path: root/fs/locks.c
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2009-09-22const: make lock_manager_operations constAlexey Dobriyan1-1/+1
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-11Merge branch 'sched-core-for-linus' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (64 commits) sched: Fix sched::sched_stat_wait tracepoint field sched: Disable NEW_FAIR_SLEEPERS for now sched: Keep kthreads at default priority sched: Re-tune the scheduler latency defaults to decrease worst-case latencies sched: Turn off child_runs_first sched: Ensure that a child can't gain time over it's parent after fork() sched: enable SD_WAKE_IDLE sched: Deal with low-load in wake_affine() sched: Remove short cut from select_task_rq_fair() sched: Turn on SD_BALANCE_NEWIDLE sched: Clean up topology.h sched: Fix dynamic power-balancing crash sched: Remove reciprocal for cpu_power sched: Try to deal with low capacity, fix update_sd_power_savings_stats() sched: Try to deal with low capacity sched: Scale down cpu_power due to RT tasks sched: Implement dynamic cpu_power sched: Add smt_gain sched: Update the cpu_power sum during load-balance sched: Add SD_PREFER_SIBLING ...
2009-07-18sched: Convert the only user of cond_resched_bkl to use cond_resched()Frederic Weisbecker1-1/+1
fs/locks.c:flock_lock_file() is the only user of cond_resched_bkl() This helper doesn't do anything more than cond_resched(). The latter naming is enough to explain that we are rescheduling if needed. The bkl suffix suggests another semantics but it's actually a synonym of cond_resched(). Reported-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1247725694-6082-7-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-17security: fix security_file_lock cmd argumentSten Spans1-1/+1
Pass posix-translated lock operations to security_file_lock when invoked via sys_flock. Signed-off-by: Sten Spans <Sten_Spans@genua.de> Signed-off-by: James Morris <jmorris@namei.org>
2009-04-24lockd: call locks_release_private to cleanup per-filesystem stateFelix Blyakher1-1/+2
For every lock request lockd creates a new file_lock object in nlmsvc_setgrantargs() by copying the passed in file_lock with locks_copy_lock(). A filesystem can attach it's own lock_operations vector to the file_lock. It has to be cleaned up at the end of the file_lock's life. However, lockd doesn't do it today, yet it asserts in nlmclnt_release_lockargs() that the per-filesystem state is clean. This patch fixes it by exporting locks_release_private() and adding it to nlmsvc_freegrantargs(), to be symmetrical to creating a file_lock in nlmsvc_setgrantargs(). Signed-off-by: Felix Blyakher <felixb@sgi.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-01-14[CVE-2009-0029] System call wrappers part 16Heiko Carstens1-1/+1
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2008-11-14CRED: Wrap task credential accesses in the filesystem subsystemDavid Howells1-1/+1
Wrap access to task credentials so that they can be separated more easily from the task_struct during the introduction of COW creds. Change most current->(|e|s|fs)[ug]id to current_(|e|s|fs)[ug]id(). Change some task->e?[ug]id to task_e?[ug]id(). In some places it makes more sense to use RCU directly rather than a convenient wrapper; these will be addressed by later patches. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: James Morris <jmorris@namei.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: James Morris <jmorris@namei.org>
2008-10-23Merge branch 'proc' of ↵Linus Torvalds1-1/+21
git://git.kernel.org/pub/scm/linux/kernel/git/adobriyan/proc * 'proc' of git://git.kernel.org/pub/scm/linux/kernel/git/adobriyan/proc: (35 commits) proc: remove fs/proc/proc_misc.c proc: move /proc/vmcore creation to fs/proc/vmcore.c proc: move pagecount stuff to fs/proc/page.c proc: move all /proc/kcore stuff to fs/proc/kcore.c proc: move /proc/schedstat boilerplate to kernel/sched_stats.h proc: move /proc/modules boilerplate to kernel/module.c proc: move /proc/diskstats boilerplate to block/genhd.c proc: move /proc/zoneinfo boilerplate to mm/vmstat.c proc: move /proc/vmstat boilerplate to mm/vmstat.c proc: move /proc/pagetypeinfo boilerplate to mm/vmstat.c proc: move /proc/buddyinfo boilerplate to mm/vmstat.c proc: move /proc/vmallocinfo to mm/vmalloc.c proc: move /proc/slabinfo boilerplate to mm/slub.c, mm/slab.c proc: move /proc/slab_allocators boilerplate to mm/slab.c proc: move /proc/interrupts boilerplate code to fs/proc/interrupts.c proc: move /proc/stat to fs/proc/stat.c proc: move rest of /proc/partitions code to block/genhd.c proc: move /proc/cpuinfo code to fs/proc/cpuinfo.c proc: move /proc/devices code to fs/proc/devices.c proc: move rest of /proc/locks to fs/locks.c ...
2008-10-23proc: move rest of /proc/locks to fs/locks.cAlexey Dobriyan1-1/+21
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
2008-10-21[PATCH] introduce fmode_t, do annotationsAl Viro1-1/+2
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-07-26SL*B: drop kmem cache argument from constructorAlexey Dobriyan1-1/+1
Kmem cache passed to constructor is only needed for constructors that are themselves multiplexeres. Nobody uses this "feature", nor does anybody uses passed kmem cache in non-trivial way, so pass only pointer to object. Non-trivial places are: arch/powerpc/mm/init_64.c arch/powerpc/mm/hugetlbpage.c This is flag day, yes. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Acked-by: Christoph Lameter <cl@linux-foundation.org> Cc: Jon Tollefson <kniht@linux.vnet.ibm.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Matt Mackall <mpm@selenic.com> [akpm@linux-foundation.org: fix arch/powerpc/mm/hugetlbpage.c] [akpm@linux-foundation.org: fix mm/slab.c] [akpm@linux-foundation.org: fix ubifs] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25locks: allow ->lock() to return FILE_LOCK_DEFERREDMiklos Szeredi1-14/+9
Allow filesystem's ->lock() method to call posix_lock_file() instead of posix_lock_file_wait(), and return FILE_LOCK_DEFERRED. This makes it possible to implement a such a ->lock() function, that works with the lock manager, which needs the call to be asynchronous. Now the vfs_lock_file() helper can be used, so this is a cleanup as well. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: Matthew Wilcox <matthew@wil.cx> Cc: David Teigland <teigland@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25locks: cleanup code duplicationMiklos Szeredi1-40/+31
Extract common code into a function. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: Matthew Wilcox <matthew@wil.cx> Cc: David Teigland <teigland@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25locks: add special return value for asynchronous locksMiklos Szeredi1-14/+14
Use a special error value FILE_LOCK_DEFERRED to mean that a locking operation returned asynchronously. This is returned by posix_lock_file() for sleeping locks to mean that the lock has been queued on the block list, and will be woken up when it might become available and needs to be retried (either fl_lmops->fl_notify() is called or fl_wait is woken up). f_op->lock() to mean either the above, or that the filesystem will call back with fl_lmops->fl_grant() when the result of the locking operation is known. The filesystem can do this for sleeping as well as non-sleeping locks. This is to make sure, that return values of -EAGAIN and -EINPROGRESS by filesystems are not mistaken to mean an asynchronous locking. This also makes error handling in fs/locks.c and lockd/svclock.c slightly cleaner. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: Matthew Wilcox <matthew@wil.cx> Cc: David Teigland <teigland@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-23[patch 4/4] flock: remove unused fields from file_lock_operationsDenis V. Lunev1-6/+0
fl_insert and fl_remove are not used right now in the kernel. Remove them. Signed-off-by: Denis V. Lunev <den@openvz.org> Cc: Matthew Wilcox <matthew@wil.cx> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: "J. Bruce Fields" <bfields@fieldses.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-05-11Add new 'cond_resched_bkl()' helper functionLinus Torvalds1-1/+1
It acts exactly like a regular 'cond_resched()', but will not get optimized away when CONFIG_PREEMPT is set. Normal kernel code is already preemptable in the presense of CONFIG_PREEMPT, so cond_resched() is optimized away (see commit 02b67cc3ba36bdba351d6c3a00593f4ec550d9d3 "sched: do not do cond_resched() when CONFIG_PREEMPT"). But when wanting to conditionally reschedule while holding a lock, you need to use "cond_sched_lock(lock)", and the new function is the BKL equivalent of that. Also make fs/locks.c use it. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-06[PATCH] fix SMP ordering hole in fcntl_setlk()Al Viro1-2/+15
fcntl_setlk()/close() race prevention has a subtle hole - we need to make sure that if we *do* have an fcntl/close race on SMP box, the access to descriptor table and inode->i_flock won't get reordered. As it is, we get STORE inode->i_flock, LOAD descriptor table entry vs. STORE descriptor table entry, LOAD inode->i_flock with not a single lock in common on both sides. We do have BKL around the first STORE, but check in locks_remove_posix() is outside of BKL and for a good reason - we don't want BKL on common path of close(2). Solution is to hold ->file_lock around fcheck() in there; that orders us wrt removal from descriptor table that preceded locks_remove_posix() on close path and we either come first (in which case eviction will be handled by the close side) or we'll see the effect of close and do eviction ourselves. Note that even though it's read-only access, we do need ->file_lock here - rcu_read_lock() won't be enough to order the things. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-05-01[PATCH] split linux/file.hAl Viro1-0/+1
Initial splitoff of the low-level stuff; taken to fdtable.h Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-04-25Export __locks_copy_lock() so modular lockd buildsRoland Dreier1-0/+1
Commit 1a747ee0 ("locks: don't call ->copy_lock methods on return of conflicting locks") changed fs/lockd/svclock.c to call __locks_copy_lock() instead of locks_copy_lock(), but lockd can be built as a module and __locks_copy_lock() is not exported, which causes a build error ERROR: "__locks_copy_lock" [fs/lockd/lockd.ko] undefined! with CONFIG_LOCKD=m. Fix this by exporting __locks_copy_lock(). Signed-off-by: Roland Dreier <rolandd@cisco.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-25locks: don't call ->copy_lock methods on return of conflicting locksJ. Bruce Fields1-2/+2
The file_lock structure is used both as a heavy-weight representation of an active lock, with pointers to reference-counted structures, etc., and as a simple container for parameters that describe a file lock. The conflicting lock returned from __posix_lock_file is an example of the latter; so don't call the filesystem or lock manager callbacks when copying to it. This also saves the need for an unnecessary locks_init_lock in the nfsv4 server. Thanks to Trond for pointing out the error. Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu> Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-04-25leases: remove unneeded variable from fcntl_setlease().David M. Richter1-2/+1
fcntl_setlease() has a struct dentry* that is used only once; this patch removes it. Signed-off-by: David M. Richter <richterd@citi.umich.edu> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2008-04-25leases: move lock allocation earlier in generic_setlease()David M. Richter1-5/+5
In generic_setlease(), the struct file_lock is allocated after tests for the presence of conflicting readers/writers is done, despite the fact that the allocation might block; this patch moves the allocation earlier. A subsequent set of patches will rely on this behavior to properly serialize between a modified __break_lease() and generic_setlease(). Signed-off-by: David M. Richter <richterd@citi.umich.edu> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2008-04-25leases: when unlocking, skip locking-related stepsDavid M. Richter1-11/+13
In generic_setlease(), we don't need to allocate a new struct file_lock or check for readers or writers when called with F_UNLCK. Signed-off-by: David M. Richter <richterd@citi.umich.edu> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2008-04-25leases: fix a return-value mixupDavid M. Richter1-0/+1
Fixes a return-value mixup from 85c59580b30c82aa771aa33b37217a6b6851bc14 "locks: Fix potential OOPS in generic_setlease()", in which -ENOMEM replaced what had been intended to stay -EAGAIN in the variable "error". Signed-off-by: David M. Richter <richterd@citi.umich.edu> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2008-04-18fs: Remove unnecessary inclusions of asm/semaphore.hMatthew Wilcox1-1/+0
None of these files use any of the functionality promised by asm/semaphore.h. Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
2008-04-14locks: fix possible infinite loop in fcntl(F_SETLKW) over nfsJ. Bruce Fields1-20/+28
Miklos Szeredi found the bug: "Basically what happens is that on the server nlm_fopen() calls nfsd_open() which returns -EACCES, to which nlm_fopen() returns NLM_LCK_DENIED. "On the client this will turn into a -EAGAIN (nlm_stat_to_errno()), which in will cause fcntl_setlk() to retry forever." So, for example, opening a file on an nfs filesystem, changing permissions to forbid further access, then trying to lock the file, could result in an infinite loop. And Trond Myklebust identified the culprit, from Marc Eshel and I: 7723ec9777d9832849b76475b1a21a2872a40d20 "locks: factor out generic/filesystem switch from setlock code" That commit claimed to just be reshuffling code, but actually introduced a behavioral change by calling the lock method repeatedly as long as it returned -EAGAIN. We assumed this would be safe, since we assumed a lock of type SETLKW would only return with either success or an error other than -EAGAIN. However, nfs does can in fact return -EAGAIN in this situation, and independently of whether that behavior is correct or not, we don't actually need this change, and it seems far safer not to depend on such assumptions about the filesystem's ->lock method. Therefore, revert the problematic part of the original commit. This leaves vfs_lock_file() and its other callers unchanged, while returning fcntl_setlk and fcntl_setlk64 to their former behavior. Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu> Tested-by: Miklos Szeredi <mszeredi@suse.cz> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: Marc Eshel <eshel@almaden.ibm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-19fs: fix kernel-doc notation warningsRandy Dunlap1-2/+2
Fix kernel-doc notation warnings in fs/. Warning(mmotm-2008-0314-1449//fs/super.c:560): missing initial short description on line: * mark_files_ro Warning(mmotm-2008-0314-1449//fs/locks.c:1277): missing initial short description on line: * lease_get_mtime Warning(mmotm-2008-0314-1449//fs/locks.c:1277): missing initial short description on line: * lease_get_mtime Warning(mmotm-2008-0314-1449//fs/namei.c:1368): missing initial short description on line: * lookup_one_len: filesystem helper to lookup single pathname component Warning(mmotm-2008-0314-1449//fs/buffer.c:3221): missing initial short description on line: * bh_uptodate_or_lock: Test whether the buffer is uptodate Warning(mmotm-2008-0314-1449//fs/buffer.c:3240): missing initial short description on line: * bh_submit_read: Submit a locked buffer for reading Warning(mmotm-2008-0314-1449//fs/fs-writeback.c:30): missing initial short description on line: * writeback_acquire: attempt to get exclusive writeback access to a device Warning(mmotm-2008-0314-1449//fs/fs-writeback.c:47): missing initial short description on line: * writeback_in_progress: determine whether there is writeback in progress Warning(mmotm-2008-0314-1449//fs/fs-writeback.c:58): missing initial short description on line: * writeback_release: relinquish exclusive writeback access against a device. Warning(mmotm-2008-0314-1449//include/linux/jbd.h:351): contents before sections Warning(mmotm-2008-0314-1449//include/linux/jbd.h:561): contents before sections Warning(mmotm-2008-0314-1449//fs/jbd/transaction.c:1935): missing initial short description on line: * void journal_invalidatepage() Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08Pidns: make full use of xxx_vnr() callsPavel Emelyanov1-3/+2
Some time ago the xxx_vnr() calls (e.g. pid_vnr or find_task_by_vpid) were _all_ converted to operate on the current pid namespace. After this each call like xxx_nr_ns(foo, current->nsproxy->pid_ns) is nothing but a xxx_vnr(foo) one. Switch all the xxx_nr_ns() callers to use the xxx_vnr() calls where appropriate. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Reviewed-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-03pid-namespaces-vs-locks-interactionVitaliy Gusev1-6/+23
fcntl(F_GETLK,..) can return pid of process for not current pid namespace (if process is belonged to the several namespaces). It is true also for pids in /proc/locks. So correct behavior is saving pointer to the struct pid of the process lock owner. Signed-off-by: Vitaliy Gusev <vgusev@openvz.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2008-02-03file locks: Use wait_event_interruptible_timeout()Matthew Wilcox1-28/+4
interruptible_sleep_on_locked() is just an open-coded wait_event_interruptible_timeout(), with the one difference that interruptible_sleep_on_locked() doesn't bother to check the condition on which it is waiting, depending instead on the BKL to avoid the case where it blocks after the wakeup has already been called. locks_block_on_timeout() is only used in one place, so it's actually simpler to inline it into its caller. Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2008-02-03locks: clarify posix_locks_deadlockJ. Bruce Fields1-30/+40
For such a short function (with such a long comment), posix_locks_deadlock() seems to cause a lot of confusion. Attempt to make it a bit clearer: - Remove the initial posix_same_owner() check, which can never pass (since this is only called in the case that block_fl and caller_fl conflict) - Use an explicit loop (and a helper function) instead of a goto. - Rewrite the comment, attempting a clearer explanation, and removing some uninteresting historical detail. Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2007-10-30locks: fix possible infinite loop in posix deadlock detectionJ. Bruce Fields1-0/+11
It's currently possible to send posix_locks_deadlock() into an infinite loop (under the BKL). For now, fix this just by bailing out after a few iterations. We may want to fix this in a way that better clarifies the semantics of deadlock detection. But that will take more time, and this minimal fix is probably adequate for any realistic scenario, and is simple enough to be appropriate for applying to stable kernels now. Thanks to George Davis for reporting the problem. Cc: "George G. Davis" <gdavis@mvista.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu> Acked-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-17Slab API: remove useless ctor parameter and reorder parametersChristoph Lameter1-1/+1
Slab constructors currently have a flags parameter that is never used. And the order of the arguments is opposite to other slab functions. The object pointer is placed before the kmem_cache pointer. Convert ctor(void *object, struct kmem_cache *s, unsigned long flags) to ctor(struct kmem_cache *s, void *object) throughout the kernel [akpm@linux-foundation.org: coupla fixes] Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-09Rework /proc/locks via seq_files and seq_list helpersPavel Emelyanov1-71/+51
Currently /proc/locks is shown with a proc_read function, but its behavior is rather complex as it has to manually handle current offset and buffer length. On the other hand, files that show objects from lists can be easily reimplemented using the sequential files and the seq_list_XXX() helpers. This saves (as usually) 16 lines of code and more than 200 from the .text section. [akpm@linux-foundation.org: no externs in C] [akpm@linux-foundation.org: warning fixes] Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2007-10-09fs/locks.c: use list_for_each_entry() instead of list_for_each()Matthias Kaehlcke1-10/+7
fs/locks.c: use list_for_each_entry() instead of list_for_each() in posix_locks_deadlock() and get_locks_status() Signed-off-by: Matthias Kaehlcke <matthias.kaehlcke@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2007-10-09Cleanup macros for distinguishing mandatory locksPavel Emelyanov1-10/+4
The combination of S_ISGID bit set and S_IXGRP bit unset is used to mark the inode as "mandatory lockable" and there's a macro for this check called MANDATORY_LOCK(inode). However, fs/locks.c and some filesystems still perform the explicit i_mode checking. Besides, Andrew pointed out, that this macro is buggy itself, as it dereferences the inode arg twice. Convert this macro into static inline function and switch its users to it, making the code shorter and more readable. The __mandatory_lock() helper is to be used in places where the IS_MANDLOCK() for superblock is already known to be true. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: David Howells <dhowells@redhat.com> Cc: Eric Van Hensbergen <ericvh@gmail.com> Cc: Ron Minnich <rminnich@sandia.gov> Cc: Latchesar Ionkov <lucho@ionkov.net> Cc: Steven Whitehouse <swhiteho@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2007-10-09locks: Fix potential OOPS in generic_setlease()Pavel Emelyanov1-9/+12
This code is run under lock_kernel(), which is dropped during sleeping operations, so the following race is possible: CPU1: CPU2: vfs_setlease(); vfs_setlease(); lock_kernel(); lock_kernel(); /* spin */ generic_setlease(): ... for (before = ...) /* here we found some lease after * which we will insert the new one */ fl = locks_alloc_lock(); /* go to sleep in this allocation and * drop the BKL */ generic_setlease(): ... for (before = ...) /* here we find the "before" pointing * at the one we found on CPU1 */ ->fl_change(my_before, arg); lease_modify(); locks_free_lock(); /* and we freed it */ ... unlock_kernel(); locks_insert_lock(before, fl); /* OOPS! We have just tried to add the lease * at the tail of already removed one */ The similar races are already handled in other code - all the allocations are performed before any checks/updates. Thanks to Kamalesh Babulal for testing and for a bug report on an earlier version. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu> Cc: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
2007-10-09Use list_first_entry in locks_wake_up_blocksPavel Emelyanov1-1/+3
This routine deletes all the elements from the list with the "while (!list_empty())" loop, and we already have a list_first_entry() macro to help it look nicer :) Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
2007-10-09locks: fix flock_lock_file() commentJ. Bruce Fields1-2/+1
This comment wasn't updated when lease support was added, and it makes essentially the same mistake that the code made before a recent bugfix. Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2007-10-09Memory shortage can result in inconsistent flocks statePavel Emelyanov1-4/+9
When the flock_lock_file() is called to change the flock from F_RDLCK to F_WRLCK or vice versa the existing flock can be removed without appropriate warning. Look: for_each_lock(inode, before) { struct file_lock *fl = *before; if (IS_POSIX(fl)) break; if (IS_LEASE(fl)) continue; if (filp != fl->fl_file) continue; if (request->fl_type == fl->fl_type) goto out; found = 1; locks_delete_lock(before); <<<<<< ! break; } if after this point the subsequent locks_alloc_lock() will fail the return code will be -ENOMEM, but the existing lock is already removed. This is a known feature that such "re-locking" is not atomic, but in the racy case the file should stay locked (although by some other process), but in this case the file will be unlocked. The proposal is to prepare the lock in advance keeping no chance to fail in the future code. Found during making the flocks pid-namespaces aware. (Note: Thanks to Reuben Farrelly for finding a bug in an earlier version of this patch.) Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu> Cc: Reuben Farrelly <reuben-linuxkernel@reub.net>
2007-10-09locks: kill redundant local variableJ. Bruce Fields1-1/+1
There's no need for another variable local to this loop; we can use the variable (of the same name!) already declared at the top of the function, and not used till later (at which point it's initialized, so this is safe). Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2007-10-09locks: reverse order of posix_locks_conflict() argumentsJ. Bruce Fields1-1/+1
The first argument to posix_locks_conflict() is meant to be a lock request, and the second a lock from an inode's lock request. It doesn't really make a difference which order you call them in, since the only asymmetric test in posix_lock_conflict() is the check whether the second argument is a posix lock--and every caller already does that check for some reason. But may as well fix posix_test_lock() to call posix_locks_conflict() with the arguments in the same order as everywhere else. Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
2007-09-11Leases can be hidden by flocksPavel Emelyanov1-1/+1
The inode->i_flock list contains the leases, flocks and posix locks in the specified order. However, the flocks are added in the head of this list thus hiding the leases from F_GETLEASE command, from time_out_leases() and other code that expects the leases to come first. The following example will demonstrate this: #define _GNU_SOURCE #include <unistd.h> #include <fcntl.h> #include <stdio.h> #include <sys/file.h> static void show_lease(int fd) { int res; res = fcntl(fd, F_GETLEASE); switch (res) { case F_RDLCK: printf("Read lease\n"); break; case F_WRLCK: printf("Write lease\n"); break; case F_UNLCK: printf("No leases\n"); break; default: printf("Some shit\n"); break; } } int main(int argc, char **argv) { int fd, res; fd = open(argv[1], O_RDONLY); if (fd == -1) { perror("Can't open file"); return 1; } res = fcntl(fd, F_SETLEASE, F_WRLCK); if (res == -1) { perror("Can't set lease"); return 1; } show_lease(fd); if (flock(fd, LOCK_SH) == -1) { perror("Can't flock shared"); return 1; } show_lease(fd); return 0; } The first call to show_lease() will show the write lease set, but the second will show no leases. Fix the flock adding so that the leases always stay in the head of this list. Found during making the flocks pid-namespaces aware. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Acked-by: "J. Bruce Fields" <bfields@fieldses.org> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-31rename setlease to generic_setleaseChristoph Hellwig1-4/+4
Make it a little more clear that this is the default implementation for the setleast operation. Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Steven Whitehouse <swhiteho@redhat.com> Acked-by: "J. Bruce Fields" <bfields@fieldses.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-20mm: Remove slab destructors from kmem_cache_create().Paul Mundt1-1/+1
Slab destructors were no longer supported after Christoph's c59def9f222d44bb7e2f0a559f2906191a0862d7 change. They've been BUGs for both slab and slub, and slob never supported them either. This rips out support for the dtor pointer from kmem_cache_create() completely and fixes up every single callsite in the kernel (there were about 224, not including the slab allocator definitions themselves, or the documentation references). Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2007-07-18locks: fix vfs_test_lock() commentJ. Bruce Fields1-2/+1
Thanks to Doug Chapman for pointing out that the comment here is inconsistent with the function prototype. Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
2007-07-18locks: make posix_test_lock() interface more consistentJ. Bruce Fields1-6/+4
Since posix_test_lock(), like fcntl() and ->lock(), indicates absence or presence of a conflict lock by setting fl_type to, respectively, F_UNLCK or something other than F_UNLCK, the return value is no longer needed. Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
2007-07-18locks: export setlease to filesystemsJ. Bruce Fields1-1/+2
Export setlease so it can used by filesystems to implement their lease methods. Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
2007-07-18locks: provide a file lease method enabling cluster-coherent leasesJ. Bruce Fields1-2/+22
Currently leases are only kept locally, so there's no way for a distributed filesystem to enforce them against multiple clients. We're particularly interested in the case of nfsd exporting a cluster filesystem, in which case nfsd needs cluster-coherent leases in order to implement delegations correctly. Also add some documentation. Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2007-07-18locks: rename lease functions to reflect locks.c conventionsJ. Bruce Fields1-8/+7
We've been using the convention that vfs_foo is the function that calls a filesystem-specific foo method if it exists, or falls back on a generic method if it doesn't; thus vfs_foo is what is called when some other part of the kernel (normally lockd or nfsd) wants to get a lock, whereas foo is what filesystems call to use the underlying local functionality as part of their lock implementation. So rename setlease to vfs_setlease (which will call a filesystem-specific setlease after a later patch) and __setlease to setlease. Also, vfs_setlease need only be GPL-exported as long as it's only needed by lockd and nfsd. Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>

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