From: "J. Bruce Fields" Subject: [PATCH 6/14] locks: add lock cancel command Date: Sat, 3 Feb 2007 00:34:02 -0500 Message-ID: <49315.8145611689$1170484083@news.gmane.org> References: 11704806552464-git-send-email- <11704808501171-git-send-email-> <11704808502512-git-send-email-> <11704808513862-git-send-email-> <1170480851972-git-send-email-> <11704808513070-git-send-email-> Cc: nfs@lists.sourceforge.net, Marc Eshel To: linux-fsdevel@vger.kernel.org Return-path: In-Reply-To: <11704808513070-git-send-email-> Message-Id: In-Reply-To: References: Sender: linux-fsdevel-owner@vger.kernel.org List-ID: From: Marc Eshel - unquoted 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: "J. Bruce Fields" --- fs/locks.c | 17 +++++++++++++++++ include/linux/fcntl.h | 4 ++++ include/linux/lockd/bind.h | 1 + 3 files changed, 22 insertions(+), 0 deletions(-) diff --git a/fs/locks.c b/fs/locks.c index 819dc28..8ee72b3 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -2061,6 +2061,23 @@ posix_unblock_lock(struct file *filp, struct file_lock *waiter) EXPORT_SYMBOL(posix_unblock_lock); +/** + * vfs_cancel_lock - file byte range unblock lock + * @filp: The file to apply the unblock to + * @fl: The lock to be unblocked + * + * Used by lock managers to cancel blocked requests + */ +int vfs_cancel_lock(struct file *filp, struct file_lock *fl) +{ + if (filp->f_op && filp->f_op->lock) + return filp->f_op->lock(filp, F_CANCELLK, fl); + else + return posix_unblock_lock(filp, fl); +} + +EXPORT_SYMBOL(vfs_cancel_lock); + static void lock_get_status(char* out, struct file_lock *fl, int id, char *pfx) { struct inode *inode = NULL; diff --git a/include/linux/fcntl.h b/include/linux/fcntl.h index 996f561..40b9326 100644 --- a/include/linux/fcntl.h +++ b/include/linux/fcntl.h @@ -3,6 +3,10 @@ #include +/* Cancel a blocking posix lock; internal use only until we expose an + * asynchronous lock api to userspace: */ +#define F_CANCELLK (F_LINUX_SPECIFIC_BASE+5) + #define F_SETLEASE (F_LINUX_SPECIFIC_BASE+0) #define F_GETLEASE (F_LINUX_SPECIFIC_BASE+1) diff --git a/include/linux/lockd/bind.h b/include/linux/lockd/bind.h index 01c25e4..1333dcf 100644 --- a/include/linux/lockd/bind.h +++ b/include/linux/lockd/bind.h @@ -41,5 +41,6 @@ extern void lockd_down(void); extern int vfs_test_lock(struct file *, struct file_lock *, struct file_lock *); extern int vfs_lock_file(struct file *, int cmd, struct file_lock *); extern int vfs_lock_file_conf(struct file *, struct file_lock *, struct file_lock *); +extern int vfs_cancel_lock(struct file *filp, struct file_lock *fl); #endif /* LINUX_LOCKD_BIND_H */ -- 1.5.0.rc1.g72fe