[Qemu-devel] [PATCH 2/6] block: make some functions public

[Dong Xu Wang]

In add-cow file format, we will use path_has_protocol and we will read
a NUL-terminated string from image , qed_read_string has done the samething,
so make the two functions public, then we will reuse them directly.

Signed-off-by: Dong Xu Wang <address@hidden>
---
 block.c     |   17 ++++++++++++++++-
 block.h     |    3 +++
 block/qed.c |   29 +----------------------------
 3 files changed, 20 insertions(+), 29 deletions(-)

diff --git a/block.c b/block.c
index 7547051..3cf5fe9 100644
--- a/block.c
+++ b/block.c
@@ -196,7 +196,7 @@ static void bdrv_io_limits_intercept(BlockDriverState *bs,
 }
 
 /* check if the path starts with "<protocol>:" */
-static int path_has_protocol(const char *path)
+int path_has_protocol(const char *path)
 {
     const char *p;
 
@@ -1606,6 +1606,21 @@ int bdrv_read(BlockDriverState *bs, int64_t sector_num,
     return bdrv_rw_co(bs, sector_num, buf, nb_sectors, false);
 }
 
+int bdrv_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;
+}
+
 #define BITS_PER_LONG  (sizeof(unsigned long) * 8)
 
 static void set_dirty_bitmap(BlockDriverState *bs, int64_t sector_num,
diff --git a/block.h b/block.h
index 7408acc..fd4f8cf 100644
--- a/block.h
+++ b/block.h
@@ -149,6 +149,8 @@ int bdrv_pwrite(BlockDriverState *bs, int64_t offset,
                 const void *buf, int count);
 int bdrv_pwrite_sync(BlockDriverState *bs, int64_t offset,
     const void *buf, int count);
+int bdrv_read_string(BlockDriverState *file, uint64_t offset, size_t n,
+                           char *buf, size_t buflen);
 int coroutine_fn bdrv_co_readv(BlockDriverState *bs, int64_t sector_num,
     int nb_sectors, QEMUIOVector *qiov);
 int coroutine_fn bdrv_co_copy_on_readv(BlockDriverState *bs,
@@ -321,6 +323,7 @@ char *bdrv_snapshot_dump(char *buf, int buf_size, 
QEMUSnapshotInfo *sn);
 
 char *get_human_readable_size(char *buf, int buf_size, int64_t size);
 int path_is_absolute(const char *path);
+int path_has_protocol(const char *path);
 void path_combine(char *dest, int dest_size,
                   const char *base_path,
                   const char *filename);
diff --git a/block/qed.c b/block/qed.c
index 30a31f9..b300584 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
@@ -437,7 +410,7 @@ static int bdrv_qed_open(BlockDriverState *bs, int flags)
             return -EINVAL;
         }
 
-        ret = qed_read_string(bs->file, s->header.backing_filename_offset,
+        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) {
-- 
1.7.1