From 4816392698b781605104fb55c4b25af788a86788 Mon Sep 17 00:00:00 2001
From: Max Reitz <mreitz@redhat.com>
Date: Fri, 2 May 2014 16:58:41 -0500
Subject: [PATCH 09/26] qcow2-refcount: Move OFLAG_COPIED checks
RH-Author: Max Reitz <mreitz@redhat.com>
Message-id: <1399049936-13496-10-git-send-email-mreitz@redhat.com>
Patchwork-id: 58655
O-Subject: [RHEL-6.6 qemu-kvm PATCH v3 09/24] qcow2-refcount: Move OFLAG_COPIED checks
Bugzilla: 1004420
RH-Acked-by: Laszlo Ersek <lersek@redhat.com>
RH-Acked-by: Kevin Wolf <kwolf@redhat.com>
RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
BZ: 1004420
Move the OFLAG_COPIED checks out of check_refcounts_l1 and
check_refcounts_l2 and after the actual refcount checks/fixes (since the
refcounts might actually change there).
Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
(cherry picked from commit 4f6ed88c03c4026e31ce152ea760a0da839f0dda)
Conflicts:
block/qcow2-refcount.c
Conflicts because there is no zero cluster support downstream (due to
missing compat level 1.1 support) and because the
check_refcounts_l[12]() do not receive a check flag bitmask, but rather
just the check_copied flag (which is made obsolete by this patch).
Signed-off-by: Max Reitz <mreitz@redhat.com>
---
block/qcow2-refcount.c | 128 +++++++++++++++++++++++++++++++++----------------
1 file changed, 86 insertions(+), 42 deletions(-)
Signed-off-by: Jeff E. Nelson <jen@redhat.com>
---
block/qcow2-refcount.c | 128 ++++++++++++++++++++++++++++++++----------------
1 files changed, 86 insertions(+), 42 deletions(-)
diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c
index 5abb196..da7c566 100644
--- a/block/qcow2-refcount.c
+++ b/block/qcow2-refcount.c
@@ -928,12 +928,11 @@ static void inc_refcounts(BlockDriverState *bs,
* error occurred.
*/
static int check_refcounts_l2(BlockDriverState *bs, BdrvCheckResult *res,
- uint16_t *refcount_table, int refcount_table_size, int64_t l2_offset,
- int check_copied)
+ uint16_t *refcount_table, int refcount_table_size, int64_t l2_offset)
{
BDRVQcowState *s = bs->opaque;
uint64_t *l2_table, offset;
- int i, l2_size, nb_csectors, refcount;
+ int i, l2_size, nb_csectors;
/* Read L2 table from disk */
l2_size = s->l2_size * sizeof(uint64_t);
@@ -963,23 +962,6 @@ static int check_refcounts_l2(BlockDriverState *bs, BdrvCheckResult *res,
inc_refcounts(bs, res, refcount_table, refcount_table_size,
offset & ~511, nb_csectors * 512);
} else {
- /* QCOW_OFLAG_COPIED must be set iff refcount == 1 */
- if (check_copied) {
- uint64_t entry = offset;
- offset &= ~QCOW_OFLAG_COPIED;
- refcount = get_refcount(bs, offset >> s->cluster_bits);
- if (refcount < 0) {
- fprintf(stderr, "Can't get refcount for offset %"
- PRIx64 ": %s\n", entry, strerror(-refcount));
- goto fail;
- }
- if ((refcount == 1) != ((entry & QCOW_OFLAG_COPIED) != 0)) {
- fprintf(stderr, "ERROR OFLAG_COPIED: offset=%"
- PRIx64 " refcount=%d\n", entry, refcount);
- res->corruptions++;
- }
- }
-
/* Mark cluster as used */
offset &= ~QCOW_OFLAG_COPIED;
inc_refcounts(bs, res, refcount_table,refcount_table_size,
@@ -1016,12 +998,11 @@ static int check_refcounts_l1(BlockDriverState *bs,
BdrvCheckResult *res,
uint16_t *refcount_table,
int refcount_table_size,
- int64_t l1_table_offset, int l1_size,
- int check_copied)
+ int64_t l1_table_offset, int l1_size)
{
BDRVQcowState *s = bs->opaque;
uint64_t *l1_table, l2_offset, l1_size2;
- int i, refcount, ret;
+ int i, ret;
l1_size2 = l1_size * sizeof(uint64_t);
@@ -1045,22 +1026,6 @@ static int check_refcounts_l1(BlockDriverState *bs,
for(i = 0; i < l1_size; i++) {
l2_offset = l1_table[i];
if (l2_offset) {
- /* QCOW_OFLAG_COPIED must be set iff refcount == 1 */
- if (check_copied) {
- refcount = get_refcount(bs, (l2_offset & ~QCOW_OFLAG_COPIED)
- >> s->cluster_bits);
- if (refcount < 0) {
- fprintf(stderr, "Can't get refcount for l2_offset %"
- PRIx64 ": %s\n", l2_offset, strerror(-refcount));
- goto fail;
- }
- if ((refcount == 1) != ((l2_offset & QCOW_OFLAG_COPIED) != 0)) {
- fprintf(stderr, "ERROR OFLAG_COPIED: l2_offset=%" PRIx64
- " refcount=%d\n", l2_offset, refcount);
- res->corruptions++;
- }
- }
-
/* Mark L2 table as used */
l2_offset &= ~QCOW_OFLAG_COPIED;
inc_refcounts(bs, res, refcount_table, refcount_table_size,
@@ -1075,7 +1040,7 @@ static int check_refcounts_l1(BlockDriverState *bs,
/* Process and check L2 entries */
ret = check_refcounts_l2(bs, res, refcount_table,
- refcount_table_size, l2_offset, check_copied);
+ refcount_table_size, l2_offset);
if (ret < 0) {
goto fail;
}
@@ -1092,6 +1057,79 @@ fail:
}
/*
+ * Checks the OFLAG_COPIED flag for all L1 and L2 entries.
+ *
+ * This function does not print an error message nor does it increment
+ * check_errors if get_refcount fails (this is because such an error will have
+ * been already detected and sufficiently signaled by the calling function
+ * (qcow2_check_refcounts) by the time this function is called).
+ */
+static int check_oflag_copied(BlockDriverState *bs, BdrvCheckResult *res)
+{
+ BDRVQcowState *s = bs->opaque;
+ uint64_t *l2_table = qemu_blockalign(bs, s->cluster_size);
+ int ret;
+ int refcount;
+ int i, j;
+
+ for (i = 0; i < s->l1_size; i++) {
+ uint64_t l1_entry = s->l1_table[i];
+ uint64_t l2_offset = l1_entry & L1E_OFFSET_MASK;
+
+ if (!l2_offset) {
+ continue;
+ }
+
+ refcount = get_refcount(bs, l2_offset >> s->cluster_bits);
+ if (refcount < 0) {
+ /* don't print message nor increment check_errors */
+ continue;
+ }
+ if ((refcount == 1) != ((l1_entry & QCOW_OFLAG_COPIED) != 0)) {
+ fprintf(stderr, "ERROR OFLAG_COPIED L2 cluster: l1_index=%d "
+ "l1_entry=%" PRIx64 " refcount=%d\n",
+ i, l1_entry, refcount);
+ res->corruptions++;
+ }
+
+ ret = bdrv_pread(bs->file, l2_offset, l2_table,
+ s->l2_size * sizeof(uint64_t));
+ if (ret < 0) {
+ fprintf(stderr, "ERROR: Could not read L2 table: %s\n",
+ strerror(-ret));
+ res->check_errors++;
+ goto fail;
+ }
+
+ for (j = 0; j < s->l2_size; j++) {
+ uint64_t l2_entry = be64_to_cpu(l2_table[j]);
+ uint64_t data_offset = l2_entry & L2E_OFFSET_MASK;
+ int cluster_type = qcow2_get_cluster_type(l2_entry);
+
+ if (cluster_type == QCOW2_CLUSTER_NORMAL) {
+ refcount = get_refcount(bs, data_offset >> s->cluster_bits);
+ if (refcount < 0) {
+ /* don't print message nor increment check_errors */
+ continue;
+ }
+ if ((refcount == 1) != ((l2_entry & QCOW_OFLAG_COPIED) != 0)) {
+ fprintf(stderr, "ERROR OFLAG_COPIED data cluster: "
+ "l2_entry=%" PRIx64 " refcount=%d\n",
+ l2_entry, refcount);
+ res->corruptions++;
+ }
+ }
+ }
+ }
+
+ ret = 0;
+
+fail:
+ qemu_vfree(l2_table);
+ return ret;
+}
+
+/*
* Checks an image for refcount consistency.
*
* Returns 0 if no errors are found, the number of errors in case the image is
@@ -1122,7 +1160,7 @@ int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
/* current L1 table */
ret = check_refcounts_l1(bs, res, refcount_table, nb_clusters,
- s->l1_table_offset, s->l1_size, 1);
+ s->l1_table_offset, s->l1_size);
if (ret < 0) {
goto fail;
}
@@ -1131,7 +1169,7 @@ int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
for(i = 0; i < s->nb_snapshots; i++) {
sn = s->snapshots + i;
ret = check_refcounts_l1(bs, res, refcount_table, nb_clusters,
- sn->l1_table_offset, sn->l1_size, 0);
+ sn->l1_table_offset, sn->l1_size);
if (ret < 0) {
goto fail;
}
@@ -1226,6 +1264,12 @@ int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
}
}
+ /* check OFLAG_COPIED */
+ ret = check_oflag_copied(bs, res);
+ if (ret < 0) {
+ goto fail;
+ }
+
res->image_end_offset = (highest_cluster + 1) * s->cluster_size;
ret = 0;
--
1.7.1