similar to: [PATCH] virtio-blk: allow toggling host cache between writeback and writethrough

Previously after device_add_disk returns, the KOBJ_ADD uevent is already emitted. Adding attributes after that is a poor usage of kobject, and in practice may result in race conditions with userspace, for example udev checks availability of certain attributes and initializes /dev entries conditionally. device_add_disk can handle adding attribute group better, so use it. Meanwhile, handle error

Use sysfs_match_string() helper instead of open coded variant. Cc: "Michael S. Tsirkin" <mst at redhat.com> Cc: Jason Wang <jasowang at redhat.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko at linux.intel.com> --- drivers/block/virtio_blk.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/drivers/block/virtio_blk.c

Use sysfs_match_string() helper instead of open coded variant. Cc: "Michael S. Tsirkin" <mst at redhat.com> Cc: Jason Wang <jasowang at redhat.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko at linux.intel.com> --- drivers/block/virtio_blk.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/drivers/block/virtio_blk.c

On Fri, 2017-06-09 at 15:07 +0300, Andy Shevchenko wrote: > Use sysfs_match_string() helper instead of open coded variant. Did I miss maintainer? > > Cc: "Michael S. Tsirkin" <mst at redhat.com> > Cc: Jason Wang <jasowang at redhat.com> > Signed-off-by: Andy Shevchenko <andriy.shevchenko at linux.intel.com> > --- > ?drivers/block/virtio_blk.c | 7

On Mon, Jul 03, 2017 at 03:05:30PM +0300, Andy Shevchenko wrote: > On Fri, 2017-06-09 at 15:07 +0300, Andy Shevchenko wrote: > > Use sysfs_match_string() helper instead of open coded variant. > > Did I miss maintainer? > > > > > Cc: "Michael S. Tsirkin" <mst at redhat.com> > > Cc: Jason Wang <jasowang at redhat.com> > >

On Mon, Jul 03, 2017 at 03:05:30PM +0300, Andy Shevchenko wrote: > On Fri, 2017-06-09 at 15:07 +0300, Andy Shevchenko wrote: > > Use sysfs_match_string() helper instead of open coded variant. > > Did I miss maintainer? > > > > > Cc: "Michael S. Tsirkin" <mst at redhat.com> > > Cc: Jason Wang <jasowang at redhat.com> > >

Latest virtio spec says the feature bit name is VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_WCE is the legacy name. virtio blk header says exactly the reverse - fix that and update driver code to match. Cc: Paolo Bonzini <pbonzini at redhat.com> Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- Changs from v1: comments updated include/uapi/linux/virtio_blk.h | 6 +++---

Latest virtio spec says the feature bit name is VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_WCE is the legacy name. virtio blk header says exactly the reverse - fix that and update driver code to match. Cc: Paolo Bonzini <pbonzini at redhat.com> Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- Changs from v1: comments updated include/uapi/linux/virtio_blk.h | 6 +++---

Latest virtio spec says the feature bit name is VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_WCE is the legacy name. virtio blk header says exactly the reverse - fix that and update driver code to match. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- I'm inclined to merge it for the current kernel - safe and avoids confusion. include/uapi/linux/virtio_blk.h | 6 +++---

Latest virtio spec says the feature bit name is VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_WCE is the legacy name. virtio blk header says exactly the reverse - fix that and update driver code to match. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- I'm inclined to merge it for the current kernel - safe and avoids confusion. include/uapi/linux/virtio_blk.h | 6 +++---

VIRTIO_BLK_F_CONFIG_WCE is important in order to achieve good performance (up to 2x, though more realistically +30-40%) in latency-bound workloads. However, it was removed by mistake together with VIRTIO_BLK_F_FLUSH. It will be restored in the next revision of the virtio 1.0 standard, so do the same in Linux. Signed-off-by: Paolo Bonzini <pbonzini at redhat.com> ---

VIRTIO_BLK_F_CONFIG_WCE is important in order to achieve good performance (up to 2x, though more realistically +30-40%) in latency-bound workloads. However, it was removed by mistake together with VIRTIO_BLK_F_FLUSH. It will be restored in the next revision of the virtio 1.0 standard, so do the same in Linux. Signed-off-by: Paolo Bonzini <pbonzini at redhat.com> ---

Add a helper function for checking whether a bit is set in the guest features for a vdev as well as one that works on a feature bit set. Convert code that open-coded this: It cleans up the code and makes it easier to extend the guest feature bits. Signed-off-by: Cornelia Huck <cornelia.huck at de.ibm.com> --- hw/block/virtio-blk.c | 7 ++----- hw/char/virtio-serial-bus.c | 2

Add a helper function for checking whether a bit is set in the guest features for a vdev as well as one that works on a feature bit set. Convert code that open-coded this: It cleans up the code and makes it easier to extend the guest feature bits. Signed-off-by: Cornelia Huck <cornelia.huck at de.ibm.com> --- hw/block/virtio-blk.c | 7 ++----- hw/char/virtio-serial-bus.c | 2

Create a new attribute for virtio-blk devices that will fetch the serial number of the block device. This attribute can be used by udev to create disk/by-id symlinks for devices that don't have a UUID (filesystem) associated with them. ATA_IDENTIFY strings are special in that they can be up to 20 chars long and aren't required to be NULL-terminated. The buffer is also zero-padded

Create a new attribute for virtio-blk devices that will fetch the serial number of the block device. This attribute can be used by udev to create disk/by-id symlinks for devices that don't have a UUID (filesystem) associated with them. ATA_IDENTIFY strings are special in that they can be up to 20 chars long and aren't required to be NULL-terminated. The buffer is also zero-padded

Based on patch by Cornelia Huck. Note: for consistency, and to avoid sparse errors, convert all fields, even those no longer in use for virtio v1.0. Signed-off-by: Cornelia Huck <cornelia.huck at de.ibm.com> Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- include/uapi/linux/virtio_blk.h | 15 ++++----- drivers/block/virtio_blk.c | 70

Based on patch by Cornelia Huck. Note: for consistency, and to avoid sparse errors, convert all fields, even those no longer in use for virtio v1.0. Signed-off-by: Cornelia Huck <cornelia.huck at de.ibm.com> Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- include/uapi/linux/virtio_blk.h | 15 ++++----- drivers/block/virtio_blk.c | 70

Based on patch by Cornelia Huck. Note: for consistency, and to avoid sparse errors, convert all fields, even those no longer in use for virtio v1.0. Signed-off-by: Cornelia Huck <cornelia.huck at de.ibm.com> Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- include/uapi/linux/virtio_blk.h | 15 ++++----- drivers/block/virtio_blk.c | 70

Based on patch by Cornelia Huck. Note: for consistency, and to avoid sparse errors, convert all fields, even those no longer in use for virtio v1.0. Signed-off-by: Cornelia Huck <cornelia.huck at de.ibm.com> Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- include/uapi/linux/virtio_blk.h | 15 ++++----- drivers/block/virtio_blk.c | 70