nbd: Move nbd_errno_to_system_errno() to public header

This is needed in preparation for structured reply handling,
as we will be performing the translation from NBD error to
system errno value higher in the stack at block/nbd-client.c.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20171027104037.8319-3-eblake@redhat.com>

4 files changed, 37 insertions, 45 deletions

diff --git a/nbd/client.c b/nbd/client.c
index 59d7c9d..50f36b5 100644
--- a/nbd/client.c
+++ b/nbd/client.c
@@ -22,38 +22,6 @@
 #include "trace.h"
 #include "nbd-internal.h"
 
-static int nbd_errno_to_system_errno(int err)
-{
-    int ret;
-    switch (err) {
-    case NBD_SUCCESS:
-        ret = 0;
-        break;
-    case NBD_EPERM:
-        ret = EPERM;
-        break;
-    case NBD_EIO:
-        ret = EIO;
-        break;
-    case NBD_ENOMEM:
-        ret = ENOMEM;
-        break;
-    case NBD_ENOSPC:
-        ret = ENOSPC;
-        break;
-    case NBD_ESHUTDOWN:
-        ret = ESHUTDOWN;
-        break;
-    default:
-        trace_nbd_unknown_error(err);
-        /* fallthrough */
-    case NBD_EINVAL:
-        ret = EINVAL;
-        break;
-    }
-    return ret;
-}
-
 /* Definitions for opaque data types */
 
 static QTAILQ_HEAD(, NBDExport) exports = QTAILQ_HEAD_INITIALIZER(exports);
diff --git a/nbd/common.c b/nbd/common.c
index 7456021..593904f 100644
--- a/nbd/common.c
+++ b/nbd/common.c
@@ -18,6 +18,7 @@
 
 #include "qemu/osdep.h"
 #include "qapi/error.h"
+#include "trace.h"
 #include "nbd-internal.h"
 
 /* Discard length bytes from channel.  Return -errno on failure and 0 on
@@ -171,3 +172,36 @@ const char *nbd_err_lookup(int err)
         return "<unknown>";
     }
 }
+
+
+int nbd_errno_to_system_errno(int err)
+{
+    int ret;
+    switch (err) {
+    case NBD_SUCCESS:
+        ret = 0;
+        break;
+    case NBD_EPERM:
+        ret = EPERM;
+        break;
+    case NBD_EIO:
+        ret = EIO;
+        break;
+    case NBD_ENOMEM:
+        ret = ENOMEM;
+        break;
+    case NBD_ENOSPC:
+        ret = ENOSPC;
+        break;
+    case NBD_ESHUTDOWN:
+        ret = ESHUTDOWN;
+        break;
+    default:
+        trace_nbd_unknown_error(err);
+        /* fallthrough */
+    case NBD_EINVAL:
+        ret = EINVAL;
+        break;
+    }
+    return ret;
+}
diff --git a/nbd/nbd-internal.h b/nbd/nbd-internal.h
index 4bfe5be..df6c8b2 100644
--- a/nbd/nbd-internal.h
+++ b/nbd/nbd-internal.h
@@ -64,18 +64,6 @@
 #define NBD_SET_TIMEOUT             _IO(0xab, 9)
 #define NBD_SET_FLAGS               _IO(0xab, 10)
 
-/* NBD errors are based on errno numbers, so there is a 1:1 mapping,
- * but only a limited set of errno values is specified in the protocol.
- * Everything else is squashed to EINVAL.
- */
-#define NBD_SUCCESS    0
-#define NBD_EPERM      1
-#define NBD_EIO        5
-#define NBD_ENOMEM     12
-#define NBD_EINVAL     22
-#define NBD_ENOSPC     28
-#define NBD_ESHUTDOWN  108
-
 /* nbd_read_eof
  * Tries to read @size bytes from @ioc.
  * Returns 1 on success
diff --git a/nbd/trace-events b/nbd/trace-events
index 920c8a0..ab3d7da 100644
--- a/nbd/trace-events
+++ b/nbd/trace-events
@@ -1,5 +1,4 @@
 # nbd/client.c
-nbd_unknown_error(int err) "Squashing unexpected error %d to EINVAL"
 nbd_send_option_request(uint32_t opt, const char *name, uint32_t len) "Sending option request %" PRIu32" (%s), len %" PRIu32
 nbd_receive_option_reply(uint32_t option, const char *optname, uint32_t type, const char *typename, uint32_t length) "Received option reply 0x%" PRIx32" (%s), type 0x%" PRIx32" (%s), len %" PRIu32
 nbd_reply_err_unsup(uint32_t option, const char *name) "server doesn't understand request 0x%" PRIx32 " (%s), attempting fallback"
@@ -31,6 +30,9 @@ nbd_client_clear_socket(void) "Clearing NBD socket"
 nbd_send_request(uint64_t from, uint32_t len, uint64_t handle, uint16_t flags, uint16_t type, const char *name) "Sending request to server: { .from = %" PRIu64", .len = %" PRIu32 ", .handle = %" PRIu64 ", .flags = 0x%" PRIx16 ", .type = %" PRIu16 " (%s) }"
 nbd_receive_reply(uint32_t magic, int32_t error, const char *errname, uint64_t handle) "Got reply: { magic = 0x%" PRIx32 ", .error = %" PRId32 " (%s), handle = %" PRIu64" }"
 
+# nbd/common.c
+nbd_unknown_error(int err) "Squashing unexpected error %d to EINVAL"
+
 # nbd/server.c
 nbd_negotiate_send_rep_len(uint32_t opt, const char *optname, uint32_t type, const char *typename, uint32_t len) "Reply opt=0x%" PRIx32 " (%s), type=0x%" PRIx32 " (%s), len=%" PRIu32
 nbd_negotiate_send_rep_err(const char *msg) "sending error message \"%s\""