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Commit f475ae95 authored by Trond Myklebust's avatar Trond Myklebust
Browse files

VFS: Allow caller to determine if BSD or posix locks were actually freed 



Change posix_lock_file_conf(), and flock_lock_file() so that if called
with an F_UNLCK argument, and the FL_EXISTS flag they will indicate
whether or not any locks were actually freed by returning 0 or -ENOENT.

Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent 5e66dd6d

fs/locks.c

+16 −2
Original line number Diff line number Diff line
@@ -725,6 +725,10 @@ next_task: 
/* Try to create a FLOCK lock on filp. We always insert new FLOCK locks

 * at the head of the list, but that's secret knowledge known only to

 * flock_lock_file and posix_lock_file.

 *

 * Note that if called with an FL_EXISTS argument, the caller may determine

 * whether or not a lock was successfully freed by testing the return

 * value for -ENOENT.

 */

static int flock_lock_file(struct file *filp, struct file_lock *request)

{
@@ -750,8 +754,11 @@ static int flock_lock_file(struct file *filp, struct file_lock *request) 
		break;

	}



	if (request->fl_type == F_UNLCK)

	if (request->fl_type == F_UNLCK) {

		if ((request->fl_flags & FL_EXISTS) && !found)

			error = -ENOENT;

		goto out;

	}



	error = -ENOMEM;

	new_fl = locks_alloc_lock();
@@ -948,8 +955,11 @@ static int __posix_lock_file_conf(struct inode *inode, struct file_lock *request 


	error = 0;

	if (!added) {

		if (request->fl_type == F_UNLCK)

		if (request->fl_type == F_UNLCK) {

			if (request->fl_flags & FL_EXISTS)

				error = -ENOENT;

			goto out;

		}



		if (!new_fl) {

			error = -ENOLCK;
@@ -996,6 +1006,10 @@ static int __posix_lock_file_conf(struct inode *inode, struct file_lock *request 
 * Add a POSIX style lock to a file.

 * We merge adjacent & overlapping locks whenever possible.

 * POSIX locks are sorted by owner task, then by starting address

 *

 * Note that if called with an FL_EXISTS argument, the caller may determine

 * whether or not a lock was successfully freed by testing the return

 * value for -ENOENT.

 */

int posix_lock_file(struct file *filp, struct file_lock *fl)

{

include/linux/fs.h

+1 −0
Original line number Diff line number Diff line
@@ -716,6 +716,7 @@ extern spinlock_t files_lock; 
#define FL_POSIX	1

#define FL_FLOCK	2

#define FL_ACCESS	8	/* not trying to lock, just looking */

#define FL_EXISTS	16	/* when unlocking, test for existence */

#define FL_LEASE	32	/* lease held on this file */

#define FL_CLOSE	64	/* unlock on close */

#define FL_SLEEP	128	/* A blocking lock */