Re: [PATCH v6 5/8] util: add Error object for qemu_open_internal error reporting

[Richard Henderson]

On 9/3/20 8:22 AM, Daniel P. Berrangé wrote:
> Instead of relying on the limited information from errno, we can now
> also provide detailed error messages to callers that ask for it.
> 
> Reviewed-by: Markus Armbruster 
> Signed-off-by: Daniel P. Berrangé 
> ---
>  util/osdep.c | 15 +--
>  1 file changed, 13 insertions(+), 2 deletions(-)

Reviewed-by: Richard Henderson 

r~

[PATCH v6 5/8] util: add Error object for qemu_open_internal error reporting

[Daniel P . Berrangé]

Instead of relying on the limited information from errno, we can now
also provide detailed error messages to callers that ask for it.

Reviewed-by: Markus Armbruster 
Signed-off-by: Daniel P. Berrangé 
---
 util/osdep.c | 15 +--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/util/osdep.c b/util/osdep.c
index 11531e8f59..28aa89adc9 100644
--- a/util/osdep.c
+++ b/util/osdep.c
@@ -22,6 +22,7 @@
  * THE SOFTWARE.
  */
 #include "qemu/osdep.h"
+#include "qapi/error.h"
 
 /* Needed early for CONFIG_BSD etc. */
 
@@ -297,7 +298,7 @@ static int qemu_open_cloexec(const char *name, int flags, 
mode_t mode)
  * Opens a file with FD_CLOEXEC set
  */
 static int
-qemu_open_internal(const char *name, int flags, mode_t mode)
+qemu_open_internal(const char *name, int flags, mode_t mode, Error **errp)
 {
 int ret;
 
@@ -311,12 +312,15 @@ qemu_open_internal(const char *name, int flags, mode_t 
mode)
 
 fdset_id = qemu_parse_fdset(fdset_id_str);
 if (fdset_id == -1) {
+error_setg(errp, "Could not parse fdset %s", name);
 errno = EINVAL;
 return -1;
 }
 
 dupfd = monitor_fdset_dup_fd_add(fdset_id, flags);
 if (dupfd == -1) {
+error_setg_errno(errp, errno, "Could not dup FD for %s flags %x",
+ name, flags);
 return -1;
 }
 
@@ -326,6 +330,13 @@ qemu_open_internal(const char *name, int flags, mode_t 
mode)
 
 ret = qemu_open_cloexec(name, flags, mode);
 
+if (ret == -1) {
+const char *action = flags & O_CREAT ? "create" : "open";
+error_setg_errno(errp, errno, "Could not %s '%s'",
+ action, name);
+}
+
+
 return ret;
 }
 
@@ -342,7 +353,7 @@ int qemu_open_old(const char *name, int flags, ...)
 }
 va_end(ap);
 
-ret = qemu_open_internal(name, flags, mode);
+ret = qemu_open_internal(name, flags, mode, NULL);
 
 #ifdef O_DIRECT
 if (ret == -1 && errno == EINVAL && (flags & O_DIRECT)) {
-- 
2.26.2