From ca635f6c3ae10562a2165590bb84667aa61ad12f Mon Sep 17 00:00:00 2001

From: Max Reitz <mreitz@redhat.com>

Date: Mon, 4 Nov 2013 22:32:29 +0100

Subject: [PATCH 36/87] qcow2: Use negated overflow check mask

RH-Author: Max Reitz <mreitz@redhat.com>

Message-id: <1383604354-12743-39-git-send-email-mreitz@redhat.com>

Patchwork-id: 55338

O-Subject: [RHEL-7.0 qemu-kvm PATCH 38/43] qcow2: Use negated overflow check mask

Bugzilla: 1004347

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

RH-Acked-by: Laszlo Ersek <lersek@redhat.com>

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

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

BZ: 1004347

In qcow2_check_metadata_overlap and qcow2_pre_write_overlap_check,

change the parameter signifying the checks to perform from its current

positive form to a negative one, i.e., it will no longer explicitly

specify every check to perform but rather a mask of checks not to

perform.

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

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

(cherry picked from commit 231bb267644ee3a9ebfd9c7f42d5d41610194b45)

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

Conflicts:

	block/qcow2-cluster.c

Conflicts because downstream does not contain

expand_zero_clusters_in_l1().

---

 block/qcow2-cache.c    |  8 +++-----

 block/qcow2-cluster.c  |  9 ++++-----

 block/qcow2-refcount.c | 22 ++++++++++------------

 block/qcow2-snapshot.c | 12 +++++-------

 block/qcow2.c          |  5 ++---

 block/qcow2.h          |  4 ++--

 6 files changed, 26 insertions(+), 34 deletions(-)

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

---

 block/qcow2-cache.c    |    8 +++-----

 block/qcow2-cluster.c  |    9 ++++-----

 block/qcow2-refcount.c |   22 ++++++++++------------

 block/qcow2-snapshot.c |   12 +++++-------

 block/qcow2.c          |    5 ++---

 block/qcow2.h          |    4 ++--

 6 files changed, 26 insertions(+), 34 deletions(-)

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

index 7bcae09..eb1d69b 100644

--- a/block/qcow2-cache.c

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

@@ -115,15 +115,13 @@ static int qcow2_cache_entry_flush(BlockDriverState *bs, Qcow2Cache *c, int i)

     }

     if (c == s->refcount_block_cache) {

-        ret = qcow2_pre_write_overlap_check(bs,

-                QCOW2_OL_DEFAULT & ~QCOW2_OL_REFCOUNT_BLOCK,

+        ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_REFCOUNT_BLOCK,

                 c->entries[i].offset, s->cluster_size);

     } else if (c == s->l2_table_cache) {

-        ret = qcow2_pre_write_overlap_check(bs,

-                QCOW2_OL_DEFAULT & ~QCOW2_OL_ACTIVE_L2,

+        ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_ACTIVE_L2,

                 c->entries[i].offset, s->cluster_size);

     } else {

-        ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_DEFAULT,

+        ret = qcow2_pre_write_overlap_check(bs, 0,

                 c->entries[i].offset, s->cluster_size);

     }

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

index c05f182..5d13515 100644

--- a/block/qcow2-cluster.c

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

@@ -83,8 +83,8 @@ int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t min_size,

     /* the L1 position has not yet been updated, so these clusters must

      * indeed be completely free */

-    ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_DEFAULT,

-                                        new_l1_table_offset, new_l1_size2);

+    ret = qcow2_pre_write_overlap_check(bs, 0, new_l1_table_offset,

+                                        new_l1_size2);

     if (ret < 0) {

         goto fail;

     }

@@ -160,8 +160,7 @@ int qcow2_write_l1_entry(BlockDriverState *bs, int l1_index)

         buf[i] = cpu_to_be64(s->l1_table[l1_start_index + i]);

     }

-    ret = qcow2_pre_write_overlap_check(bs,

-            QCOW2_OL_DEFAULT & ~QCOW2_OL_ACTIVE_L1,

+    ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_ACTIVE_L1,

             s->l1_table_offset + 8 * l1_start_index, sizeof(buf));

     if (ret < 0) {

         return ret;

@@ -386,7 +385,7 @@ static int coroutine_fn copy_sectors(BlockDriverState *bs,

                         &s->aes_encrypt_key);

     }

-    ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_DEFAULT,

+    ret = qcow2_pre_write_overlap_check(bs, 0,

             cluster_offset + n_start * BDRV_SECTOR_SIZE, n * BDRV_SECTOR_SIZE);

     if (ret < 0) {

         goto out;

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

index 5c5683d..91c446b 100644

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

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

@@ -1291,9 +1291,8 @@ static int check_oflag_copied(BlockDriverState *bs, BdrvCheckResult *res,

         }

         if (l2_dirty) {

-            ret = qcow2_pre_write_overlap_check(bs,

-                    QCOW2_OL_DEFAULT & ~QCOW2_OL_ACTIVE_L2, l2_offset,

-                    s->cluster_size);

+            ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_ACTIVE_L2,

+                                                l2_offset, s->cluster_size);

             if (ret < 0) {

                 fprintf(stderr, "ERROR: Could not write L2 table; metadata "

                         "overlap check failed: %s\n", strerror(-ret));

@@ -1334,8 +1333,7 @@ static int write_reftable_entry(BlockDriverState *bs, int rt_index)

         buf[i] = cpu_to_be64(s->refcount_table[rt_start_index + i]);

     }

-    ret = qcow2_pre_write_overlap_check(bs,

-            QCOW2_OL_DEFAULT & ~QCOW2_OL_REFCOUNT_TABLE,

+    ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_REFCOUNT_TABLE,

             s->refcount_table_offset + rt_start_index * sizeof(uint64_t),

             sizeof(buf));

     if (ret < 0) {

@@ -1386,8 +1384,7 @@ static int64_t realloc_refcount_block(BlockDriverState *bs, int reftable_index,

     /* new block has not yet been entered into refcount table, therefore it is

      * no refcount block yet (regarding this check) */

-    ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_DEFAULT, new_offset,

-            s->cluster_size);

+    ret = qcow2_pre_write_overlap_check(bs, 0, new_offset, s->cluster_size);

     if (ret < 0) {

         fprintf(stderr, "Could not write refcount block; metadata overlap "

                 "check failed: %s\n", strerror(-ret));

@@ -1619,8 +1616,8 @@ fail:

  * looking for overlaps with important metadata sections (L1/L2 tables etc.),

  * i.e. a sanity check without relying on the refcount tables.

  *

- * The chk parameter specifies exactly what checks to perform (being a bitmask

- * of QCow2MetadataOverlap values).

+ * The ign parameter specifies what checks not to perform (being a bitmask of

+ * QCow2MetadataOverlap values), i.e., what sections to ignore.

  *

  * Returns:

  * - 0 if writing to this offset will not affect the mentioned metadata

@@ -1628,10 +1625,11 @@ fail:

  * - a negative value (-errno) indicating an error while performing a check,

  *   e.g. when bdrv_read failed on QCOW2_OL_INACTIVE_L2

  */

-int qcow2_check_metadata_overlap(BlockDriverState *bs, int chk, int64_t offset,

+int qcow2_check_metadata_overlap(BlockDriverState *bs, int ign, int64_t offset,

                                  int64_t size)

 {

     BDRVQcowState *s = bs->opaque;

+    int chk = QCOW2_OL_DEFAULT & ~ign;

     int i, j;

     if (!size) {

@@ -1747,10 +1745,10 @@ static const char *metadata_ol_names[] = {

  * Returns 0 if there were neither overlaps nor errors while checking for

  * overlaps; or a negative value (-errno) on error.

  */

-int qcow2_pre_write_overlap_check(BlockDriverState *bs, int chk, int64_t offset,

+int qcow2_pre_write_overlap_check(BlockDriverState *bs, int ign, int64_t offset,

                                   int64_t size)

 {

-    int ret = qcow2_check_metadata_overlap(bs, chk, offset, size);

+    int ret = qcow2_check_metadata_overlap(bs, ign, offset, size);

     if (ret < 0) {

         return ret;

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

index 450e4f5..aa88c51 100644

--- a/block/qcow2-snapshot.c

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

@@ -191,8 +191,7 @@ static int qcow2_write_snapshots(BlockDriverState *bs)

     /* The snapshot list position has not yet been updated, so these clusters

      * must indeed be completely free */

-    ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_DEFAULT, offset,

-                                        snapshots_size);

+    ret = qcow2_pre_write_overlap_check(bs, 0, offset, snapshots_size);

     if (ret < 0) {

         return ret;

     }

@@ -372,8 +371,8 @@ int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info)

         l1_table[i] = cpu_to_be64(s->l1_table[i]);

     }

-    ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_DEFAULT,

-            sn->l1_table_offset, s->l1_size * sizeof(uint64_t));

+    ret = qcow2_pre_write_overlap_check(bs, 0, sn->l1_table_offset,

+                                        s->l1_size * sizeof(uint64_t));

     if (ret < 0) {

         goto fail;

     }

@@ -490,9 +489,8 @@ int qcow2_snapshot_goto(BlockDriverState *bs, const char *snapshot_id)

         goto fail;

     }

-    ret = qcow2_pre_write_overlap_check(bs,

-            QCOW2_OL_DEFAULT & ~QCOW2_OL_ACTIVE_L1,

-            s->l1_table_offset, cur_l1_bytes);

+    ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_ACTIVE_L1,

+                                        s->l1_table_offset, cur_l1_bytes);

     if (ret < 0) {

         goto fail;

     }

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

index 8b73518..ac5ed47 100644

--- a/block/qcow2.c

+++ b/block/qcow2.c

@@ -964,7 +964,7 @@ static coroutine_fn int qcow2_co_writev(BlockDriverState *bs,

                 cur_nr_sectors * 512);

         }

-        ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_DEFAULT,

+        ret = qcow2_pre_write_overlap_check(bs, 0,

                 cluster_offset + index_in_cluster * BDRV_SECTOR_SIZE,

                 cur_nr_sectors * BDRV_SECTOR_SIZE);

         if (ret < 0) {

@@ -1748,8 +1748,7 @@ static int qcow2_write_compressed(BlockDriverState *bs, int64_t sector_num,

         }

         cluster_offset &= s->cluster_offset_mask;

-        ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_DEFAULT,

-                cluster_offset, out_len);

+        ret = qcow2_pre_write_overlap_check(bs, 0, cluster_offset, out_len);

         if (ret < 0) {

             goto fail;

         }

diff --git a/block/qcow2.h b/block/qcow2.h

index 10b7bf4..64ad43c 100644

--- a/block/qcow2.h

+++ b/block/qcow2.h

@@ -424,9 +424,9 @@ int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res,

 void qcow2_process_discards(BlockDriverState *bs, int ret);

-int qcow2_check_metadata_overlap(BlockDriverState *bs, int chk, int64_t offset,

+int qcow2_check_metadata_overlap(BlockDriverState *bs, int ign, int64_t offset,

                                  int64_t size);

-int qcow2_pre_write_overlap_check(BlockDriverState *bs, int chk, int64_t offset,

+int qcow2_pre_write_overlap_check(BlockDriverState *bs, int ign, int64_t offset,

                                   int64_t size);

 /* qcow2-cluster.c functions */

-- 

1.7.1