This patch adds the decompression operation when confirming the qcow or
qcow2 image is compressed. This patch also divides the read cluster
fucntion into two which are respective for qcow and qcow2 in order to be
convenient to support these two kind images. Add some macros for qcow.
Signed-off-by: Lan Tianyu <tianyu.lan@xxxxxxxxx>
---
tools/kvm/Makefile | 1 +
tools/kvm/disk/qcow.c | 315 ++++++++++++++++++++++++++++++++++--------
tools/kvm/include/kvm/qcow.h | 33 +++--
3 files changed, 276 insertions(+), 73 deletions(-)
diff --git a/tools/kvm/Makefile b/tools/kvm/Makefile
index fef624d..0d0da4b 100644
--- a/tools/kvm/Makefile
+++ b/tools/kvm/Makefile
@@ -116,6 +116,7 @@ OBJS += bios/bios-rom.o
LIBS += -lrt
LIBS += -lpthread
LIBS += -lutil
+LIBS += -lz
# Additional ARCH settings for x86
ARCH ?= $(shell echo $(uname_M) | sed -e s/i.86/i386/ -e s/sun4u/sparc64/ \
diff --git a/tools/kvm/disk/qcow.c b/tools/kvm/disk/qcow.c
index 2471aeb..2f5c16a 100644
--- a/tools/kvm/disk/qcow.c
+++ b/tools/kvm/disk/qcow.c
@@ -12,6 +12,7 @@
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
+#include <zlib.h>
#include <linux/byteorder.h>
#include <linux/kernel.h>
@@ -233,12 +234,41 @@ error:
return NULL;
}
-static ssize_t qcow_read_cluster(struct qcow *q, u64 offset, void *dst, u32 dst_len)
+static int qcow_decompress_buffer(u8 *out_buf, int out_buf_size,
+ const u8 *buf, int buf_size)
+{
+ z_stream strm1, *strm = &strm1;
+ int ret, out_len;
+
+ memset(strm, 0, sizeof(*strm));
+
+ strm->next_in = (u8 *)buf;
+ strm->avail_in = buf_size;
+ strm->next_out = out_buf;
+ strm->avail_out = out_buf_size;
+
+ ret = inflateInit2(strm, -12);
+ if (ret != Z_OK)
+ return -1;
+
+ ret = inflate(strm, Z_FINISH);
+ out_len = strm->next_out - out_buf;
+ if ((ret != Z_STREAM_END && ret != Z_BUF_ERROR) ||
+ out_len != out_buf_size) {
+ inflateEnd(strm);
+ return -1;
+ }
+
+ inflateEnd(strm);
+ return 0;
+}
+
+static ssize_t qcow1_read_cluster(struct qcow *q, u64 offset,
+ void *dst, u32 dst_len)
{
struct qcow_header *header = q->header;
struct qcow_l1_table *l1t = &q->table;
struct qcow_l2_table *l2t;
- u64 cluster_size;
u64 clust_offset;
u64 clust_start;
u64 l2t_offset;
@@ -246,30 +276,24 @@ static ssize_t qcow_read_cluster(struct qcow *q, u64 offset, void *dst, u32 dst_
u64 l2t_size;
u64 l1_idx;
u64 l2_idx;
-
- cluster_size = 1 << header->cluster_bits;
+ int coffset;
+ int csize;
l1_idx = get_l1_index(q, offset);
if (l1_idx >= l1t->table_size)
return -1;
clust_offset = get_cluster_offset(q, offset);
- if (clust_offset >= cluster_size)
+ if (clust_offset >= q->cluster_size)
return -1;
- length = cluster_size - clust_offset;
+ length = q->cluster_size - clust_offset;
if (length > dst_len)
length = dst_len;
mutex_lock(&q->mutex);
l2t_offset = be64_to_cpu(l1t->l1_table[l1_idx]);
- if (l2t_offset & QCOW_OFLAG_COMPRESSED) {
- pr_warning("compressed sectors are not supported");
- goto out_error;
- }
-
- l2t_offset &= QCOW_OFFSET_MASK;
if (!l2t_offset)
goto zero_cluster;
@@ -285,20 +309,130 @@ static ssize_t qcow_read_cluster(struct qcow *q, u64 offset, void *dst, u32 dst_
goto out_error;
clust_start = be64_to_cpu(l2t->table[l2_idx]);
- if (clust_start & QCOW_OFLAG_COMPRESSED) {
- pr_warning("compressed sectors are not supported");
- goto out_error;
+ if (clust_start & QCOW1_OFLAG_COMPRESSED) {
+ coffset = clust_start & q->cluster_offset_mask;
+ csize = clust_start >> (63 - q->header->cluster_bits);
+ csize &= (q->cluster_size - 1);
+
+ if (pread_in_full(q->fd, q->cluster_data, csize,
+ coffset) < 0) {
+ goto out_error;
+ }
+
+ if (qcow_decompress_buffer(q->cluster_cache, q->cluster_size,
+ q->cluster_data, csize) < 0) {
+ goto out_error;
+ }
+
+ memcpy(dst, q->cluster_cache + clust_offset, length);
+ mutex_unlock(&q->mutex);
+ } else{
+ if (!clust_start)
+ goto zero_cluster;
+
+ mutex_unlock(&q->mutex);
+
+ if (pread_in_full(q->fd, dst, length,
+ clust_start + clust_offset) < 0)
+ return -1;
}
- clust_start &= QCOW_OFFSET_MASK;
- if (!clust_start)
- goto zero_cluster;
+ return length;
+
+zero_cluster:
+ mutex_unlock(&q->mutex);
+ memset(dst, 0, length);
+ return length;
+out_error:
mutex_unlock(&q->mutex);
+ length = -1;
+ return -1;
+}
+
+static ssize_t qcow2_read_cluster(struct qcow *q, u64 offset,
+ void *dst, u32 dst_len)
+{
+ struct qcow_header *header = q->header;
+ struct qcow_l1_table *l1t = &q->table;
+ struct qcow_l2_table *l2t;
+ u64 clust_offset;
+ u64 clust_start;
+ u64 l2t_offset;
+ size_t length;
+ u64 l2t_size;
+ u64 l1_idx;
+ u64 l2_idx;
+ int coffset;
+ int sector_offset;
+ int nb_csectors;
+ int csize;
+
+ l1_idx = get_l1_index(q, offset);
+ if (l1_idx >= l1t->table_size)
+ return -1;
- if (pread_in_full(q->fd, dst, length, clust_start + clust_offset) < 0)
+ clust_offset = get_cluster_offset(q, offset);
+ if (clust_offset >= q->cluster_size)
return -1;
+ length = q->cluster_size - clust_offset;
+ if (length > dst_len)
+ length = dst_len;
+
+ mutex_lock(&q->mutex);
+
+ l2t_offset = be64_to_cpu(l1t->l1_table[l1_idx]);
+
+ l2t_offset &= ~QCOW2_OFLAG_COPIED;
+ if (!l2t_offset)
+ goto zero_cluster;
+
+ l2t_size = 1 << header->l2_bits;
+
+ /* read and cache level 2 table */
+ l2t = qcow_read_l2_table(q, l2t_offset);
+ if (!l2t)
+ goto out_error;
+
+ l2_idx = get_l2_index(q, offset);
+ if (l2_idx >= l2t_size)
+ goto out_error;
+
+ clust_start = be64_to_cpu(l2t->table[l2_idx]);
+ if (clust_start & QCOW2_OFLAG_COMPRESSED) {
+ coffset = clust_start & q->cluster_offset_mask;
+ nb_csectors = ((clust_start >> q->csize_shift)
+ & q->csize_mask) + 1;
+ sector_offset = coffset & (SECTOR_SIZE - 1);
+ csize = nb_csectors * SECTOR_SIZE - sector_offset;
+
+ if (pread_in_full(q->fd, q->cluster_data,
+ nb_csectors * SECTOR_SIZE,
+ coffset & ~(SECTOR_SIZE - 1)) < 0) {
+ goto out_error;
+ }
+
+ if (qcow_decompress_buffer(q->cluster_cache, q->cluster_size,
+ q->cluster_data + sector_offset,
+ csize) < 0) {
+ goto out_error;
+ }
+
+ memcpy(dst, q->cluster_cache + clust_offset, length);
+ mutex_unlock(&q->mutex);
+ } else{
+ clust_start &= QCOW2_OFFSET_MASK;
+ if (!clust_start)
+ goto zero_cluster;
+
+ mutex_unlock(&q->mutex);
+
+ if (pread_in_full(q->fd, dst, length,
+ clust_start + clust_offset) < 0)
+ return -1;
+ }
+
return length;
zero_cluster:
@@ -312,7 +446,8 @@ out_error:
return -1;
}
-static ssize_t qcow_read_sector(struct disk_image *disk, u64 sector, void *dst, u32 dst_len)
+static ssize_t qcow_read_sector(struct disk_image *disk, u64 sector,
+ void *dst, u32 dst_len)
{
struct qcow *q = disk->priv;
struct qcow_header *header = q->header;
@@ -329,7 +464,13 @@ static ssize_t qcow_read_sector(struct disk_image *disk, u64 sector, void *dst,
if (offset >= header->size)
return -1;
- nr = qcow_read_cluster(q, offset, buf, dst_len - nr_read);
+ if (q->version == QCOW1_VERSION)
+ nr = qcow1_read_cluster(q, offset, buf,
+ dst_len - nr_read);
+ else
+ nr = qcow2_read_cluster(q, offset, buf,
+ dst_len - nr_read);
+
if (nr <= 0)
return -1;
@@ -474,18 +615,14 @@ error:
static struct qcow_refcount_block *new_refcount_block(struct qcow *q, u64 rfb_offset)
{
- struct qcow_header *header = q->header;
struct qcow_refcount_block *rfb;
- u64 cluster_size;
-
- cluster_size = 1 << header->cluster_bits;
- rfb = malloc(sizeof *rfb + cluster_size);
+ rfb = malloc(sizeof *rfb + q->cluster_size);
if (!rfb)
return NULL;
rfb->offset = rfb_offset;
- rfb->size = cluster_size / sizeof(u16);
+ rfb->size = q->cluster_size / sizeof(u16);
RB_CLEAR_NODE(&rfb->node);
INIT_LIST_HEAD(&rfb->list);
@@ -614,16 +751,16 @@ static ssize_t qcow_write_cluster(struct qcow *q, u64 offset, void *buf, u32 src
mutex_lock(&q->mutex);
l2t_offset = be64_to_cpu(l1t->l1_table[l1t_idx]);
- if (l2t_offset & QCOW_OFLAG_COMPRESSED) {
+ if (l2t_offset & QCOW2_OFLAG_COMPRESSED) {
pr_warning("compressed clusters are not supported");
goto error;
}
- if (!(l2t_offset & QCOW_OFLAG_COPIED)) {
+ if (!(l2t_offset & QCOW2_OFLAG_COPIED)) {
pr_warning("L2 copy-on-write clusters are not supported");
goto error;
}
- l2t_offset &= QCOW_OFFSET_MASK;
+ l2t_offset &= QCOW2_OFFSET_MASK;
if (l2t_offset) {
/* read and cache l2 table */
l2t = qcow_read_l2_table(q, l2t_offset);
@@ -662,26 +799,27 @@ static ssize_t qcow_write_cluster(struct qcow *q, u64 offset, void *buf, u32 src
clust_start = be64_to_cpu(l2t->table[l2t_idx]);
- clust_flags = clust_start & QCOW_OFLAGS_MASK;
- if (clust_flags & QCOW_OFLAG_COMPRESSED) {
+ clust_flags = clust_start & QCOW2_OFLAGS_MASK;
+ if (clust_flags & QCOW2_OFLAG_COMPRESSED) {
pr_warning("compressed clusters are not supported");
goto error;
}
- clust_start &= QCOW_OFFSET_MASK;
+ clust_start &= QCOW2_OFFSET_MASK;
if (!clust_start) {
clust_start = ALIGN(f_sz, clust_sz);
- l2t->table[l2t_idx] = cpu_to_be64(clust_start | QCOW_OFLAG_COPIED);
+ l2t->table[l2t_idx] = cpu_to_be64(clust_start | QCOW2_OFLAG_COPIED);
l2t->dirty = 1;
}
- if (!(clust_flags & QCOW_OFLAG_COPIED)) {
+ if (!(clust_flags & QCOW2_OFLAG_COPIED)) {
struct qcow_refcount_block *rfb = NULL;
u16 clust_refcount;
u64 clust_idx;
u64 rfb_idx;
- clust_idx = (clust_start & QCOW_OFFSET_MASK) >> (header->cluster_bits);
+ clust_idx = (clust_start & QCOW2_OFFSET_MASK)
+ >> (header->cluster_bits);
rfb = qcow_read_refcount_block(q, clust_idx);
if (!rfb) {
@@ -816,6 +954,8 @@ static int qcow_disk_close(struct disk_image *disk)
refcount_table_free_cache(&q->refcount_table);
l1_table_free_cache(&q->table);
+ free(q->cluster_data);
+ free(q->cluster_cache);
free(q->refcount_table.rf_table);
free(q->table.l1_table);
free(q->header);
@@ -841,11 +981,9 @@ static int qcow_read_refcount_table(struct qcow *q)
{
struct qcow_header *header = q->header;
struct qcow_refcount_table *rft = &q->refcount_table;
- u64 cluster_size;
- cluster_size = 1 << header->cluster_bits;
-
- rft->rf_size = (header->refcount_table_size * cluster_size) / sizeof(u64);
+ rft->rf_size = (header->refcount_table_size * q->cluster_size)
+ / sizeof(u64);
rft->rf_table = calloc(rft->rf_size, sizeof(u64));
if (!rft->rf_table)
@@ -921,7 +1059,7 @@ static struct disk_image *qcow2_probe(int fd, bool readonly)
q = calloc(1, sizeof(struct qcow));
if (!q)
- goto error;
+ return NULL;
mutex_init(&q->mutex);
q->fd = fd;
@@ -933,13 +1071,31 @@ static struct disk_image *qcow2_probe(int fd, bool readonly)
h = q->header = qcow2_read_header(fd);
if (!h)
- goto error;
+ goto free_qcow;
+
+ q->version = QCOW2_VERSION;
+ q->csize_shift = (62 - (q->header->cluster_bits - 8));
+ q->csize_mask = (1 << (q->header->cluster_bits - 8)) - 1;
+ q->cluster_offset_mask = (1LL << q->csize_shift) - 1;
+ q->cluster_size = 1 << q->header->cluster_bits;
+
+ q->cluster_data = malloc(q->cluster_size);
+ if (!q->cluster_data) {
+ pr_warning("cluster data malloc error!");
+ goto free_header;
+ }
+
+ q->cluster_cache = malloc(q->cluster_size);
+ if (!q->cluster_cache) {
+ pr_warning("cluster cache malloc error!");
+ goto free_cluster_data;
+ }
if (qcow_read_l1_table(q) < 0)
- goto error;
+ goto free_cluster_cache;
if (qcow_read_refcount_table(q) < 0)
- goto error;
+ goto free_l1_table;
/*
* Do not use mmap use read/write instead
@@ -950,17 +1106,29 @@ static struct disk_image *qcow2_probe(int fd, bool readonly)
disk_image = disk_image__new(fd, h->size, &qcow_disk_ops, DISK_IMAGE_NOMMAP);
if (!disk_image)
- goto error;
+ goto free_refcount_table;
disk_image->priv = q;
return disk_image;
-error:
- if (!q)
- return NULL;
- free(q->table.l1_table);
- free(q->header);
- free(q);
+free_refcount_table:
+ if (q->refcount_table.rf_table)
+ free(q->refcount_table.rf_table);
+free_l1_table:
+ if (q->table.l1_table)
+ free(q->table.l1_table);
+free_cluster_cache:
+ if (q->cluster_cache)
+ free(q->cluster_cache);
+free_cluster_data:
+ if (q->cluster_data)
+ free(q->cluster_data);
+free_header:
+ if (q->header)
+ free(q->header);
+free_qcow:
+ if (q)
+ free(q);
return NULL;
}
@@ -1027,7 +1195,7 @@ static struct disk_image *qcow1_probe(int fd, bool readonly)
q = calloc(1, sizeof(struct qcow));
if (!q)
- goto error;
+ return NULL;
mutex_init(&q->mutex);
q->fd = fd;
@@ -1039,10 +1207,26 @@ static struct disk_image *qcow1_probe(int fd, bool readonly)
h = q->header = qcow1_read_header(fd);
if (!h)
- goto error;
+ goto free_qcow;
+
+ q->version = QCOW1_VERSION;
+ q->cluster_size = 1 << q->header->cluster_bits;
+ q->cluster_offset_mask = (1LL << (63 - q->header->cluster_bits)) - 1;
+
+ q->cluster_data = malloc(q->cluster_size);
+ if (!q->cluster_data) {
+ pr_warning("cluster data malloc error!");
+ goto free_header;
+ }
+
+ q->cluster_cache = malloc(q->cluster_size);
+ if (!q->cluster_cache) {
+ pr_warning("cluster cache malloc error!");
+ goto free_cluster_data;
+ }
if (qcow_read_l1_table(q) < 0)
- goto error;
+ goto free_cluster_cache;
/*
* Do not use mmap use read/write instead
@@ -1053,17 +1237,26 @@ static struct disk_image *qcow1_probe(int fd, bool readonly)
disk_image = disk_image__new(fd, h->size, &qcow_disk_ops, DISK_IMAGE_NOMMAP);
if (!disk_image)
- goto error;
+ goto free_l1_table;
disk_image->priv = q;
return disk_image;
-error:
- if (!q)
- return NULL;
- free(q->table.l1_table);
- free(q->header);
- free(q);
+free_l1_table:
+ if (q->table.l1_table)
+ free(q->table.l1_table);
+free_cluster_cache:
+ if (q->cluster_cache)
+ free(q->cluster_cache);
+free_cluster_data:
+ if (q->cluster_data)
+ free(q->cluster_data);
+free_header:
+ if (q->header)
+ free(q->header);
+free_qcow:
+ if (q)
+ free(q);
return NULL;
}
diff --git a/tools/kvm/include/kvm/qcow.h b/tools/kvm/include/kvm/qcow.h
index 46db702..bbf7913 100644
--- a/tools/kvm/include/kvm/qcow.h
+++ b/tools/kvm/include/kvm/qcow.h
@@ -13,12 +13,14 @@
#define QCOW1_VERSION 1
#define QCOW2_VERSION 2
-#define QCOW_OFLAG_COPIED (1ULL << 63)
-#define QCOW_OFLAG_COMPRESSED (1ULL << 62)
+#define QCOW1_OFLAG_COMPRESSED (1ULL << 63)
-#define QCOW_OFLAGS_MASK (QCOW_OFLAG_COPIED|QCOW_OFLAG_COMPRESSED)
+#define QCOW2_OFLAG_COPIED (1ULL << 63)
+#define QCOW2_OFLAG_COMPRESSED (1ULL << 62)
-#define QCOW_OFFSET_MASK (~QCOW_OFLAGS_MASK)
+#define QCOW2_OFLAGS_MASK (QCOW2_OFLAG_COPIED|QCOW2_OFLAG_COMPRESSED)
+
+#define QCOW2_OFFSET_MASK (~QCOW2_OFLAGS_MASK)
#define MAX_CACHE_NODES 32
@@ -61,14 +63,6 @@ struct qcow_refcount_table {
int nr_cached;
};
-struct qcow {
- pthread_mutex_t mutex;
- void *header;
- struct qcow_l1_table table;
- struct qcow_refcount_table refcount_table;
- int fd;
-};
-
struct qcow_header {
u64 size; /* in bytes */
u64 l1_table_offset;
@@ -79,6 +73,21 @@ struct qcow_header {
u32 refcount_table_size;
};
+struct qcow {
+ pthread_mutex_t mutex;
+ struct qcow_header *header;
+ struct qcow_l1_table table;
+ struct qcow_refcount_table refcount_table;
+ int fd;
+ int csize_shift;
+ int csize_mask;
+ u32 version;
+ u64 cluster_size;
+ u64 cluster_offset_mask;
+ void *cluster_cache;
+ void *cluster_data;
+};
+
struct qcow1_header_disk {
u32 magic;
u32 version;
--
1.7.6.rc2.8.g28eb
--
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