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path: root/fs/afs/flock.c
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2016-09-04fs/afs/flock: Remove deprecated create_singlethread_workqueueBhaktipriya Shridhar
The workqueue "afs_lock_manager" queues work item &vnode->lock_work, per vnode. Since there can be multiple vnodes and since their work items can be executed concurrently, alloc_workqueue has been used to replace the deprecated create_singlethread_workqueue instance. The WQ_MEM_RECLAIM flag has been set to ensure forward progress under memory pressure because the workqueue is being used on a memory reclaim path. Since there are fixed number of work items, explicit concurrency limit is unnecessary here. Signed-off-by: Bhaktipriya Shridhar <bhaktipriya96@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com>
2016-01-22wrappers for ->i_mutex accessAl Viro
parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested}, inode_foo(inode) being mutex_foo(&inode->i_mutex). Please, use those for access to ->i_mutex; over the coming cycle ->i_mutex will become rwsem, with ->lookup() done with it held only shared. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-06-02locks: ensure that fl_owner is always initialized properly in flock and ↵Jeff Layton
lease codepaths Currently, the fl_owner isn't set for flock locks. Some filesystems use byte-range locks to simulate flock locks and there is a common idiom in those that does: fl->fl_owner = (fl_owner_t)filp; fl->fl_start = 0; fl->fl_end = OFFSET_MAX; Since flock locks are generally "owned" by the open file description, move this into the common flock lock setup code. The fl_start and fl_end fields are already set appropriately, so remove the unneeded setting of that in flock ops in those filesystems as well. Finally, the lease code also sets the fl_owner as if they were owned by the process and not the open file description. This is incorrect as leases have the same ownership semantics as flock locks. Set them the same way. The lease code doesn't actually use the fl_owner value for anything, so this is more for consistency's sake than a bugfix. Reported-by: Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by: Jeff Layton <jlayton@poochiereds.net> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> (Staging portion) Acked-by: J. Bruce Fields <bfields@fieldses.org>
2013-06-29locks: protect most of the file_lock handling with i_lockJeff Layton
Having a global lock that protects all of this code is a clear scalability problem. Instead of doing that, move most of the code to be protected by the i_lock instead. The exceptions are the global lists that the ->fl_link sits on, and the ->fl_block list. ->fl_link is what connects these structures to the global lists, so we must ensure that we hold those locks when iterating over or updating these lists. Furthermore, sound deadlock detection requires that we hold the blocked_list state steady while checking for loops. We also must ensure that the search and update to the list are atomic. For the checking and insertion side of the blocked_list, push the acquisition of the global lock into __posix_lock_file and ensure that checking and update of the blocked_list is done without dropping the lock in between. On the removal side, when waking up blocked lock waiters, take the global lock before walking the blocked list and dequeue the waiters from the global list prior to removal from the fl_block list. With this, deadlock detection should be race free while we minimize excessive file_lock_lock thrashing. Finally, in order to avoid a lock inversion problem when handling /proc/locks output we must ensure that manipulations of the fl_block list are also protected by the file_lock_lock. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-22new helper: file_inode(file)Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-05fs/locks.c: prepare for BKL removalArnd Bergmann
This prepares the removal of the big kernel lock from the file locking code. We still use the BKL as long as fs/lockd uses it and ceph might sleep, but we can flip the definition to a private spinlock as soon as that's done. All users outside of fs/lockd get converted to use lock_flocks() instead of lock_kernel() where appropriate. Based on an earlier patch to use a spinlock from Matthew Wilcox, who has attempted this a few times before, the earliest patch from over 10 years ago turned it into a semaphore, which ended up being slower than the BKL and was subsequently reverted. Someone should do some serious performance testing when this becomes a spinlock, since this has caused problems before. Using a spinlock should be at least as good as the BKL in theory, but who knows... Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Matthew Wilcox <willy@linux.intel.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Miklos Szeredi <mszeredi@suse.cz> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: John Kacur <jkacur@redhat.com> Cc: Sage Weil <sage@newdream.net> Cc: linux-kernel@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org
2009-09-22const: make file_lock_operations constAlexey Dobriyan
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>
2009-06-30AFS: Fix lock imbalanceJiri Slaby
Don't unlock on vfs_rejected_lock path in afs_do_setlk, since the lock is unlocked after abort_attempt label. Signed-off-by: Jiri Slaby <jirislaby@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-09AFS: clean up explicit check for mandatory locksPavel Emelyanov
The __mandatory_lock(inode) macro makes the same check, but makes the code more readable. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2007-07-31AFS: fix file lockingDavid Howells
Fix file locking for AFS: (*) Start the lock manager thread under a mutex to avoid a race. (*) Made the locking non-fair: New readlocks will jump pending writelocks if there's a readlock currently granted on a file. This makes the behaviour similar to Linux's VFS locking. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19afs build fixAndrew Morton
Bruce and David's patches clashed. fs/afs/flock.c: In function 'afs_do_getlk': fs/afs/flock.c:459: error: void value not ignored as it ought to be Cc: "J. Bruce Fields" <bfields@fieldses.org> Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16AFS: implement file lockingDavid Howells
Implement file locking for AFS. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>