Paolo, thanks for the patch... On Wed, Sep 7, 2011 at 10:41 AM, Paolo Bonzini <pbonzini@xxxxxxxxxx> wrote: > Add a IOCTL to negotiate features between the server and the > kernel module (mediated by the usermode client). Features are > stored in the pre-existing flags field. I'm not crazy about another ioctl, but we need to get this flag setting functionality in, and I just have not had the time... > Also zero out the flags when NBD_DO_IT completes. > > Cc: Paul Clements <Paul.Clements@xxxxxxxxxxxx> > Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx> > --- > drivers/block/nbd.c | 8 ++++++++ > include/linux/nbd.h | 24 +++++++++++++++--------- > 2 files changed, 23 insertions(+), 9 deletions(-) > > diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c > index be23aec..c4fe9c8 100644 > --- a/drivers/block/nbd.c > +++ b/drivers/block/nbd.c > @@ -85,6 +85,7 @@ static const char *ioctl_cmd_to_ascii(int cmd) > case NBD_PRINT_DEBUG: return "print-debug"; > case NBD_SET_SIZE_BLOCKS: return "set-size-blocks"; > case NBD_DISCONNECT: return "disconnect"; > + case NBD_SET_FEATURES: return "set-features"; Could you name this as NBD_SET_FLAGS, as that's more consistent with what it's really doing? Otherwise these look good for inclusion. Thanks, Paul > case BLKROSET: return "set-read-only"; > case BLKFLSBUF: return "flush-buffer-cache"; > } > @@ -634,6 +635,12 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *lo, > lo->xmit_timeout = arg * HZ; > return 0; > > + case NBD_SET_FEATURES: > + if (((u64) arg) & NBD_FEATURE_RESERVED) > + return -EINVAL; > + lo->flags = (lo->flags & NBD_FEATURE_RESERVED) | (u64)arg; > + return 0; > + > case NBD_SET_SIZE_BLOCKS: > lo->bytesize = ((u64) arg) * lo->blksize; > bdev->bd_inode->i_size = lo->bytesize; > @@ -672,6 +679,7 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *lo, > printk(KERN_WARNING "%s: queue cleared\n", lo->disk->disk_name); > if (file) > fput(file); > + lo->flags = 0; > lo->bytesize = 0; > bdev->bd_inode->i_size = 0; > set_capacity(lo->disk, 0); > diff --git a/include/linux/nbd.h b/include/linux/nbd.h > index 0582054..926f19d 100644 > --- a/include/linux/nbd.h > +++ b/include/linux/nbd.h > @@ -17,16 +17,22 @@ > > #include <linux/types.h> > > -#define NBD_SET_SOCK _IO( 0xab, 0 ) > -#define NBD_SET_BLKSIZE _IO( 0xab, 1 ) > -#define NBD_SET_SIZE _IO( 0xab, 2 ) > -#define NBD_DO_IT _IO( 0xab, 3 ) > -#define NBD_CLEAR_SOCK _IO( 0xab, 4 ) > -#define NBD_CLEAR_QUE _IO( 0xab, 5 ) > -#define NBD_PRINT_DEBUG _IO( 0xab, 6 ) > -#define NBD_SET_SIZE_BLOCKS _IO( 0xab, 7 ) > -#define NBD_DISCONNECT _IO( 0xab, 8 ) > -#define NBD_SET_TIMEOUT _IO( 0xab, 9 ) > +#define NBD_SET_SOCK _IO(0xab, 0) > +#define NBD_SET_BLKSIZE _IO(0xab, 1) > +#define NBD_SET_SIZE _IO(0xab, 2) > +#define NBD_DO_IT _IO(0xab, 3) > +#define NBD_CLEAR_SOCK _IO(0xab, 4) > +#define NBD_CLEAR_QUE _IO(0xab, 5) > +#define NBD_PRINT_DEBUG _IO(0xab, 6) > +#define NBD_SET_SIZE_BLOCKS _IO(0xab, 7) > +#define NBD_DISCONNECT _IO(0xab, 8) > +#define NBD_SET_TIMEOUT _IO(0xab, 9) > +#define NBD_SET_FEATURES _IO(0xab, 10) > + > +/* bits 0 and 1 are already used for flags in the protocol, we do > + * not want any overlap. Bits 32-63 are reserved because they > + * are inaccessible on 32-bit platforms. */ > +#define NBD_FEATURE_RESERVED 0xFFFFFFFF00000003LL > > enum { > NBD_CMD_READ = 0, > -- > 1.7.6 > > > -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html