When meeting request to write the cluster without copied flag,
allocate a new cluster and write original data with modification
to the new cluster. This also adds support for the writing operation
of the qcow2 compressed image. After testing, image file can pass
through qemu-img check. The performance is needed to be improved.
Signed-off-by: Lan Tianyu tianyu@intel.com
---
tools/kvm/disk/qcow.c| 456 +++---
tools/kvm/include/kvm/qcow.h |2 +
2 files changed, 292 insertions(+), 166 deletions(-)
diff --git a/tools/kvm/disk/qcow.c b/tools/kvm/disk/qcow.c
index 680b37d..400aae8 100644
--- a/tools/kvm/disk/qcow.c
+++ b/tools/kvm/disk/qcow.c
@@ -20,6 +20,16 @@
#include linux/kernel.h
#include linux/types.h
+
+static inline int qcow_pwrite_sync(int fd,
+ void *buf, size_t count, off_t offset)
+{
+ if (pwrite_in_full(fd, buf, count, offset) 0)
+ return -1;
+
+ return fdatasync(fd);
+}
+
static int l2_table_insert(struct rb_root *root, struct qcow_l2_table *new)
{
struct rb_node **link = (root-rb_node), *parent = NULL;
@@ -101,7 +111,8 @@ static int qcow_l2_cache_write(struct qcow *q, struct
qcow_l2_table *c)
size = 1 header-l2_bits;
- if (pwrite_in_full(q-fd, c-table, size * sizeof(u64), c-offset) 0)
+ if (qcow_pwrite_sync(q-fd, c-table,
+ size * sizeof(u64), c-offset) 0)
return -1;
c-dirty = 0;
@@ -122,9 +133,6 @@ static int cache_table(struct qcow *q, struct qcow_l2_table
*c)
*/
lru = list_first_entry(l1t-lru_list, struct qcow_l2_table,
list);
- if (qcow_l2_cache_write(q, lru) 0)
- goto error;
-
/* Remove the node from the cache */
rb_erase(lru-node, r);
list_del_init(lru-list);
@@ -508,47 +516,6 @@ static ssize_t qcow_read_sector(struct disk_image *disk,
u64 sector,
return total;
}
-static inline u64 file_size(int fd)
-{
- struct stat st;
-
- if (fstat(fd, st) 0)
- return 0;
-
- return st.st_size;
-}
-
-static inline int qcow_pwrite_sync(int fd, void *buf, size_t count, off_t
offset)
-{
- if (pwrite_in_full(fd, buf, count, offset) 0)
- return -1;
-
- return fdatasync(fd);
-}
-
-/* Writes a level 2 table at the end of the file. */
-static u64 qcow_write_l2_table(struct qcow *q, u64 *table)
-{
- struct qcow_header *header = q-header;
- u64 clust_sz;
- u64 f_sz;
- u64 off;
- u64 sz;
-
- f_sz= file_size(q-fd);
- if (!f_sz)
- return 0;
-
- sz = 1 header-l2_bits;
- clust_sz= 1 header-cluster_bits;
- off = ALIGN(f_sz, clust_sz);
-
- if (pwrite_in_full(q-fd, table, sz * sizeof(u64), off) 0)
- return 0;
-
- return off;
-}
-
static void refcount_table_free_cache(struct qcow_refcount_table *rft)
{
struct rb_root *r = rft-root;
@@ -601,7 +568,8 @@ static int write_refcount_block(struct qcow *q, struct
qcow_refcount_block *rfb)
if (!rfb-dirty)
return 0;
- if (pwrite_in_full(q-fd, rfb-entries, rfb-size * sizeof(u16),
rfb-offset) 0)
+ if (qcow_pwrite_sync(q-fd, rfb-entries,
+ rfb-size * sizeof(u16), rfb-offset) 0)
return -1;
rfb-dirty = 0;
@@ -618,9 +586,6 @@ static int cache_refcount_block(struct qcow *q, struct
qcow_refcount_block *c)
if (rft-nr_cached == MAX_CACHE_NODES) {
lru = list_first_entry(rft-lru_list, struct
qcow_refcount_block, list);
- if (write_refcount_block(q, lru) 0)
- goto error;
-
rb_erase(lru-node, r);
list_del_init(lru-list);
rft-nr_cached--;
@@ -706,6 +671,11 @@ static struct qcow_refcount_block
*qcow_read_refcount_block(struct qcow *q, u64
rfb_offset = be64_to_cpu(rft-rf_table[rft_idx]);
+ if (!rfb_offset) {
+ pr_warning(Don't support to grow refcount table);
+ return NULL;
+ }
+
rfb = refcount_block_search(q, rfb_offset);
if (rfb)
return rfb;
@@ -728,35 +698,140 @@ error_free_rfb:
return NULL;
}
+static u16 qcow_get_refcount(struct qcow *q, u64 clust_idx)
+{
+ struct qcow_refcount_block *rfb = NULL;
+ struct qcow_header *header = q-header;
+ u64 rfb_idx;
+
+ rfb = qcow_read_refcount_block(q, clust_idx);
+ if (!rfb) {
+ pr_warning(Error while reading refcount table);
+ return -1;
+ }
+
+ rfb_idx = clust_idx (((1ULL
+ (header-cluster_bits - QCOW_REFCOUNT_BLOCK_SHIFT)) - 1));
+
+ if (rfb_idx = rfb-size) {
+ pr_warning(L1: refcount block index out of bounds);
+ return -1;
+ }
+
+
