crypto: Make block callbacks return 0 on success

They currently return the value of their headerlen/buflen parameter on
success. Returning 0 instead makes it clear that short reads/writes are
not possible.

Signed-off-by: Alberto Faria <afaria@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20220609152744.3891847-5-afaria@redhat.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Signed-off-by: Hanna Reitz <hreitz@redhat.com>

2 files changed, 37 insertions, 37 deletions

diff --git a/block/crypto.c b/block/crypto.c
index e7f5c4e31a..11c3ddbc73 100644
--- a/block/crypto.c
+++ b/block/crypto.c
@@ -55,12 +55,12 @@ static int block_crypto_probe_generic(QCryptoBlockFormat format,
 }
 
 
-static ssize_t block_crypto_read_func(QCryptoBlock *block,
-                                      size_t offset,
-                                      uint8_t *buf,
-                                      size_t buflen,
-                                      void *opaque,
-                                      Error **errp)
+static int block_crypto_read_func(QCryptoBlock *block,
+                                  size_t offset,
+                                  uint8_t *buf,
+                                  size_t buflen,
+                                  void *opaque,
+                                  Error **errp)
 {
     BlockDriverState *bs = opaque;
     ssize_t ret;
@@ -70,15 +70,15 @@ static ssize_t block_crypto_read_func(QCryptoBlock *block,
         error_setg_errno(errp, -ret, "Could not read encryption header");
         return ret;
     }
-    return buflen;
+    return 0;
 }
 
-static ssize_t block_crypto_write_func(QCryptoBlock *block,
-                                       size_t offset,
-                                       const uint8_t *buf,
-                                       size_t buflen,
-                                       void *opaque,
-                                       Error **errp)
+static int block_crypto_write_func(QCryptoBlock *block,
+                                   size_t offset,
+                                   const uint8_t *buf,
+                                   size_t buflen,
+                                   void *opaque,
+                                   Error **errp)
 {
     BlockDriverState *bs = opaque;
     ssize_t ret;
@@ -88,7 +88,7 @@ static ssize_t block_crypto_write_func(QCryptoBlock *block,
         error_setg_errno(errp, -ret, "Could not write encryption header");
         return ret;
     }
-    return buflen;
+    return 0;
 }
 
 
@@ -99,12 +99,12 @@ struct BlockCryptoCreateData {
 };
 
 
-static ssize_t block_crypto_create_write_func(QCryptoBlock *block,
-                                              size_t offset,
-                                              const uint8_t *buf,
-                                              size_t buflen,
-                                              void *opaque,
-                                              Error **errp)
+static int block_crypto_create_write_func(QCryptoBlock *block,
+                                          size_t offset,
+                                          const uint8_t *buf,
+                                          size_t buflen,
+                                          void *opaque,
+                                          Error **errp)
 {
     struct BlockCryptoCreateData *data = opaque;
     ssize_t ret;
@@ -114,13 +114,13 @@ static ssize_t block_crypto_create_write_func(QCryptoBlock *block,
         error_setg_errno(errp, -ret, "Could not write encryption header");
         return ret;
     }
-    return ret;
+    return 0;
 }
 
-static ssize_t block_crypto_create_init_func(QCryptoBlock *block,
-                                             size_t headerlen,
-                                             void *opaque,
-                                             Error **errp)
+static int block_crypto_create_init_func(QCryptoBlock *block,
+                                         size_t headerlen,
+                                         void *opaque,
+                                         Error **errp)
 {
     struct BlockCryptoCreateData *data = opaque;
     Error *local_error = NULL;
@@ -139,7 +139,7 @@ static ssize_t block_crypto_create_init_func(QCryptoBlock *block,
                        data->prealloc, 0, &local_error);
 
     if (ret >= 0) {
-        return ret;
+        return 0;
     }
 
 error:
diff --git a/block/qcow2.c b/block/qcow2.c
index d5a1e8bc43..c43238a006 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -94,9 +94,9 @@ static int qcow2_probe(const uint8_t *buf, int buf_size, const char *filename)
 }
 
 
-static ssize_t qcow2_crypto_hdr_read_func(QCryptoBlock *block, size_t offset,
-                                          uint8_t *buf, size_t buflen,
-                                          void *opaque, Error **errp)
+static int qcow2_crypto_hdr_read_func(QCryptoBlock *block, size_t offset,
+                                      uint8_t *buf, size_t buflen,
+                                      void *opaque, Error **errp)
 {
     BlockDriverState *bs = opaque;
     BDRVQcow2State *s = bs->opaque;
@@ -113,12 +113,12 @@ static ssize_t qcow2_crypto_hdr_read_func(QCryptoBlock *block, size_t offset,
         error_setg_errno(errp, -ret, "Could not read encryption header");
         return -1;
     }
-    return buflen;
+    return 0;
 }
 
 
-static ssize_t qcow2_crypto_hdr_init_func(QCryptoBlock *block, size_t headerlen,
-                                          void *opaque, Error **errp)
+static int qcow2_crypto_hdr_init_func(QCryptoBlock *block, size_t headerlen,
+                                      void *opaque, Error **errp)
 {
     BlockDriverState *bs = opaque;
     BDRVQcow2State *s = bs->opaque;
@@ -151,13 +151,13 @@ static ssize_t qcow2_crypto_hdr_init_func(QCryptoBlock *block, size_t headerlen,
         return -1;
     }
 
-    return ret;
+    return 0;
 }
 
 
-static ssize_t qcow2_crypto_hdr_write_func(QCryptoBlock *block, size_t offset,
-                                           const uint8_t *buf, size_t buflen,
-                                           void *opaque, Error **errp)
+static int qcow2_crypto_hdr_write_func(QCryptoBlock *block, size_t offset,
+                                       const uint8_t *buf, size_t buflen,
+                                       void *opaque, Error **errp)
 {
     BlockDriverState *bs = opaque;
     BDRVQcow2State *s = bs->opaque;
@@ -174,7 +174,7 @@ static ssize_t qcow2_crypto_hdr_write_func(QCryptoBlock *block, size_t offset,
         error_setg_errno(errp, -ret, "Could not read encryption header");
         return -1;
     }
-    return buflen;
+    return 0;
 }
 
 static QDict*