[PATCH] fix pf request handling

Here's the patch from

http://bugzilla.kernel.org/show_bug.cgi?id=4853

It is a feeble attempt at fixing the request handling in pf, it is totally
foobar right now.

Signed-off-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 16 insertions, 6 deletions

diff --git a/drivers/block/paride/pf.c b/drivers/block/paride/pf.c
index 711d2f314ac3..94af920465b5 100644
--- a/drivers/block/paride/pf.c
+++ b/drivers/block/paride/pf.c
@@ -750,6 +750,14 @@ static int pf_ready(void)
 
 static struct request_queue *pf_queue;
 
+static void pf_end_request(int uptodate)
+{
+        if (pf_req) {
+                end_request(pf_req, uptodate);
+                pf_req = NULL;
+        }
+}
+
 static void do_pf_request(request_queue_t * q)
 {
         if (pf_busy)
@@ -765,7 +773,7 @@ repeat:
         pf_count = pf_req->current_nr_sectors;
 
         if (pf_block + pf_count > get_capacity(pf_req->rq_disk)) {
-                end_request(pf_req, 0);
+                pf_end_request(0);
                 goto repeat;
         }
 
@@ -780,7 +788,7 @@ repeat:
                 pi_do_claimed(pf_current->pi, do_pf_write);
         else {
                 pf_busy = 0;
-                end_request(pf_req, 0);
+                pf_end_request(0);
                 goto repeat;
         }
 }
@@ -798,9 +806,11 @@ static int pf_next_buf(void)
         if (!pf_count)
                 return 1;
         spin_lock_irqsave(&pf_spin_lock, saved_flags);
-        end_request(pf_req, 1);
-        pf_count = pf_req->current_nr_sectors;
-        pf_buf = pf_req->buffer;
+        pf_end_request(1);
+        if (pf_req) {
+                pf_count = pf_req->current_nr_sectors;
+                pf_buf = pf_req->buffer;
+        }
         spin_unlock_irqrestore(&pf_spin_lock, saved_flags);
         return 1;
 }
@@ -810,7 +820,7 @@ static inline void next_request(int success)
         unsigned long saved_flags;
 
         spin_lock_irqsave(&pf_spin_lock, saved_flags);
-        end_request(pf_req, success);
+        pf_end_request(success);
         pf_busy = 0;
         do_pf_request(pf_queue);
         spin_unlock_irqrestore(&pf_spin_lock, saved_flags);