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[PATCH v5 5/8] util: add Error object for qemu_open_internal error reporting

Daniel P. Berrangé posted 8 patches 5 years, 2 months ago
There is a newer version of this series
[PATCH v5 5/8] util: add Error object for qemu_open_internal error reporting
Posted by Daniel P. Berrangé 5 years, 2 months ago 
Instead of relying on the limited information from errno, we can now
also provide detailed error messages to callers that ask for it.

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
---
 util/osdep.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/util/osdep.c b/util/osdep.c
index dd34b58bb7..28aa89adc9 100644
--- a/util/osdep.c
+++ b/util/osdep.c
@@ -298,7 +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;
 
@@ -312,12 +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;
         }
 
@@ -327,6 +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;
 }
 
@@ -343,7 +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
Re: [PATCH v5 5/8] util: add Error object for qemu_open_internal error reporting
Posted by Markus Armbruster 5 years, 2 months ago 
Daniel P. Berrangé <berrange@redhat.com> writes:

> Instead of relying on the limited information from errno, we can now
> also provide detailed error messages to callers that ask for it.
>
> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
> ---
>  util/osdep.c | 14 ++++++++++++--
>  1 file changed, 12 insertions(+), 2 deletions(-)
>
> diff --git a/util/osdep.c b/util/osdep.c
> index dd34b58bb7..28aa89adc9 100644
> --- a/util/osdep.c
> +++ b/util/osdep.c
> @@ -298,7 +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;
>  
> @@ -312,12 +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);

You kept the reporting of flags here.  Intentional?

>              return -1;
>          }
>  
> @@ -327,6 +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;
>  }

Much neater.  Thanks!

>  
> @@ -343,7 +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)) {

Reviewed-by: Markus Armbruster <armbru@redhat.com>
Re: [PATCH v5 5/8] util: add Error object for qemu_open_internal error reporting
Posted by Daniel P. Berrangé 5 years, 2 months ago 
On Thu, Sep 03, 2020 at 11:03:52AM +0200, Markus Armbruster wrote:
> Daniel P. Berrangé <berrange@redhat.com> writes:
> 
> > Instead of relying on the limited information from errno, we can now
> > also provide detailed error messages to callers that ask for it.
> >
> > Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
> > ---
> >  util/osdep.c | 14 ++++++++++++--
> >  1 file changed, 12 insertions(+), 2 deletions(-)
> >
> > diff --git a/util/osdep.c b/util/osdep.c
> > index dd34b58bb7..28aa89adc9 100644
> > --- a/util/osdep.c
> > +++ b/util/osdep.c
> > @@ -298,7 +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;
> >  
> > @@ -312,12 +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);
> 
> You kept the reporting of flags here.  Intentional?

I think it is useful because one of the failure reasons for
monitor_fdset_dup_fd_add is mis-matching flags. So if we ever
get a bug report mentioning this error message it'd be useful
to have the flags present.

> > @@ -343,7 +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)) {
> 
> Reviewed-by: Markus Armbruster <armbru@redhat.com>

Regards,
Daniel
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