Re: [Qemu-devel] [PATCH 3/9] block: bdrv_reopen_prepare(): use error_setg_file_open()
On Fri, Jun 07, 2013 at 03:52:29PM -0400, Luiz Capitulino wrote:
Signed-off-by: Luiz Capitulino lcapitul...@redhat.com
---
block.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/block.c b/block.c
index 79ad33d..c78f152 100644
--- a/block.c
+++ b/block.c
@@ -1291,8 +1291,7 @@ 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_file_open(errp, errno,
reopen_state-bs-filename);
s/errno/-ret/
Re: [Qemu-devel] [PATCH 3/9] block: bdrv_reopen_prepare(): use error_setg_file_open()
On Fri, Jun 07, 2013 at 03:52:29PM -0400, Luiz Capitulino wrote:
Signed-off-by: Luiz Capitulino lcapitul...@redhat.com
---
block.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/block.c b/block.c
index 79ad33d..c78f152 100644
--- a/block.c
+++ b/block.c
@@ -1291,8 +1291,7 @@ 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_file_open(errp, errno,
reopen_state-bs-filename);
Looking closer, my suggestion was wrong too.
I think QERR_OPEN_FILE_FAILED is simply the wrong error here. We don't
know that the error occurred when trying to open a file.
errno does not necessarily contain the error value!
Stefan
Re: [Qemu-devel] [PATCH 3/9] block: bdrv_reopen_prepare(): use error_setg_file_open()
On Mon, 10 Jun 2013 10:43:47 +0200
Stefan Hajnoczi stefa...@gmail.com wrote:
On Fri, Jun 07, 2013 at 03:52:29PM -0400, Luiz Capitulino wrote:
Signed-off-by: Luiz Capitulino lcapitul...@redhat.com
---
block.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/block.c b/block.c
index 79ad33d..c78f152 100644
--- a/block.c
+++ b/block.c
@@ -1291,8 +1291,7 @@ 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_file_open(errp, errno,
reopen_state-bs-filename);
Looking closer, my suggestion was wrong too.
I think QERR_OPEN_FILE_FAILED is simply the wrong error here. We don't
know that the error occurred when trying to open a file.
Right.
errno does not necessarily contain the error value!
There are two ways to fix it (and they're not mutually exclusive):
1. We could review all bdrv_reopen_prepare() methods and make sure they
set errno on failure
2. We set errno=0 before calling the bdrv_reopen_prepare() method and if
there's an error and if errno != 0 we use it, otherwise we set a generic
failed to prepare to reopen image error
Option 1 goes a bit beyond the time I'd like to spent on this series.
Option 2 is quite reasonable.
What do you think?
Re: [Qemu-devel] [PATCH 3/9] block: bdrv_reopen_prepare(): use error_setg_file_open()
Am 10.06.2013 um 15:21 hat Luiz Capitulino geschrieben:
On Mon, 10 Jun 2013 10:43:47 +0200
Stefan Hajnoczi stefa...@gmail.com wrote:
On Fri, Jun 07, 2013 at 03:52:29PM -0400, Luiz Capitulino wrote:
Signed-off-by: Luiz Capitulino lcapitul...@redhat.com
---
block.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/block.c b/block.c
index 79ad33d..c78f152 100644
--- a/block.c
+++ b/block.c
@@ -1291,8 +1291,7 @@ 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_file_open(errp, errno,
reopen_state-bs-filename);
Looking closer, my suggestion was wrong too.
I think QERR_OPEN_FILE_FAILED is simply the wrong error here. We don't
know that the error occurred when trying to open a file.
Right.
errno does not necessarily contain the error value!
There are two ways to fix it (and they're not mutually exclusive):
1. We could review all bdrv_reopen_prepare() methods and make sure they
set errno on failure
2. We set errno=0 before calling the bdrv_reopen_prepare() method and if
there's an error and if errno != 0 we use it, otherwise we set a generic
failed to prepare to reopen image error
Option 1 goes a bit beyond the time I'd like to spent on this series.
Option 2 is quite reasonable.
What do you think?
errno is definitely not reliable here and won't be. You must use -ret if
you want a meaningful error message.
I think Stefan's point was more that Could not open might not be the
right message for a reopen, so we'd have to use error_setg_errno()
directly with a different message here, like Could not prepare reopen
for '%s'.
The _real_ solution, of course, is to make bdrv_prepare_reopen() a void
function and always set errp when something goes wrong.
Kevin
Re: [Qemu-devel] [PATCH 3/9] block: bdrv_reopen_prepare(): use error_setg_file_open()
On Mon, 10 Jun 2013 15:54:10 +0200
Kevin Wolf kw...@redhat.com wrote:
Am 10.06.2013 um 15:21 hat Luiz Capitulino geschrieben:
On Mon, 10 Jun 2013 10:43:47 +0200
Stefan Hajnoczi stefa...@gmail.com wrote:
On Fri, Jun 07, 2013 at 03:52:29PM -0400, Luiz Capitulino wrote:
Signed-off-by: Luiz Capitulino lcapitul...@redhat.com
---
block.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/block.c b/block.c
index 79ad33d..c78f152 100644
--- a/block.c
+++ b/block.c
@@ -1291,8 +1291,7 @@ 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_file_open(errp, errno,
reopen_state-bs-filename);
Looking closer, my suggestion was wrong too.
I think QERR_OPEN_FILE_FAILED is simply the wrong error here. We don't
know that the error occurred when trying to open a file.
Right.
errno does not necessarily contain the error value!
There are two ways to fix it (and they're not mutually exclusive):
1. We could review all bdrv_reopen_prepare() methods and make sure they
set errno on failure
2. We set errno=0 before calling the bdrv_reopen_prepare() method and if
there's an error and if errno != 0 we use it, otherwise we set a generic
failed to prepare to reopen image error
Option 1 goes a bit beyond the time I'd like to spent on this series.
Option 2 is quite reasonable.
What do you think?
errno is definitely not reliable here and won't be. You must use -ret if
you want a meaningful error message.
I think Stefan's point was more that Could not open might not be the
right message for a reopen, so we'd have to use error_setg_errno()
directly with a different message here, like Could not prepare reopen
for '%s'.
Ok, but Stefan also said that -ret is not reliable. And after quickly
checking the code I see he's right, as there are methods that return -1.
I think the safest thing to do is to have a generic error message for
for this now and in the future we should propagate errp or return -errno.
Re: [Qemu-devel] [PATCH 3/9] block: bdrv_reopen_prepare(): use error_setg_file_open()
Am 10.06.2013 um 16:02 hat Luiz Capitulino geschrieben:
On Mon, 10 Jun 2013 15:54:10 +0200
Kevin Wolf kw...@redhat.com wrote:
Am 10.06.2013 um 15:21 hat Luiz Capitulino geschrieben:
On Mon, 10 Jun 2013 10:43:47 +0200
Stefan Hajnoczi stefa...@gmail.com wrote:
On Fri, Jun 07, 2013 at 03:52:29PM -0400, Luiz Capitulino wrote:
Signed-off-by: Luiz Capitulino lcapitul...@redhat.com
---
block.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/block.c b/block.c
index 79ad33d..c78f152 100644
--- a/block.c
+++ b/block.c
@@ -1291,8 +1291,7 @@ 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_file_open(errp, errno,
reopen_state-bs-filename);
Looking closer, my suggestion was wrong too.
I think QERR_OPEN_FILE_FAILED is simply the wrong error here. We don't
know that the error occurred when trying to open a file.
Right.
errno does not necessarily contain the error value!
There are two ways to fix it (and they're not mutually exclusive):
1. We could review all bdrv_reopen_prepare() methods and make sure they
set errno on failure
2. We set errno=0 before calling the bdrv_reopen_prepare() method and if
there's an error and if errno != 0 we use it, otherwise we set a
generic
failed to prepare to reopen image error
Option 1 goes a bit beyond the time I'd like to spent on this series.
Option 2 is quite reasonable.
What do you think?
errno is definitely not reliable here and won't be. You must use -ret if
you want a meaningful error message.
I think Stefan's point was more that Could not open might not be the
right message for a reopen, so we'd have to use error_setg_errno()
directly with a different message here, like Could not prepare reopen
for '%s'.
Ok, but Stefan also said that -ret is not reliable. And after quickly
checking the code I see he's right, as there are methods that return -1.
I think the safest thing to do is to have a generic error message for
for this now and in the future we should propagate errp or return -errno.
Ah, yes. I agree, let's make it error_setg() without errno for now.
Kevin
[Qemu-devel] [PATCH 3/9] block: bdrv_reopen_prepare(): use error_setg_file_open()
Signed-off-by: Luiz Capitulino lcapitul...@redhat.com
---
block.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/block.c b/block.c
index 79ad33d..c78f152 100644
--- a/block.c
+++ b/block.c
@@ -1291,8 +1291,7 @@ 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_file_open(errp, errno, reopen_state-bs-filename);
}
goto error;
}
--
1.8.1.4
