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: Marc Eshel <eshel@almaden.ibm.com>
Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c
index 97b0160..3b0e7a4 100644
--- a/fs/lockd/svclock.c
+++ b/fs/lockd/svclock.c
@@ -363,7 +363,7 @@
} else
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;
dprintk("lockd: posix_lock_file returned %d\n", error);
@@ -467,7 +467,7 @@
nlmsvc_cancel_blocked(file, lock);
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;
}
@@ -569,7 +569,7 @@
/* Try the lock operation again */
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;
switch (error) {
diff --git a/fs/lockd/svcsubs.c b/fs/lockd/svcsubs.c
index c0df00c..5095708 100644
--- a/fs/lockd/svcsubs.c
+++ b/fs/lockd/svcsubs.c
@@ -182,7 +182,7 @@
lock.fl_type = F_UNLCK;
lock.fl_start = 0;
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",
__FILE__, __LINE__);
return 1;
diff --git a/fs/locks.c b/fs/locks.c
index f4fd151..ee46584 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -801,7 +801,7 @@
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 *new_fl = NULL;
@@ -1007,6 +1007,7 @@
* posix_lock_file - 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.
*
* Add a POSIX style lock to a file.
* We merge adjacent & overlapping locks whenever possible.
@@ -1016,26 +1017,12 @@
* 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)
-{
- 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,
+int posix_lock_file(struct file *filp, struct file_lock *fl,
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
@@ -1051,7 +1038,7 @@
int error;
might_sleep ();
for (;;) {
- error = posix_lock_file(filp, fl);
+ error = posix_lock_file(filp, fl, NULL);
if ((error != -EAGAIN) || !(fl->fl_flags & FL_SLEEP))
break;
error = wait_event_interruptible(fl->fl_wait, !fl->fl_next);
@@ -1123,7 +1110,7 @@
fl.fl_end = offset + count - 1;
for (;;) {
- error = __posix_lock_file_conf(inode, &fl, NULL);
+ error = __posix_lock_file(inode, &fl, NULL);
if (error != -EAGAIN)
break;
if (!(fl.fl_flags & FL_SLEEP))
@@ -1703,13 +1690,21 @@
* @filp: The file to apply the lock to
* @cmd: type of locking operation (F_SETLK, F_GETLK, etc.)
* @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)
return filp->f_op->lock(filp, cmd, fl);
else
- return posix_lock_file(filp, fl);
+ return posix_lock_file(filp, fl, conf);
}
EXPORT_SYMBOL_GPL(vfs_lock_file);
@@ -1776,7 +1771,7 @@
goto out;
for (;;) {
- error = vfs_lock_file(filp, cmd, file_lock);
+ error = vfs_lock_file(filp, cmd, file_lock, NULL);
if (error != -EAGAIN || cmd == F_SETLK)
break;
error = wait_event_interruptible(file_lock->fl_wait,
@@ -1902,7 +1897,7 @@
goto out;
for (;;) {
- error = vfs_lock_file(filp, cmd, file_lock);
+ error = vfs_lock_file(filp, cmd, file_lock, NULL);
if (error != -EAGAIN || cmd == F_SETLK64)
break;
error = wait_event_interruptible(file_lock->fl_wait,
@@ -1956,7 +1951,7 @@
lock.fl_ops = 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)
lock.fl_ops->fl_release_private(&lock);
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index e42c7a0..03b0578 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -2657,6 +2657,7 @@
struct file_lock conflock;
__be32 status = 0;
unsigned int strhashval;
+ unsigned int cmd;
int err;
dprintk("NFSD: nfsd4_lock: start=%Ld length=%Ld\n",
@@ -2739,10 +2740,12 @@
case NFS4_READ_LT:
case NFS4_READW_LT:
file_lock.fl_type = F_RDLCK;
+ cmd = F_SETLK;
break;
case NFS4_WRITE_LT:
case NFS4_WRITEW_LT:
file_lock.fl_type = F_WRLCK;
+ cmd = F_SETLK;
break;
default:
status = nfserr_inval;
@@ -2769,9 +2772,8 @@
/* XXX?: Just to divert the locks_release_private at the start of
* locks_copy_lock: */
- conflock.fl_ops = NULL;
- conflock.fl_lmops = NULL;
- err = posix_lock_file_conf(filp, &file_lock, &conflock);
+ locks_init_lock(&conflock);
+ err = posix_lock_file(filp, &file_lock, &conflock);
switch (-err) {
case 0: /* success! */
update_stateid(&lock_stp->st_stateid);
@@ -2933,7 +2935,7 @@
/*
* 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) {
dprintk("NFSD: nfs4_locku: posix_lock_file failed!\n");
goto out_nfserr;
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 1d5ccdd..c92d0bd 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -852,12 +852,11 @@
extern void locks_remove_posix(struct file *, fl_owner_t);
extern void locks_remove_flock(struct file *);
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 *);
+extern int posix_lock_file(struct file *, struct file_lock *, 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 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 __break_lease(struct inode *inode, unsigned int flags);
extern void lease_get_mtime(struct inode *, struct timespec *time);