Changed the function names from sect_to_l1_offset(), sect_to_l2_offset() to
get_l1_index(), get_l2_index() as they return index into their respective table.
Signed-off-by: Prasad Joshi <prasadjoshi124@xxxxxxxxx>
---
tools/kvm/qcow.c | 103 ++++++++++++++++++++++++++++++------------------------
1 files changed, 57 insertions(+), 46 deletions(-)
diff --git a/tools/kvm/qcow.c b/tools/kvm/qcow.c
index c4e3e48..3afd3fb 100644
--- a/tools/kvm/qcow.c
+++ b/tools/kvm/qcow.c
@@ -15,14 +15,14 @@
#include <linux/byteorder.h>
#include <linux/types.h>
-static inline uint64_t sect_to_l1_offset(struct qcow *q, uint64_t offset)
+static inline uint64_t get_l1_index(struct qcow *q, uint64_t offset)
{
struct qcow1_header *header = q->header;
return offset >> (header->l2_bits + header->cluster_bits);
}
-static inline uint64_t sect_to_l2_offset(struct qcow *q, uint64_t offset)
+static inline uint64_t get_l2_index(struct qcow *q, uint64_t offset)
{
struct qcow1_header *header = q->header;
@@ -44,54 +44,65 @@ static int qcow1_read_sector(struct disk_image *self, uint64_t sector, void *dst
uint64_t l2_table_size;
uint64_t clust_offset;
uint64_t clust_start;
+ uint64_t clust_size;
uint64_t *l2_table;
uint64_t l1_idx;
uint64_t l2_idx;
uint64_t offset;
-
- offset = sector << SECTOR_SHIFT;
- if (offset >= header->size)
- goto out_error;
-
- l1_idx = sect_to_l1_offset(self->priv, offset);
-
- if (l1_idx >= q->table.table_size)
- goto out_error;
-
- l2_table_offset = be64_to_cpu(q->table.l1_table[l1_idx]);
- if (!l2_table_offset)
- goto zero_sector;
-
- l2_table_size = 1 << header->l2_bits;
-
- l2_table = calloc(l2_table_size, sizeof(uint64_t));
- if (!l2_table)
- goto out_error;
-
- if (pread_in_full(q->fd, l2_table, sizeof(uint64_t) * l2_table_size, l2_table_offset) < 0)
- goto out_error_free_l2;
-
- l2_idx = sect_to_l2_offset(self->priv, offset);
-
- if (l2_idx >= l2_table_size)
- goto out_error_free_l2;
-
- clust_start = be64_to_cpu(l2_table[l2_idx]);
-
- if (!clust_start)
- goto zero_sector;
-
- clust_offset = sect_to_cluster_offset(self->priv, offset);
-
- if (pread_in_full(q->fd, dst, dst_len, clust_start + clust_offset) < 0)
- goto out_error_free_l2;
-
- free(l2_table);
-
- return 0;
-
-zero_sector:
- memset(dst, 0, dst_len);
+ uint32_t length;
+ uint32_t tmp;
+ char *buf = dst;
+
+ clust_size = 1 << header->cluster_bits;
+ length = 0;
+
+ while (length < dst_len) {
+ offset = sector << SECTOR_SHIFT;
+ if (offset >= header->size)
+ goto out_error;
+
+ l1_idx = get_l1_index(self->priv, offset);
+ if (l1_idx >= q->table.table_size)
+ goto out_error;
+
+ l2_table_offset = be64_to_cpu(q->table.l1_table[l1_idx]);
+ if (!l2_table_offset) {
+ tmp = clust_size;
+ memset(buf, 0, tmp);
+ goto next_cluster;
+ }
+
+ l2_table_size = 1 << header->l2_bits;
+
+ l2_table = calloc(l2_table_size, sizeof(uint64_t));
+ if (!l2_table)
+ goto out_error;
+
+ if (pread_in_full(q->fd, l2_table, sizeof(uint64_t) * l2_table_size, l2_table_offset) < 0)
+ goto out_error_free_l2;
+
+ l2_idx = get_l2_index(self->priv, offset);
+ if (l2_idx >= l2_table_size)
+ goto out_error_free_l2;
+
+ clust_start = be64_to_cpu(l2_table[l2_idx]);
+ free(l2_table);
+ if (!clust_start) {
+ tmp = clust_size;
+ memset(buf, 0, tmp);
+ } else {
+ clust_offset = sect_to_cluster_offset(self->priv, offset);
+ tmp = clust_size - clust_offset;
+
+ if (pread_in_full(q->fd, buf, tmp, clust_start + clust_offset) < 0)
+ goto out_error;
+ }
+
+next_cluster:
+ buf += tmp;
+ sector += (tmp >> SECTOR_SHIFT);
+ length += tmp;
+ }
return 0;
--
1.7.1
--
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