diff mbox series

[v5,2/3] qcow2: rework the cluster compression routine

Message ID 20190904152915.30755-3-dplotnikov@virtuozzo.com (mailing list archive)
State New, archived
Headers show
Series qcow2: add zstd cluster compression | expand

Commit Message

Denis Plotnikov Sept. 4, 2019, 3:29 p.m. UTC 
The patch allow to process image compression type defined
in the image header and choose an appropriate method for
image clusters (de)compression.

Signed-off-by: Denis Plotnikov <dplotnikov@virtuozzo.com>
---
 block/qcow2-threads.c | 77 +++++++++++++++++++++++++++++++++++--------
 1 file changed, 63 insertions(+), 14 deletions(-)

Comments

Eric Blake Sept. 4, 2019, 3:46 p.m. UTC | #1 
On 9/4/19 10:29 AM, Denis Plotnikov wrote:
> The patch allow to process image compression type defined
> in the image header and choose an appropriate method for
> image clusters (de)compression.
> 
> Signed-off-by: Denis Plotnikov <dplotnikov@virtuozzo.com>
> ---
>  block/qcow2-threads.c | 77 +++++++++++++++++++++++++++++++++++--------
>  1 file changed, 63 insertions(+), 14 deletions(-)
> 
Reviewed-by: Eric Blake <eblake@redhat.com>
Eric Blake Sept. 4, 2019, 3:46 p.m. UTC | #2 
On 9/4/19 10:29 AM, Denis Plotnikov wrote:
> The patch allow to process image compression type defined

s/allow to process/allows processing the/

> in the image header and choose an appropriate method for

s/choose/chooses/

> image clusters (de)compression.
> 
> Signed-off-by: Denis Plotnikov <dplotnikov@virtuozzo.com>
> ---
>  block/qcow2-threads.c | 77 +++++++++++++++++++++++++++++++++++--------
>  1 file changed, 63 insertions(+), 14 deletions(-)
>
diff mbox series

Patch

diff --git a/block/qcow2-threads.c b/block/qcow2-threads.c
index 3b1e63fe41..ebeef9e568 100644
--- a/block/qcow2-threads.c
+++ b/block/qcow2-threads.c
@@ -74,7 +74,9 @@  typedef struct Qcow2CompressData {
 } Qcow2CompressData;
 
 /*
- * qcow2_compress()
+ * qcow2_zlib_compress()
+ *
+ * Compress @src_size bytes of data using zlib compression method
  *
  * @dest - destination buffer, @dest_size bytes
  * @src - source buffer, @src_size bytes
@@ -83,8 +85,8 @@  typedef struct Qcow2CompressData {
  *          -ENOMEM destination buffer is not enough to store compressed data
  *          -EIO    on any other error
  */
-static ssize_t qcow2_compress(void *dest, size_t dest_size,
-                              const void *src, size_t src_size)
+static ssize_t qcow2_zlib_compress(void *dest, size_t dest_size,
+                                   const void *src, size_t src_size)
 {
     ssize_t ret;
     z_stream strm;
@@ -119,19 +121,19 @@  static ssize_t qcow2_compress(void *dest, size_t dest_size,
 }
 
 /*
- * qcow2_decompress()
+ * qcow2_zlib_decompress()
  *
  * Decompress some data (not more than @src_size bytes) to produce exactly
- * @dest_size bytes.
+ * @dest_size bytes using zlib compression method
  *
  * @dest - destination buffer, @dest_size bytes
  * @src - source buffer, @src_size bytes
  *
  * Returns: 0 on success
- *          -1 on fail
+ *          -EIO on failure
  */
-static ssize_t qcow2_decompress(void *dest, size_t dest_size,
-                                const void *src, size_t src_size)
+static ssize_t qcow2_zlib_decompress(void *dest, size_t dest_size,
+                                     const void *src, size_t src_size)
 {
     int ret = 0;
     z_stream strm;
@@ -144,7 +146,7 @@  static ssize_t qcow2_decompress(void *dest, size_t dest_size,
 
     ret = inflateInit2(&strm, -12);
     if (ret != Z_OK) {
-        return -1;
+        return -EIO;
     }
 
     ret = inflate(&strm, Z_FINISH);
@@ -154,7 +156,7 @@  static ssize_t qcow2_decompress(void *dest, size_t dest_size,
          * @src buffer may be processed partly (because in qcow2 we know size of
          * compressed data with precision of one sector)
          */
-        ret = -1;
+        ret = -EIO;
     }
 
     inflateEnd(&strm);
@@ -189,20 +191,67 @@  qcow2_co_do_compress(BlockDriverState *bs, void *dest, size_t dest_size,
     return arg.ret;
 }
 
+/*
+ * qcow2_co_compress()
+ *
+ * Compress @src_size bytes of data using the compression
+ * method defined by the image compression type
+ *
+ * @dest - destination buffer, @dest_size bytes
+ * @src - source buffer, @src_size bytes
+ *
+ * Returns: 0 on success
+ *          a negative error code on failure
+ */
 ssize_t coroutine_fn
 qcow2_co_compress(BlockDriverState *bs, void *dest, size_t dest_size,
                   const void *src, size_t src_size)
 {
-    return qcow2_co_do_compress(bs, dest, dest_size, src, src_size,
-                                qcow2_compress);
+    BDRVQcow2State *s = bs->opaque;
+    Qcow2CompressFunc fn;
+
+    switch (s->compression_type) {
+    case QCOW2_COMPRESSION_TYPE_ZLIB:
+        fn = qcow2_zlib_compress;
+        break;
+
+    default:
+        return -ENOTSUP;
+    }
+
+    return qcow2_co_do_compress(bs, dest, dest_size, src, src_size, fn);
 }
 
+/*
+ * qcow2_co_decompress()
+ *
+ * Decompress some data (not more than @src_size bytes) to produce exactly
+ * @dest_size bytes using the compression method defined by the image
+ * compression type
+ *
+ * @dest - destination buffer, @dest_size bytes
+ * @src - source buffer, @src_size bytes
+ *
+ * Returns: 0 on success
+ *          a negative error code on failure
+ */
 ssize_t coroutine_fn
 qcow2_co_decompress(BlockDriverState *bs, void *dest, size_t dest_size,
                     const void *src, size_t src_size)
 {
-    return qcow2_co_do_compress(bs, dest, dest_size, src, src_size,
-                                qcow2_decompress);
+    BDRVQcow2State *s = bs->opaque;
+    Qcow2CompressFunc fn;
+
+    switch (s->compression_type) {
+    case QCOW2_COMPRESSION_TYPE_ZLIB:
+        fn = qcow2_zlib_decompress;
+        break;
+
+    default:
+        return -ENOTSUP;
+    }
+
+    return qcow2_co_do_compress(bs, dest, dest_size, src, src_size, fn);
 }