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path: root/Documentation/filesystems/sysfs.txt
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2008-07-21sysfs: add /sys/dev/{char,block} to lookup sysfs path by major:minorDan Williams
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>
2008-04-19sysfs: refill attribute buffer when reading from offset 0Dan Williams
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>
2007-10-20docs/sysfs: add missing word to sysfs attribute explanationShaun Zinck
Add the obvious missing word. Signed-off-by: Shaun Zinck <shaun.zinck@gmail.com> Signed-off-by: Adrian Bunk <bunk@kernel.org>
2006-10-03Fix typos in Documentation/: 'D'-'E'Matt LaPlante
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>
2006-04-26[doc] add paragraph about 'fs' subsystem to sysfs.txtMiklos Szeredi
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
2005-09-05[PATCH] Driver core: Documentation: use S_IRUSR | ... in stead of 0644Jan Veldeman
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>
2005-09-05[PATCH] Driver core: Documentation: fix whitespace between parametersJan Veldeman
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>
2005-06-20[PATCH] Driver core: Documentation: update device attribute callbacksYani Ioannou
Signed-off-by: Yani Ioannou <yani.ioannou@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-04-16Linux-2.6.12-rc2Linus Torvalds
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!