From f9a81072210afed390c21465ba973fc557105b79 Mon Sep 17 00:00:00 2001

From: Max Reitz <mreitz@redhat.com>

Date: Sat, 13 Jun 2015 16:22:18 +0200

Subject: [PATCH 24/42] qcow2: Let inc_refcounts() resize the reftable

Message-id: <1434212556-3927-25-git-send-email-mreitz@redhat.com>

Patchwork-id: 66043

O-Subject: [RHEL-7.2 qemu-kvm PATCH 24/42] qcow2: Let inc_refcounts() resize the reftable

Bugzilla: 1129893

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

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

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

BZ: 1129893

Now that the refcount table can be passed around by reference, do that

for inc_refcounts() (and subsequently check_refcounts_l1() and

check_refcounts_l2()) and use it for resizing it when a cluster after

the image end is encountered.

Signed-off-by: Max Reitz <mreitz@redhat.com>

Signed-off-by: Kevin Wolf <kwolf@redhat.com>

(cherry picked from commit 641bb63cd6b003ab0ca2e312a014449037d71647)

Signed-off-by: Max Reitz <mreitz@redhat.com>

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

---

 block/qcow2-refcount.c | 57 +++++++++++++++++++++++++++++++-------------------

 1 file changed, 35 insertions(+), 22 deletions(-)

diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c

index 4655fa2..7d03e65 100644

--- a/block/qcow2-refcount.c

+++ b/block/qcow2-refcount.c

@@ -1055,8 +1055,8 @@ fail:

  */

 static int inc_refcounts(BlockDriverState *bs,

                          BdrvCheckResult *res,

-                         uint16_t *refcount_table,

-                         int64_t refcount_table_size,

+                         uint16_t **refcount_table,

+                         int64_t *refcount_table_size,

                          int64_t offset, int64_t size)

 {

     BDRVQcowState *s = bs->opaque;

@@ -1071,17 +1071,30 @@ static int inc_refcounts(BlockDriverState *bs,

     for(cluster_offset = start; cluster_offset <= last;

         cluster_offset += s->cluster_size) {

         k = cluster_offset >> s->cluster_bits;

-        if (k >= refcount_table_size) {

-            fprintf(stderr, "Warning: cluster offset=0x%" PRIx64 " is after "

-                "the end of the image file, can't properly check refcounts.\n",

-                cluster_offset);

-            res->check_errors++;

-        } else {

-            if (++refcount_table[k] == 0) {

-                fprintf(stderr, "ERROR: overflow cluster offset=0x%" PRIx64

-                    "\n", cluster_offset);

-                res->corruptions++;

+        if (k >= *refcount_table_size) {

+            int64_t old_refcount_table_size = *refcount_table_size;

+            uint16_t *new_refcount_table;

+

+            *refcount_table_size = k + 1;

+            new_refcount_table = g_try_realloc(*refcount_table,

+                                               *refcount_table_size *

+                                               sizeof(**refcount_table));

+            if (!new_refcount_table) {

+                *refcount_table_size = old_refcount_table_size;

+                res->check_errors++;

+                return -ENOMEM;

             }

+            *refcount_table = new_refcount_table;

+

+            memset(*refcount_table + old_refcount_table_size, 0,

+                   (*refcount_table_size - old_refcount_table_size) *

+                   sizeof(**refcount_table));

+        }

+

+        if (++(*refcount_table)[k] == 0) {

+            fprintf(stderr, "ERROR: overflow cluster offset=0x%" PRIx64

+                    "\n", cluster_offset);

+            res->corruptions++;

         }

     }

@@ -1102,7 +1115,7 @@ enum {

  * error occurred.

  */

 static int check_refcounts_l2(BlockDriverState *bs, BdrvCheckResult *res,

-    uint16_t *refcount_table, int64_t refcount_table_size, int64_t l2_offset,

+    uint16_t **refcount_table, int64_t *refcount_table_size, int64_t l2_offset,

     int flags)

 {

     BDRVQcowState *s = bs->opaque;

@@ -1220,8 +1233,8 @@ fail:

  */

 static int check_refcounts_l1(BlockDriverState *bs,

                               BdrvCheckResult *res,

-                              uint16_t *refcount_table,

-                              int64_t refcount_table_size,

+                              uint16_t **refcount_table,

+                              int64_t *refcount_table_size,

                               int64_t l1_table_offset, int l1_size,

                               int flags)

 {

@@ -1556,7 +1569,7 @@ static int check_refblocks(BlockDriverState *bs, BdrvCheckResult *res,

         }

         if (offset != 0) {

-            ret = inc_refcounts(bs, res, *refcount_table, *nb_clusters,

+            ret = inc_refcounts(bs, res, refcount_table, nb_clusters,

                                 offset, s->cluster_size);

             if (ret < 0) {

                 return ret;

@@ -1589,7 +1602,7 @@ static int check_refblocks(BlockDriverState *bs, BdrvCheckResult *res,

                                sizeof(**refcount_table));

                     }

                     (*refcount_table)[cluster]--;

-                    ret = inc_refcounts(bs, res, *refcount_table, *nb_clusters,

+                    ret = inc_refcounts(bs, res, refcount_table, nb_clusters,

                                         new_offset, s->cluster_size);

                     if (ret < 0) {

                         return ret;

@@ -1625,14 +1638,14 @@ static int calculate_refcounts(BlockDriverState *bs, BdrvCheckResult *res,

     }

     /* header */

-    ret = inc_refcounts(bs, res, *refcount_table, *nb_clusters,

+    ret = inc_refcounts(bs, res, refcount_table, nb_clusters,

                         0, s->cluster_size);

     if (ret < 0) {

         return ret;

     }

     /* current L1 table */

-    ret = check_refcounts_l1(bs, res, *refcount_table, *nb_clusters,

+    ret = check_refcounts_l1(bs, res, refcount_table, nb_clusters,

                              s->l1_table_offset, s->l1_size, CHECK_FRAG_INFO);

     if (ret < 0) {

         return ret;

@@ -1641,20 +1654,20 @@ static int calculate_refcounts(BlockDriverState *bs, BdrvCheckResult *res,

     /* snapshots */

     for (i = 0; i < s->nb_snapshots; i++) {

         sn = s->snapshots + i;

-        ret = check_refcounts_l1(bs, res, *refcount_table, *nb_clusters,

+        ret = check_refcounts_l1(bs, res, refcount_table, nb_clusters,

                                  sn->l1_table_offset, sn->l1_size, 0);

         if (ret < 0) {

             return ret;

         }

     }

-    ret = inc_refcounts(bs, res, *refcount_table, *nb_clusters,

+    ret = inc_refcounts(bs, res, refcount_table, nb_clusters,

                         s->snapshots_offset, s->snapshots_size);

     if (ret < 0) {

         return ret;

     }

     /* refcount data */

-    ret = inc_refcounts(bs, res, *refcount_table, *nb_clusters,

+    ret = inc_refcounts(bs, res, refcount_table, nb_clusters,

                         s->refcount_table_offset,

                         s->refcount_table_size * sizeof(uint64_t));

     if (ret < 0) {

-- 

1.8.3.1