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Commit 150b3934 authored by Marc Eshel's avatar Marc Eshel Committed by J. Bruce Fields
Browse files

locks: allow {vfs,posix}_lock_file to return conflicting lock 



The nfsv4 protocol's lock operation, in the case of a conflict, returns
information about the conflicting lock.

It's unclear how clients can use this, so for now we're not going so far as to
add a filesystem method that can return a conflicting lock, but we may as well
return something in the local case when it's easy to.

Signed-off-by: default avatarMarc Eshel <eshel@almaden.ibm.com>
Signed-off-by: default avatar"J. Bruce Fields" <bfields@citi.umich.edu>
parent 7723ec97

fs/lockd/svclock.c

+3 −3
Original line number Original line Diff line number Diff line
@@ -363,7 +363,7 @@ again: 
	} else

	} else

		lock = &block->b_call->a_args.lock;

		lock = &block->b_call->a_args.lock;





	error = posix_lock_file(file->f_file, &lock->fl);

	error = posix_lock_file(file->f_file, &lock->fl, NULL);

	lock->fl.fl_flags &= ~FL_SLEEP;

	lock->fl.fl_flags &= ~FL_SLEEP;





	dprintk("lockd: posix_lock_file returned %d\n", error);

	dprintk("lockd: posix_lock_file returned %d\n", error);
@@ -467,7 +467,7 @@ nlmsvc_unlock(struct nlm_file *file, struct nlm_lock *lock) 
	nlmsvc_cancel_blocked(file, lock);

	nlmsvc_cancel_blocked(file, lock);





	lock->fl.fl_type = F_UNLCK;

	lock->fl.fl_type = F_UNLCK;

	error = posix_lock_file(file->f_file, &lock->fl);

	error = posix_lock_file(file->f_file, &lock->fl, NULL);





	return (error < 0)? nlm_lck_denied_nolocks : nlm_granted;

	return (error < 0)? nlm_lck_denied_nolocks : nlm_granted;

}

}
@@ -569,7 +569,7 @@ nlmsvc_grant_blocked(struct nlm_block *block) 




	/* Try the lock operation again */

	/* Try the lock operation again */

	lock->fl.fl_flags |= FL_SLEEP;

	lock->fl.fl_flags |= FL_SLEEP;

	error = posix_lock_file(file->f_file, &lock->fl);

	error = posix_lock_file(file->f_file, &lock->fl, NULL);

	lock->fl.fl_flags &= ~FL_SLEEP;

	lock->fl.fl_flags &= ~FL_SLEEP;





	switch (error) {

	switch (error) {

fs/lockd/svcsubs.c

+1 −1
Original line number Original line Diff line number Diff line
@@ -182,7 +182,7 @@ again: 
			lock.fl_type  = F_UNLCK;

			lock.fl_type  = F_UNLCK;

			lock.fl_start = 0;

			lock.fl_start = 0;

			lock.fl_end   = OFFSET_MAX;

			lock.fl_end   = OFFSET_MAX;

			if (posix_lock_file(file->f_file, &lock) < 0) {

			if (posix_lock_file(file->f_file, &lock, NULL) < 0) {

				printk("lockd: unlock failure in %s:%d\n",

				printk("lockd: unlock failure in %s:%d\n",

						__FILE__, __LINE__);

						__FILE__, __LINE__);

				return 1;

				return 1;

fs/locks.c

+20 −25
Original line number Original line Diff line number Diff line
@@ -801,7 +801,7 @@ out: 
	return error;

	return error;

}

}





static int __posix_lock_file_conf(struct inode *inode, struct file_lock *request, struct file_lock *conflock)

static int __posix_lock_file(struct inode *inode, struct file_lock *request, struct file_lock *conflock)

{

{

	struct file_lock *fl;

	struct file_lock *fl;

	struct file_lock *new_fl = NULL;

	struct file_lock *new_fl = NULL;
@@ -1007,6 +1007,7 @@ static int __posix_lock_file_conf(struct inode *inode, struct file_lock *request 
 * posix_lock_file - Apply a POSIX-style lock to a file

 * posix_lock_file - Apply a POSIX-style lock to a file

 * @filp: The file to apply the lock to

 * @filp: The file to apply the lock to

 * @fl: The lock to be applied

 * @fl: The lock to be applied

 * @conflock: Place to return a copy of the conflicting lock, if found.

 *

 *

 * Add a POSIX style lock to a file.

 * Add a POSIX style lock to a file.

 * We merge adjacent & overlapping locks whenever possible.

 * We merge adjacent & overlapping locks whenever possible.
@@ -1016,26 +1017,12 @@ static int __posix_lock_file_conf(struct inode *inode, struct file_lock *request 
 * whether or not a lock was successfully freed by testing the return

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

 * value for -ENOENT.

 * value for -ENOENT.

 */

 */

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

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

{

	return __posix_lock_file_conf(filp->f_path.dentry->d_inode, fl, NULL);

}

EXPORT_SYMBOL(posix_lock_file);



/**

 * posix_lock_file_conf - Apply a POSIX-style lock to a file

 * @filp: The file to apply the lock to

 * @fl: The lock to be applied

 * @conflock: Place to return a copy of the conflicting lock, if found.

 *

 * Except for the conflock parameter, acts just like posix_lock_file.

 */

int posix_lock_file_conf(struct file *filp, struct file_lock *fl,

			struct file_lock *conflock)

			struct file_lock *conflock)

{

{

	return __posix_lock_file_conf(filp->f_path.dentry->d_inode, fl, conflock);

	return __posix_lock_file(filp->f_path.dentry->d_inode, fl, conflock);

}

}

EXPORT_SYMBOL(posix_lock_file_conf);

EXPORT_SYMBOL(posix_lock_file);





/**

/**

 * posix_lock_file_wait - Apply a POSIX-style lock to a file

 * posix_lock_file_wait - Apply a POSIX-style lock to a file
@@ -1051,7 +1038,7 @@ int posix_lock_file_wait(struct file *filp, struct file_lock *fl) 
	int error;

	int error;

	might_sleep ();

	might_sleep ();

	for (;;) {

	for (;;) {

		error = posix_lock_file(filp, fl);

		error = posix_lock_file(filp, fl, NULL);

		if ((error != -EAGAIN) || !(fl->fl_flags & FL_SLEEP))

		if ((error != -EAGAIN) || !(fl->fl_flags & FL_SLEEP))

			break;

			break;

		error = wait_event_interruptible(fl->fl_wait, !fl->fl_next);

		error = wait_event_interruptible(fl->fl_wait, !fl->fl_next);
@@ -1123,7 +1110,7 @@ int locks_mandatory_area(int read_write, struct inode *inode, 
	fl.fl_end = offset + count - 1;

	fl.fl_end = offset + count - 1;





	for (;;) {

	for (;;) {

		error = __posix_lock_file_conf(inode, &fl, NULL);

		error = __posix_lock_file(inode, &fl, NULL);

		if (error != -EAGAIN)

		if (error != -EAGAIN)

			break;

			break;

		if (!(fl.fl_flags & FL_SLEEP))

		if (!(fl.fl_flags & FL_SLEEP))
@@ -1703,13 +1690,21 @@ out: 
 * @filp: The file to apply the lock to

 * @filp: The file to apply the lock to

 * @cmd: type of locking operation (F_SETLK, F_GETLK, etc.)

 * @cmd: type of locking operation (F_SETLK, F_GETLK, etc.)

 * @fl: The lock to be applied

 * @fl: The lock to be applied

 * @conf: Place to return a copy of the conflicting lock, if found.

 *

 * A caller that doesn't care about the conflicting lock may pass NULL

 * as the final argument.

 *

 * If the filesystem defines a private ->lock() method, then @conf will

 * be left unchanged; so a caller that cares should initialize it to

 * some acceptable default.

 */

 */

int vfs_lock_file(struct file *filp, unsigned int cmd, struct file_lock *fl)

int vfs_lock_file(struct file *filp, unsigned int cmd, struct file_lock *fl, struct file_lock *conf)

{

{

	if (filp->f_op && filp->f_op->lock)

	if (filp->f_op && filp->f_op->lock)

		return filp->f_op->lock(filp, cmd, fl);

		return filp->f_op->lock(filp, cmd, fl);

	else

	else

		return posix_lock_file(filp, fl);

		return posix_lock_file(filp, fl, conf);

}

}

EXPORT_SYMBOL_GPL(vfs_lock_file);

EXPORT_SYMBOL_GPL(vfs_lock_file);
@@ -1776,7 +1771,7 @@ again: 
		goto out;

		goto out;





	for (;;) {

	for (;;) {

		error = vfs_lock_file(filp, cmd, file_lock);

		error = vfs_lock_file(filp, cmd, file_lock, NULL);

		if (error != -EAGAIN || cmd == F_SETLK)

		if (error != -EAGAIN || cmd == F_SETLK)

			break;

			break;

		error = wait_event_interruptible(file_lock->fl_wait,

		error = wait_event_interruptible(file_lock->fl_wait,
@@ -1902,7 +1897,7 @@ again: 
		goto out;

		goto out;





	for (;;) {

	for (;;) {

		error = vfs_lock_file(filp, cmd, file_lock);

		error = vfs_lock_file(filp, cmd, file_lock, NULL);

		if (error != -EAGAIN || cmd == F_SETLK64)

		if (error != -EAGAIN || cmd == F_SETLK64)

			break;

			break;

		error = wait_event_interruptible(file_lock->fl_wait,

		error = wait_event_interruptible(file_lock->fl_wait,
@@ -1956,7 +1951,7 @@ void locks_remove_posix(struct file *filp, fl_owner_t owner) 
	lock.fl_ops = NULL;

	lock.fl_ops = NULL;

	lock.fl_lmops = NULL;

	lock.fl_lmops = NULL;





	vfs_lock_file(filp, F_SETLK, &lock);

	vfs_lock_file(filp, F_SETLK, &lock, NULL);





	if (lock.fl_ops && lock.fl_ops->fl_release_private)

	if (lock.fl_ops && lock.fl_ops->fl_release_private)

		lock.fl_ops->fl_release_private(&lock);

		lock.fl_ops->fl_release_private(&lock);

fs/nfsd/nfs4state.c

+6 −4
Original line number Original line Diff line number Diff line
@@ -2657,6 +2657,7 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, 
	struct file_lock conflock;

	struct file_lock conflock;

	__be32 status = 0;

	__be32 status = 0;

	unsigned int strhashval;

	unsigned int strhashval;

	unsigned int cmd;

	int err;

	int err;





	dprintk("NFSD: nfsd4_lock: start=%Ld length=%Ld\n",

	dprintk("NFSD: nfsd4_lock: start=%Ld length=%Ld\n",
@@ -2739,10 +2740,12 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, 
		case NFS4_READ_LT:

		case NFS4_READ_LT:

		case NFS4_READW_LT:

		case NFS4_READW_LT:

			file_lock.fl_type = F_RDLCK;

			file_lock.fl_type = F_RDLCK;

			cmd = F_SETLK;

		break;

		break;

		case NFS4_WRITE_LT:

		case NFS4_WRITE_LT:

		case NFS4_WRITEW_LT:

		case NFS4_WRITEW_LT:

			file_lock.fl_type = F_WRLCK;

			file_lock.fl_type = F_WRLCK;

			cmd = F_SETLK;

		break;

		break;

		default:

		default:

			status = nfserr_inval;

			status = nfserr_inval;
@@ -2769,9 +2772,8 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, 




	/* XXX?: Just to divert the locks_release_private at the start of

	/* XXX?: Just to divert the locks_release_private at the start of

	 * locks_copy_lock: */

	 * locks_copy_lock: */

	conflock.fl_ops = NULL;

	locks_init_lock(&conflock);

	conflock.fl_lmops = NULL;

	err = posix_lock_file(filp, &file_lock, &conflock);

	err = posix_lock_file_conf(filp, &file_lock, &conflock);

	switch (-err) {

	switch (-err) {

	case 0: /* success! */

	case 0: /* success! */

		update_stateid(&lock_stp->st_stateid);

		update_stateid(&lock_stp->st_stateid);
@@ -2933,7 +2935,7 @@ nfsd4_locku(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, 
	/*

	/*

	*  Try to unlock the file in the VFS.

	*  Try to unlock the file in the VFS.

	*/

	*/

	err = posix_lock_file(filp, &file_lock);

	err = posix_lock_file(filp, &file_lock, NULL);

	if (err) {

	if (err) {

		dprintk("NFSD: nfs4_locku: posix_lock_file failed!\n");

		dprintk("NFSD: nfs4_locku: posix_lock_file failed!\n");

		goto out_nfserr;

		goto out_nfserr;

include/linux/fs.h

+2 −3
Original line number Original line Diff line number Diff line
@@ -852,12 +852,11 @@ extern void locks_copy_lock(struct file_lock *, struct file_lock *); 
extern void locks_remove_posix(struct file *, fl_owner_t);

extern void locks_remove_posix(struct file *, fl_owner_t);

extern void locks_remove_flock(struct file *);

extern void locks_remove_flock(struct file *);

extern int posix_test_lock(struct file *, struct file_lock *);

extern int posix_test_lock(struct file *, struct file_lock *);

extern int posix_lock_file_conf(struct file *, struct file_lock *, struct file_lock *);

extern int posix_lock_file(struct file *, struct file_lock *, struct file_lock *);

extern int posix_lock_file(struct file *, struct file_lock *);

extern int posix_lock_file_wait(struct file *, struct file_lock *);

extern int posix_lock_file_wait(struct file *, struct file_lock *);

extern int posix_unblock_lock(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_test_lock(struct file *, struct file_lock *);

extern int vfs_lock_file(struct file *, unsigned int, struct file_lock *);

extern int vfs_lock_file(struct file *, unsigned int, struct file_lock *, struct file_lock *);

extern int flock_lock_file_wait(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 int __break_lease(struct inode *inode, unsigned int flags);

extern void lease_get_mtime(struct inode *, struct timespec *time);

extern void lease_get_mtime(struct inode *, struct timespec *time);