- 26 4月, 2008 5 次提交
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由 J. Bruce Fields 提交于
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: NJ. Bruce Fields <bfields@citi.umich.edu> Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
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由 David M. Richter 提交于
fcntl_setlease() has a struct dentry* that is used only once; this patch removes it. Signed-off-by: NDavid M. Richter <richterd@citi.umich.edu> Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
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由 David M. Richter 提交于
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: NDavid M. Richter <richterd@citi.umich.edu> Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
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由 David M. Richter 提交于
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: NDavid M. Richter <richterd@citi.umich.edu> Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
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由 David M. Richter 提交于
Fixes a return-value mixup from 85c59580 "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: NDavid M. Richter <richterd@citi.umich.edu> Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
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- 19 4月, 2008 1 次提交
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由 Matthew Wilcox 提交于
None of these files use any of the functionality promised by asm/semaphore.h. Signed-off-by: NMatthew Wilcox <willy@linux.intel.com>
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- 15 4月, 2008 1 次提交
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由 J. Bruce Fields 提交于
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: 7723ec97 "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: NJ. Bruce Fields <bfields@citi.umich.edu> Tested-by: NMiklos Szeredi <mszeredi@suse.cz> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: Marc Eshel <eshel@almaden.ibm.com> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 20 3月, 2008 1 次提交
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由 Randy Dunlap 提交于
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: NRandy Dunlap <randy.dunlap@oracle.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 09 2月, 2008 1 次提交
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由 Pavel Emelyanov 提交于
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: NPavel Emelyanov <xemul@openvz.org> Reviewed-by: NOleg Nesterov <oleg@tv-sign.ru> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 04 2月, 2008 3 次提交
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由 Vitaliy Gusev 提交于
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: NVitaliy Gusev <vgusev@openvz.org> Acked-by: NSerge Hallyn <serue@us.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
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由 Matthew Wilcox 提交于
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: NMatthew Wilcox <willy@linux.intel.com> Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
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由 J. Bruce Fields 提交于
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: NJ. Bruce Fields <bfields@citi.umich.edu>
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- 31 10月, 2007 1 次提交
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由 J. Bruce Fields 提交于
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: NJ. Bruce Fields <bfields@citi.umich.edu> Acked-by: NAlan Cox <alan@redhat.com> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 17 10月, 2007 1 次提交
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由 Christoph Lameter 提交于
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: NChristoph Lameter <clameter@sgi.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 10 10月, 2007 9 次提交
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由 Pavel Emelyanov 提交于
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: NPavel Emelyanov <xemul@openvz.org> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
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由 Matthias Kaehlcke 提交于
fs/locks.c: use list_for_each_entry() instead of list_for_each() in posix_locks_deadlock() and get_locks_status() Signed-off-by: NMatthias Kaehlcke <matthias.kaehlcke@gmail.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
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由 Pavel Emelyanov 提交于
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: NPavel 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: NAndrew Morton <akpm@linux-foundation.org>
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由 Pavel Emelyanov 提交于
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: NPavel Emelyanov <xemul@openvz.org> Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu> Cc: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
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由 Pavel Emelyanov 提交于
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: NPavel Emelyanov <xemul@openvz.org>
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由 J. Bruce Fields 提交于
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: NJ. Bruce Fields <bfields@citi.umich.edu>
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由 Pavel Emelyanov 提交于
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: NPavel Emelyanov <xemul@openvz.org> Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu> Cc: Reuben Farrelly <reuben-linuxkernel@reub.net>
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由 J. Bruce Fields 提交于
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: NJ. Bruce Fields <bfields@citi.umich.edu>
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由 J. Bruce Fields 提交于
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: N"J. Bruce Fields" <bfields@citi.umich.edu>
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- 12 9月, 2007 1 次提交
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由 Pavel Emelyanov 提交于
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: NPavel Emelyanov <xemul@openvz.org> Acked-by: N"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: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 01 8月, 2007 1 次提交
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由 Christoph Hellwig 提交于
Make it a little more clear that this is the default implementation for the setleast operation. Signed-off-by: NChristoph Hellwig <hch@lst.de> Cc: Steven Whitehouse <swhiteho@redhat.com> Acked-by: N"J. Bruce Fields" <bfields@fieldses.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 20 7月, 2007 1 次提交
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由 Paul Mundt 提交于
Slab destructors were no longer supported after Christoph's c59def9f 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: NPaul Mundt <lethal@linux-sh.org>
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- 19 7月, 2007 9 次提交
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由 J. Bruce Fields 提交于
Thanks to Doug Chapman for pointing out that the comment here is inconsistent with the function prototype. Signed-off-by: N"J. Bruce Fields" <bfields@citi.umich.edu>
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由 J. Bruce Fields 提交于
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: N"J. Bruce Fields" <bfields@citi.umich.edu>
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由 J. Bruce Fields 提交于
Export setlease so it can used by filesystems to implement their lease methods. Signed-off-by: N"J. Bruce Fields" <bfields@citi.umich.edu>
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由 J. Bruce Fields 提交于
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: NJ. Bruce Fields <bfields@citi.umich.edu>
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由 J. Bruce Fields 提交于
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: N"J. Bruce Fields" <bfields@citi.umich.edu>
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由 J. Bruce Fields 提交于
Share more code between setlease (used by nfsd) and fcntl. Also some minor cleanup. Signed-off-by: N"J. Bruce Fields" <bfields@citi.umich.edu> Acked-by: NChristoph Hellwig <hch@infradead.org>
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由 J. Bruce Fields 提交于
Return the newly allocated structure as the return value instead of using a struct ** parameter. Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
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由 J. Bruce Fields 提交于
There's no point trying to return an error in these cases, which all represent bugs in the callers. Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
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由 david m. richter 提交于
clarify that break_lease() checks for presence of any lock, not just leases. Signed-off-by: NDavid M. Richter <richterd@citi.umich.edu> Signed-off-by: N"J. Bruce Fields" <bfields@citi.umich.edu>
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- 17 5月, 2007 1 次提交
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由 Christoph Lameter 提交于
SLAB_CTOR_CONSTRUCTOR is always specified. No point in checking it. Signed-off-by: NChristoph 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: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 11 5月, 2007 1 次提交
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由 J. Bruce Fields 提交于
In 9d6a8c5c 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: N"J. Bruce Fields" <bfields@citi.umich.edu> Acked-by: NDoug Chapman <doug.chapman@hp.com> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 08 5月, 2007 1 次提交
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由 Christoph Lameter 提交于
I have never seen a use of SLAB_DEBUG_INITIAL. It is only supported by SLAB. I think its purpose was to have a callback after an object has been freed to verify that the state is the constructor state again? The callback is performed before each freeing of an object. I would think that it is much easier to check the object state manually before the free. That also places the check near the code object manipulation of the object. Also the SLAB_DEBUG_INITIAL callback is only performed if the kernel was compiled with SLAB debugging on. If there would be code in a constructor handling SLAB_DEBUG_INITIAL then it would have to be conditional on SLAB_DEBUG otherwise it would just be dead code. But there is no such code in the kernel. I think SLUB_DEBUG_INITIAL is too problematic to make real use of, difficult to understand and there are easier ways to accomplish the same effect (i.e. add debug code before kfree). There is a related flag SLAB_CTOR_VERIFY that is frequently checked to be clear in fs inode caches. Remove the pointless checks (they would even be pointless without removeal of SLAB_DEBUG_INITIAL) from the fs constructors. This is the last slab flag that SLUB did not support. Remove the check for unimplemented flags from SLUB. Signed-off-by: NChristoph Lameter <clameter@sgi.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 07 5月, 2007 2 次提交
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由 Marc Eshel 提交于
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: NMarc Eshel <eshel@almaden.ibm.com> Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
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由 Marc Eshel 提交于
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: NMarc Eshel <eshel@almaden.ibm.com> Signed-off-by: N"J. Bruce Fields" <bfields@citi.umich.edu>
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