[Xen-devel] [PATCH][2/4][IOMGR] Add I/O request manager interface into blkback

["Satoshi Uchida" <s-uchida@xxxxxxxxxxxxx>]

This patch adds I/O request management interface into blkback.

 --------------------------------------------------
 Satoshi UCHIDA 
    NEC Corporation, Japan


# HG changeset patch
# User s-uchida@xxxxxxxxxxxxx
# Date 1184302092 -32400
# Node ID ce1e6cb8e92dc12d16ecb8f8a3a02cb2773e54e3
# Parent  f4ebae5f227414614258f68f358f4dcb0d4ebb51
[IOMGR,BLKBACK] Add I/O request management for virtual block devices into 
blkback.

  Signed-off-by  Satoshi UCHIDA <s-uchida@xxxxxxxxxxxxx>

diff -r f4ebae5f2274 -r ce1e6cb8e92d drivers/xen/blkback/blkback.c
--- a/drivers/xen/blkback/blkback.c     Fri Jul 13 13:45:30 2007 +0900
+++ b/drivers/xen/blkback/blkback.c     Fri Jul 13 13:48:12 2007 +0900
@@ -41,6 +41,10 @@
 #include <xen/balloon.h>
 #include <asm/hypervisor.h>
 #include "common.h"
+
+#ifdef CONFIG_XEN_IOMGR
+#include <xen/iomgr.h>
+#endif
 
 /*
  * These are rather arbitrary. They are fairly large because adjacent requests
@@ -138,6 +142,10 @@ static void free_req(pending_req_t *req)
        spin_unlock_irqrestore(&pending_free_lock, flags);
        if (was_empty)
                wake_up(&pending_free_wq);
+
+#ifdef CONFIG_XEN_IOMGR
+       do_iomgr_free_request(req->blkif->be->dev);
+#endif
 }
 
 static void unplug_queue(blkif_t *blkif)
@@ -206,6 +214,10 @@ int blkif_schedule(void *arg)
 
        if (debug_lvl)
                printk(KERN_DEBUG "%s: started\n", current->comm);
+
+#ifdef CONFIG_XEN_IOMGR
+       do_iomgr_dev_start(blkif->be->dev);
+#endif
 
        while (!kthread_should_stop()) {
                if(try_to_freeze())
@@ -218,6 +230,10 @@ int blkif_schedule(void *arg)
                        pending_free_wq,
                        !list_empty(&pending_free) || kthread_should_stop());
 
+#ifdef CONFIG_XEN_IOMGR
+               do_iomgr_waiting_request(blkif->be->dev);
+#endif
+
                blkif->waiting_reqs = 0;
                smp_mb(); /* clear flag *before* checking for work */
 
@@ -233,6 +249,10 @@ int blkif_schedule(void *arg)
                print_stats(blkif);
        if (debug_lvl)
                printk(KERN_DEBUG "%s: exiting\n", current->comm);
+
+#ifdef CONFIG_XEN_IOMGR
+       do_iomgr_dev_stop(blkif->be->dev);
+#endif
 
        blkif->xenblkd = NULL;
        blkif_put(blkif);
@@ -316,11 +336,25 @@ static int do_block_io_op(blkif_t *blkif
                if (RING_REQUEST_CONS_OVERFLOW(&blk_rings->common, rc))
                        break;
 
+#ifdef CONFIG_XEN_IOMGR
+               if (do_iomgr_allow_request(blkif->be->dev)) {
+                       more_to_do = 1;
+                       break;
+               }
+#endif
+
                pending_req = alloc_req();
                if (NULL == pending_req) {
+#ifdef CONFIG_XEN_IOMGR
+                       do_iomgr_oo_abort_request(blkif->be->dev);
+#endif
                        blkif->st_oo_req++;
                        more_to_do = 1;
                        break;
+#ifdef CONFIG_XEN_IOMGR
+               } else {
+                       do_iomgr_alloc_request(blkif->be->dev);
+#endif
                }
 
                switch (blkif->blk_protocol) {
diff -r f4ebae5f2274 -r ce1e6cb8e92d drivers/xen/blkback/common.h
--- a/drivers/xen/blkback/common.h      Fri Jul 13 13:45:30 2007 +0900
+++ b/drivers/xen/blkback/common.h      Fri Jul 13 13:48:12 2007 +0900
@@ -96,6 +96,16 @@ typedef struct blkif_st {
        grant_ref_t    shmem_ref;
 } blkif_t;
 
+struct backend_info
+{
+       struct xenbus_device *dev;
+       blkif_t *blkif;
+       struct xenbus_watch backend_watch;
+       unsigned major;
+       unsigned minor;
+       char *mode;
+};
+
 blkif_t *blkif_alloc(domid_t domid);
 void blkif_disconnect(blkif_t *blkif);
 void blkif_free(blkif_t *blkif);
diff -r f4ebae5f2274 -r ce1e6cb8e92d drivers/xen/blkback/xenbus.c
--- a/drivers/xen/blkback/xenbus.c      Fri Jul 13 13:45:30 2007 +0900
+++ b/drivers/xen/blkback/xenbus.c      Fri Jul 13 13:48:12 2007 +0900
@@ -26,16 +26,6 @@
 #define DPRINTK(fmt, args...)                          \
        pr_debug("blkback/xenbus (%s:%d) " fmt ".\n",   \
                 __FUNCTION__, __LINE__, ##args)
-
-struct backend_info
-{
-       struct xenbus_device *dev;
-       blkif_t *blkif;
-       struct xenbus_watch backend_watch;
-       unsigned major;
-       unsigned minor;
-       char *mode;
-};
 
 static void connect(struct backend_info *);
 static int connect_ring(struct backend_info *);


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