[Qemu-devel] [PATCH V20 3/8] qed_read_string to bdrv_read_string

[Dong Xu Wang]

Make qed_read_string function to a common interface, so move it to
block.c.

Signed-off-by: Dong Xu Wang <address@hidden>
---
 block.c               | 27 +++++++++++++++++++++++++++
 block/qed.c           | 34 ++++------------------------------
 include/block/block.h |  2 ++
 3 files changed, 33 insertions(+), 30 deletions(-)

diff --git a/block.c b/block.c
index b2711e9..e747afb 100644
--- a/block.c
+++ b/block.c
@@ -206,6 +206,33 @@ int path_has_protocol(const char *path)
     return *p == ':';
 }
 
+/**
+ * Read a string of known length from the image file
+ *
+ * @bs:         Image file
+ * @offset:     File offset to start of string, in bytes
+ * @n:          String length in bytes
+ * @buf:        Destination buffer
+ * @buflen:     Destination buffer length in bytes
+ * @ret:        0 on success, -errno on failure
+ *
+ * The string is NUL-terminated.
+ */
+int bdrv_read_string(BlockDriverState *bs, uint64_t offset, size_t n,
+                     char *buf, size_t buflen)
+{
+    int ret;
+    if (n >= buflen) {
+        return -EINVAL;
+    }
+    ret = bdrv_pread(bs, offset, buf, n);
+    if (ret < 0) {
+        return ret;
+    }
+    buf[n] = '\0';
+    return 0;
+}
+
 int path_is_absolute(const char *path)
 {
 #ifdef _WIN32
diff --git a/block/qed.c b/block/qed.c
index 6b02c47..09cc13f 100644
--- a/block/qed.c
+++ b/block/qed.c
@@ -217,33 +217,6 @@ static bool qed_is_image_size_valid(uint64_t image_size, 
uint32_t cluster_size,
 }
 
 /**
- * Read a string of known length from the image file
- *
- * @file:       Image file
- * @offset:     File offset to start of string, in bytes
- * @n:          String length in bytes
- * @buf:        Destination buffer
- * @buflen:     Destination buffer length in bytes
- * @ret:        0 on success, -errno on failure
- *
- * The string is NUL-terminated.
- */
-static int qed_read_string(BlockDriverState *file, uint64_t offset, size_t n,
-                           char *buf, size_t buflen)
-{
-    int ret;
-    if (n >= buflen) {
-        return -EINVAL;
-    }
-    ret = bdrv_pread(file, offset, buf, n);
-    if (ret < 0) {
-        return ret;
-    }
-    buf[n] = '\0';
-    return 0;
-}
-
-/**
  * Allocate new clusters
  *
  * @s:          QED state
@@ -437,9 +410,10 @@ static int bdrv_qed_open(BlockDriverState *bs, QDict 
*options, int flags)
             return -EINVAL;
         }
 
-        ret = qed_read_string(bs->file, s->header.backing_filename_offset,
-                              s->header.backing_filename_size, 
bs->backing_file,
-                              sizeof(bs->backing_file));
+        ret = bdrv_read_string(bs->file, s->header.backing_filename_offset,
+                               s->header.backing_filename_size,
+                               bs->backing_file,
+                               sizeof(bs->backing_file));
         if (ret < 0) {
             return ret;
         }
diff --git a/include/block/block.h b/include/block/block.h
index f025185..30c8e1a 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -168,6 +168,8 @@ int bdrv_pwrite_sync(BlockDriverState *bs, int64_t offset,
     const void *buf, int count);
 int coroutine_fn bdrv_co_readv(BlockDriverState *bs, int64_t sector_num,
     int nb_sectors, QEMUIOVector *qiov);
+int bdrv_read_string(BlockDriverState *bs, uint64_t offset, size_t n,
+                     char *buf, size_t buflen);
 int coroutine_fn bdrv_co_copy_on_readv(BlockDriverState *bs,
     int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
 int coroutine_fn bdrv_co_writev(BlockDriverState *bs, int64_t sector_num,
-- 
1.7.11.7