| Message ID | 1410549984-16110-2-git-send-email-armbru@redhat.com |
|---|---|
| State | New |
| Headers | show |
On 12.09.2014 21:26, Markus Armbruster wrote: > blockdev_init() mixes up BlockDriverState and DriveInfo initialization > Finish the BlockDriverState job before starting to mess with > DriveInfo. Easier on the eyes. > > Signed-off-by: Markus Armbruster <armbru@redhat.com> > --- > blockdev.c | 43 +++++++++++++++++++++++-------------------- > 1 file changed, 23 insertions(+), 20 deletions(-) > > diff --git a/blockdev.c b/blockdev.c > index b361fbb..5ec4635 100644 > --- a/blockdev.c > +++ b/blockdev.c > @@ -301,6 +301,7 @@ static DriveInfo *blockdev_init(const char *file, QDict *bs_opts, > int ro = 0; > int bdrv_flags = 0; > int on_read_error, on_write_error; > + BlockDriverState *bs; > DriveInfo *dinfo; > ThrottleConfig cfg; > int snapshot = 0; > @@ -456,26 +457,27 @@ static DriveInfo *blockdev_init(const char *file, QDict *bs_opts, > } > > /* init */ > + bs = bdrv_new(qemu_opts_id(opts), errp); > + if (!bs) { > + goto early_err; > + } > + bs->open_flags = snapshot ? BDRV_O_SNAPSHOT : 0; > + bs->read_only = ro; > + bs->detect_zeroes = detect_zeroes; > + > + bdrv_set_on_error(bs, on_read_error, on_write_error); > + > + /* disk I/O throttling */ > + if (throttle_enabled(&cfg)) { > + bdrv_io_limits_enable(bs); > + bdrv_set_io_limits(bs, &cfg); > + } > + > dinfo = g_malloc0(sizeof(*dinfo)); Could've changed this to g_new0 in the process, but you're the expert for that, so I'll leave it up to you. ;-) > dinfo->id = g_strdup(qemu_opts_id(opts)); > - dinfo->bdrv = bdrv_new(dinfo->id, &error); > - if (error) { > - error_propagate(errp, error); > - goto bdrv_new_err; > - } > - dinfo->bdrv->open_flags = snapshot ? BDRV_O_SNAPSHOT : 0; > - dinfo->bdrv->read_only = ro; > - dinfo->bdrv->detect_zeroes = detect_zeroes; > + dinfo->bdrv = bs; > QTAILQ_INSERT_TAIL(&drives, dinfo, next); > > - bdrv_set_on_error(dinfo->bdrv, on_read_error, on_write_error); > - > - /* disk I/O throttling */ > - if (throttle_enabled(&cfg)) { > - bdrv_io_limits_enable(dinfo->bdrv); > - bdrv_set_io_limits(dinfo->bdrv, &cfg); > - } > - > if (!file || !*file) { > if (has_driver_specific_opts) { > file = NULL; > @@ -502,7 +504,8 @@ static DriveInfo *blockdev_init(const char *file, QDict *bs_opts, > bdrv_flags |= ro ? 0 : BDRV_O_RDWR; > > QINCREF(bs_opts); > - ret = bdrv_open(&dinfo->bdrv, file, NULL, bs_opts, bdrv_flags, drv, &error); > + ret = bdrv_open(&bs, file, NULL, bs_opts, bdrv_flags, drv, &error); > + assert(bs == dinfo->bdrv); Well, this is guaranteed by bdrv_open(), but of course better having too many assertions than too few. With or without g_new0: Reviewed-by: Max Reitz <mreitz@redhat.com>
Max Reitz <mreitz@redhat.com> writes: > On 12.09.2014 21:26, Markus Armbruster wrote: >> blockdev_init() mixes up BlockDriverState and DriveInfo initialization >> Finish the BlockDriverState job before starting to mess with >> DriveInfo. Easier on the eyes. >> >> Signed-off-by: Markus Armbruster <armbru@redhat.com> >> --- >> blockdev.c | 43 +++++++++++++++++++++++-------------------- >> 1 file changed, 23 insertions(+), 20 deletions(-) >> >> diff --git a/blockdev.c b/blockdev.c >> index b361fbb..5ec4635 100644 >> --- a/blockdev.c >> +++ b/blockdev.c >> @@ -301,6 +301,7 @@ static DriveInfo *blockdev_init(const char *file, QDict *bs_opts, >> int ro = 0; >> int bdrv_flags = 0; >> int on_read_error, on_write_error; >> + BlockDriverState *bs; >> DriveInfo *dinfo; >> ThrottleConfig cfg; >> int snapshot = 0; >> @@ -456,26 +457,27 @@ static DriveInfo *blockdev_init(const char *file, QDict *bs_opts, >> } >> /* init */ >> + bs = bdrv_new(qemu_opts_id(opts), errp); >> + if (!bs) { >> + goto early_err; >> + } >> + bs->open_flags = snapshot ? BDRV_O_SNAPSHOT : 0; >> + bs->read_only = ro; >> + bs->detect_zeroes = detect_zeroes; >> + >> + bdrv_set_on_error(bs, on_read_error, on_write_error); >> + >> + /* disk I/O throttling */ >> + if (throttle_enabled(&cfg)) { >> + bdrv_io_limits_enable(bs); >> + bdrv_set_io_limits(bs, &cfg); >> + } >> + >> dinfo = g_malloc0(sizeof(*dinfo)); > > Could've changed this to g_new0 in the process, but you're the expert > for that, so I'll leave it up to you. ;-) When I made block use g_new() & friends, I only converted patterns like p = g_malloc(sizeof(T)), not patterns like p = g_malloc(sizeof(*p)). In the former case, p = g_new(T) is a clear improvement, because now the compiler checks T matches typeof(*p). In the latter case, we trade some visible obviousness for type safety. Matter of taste. If we agree to prefer type safety in block land, I'll gladly do the conversion work. >> dinfo->id = g_strdup(qemu_opts_id(opts)); >> - dinfo->bdrv = bdrv_new(dinfo->id, &error); >> - if (error) { >> - error_propagate(errp, error); >> - goto bdrv_new_err; >> - } >> - dinfo->bdrv->open_flags = snapshot ? BDRV_O_SNAPSHOT : 0; >> - dinfo->bdrv->read_only = ro; >> - dinfo->bdrv->detect_zeroes = detect_zeroes; >> + dinfo->bdrv = bs; >> QTAILQ_INSERT_TAIL(&drives, dinfo, next); >> - bdrv_set_on_error(dinfo->bdrv, on_read_error, >> on_write_error); >> - >> - /* disk I/O throttling */ >> - if (throttle_enabled(&cfg)) { >> - bdrv_io_limits_enable(dinfo->bdrv); >> - bdrv_set_io_limits(dinfo->bdrv, &cfg); >> - } >> - >> if (!file || !*file) { >> if (has_driver_specific_opts) { >> file = NULL; >> @@ -502,7 +504,8 @@ static DriveInfo *blockdev_init(const char *file, QDict *bs_opts, >> bdrv_flags |= ro ? 0 : BDRV_O_RDWR; >> QINCREF(bs_opts); >> - ret = bdrv_open(&dinfo->bdrv, file, NULL, bs_opts, bdrv_flags, drv, &error); >> + ret = bdrv_open(&bs, file, NULL, bs_opts, bdrv_flags, drv, &error); >> + assert(bs == dinfo->bdrv); > > Well, this is guaranteed by bdrv_open(), but of course better having > too many assertions than too few. Indeed. bdrv_open() is in another file, and its function comment doesn't quite spell out this part of its contract. Assertions do double-duty: they check assumptions are valid, and they remind the reader of assumptions. The second part can be useful even when the first part is trivial. > With or without g_new0: > > Reviewed-by: Max Reitz <mreitz@redhat.com> Thanks!
The Friday 12 Sep 2014 à 21:26:21 (+0200), Markus Armbruster wrote : > blockdev_init() mixes up BlockDriverState and DriveInfo initialization > Finish the BlockDriverState job before starting to mess with > DriveInfo. Easier on the eyes. > > Signed-off-by: Markus Armbruster <armbru@redhat.com> > --- > blockdev.c | 43 +++++++++++++++++++++++-------------------- > 1 file changed, 23 insertions(+), 20 deletions(-) > > diff --git a/blockdev.c b/blockdev.c > index b361fbb..5ec4635 100644 > --- a/blockdev.c > +++ b/blockdev.c > @@ -301,6 +301,7 @@ static DriveInfo *blockdev_init(const char *file, QDict *bs_opts, > int ro = 0; > int bdrv_flags = 0; > int on_read_error, on_write_error; > + BlockDriverState *bs; > DriveInfo *dinfo; > ThrottleConfig cfg; > int snapshot = 0; > @@ -456,26 +457,27 @@ static DriveInfo *blockdev_init(const char *file, QDict *bs_opts, > } > > /* init */ > + bs = bdrv_new(qemu_opts_id(opts), errp); > + if (!bs) { > + goto early_err; > + } > + bs->open_flags = snapshot ? BDRV_O_SNAPSHOT : 0; > + bs->read_only = ro; > + bs->detect_zeroes = detect_zeroes; > + > + bdrv_set_on_error(bs, on_read_error, on_write_error); > + > + /* disk I/O throttling */ > + if (throttle_enabled(&cfg)) { > + bdrv_io_limits_enable(bs); > + bdrv_set_io_limits(bs, &cfg); > + } > + > dinfo = g_malloc0(sizeof(*dinfo)); > dinfo->id = g_strdup(qemu_opts_id(opts)); > - dinfo->bdrv = bdrv_new(dinfo->id, &error); > - if (error) { > - error_propagate(errp, error); > - goto bdrv_new_err; > - } > - dinfo->bdrv->open_flags = snapshot ? BDRV_O_SNAPSHOT : 0; > - dinfo->bdrv->read_only = ro; > - dinfo->bdrv->detect_zeroes = detect_zeroes; > + dinfo->bdrv = bs; > QTAILQ_INSERT_TAIL(&drives, dinfo, next); > > - bdrv_set_on_error(dinfo->bdrv, on_read_error, on_write_error); > - > - /* disk I/O throttling */ > - if (throttle_enabled(&cfg)) { > - bdrv_io_limits_enable(dinfo->bdrv); > - bdrv_set_io_limits(dinfo->bdrv, &cfg); > - } > - > if (!file || !*file) { > if (has_driver_specific_opts) { > file = NULL; > @@ -502,7 +504,8 @@ static DriveInfo *blockdev_init(const char *file, QDict *bs_opts, > bdrv_flags |= ro ? 0 : BDRV_O_RDWR; > > QINCREF(bs_opts); > - ret = bdrv_open(&dinfo->bdrv, file, NULL, bs_opts, bdrv_flags, drv, &error); > + ret = bdrv_open(&bs, file, NULL, bs_opts, bdrv_flags, drv, &error); > + assert(bs == dinfo->bdrv); > > if (ret < 0) { > error_setg(errp, "could not open disk image %s: %s", > @@ -511,8 +514,9 @@ static DriveInfo *blockdev_init(const char *file, QDict *bs_opts, > goto err; > } > > - if (bdrv_key_required(dinfo->bdrv)) > + if (bdrv_key_required(bs)) { > autostart = 0; > + } > > QDECREF(bs_opts); > qemu_opts_del(opts); > @@ -520,9 +524,8 @@ static DriveInfo *blockdev_init(const char *file, QDict *bs_opts, > return dinfo; > > err: > - bdrv_unref(dinfo->bdrv); > + bdrv_unref(bs); I would have moved this. > QTAILQ_REMOVE(&drives, dinfo, next); > -bdrv_new_err: > g_free(dinfo->id); > g_free(dinfo); To Here. No functional difference but it would reflect it's goto chain role: being in the reverse order of the allocations. > early_err: > -- > 1.9.3 Reviewed-by: Benoît Canet <benoit.canet@nodalink.com> >
Benoît Canet <benoit.canet@irqsave.net> writes: > The Friday 12 Sep 2014 à 21:26:21 (+0200), Markus Armbruster wrote : >> blockdev_init() mixes up BlockDriverState and DriveInfo initialization >> Finish the BlockDriverState job before starting to mess with >> DriveInfo. Easier on the eyes. >> >> Signed-off-by: Markus Armbruster <armbru@redhat.com> >> --- >> blockdev.c | 43 +++++++++++++++++++++++-------------------- >> 1 file changed, 23 insertions(+), 20 deletions(-) >> >> diff --git a/blockdev.c b/blockdev.c >> index b361fbb..5ec4635 100644 >> --- a/blockdev.c >> +++ b/blockdev.c >> @@ -301,6 +301,7 @@ static DriveInfo *blockdev_init(const char *file, QDict *bs_opts, >> int ro = 0; >> int bdrv_flags = 0; >> int on_read_error, on_write_error; >> + BlockDriverState *bs; >> DriveInfo *dinfo; >> ThrottleConfig cfg; >> int snapshot = 0; >> @@ -456,26 +457,27 @@ static DriveInfo *blockdev_init(const char *file, QDict *bs_opts, >> } >> >> /* init */ >> + bs = bdrv_new(qemu_opts_id(opts), errp); >> + if (!bs) { >> + goto early_err; >> + } >> + bs->open_flags = snapshot ? BDRV_O_SNAPSHOT : 0; >> + bs->read_only = ro; >> + bs->detect_zeroes = detect_zeroes; >> + >> + bdrv_set_on_error(bs, on_read_error, on_write_error); >> + >> + /* disk I/O throttling */ >> + if (throttle_enabled(&cfg)) { >> + bdrv_io_limits_enable(bs); >> + bdrv_set_io_limits(bs, &cfg); >> + } >> + >> dinfo = g_malloc0(sizeof(*dinfo)); >> dinfo->id = g_strdup(qemu_opts_id(opts)); >> - dinfo->bdrv = bdrv_new(dinfo->id, &error); >> - if (error) { >> - error_propagate(errp, error); >> - goto bdrv_new_err; >> - } >> - dinfo->bdrv->open_flags = snapshot ? BDRV_O_SNAPSHOT : 0; >> - dinfo->bdrv->read_only = ro; >> - dinfo->bdrv->detect_zeroes = detect_zeroes; >> + dinfo->bdrv = bs; >> QTAILQ_INSERT_TAIL(&drives, dinfo, next); >> >> - bdrv_set_on_error(dinfo->bdrv, on_read_error, on_write_error); >> - >> - /* disk I/O throttling */ >> - if (throttle_enabled(&cfg)) { >> - bdrv_io_limits_enable(dinfo->bdrv); >> - bdrv_set_io_limits(dinfo->bdrv, &cfg); >> - } >> - >> if (!file || !*file) { >> if (has_driver_specific_opts) { >> file = NULL; >> @@ -502,7 +504,8 @@ static DriveInfo *blockdev_init(const char *file, QDict *bs_opts, >> bdrv_flags |= ro ? 0 : BDRV_O_RDWR; >> >> QINCREF(bs_opts); >> - ret = bdrv_open(&dinfo->bdrv, file, NULL, bs_opts, bdrv_flags, drv, &error); >> + ret = bdrv_open(&bs, file, NULL, bs_opts, bdrv_flags, drv, &error); >> + assert(bs == dinfo->bdrv); >> >> if (ret < 0) { >> error_setg(errp, "could not open disk image %s: %s", >> @@ -511,8 +514,9 @@ static DriveInfo *blockdev_init(const char *file, QDict *bs_opts, >> goto err; >> } >> >> - if (bdrv_key_required(dinfo->bdrv)) >> + if (bdrv_key_required(bs)) { >> autostart = 0; >> + } >> >> QDECREF(bs_opts); >> qemu_opts_del(opts); >> @@ -520,9 +524,8 @@ static DriveInfo *blockdev_init(const char *file, QDict *bs_opts, >> return dinfo; >> >> err: >> - bdrv_unref(dinfo->bdrv); > >> + bdrv_unref(bs); > I would have moved this. > >> QTAILQ_REMOVE(&drives, dinfo, next); >> -bdrv_new_err: >> g_free(dinfo->id); >> g_free(dinfo); > > To Here. > > No functional difference but it would reflect it's goto chain role: > being in the reverse order of the allocations. You're right. In the BlockBackend series, this becomes just err: blk_unref(blk); early_err: so the disorder is just temporary. I'll change it anyway if I have to respin for some other reason. >> early_err: >> -- >> 1.9.3 > > Reviewed-by: Benoît Canet <benoit.canet@nodalink.com> Thanks!
diff --git a/blockdev.c b/blockdev.c index b361fbb..5ec4635 100644 --- a/blockdev.c +++ b/blockdev.c @@ -301,6 +301,7 @@ static DriveInfo *blockdev_init(const char *file, QDict *bs_opts, int ro = 0; int bdrv_flags = 0; int on_read_error, on_write_error; + BlockDriverState *bs; DriveInfo *dinfo; ThrottleConfig cfg; int snapshot = 0; @@ -456,26 +457,27 @@ static DriveInfo *blockdev_init(const char *file, QDict *bs_opts, } /* init */ + bs = bdrv_new(qemu_opts_id(opts), errp); + if (!bs) { + goto early_err; + } + bs->open_flags = snapshot ? BDRV_O_SNAPSHOT : 0; + bs->read_only = ro; + bs->detect_zeroes = detect_zeroes; + + bdrv_set_on_error(bs, on_read_error, on_write_error); + + /* disk I/O throttling */ + if (throttle_enabled(&cfg)) { + bdrv_io_limits_enable(bs); + bdrv_set_io_limits(bs, &cfg); + } + dinfo = g_malloc0(sizeof(*dinfo)); dinfo->id = g_strdup(qemu_opts_id(opts)); - dinfo->bdrv = bdrv_new(dinfo->id, &error); - if (error) { - error_propagate(errp, error); - goto bdrv_new_err; - } - dinfo->bdrv->open_flags = snapshot ? BDRV_O_SNAPSHOT : 0; - dinfo->bdrv->read_only = ro; - dinfo->bdrv->detect_zeroes = detect_zeroes; + dinfo->bdrv = bs; QTAILQ_INSERT_TAIL(&drives, dinfo, next); - bdrv_set_on_error(dinfo->bdrv, on_read_error, on_write_error); - - /* disk I/O throttling */ - if (throttle_enabled(&cfg)) { - bdrv_io_limits_enable(dinfo->bdrv); - bdrv_set_io_limits(dinfo->bdrv, &cfg); - } - if (!file || !*file) { if (has_driver_specific_opts) { file = NULL; @@ -502,7 +504,8 @@ static DriveInfo *blockdev_init(const char *file, QDict *bs_opts, bdrv_flags |= ro ? 0 : BDRV_O_RDWR; QINCREF(bs_opts); - ret = bdrv_open(&dinfo->bdrv, file, NULL, bs_opts, bdrv_flags, drv, &error); + ret = bdrv_open(&bs, file, NULL, bs_opts, bdrv_flags, drv, &error); + assert(bs == dinfo->bdrv); if (ret < 0) { error_setg(errp, "could not open disk image %s: %s", @@ -511,8 +514,9 @@ static DriveInfo *blockdev_init(const char *file, QDict *bs_opts, goto err; } - if (bdrv_key_required(dinfo->bdrv)) + if (bdrv_key_required(bs)) { autostart = 0; + } QDECREF(bs_opts); qemu_opts_del(opts); @@ -520,9 +524,8 @@ static DriveInfo *blockdev_init(const char *file, QDict *bs_opts, return dinfo; err: - bdrv_unref(dinfo->bdrv); + bdrv_unref(bs); QTAILQ_REMOVE(&drives, dinfo, next); -bdrv_new_err: g_free(dinfo->id); g_free(dinfo); early_err:
blockdev_init() mixes up BlockDriverState and DriveInfo initialization Finish the BlockDriverState job before starting to mess with DriveInfo. Easier on the eyes. Signed-off-by: Markus Armbruster <armbru@redhat.com> --- blockdev.c | 43 +++++++++++++++++++++++-------------------- 1 file changed, 23 insertions(+), 20 deletions(-)