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2010-09-20sysfs: checking for NULL instead of ERR_PTRDan Carpenter
commit 57f9bdac2510cd7fda58e4a111d250861eb1ebeb upstream. d_path() returns an ERR_PTR and it doesn't return NULL. Signed-off-by: Dan Carpenter <error27@gmail.com> Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-02-23sysfs: sysfs_sd_setattr set iattrs unconditionallyEric W. Biederman
commit 7c0ff870d1ed287504a61ed865f3d728c757436b upstream. There is currently a bug in sysfs_sd_setattr inherited from sysfs_setattr in 2.6.32 where the first time we set the attributes on a sysfs file we allocate backing store but do not set the backing store attributes. Resulting in overly restrictive permissions on sysfs files. The fix is to simply modify the code so that it always executes when we update the sysfs attributes, as we did in 2.6.31 and earlier. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Tested-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-11-05sysfs: Don't leak secdata when a sysfs_dirent is freed.Eric W. Biederman
While refreshing my sysfs patches I noticed a leak in the secdata implementation. We don't free the secdata when we free the sysfs dirent. This is a bug in 2.6.32-rc5 that we really should close. Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
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>
2009-10-14sysfs: Allow sysfs_move_dir(..., NULL) again.Cornelia Huck
As device_move() and kobject_move() both handle a NULL destination, sysfs_move_dir() should do this as well (again) and fall back to sysfs_root in that case. Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Cc: Phil Carmody <ext-phil.2.carmody@nokia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-27const: mark struct vm_struct_operationsAlexey Dobriyan
* mark struct vm_area_struct::vm_ops as const * mark vm_ops in AGP code But leave TTM code alone, something is fishy there with global vm_ops being used. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-11Merge branch 'writeback' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds
* 'writeback' of git://git.kernel.dk/linux-2.6-block: writeback: check for registered bdi in flusher add and inode dirty writeback: add name to backing_dev_info writeback: add some debug inode list counters to bdi stats writeback: get rid of pdflush completely writeback: switch to per-bdi threads for flushing data writeback: move dirty inodes from super_block to backing_dev_info writeback: get rid of generic_sync_sb_inodes() export
2009-09-11writeback: add name to backing_dev_infoJens Axboe
This enables us to track who does what and print info. Its main use is catching dirty inodes on the default_backing_dev_info, so we can fix that up. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-09-10sysfs: Add labeling support for sysfsDavid P. Quigley
This patch adds a setxattr handler to the file, directory, and symlink inode_operations structures for sysfs. The patch uses hooks introduced in the previous patch to handle the getting and setting of security information for the sysfs inodes. As was suggested by Eric Biederman the struct iattr in the sysfs_dirent structure has been replaced by a structure which contains the iattr, secdata and secdata length to allow the changes to persist in the event that the inode representing the sysfs_dirent is evicted. Because sysfs only stores this information when a change is made all the optional data is moved into one dynamically allocated field. This patch addresses an issue where SELinux was denying virtd access to the PCI configuration entries in sysfs. The lack of setxattr handlers for sysfs required that a single label be assigned to all entries in sysfs. Granting virtd access to every entry in sysfs is not an acceptable solution so fine grained labeling of sysfs is required such that individual entries can be labeled appropriately. [sds: Fixed compile-time warnings, coding style, and setting of inode security init flags.] Signed-off-by: David P. Quigley <dpquigl@tycho.nsa.gov> Signed-off-by: Stephen D. Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <jmorris@namei.org>
2009-07-28sysfs: fix hardlink count on device_movePeter Oberparleiter
Update directory hardlink count when moving kobjects to a new parent. Fixes the following problem which occurs when several devices are moved to the same parent and then unregistered: > ls -laF /sys/devices/css0/defunct/ > total 0 > drwxr-xr-x 4294967295 root root 0 2009-07-14 17:02 ./ > drwxr-xr-x 114 root root 0 2009-07-14 17:02 ../ > drwxr-xr-x 2 root root 0 2009-07-14 17:01 power/ > -rw-r--r-- 1 root root 4096 2009-07-14 17:01 uevent Signed-off-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-07-08Free the memory allocated by memdup_user() in fs/sysfs/bin.cCatalin Marinas
Commit 1c8542c7bb replaced kmalloc() with memdup_user() in the write() function but also dropped the kfree(temp). The memdup_user() function allocates memory which is never freed. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Parag Warudkar <parag.warudkar@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-15Sysfs: fix possible memleak in sysfs_follow_linkArmin Kuster
There is the possiblity of a memory leak if a page is allocated and if sysfs_getlink() fails in the sysfs_follow_link. Signed-off-by: Armin Kuster <akuster@mvista.com> 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>
2009-04-20sysfs: use memdup_user()Li Zefan
Remove open-coded memdup_user(). Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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>
2009-04-01mm: page_mkwrite change prototype to match fault: fix sysfsHugh Dickins
Fix warnings and return values in sysfs bin_page_mkwrite(), fixing fs/sysfs/bin.c: In function `bin_page_mkwrite': fs/sysfs/bin.c:250: warning: passing argument 2 of `bb->vm_ops->page_mkwrite' from incompatible pointer type fs/sysfs/bin.c: At top level: fs/sysfs/bin.c:280: warning: initialization from incompatible pointer type Expects to have my [PATCH next] sysfs: fix some bin_vm_ops errors Signed-off-by: Hugh Dickins <hugh@veritas.com> Cc: Nick Piggin <npiggin@suse.de> Cc: "Eric W. Biederman" <ebiederm@aristanetworks.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-27Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (37 commits) fs: avoid I_NEW inodes Merge code for single and multiple-instance mounts Remove get_init_pts_sb() Move common mknod_ptmx() calls into caller Parse mount options just once and copy them to super block Unroll essentials of do_remount_sb() into devpts vfs: simple_set_mnt() should return void fs: move bdev code out of buffer.c constify dentry_operations: rest constify dentry_operations: configfs constify dentry_operations: sysfs constify dentry_operations: JFS constify dentry_operations: OCFS2 constify dentry_operations: GFS2 constify dentry_operations: FAT constify dentry_operations: FUSE constify dentry_operations: procfs constify dentry_operations: ecryptfs constify dentry_operations: CIFS constify dentry_operations: AFS ...
2009-03-27constify dentry_operations: sysfsAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-03-24sysfs: fix some bin_vm_ops errorsHugh Dickins
Commit 86c9508eb1c0ce5aa07b5cf1d36b60c54efc3d7a "sysfs: don't block indefinitely for unmapped files" in linux-next crashes the PowerMac G5 when X starts up. It's caught out by the way powerpc's pci_mmap of legacy_mem uses shmem_zero_setup(), substituting a new vma->vm_file whose private_data no longer points to the bin_buffer (substitution done because some versions of X crash if that mmap fails). The fix to this is straightforward: the original vm_file is fput() in that case, so this mmap won't block sysfs at all, so just don't switch over to bin_vm_ops if vm_file has changed. But more fixes made before realizing that was the problem:- It should not be an error if bin_page_mkwrite() finds no underlying page_mkwrite(). Check that a file already mmap'ed has the same underlying vm_ops _before_ pointing vma->vm_ops at bin_vm_ops. If the file being mmap'ed is a shmem/tmpfs file, don't fail the mmap on CONFIG_NUMA=y, just because that has a set_policy and get_policy: provide bin_set_policy, bin_get_policy and bin_migrate. Signed-off-by: Hugh Dickins <hugh@veritas.com> Acked-by: Eric Biederman <ebiederm@aristanetworks.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>
2009-03-24sysfs: don't block indefinitely for unmapped files.Eric W. Biederman
Modify sysfs bin files so that we can remove the bin file while they are still mapped. When the kobject is removed we unmap the bin file and arrange for future accesses to the mapping to receive SIGBUS. Implementing this prevents a nasty DOS when pci devices are hot plugged and unplugged. Where if any of their resources were mmaped the kernel could not free up their pci resources or release their pci data structures. [akpm@linux-foundation.org: remove unused var] Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> Cc: Jesse Barnes <jbarnes@virtuousgeek.org> Acked-by: Tejun Heo <tj@kernel.org> Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-03-24sysfs: reference sysfs_dirent from sysfs inodesEric W. Biederman
The sysfs_dirent serves as both an inode and a directory entry for sysfs. To prevent the sysfs inode numbers from being freed prematurely hold a reference to sysfs_dirent from the sysfs inode. [akpm@linux-foundation.org: add comment] Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> Cc: Tejun Heo <tj@kernel.org> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-03-24sysfs: sysfs_add_one WARNs with full path to duplicate filenameAlex Chiang
sysfs: sysfs_add_one WARNs with full path to duplicate filename As a debugging aid, it can be useful to know the full path to a duplicate file being created in sysfs. We now will display warnings such as: sysfs: cannot create duplicate filename '/foo' when attempting to create multiple files named 'foo' in the sysfs root, or: sysfs: cannot create duplicate filename '/bus/pci/slots/5/foo' when attempting to create multiple files named 'foo' under a given directory in sysfs. The path displayed is always a relative path to sysfs_root. The leading '/' in the path name refers to the sysfs_root mount point, and should not be confused with the "real" '/'. Thanks to Alex Williamson for essentially writing sysfs_pathname. Cc: Alex Williamson <alex.williamson@hp.com> Signed-off-by: Alex Chiang <achiang@hp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-03-24sysfs: Take sysfs_mutex when fetching the root inode.Eric W. Biederman
sysfs_get_inode ultimately calls sysfs_count_nlink when the a directory inode is fectched. sysfs_count_nlink needs to be called under the sysfs_mutex to guard against the unlikely but possible scenario that the root directory is changing as we are counting the number entries in it, and just in general to be consistent. Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-03-24SYSFS: use standard magic.h for sysfsQinghuang Feng
SYSFS_MAGIC has been added into magic.h, so only use that definition in magic.h to avoid potential consistency problem. Signed-off-by: Qinghuang Feng <qhfeng.kernel@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-01-26Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6: klist.c: bit 0 in pointer can't be used as flag debugfs: introduce stub for debugfs_create_size_t() when DEBUG_FS=n sysfs: fix problems with binary files PNP: fix broken pnp lowercasing for acpi module aliases driver core: Convert '/' to '!' in dev_set_name()
2009-01-22fs/Kconfig: move sysfs outAlexey Dobriyan
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
2009-01-20sysfs: fix problems with binary filesGreg Kroah-Hartman
Some sysfs binary files don't like having 0 passed to them as a size. Fix this up at the root by just returning to the vfs if userspace asks us for a zero sized buffer. Thanks to Pavel Roskin for pointing this out. Reported-by: Pavel Roskin <proski@gnu.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-01-05zero i_uid/i_gid on inode allocationAl Viro
... and don't bother in callers. Don't bother with zeroing i_blocks, while we are at it - it's already been zeroed. i_mode is not worth the effort; it has no common default value. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-10-23[PATCH] fix ->llseek for more directoriesChristoph Hellwig
With this patch all directory fops instances that have a readdir that doesn't take the BKL are switched to generic_file_llseek. Signed-off-by: Christoph Hellwig <hch@lst.de>
2008-10-16kobject: Cleanup kobject_rename and !CONFIG_SYSFSEric W. Biederman
It finally dawned on me what the clean fix to sysfs_rename_dir calling kobject_set_name is. Move the work into kobject_rename where it belongs. The callers serialize us anyway so this is safe. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: Tejun Heo <tj@kernel.org> 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: use ilookup5() instead of ilookup5_nowait()Tejun Heo
As inode creation is protected by sysfs_mutex, ilookup5_nowait() always either fails to find at all or finds one which is fully initialized, so using ilookup5_nowait() or ilookup5() doesn't make any difference. Switch to ilookup5() as it's planned to be removed. This change also makes lookup return value handling a bit simpler. This change was suggested by Al Viro. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Al Viro <viro@hera.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-10-16sysfs: fix deadlockNick Piggin
On Thu, Sep 11, 2008 at 10:27:10AM +0200, Ingo Molnar wrote: > and it's working fine on most boxes. One testbox found this new locking > scenario: > > PM: Adding info for No Bus:vcsa7 > EDAC DEBUG: MC0: i82860_check() > > ======================================================= > [ INFO: possible circular locking dependency detected ] > 2.6.27-rc6-tip #1 > ------------------------------------------------------- > X/4873 is trying to acquire lock: > (&bb->mutex){--..}, at: [<c020ba20>] mmap+0x40/0xa0 > > but task is already holding lock: > (&mm->mmap_sem){----}, at: [<c0125a1e>] sys_mmap2+0x8e/0xc0 > > which lock already depends on the new lock. > > > the existing dependency chain (in reverse order) is: > > -> #1 (&mm->mmap_sem){----}: > [<c017dc96>] validate_chain+0xa96/0xf50 > [<c017ef2b>] __lock_acquire+0x2cb/0x5b0 > [<c017f299>] lock_acquire+0x89/0xc0 > [<c01aa8fb>] might_fault+0x6b/0x90 > [<c040b618>] copy_to_user+0x38/0x60 > [<c020bcfb>] read+0xfb/0x170 > [<c01c09a5>] vfs_read+0x95/0x110 > [<c01c1443>] sys_pread64+0x63/0x80 > [<c012146f>] sysenter_do_call+0x12/0x43 > [<ffffffff>] 0xffffffff > > -> #0 (&bb->mutex){--..}: > [<c017d8b7>] validate_chain+0x6b7/0xf50 > [<c017ef2b>] __lock_acquire+0x2cb/0x5b0 > [<c017f299>] lock_acquire+0x89/0xc0 > [<c0d6f2ab>] __mutex_lock_common+0xab/0x3c0 > [<c0d6f698>] mutex_lock_nested+0x38/0x50 > [<c020ba20>] mmap+0x40/0xa0 > [<c01b111e>] mmap_region+0x14e/0x450 > [<c01b170f>] do_mmap_pgoff+0x2ef/0x310 > [<c0125a3d>] sys_mmap2+0xad/0xc0 > [<c012146f>] sysenter_do_call+0x12/0x43 > [<ffffffff>] 0xffffffff > > other info that might help us debug this: > > 1 lock held by X/4873: > #0: (&mm->mmap_sem){----}, at: [<c0125a1e>] sys_mmap2+0x8e/0xc0 > > stack backtrace: > Pid: 4873, comm: X Not tainted 2.6.27-rc6-tip #1 > [<c017cd09>] print_circular_bug_tail+0x79/0xc0 > [<c017d8b7>] validate_chain+0x6b7/0xf50 > [<c017a5b5>] ? trace_hardirqs_off_caller+0x15/0xb0 > [<c017ef2b>] __lock_acquire+0x2cb/0x5b0 > [<c017f299>] lock_acquire+0x89/0xc0 > [<c020ba20>] ? mmap+0x40/0xa0 > [<c0d6f2ab>] __mutex_lock_common+0xab/0x3c0 > [<c020ba20>] ? mmap+0x40/0xa0 > [<c0d6f698>] mutex_lock_nested+0x38/0x50 > [<c020ba20>] ? mmap+0x40/0xa0 > [<c020ba20>] mmap+0x40/0xa0 > [<c01b111e>] mmap_region+0x14e/0x450 > [<c01afb88>] ? arch_get_unmapped_area_topdown+0xf8/0x160 > [<c01b170f>] do_mmap_pgoff+0x2ef/0x310 > [<c0125a3d>] sys_mmap2+0xad/0xc0 > [<c012146f>] sysenter_do_call+0x12/0x43 > [<c0120000>] ? __switch_to+0x130/0x220 > ======================= > evbug.c: Event. Dev: input3, Type: 20, Code: 0, Value: 500 > warning: `sudo' uses deprecated v2 capabilities in a way that may be insecure. > > i've attached the config. > > at first sight it looks like a genuine bug in fs/sysfs/bin.c? Yes, it is a real bug by the looks. bin.c takes bb->mutex under mmap_sem when it is mmapped, and then does its copy_*_user under bb->mutex too. Here is a basic fix for the sysfs lor. From: Nick Piggin <npiggin@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> 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>
2008-07-21driver core: Suppress sysfs warnings for device_rename().Cornelia Huck
driver core: Suppress sysfs warnings for device_rename(). Renaming network devices to an already existing name is not something we want sysfs to print a scary warning for, since the callers can deal with this correctly. So let's introduce sysfs_create_link_nowarn() which gets rid of the common warning. Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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>
2008-05-14sysfs: remove error messages for -EEXIST caseStephen Hemminger
It is possible that the entry in sysfs already exists, one case of this is when a network device is renamed to bonding_masters. Anyway, in this case the proper error path is for device_rename to return an error code, not to generate bogus backtrace and errors. Also, to avoid possible races, the create link should be done before the remove link. This makes a device rename atomic operation like other renames. Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-30sysfs: Disallow truncation of files in sysfsBen Hutchings
sysfs allows attribute files to be truncated, e.g. using ftruncate(), with the expected effect on their inode. For most attributes, this doesn't change the "real" size of the file i.e. how much can be read from it. However, the parameter validation for reading and writing binary attribute files is based on the inode size and not the size specified in the file's bin_attribute, so it can be broken by this. For example, if we try using dd to write to such a file: # pwd /sys/bus/pci/devices/0000:08:00.0 # ls -l config -rw-r--r-- 1 root root 4096 Feb 1 17:35 config # dd if=/dev/zero of=config bs=4 count=1 1+0 records in 1+0 records out # ls -l config -rw-r--r-- 1 root root 0 Feb 1 17:50 config # dd if=/dev/zero of=config bs=4 count=1 seek=128 dd: writing `config': No space left on device 1+0 records in 0+0 records out Also, after truncation to 0, parameter validation for read and write is disabled. Most bin_attribute read and write methods also validate the size and offset, but for some this will allow out-of-range access. This may be a security issue, though access to such files is often limited to root. In any case, the validation should remain for safety's sake!) This was previously reported in Bugzilla as bug 9867. sysfs should ignore size changes or else refuse them (by returning -EINVAL). This patch makes it ignore them. Signed-off-by: Ben Hutchings <bhutchings@solarflare.com> 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>
2008-04-30mm: bdi: add separate writeback accounting capabilityMiklos Szeredi
Add a new BDI capability flag: BDI_CAP_NO_ACCT_WB. If this flag is set, then don't update the per-bdi writeback stats from test_set_page_writeback() and test_clear_page_writeback(). Misc cleanups: - convert bdi_cap_writeback_dirty() and friends to static inline functions - create a flag that includes all three dirty/writeback related flags, since almst all users will want to have them toghether Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> 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>
2008-04-18sysfs: Allow removal of symlinks in the sysfs rootMark Fasheh
Allow callers of sysfs_remove_link() to pass a NULL kobj, in which case sysfs_root will be used as the parent directory. This allows us to tear down top level symlinks created via sysfs_create_link(), which already has similar handling of a NULL parent object. Signed-off-by: Mark Fasheh <mfasheh@suse.com> Acked-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>
2008-02-07sysfs: remove BUG_ON() from sysfs_remove_group()Greg Kroah-Hartman
It's possible that the caller of sysfs_remove_group messed up and passed in an attribute group that was not really registered to this kobject. But don't panic for such a foolish error, spit out a warning about what happened, and continue on our way safely. Cc: Roland Dreier <rdreier@cisco.com> Cc: Tejun Heo <htejun@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>