Submitting a patch for NFS locking that has been part of the -ac tree
since 2.4.2-ac4 but has never picked-up in the base kernel.
The NFS locking routines (nlmsvc_lock and others in svclock.c) go directly
to the default kernel operations (eg., posix_lock_file) and do not invoke
any filesystem lock operation that may have been provided. They SHOULD
invoke the lock file_operation (if one exists for the filesystem)
similarly to the non-NFS fcntl_setlk which does the following:
if (filp->f_op->lock != NULL) {
error = filp->f_op->lock(filp, cmd, &file_lock);
Without this, a filesystem that needs to provide the lock operation has no
way to achieve proper locking via nfs clients.
diff -Naur linux-2.4.10/fs/lockd/svclock.c linux-2.4.10-patch/fs/lockd/svclock.c
--- linux-2.4.10/fs/lockd/svclock.c Mon Oct 8 10:12:36 2001
+++ linux-2.4.10-patch/fs/lockd/svclock.c Mon Oct 8 10:13:37 2001
@@ -237,6 +237,14 @@
if (unlock && block->b_granted) {
dprintk("lockd: deleting granted lock\n");
fl->fl_type = F_UNLCK;
+
+ /* If the filesystem defined its own lock operation, invoke it. */
+ if ((block->b_file->f_file.f_op) && (block->b_file->f_file.f_op->lock)) {
+ int error;
+ error = block->b_file->f_file.f_op->lock(&block->b_file->f_file, F_SETLK, fl);
+ dprintk("nlmsvc_delete_block: filesystem (un)lock operation returned %d\n", error);
+ }
+
posix_lock_file(&block->b_file->f_file, fl, 0);
block->b_granted = 0;
} else {
@@ -319,7 +327,16 @@
again:
if (!(conflock = posix_test_lock(&file->f_file, &lock->fl))) {
- error = posix_lock_file(&file->f_file, &lock->fl, 0);
+
+ /* If the filesystem defined its own lock operation, invoke it. */
+ error = 0;
+ if ((file->f_file.f_op) && (file->f_file.f_op->lock)) {
+ error = file->f_file.f_op->lock(&file->f_file, F_SETLK, &lock->fl);
+ dprintk("nlmsvc_lock: filesystem lock operation returned %d\n", error);
+ }
+
+ if (error == 0)
+ error = posix_lock_file(&file->f_file, &lock->fl, 0);
if (block)
nlmsvc_delete_block(block, 0);
@@ -348,6 +365,11 @@
return nlm_lck_denied;
}
+ if (posix_locks_deadlock(&lock->fl, conflock)) {
+ up(&file->f_sema);
+ return nlm_lck_denied; /* EDEADLK */
+ }
+
/* If we don't have a block, create and initialize it. Then
* retry because we may have slept in kmalloc. */
if (block == NULL) {
@@ -357,6 +379,11 @@
goto again;
}
+ if (!conflock) {
+ printk("nlmsvc_lock: BUG! Trying to block without a conflock!\n");
+ BUG();
+ }
+
/* Append to list of blocked */
nlmsvc_insert_block(block, NLM_NEVER);
@@ -387,6 +414,22 @@
(long long)lock->fl.fl_start,
(long long)lock->fl.fl_end);
+ /* If the filesystem defined its own lock operation, invoke it. */
+ if ((file->f_file.f_op) && (file->f_file.f_op->lock)) {
+ int error;
+
+ error = file->f_file.f_op->lock(&file->f_file, F_GETLK, &lock->fl);
+ if ((!error) && (lock->fl.fl_type != F_UNLCK))
+ {
+ conflock->caller = "somehost"; /* FIXME */
+ conflock->oh.len = 0; /* don't return OH info */
+ conflock->fl = lock->fl;
+ dprintk("nlmsvc_testlock: filesystem (get)lock operation returned error %d type %d pid %d start %Ld end %Ld\n",
+ error, lock->fl.fl_type, lock->fl.fl_pid, lock->fl.fl_start, lock->fl.fl_end);
+ return nlm_lck_denied;
+ }
+ }
+
if ((fl = posix_test_lock(&file->f_file, &lock->fl)) != NULL) {
dprintk("lockd: conflicting lock(ty=%d, %Ld-%Ld)\n",
fl->fl_type, (long long)fl->fl_start,
@@ -423,7 +466,16 @@
nlmsvc_cancel_blocked(file, lock);
lock->fl.fl_type = F_UNLCK;
- error = posix_lock_file(&file->f_file, &lock->fl, 0);
+
+ /* If the filesystem defined its own lock operation, invoke it. */
+ error = 0;
+ if ((file->f_file.f_op) && (file->f_file.f_op->lock)) {
+ error = file->f_file.f_op->lock(&file->f_file, F_SETLK, &lock->fl);
+ dprintk("nlmsvc_unlock: filesystem (un)lock operation returned error %d\n", error);
+ }
+
+ if (error == 0)
+ error = posix_lock_file(&file->f_file, &lock->fl, 0);
return (error < 0)? nlm_lck_denied_nolocks : nlm_granted;
}
@@ -515,6 +567,50 @@
}
/* Try the lock operation again */
+
+ /* If the filesystem defined its own lock operation, invoke it. */
+ if ((file->f_file.f_op) && (file->f_file.f_op->lock)) {
+ struct file_lock getlock;
+
+ /* save requestor lock inforation since GETLK will overwrite it */
+ getlock.fl_pid = lock->fl.fl_pid;
+ getlock.fl_type = lock->fl.fl_type;
+ getlock.fl_start = lock->fl.fl_start;
+ getlock.fl_end = lock->fl.fl_end;
+
+ error = file->f_file.f_op->lock(&file->f_file, F_GETLK, &lock->fl);
+
+ /* restore requestor lock inforation. */
+ lock->fl.fl_pid = getlock.fl_pid;
+ lock->fl.fl_type = getlock.fl_type;
+ lock->fl.fl_start = getlock.fl_start;
+ lock->fl.fl_end = getlock.fl_end;
+
+ if ((!error) && (lock->fl.fl_type != F_UNLCK)) {
+ dprintk("nlmsvc_grant_blocked: filesystem (get)lock operation returned error %d type %d pid %d start %Ld end %Ld\n",
+ error, lock->fl.fl_type, lock->fl.fl_pid, lock->fl.fl_start, lock->fl.fl_end);
+ dprintk("lockd: lock still blocked\n");
+
+ /* If the blocker is local and recorded in the vfs lock structures, use its
+ conflock to wait on. If the lock is denied due to the filesystem call, we
+ don't have a conflicting lock so retry in a while. */
+
+ if ((conflock = posix_test_lock(&file->f_file, &lock->fl)) != NULL) {
+ nlmsvc_insert_block(block, NLM_NEVER);
+ posix_block_lock(conflock, &lock->fl);
+ up(&file->f_sema);
+ return;
+ }
+ else {
+ dprintk("nlmsvc_grant_blocked: NO conflock RECORDED IN THE VFS!\n");
+ nlmsvc_insert_block(block, jiffies + 30 * HZ);
+ up(&file->f_sema);
+ return;
+ }
+
+ }
+ }
+
if ((conflock = posix_test_lock(&file->f_file, &lock->fl)) != NULL) {
/* Bummer, we blocked again */
dprintk("lockd: lock still blocked\n");
@@ -528,6 +624,20 @@
* following yields an error, this is most probably due to low
* memory. Retry the lock in a few seconds.
*/
+
+ /* If the filesystem defined its own lock operation, invoke it. */
+ if ((file->f_file.f_op) && (file->f_file.f_op->lock)) {
+ error = file->f_file.f_op->lock(&file->f_file, F_SETLK, &lock->fl);
+ dprintk("nlmsvc_grant_blocked: filesystem lock operation returned error %d\n", error);
+ if (error) {
+ printk(KERN_WARNING "lockd: unexpected error %d in %s!\n",
+ error, __FUNCTION__);
+ nlmsvc_insert_block(block, jiffies + 10 * HZ);
+ up(&file->f_sema);
+ return;
+ }
+ }
+
if ((error = posix_lock_file(&file->f_file, &lock->fl, 0)) < 0) {
printk(KERN_WARNING "lockd: unexpected error %d in %s!\n",
-error, __FUNCTION__);
diff -Naur linux-2.4.10/fs/locks.c linux-2.4.10-patch/fs/locks.c
--- linux-2.4.10/fs/locks.c Mon Oct 8 10:12:28 2001
+++ linux-2.4.10-patch/fs/locks.c Mon Oct 8 10:13:30 2001
@@ -660,7 +660,7 @@
* from a broken NFS client. But broken NFS clients have a lot more to
* worry about than proper deadlock detection anyway... --okir
*/
-static int posix_locks_deadlock(struct file_lock *caller_fl,
+int posix_locks_deadlock(struct file_lock *caller_fl,
struct file_lock *block_fl)
{
struct list_head *tmp;
diff -Naur linux-2.4.10/include/linux/fs.h linux-2.4.10-patch/include/linux/fs.h
--- linux-2.4.10/include/linux/fs.h Mon Oct 8 10:12:48 2001
+++ linux-2.4.10-patch/include/linux/fs.h Mon Oct 8 10:13:52 2001
@@ -605,6 +605,7 @@
extern int posix_lock_file(struct file *, struct file_lock *, unsigned int);
extern void posix_block_lock(struct file_lock *, struct file_lock *);
extern void posix_unblock_lock(struct file_lock *);
+extern int posix_locks_deadlock(struct file_lock *, struct file_lock *);
extern int __get_lease(struct inode *inode, unsigned int flags);
extern time_t lease_get_mtime(struct inode *);
extern int lock_may_read(struct inode *, loff_t start, unsigned long count);
diff -Naur linux-2.4.10/kernel/ksyms.c linux-2.4.10-patch/kernel/ksyms.c
--- linux-2.4.10/kernel/ksyms.c Mon Oct 8 10:13:00 2001
+++ linux-2.4.10-patch/kernel/ksyms.c Mon Oct 8 10:13:59 2001
@@ -223,6 +223,7 @@
EXPORT_SYMBOL(posix_test_lock);
EXPORT_SYMBOL(posix_block_lock);
EXPORT_SYMBOL(posix_unblock_lock);
+EXPORT_SYMBOL(posix_locks_deadlock);
EXPORT_SYMBOL(locks_mandatory_area);
EXPORT_SYMBOL(dput);
EXPORT_SYMBOL(have_submounts);
-
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This archive was generated by hypermail 2b29 : Tue May 07 2002 - 22:00:21 EST