[PATCH] pktcdvd: bio write congestion using congestion_wait()

This adds a bio write queue congestion control to the pktcdvd driver with
fixed on/off marks.  It prevents that the driver consumes a unlimited
amount of write requests.

[akpm@osdl.org: sync with congestion_wait() renaming]
Signed-off-by: Thomas Maier <balagi@justmail.de>
Cc: Peter Osterlund <petero2@telia.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 9 insertions, 0 deletions

diff --git a/include/linux/pktcdvd.h b/include/linux/pktcdvd.h
index 8a94c717c266..9b1a185fb1e5 100644
--- a/include/linux/pktcdvd.h
+++ b/include/linux/pktcdvd.h
@@ -112,6 +112,12 @@ struct pkt_ctrl_command {
 #include <linux/completion.h>
 #include <linux/cdrom.h>
 
+
+/* default bio write queue congestion marks */
+#define PKT_WRITE_CONGESTION_ON    10000
+#define PKT_WRITE_CONGESTION_OFF   9000
+
+
 struct packet_settings
 {
         __u32                   size;           /* packet size in (512 byte) sectors */
@@ -271,6 +277,9 @@ struct pktcdvd_device
 
         struct packet_iosched   iosched;
         struct gendisk          *disk;
+
+        int                     write_congestion_off;
+        int                     write_congestion_on;
 };
 
 #endif /* __KERNEL__ */