From 88232ecd55e162d2ab3029fb58791cfd7a337cb3 Mon Sep 17 00:00:00 2001
Message-Id: <88232ecd55e162d2ab3029fb58791cfd7a337cb3.1350493760.git.minovotn@redhat.com>
In-Reply-To: <c93188b6c6973932d2adaa52e6a4920db13b4e62.1350493760.git.minovotn@redhat.com>
References: <c93188b6c6973932d2adaa52e6a4920db13b4e62.1350493760.git.minovotn@redhat.com>
From: Jeffrey Cody <jcody@redhat.com>
Date: Wed, 17 Oct 2012 05:59:38 +0200
Subject: [PATCH 25/35] block: convert bdrv_commit() to use bdrv_reopen()

RH-Author: Jeffrey Cody <jcody@redhat.com>
Message-id: <67674b515e98d673901e3b09c8a76f5b1bfd3650.1350447475.git.jcody@redhat.com>
Patchwork-id: 43284
O-Subject: [RHEL6.4 qemu-kvm PATCH v4 25/35] block: convert bdrv_commit() to use bdrv_reopen()
Bugzilla: 767233
RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>
RH-Acked-by: Eric Blake <eblake@redhat.com>
RH-Acked-by: Kevin Wolf <kwolf@redhat.com>

Currently, bdrv_commit() reopens images r/w itself, via risky
_delete() and _open() calls. Use the new safe method for drive reopen.

Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
(cherry picked from commit 0bce597d6ec34b2af802799eb53ebc863c704d05)
---
 block.c | 48 +++++-------------------------------------------
 1 file changed, 5 insertions(+), 43 deletions(-)

Signed-off-by: Michal Novotny <minovotn@redhat.com>
---
 block.c | 48 +++++-------------------------------------------
 1 file changed, 5 insertions(+), 43 deletions(-)

diff --git a/block.c b/block.c
index 5c4b2bd..17d3886 100644
--- a/block.c
+++ b/block.c
@@ -1309,13 +1309,11 @@ int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res)
 int bdrv_commit(BlockDriverState *bs)
 {
     BlockDriver *drv = bs->drv;
-    BlockDriver *backing_drv;
     int64_t sector, total_sectors;
     int n, ro, open_flags;
-    int ret = 0, rw_ret = 0;
+    int ret = 0;
     uint8_t *buf;
     char filename[1024];
-    BlockDriverState *bs_rw, *bs_ro;
 
     if (!drv)
         return -ENOMEDIUM;
@@ -1324,42 +1322,18 @@ int bdrv_commit(BlockDriverState *bs)
         return -ENOTSUP;
     }
 
-    if (bs->backing_hd->keep_read_only) {
-        return -EACCES;
-    }
-
     if (bdrv_in_use(bs) || bdrv_in_use(bs->backing_hd)) {
         return -EBUSY;
     }
 
-    backing_drv = bs->backing_hd->drv;
     ro = bs->backing_hd->read_only;
     strncpy(filename, bs->backing_hd->filename, sizeof(filename));
     open_flags =  bs->backing_hd->open_flags;
 
     if (ro) {
-        /* re-open as RW */
-        bdrv_delete(bs->backing_hd);
-        bs->backing_hd = NULL;
-        bs_rw = bdrv_new("");
-        rw_ret = bdrv_open(bs_rw, filename, open_flags | BDRV_O_RDWR,
-            backing_drv);
-        if (rw_ret < 0) {
-            bdrv_delete(bs_rw);
-            /* try to re-open read-only */
-            bs_ro = bdrv_new("");
-            ret = bdrv_open(bs_ro, filename, open_flags & ~BDRV_O_RDWR,
-                backing_drv);
-            if (ret < 0) {
-                bdrv_delete(bs_ro);
-                /* drive not functional anymore */
-                bs->drv = NULL;
-                return ret;
-            }
-            bs->backing_hd = bs_ro;
-            return rw_ret;
+        if (bdrv_reopen(bs->backing_hd, open_flags | BDRV_O_RDWR, NULL)) {
+            return -EACCES;
         }
-        bs->backing_hd = bs_rw;
     }
 
     total_sectors = bdrv_getlength(bs) >> BDRV_SECTOR_BITS;
@@ -1396,20 +1370,8 @@ ro_cleanup:
     g_free(buf);
 
     if (ro) {
-        /* re-open as RO */
-        bdrv_delete(bs->backing_hd);
-        bs->backing_hd = NULL;
-        bs_ro = bdrv_new("");
-        ret = bdrv_open(bs_ro, filename, open_flags & ~BDRV_O_RDWR,
-            backing_drv);
-        if (ret < 0) {
-            bdrv_delete(bs_ro);
-            /* drive not functional anymore */
-            bs->drv = NULL;
-            return ret;
-        }
-        bs->backing_hd = bs_ro;
-        bs->backing_hd->keep_read_only = 0;
+        /* ignoring error return here */
+        bdrv_reopen(bs->backing_hd, open_flags & ~BDRV_O_RDWR, NULL);
     }
 
     return ret;
-- 
1.7.11.7