Handle cancelled reads. diskdstate->flags_closing is now set and cleared

when a FD is opened and closed, and during storeDiskdReadDone() the
copy and callback are only made if the callbackdata is valid.

This differs from before where the copy would always take place, but
the callback would only occur if the callbackdata was valid.

Note that I'm assert()ing that flags_closing == 0 if the callbackdata is
valid. If this ever gets triggered, I think we have another problem ..

diff --git a/src/fs/diskd/store_io_diskd.cc b/src/fs/diskd/store_io_diskd.cc
index 70a6dd7a531fe9a4defc35931826910f17607d2e..cb30f00eb8b295d6ec7160bfd7183496716307a0 100644 (file)
--- a/src/fs/diskd/store_io_diskd.cc
+++ b/src/fs/diskd/store_io_diskd.cc
@@ -1,6 +1,6 @@
 
 /*
- * $Id: store_io_diskd.cc,v 1.16 2000/10/06 05:00:24 wessels Exp $
+ * $Id: store_io_diskd.cc,v 1.17 2000/11/27 00:03:33 adrian Exp $
  *
  * DEBUG: section 81    Squid-side DISKD I/O functions.
  * AUTHOR: Duane Wessels
@@ -184,6 +184,7 @@ storeDiskdClose(SwapDir * SD, storeIOState * sio)
        debug(50, 1) ("storeDiskdSend CLOSE: %s\n", xstrerror());
        storeDiskdIOCallback(sio, DISK_ERROR);
     }
+    diskdstate->flags.close_request = 1;
     diskd_stats.close.ops++;
 }
 
@@ -194,6 +195,8 @@ storeDiskdRead(SwapDir * SD, storeIOState * sio, char *buf, size_t size, off_t o
     int shm_offset;
     char *rbuf;
     diskdstate_t *diskdstate = sio->fsstate;
+    debug(81, 3) ("storeDiskdRead: dirno %d, fileno %08X\n", sio->swap_dirn, sio->swap_filen);
+    assert(!diskdstate->flags.close_request);
     if (!cbdataValid(sio))
        return;
     if (diskdstate->flags.reading) {
@@ -206,7 +209,6 @@ storeDiskdRead(SwapDir * SD, storeIOState * sio, char *buf, size_t size, off_t o
     sio->read.callback_data = callback_data;
     diskdstate->read_buf = buf;        /* the one passed from above */
     cbdataLock(sio->read.callback_data);
-    debug(81, 3) ("storeDiskdRead: dirno %d, fileno %08X\n", sio->swap_dirn, sio->swap_filen);
     sio->offset = offset;
     diskdstate->flags.reading = 1;
     rbuf = storeDiskdShmGet(SD, &shm_offset);
@@ -234,6 +236,7 @@ storeDiskdWrite(SwapDir * SD, storeIOState * sio, char *buf, size_t size, off_t
     int shm_offset;
     diskdstate_t *diskdstate = sio->fsstate;
     debug(81, 3) ("storeDiskdWrite: dirno %d, fileno %08X\n", SD->index, sio->swap_filen);
+    assert(!diskdstate->flags.close_request);
     if (!cbdataValid(sio)) {
        free_func(buf);
        return;
@@ -355,14 +358,22 @@ storeDiskdReadDone(diomsg * M)
     diskd_stats.read.success++;
     sbuf = diskdinfo->shm.buf + M->shm_offset;
     len = M->status;
-    xmemcpy(their_buf, sbuf, len);     /* yucky copy */
     sio->offset += len;
     assert(callback);
     assert(their_data);
     sio->read.callback = NULL;
     sio->read.callback_data = NULL;
-    if (valid)
+    if (valid) {
+        assert(!diskdstate->flags.close_request);
+        /*
+         * Only copy the data if the callback is still valid,
+         * if it isn't valid then the request should have been
+         * aborted.
+         *   -- adrian
+         */
+        xmemcpy(their_buf, sbuf, len); /* yucky copy */
        callback(their_data, their_buf, len);
+    }
 }
 
 static void