| Message ID | 20170725194337.GA20979@redhat.com (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Delegated to: | Mike Snitzer |
| Headers | show |
On Tue, Jul 25, 2017 at 12:43 PM, Vivek Goyal <vgoyal@redhat.com> wrote: > Right now, dm_dax_flush() is not being called and I think it is not being > called becuase DAXDEV_WRITE_CACHE is not set on dm dax device. > > If underlying dax device supports write cache, set DAXDEV_WRITE_CACHE on > dm dax device. This will get dm_dax_flush() being called. > > Signed-off-by: Vivek Goyal <vgoyal@redhat.com> > --- > drivers/dax/super.c | 5 +++++ > drivers/md/dm-table.c | 33 +++++++++++++++++++++++++++++++++ > include/linux/dax.h | 1 + > 3 files changed, 39 insertions(+) > > diff --git a/drivers/dax/super.c b/drivers/dax/super.c > index ce9e563e6e1d..5c5e7b9f6831 100644 > --- a/drivers/dax/super.c > +++ b/drivers/dax/super.c > @@ -278,6 +278,11 @@ void dax_write_cache(struct dax_device *dax_dev, bool wc) > } > EXPORT_SYMBOL_GPL(dax_write_cache); > > +bool dax_write_cache_enabled(struct dax_device *dax_dev) > +{ > + return test_bit(DAXDEV_WRITE_CACHE, &dax_dev->flags); > +} We need : EXPORT_SYMBOL_GPL(dax_write_cache_enabled) ...but other than that, looks good to me. Acked-by: Dan Williams <dan.j.williams@intel.com> -- dm-devel mailing list dm-devel@redhat.com https://www.redhat.com/mailman/listinfo/dm-devel
On Tue, Jul 25 2017 at 3:43pm -0400, Vivek Goyal <vgoyal@redhat.com> wrote: > Right now, dm_dax_flush() is not being called and I think it is not being > called becuase DAXDEV_WRITE_CACHE is not set on dm dax device. > > If underlying dax device supports write cache, set DAXDEV_WRITE_CACHE on > dm dax device. This will get dm_dax_flush() being called. > > Signed-off-by: Vivek Goyal <vgoyal@redhat.com> In general this looks mostly OK.. but it seems a bit weird to on the one hand: test if DAXDEV_WRITE_CACHE is set on underlying device. And on the other: say it is a write cache because it is "flush_capable". Kind of blurring things a bit. Why not s/device_dax_flush_capable/device_dax_write_cache_enabled/ ? Mike -- dm-devel mailing list dm-devel@redhat.com https://www.redhat.com/mailman/listinfo/dm-devel
On Tue, Jul 25, 2017 at 01:43:27PM -0700, Dan Williams wrote: > On Tue, Jul 25, 2017 at 12:43 PM, Vivek Goyal <vgoyal@redhat.com> wrote: > > Right now, dm_dax_flush() is not being called and I think it is not being > > called becuase DAXDEV_WRITE_CACHE is not set on dm dax device. > > > > If underlying dax device supports write cache, set DAXDEV_WRITE_CACHE on > > dm dax device. This will get dm_dax_flush() being called. > > > > Signed-off-by: Vivek Goyal <vgoyal@redhat.com> > > --- > > drivers/dax/super.c | 5 +++++ > > drivers/md/dm-table.c | 33 +++++++++++++++++++++++++++++++++ > > include/linux/dax.h | 1 + > > 3 files changed, 39 insertions(+) > > > > diff --git a/drivers/dax/super.c b/drivers/dax/super.c > > index ce9e563e6e1d..5c5e7b9f6831 100644 > > --- a/drivers/dax/super.c > > +++ b/drivers/dax/super.c > > @@ -278,6 +278,11 @@ void dax_write_cache(struct dax_device *dax_dev, bool wc) > > } > > EXPORT_SYMBOL_GPL(dax_write_cache); > > > > +bool dax_write_cache_enabled(struct dax_device *dax_dev) > > +{ > > + return test_bit(DAXDEV_WRITE_CACHE, &dax_dev->flags); > > +} > > We need : > > EXPORT_SYMBOL_GPL(dax_write_cache_enabled) > > ...but other than that, looks good to me. Aha, missed that. Will fix in next version. Vivek > > Acked-by: Dan Williams <dan.j.williams@intel.com> -- dm-devel mailing list dm-devel@redhat.com https://www.redhat.com/mailman/listinfo/dm-devel
On Tue, Jul 25, 2017 at 04:46:09PM -0400, Mike Snitzer wrote: > On Tue, Jul 25 2017 at 3:43pm -0400, > Vivek Goyal <vgoyal@redhat.com> wrote: > > > Right now, dm_dax_flush() is not being called and I think it is not being > > called becuase DAXDEV_WRITE_CACHE is not set on dm dax device. > > > > If underlying dax device supports write cache, set DAXDEV_WRITE_CACHE on > > dm dax device. This will get dm_dax_flush() being called. > > > > Signed-off-by: Vivek Goyal <vgoyal@redhat.com> > > In general this looks mostly OK.. but it seems a bit weird to on the one > hand: test if DAXDEV_WRITE_CACHE is set on underlying device. And on > the other: say it is a write cache because it is "flush_capable". Kind > of blurring things a bit. > > Why not s/device_dax_flush_capable/device_dax_write_cache_enabled/ ? Sounds good. I will rename it in next version. Vivek -- dm-devel mailing list dm-devel@redhat.com https://www.redhat.com/mailman/listinfo/dm-devel
diff --git a/drivers/dax/super.c b/drivers/dax/super.c index ce9e563e6e1d..5c5e7b9f6831 100644 --- a/drivers/dax/super.c +++ b/drivers/dax/super.c @@ -278,6 +278,11 @@ void dax_write_cache(struct dax_device *dax_dev, bool wc) } EXPORT_SYMBOL_GPL(dax_write_cache); +bool dax_write_cache_enabled(struct dax_device *dax_dev) +{ + return test_bit(DAXDEV_WRITE_CACHE, &dax_dev->flags); +} + bool dax_alive(struct dax_device *dax_dev) { lockdep_assert_held(&dax_srcu); diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index a39bcd9b982a..3be0ab2a71c8 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -20,6 +20,7 @@ #include <linux/atomic.h> #include <linux/blk-mq.h> #include <linux/mount.h> +#include <linux/dax.h> #define DM_MSG_PREFIX "table" @@ -1630,6 +1631,35 @@ static bool dm_table_supports_flush(struct dm_table *t, unsigned long flush) return false; } +static int device_dax_flush_capable(struct dm_target *ti, struct dm_dev *dev, + sector_t start, sector_t len, void *data) +{ + struct dax_device *dax_dev = dev->dax_dev; + + if (!dax_dev) + return false; + + if (dax_write_cache_enabled(dax_dev)) + return true; + return false; +} + +static int dm_table_supports_dax_flush(struct dm_table *t) +{ + struct dm_target *ti; + unsigned i; + + for (i = 0; i < dm_table_get_num_targets(t); i++) { + ti = dm_table_get_target(t, i); + + if (ti->type->iterate_devices && + ti->type->iterate_devices(ti, device_dax_flush_capable, NULL)) + return true; + } + + return false; +} + static int device_is_nonrot(struct dm_target *ti, struct dm_dev *dev, sector_t start, sector_t len, void *data) { @@ -1785,6 +1815,9 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, } blk_queue_write_cache(q, wc, fua); + if (dm_table_supports_dax_flush(t)) + dax_write_cache(t->md->dax_dev, true); + /* Ensure that all underlying devices are non-rotational. */ if (dm_table_all_devices_attribute(t, device_is_nonrot)) queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q); diff --git a/include/linux/dax.h b/include/linux/dax.h index 794811875732..df97b7af7e2c 100644 --- a/include/linux/dax.h +++ b/include/linux/dax.h @@ -87,6 +87,7 @@ size_t dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr, void dax_flush(struct dax_device *dax_dev, pgoff_t pgoff, void *addr, size_t size); void dax_write_cache(struct dax_device *dax_dev, bool wc); +bool dax_write_cache_enabled(struct dax_device *dax_dev); /* * We use lowest available bit in exceptional entry for locking, one bit for
Right now, dm_dax_flush() is not being called and I think it is not being called becuase DAXDEV_WRITE_CACHE is not set on dm dax device. If underlying dax device supports write cache, set DAXDEV_WRITE_CACHE on dm dax device. This will get dm_dax_flush() being called. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> --- drivers/dax/super.c | 5 +++++ drivers/md/dm-table.c | 33 +++++++++++++++++++++++++++++++++ include/linux/dax.h | 1 + 3 files changed, 39 insertions(+)