From c310637234eeafe32d0eb5626f91e12b5a2399b9 Mon Sep 17 00:00:00 2001

From: Jeffrey Cody <jcody@redhat.com>

Date: Wed, 20 Nov 2013 19:43:55 +0100

Subject: [PATCH 12/25] block: vhdx - update log guid in header, and first write tracker

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

Message-id: <313d521b2aab6f6657de5b4fbb9cc10e58d9d5c4.1384975172.git.jcody@redhat.com>

Patchwork-id: 55806

O-Subject: [RHEL7 qemu-kvm PATCH 12/26] block: vhdx - update log guid in header, and first write tracker

Bugzilla: 879234

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

RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>

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

Allow tracking of first file write in the VHDX image, as well as

the ability to update the GUID in the header.  This is in preparation

for log support.

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

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

(cherry picked from commit c3906c5e8281b37a526c706596af8575d6ac00d3)

---

 block/vhdx.c | 30 ++++++++++++++++++++++++------

 block/vhdx.h |  6 ++++++

 2 files changed, 30 insertions(+), 6 deletions(-)

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

---

 block/vhdx.c |   30 ++++++++++++++++++++++++------

 block/vhdx.h |    6 ++++++

 2 files changed, 30 insertions(+), 6 deletions(-)

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

index 2efece1..49219df 100644

--- a/block/vhdx.c

+++ b/block/vhdx.c

@@ -230,7 +230,7 @@ static int vhdx_probe(const uint8_t *buf, int buf_size, const char *filename)

  *  - non-current header is updated with largest sequence number

  */

 static int vhdx_update_header(BlockDriverState *bs, BDRVVHDXState *s,

-                              bool generate_data_write_guid)

+                              bool generate_data_write_guid, MSGUID *log_guid)

 {

     int ret = 0;

     int hdr_idx = 0;

@@ -262,6 +262,11 @@ static int vhdx_update_header(BlockDriverState *bs, BDRVVHDXState *s,

         vhdx_guid_generate(&inactive_header->data_write_guid);

     }

+    /* update the log guid if present */

+    if (log_guid) {

+        inactive_header->log_guid = *log_guid;

+    }

+

     /* the header checksum is not over just the packed size of VHDXHeader,

      * but rather over the entire 'reserved' range for the header, which is

      * 4KB (VHDX_HEADER_SIZE). */

@@ -294,16 +299,16 @@ exit:

  * The VHDX spec calls for header updates to be performed twice, so that both

  * the current and non-current header have valid info

  */

-static int vhdx_update_headers(BlockDriverState *bs, BDRVVHDXState *s,

-                               bool generate_data_write_guid)

+int vhdx_update_headers(BlockDriverState *bs, BDRVVHDXState *s,

+                        bool generate_data_write_guid, MSGUID *log_guid)

 {

     int ret;

-    ret = vhdx_update_header(bs, s, generate_data_write_guid);

+    ret = vhdx_update_header(bs, s, generate_data_write_guid, log_guid);

     if (ret < 0) {

         return ret;

     }

-    ret = vhdx_update_header(bs, s, generate_data_write_guid);

+    ret = vhdx_update_header(bs, s, generate_data_write_guid, log_guid);

     return ret;

 }

@@ -784,6 +789,7 @@ static int vhdx_open(BlockDriverState *bs, QDict *options, int flags,

     s->bat = NULL;

+    s->first_visible_write = true;

     qemu_co_mutex_init(&s->lock);

@@ -864,7 +870,7 @@ static int vhdx_open(BlockDriverState *bs, QDict *options, int flags,

     }

     if (flags & BDRV_O_RDWR) {

-        ret = vhdx_update_headers(bs, s, false);

+        ret = vhdx_update_headers(bs, s, false, NULL);

         if (ret < 0) {

             goto fail;

         }

@@ -1022,6 +1028,18 @@ exit:

+/* Per the spec, on the first write of guest-visible data to the file the

+ * data write guid must be updated in the header */

+int vhdx_user_visible_write(BlockDriverState *bs, BDRVVHDXState *s)

+{

+    int ret = 0;

+    if (s->first_visible_write) {

+        s->first_visible_write = false;

+        ret = vhdx_update_headers(bs, s, true, NULL);

+    }

+    return ret;

+}

+

 static coroutine_fn int vhdx_co_writev(BlockDriverState *bs, int64_t sector_num,

                                       int nb_sectors, QEMUIOVector *qiov)

 {

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

index 55975a2..81785e5 100644

--- a/block/vhdx.h

+++ b/block/vhdx.h

@@ -361,6 +361,7 @@ typedef struct BDRVVHDXState {

     VHDXBatEntry *bat;

     uint64_t bat_offset;

+    bool first_visible_write;

     MSGUID session_guid;

     VHDXLogEntries log;

@@ -373,6 +374,9 @@ typedef struct BDRVVHDXState {

 void vhdx_guid_generate(MSGUID *guid);

+int vhdx_update_headers(BlockDriverState *bs, BDRVVHDXState *s, bool rw,

+                        MSGUID *log_guid);

+

 uint32_t vhdx_update_checksum(uint8_t *buf, size_t size, int crc_offset);

 uint32_t vhdx_checksum_calc(uint32_t crc, uint8_t *buf, size_t size,

                             int crc_offset);

@@ -402,4 +406,6 @@ void vhdx_log_data_le_export(VHDXLogDataSector *d);

 void vhdx_log_entry_hdr_le_import(VHDXLogEntryHeader *hdr);

 void vhdx_log_entry_hdr_le_export(VHDXLogEntryHeader *hdr);

+int vhdx_user_visible_write(BlockDriverState *bs, BDRVVHDXState *s);

+

 #endif

-- 

1.7.1