From ef9c4188157e2349ff68710982d9922f4a335b82 Mon Sep 17 00:00:00 2001

From: Jeffrey Cody <jcody@redhat.com>

Date: Mon, 13 Jan 2014 20:52:04 +0100

Subject: [PATCH 12/16] block: vhdx - improve error message, and .bdrv_check implementation

RH-Author: Jeffrey Cody <jcody@redhat.com>

Message-id: <f13406a07edd6ca0f7c7c5a9f87c0376dc4c1663.1389634483.git.jcody@redhat.com>

Patchwork-id: 56643

O-Subject: [RHEL7 qemu-kvm PATCH] block: vhdx - improve error message, and .bdrv_check implementation

Bugzilla: 1035001

RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>

RH-Acked-by: Kevin Wolf <kwolf@redhat.com>

RH-Acked-by: Fam Zheng <famz@redhat.com>

If there is a dirty log file to be replayed in a VHDX image, it is

replayed in .vhdx_open().  However, if the file is opened read-only,

then a somewhat cryptic error message results.

This adds a more helpful error message for the user.  If an image file

contains a log to be replayed, and is opened read-only, the user is

instructed to run 'qemu-img check -r all' on the image file.

Running qemu-img check -r all will cause the image file to be opened

r/w, which will replay the log file.  If a log file replay is detected,

this is flagged, and bdrv_check will increase the corruptions_fixed

count for the image.

[Fixed typo in error message that was pointed out by Eric Blake

<eblake@redhat.com>.

--Stefan]

Signed-off-by: Jeff Cody <jcody@redhat.com>

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

(cherry picked from commit 7e30e6a6746b417c7e0dbc9af009560fbb63f336)

Conflicts:

	block/vhdx.c

RHEL7 Notes:  Conflict due to different order of members in the

              BlockDriver struct.  Resolved so that the order matches

              what is upstream.

BZ 1035001

Brew: http://brewweb.devel.redhat.com/brew/taskinfo?taskID=6861970

Signed-off-by: Jeff Cody <jcody@redhat.com>

---

 block/vhdx-log.c | 13 ++++++++++++-

 block/vhdx.c     | 25 ++++++++++++++++++++++---

 block/vhdx.h     |  5 ++++-

 3 files changed, 38 insertions(+), 5 deletions(-)

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>

---

 block/vhdx-log.c |   13 ++++++++++++-

 block/vhdx.c     |   25 ++++++++++++++++++++++---

 block/vhdx.h     |    5 ++++-

 3 files changed, 38 insertions(+), 5 deletions(-)

diff --git a/block/vhdx-log.c b/block/vhdx-log.c

index ee5583c..8c9ae0d 100644

--- a/block/vhdx-log.c

+++ b/block/vhdx-log.c

@@ -706,7 +706,8 @@ exit:

  *

  * If read-only, we must replay the log in RAM (or refuse to open

  * a dirty VHDX file read-only) */

-int vhdx_parse_log(BlockDriverState *bs, BDRVVHDXState *s, bool *flushed)

+int vhdx_parse_log(BlockDriverState *bs, BDRVVHDXState *s, bool *flushed,

+                   Error **errp)

 {

     int ret = 0;

     VHDXHeader *hdr;

@@ -761,6 +762,16 @@ int vhdx_parse_log(BlockDriverState *bs, BDRVVHDXState *s, bool *flushed)

     }

     if (logs.valid) {

+        if (bs->read_only) {

+            ret = -EPERM;

+            error_setg_errno(errp, EPERM,

+                             "VHDX image file '%s' opened read-only, but "

+                             "contains a log that needs to be replayed.  To "

+                             "replay the log, execute:\n qemu-img check -r "

+                             "all '%s'",

+                             bs->filename, bs->filename);

+            goto exit;

+        }

         /* now flush the log */

         ret = vhdx_log_flush(bs, s, &logs);

         if (ret < 0) {

diff --git a/block/vhdx.c b/block/vhdx.c

index 8e3b371..8b1a5c9 100644

--- a/block/vhdx.c

+++ b/block/vhdx.c

@@ -878,7 +878,6 @@ static int vhdx_open(BlockDriverState *bs, QDict *options, int flags,

     int ret = 0;

     uint32_t i;

     uint64_t signature;

-    bool log_flushed = false;

     s->bat = NULL;

@@ -907,7 +906,7 @@ static int vhdx_open(BlockDriverState *bs, QDict *options, int flags,

         goto fail;

     }

-    ret = vhdx_parse_log(bs, s, &log_flushed);

+    ret = vhdx_parse_log(bs, s, &s->log_replayed_on_open, errp);

     if (ret < 0) {

         goto fail;

     }

@@ -1854,6 +1853,24 @@ exit:

     return ret;

 }

+/* If opened r/w, the VHDX driver will automatically replay the log,

+ * if one is present, inside the vhdx_open() call.

+ *

+ * If qemu-img check -r all is called, the image is automatically opened

+ * r/w and any log has already been replayed, so there is nothing (currently)

+ * for us to do here

+ */

+static int vhdx_check(BlockDriverState *bs, BdrvCheckResult *result,

+                       BdrvCheckMode fix)

+{

+    BDRVVHDXState *s = bs->opaque;

+

+    if (s->log_replayed_on_open) {

+        result->corruptions_fixed++;

+    }

+    return 0;

+}

+

 static QEMUOptionParameter vhdx_create_options[] = {

     {

         .name = BLOCK_OPT_SIZE,

@@ -1896,8 +1913,10 @@ static BlockDriver bdrv_vhdx = {

     .bdrv_reopen_prepare    = vhdx_reopen_prepare,

     .bdrv_co_readv          = vhdx_co_readv,

     .bdrv_co_writev         = vhdx_co_writev,

-    .bdrv_get_info          = vhdx_get_info,

     .bdrv_create            = vhdx_create,

+    .bdrv_get_info          = vhdx_get_info,

+    .bdrv_check             = vhdx_check,

+

     .create_options         = vhdx_create_options,

 };

diff --git a/block/vhdx.h b/block/vhdx.h

index 365eca0..469e95c 100644

--- a/block/vhdx.h

+++ b/block/vhdx.h

@@ -394,6 +394,8 @@ typedef struct BDRVVHDXState {

     Error *migration_blocker;

+    bool log_replayed_on_open;

+

     QLIST_HEAD(VHDXRegionHead, VHDXRegionEntry) regions;

 } BDRVVHDXState;

@@ -408,7 +410,8 @@ uint32_t vhdx_checksum_calc(uint32_t crc, uint8_t *buf, size_t size,

 bool vhdx_checksum_is_valid(uint8_t *buf, size_t size, int crc_offset);

-int vhdx_parse_log(BlockDriverState *bs, BDRVVHDXState *s, bool *flushed);

+int vhdx_parse_log(BlockDriverState *bs, BDRVVHDXState *s, bool *flushed,

+                   Error **errp);

 int vhdx_log_write_and_flush(BlockDriverState *bs, BDRVVHDXState *s,

                              void *data, uint32_t length, uint64_t offset);

-- 

1.7.1