From b882148654e7d9479a7bc05e6b787bc4e9457b0b Mon Sep 17 00:00:00 2001
From: Kevin Wolf <kwolf@redhat.com>
Date: Tue, 6 Jul 2010 09:51:54 -0300
Subject: [PATCH 18/18] qcow2: Use bdrv_(p)write_sync for metadata writes

RH-Author: Kevin Wolf <kwolf@redhat.com>
Message-id: <1278409914-12193-3-git-send-email-kwolf@redhat.com>
Patchwork-id: 10493
O-Subject: [RHEL-5.5.z KVM PATCH v3 2/2] qcow2: Use bdrv_(p)write_sync for
	metadata writes
Bugzilla: 612507
RH-Acked-by: Juan Quintela <quintela@redhat.com>
RH-Acked-by: Christoph Hellwig <chellwig@redhat.com>
RH-Acked-by: Jes Sorensen <Jes.Sorensen@redhat.com>

Bugzilla: 572825
Upstream status: 8b3b7206 is the upstream equivalent

Use bdrv_(p)write_sync to ensure metadata integrity in case of a crash.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 qemu/block-qcow2.c |   70 ++++++++++++++++++++++++++--------------------------
 1 files changed, 35 insertions(+), 35 deletions(-)

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
---
 qemu/block-qcow2.c |   70 ++++++++++++++++++++++++++--------------------------
 1 files changed, 35 insertions(+), 35 deletions(-)

diff --git a/qemu/block-qcow2.c b/qemu/block-qcow2.c
index 5306a50..5647350 100644
--- a/qemu/block-qcow2.c
+++ b/qemu/block-qcow2.c
@@ -500,7 +500,7 @@ static int copy_sectors(BlockDriverState *bs, uint64_t start_sect,
                         s->cluster_data, n, 1,
                         &s->aes_encrypt_cipher);
     }
-    ret = bdrv_write(s->hd, (cluster_offset >> 9) + n_start,
+    ret = bdrv_write_sync(s->hd, (cluster_offset >> 9) + n_start,
                      s->cluster_data, n);
     if (ret < 0)
         return ret;
@@ -567,8 +567,9 @@ static int grow_l1_table(BlockDriverState *bs, int min_size)
 
     for(i = 0; i < s->l1_size; i++)
         new_l1_table[i] = cpu_to_be64(new_l1_table[i]);
-    ret = bdrv_pwrite(s->hd, new_l1_table_offset, new_l1_table, new_l1_size2);
-    if (ret != new_l1_size2)
+    ret = bdrv_pwrite_sync(s->hd, new_l1_table_offset, new_l1_table,
+        new_l1_size2);
+    if (ret < 0)
         goto fail;
     for(i = 0; i < s->l1_size; i++)
         new_l1_table[i] = be64_to_cpu(new_l1_table[i]);
@@ -576,8 +577,9 @@ static int grow_l1_table(BlockDriverState *bs, int min_size)
     /* set new table */
     cpu_to_be32w((uint32_t*)data, new_l1_size);
     cpu_to_be64w((uint64_t*)(data + 4), new_l1_table_offset);
-    ret = bdrv_pwrite(s->hd, offsetof(QCowHeader, l1_size), data,sizeof(data));
-    if (ret != sizeof(data)) {
+    ret = bdrv_pwrite_sync(s->hd, offsetof(QCowHeader, l1_size), data,
+        sizeof(data));
+    if (ret < 0) {
         goto fail;
     }
     qemu_free(s->l1_table);
@@ -678,7 +680,7 @@ static int write_l1_entry(BDRVQcowState *s, int l1_index)
         buf[i] = cpu_to_be64(s->l1_table[l1_start_index + i]);
     }
 
-    ret = bdrv_pwrite(s->hd, s->l1_table_offset + 8 * l1_start_index,
+    ret = bdrv_pwrite_sync(s->hd, s->l1_table_offset + 8 * l1_start_index,
         buf, sizeof(buf));
     if (ret < 0) {
         return ret;
@@ -732,7 +734,7 @@ static int l2_allocate(BlockDriverState *bs, int l1_index, uint64_t **table)
         }
     }
     /* write the l2 table to the file */
-    ret = bdrv_pwrite(s->hd, l2_offset, l2_table,
+    ret = bdrv_pwrite_sync(s->hd, l2_offset, l2_table,
         s->l2_size * sizeof(uint64_t));
     if (ret < 0) {
         goto fail;
@@ -1025,10 +1027,10 @@ static uint64_t alloc_compressed_cluster_offset(BlockDriverState *bs,
     /* compressed clusters never have the copied flag */
 
     l2_table[l2_index] = cpu_to_be64(cluster_offset);
-    if (bdrv_pwrite(s->hd,
+    if (bdrv_pwrite_sync(s->hd,
                     l2_offset + l2_index * sizeof(uint64_t),
                     l2_table + l2_index,
-                    sizeof(uint64_t)) != sizeof(uint64_t))
+                    sizeof(uint64_t)) < 0)
         return 0;
 
     return cluster_offset;
@@ -1057,7 +1059,7 @@ static int write_l2_entries(BDRVQcowState *s, uint64_t *l2_table,
     size_t len = end_offset - start_offset;
     int ret;
 
-    ret = bdrv_pwrite(s->hd, l2_offset + start_offset,
+    ret = bdrv_pwrite_sync(s->hd, l2_offset + start_offset,
         &l2_table[l2_start_index], len);
     if (ret < 0) {
         return ret;
@@ -1748,7 +1750,7 @@ static int qcow2_update_ext_header(BlockDriverState *bs,
         backing_file_offset = sizeof(QCowHeader) + offset;
     }
 
-    ret = bdrv_pwrite(s->hd, sizeof(QCowHeader), buf, ext_size);
+    ret = bdrv_pwrite_sync(s->hd, sizeof(QCowHeader), buf, ext_size);
     if (ret < 0) {
         goto fail;
     }
@@ -1757,13 +1759,13 @@ static int qcow2_update_ext_header(BlockDriverState *bs,
     uint64_t be_backing_file_offset = cpu_to_be64(backing_file_offset);
     uint32_t be_backing_file_size = cpu_to_be32(backing_file_len);
 
-    ret = bdrv_pwrite(s->hd, offsetof(QCowHeader, backing_file_offset),
+    ret = bdrv_pwrite_sync(s->hd, offsetof(QCowHeader, backing_file_offset),
         &be_backing_file_offset, sizeof(uint64_t));
     if (ret < 0) {
         goto fail;
     }
 
-    ret = bdrv_pwrite(s->hd, offsetof(QCowHeader, backing_file_size),
+    ret = bdrv_pwrite_sync(s->hd, offsetof(QCowHeader, backing_file_size),
         &be_backing_file_size, sizeof(uint32_t));
     if (ret < 0) {
         goto fail;
@@ -2134,8 +2136,7 @@ static int update_snapshot_refcount(BlockDriverState *bs,
                 }
             }
             if (l2_modified) {
-                if (bdrv_pwrite(s->hd,
-                                l2_offset, l2_table, l2_size) != l2_size)
+                if (bdrv_pwrite_sync(s->hd, l2_offset, l2_table, l2_size) < 0)
                     goto fail;
             }
 
@@ -2158,8 +2159,8 @@ static int update_snapshot_refcount(BlockDriverState *bs,
     if (l1_modified) {
         for(i = 0; i < l1_size; i++)
             cpu_to_be64s(&l1_table[i]);
-        if (bdrv_pwrite(s->hd, l1_table_offset, l1_table,
-                        l1_size2) != l1_size2)
+        if (bdrv_pwrite_sync(s->hd, l1_table_offset, l1_table,
+                        l1_size2) < 0)
             goto fail;
         for(i = 0; i < l1_size; i++)
             be64_to_cpus(&l1_table[i]);
@@ -2287,25 +2288,25 @@ static int qcow_write_snapshots(BlockDriverState *bs)
         h.id_str_size = cpu_to_be16(id_str_size);
         h.name_size = cpu_to_be16(name_size);
         offset = align_offset(offset, 8);
-        if (bdrv_pwrite(s->hd, offset, &h, sizeof(h)) != sizeof(h))
+        if (bdrv_pwrite_sync(s->hd, offset, &h, sizeof(h)) < 0)
             goto fail;
         offset += sizeof(h);
-        if (bdrv_pwrite(s->hd, offset, sn->id_str, id_str_size) != id_str_size)
+        if (bdrv_pwrite_sync(s->hd, offset, sn->id_str, id_str_size) < 0)
             goto fail;
         offset += id_str_size;
-        if (bdrv_pwrite(s->hd, offset, sn->name, name_size) != name_size)
+        if (bdrv_pwrite_sync(s->hd, offset, sn->name, name_size) < 0)
             goto fail;
         offset += name_size;
     }
 
     /* update the various header fields */
     data64 = cpu_to_be64(snapshots_offset);
-    if (bdrv_pwrite(s->hd, offsetof(QCowHeader, snapshots_offset),
-                    &data64, sizeof(data64)) != sizeof(data64))
+    if (bdrv_pwrite_sync(s->hd, offsetof(QCowHeader, snapshots_offset),
+                    &data64, sizeof(data64)) < 0)
         goto fail;
     data32 = cpu_to_be32(s->nb_snapshots);
-    if (bdrv_pwrite(s->hd, offsetof(QCowHeader, nb_snapshots),
-                    &data32, sizeof(data32)) != sizeof(data32))
+    if (bdrv_pwrite_sync(s->hd, offsetof(QCowHeader, nb_snapshots),
+                    &data32, sizeof(data32)) < 0)
         goto fail;
 
     /* free the old snapshot table */
@@ -2411,9 +2412,8 @@ static int qcow_snapshot_create(BlockDriverState *bs,
     for(i = 0; i < s->l1_size; i++) {
         l1_table[i] = cpu_to_be64(s->l1_table[i]);
     }
-    if (bdrv_pwrite(s->hd, sn->l1_table_offset,
-                    l1_table, s->l1_size * sizeof(uint64_t)) !=
-        (s->l1_size * sizeof(uint64_t)))
+    if (bdrv_pwrite_sync(s->hd, sn->l1_table_offset,
+                    l1_table, s->l1_size * sizeof(uint64_t)) < 0)
         goto fail;
     qemu_free(l1_table);
     l1_table = NULL;
@@ -2463,8 +2463,8 @@ static int qcow_snapshot_goto(BlockDriverState *bs,
     if (bdrv_pread(s->hd, sn->l1_table_offset,
                    s->l1_table, l1_size2) != l1_size2)
         goto fail;
-    if (bdrv_pwrite(s->hd, s->l1_table_offset,
-                    s->l1_table, l1_size2) != l1_size2)
+    if (bdrv_pwrite_sync(s->hd, s->l1_table_offset,
+                    s->l1_table, l1_size2) < 0)
         goto fail;
     for(i = 0;i < s->l1_size; i++) {
         be64_to_cpus(&s->l1_table[i]);
@@ -2863,7 +2863,7 @@ static int64_t alloc_refcount_block(BlockDriverState *bs, int64_t cluster_index)
     }
 
     /* Now the new refcount block needs to be written to disk */
-    ret = bdrv_pwrite(s->hd, new_block, s->refcount_block_cache,
+    ret = bdrv_pwrite_sync(s->hd, new_block, s->refcount_block_cache,
         s->cluster_size);
     if (ret < 0) {
         goto fail_block;
@@ -2872,7 +2872,7 @@ static int64_t alloc_refcount_block(BlockDriverState *bs, int64_t cluster_index)
     /* If the refcount table is big enough, just hook the block up there */
     if (refcount_table_index < s->refcount_table_size) {
         uint64_t data64 = cpu_to_be64(new_block);
-        ret = bdrv_pwrite(s->hd,
+        ret = bdrv_pwrite_sync(s->hd,
             s->refcount_table_offset + refcount_table_index * sizeof(uint64_t),
             &data64, sizeof(data64));
         if (ret < 0) {
@@ -2949,7 +2949,7 @@ static int64_t alloc_refcount_block(BlockDriverState *bs, int64_t cluster_index)
     }
 
     /* Write refcount blocks to disk */
-    ret = bdrv_pwrite(s->hd, meta_offset, new_blocks,
+    ret = bdrv_pwrite_sync(s->hd, meta_offset, new_blocks,
         blocks_clusters * s->cluster_size);
     qemu_free(new_blocks);
     if (ret < 0) {
@@ -2961,7 +2961,7 @@ static int64_t alloc_refcount_block(BlockDriverState *bs, int64_t cluster_index)
         cpu_to_be64s(&new_table[i]);
     }
 
-    ret = bdrv_pwrite(s->hd, table_offset, new_table,
+    ret = bdrv_pwrite_sync(s->hd, table_offset, new_table,
         table_size * sizeof(uint64_t));
     if (ret < 0) {
         goto fail_table;
@@ -2975,7 +2975,7 @@ static int64_t alloc_refcount_block(BlockDriverState *bs, int64_t cluster_index)
     uint8_t data[12];
     cpu_to_be64w((uint64_t*)data, table_offset);
     cpu_to_be32w((uint32_t*)(data + 8), table_clusters);
-    ret = bdrv_pwrite(s->hd, offsetof(QCowHeader, refcount_table_offset),
+    ret = bdrv_pwrite_sync(s->hd, offsetof(QCowHeader, refcount_table_offset),
         data, sizeof(data));
     if (ret < 0) {
         goto fail_table;
@@ -3048,7 +3048,7 @@ static int write_refcount_block_entries(BDRVQcowState *s,
 
     size = (last_index - first_index) << REFCOUNT_SHIFT;
 
-    ret = bdrv_pwrite(s->hd,
+    ret = bdrv_pwrite_sync(s->hd,
         refcount_block_offset + (first_index << REFCOUNT_SHIFT),
         &s->refcount_block_cache[first_index], size);
     if (ret < 0) {
-- 
1.7.0.3