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-rw-r--r--block/qcow2-cluster.c94
-rw-r--r--block/qcow2-refcount.c42
-rw-r--r--block/qcow2.c16
-rw-r--r--block/qcow2.h4
4 files changed, 99 insertions, 57 deletions
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index c11680d12a..03a9f25799 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -157,31 +157,36 @@ static uint64_t *seek_l2_table(BDRVQcowState *s, uint64_t l2_offset)
* the image file failed.
*/
-static uint64_t *l2_load(BlockDriverState *bs, uint64_t l2_offset)
+static int l2_load(BlockDriverState *bs, uint64_t l2_offset,
+ uint64_t **l2_table)
{
BDRVQcowState *s = bs->opaque;
int min_index;
- uint64_t *l2_table;
+ int ret;
/* seek if the table for the given offset is in the cache */
- l2_table = seek_l2_table(s, l2_offset);
- if (l2_table != NULL)
- return l2_table;
+ *l2_table = seek_l2_table(s, l2_offset);
+ if (*l2_table != NULL) {
+ return 0;
+ }
/* not found: load a new entry in the least used one */
min_index = l2_cache_new_entry(bs);
- l2_table = s->l2_cache + (min_index << s->l2_bits);
+ *l2_table = s->l2_cache + (min_index << s->l2_bits);
BLKDBG_EVENT(bs->file, BLKDBG_L2_LOAD);
- if (bdrv_pread(bs->file, l2_offset, l2_table, s->l2_size * sizeof(uint64_t)) !=
- s->l2_size * sizeof(uint64_t))
- return NULL;
+ ret = bdrv_pread(bs->file, l2_offset, *l2_table,
+ s->l2_size * sizeof(uint64_t));
+ if (ret < 0) {
+ return ret;
+ }
+
s->l2_cache_offsets[min_index] = l2_offset;
s->l2_cache_counts[min_index] = 1;
- return l2_table;
+ return 0;
}
/*
@@ -239,14 +244,6 @@ static int l2_allocate(BlockDriverState *bs, int l1_index, uint64_t **table)
return l2_offset;
}
- /* update the L1 entry */
-
- s->l1_table[l1_index] = l2_offset | QCOW_OFLAG_COPIED;
- ret = write_l1_entry(bs, l1_index);
- if (ret < 0) {
- return ret;
- }
-
/* allocate a new entry in the l2 cache */
min_index = l2_cache_new_entry(bs);
@@ -261,7 +258,7 @@ static int l2_allocate(BlockDriverState *bs, int l1_index, uint64_t **table)
ret = bdrv_pread(bs->file, old_l2_offset, l2_table,
s->l2_size * sizeof(uint64_t));
if (ret < 0) {
- return ret;
+ goto fail;
}
}
/* write the l2 table to the file */
@@ -269,7 +266,14 @@ static int l2_allocate(BlockDriverState *bs, int l1_index, uint64_t **table)
ret = bdrv_pwrite(bs->file, l2_offset, l2_table,
s->l2_size * sizeof(uint64_t));
if (ret < 0) {
- return ret;
+ goto fail;
+ }
+
+ /* update the L1 entry */
+ s->l1_table[l1_index] = l2_offset | QCOW_OFLAG_COPIED;
+ ret = write_l1_entry(bs, l1_index);
+ if (ret < 0) {
+ goto fail;
}
/* update the l2 cache entry */
@@ -279,6 +283,10 @@ static int l2_allocate(BlockDriverState *bs, int l1_index, uint64_t **table)
*table = l2_table;
return 0;
+
+fail:
+ qcow2_l2_cache_reset(bs);
+ return ret;
}
static int count_contiguous_clusters(uint64_t nb_clusters, int cluster_size,
@@ -342,7 +350,13 @@ static int qcow_read(BlockDriverState *bs, int64_t sector_num,
while (nb_sectors > 0) {
n = nb_sectors;
- cluster_offset = qcow2_get_cluster_offset(bs, sector_num << 9, &n);
+
+ ret = qcow2_get_cluster_offset(bs, sector_num << 9, &n,
+ &cluster_offset);
+ if (ret < 0) {
+ return ret;
+ }
+
index_in_cluster = sector_num & (s->cluster_sectors - 1);
if (!cluster_offset) {
if (bs->backing_hd) {
@@ -409,28 +423,29 @@ static int copy_sectors(BlockDriverState *bs, uint64_t start_sect,
/*
* get_cluster_offset
*
- * For a given offset of the disk image, return cluster offset in
- * qcow2 file.
+ * For a given offset of the disk image, find the cluster offset in
+ * qcow2 file. The offset is stored in *cluster_offset.
*
* on entry, *num is the number of contiguous clusters we'd like to
* access following offset.
*
* on exit, *num is the number of contiguous clusters we can read.
*
- * Return 1, if the offset is found
- * Return 0, otherwise.
+ * Return 0, if the offset is found
+ * Return -errno, otherwise.
*
*/
-uint64_t qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
- int *num)
+int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
+ int *num, uint64_t *cluster_offset)
{
BDRVQcowState *s = bs->opaque;
unsigned int l1_index, l2_index;
- uint64_t l2_offset, *l2_table, cluster_offset;
+ uint64_t l2_offset, *l2_table;
int l1_bits, c;
unsigned int index_in_cluster, nb_clusters;
uint64_t nb_available, nb_needed;
+ int ret;
index_in_cluster = (offset >> 9) & (s->cluster_sectors - 1);
nb_needed = *num + index_in_cluster;
@@ -451,7 +466,7 @@ uint64_t qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
nb_needed = nb_available;
}
- cluster_offset = 0;
+ *cluster_offset = 0;
/* seek the the l2 offset in the l1 table */
@@ -469,17 +484,18 @@ uint64_t qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
/* load the l2 table in memory */
l2_offset &= ~QCOW_OFLAG_COPIED;
- l2_table = l2_load(bs, l2_offset);
- if (l2_table == NULL)
- return 0;
+ ret = l2_load(bs, l2_offset, &l2_table);
+ if (ret < 0) {
+ return ret;
+ }
/* find the cluster offset for the given disk offset */
l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1);
- cluster_offset = be64_to_cpu(l2_table[l2_index]);
+ *cluster_offset = be64_to_cpu(l2_table[l2_index]);
nb_clusters = size_to_clusters(s, nb_needed << 9);
- if (!cluster_offset) {
+ if (!*cluster_offset) {
/* how many empty clusters ? */
c = count_contiguous_free_clusters(nb_clusters, &l2_table[l2_index]);
} else {
@@ -495,7 +511,8 @@ out:
*num = nb_available - index_in_cluster;
- return cluster_offset & ~QCOW_OFLAG_COPIED;
+ *cluster_offset &=~QCOW_OFLAG_COPIED;
+ return 0;
}
/*
@@ -536,9 +553,9 @@ static int get_cluster_table(BlockDriverState *bs, uint64_t offset,
if (l2_offset & QCOW_OFLAG_COPIED) {
/* load the l2 table in memory */
l2_offset &= ~QCOW_OFLAG_COPIED;
- l2_table = l2_load(bs, l2_offset);
- if (l2_table == NULL) {
- return -EIO;
+ ret = l2_load(bs, l2_offset, &l2_table);
+ if (ret < 0) {
+ return ret;
}
} else {
if (l2_offset)
@@ -696,6 +713,7 @@ int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m)
ret = write_l2_entries(bs, l2_table, l2_offset, l2_index, m->nb_clusters);
if (ret < 0) {
+ qcow2_l2_cache_reset(bs);
goto err;
}
diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c
index 744107cd1d..22b0b45ff7 100644
--- a/block/qcow2-refcount.c
+++ b/block/qcow2-refcount.c
@@ -221,8 +221,6 @@ static int64_t alloc_refcount_block(BlockDriverState *bs, int64_t cluster_index)
/* Allocate the refcount block itself and mark it as used */
uint64_t new_block = alloc_clusters_noref(bs, s->cluster_size);
- memset(s->refcount_block_cache, 0, s->cluster_size);
- s->refcount_block_cache_offset = new_block;
#ifdef DEBUG_ALLOC2
fprintf(stderr, "qcow2: Allocate refcount block %d for %" PRIx64
@@ -231,6 +229,10 @@ static int64_t alloc_refcount_block(BlockDriverState *bs, int64_t cluster_index)
#endif
if (in_same_refcount_block(s, new_block, cluster_index << s->cluster_bits)) {
+ /* Zero the new refcount block before updating it */
+ memset(s->refcount_block_cache, 0, s->cluster_size);
+ s->refcount_block_cache_offset = new_block;
+
/* The block describes itself, need to update the cache */
int block_index = (new_block >> s->cluster_bits) &
((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1);
@@ -242,6 +244,11 @@ static int64_t alloc_refcount_block(BlockDriverState *bs, int64_t cluster_index)
if (ret < 0) {
goto fail_block;
}
+
+ /* Initialize the new refcount block only after updating its refcount,
+ * update_refcount uses the refcount cache itself */
+ memset(s->refcount_block_cache, 0, s->cluster_size);
+ s->refcount_block_cache_offset = new_block;
}
/* Now the new refcount block needs to be written to disk */
@@ -404,22 +411,28 @@ static int write_refcount_block_entries(BlockDriverState *bs,
{
BDRVQcowState *s = bs->opaque;
size_t size;
+ int ret;
if (cache_refcount_updates) {
return 0;
}
+ if (first_index < 0) {
+ return 0;
+ }
+
first_index &= ~(REFCOUNTS_PER_SECTOR - 1);
last_index = (last_index + REFCOUNTS_PER_SECTOR)
& ~(REFCOUNTS_PER_SECTOR - 1);
size = (last_index - first_index) << REFCOUNT_SHIFT;
+
BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_UPDATE_PART);
- if (bdrv_pwrite(bs->file,
+ ret = bdrv_pwrite(bs->file,
refcount_block_offset + (first_index << REFCOUNT_SHIFT),
- &s->refcount_block_cache[first_index], size) != size)
- {
- return -EIO;
+ &s->refcount_block_cache[first_index], size);
+ if (ret < 0) {
+ return ret;
}
return 0;
@@ -460,10 +473,10 @@ static int QEMU_WARN_UNUSED_RESULT update_refcount(BlockDriverState *bs,
table_index = cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT);
if ((old_table_index >= 0) && (table_index != old_table_index)) {
- if (write_refcount_block_entries(bs, refcount_block_offset,
- first_index, last_index) < 0)
- {
- return -EIO;
+ ret = write_refcount_block_entries(bs, refcount_block_offset,
+ first_index, last_index);
+ if (ret < 0) {
+ return ret;
}
first_index = -1;
@@ -505,10 +518,11 @@ fail:
/* Write last changed block to disk */
if (refcount_block_offset != 0) {
- if (write_refcount_block_entries(bs, refcount_block_offset,
- first_index, last_index) < 0)
- {
- return ret < 0 ? ret : -EIO;
+ int wret;
+ wret = write_refcount_block_entries(bs, refcount_block_offset,
+ first_index, last_index);
+ if (wret < 0) {
+ return ret < 0 ? ret : wret;
}
}
diff --git a/block/qcow2.c b/block/qcow2.c
index 5b72758915..33fa9a9012 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -297,9 +297,15 @@ static int qcow_is_allocated(BlockDriverState *bs, int64_t sector_num,
int nb_sectors, int *pnum)
{
uint64_t cluster_offset;
+ int ret;
*pnum = nb_sectors;
- cluster_offset = qcow2_get_cluster_offset(bs, sector_num << 9, pnum);
+ /* FIXME We can get errors here, but the bdrv_is_allocated interface can't
+ * pass them on today */
+ ret = qcow2_get_cluster_offset(bs, sector_num << 9, pnum, &cluster_offset);
+ if (ret < 0) {
+ *pnum = 0;
+ }
return (cluster_offset != 0);
}
@@ -409,8 +415,12 @@ static void qcow_aio_read_cb(void *opaque, int ret)
/* prepare next AIO request */
acb->cur_nr_sectors = acb->remaining_sectors;
- acb->cluster_offset = qcow2_get_cluster_offset(bs, acb->sector_num << 9,
- &acb->cur_nr_sectors);
+ ret = qcow2_get_cluster_offset(bs, acb->sector_num << 9,
+ &acb->cur_nr_sectors, &acb->cluster_offset);
+ if (ret < 0) {
+ goto done;
+ }
+
index_in_cluster = acb->sector_num & (s->cluster_sectors - 1);
if (!acb->cluster_offset) {
diff --git a/block/qcow2.h b/block/qcow2.h
index 01053b79d9..c59b827da8 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -196,8 +196,8 @@ void qcow2_encrypt_sectors(BDRVQcowState *s, int64_t sector_num,
int nb_sectors, int enc,
const AES_KEY *key);
-uint64_t qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
- int *num);
+int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
+ int *num, uint64_t *cluster_offset);
int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset,
int n_start, int n_end, int *num, QCowL2Meta *m);
uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
generated by cgit v1.2.3 (git 2.26.2) at 2025-01-10 02:49:36 +0000