On Thu, Mar 15, 2012 at 11:52:32AM -0300, Luiz Capitulino wrote:
> On Thu, 15 Mar 2012 00:55:10 +0200
> Alon Levy <al...@redhat.com> wrote:
>
> > Signed-off-by: Alon Levy <al...@redhat.com>
> > ---
> > cpus.c | 4 ++--
> > error.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
> > error.h | 4 ++++
> > qerror.c | 36 ++++++++++++++++++++++++++++++++++++
> > qerror.h | 27 +++++++++++++++++++++++++++
> > qga/commands-posix.c | 2 +-
> > 6 files changed, 114 insertions(+), 3 deletions(-)
> >
> > diff --git a/cpus.c b/cpus.c
> > index 17b055f..c87035f 100644
> > --- a/cpus.c
> > +++ b/cpus.c
> > @@ -1178,7 +1178,7 @@ 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_set_file_open_failed(errp, filename, errno);
> > return;
> > }
> >
> > @@ -1208,7 +1208,7 @@ 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_set_file_open_failed(errp, filename, errno);
> > return;
> > }
> >
> > diff --git a/error.c b/error.c
> > index 990050f..b32d7f5 100644
> > --- a/error.c
> > +++ b/error.c
> > @@ -144,3 +144,47 @@ void error_set_qobject(Error **errp, QObject *obj)
> >
> > *errp = err;
> > }
> > +
> > +void error_set_file_open_failed(Error **errp, const char *file_name, int
> > ret)
> > +{
>
> I prefer having:
>
> void qemu_fopen_err(const char *filename, const char *mode, Error **errp);
OK.
>
> It could live in osdep.c I think.
OK.
>
> Also, please split this into two patches:
>
> 1. Add all the errors
> 2. Add qemu_fopen_err()
OK.
>
> And don't change unrelated code. Other commands that will benefit from the
> new function should be converted in a different series.
>
OK.
> CC'ing Anthony in case he has a different suggestion for the fopen()
> wrapper (of course we can an open() version too).
>
> > + const char *fmt = NULL;
> > +
> > + switch (ret) {
> > + case EACCES:
> > + fmt = QERR_OPEN_FILE_EACCES;
> > + break;
> > + case EINTR:
> > + fmt = QERR_OPEN_FILE_EINTR;
> > + break;
> > + case EEXIST:
> > + fmt = QERR_OPEN_FILE_EEXIST;
> > + break;
> > + case EMFILE:
> > + fmt = QERR_OPEN_FILE_EMFILE;
> > + break;
> > + case ENOSPC:
> > + fmt = QERR_OPEN_FILE_ENOSPC;
> > + break;
> > + case EPERM:
> > + fmt = QERR_OPEN_FILE_EPERM;
> > + break;
> > + case EROFS:
> > + fmt = QERR_OPEN_FILE_EROFS;
> > + break;
> > + case ENOTDIR:
> > + fmt = QERR_OPEN_FILE_ENOTDIR;
> > + break;
> > + case EFBIG:
> > + fmt = QERR_OPEN_FILE_EFBIG;
> > + break;
> > + default:
> > + /*
> > + * EINVAL and ENOTSUP will result in the default
> > + *
> > + * ENOENT too, it's used by (for instance) bdrv_create_file for
> > + * a different purpose then open (2) so just give a generic error.
> > + */
> > + fmt = QERR_OPEN_FILE_FAILED;
> > + }
> > + error_set(errp, fmt, file_name);
> > +}
> > diff --git a/error.h b/error.h
> > index 6361f40..f3a80f3 100644
> > --- a/error.h
> > +++ b/error.h
> > @@ -67,4 +67,8 @@ void error_free(Error *err);
> > */
> > bool error_is_type(Error *err, const char *fmt);
> >
> > +/**
> > + * Helper to set error for a open (2) style return code.
> > + */
> > +void error_set_file_open_failed(Error **errp, const char *file_name, int
> > ret);
> > #endif
> > diff --git a/qerror.c b/qerror.c
> > index f55d435..23c260b 100644
> > --- a/qerror.c
> > +++ b/qerror.c
> > @@ -213,6 +213,42 @@ static const QErrorStringTable qerror_table[] = {
> > .desc = "Could not open '%(filename)'",
> > },
> > {
> > + .error_fmt = QERR_OPEN_FILE_EINTR,
> > + .desc = "Interrupted open of '%(filename)'",
> > + },
>
> I see that you're adding _OPEN_FILE_ flavors to be able to pass the filename
> in the error. But this just workarounds a limitation of qerror: we should be
> able to set the error message at run-time.
>
> I think the best thing to do is to have QERR_EINTR instead, with a generic
> message like "Operation has been interrupted" and we can improve QError to
> extend it to contain the file name.
>
Sounds like we would not have the filename then, which would be a shame.
But I don't mind doing that.
> This is valid for all errors below.
>
> > + {
> > + .error_fmt = QERR_OPEN_FILE_EACCES,
> > + .desc = "Cannot access '%(filename)'",
> > + },
>
> We already have PermissionDenied.
>
Not the same use case - QERR_PERMISSION_DENIED is used for internal
errors, not for an open / file related system permission error.
> > + {
> > + .error_fmt = QERR_OPEN_FILE_EEXIST,
> > + .desc = "File already exists '%(filename)'",
> > + },
>
> I wouldn't mind not having this one because most of the time qemu doesn't
> care if the file already exists.
I was really just going over everything open (2) manpage and copying
what looked like it made sense. I can drop it.
>
> > + {
> > + .error_fmt = QERR_OPEN_FILE_EMFILE,
> > + .desc = "Max open files when opening '%(filename)'",
> > + },
>
> This is an exception for what I said about _OPEN_FILE_ flavors above, this
> is fine because it's really a file error.
They are all open (2) errors, see previous comment :)
>
> > + {
> > + .error_fmt = QERR_OPEN_FILE_ENOSPC,
> > + .desc = "No space left opening '%(filename)'",
> > + },
> > + {
> > + .error_fmt = QERR_OPEN_FILE_EPERM,
> > + .desc = "Permission denied (EPERM) for '%(filename)'",
> > + },
>
> I wouldn't mind reporting EACCESS and EPERM the same.
But why do that? they are different at the system level, no reason to
merge them. Except for EPERM being a bit cryptic (to me) it doesn't seem
to be the same as EACCESS.
>
> > + {
> > + .error_fmt = QERR_OPEN_FILE_EROFS,
> > + .desc = "Read only filesystem opening '%(filename)'",
> > + },
>
> Let's have a QERR_READ_ONLY.
OK.
>
> > + {
> > + .error_fmt = QERR_OPEN_FILE_ENOTDIR,
> > + .desc = "Directory related error opening '%(filename)'",
> > + },
> > + {
> > + .error_fmt = QERR_OPEN_FILE_EFBIG,
> > + .desc = "File too big opening '%(filename)'",
> > + },
> > + {
> > .error_fmt = QERR_PERMISSION_DENIED,
> > .desc = "Insufficient permission to perform this operation",
> > },
> > diff --git a/qerror.h b/qerror.h
> > index e26c635..6ab9b8d 100644
> > --- a/qerror.h
> > +++ b/qerror.h
> > @@ -181,6 +181,33 @@ QError *qobject_to_qerror(const QObject *obj);
> > #define QERR_OPEN_FILE_FAILED \
> > "{ 'class': 'OpenFileFailed', 'data': { 'filename': %s } }"
> >
> > +#define QERR_OPEN_FILE_EINTR \
> > + "{ 'class': 'OpenFileEINTR', 'data': { 'filename': %s } }"
> > +
> > +#define QERR_OPEN_FILE_EACCES \
> > + "{ 'class': 'OpenFileEACCES', 'data': { 'filename': %s } }"
> > +
> > +#define QERR_OPEN_FILE_EEXIST \
> > + "{ 'class': 'OpenFileEEXIST', 'data': { 'filename': %s } }"
> > +
> > +#define QERR_OPEN_FILE_EMFILE \
> > + "{ 'class': 'OpenFileEMFILE', 'data': { 'filename': %s } }"
> > +
> > +#define QERR_OPEN_FILE_ENOSPC \
> > + "{ 'class': 'OpenFileENOSPC', 'data': { 'filename': %s } }"
> > +
> > +#define QERR_OPEN_FILE_EPERM \
> > + "{ 'class': 'OpenFileEPERM', 'data': { 'filename': %s } }"
> > +
> > +#define QERR_OPEN_FILE_EROFS \
> > + "{ 'class': 'OpenFileEROFS', 'data': { 'filename': %s } }"
> > +
> > +#define QERR_OPEN_FILE_ENOTDIR \
> > + "{ 'class': 'OpenFileENOTDIR', 'data': { 'filename': %s } }"
> > +
> > +#define QERR_OPEN_FILE_EFBIG \
> > + "{ 'class': 'OpenFileEFBIG', 'data': { 'filename': %s } }"
> > +
> > #define QERR_PERMISSION_DENIED \
> > "{ 'class': 'PermissionDenied', 'data': {} }"
> >
> > diff --git a/qga/commands-posix.c b/qga/commands-posix.c
> > index 7b2be2f..4e5ef7f 100644
> > --- a/qga/commands-posix.c
> > +++ b/qga/commands-posix.c
> > @@ -134,7 +134,7 @@ int64_t qmp_guest_file_open(const char *path, bool
> > has_mode, const char *mode, E
> > slog("guest-file-open called, filepath: %s, mode: %s", path, mode);
> > fh = fopen(path, mode);
> > if (!fh) {
> > - error_set(err, QERR_OPEN_FILE_FAILED, path);
> > + error_set_file_open_failed(err, path, errno);
> > return -1;
> > }
> >
>
