[Qemu-devel] [PATCH v2 0/9] QMP/HMP: add error reason to open failures

[Qemu-devel] [PATCH v2 0/9] QMP/HMP: add error reason to open failures

[Luiz Capitulino]

I was surprised to find out that we still have old users of
QERR_OPEN_FILE_FAILED that print errors like:

(qemu) dump-guest-memory -p /lkmads/foo
Could not open '/lkmads/foo'
(qemu)

This series converts all those users to a new helper called
error_setg_file_open(), which adds error reason to open failures:

(qemu) dump-guest-memory -p /sfmdkjf/foo
Could not open '/sfmdkjf/foo': No such file or directory
(qemu) 

v2

 - bdrv_reopen_prepare(): use generic error message
 - s/error/-ret for bdrv_open() errors

Luiz Capitulino (9):
  error: add error_setg_file_open() helper
  rng-random: use error_setg_file_open()
  block: mirror_complete(): use error_setg_file_open()
  blockdev: use error_setg_file_open()
  cpus: use error_setg_file_open()
  dump: qmp_dump_guest_memory(): use error_setg_file_open()
  savevm: qmp_xen_save_devices_state(): use error_setg_file_open()
  block: bdrv_reopen_prepare(): don't use QERR_OPEN_FILE_FAILED
  qerror: drop QERR_OPEN_FILE_FAILED macro

 backends/rng-random.c     |  3 +--
 block.c                   |  4 ++--
 block/mirror.c            |  2 +-
 blockdev.c                | 11 +++++++----
 cpus.c                    |  4 ++--
 dump.c                    |  2 +-
 include/qapi/error.h      |  5 +++++
 include/qapi/qmp/qerror.h |  3 ---
 savevm.c                  |  2 +-
 util/error.c              |  5 +++++
 10 files changed, 25 insertions(+), 16 deletions(-)

-- 
1.8.1.4

[Qemu-devel] [PATCH 1/9] error: add error_setg_file_open() helper

[Luiz Capitulino]

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
---
 include/qapi/error.h | 5 +++++
 util/error.c         | 5 +++++
 2 files changed, 10 insertions(+)

diff --git a/include/qapi/error.h b/include/qapi/error.h
index 5cd2f0c..ffd1cea 100644
--- a/include/qapi/error.h
+++ b/include/qapi/error.h
@@ -45,6 +45,11 @@ void error_set_errno(Error **err, int os_error, ErrorClass err_class, const char
     error_set_errno(err, os_error, ERROR_CLASS_GENERIC_ERROR, fmt, ## __VA_ARGS__)
 
 /**
+ * Helper for open() errors
+ */
+void error_setg_file_open(Error **errp, int os_errno, const char *filename);
+
+/**
  * Returns true if an indirect pointer to an error is pointing to a valid
  * error object.
  */
diff --git a/util/error.c b/util/error.c
index 519f6b6..53b0435 100644
--- a/util/error.c
+++ b/util/error.c
@@ -71,6 +71,11 @@ void error_set_errno(Error **errp, int os_errno, ErrorClass err_class,
     *errp = err;
 }
 
+void error_setg_file_open(Error **errp, int os_errno, const char *filename)
+{
+    error_setg_errno(errp, os_errno, "Could not open '%s'", filename);
+}
+
 Error *error_copy(const Error *err)
 {
     Error *err_new;
-- 
1.8.1.4

[Qemu-devel] [PATCH 2/9] rng-random: use error_setg_file_open()

[Luiz Capitulino]

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
---
 backends/rng-random.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/backends/rng-random.c b/backends/rng-random.c
index 830360c..68dfc8a 100644
--- a/backends/rng-random.c
+++ b/backends/rng-random.c
@@ -78,9 +78,8 @@ static void rng_random_opened(RngBackend *b, Error **errp)
                   "filename", "a valid filename");
     } else {
         s->fd = qemu_open(s->filename, O_RDONLY | O_NONBLOCK);
-
         if (s->fd == -1) {
-            error_set(errp, QERR_OPEN_FILE_FAILED, s->filename);
+            error_setg_file_open(errp, errno, s->filename);
         }
     }
 }
-- 
1.8.1.4

[Qemu-devel] [PATCH 3/9] block: mirror_complete(): use error_setg_file_open()

[Luiz Capitulino]

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
---
 block/mirror.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/block/mirror.c b/block/mirror.c
index 8b07dec..1ae724f 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -512,7 +512,7 @@ static void mirror_complete(BlockJob *job, Error **errp)
         char backing_filename[PATH_MAX];
         bdrv_get_full_backing_filename(s->target, backing_filename,
                                        sizeof(backing_filename));
-        error_set(errp, QERR_OPEN_FILE_FAILED, backing_filename);
+        error_setg_file_open(errp, -ret, backing_filename);
         return;
     }
     if (!s->synced) {
-- 
1.8.1.4

[Qemu-devel] [PATCH 4/9] blockdev: use error_setg_file_open()

[Luiz Capitulino]

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
---
 blockdev.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/blockdev.c b/blockdev.c
index 9937311..5975dde 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -899,7 +899,7 @@ static void external_snapshot_prepare(BlkTransactionStates *common,
     ret = bdrv_open(states->new_bs, new_image_file, NULL,
                     flags | BDRV_O_NO_BACKING, drv);
     if (ret != 0) {
-        error_set(errp, QERR_OPEN_FILE_FAILED, new_image_file);
+        error_setg_file_open(errp, -ret, new_image_file);
     }
 }
 
@@ -1062,8 +1062,11 @@ static void qmp_bdrv_open_encrypted(BlockDriverState *bs, const char *filename,
                                     int bdrv_flags, BlockDriver *drv,
                                     const char *password, Error **errp)
 {
-    if (bdrv_open(bs, filename, NULL, bdrv_flags, drv) < 0) {
-        error_set(errp, QERR_OPEN_FILE_FAILED, filename);
+    int ret;
+
+    ret = bdrv_open(bs, filename, NULL, bdrv_flags, drv);
+    if (ret < 0) {
+        error_setg_file_open(errp, -ret, filename);
         return;
     }
 
@@ -1483,7 +1486,7 @@ void qmp_drive_mirror(const char *device, const char *target,
 
     if (ret < 0) {
         bdrv_delete(target_bs);
-        error_set(errp, QERR_OPEN_FILE_FAILED, target);
+        error_setg_file_open(errp, -ret, target);
         return;
     }
 
-- 
1.8.1.4

[Qemu-devel] [PATCH 5/9] cpus: use error_setg_file_open()

[Luiz Capitulino]

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
---
 cpus.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/cpus.c b/cpus.c
index c232265..c8bc8ad 100644
--- a/cpus.c
+++ b/cpus.c
@@ -1278,7 +1278,7 @@ void qmp_memsave(int64_t addr, int64_t size, const char *filename,
 
     f = fopen(filename, "wb");
     if (!f) {
-        error_set(errp, QERR_OPEN_FILE_FAILED, filename);
+        error_setg_file_open(errp, errno, filename);
         return;
     }
 
@@ -1308,7 +1308,7 @@ void qmp_pmemsave(int64_t addr, int64_t size, const char *filename,
 
     f = fopen(filename, "wb");
     if (!f) {
-        error_set(errp, QERR_OPEN_FILE_FAILED, filename);
+        error_setg_file_open(errp, errno, filename);
         return;
     }
 
-- 
1.8.1.4

[Qemu-devel] [PATCH 6/9] dump: qmp_dump_guest_memory(): use error_setg_file_open()

[Luiz Capitulino]

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
---
 dump.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/dump.c b/dump.c
index c0d3da5..28fd296 100644
--- a/dump.c
+++ b/dump.c
@@ -847,7 +847,7 @@ void qmp_dump_guest_memory(bool paging, const char *file, bool has_begin,
     if  (strstart(file, "file:", &p)) {
         fd = qemu_open(p, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, S_IRUSR);
         if (fd < 0) {
-            error_set(errp, QERR_OPEN_FILE_FAILED, p);
+            error_setg_file_open(errp, errno, p);
             return;
         }
     }
-- 
1.8.1.4

[Qemu-devel] [PATCH 7/9] savevm: qmp_xen_save_devices_state(): use error_setg_file_open()

[Luiz Capitulino]

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
---
 savevm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/savevm.c b/savevm.c
index 2ce439f..ff5ece6 100644
--- a/savevm.c
+++ b/savevm.c
@@ -2410,7 +2410,7 @@ void qmp_xen_save_devices_state(const char *filename, Error **errp)
 
     f = qemu_fopen(filename, "wb");
     if (!f) {
-        error_set(errp, QERR_OPEN_FILE_FAILED, filename);
+        error_setg_file_open(errp, errno, filename);
         goto the_end;
     }
     ret = qemu_save_device_state(f);
-- 
1.8.1.4

[Qemu-devel] [PATCH 8/9] block: bdrv_reopen_prepare(): don't use QERR_OPEN_FILE_FAILED

[Luiz Capitulino]

The call to drv->bdrv_reopen_prepare() can fail due to reasons
other than an open failure. Unfortunately, we can't use errno
nor -ret, cause they are not always set.

Stick to a generic error message then.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
---
 block.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/block.c b/block.c
index 79ad33d..b88ad2f 100644
--- a/block.c
+++ b/block.c
@@ -1291,8 +1291,8 @@ int bdrv_reopen_prepare(BDRVReopenState *reopen_state, BlockReopenQueue *queue,
             if (local_err != NULL) {
                 error_propagate(errp, local_err);
             } else {
-                error_set(errp, QERR_OPEN_FILE_FAILED,
-                          reopen_state->bs->filename);
+                error_setg(errp, "failed while preparing to reopen image '%s'",
+                           reopen_state->bs->filename);
             }
             goto error;
         }
-- 
1.8.1.4

[Qemu-devel] [PATCH 9/9] qerror: drop QERR_OPEN_FILE_FAILED macro

[Luiz Capitulino]

Not used since the last commit.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
---
 include/qapi/qmp/qerror.h | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/include/qapi/qmp/qerror.h b/include/qapi/qmp/qerror.h
index 6c0a18d..c30c2f6 100644
--- a/include/qapi/qmp/qerror.h
+++ b/include/qapi/qmp/qerror.h
@@ -177,9 +177,6 @@ void assert_no_error(Error *err);
 #define QERR_NOT_SUPPORTED \
     ERROR_CLASS_GENERIC_ERROR, "Not supported"
 
-#define QERR_OPEN_FILE_FAILED \
-    ERROR_CLASS_GENERIC_ERROR, "Could not open '%s'"
-
 #define QERR_PERMISSION_DENIED \
     ERROR_CLASS_GENERIC_ERROR, "Insufficient permission to perform this operation"
 
-- 
1.8.1.4

Re: [Qemu-devel] [PATCH v2 0/9] QMP/HMP: add error reason to open failures

[Stefan Hajnoczi]

On Mon, Jun 10, 2013 at 01:02:19PM -0400, Luiz Capitulino wrote:
> I was surprised to find out that we still have old users of
> QERR_OPEN_FILE_FAILED that print errors like:
> 
> (qemu) dump-guest-memory -p /lkmads/foo
> Could not open '/lkmads/foo'
> (qemu)
> 
> This series converts all those users to a new helper called
> error_setg_file_open(), which adds error reason to open failures:
> 
> (qemu) dump-guest-memory -p /sfmdkjf/foo
> Could not open '/sfmdkjf/foo': No such file or directory
> (qemu) 
> 
> v2
> 
>  - bdrv_reopen_prepare(): use generic error message
>  - s/error/-ret for bdrv_open() errors
> 
> Luiz Capitulino (9):
>   error: add error_setg_file_open() helper
>   rng-random: use error_setg_file_open()
>   block: mirror_complete(): use error_setg_file_open()
>   blockdev: use error_setg_file_open()
>   cpus: use error_setg_file_open()
>   dump: qmp_dump_guest_memory(): use error_setg_file_open()
>   savevm: qmp_xen_save_devices_state(): use error_setg_file_open()
>   block: bdrv_reopen_prepare(): don't use QERR_OPEN_FILE_FAILED
>   qerror: drop QERR_OPEN_FILE_FAILED macro
> 
>  backends/rng-random.c     |  3 +--
>  block.c                   |  4 ++--
>  block/mirror.c            |  2 +-
>  blockdev.c                | 11 +++++++----
>  cpus.c                    |  4 ++--
>  dump.c                    |  2 +-
>  include/qapi/error.h      |  5 +++++
>  include/qapi/qmp/qerror.h |  3 ---
>  savevm.c                  |  2 +-
>  util/error.c              |  5 +++++
>  10 files changed, 25 insertions(+), 16 deletions(-)
> 
> -- 
> 1.8.1.4
> 

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>

Re: [Qemu-devel] [PATCH v2 0/9] QMP/HMP: add error reason to open failures

[Stefan Hajnoczi]

On Mon, Jun 10, 2013 at 01:02:19PM -0400, Luiz Capitulino wrote:
I should have qualified by Reviewed-by: with "reviewed block layer changes".

Stefan

Re: [Qemu-devel] [PATCH 8/9] block: bdrv_reopen_prepare(): don't use QERR_OPEN_FILE_FAILED

[Kevin Wolf]

Am 10.06.2013 um 19:02 hat Luiz Capitulino geschrieben:
> The call to drv->bdrv_reopen_prepare() can fail due to reasons
> other than an open failure. Unfortunately, we can't use errno
> nor -ret, cause they are not always set.
> 
> Stick to a generic error message then.
> 
> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
> ---
>  block.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/block.c b/block.c
> index 79ad33d..b88ad2f 100644
> --- a/block.c
> +++ b/block.c
> @@ -1291,8 +1291,8 @@ int bdrv_reopen_prepare(BDRVReopenState *reopen_state, BlockReopenQueue *queue,
>              if (local_err != NULL) {
>                  error_propagate(errp, local_err);
>              } else {
> -                error_set(errp, QERR_OPEN_FILE_FAILED,
> -                          reopen_state->bs->filename);
> +                error_setg(errp, "failed while preparing to reopen image '%s'",

Please start the message with an uppercase letter like before.

Also, maybe "Failed to prepare for reopening '%s'" is better?

> +                           reopen_state->bs->filename);
>              }
>              goto error;
>          }

Kevin

Re: [Qemu-devel] [PATCH v2 0/9] QMP/HMP: add error reason to open failures

[Kevin Wolf]

Am 10.06.2013 um 19:02 hat Luiz Capitulino geschrieben:
> I was surprised to find out that we still have old users of
> QERR_OPEN_FILE_FAILED that print errors like:
> 
> (qemu) dump-guest-memory -p /lkmads/foo
> Could not open '/lkmads/foo'
> (qemu)
> 
> This series converts all those users to a new helper called
> error_setg_file_open(), which adds error reason to open failures:
> 
> (qemu) dump-guest-memory -p /sfmdkjf/foo
> Could not open '/sfmdkjf/foo': No such file or directory
> (qemu) 
> 
> v2
> 
>  - bdrv_reopen_prepare(): use generic error message
>  - s/error/-ret for bdrv_open() errors

I suggested an error message change in patch 8, but I think that's minor
enough that you don't have to resend the series after changing the text.
So you can add:

Acked-by: Kevin Wolf <kwolf@redhat.com>

Re: [Qemu-devel] [PATCH v2 0/9] QMP/HMP: add error reason to open failures

[Luiz Capitulino]

On Tue, 11 Jun 2013 09:44:08 +0200
Stefan Hajnoczi <stefanha@gmail.com> wrote:

> On Mon, Jun 10, 2013 at 01:02:19PM -0400, Luiz Capitulino wrote:
> I should have qualified by Reviewed-by: with "reviewed block layer changes".

I've added it only to the block layer patches.

Re: [Qemu-devel] [PATCH 8/9] block: bdrv_reopen_prepare(): don't use QERR_OPEN_FILE_FAILED

[Luiz Capitulino]

On Tue, 11 Jun 2013 10:38:47 +0200
Kevin Wolf <kwolf@redhat.com> wrote:

> Am 10.06.2013 um 19:02 hat Luiz Capitulino geschrieben:
> > The call to drv->bdrv_reopen_prepare() can fail due to reasons
> > other than an open failure. Unfortunately, we can't use errno
> > nor -ret, cause they are not always set.
> > 
> > Stick to a generic error message then.
> > 
> > Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
> > ---
> >  block.c | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> > 
> > diff --git a/block.c b/block.c
> > index 79ad33d..b88ad2f 100644
> > --- a/block.c
> > +++ b/block.c
> > @@ -1291,8 +1291,8 @@ int bdrv_reopen_prepare(BDRVReopenState *reopen_state, BlockReopenQueue *queue,
> >              if (local_err != NULL) {
> >                  error_propagate(errp, local_err);
> >              } else {
> > -                error_set(errp, QERR_OPEN_FILE_FAILED,
> > -                          reopen_state->bs->filename);
> > +                error_setg(errp, "failed while preparing to reopen image '%s'",
> 
> Please start the message with an uppercase letter like before.

Fixed.

> Also, maybe "Failed to prepare for reopening '%s'" is better?

I have no idea :)