re: [PATCH] NFS locking routines do not invoke the filesystem lock operation

From: Brian Dixon (dixonbp@us.ibm.com)
Date: Mon Mar 24 2003 - 12:10:20 EST


There is a problem with the getlk part of the original patch for this.
Here is a more recent patch that includes the fix.

-Brian

diff -Naur linux-2.4.19/fs/lockd/svclock.c linux-2.4.19-patches/fs/lockd/svclock.c
--- linux-2.4.19/fs/lockd/svclock.c Thu Oct 11 09:52:18 2001
+++ linux-2.4.19-patches/fs/lockd/svclock.c Tue Oct 1 15:02:49 2002
@@ -242,6 +242,14 @@
      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 {
@@ -324,7 +332,16 @@

 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);
@@ -392,6 +409,21 @@
                        (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,
@@ -428,7 +460,16 @@
      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;
 }
@@ -520,6 +561,52 @@
      }

      /* 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;
+ unsigned char found_type;
+
+ /* 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);
+ found_type = lock->fl.fl_type;
+
+ /* 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) && (found_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");
@@ -533,6 +620,20 @@
       * 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__);

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This archive was generated by hypermail 2b29 : Mon Mar 31 2003 - 22:00:16 EST