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* [PATCH] fix SMP ordering hole in fcntl_setlk()Al Viro2008-05-061-2/+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>
* [PATCH] split linux/file.hAl Viro2008-05-011-0/+1
| | | | | | Initial splitoff of the low-level stuff; taken to fdtable.h Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Export __locks_copy_lock() so modular lockd buildsRoland Dreier2008-04-251-0/+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>
* locks: don't call ->copy_lock methods on return of conflicting locksJ. Bruce Fields2008-04-251-2/+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>
* leases: remove unneeded variable from fcntl_setlease().David M. Richter2008-04-251-2/+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>
* leases: move lock allocation earlier in generic_setlease()David M. Richter2008-04-251-5/+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>
* leases: when unlocking, skip locking-related stepsDavid M. Richter2008-04-251-11/+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>
* leases: fix a return-value mixupDavid M. Richter2008-04-251-0/+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>
* fs: Remove unnecessary inclusions of asm/semaphore.hMatthew Wilcox2008-04-181-1/+0
| | | | | | | None of these files use any of the functionality promised by asm/semaphore.h. Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
* locks: fix possible infinite loop in fcntl(F_SETLKW) over nfsJ. Bruce Fields2008-04-141-20/+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>
* fs: fix kernel-doc notation warningsRandy Dunlap2008-03-191-2/+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>
* Pidns: make full use of xxx_vnr() callsPavel Emelyanov2008-02-081-3/+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>
* pid-namespaces-vs-locks-interactionVitaliy Gusev2008-02-031-6/+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>
* file locks: Use wait_event_interruptible_timeout()Matthew Wilcox2008-02-031-28/+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>
* locks: clarify posix_locks_deadlockJ. Bruce Fields2008-02-031-30/+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>
* locks: fix possible infinite loop in posix deadlock detectionJ. Bruce Fields2007-10-301-0/+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>
* Slab API: remove useless ctor parameter and reorder parametersChristoph Lameter2007-10-171-1/+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>
* Rework /proc/locks via seq_files and seq_list helpersPavel Emelyanov2007-10-091-71/+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>
* fs/locks.c: use list_for_each_entry() instead of list_for_each()Matthias Kaehlcke2007-10-091-10/+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>
* Cleanup macros for distinguishing mandatory locksPavel Emelyanov2007-10-091-10/+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>
* locks: Fix potential OOPS in generic_setlease()Pavel Emelyanov2007-10-091-9/+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>
* Use list_first_entry in locks_wake_up_blocksPavel Emelyanov2007-10-091-1/+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>
* locks: fix flock_lock_file() commentJ. Bruce Fields2007-10-091-2/+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>
* Memory shortage can result in inconsistent flocks statePavel Emelyanov2007-10-091-4/+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>
* locks: kill redundant local variableJ. Bruce Fields2007-10-091-1/+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>
* locks: reverse order of posix_locks_conflict() argumentsJ. Bruce Fields2007-10-091-1/+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>
* Leases can be hidden by flocksPavel Emelyanov2007-09-111-1/+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>
* rename setlease to generic_setleaseChristoph Hellwig2007-07-311-4/+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>
* mm: Remove slab destructors from kmem_cache_create().Paul Mundt2007-07-201-1/+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>
* locks: fix vfs_test_lock() commentJ. Bruce Fields2007-07-181-2/+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>
* locks: make posix_test_lock() interface more consistentJ. Bruce Fields2007-07-181-6/+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>
* locks: export setlease to filesystemsJ. Bruce Fields2007-07-181-1/+2
| | | | | | | Export setlease so it can used by filesystems to implement their lease methods. Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
* locks: provide a file lease method enabling cluster-coherent leasesJ. Bruce Fields2007-07-181-2/+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>
* locks: rename lease functions to reflect locks.c conventionsJ. Bruce Fields2007-07-181-8/+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>
* locks: share more common lease codeJ. Bruce Fields2007-07-181-20/+10
| | | | | | | | | Share more code between setlease (used by nfsd) and fcntl. Also some minor cleanup. Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu> Acked-by: Christoph Hellwig <hch@infradead.org>
* locks: clean up lease_alloc()J. Bruce Fields2007-07-181-12/+9
| | | | | | | Return the newly allocated structure as the return value instead of using a struct ** parameter. Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
* locks: convert an -EINVAL return to a BUGJ. Bruce Fields2007-07-181-3/+1
| | | | | | | There's no point trying to return an error in these cases, which all represent bugs in the callers. Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
* leases: minor break_lease() comment clarificationdavid m. richter2007-07-181-3/+3
| | | | | | | clarify that break_lease() checks for presence of any lock, not just leases. Signed-off-by: David M. Richter <richterd@citi.umich.edu> Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
* Remove SLAB_CTOR_CONSTRUCTORChristoph Lameter2007-05-171-3/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | SLAB_CTOR_CONSTRUCTOR is always specified. No point in checking it. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: David Howells <dhowells@redhat.com> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Steven French <sfrench@us.ibm.com> Cc: Michael Halcrow <mhalcrow@us.ibm.com> Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Roman Zippel <zippel@linux-m68k.org> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Dave Kleikamp <shaggy@austin.ibm.com> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: Anton Altaparmakov <aia21@cantab.net> Cc: Mark Fasheh <mark.fasheh@oracle.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Jan Kara <jack@ucw.cz> Cc: David Chinner <dgc@sgi.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* locks: fix F_GETLK regression (failure to find conflicts)J. Bruce Fields2007-05-101-2/+3
| | | | | | | | | | | | | | | | | | | | | | In 9d6a8c5c213e34c475e72b245a8eb709258e968c we changed posix_test_lock to modify its single file_lock argument instead of taking separate input and output arguments. This makes it no longer safe to set the output lock's fl_type to F_UNLCK before looking for a conflict, since that means searching for a conflict against a lock with type F_UNLCK. This fixes a regression which causes F_GETLK to incorrectly report no conflict on most filesystems (including any filesystem that doesn't do its own locking). Also fix posix_lock_to_flock() to copy the lock type. This isn't strictly necessary, since the caller already does this; but it seems less likely to cause confusion in the future. Thanks to Doug Chapman for the bug report. Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu> Acked-by: Doug Chapman <doug.chapman@hp.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'server-cluster-locking-api' of git://linux-nfs.org/~bfields/linuxLinus Torvalds2007-05-071-108/+156
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'server-cluster-locking-api' of git://linux-nfs.org/~bfields/linux: gfs2: nfs lock support for gfs2 lockd: add code to handle deferred lock requests lockd: always preallocate block in nlmsvc_lock() lockd: handle test_lock deferrals lockd: pass cookie in nlmsvc_testlock lockd: handle fl_grant callbacks lockd: save lock state on deferral locks: add fl_grant callback for asynchronous lock return nfsd4: Convert NFSv4 to new lock interface locks: add lock cancel command locks: allow {vfs,posix}_lock_file to return conflicting lock locks: factor out generic/filesystem switch from setlock code locks: factor out generic/filesystem switch from test_lock locks: give posix_test_lock same interface as ->lock locks: make ->lock release private data before returning in GETLK case locks: create posix-to-flock helper functions locks: trivial removal of unnecessary parentheses
| * locks: add fl_grant callback for asynchronous lock returnMarc Eshel2007-05-061-0/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Acquiring a lock on a cluster filesystem may require communication with remote hosts, and to avoid blocking lockd or nfsd threads during such communication, we allow the results to be returned asynchronously. When a ->lock() call needs to block, the file system will return -EINPROGRESS, and then later return the results with a call to the routine in the fl_grant field of the lock_manager_operations struct. This differs from the case when ->lock returns -EAGAIN to a blocking lock request; in that case, the filesystem calls fl_notify when the lock is granted, and the caller retries the original lock. So while fl_notify is merely a hint to the caller that it should retry, fl_grant actually communicates the final result of the lock operation (with the lock already acquired in the succesful case). Therefore fl_grant takes a lock, a status and, for the test lock case, a conflicting lock. We also allow fl_grant to return an error to the filesystem, to handle the case where the fl_grant requests arrives after the lock manager has already given up waiting for it. Signed-off-by: Marc Eshel <eshel@almaden.ibm.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
| * locks: add lock cancel commandMarc Eshel2007-05-061-0/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Lock managers need to be able to cancel pending lock requests. In the case where the exported filesystem manages its own locks, it's not sufficient just to call posix_unblock_lock(); we need to let the filesystem know what's happening too. We do this by adding a new fcntl lock command: FL_CANCELLK. Some day this might also be made available to userspace applications that could benefit from an asynchronous locking api. Signed-off-by: Marc Eshel <eshel@almaden.ibm.com> Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
| * locks: allow {vfs,posix}_lock_file to return conflicting lockMarc Eshel2007-05-061-25/+20
| | | | | | | | | | | | | | | | | | | | | | | | The nfsv4 protocol's lock operation, in the case of a conflict, returns information about the conflicting lock. It's unclear how clients can use this, so for now we're not going so far as to add a filesystem method that can return a conflicting lock, but we may as well return something in the local case when it's easy to. Signed-off-by: Marc Eshel <eshel@almaden.ibm.com> Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
| * locks: factor out generic/filesystem switch from setlock codeMarc Eshel2007-05-061-32/+36
| | | | | | | | | | | | | | | | | | | | | | Factor out the code that switches between generic and filesystem-specific lock methods; eventually we want to call this from lock managers (lockd and nfsd) too; currently they only call the generic methods. This patch does that for all the setlk code. Signed-off-by: Marc Eshel <eshel@almaden.ibm.com> Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
| * locks: factor out generic/filesystem switch from test_lockJ. Bruce Fields2007-05-061-13/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Factor out the code that switches between generic and filesystem-specific lock methods; eventually we want to call this from lock managers (lockd and nfsd) too; currently they only call the generic methods. This patch does that for test_lock. Note that this hasn't been necessary until recently, because the few filesystems that define ->lock() (nfs, cifs...) aren't exportable via NFS. However GFS (and, in the future, other cluster filesystems) need to implement their own locking to get cluster-coherent locking, and also want to be able to export locking to NFS (lockd and NFSv4). So we accomplish this by factoring out code such as this and exporting it for the use of lockd and nfsd. Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
| * locks: give posix_test_lock same interface as ->lockMarc Eshel2007-05-061-21/+16
| | | | | | | | | | | | | | | | | | posix_test_lock() and ->lock() do the same job but have gratuitously different interfaces. Modify posix_test_lock() so the two agree, simplifying some code in the process. Signed-off-by: Marc Eshel <eshel@almaden.ibm.com> Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
| * locks: make ->lock release private data before returning in GETLK caseJ. Bruce Fields2007-05-061-4/+0
| | | | | | | | | | | | | | | | | | | | | | | | The file_lock argument to ->lock is used to return the conflicting lock when found. There's no reason for the filesystem to return any private information with this conflicting lock, but nfsv4 is. Fix nfsv4 client, and modify locks.c to stop calling fl_release_private for it in this case. Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu> Cc: "Trond Myklebust" <Trond.Myklebust@netapp.com>"
| * locks: create posix-to-flock helper functionsJ. Bruce Fields2007-04-161-25/+36
| | | | | | | | | | | | | | | | Factor out a bit of messy code by creating posix-to-flock counterparts to the existing flock-to-posix helper functions. Cc: Christoph Hellwig <hch@infradead.org> Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
| * locks: trivial removal of unnecessary parenthesesJ. Bruce Fields2007-04-161-2/+2
| | | | | | | | | | | | Remove some unnecessary parentheses. Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
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