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path: root/fs/sysfs/file.c
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2013-09-26sysfs: @name comes before @nsTejun Heo
Some internal sysfs functions which take explicit namespace argument are weird in that they place the optional @ns in front of @name which is contrary to the established convention. This is confusing and error-prone especially as @ns and @name may be interchanged without causing compilation warning. Swap the positions of @name and @ns in the following internal functions. sysfs_find_dirent() sysfs_rename() sysfs_hash_and_remove() sysfs_name_hash() sysfs_name_compare() create_dir() This patch doesn't introduce any functional changes. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Kay Sievers <kay@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-09-26sysfs: clean up sysfs_get_dirent()Tejun Heo
The pre-existing sysfs interfaces which take explicit namespace argument are weird in that they place the optional @ns in front of @name which is contrary to the established convention. For example, we end up forcing vast majority of sysfs_get_dirent() users to do sysfs_get_dirent(parent, NULL, name), which is silly and error-prone especially as @ns and @name may be interchanged without causing compilation warning. This renames sysfs_get_dirent() to sysfs_get_dirent_ns() and swap the positions of @name and @ns, and sysfs_get_dirent() is now a wrapper around sysfs_get_dirent_ns(). This makes confusions a lot less likely. There are other interfaces which take @ns before @name. They'll be updated by following patches. This patch doesn't introduce any functional changes. v2: EXPORT_SYMBOL_GPL() wasn't updated leading to undefined symbol error on module builds. Reported by build test robot. Fixed. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Kay Sievers <kay@vrfy.org> Cc: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-09-26sysfs: make attr namespace interface less convolutedTejun Heo
sysfs ns (namespace) implementation became more convoluted than necessary while trying to hide ns information from visible interface. The relatively recent attr ns support is a good example. * attr ns tag is determined by sysfs_ops->namespace() callback while dir tag is determined by kobj_type->namespace(). The placement is arbitrary. * Instead of performing operations with explicit ns tag, the namespace callback is routed through sysfs_attr_ns(), sysfs_ops->namespace(), class_attr_namespace(), class_attr->namespace(). It's not simpler in any sense. The only thing this convolution does is traversing the whole stack backwards. The namespace callbacks are unncessary because the operations involved are inherently synchronous. The information can be provided in in straight-forward top-down direction and reversing that direction is unnecessary and against basic design principles. This backward interface is unnecessarily convoluted and hinders properly separating out sysfs from driver model / kobject for proper layering. This patch updates attr ns support such that * sysfs_ops->namespace() and class_attr->namespace() are dropped. * sysfs_{create|remove}_file_ns(), which take explicit @ns param, are added and sysfs_{create|remove}_file() are now simple wrappers around the ns aware functions. * ns handling is dropped from sysfs_chmod_file(). Nobody uses it at this point. sysfs_chmod_file_ns() can be added later if necessary. * Explicit @ns is propagated through class_{create|remove}_file_ns() and netdev_class_{create|remove}_file_ns(). * driver/net/bonding which is currently the only user of attr namespace is updated to use netdev_class_{create|remove}_file_ns() with @bh->net as the ns tag instead of using the namespace callback. This patch should be an equivalent conversion without any functional difference. It makes the code easier to follow, reduces lines of code a bit and helps proper separation and layering. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Kay Sievers <kay@vrfy.org> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-21sysfs: file.c: fix up broken string warningsGreg Kroah-Hartman
This fixes the coding style warnings in fs/sysfs/file.c for broken strings across lines. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-21sysfs: fix up uaccess.h coding style warningsGreg Kroah-Hartman
This fixes the uaccess.h warnings in the sysfs.c files. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-21sysfs: fix up 80 column coding style issuesGreg Kroah-Hartman
This fixes up the 80 column coding style issues in the sysfs .c files. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-21sysfs: fix up space coding style issuesGreg Kroah-Hartman
This fixes up all of the space-related coding style issues for the sysfs code. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-21sysfs: remove trailing whitespaceGreg Kroah-Hartman
This removes all trailing whitespace errors in the sysfs code. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-21sysfs: fix placement of EXPORT_SYMBOL()Greg Kroah-Hartman
The export should happen after the function, not at the bottom of the file, so fix that up. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-06-07sysfs_notify is only possible on file attributesNick Dyer
If sysfs_notify is called on a binary attribute, bad things can happen, so prevent it. Note, no in-kernel usage of this is currently present, but in the future, it's good to be safe. Changes in V2: - Also ignore sysfs_notify on dirs, links - Use WARN_ON rather than silently failing - Compiled and tested (huge apologies about first submission) Signed-off-by: Nick Dyer <nick.dyer@itdev.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-26sysfs: Mark sysfs_attr_ns staticJosh Triplett
Nothing outside of fs/sysfs/file.c references this function, so mark it static. Signed-off-by: Josh Triplett <josh@joshtriplett.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-01-24sysfs: Complain bitterly about attempts to remove files from nonexistent ↵Eric W. Biederman
directories. Recently an OOPS was observed from the usb serial io_ti driver when it tried to remove sysfs directories. Upon investigation it turns out this driver was always buggy and that a recent sysfs change had stopped guarding itself against removing attributes from sysfs directories that had already been removed. :( Historically we have been silent about attempting to files from nonexistent sysfs directories and have politely returned error codes. That has resulted in people writing broken code that ignores the error codes. Issue a kernel WARNING and a stack backtrace to make it clear in no uncertain terms that abusing sysfs is not ok, and the callers need to fix their code. This change transforms the io_ti OOPS into a more comprehensible error message and stack backtrace. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Reported-by: Wolfgang Frisch <wfpub@roembden.net> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2012-01-03sysfs: propagate umode_tAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-03switch sysfs_chmod_file() to umode_tAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-10-19sysfs: Reject with a warning invalid uses of tagged directories.Eric W. Biederman
sysfs is a core piece of ifrastructure that many people use and few people have all of the rules in their head on how to use it correctly. Add warnings for people using tagged directories improperly to that any misuses can be caught and diagnosed quickly. A single inexpensive test in sysfs_find_dirent is almost sufficient to catch all possible misuses. An additional warning is needed in sysfs_add_dirent so that we actually fail when attempting to add an untagged dirent in a tagged directory. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-10-19sysfs: Implement support for tagged files in sysfs.Eric W. Biederman
Looking up files in sysfs is hard to understand and analyize because we currently allow placing untagged files in tagged directories. In the implementation of that we have two subtly different meanings of NULL. NULL meaning there is no tag on a directory entry and NULL meaning we don't care which namespace the lookup is performed for. This multiple uses of NULL have resulted in subtle bugs (since fixed) in the code. Currently it is only the bonding driver that needs to have an untagged file in a tagged directory. To untagle this mess I am adding support for tagged files to sysfs. Modifying the bonding driver to implement bonding_masters as a tagged file. Registering bonding_masters once for each network namespace. Then I am removing support for untagged entries in tagged sysfs directories. Resulting in code that is much easier to reason about. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-13sysfs: remove "last sysfs file:" line from the oops messagesGreg Kroah-Hartman
On some arches (x86, sh, arm, unicore, powerpc) the oops message would print out the last sysfs file accessed. This was very useful in finding a number of sysfs and driver core bugs in the 2.5 and early 2.6 development days, but it has been a number of years since this file has actually helped in debugging anything that couldn't also be trivially determined from the stack traceback. So it's time to delete the line. This is good as we need all the space we can get for oops messages at times on consoles. Acked-by: Phil Carmody <ext-phil.2.carmody@nokia.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-09-03sysfs: checking for NULL instead of ERR_PTRDan Carpenter
d_path() returns an ERR_PTR and it doesn't return NULL. Signed-off-by: Dan Carpenter <error27@gmail.com> Cc: stable <stable@kernel.org> Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-08-05sysfs: sysfs_chmod_file's attr can be constJean Delvare
sysfs_chmod_file doesn't change the attribute it operates on, so this attribute can be marked const. Signed-off-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-21sysfs: Implement sysfs tagged directory support.Eric W. Biederman
The problem. When implementing a network namespace I need to be able to have multiple network devices with the same name. Currently this is a problem for /sys/class/net/*, /sys/devices/virtual/net/*, and potentially a few other directories of the form /sys/ ... /net/*. What this patch does is to add an additional tag field to the sysfs dirent structure. For directories that should show different contents depending on the context such as /sys/class/net/, and /sys/devices/virtual/net/ this tag field is used to specify the context in which those directories should be visible. Effectively this is the same as creating multiple distinct directories with the same name but internally to sysfs the result is nicer. I am calling the concept of a single directory that looks like multiple directories all at the same path in the filesystem tagged directories. For the networking namespace the set of directories whose contents I need to filter with tags can depend on the presence or absence of hotplug hardware or which modules are currently loaded. Which means I need a simple race free way to setup those directories as tagged. To achieve a reace free design all tagged directories are created and managed by sysfs itself. Users of this interface: - define a type in the sysfs_tag_type enumeration. - call sysfs_register_ns_types with the type and it's operations - sysfs_exit_ns when an individual tag is no longer valid - Implement mount_ns() which returns the ns of the calling process so we can attach it to a sysfs superblock. - Implement ktype.namespace() which returns the ns of a syfs kobject. Everything else is left up to sysfs and the driver layer. For the network namespace mount_ns and namespace() are essentially one line functions, and look to remain that. Tags are currently represented a const void * pointers as that is both generic, prevides enough information for equality comparisons, and is trivial to create for current users, as it is just the existing namespace pointer. The work needed in sysfs is more extensive. At each directory or symlink creating I need to check if the directory it is being created in is a tagged directory and if so generate the appropriate tag to place on the sysfs_dirent. Likewise at each symlink or directory removal I need to check if the sysfs directory it is being removed from is a tagged directory and if so figure out which tag goes along with the name I am deleting. Currently only directories which hold kobjects, and symlinks are supported. There is not enough information in the current file attribute interfaces to give us anything to discriminate on which makes it useless, and there are no potential users which makes it an uninteresting problem to solve. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Benjamin Thery <benjamin.thery@bull.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-03-07sysfs: Only take active references on attributes.Eric W. Biederman
If we exclude directories and symlinks from the set of sysfs dirents where we need active references we are left with sysfs attributes (binary or not). - Tweak sysfs_deactivate to only do something on attributes - Move lockdep initialization into sysfs_file_add_mode to limit it to just attributes. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: WANG Cong <xiyou.wangcong@gmail.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-03-07sysfs: Remove sysfs_get/put_active_twoEric W. Biederman
It turns out that holding an active reference on a directory is pointless. The purpose of the active references are to allows us to block when removing sysfs entries that have custom methods so we don't remove modules while running modular code and to keep those custom methods from accessing data structures after the files have been removed. Further sysfs_remove_dir remove all elements in the directory before removing the directory itself, so there is no chance we will remove a directory with active children. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-03-07Driver core: Constify struct sysfs_ops in struct kobj_typeEmese Revfy
Constify struct sysfs_ops. This is part of the ops structure constification effort started by Arjan van de Ven et al. Benefits of this constification: * prevents modification of data that is shared (referenced) by many other structure instances at runtime * detects/prevents accidental (but not intentional) modification attempts on archs that enforce read-only kernel data at runtime * potentially better optimized code as the compiler can assume that the const data cannot be changed * the compiler/linker move const data into .rodata and therefore exclude them from false sharing Signed-off-by: Emese Revfy <re.emese@gmail.com> Acked-by: David Teigland <teigland@redhat.com> Acked-by: Matt Domsch <Matt_Domsch@dell.com> Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Acked-by: Hans J. Koch <hjk@linutronix.de> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Acked-by: Jens Axboe <jens.axboe@oracle.com> Acked-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-03-07sysfs: Add sysfs_add/remove_files utility functionsAndi Kleen
Adding/Removing a whole array of attributes is very common. Add a standard utility function to do this with a simple function call, instead of requiring drivers to open code this. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-12-11sysfs: In sysfs_chmod_file lazily propagate the mode change.Eric W. Biederman
Now that sysfs_getattr and sysfs_permission refresh the vfs inode there is no need to immediatly push the mode change into the vfs cache. Reducing the amount of work needed and simplifying the locking. Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-12-11sysfs: Simplify sysfs_chmod_file semanticsEric W. Biederman
Currently every caller of sysfs_chmod_file happens at either file creation time to set a non-default mode or in response to a specific user requested space change in policy. Making timestamps of when the chmod happens and notification of a file changing mode uninteresting. Remove the unnecessary time stamp and filesystem change notification, and removes the last of the explicit inotify and donitfy support from sysfs. Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-10-14sysfs: Allow sysfs_notify_dirent to be called from interrupt context.Neil Brown
sysfs_notify_dirent is a simple atomic operation that can be used to alert user-space that new data can be read from a sysfs attribute. Unfortunately it cannot currently be called from non-process context because of its use of spin_lock which is sometimes taken with interrupts enabled. So change all lockers of sysfs_open_dirent_lock to disable interrupts, thus making sysfs_notify_dirent safe to be called from non-process context (as drivers/md does in md_safemode_timeout). sysfs_get_open_dirent is (documented as being) only called from process context, so it uses spin_lock_irq. Other places use spin_lock_irqsave. The usage for sysfs_notify_dirent in md_safemode_timeout was introduced in 2.6.28, so this patch is suitable for that and more recent kernels. Reported-by: Joel Andres Granados <jgranado@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-05-28sysfs: file.c: use create_singlethread_workqueue()Andrew Morton
We don't need a kernel thread per CPU for this application. Acked-by: Alex Chiang <achiang@hp.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-04-16sysfs: sysfs poll keep the poll rule of regular file.KOSAKI Motohiro
Currently, following test programs don't finished. % ruby -e ' Thread.new { sleep } File.read("/sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies") ' strace expose the reason. ... open("/sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies", O_RDONLY|O_LARGEFILE) = 3 ioctl(3, SNDCTL_TMR_TIMEBASE or TCGETS, 0xbf9fa6b8) = -1 ENOTTY (Inappropriate ioctl for device) fstat64(3, {st_mode=S_IFREG|0444, st_size=4096, ...}) = 0 _llseek(3, 0, [0], SEEK_CUR) = 0 select(4, [3], NULL, NULL, NULL) = 1 (in [3]) read(3, "1400000 1300000 1200000 1100000 1"..., 4096) = 62 select(4, [3], NULL, NULL, NULL Because Ruby (the scripting language) VM assume select system-call against regular file don't block. it because SUSv3 says "Regular files shall always poll TRUE for reading and writing". see http://www.opengroup.org/onlinepubs/009695399/functions/poll.html it seems valid assumption. But sysfs_poll() don't keep this rule although sysfs file can read and write always. This patch restore proper poll behavior to sysfs. /sys/block/md*/md/sync_action polling application and another sysfs updating sensitive application still can use POLLERR and POLLPRI. Cc: Neil Brown <neilb@suse.de> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-04-16sysfs: don't use global workqueue in sysfs_schedule_callback()Alex Chiang
A sysfs attribute using sysfs_schedule_callback() to commit suicide may end up calling device_unregister(), which will eventually call a driver's ->remove function. Drivers may call flush_scheduled_work() in their shutdown routines, in which case lockdep will complain with something like the following: ============================================= [ INFO: possible recursive locking detected ] 2.6.29-rc8-kk #1 --------------------------------------------- events/4/56 is trying to acquire lock: (events){--..}, at: [<ffffffff80257fc0>] flush_workqueue+0x0/0xa0 but task is already holding lock: (events){--..}, at: [<ffffffff80257648>] run_workqueue+0x108/0x230 other info that might help us debug this: 3 locks held by events/4/56: #0: (events){--..}, at: [<ffffffff80257648>] run_workqueue+0x108/0x230 #1: (&ss->work){--..}, at: [<ffffffff80257648>] run_workqueue+0x108/0x230 #2: (pci_remove_rescan_mutex){--..}, at: [<ffffffff803c10d1>] remove_callback+0x21/0x40 stack backtrace: Pid: 56, comm: events/4 Not tainted 2.6.29-rc8-kk #1 Call Trace: [<ffffffff8026dfcd>] validate_chain+0xb7d/0x1260 [<ffffffff8026eade>] __lock_acquire+0x42e/0xa40 [<ffffffff8026f148>] lock_acquire+0x58/0x80 [<ffffffff80257fc0>] ? flush_workqueue+0x0/0xa0 [<ffffffff8025800d>] flush_workqueue+0x4d/0xa0 [<ffffffff80257fc0>] ? flush_workqueue+0x0/0xa0 [<ffffffff80258070>] flush_scheduled_work+0x10/0x20 [<ffffffffa0144065>] e1000_remove+0x55/0xfe [e1000e] [<ffffffff8033ee30>] ? sysfs_schedule_callback_work+0x0/0x50 [<ffffffff803bfeb2>] pci_device_remove+0x32/0x70 [<ffffffff80441da9>] __device_release_driver+0x59/0x90 [<ffffffff80441edb>] device_release_driver+0x2b/0x40 [<ffffffff804419d6>] bus_remove_device+0xa6/0x120 [<ffffffff8043e46b>] device_del+0x12b/0x190 [<ffffffff8043e4f6>] device_unregister+0x26/0x70 [<ffffffff803ba969>] pci_stop_dev+0x49/0x60 [<ffffffff803baab0>] pci_remove_bus_device+0x40/0xc0 [<ffffffff803c10d9>] remove_callback+0x29/0x40 [<ffffffff8033ee4f>] sysfs_schedule_callback_work+0x1f/0x50 [<ffffffff8025769a>] run_workqueue+0x15a/0x230 [<ffffffff80257648>] ? run_workqueue+0x108/0x230 [<ffffffff8025846f>] worker_thread+0x9f/0x100 [<ffffffff8025bce0>] ? autoremove_wake_function+0x0/0x40 [<ffffffff802583d0>] ? worker_thread+0x0/0x100 [<ffffffff8025b89d>] kthread+0x4d/0x80 [<ffffffff8020d4ba>] child_rip+0xa/0x20 [<ffffffff8020cebc>] ? restore_args+0x0/0x30 [<ffffffff8025b850>] ? kthread+0x0/0x80 [<ffffffff8020d4b0>] ? child_rip+0x0/0x20 Although we know that the device_unregister path will never acquire a lock that a driver might try to acquire in its ->remove, in general we should never attempt to flush a workqueue from within the same workqueue, and lockdep rightly complains. So as long as sysfs attributes cannot commit suicide directly and we are stuck with this callback mechanism, put the sysfs callbacks on their own workqueue instead of the global one. This has the side benefit that if a suicidal sysfs attribute kicks off a long chain of ->remove callbacks, we no longer induce a long delay on the global queue. This also fixes a missing module_put in the error path introduced by sysfs-only-allow-one-scheduled-removal-callback-per-kobj.patch. We never destroy the workqueue, but I'm not sure that's a problem. Reported-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> Tested-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> Signed-off-by: Alex Chiang <achiang@hp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-03-24sysfs: only allow one scheduled removal callback per kobjAlex Chiang
The only way for a sysfs attribute to remove itself (without deadlock) is to use the sysfs_schedule_callback() interface. Vegard Nossum discovered that a poorly written sysfs ->store callback can repeatedly schedule remove callbacks on the same device over and over, e.g. $ while true ; do echo 1 > /sys/devices/.../remove ; done If the 'remove' attribute uses the sysfs_schedule_callback API and also does not protect itself from concurrent accesses, its callback handler will be called multiple times, and will eventually attempt to perform operations on a freed kobject, leading to many problems. Instead of requiring all callers of sysfs_schedule_callback to implement their own synchronization, provide the protection in the infrastructure. Now, sysfs_schedule_callback will only allow one scheduled callback per kobject. On subsequent calls with the same kobject, return -EAGAIN. This is a short term fix. The long term fix is to allow sysfs attributes to remove themselves directly, without any of this callback hokey pokey. [cornelia.huck@de.ibm.com: s390 ccwgroup bits] Reported-by: vegard.nossum@gmail.com Signed-off-by: Alex Chiang <achiang@hp.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-10-16sysfs: Make dir and name args to sysfs_notify() constTrent Piepho
Because they can be, and because code like this produces a warning if they're not: struct device_attribute dev_attr; sysfs_notify(&kobj, NULL, dev_attr.attr.name); Signed-off-by: Trent Piepho <tpiepho@freescale.com> CC: Neil Brown <neilb@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-10-16sysfs: Support sysfs_notify from atomic context with new sysfs_notify_direntNeil Brown
Support sysfs_notify from atomic context with new sysfs_notify_dirent sysfs_notify currently takes sysfs_mutex. This means that it cannot be called in atomic context. sysfs_mutex is sometimes held over a malloc (sysfs_rename_dir) so it can block on low memory. In md I want to be able to notify on a sysfs attribute from atomic context, and I don't want to block on low memory because I could be in the writeout path for freeing memory. So: - export the "sysfs_dirent" structure along with sysfs_get, sysfs_put and sysfs_get_dirent so I can get the sysfs_dirent that I want to notify on and hold it in an md structure. - split sysfs_notify_dirent out of sysfs_notify so the sysfs_dirent can be notified on with no blocking (just a spinlock). Signed-off-by: Neil Brown <neilb@suse.de> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-10-16sysfs: crash debuggingAndrew Morton
Print the name of the last-accessed sysfs file when we oops, to help track down oopses which occur in sysfs store/read handlers. Because these oopses tend to not leave any trace of the offending code in the stack traces. Cc: Kay Sievers <kay.sievers@vrfy.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-07-26Use WARN() in fs/sysfsArjan van de Ven
Use WARN() instead of a printk+WARN_ON() pair; this way the message becomes part of the warning section for better reporting/collection. Also, with this, one fo the if() sections collapses entirely into the WARN(). Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-21sysfs: don't call notify_changeMiklos Szeredi
sysfs_chmod_file() calls notify_change() to change the permission bits on a sysfs file. Replace with explicit call to sysfs_setattr() and fsnotify_change(). This is equivalent, except that security_inode_setattr() is not called. This function is called by drivers, so the security checks do not make any sense. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-04-30fs: replace remaining __FUNCTION__ occurrencesHarvey Harrison
__FUNCTION__ is gcc-specific, use __func__ Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-22[SCSI] sysfs: make group is_valid return a mode_tJames Bottomley
We have a problem in scsi_transport_spi in that we need to customise not only the visibility of the attributes, but also their mode. Fix this by making the is_visible() callback return a mode, with 0 indicating is not visible. Also add a sysfs_update_group() API to allow us to change either the visibility or mode of the files at any time on the fly. Acked-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
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>
2008-04-19SYSFS: Explicitly include required header file slab.h.Robert P. J. Day
After an experimental deletion of the unnecessary inclusion of <linux/slab.h> from the header file <linux/percpu.h>, the following files under fs/sysfs were exposed as needing to explicitly include <linux/slab.h>. Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-03-24driver core: debug for bad dev_attr_show() return value.Andrew Morton
Try to find the culprit who caused http://bugzilla.kernel.org/show_bug.cgi?id=10150 Cc: <balajirrao@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-25Merge git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (200 commits) [SCSI] usbstorage: use last_sector_bug flag universally [SCSI] libsas: abstract STP task status into a function [SCSI] ultrastor: clean up inline asm warnings [SCSI] aic7xxx: fix firmware build [SCSI] aacraid: fib context lock for management ioctls [SCSI] ch: remove forward declarations [SCSI] ch: fix device minor number management bug [SCSI] ch: handle class_device_create failure properly [SCSI] NCR5380: fix section mismatch [SCSI] sg: fix /proc/scsi/sg/devices when no SCSI devices [SCSI] IB/iSER: add logical unit reset support [SCSI] don't use __GFP_DMA for sense buffers if not required [SCSI] use dynamically allocated sense buffer [SCSI] scsi.h: add macro for enclosure bit of inquiry data [SCSI] sd: add fix for devices with last sector access problems [SCSI] fix pcmcia compile problem [SCSI] aacraid: add Voodoo Lite class of cards. [SCSI] aacraid: add new driver features flags [SCSI] qla2xxx: Update version number to 8.02.00-k7. [SCSI] qla2xxx: Issue correct MBC_INITIALIZE_FIRMWARE command. ...
2008-01-24Driver Core: kill subsys_attribute and default sysfs opsKay Sievers
Remove the no longer needed subsys_attributes, they are all converted to the more sensical kobj_attributes. There is no longer a magic fallback in sysfs attribute operations, all kobjects which create simple attributes need explicitely a ktype assigned, which tells the core what was intended here. Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24kobject: remove struct kobj_type from struct ksetGreg Kroah-Hartman
We don't need a "default" ktype for a kset. We should set this explicitly every time for each kset. This change is needed so that we can make ksets dynamic, and cleans up one of the odd, undocumented assumption that the kset/kobject/ktype model has. This patch is based on a lot of help from Kay Sievers. Nasty bug in the block code was found by Dave Young <hidave.darkstar@gmail.com> Cc: Kay Sievers <kay.sievers@vrfy.org> Cc: Dave Young <hidave.darkstar@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24sysfs: remove SPIN_LOCK_UNLOCKEDJiri Slaby
SPIN_LOCK_UNLOCKED is deprecated, use DEFINE_SPINLOCK instead Signed-off-by: Jiri Slaby <jirislaby@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Tejun Heo <teheo@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-23[SCSI] sysfs: fix the sysfs_add_file_to_group interfacesJames Bottomley
I can't see a reason why these shouldn't work on every group. However, they only seem to work on named groups. This patch allows the group functions to work on anonymous groups (those with NULL names). Acked-by: Tejun Heo <htejun@gmail.com> Acked-by: Kay Sievers <kay.sievers@vrfy.org> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2007-11-28sysfs: fix off-by-one error in fill_read_buffer()Miao Xie
I found that there is a off-by-one problem in the following code. Version: 2.6.24-rc2 File: fs/sysfs/file.c:118-122 Function: fill_read_buffer -------------------------------------------------------------------- count = ops->show(kobj, attr_sd->s_attr.attr, buffer->page); sysfs_put_active_two(attr_sd); BUG_ON(count > (ssize_t)PAGE_SIZE); -------------------------------------------------------------------- Because according to the specification of the sysfs and the implement of the show methods, the show methods return the number of bytes which would be generated for the given input, excluding the trailing null.So if the return value of the show methods equals PAGE_SIZE - 1, the buffer is full in fact. And if the return value equals PAGE_SIZE, the resulting string was already truncated,or buffer overflow occurred. This patch fixes an off-by-one error in fill_read_buffer. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Tejun Heo <teheo@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-10-20sysfs: trivial: fix sysfs_create_file kerneldoc spelling mistakeChris Malley
Spelling error in sysfs_create_file kerneldoc. Signed-off-by: Chris Malley <mail@chrismalley.co.uk> Signed-off-by: Adrian Bunk <bunk@kernel.org>
2007-10-12sysfs: add copyrightsTejun Heo
Sysfs has gone through considerable amount of reimplementation. Add copyrights. Any objections? :-) Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-10-12sysfs: move sysfs file poll implementation to sysfs_open_direntTejun Heo
Sysfs file poll implementation is scattered over sysfs and kobject. Event numbering is done in sysfs_dirent but wait itself is done on kobject. This not only unecessarily bloats both kobject and sysfs_dirent but is also buggy - if a sysfs_dirent is removed while there still are pollers, the associaton betwen the kobject and sysfs_dirent breaks and kobject may be freed with the pollers still sleeping on it. This patch moves whole poll implementation into sysfs_open_dirent. Each time a sysfs_open_dirent is created, event number restarts from 1 and pollers sleep on sysfs_open_dirent. As event sequence number is meaningless without any open file and pollers should have open file and thus sysfs_open_dirent, this ephemeral event counting works and is a saner implementation. This patch fixes the dnagling sleepers bug and reduces the sizes of kobject and sysfs_dirent by one pointer. Signed-off-by: Tejun Heo <htejun@gmail.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>