com>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Fix descriptions of device attributes to be consistent with the actual
implementations in include/linux/device.h
Signed-off-by: Mike Murphy <mamurph[at]cs.clemson.edu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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>
Requiring userspace to close and re-open sysfs attributes has been the
policy since before 2.6.12. It allows userspace to get a consistent
snapshot of kernel state and consume it with incremental reads and seeks.
Now, if the file position is zero the kernel assumes userspace wants to see
the new value. The application for this change is to allow a userspace
RAID metadata handler to check the state of an array without causing any
memory allocations. Thus not causing writeback to a raid array that might
be blocked waiting for userspace to take action.
Cc: Neil Brown <neilb@suse.de>
Acked-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch fixes typos in various Documentation txts. This patch addresses
some words starting with the letters 'D'-'E'.
Signed-off-by: Matt LaPlante <kernel1@cyberdogtech.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Change filemode to use defines in stead of 0644,
based on suggestions by Walter Harms and Domen Puncer.
Signed-off-by: Jan Veldeman <Jan.Veldeman@advalvas.be>
Signed-off-by: Domen Puncer <domen@coderock.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Fix whitespace after comma between parameters.
Signed-off-by: Jan Veldeman <Jan.Veldeman@advalvas.be>
Signed-off-by: Domen Puncer <domen@coderock.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
