Re: nfs client oops, all 2.4 kernels

From: Trond Myklebust (trond.myklebust@fys.uio.no)
Date: Tue Sep 11 2001 - 08:15:34 EST


>>>>> " " == Trond Myklebust <trond.myklebust@fys.uio.no> writes:

> Could you check if the appended patch works?

The previous patch had a bug in the rewrite of locks_delete_lock()
which will Oops/corrupt the inode->i_flock list. Please consign to
/dev/null, and try the following instead.

(Note to self: Never attempt to write any patches *before* lunch...)

Cheers,
   Trond

--- linux-2.4.9/fs/locks.c.orig Thu Jul 5 00:39:28 2001
+++ linux-2.4.9/fs/locks.c Tue Sep 11 15:09:13 2001
@@ -473,21 +473,26 @@
                 fl->fl_insert(fl);
 }
 
-/* Delete a lock and then free it.
- * Remove our lock from the lock lists, wake up processes that are blocked
- * waiting for this lock, notify the FS that the lock has been cleared and
- * finally free the lock.
+/*
+ * Remove lock from the lock lists
  */
-static void locks_delete_lock(struct file_lock **thisfl_p, unsigned int wait)
+static inline void _unhash_lock(struct file_lock **thisfl_p)
 {
         struct file_lock *fl = *thisfl_p;
 
         *thisfl_p = fl->fl_next;
         fl->fl_next = NULL;
 
- list_del(&fl->fl_link);
- INIT_LIST_HEAD(&fl->fl_link);
+ list_del_init(&fl->fl_link);
+}
 
+/*
+ * Wake up processes that are blocked waiting for this lock,
+ * notify the FS that the lock has been cleared and
+ * finally free the lock.
+ */
+static inline void _delete_lock(struct file_lock *fl, unsigned int wait)
+{
         fasync_helper(0, fl->fl_file, 0, &fl->fl_fasync);
         if (fl->fl_fasync != NULL){
                 printk(KERN_ERR "locks_delete_lock: fasync == %p\n", fl->fl_fasync);
@@ -502,6 +507,17 @@
 }
 
 /*
+ * Delete a lock and then free it.
+ */
+static void locks_delete_lock(struct file_lock **thisfl_p, unsigned int wait)
+{
+ struct file_lock *fl = *thisfl_p;
+
+ _unhash_lock(thisfl_p);
+ _delete_lock(fl, wait);
+}
+
+/*
  * Call back client filesystem in order to get it to unregister a lock,
  * then delete lock. Essentially useful only in locks_remove_*().
  * Note: this must be called with the semaphore already held!
@@ -511,12 +527,13 @@
         struct file_lock *fl = *thisfl_p;
         int (*lock)(struct file *, int, struct file_lock *);
 
+ _unhash_lock(thisfl_p);
         if (fl->fl_file->f_op &&
             (lock = fl->fl_file->f_op->lock) != NULL) {
                 fl->fl_type = F_UNLCK;
                 lock(fl->fl_file, F_SETLK, fl);
         }
- locks_delete_lock(thisfl_p, 0);
+ _delete_lock(fl, 0);
 }
 
 /* Determine if lock sys_fl blocks lock caller_fl. Common functionality
@@ -1661,6 +1678,7 @@
         while ((fl = *before) != NULL) {
                 if ((fl->fl_flags & FL_POSIX) && fl->fl_owner == owner) {
                         locks_unlock_delete(before);
+ before = &inode->i_flock;
                         continue;
                 }
                 before = &fl->fl_next;
-
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This archive was generated by hypermail 2b29 : Sat Sep 15 2001 - 21:00:33 EST