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authorMarc Eshel <eshel@almaden.ibm.com>2007-01-18 17:52:58 -0500
committerJ. Bruce Fields <bfields@citi.umich.edu>2007-05-06 20:38:28 -0400
commit9b9d2ab4154a42ea4a119f7d3e4e0288bfe0bb79 (patch)
tree62af6b2eff0885c26aa2af4b01890cc02cf0b2f0
parent150b393456e5a23513cace286a019e87151e47f0 (diff)
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locks: add lock cancel command
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>
-rw-r--r--fs/locks.c16
-rw-r--r--include/linux/fcntl.h4
-rw-r--r--include/linux/fs.h1
3 files changed, 21 insertions, 0 deletions
diff --git a/fs/locks.c b/fs/locks.c
index ee46584..242328e 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -2028,6 +2028,22 @@ 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);
+ return 0;
+}
+
+EXPORT_SYMBOL_GPL(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 <asm/fcntl.h>
+/* 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/fs.h b/include/linux/fs.h
index c92d0bd..64b8ae2 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -857,6 +857,7 @@ extern int posix_lock_file_wait(struct file *, struct file_lock *);
extern int posix_unblock_lock(struct file *, struct file_lock *);
extern int vfs_test_lock(struct file *, struct file_lock *);
extern int vfs_lock_file(struct file *, unsigned int, struct file_lock *, struct file_lock *);
+extern int vfs_cancel_lock(struct file *filp, struct file_lock *fl);
extern int flock_lock_file_wait(struct file *filp, struct file_lock *fl);
extern int __break_lease(struct inode *inode, unsigned int flags);
extern void lease_get_mtime(struct inode *, struct timespec *time);
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