(diskfs_truncate): Don't acquire writer lock on NP->dn->allocptrlock

until after forcing delayed copies through; otherwise the pageins will
deadlock attempting to get a reader lock to service them.  This is
safe, because we only need NP->allocsize here, and that can't change
as long as we hold NP->lock.

1 files changed, 6 insertions, 6 deletions

diff --git a/ufs/sizes.c b/ufs/sizes.c
index bf9e2c38..ef7666b1 100644
--- a/ufs/sizes.c
+++ b/ufs/sizes.c
@@ -1,5 +1,5 @@
 /* File growth and truncation
-   Copyright (C) 1993, 1994 Free Software Foundation
+   Copyright (C) 1993, 1994, 1995 Free Software Foundation
 
 This file is part of the GNU Hurd.
 
@@ -83,13 +83,11 @@ diskfs_truncate (struct node *np,
       diskfs_file_update (np, 1);
     }
 
-  rwlock_writer_lock (&np->dn->allocptrlock);
-
   /* Now flush all the data past the new size from the kernel.
      Also force any delayed copies of this data to take place
-     immediately.  (We are changing the data implicitly to zeros
-     and doing it without the kernels immediate knowledge;
-     this forces us to help out the kernel thusly.) */
+     immediately.  (We are implicitly changing the data to zeros
+     and doing it without the kernel's immediate knowledge;
+     accordingl we must help out the kernel thusly.) */
   spin_lock (&node2pagelock);
   upi = np->dn->fileinfo;
   if (upi)
@@ -110,6 +108,8 @@ diskfs_truncate (struct node *np,
       pager_unreference (upi->p);
     }
 
+  rwlock_writer_lock (&np->dn->allocptrlock);
+
   /* Update the size on disk; fsck will finish freeing blocks if necessary
      should we crash. */
   np->dn_stat.st_size = length;