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[PATCH v6 5/5] loop: Add support for provision requests

Sarthak Kukreti posted 5 patches 2 years, 7 months ago
[PATCH v6 5/5] loop: Add support for provision requests
Posted by Sarthak Kukreti 2 years, 7 months ago 
Add support for provision requests to loopback devices.
Loop devices will configure provision support based on
whether the underlying block device/file can support
the provision request and upon receiving a provision bio,
will map it to the backing device/storage. For loop devices
over files, a REQ_OP_PROVISION request will translate to
an fallocate mode 0 call on the backing file.

Signed-off-by: Sarthak Kukreti <sarthakkukreti@chromium.org>
---
 drivers/block/loop.c | 42 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index bc31bb7072a2..13c4b4f8b9c1 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -327,6 +327,24 @@ static int lo_fallocate(struct loop_device *lo, struct request *rq, loff_t pos,
 	return ret;
 }
 
+static int lo_req_provision(struct loop_device *lo, struct request *rq, loff_t pos)
+{
+	struct file *file = lo->lo_backing_file;
+	struct request_queue *q = lo->lo_queue;
+	int ret;
+
+	if (!q->limits.max_provision_sectors) {
+		ret = -EOPNOTSUPP;
+		goto out;
+	}
+
+	ret = file->f_op->fallocate(file, 0, pos, blk_rq_bytes(rq));
+	if (unlikely(ret && ret != -EINVAL && ret != -EOPNOTSUPP))
+		ret = -EIO;
+ out:
+	return ret;
+}
+
 static int lo_req_flush(struct loop_device *lo, struct request *rq)
 {
 	int ret = vfs_fsync(lo->lo_backing_file, 0);
@@ -488,6 +506,8 @@ static int do_req_filebacked(struct loop_device *lo, struct request *rq)
 				FALLOC_FL_PUNCH_HOLE);
 	case REQ_OP_DISCARD:
 		return lo_fallocate(lo, rq, pos, FALLOC_FL_PUNCH_HOLE);
+	case REQ_OP_PROVISION:
+		return lo_req_provision(lo, rq, pos);
 	case REQ_OP_WRITE:
 		if (cmd->use_aio)
 			return lo_rw_aio(lo, cmd, pos, ITER_SOURCE);
@@ -754,6 +774,25 @@ static void loop_sysfs_exit(struct loop_device *lo)
 				   &loop_attribute_group);
 }
 
+static void loop_config_provision(struct loop_device *lo)
+{
+	struct file *file = lo->lo_backing_file;
+	struct inode *inode = file->f_mapping->host;
+
+	/*
+	 * If the backing device is a block device, mirror its provisioning
+	 * capability.
+	 */
+	if (S_ISBLK(inode->i_mode)) {
+		blk_queue_max_provision_sectors(lo->lo_queue,
+			bdev_max_provision_sectors(I_BDEV(inode)));
+	} else if (file->f_op->fallocate) {
+		blk_queue_max_provision_sectors(lo->lo_queue, UINT_MAX >> 9);
+	} else {
+		blk_queue_max_provision_sectors(lo->lo_queue, 0);
+	}
+}
+
 static void loop_config_discard(struct loop_device *lo)
 {
 	struct file *file = lo->lo_backing_file;
@@ -1092,6 +1131,7 @@ static int loop_configure(struct loop_device *lo, fmode_t mode,
 	blk_queue_io_min(lo->lo_queue, bsize);
 
 	loop_config_discard(lo);
+	loop_config_provision(lo);
 	loop_update_rotational(lo);
 	loop_update_dio(lo);
 	loop_sysfs_init(lo);
@@ -1304,6 +1344,7 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info)
 	}
 
 	loop_config_discard(lo);
+	loop_config_provision(lo);
 
 	/* update dio if lo_offset or transfer is changed */
 	__loop_update_dio(lo, lo->use_dio);
@@ -1830,6 +1871,7 @@ static blk_status_t loop_queue_rq(struct blk_mq_hw_ctx *hctx,
 	case REQ_OP_FLUSH:
 	case REQ_OP_DISCARD:
 	case REQ_OP_WRITE_ZEROES:
+	case REQ_OP_PROVISION:
 		cmd->use_aio = false;
 		break;
 	default:
-- 
2.40.1.521.gf1e218fcd8-goog
Re: [PATCH v6 5/5] loop: Add support for provision requests
Posted by Brian Foster 2 years, 7 months ago 
On Fri, May 05, 2023 at 11:29:09PM -0700, Sarthak Kukreti wrote:
> Add support for provision requests to loopback devices.
> Loop devices will configure provision support based on
> whether the underlying block device/file can support
> the provision request and upon receiving a provision bio,
> will map it to the backing device/storage. For loop devices
> over files, a REQ_OP_PROVISION request will translate to
> an fallocate mode 0 call on the backing file.
> 
> Signed-off-by: Sarthak Kukreti <sarthakkukreti@chromium.org>
> ---
>  drivers/block/loop.c | 42 ++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 42 insertions(+)
> 
> diff --git a/drivers/block/loop.c b/drivers/block/loop.c
> index bc31bb7072a2..13c4b4f8b9c1 100644
> --- a/drivers/block/loop.c
> +++ b/drivers/block/loop.c
> @@ -327,6 +327,24 @@ static int lo_fallocate(struct loop_device *lo, struct request *rq, loff_t pos,
>  	return ret;
>  }
>  
> +static int lo_req_provision(struct loop_device *lo, struct request *rq, loff_t pos)
> +{
> +	struct file *file = lo->lo_backing_file;
> +	struct request_queue *q = lo->lo_queue;
> +	int ret;
> +
> +	if (!q->limits.max_provision_sectors) {
> +		ret = -EOPNOTSUPP;
> +		goto out;
> +	}
> +
> +	ret = file->f_op->fallocate(file, 0, pos, blk_rq_bytes(rq));
> +	if (unlikely(ret && ret != -EINVAL && ret != -EOPNOTSUPP))
> +		ret = -EIO;
> + out:
> +	return ret;
> +}
> +
>  static int lo_req_flush(struct loop_device *lo, struct request *rq)
>  {
>  	int ret = vfs_fsync(lo->lo_backing_file, 0);
> @@ -488,6 +506,8 @@ static int do_req_filebacked(struct loop_device *lo, struct request *rq)
>  				FALLOC_FL_PUNCH_HOLE);
>  	case REQ_OP_DISCARD:
>  		return lo_fallocate(lo, rq, pos, FALLOC_FL_PUNCH_HOLE);
> +	case REQ_OP_PROVISION:
> +		return lo_req_provision(lo, rq, pos);

Hi Sarthak,

The only thing that stands out to me is the separate lo_req_provision()
helper here. It seems it might be a little cleaner to extend and reuse
lo_req_fallocate()..? But that's not something I feel strongly about, so
this all looks pretty good to me either way, FWIW.

Brian

>  	case REQ_OP_WRITE:
>  		if (cmd->use_aio)
>  			return lo_rw_aio(lo, cmd, pos, ITER_SOURCE);
> @@ -754,6 +774,25 @@ static void loop_sysfs_exit(struct loop_device *lo)
>  				   &loop_attribute_group);
>  }
>  
> +static void loop_config_provision(struct loop_device *lo)
> +{
> +	struct file *file = lo->lo_backing_file;
> +	struct inode *inode = file->f_mapping->host;
> +
> +	/*
> +	 * If the backing device is a block device, mirror its provisioning
> +	 * capability.
> +	 */
> +	if (S_ISBLK(inode->i_mode)) {
> +		blk_queue_max_provision_sectors(lo->lo_queue,
> +			bdev_max_provision_sectors(I_BDEV(inode)));
> +	} else if (file->f_op->fallocate) {
> +		blk_queue_max_provision_sectors(lo->lo_queue, UINT_MAX >> 9);
> +	} else {
> +		blk_queue_max_provision_sectors(lo->lo_queue, 0);
> +	}
> +}
> +
>  static void loop_config_discard(struct loop_device *lo)
>  {
>  	struct file *file = lo->lo_backing_file;
> @@ -1092,6 +1131,7 @@ static int loop_configure(struct loop_device *lo, fmode_t mode,
>  	blk_queue_io_min(lo->lo_queue, bsize);
>  
>  	loop_config_discard(lo);
> +	loop_config_provision(lo);
>  	loop_update_rotational(lo);
>  	loop_update_dio(lo);
>  	loop_sysfs_init(lo);
> @@ -1304,6 +1344,7 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info)
>  	}
>  
>  	loop_config_discard(lo);
> +	loop_config_provision(lo);
>  
>  	/* update dio if lo_offset or transfer is changed */
>  	__loop_update_dio(lo, lo->use_dio);
> @@ -1830,6 +1871,7 @@ static blk_status_t loop_queue_rq(struct blk_mq_hw_ctx *hctx,
>  	case REQ_OP_FLUSH:
>  	case REQ_OP_DISCARD:
>  	case REQ_OP_WRITE_ZEROES:
> +	case REQ_OP_PROVISION:
>  		cmd->use_aio = false;
>  		break;
>  	default:
> -- 
> 2.40.1.521.gf1e218fcd8-goog
>
Re: [PATCH v6 5/5] loop: Add support for provision requests
Posted by Sarthak Kukreti 2 years, 7 months ago 
On Mon, May 15, 2023 at 5:37 AM Brian Foster <bfoster@redhat.com> wrote:
>
> On Fri, May 05, 2023 at 11:29:09PM -0700, Sarthak Kukreti wrote:
> > Add support for provision requests to loopback devices.
> > Loop devices will configure provision support based on
> > whether the underlying block device/file can support
> > the provision request and upon receiving a provision bio,
> > will map it to the backing device/storage. For loop devices
> > over files, a REQ_OP_PROVISION request will translate to
> > an fallocate mode 0 call on the backing file.
> >
> > Signed-off-by: Sarthak Kukreti <sarthakkukreti@chromium.org>
> > ---
> >  drivers/block/loop.c | 42 ++++++++++++++++++++++++++++++++++++++++++
> >  1 file changed, 42 insertions(+)
> >
> > diff --git a/drivers/block/loop.c b/drivers/block/loop.c
> > index bc31bb7072a2..13c4b4f8b9c1 100644
> > --- a/drivers/block/loop.c
> > +++ b/drivers/block/loop.c
> > @@ -327,6 +327,24 @@ static int lo_fallocate(struct loop_device *lo, struct request *rq, loff_t pos,
> >       return ret;
> >  }
> >
> > +static int lo_req_provision(struct loop_device *lo, struct request *rq, loff_t pos)
> > +{
> > +     struct file *file = lo->lo_backing_file;
> > +     struct request_queue *q = lo->lo_queue;
> > +     int ret;
> > +
> > +     if (!q->limits.max_provision_sectors) {
> > +             ret = -EOPNOTSUPP;
> > +             goto out;
> > +     }
> > +
> > +     ret = file->f_op->fallocate(file, 0, pos, blk_rq_bytes(rq));
> > +     if (unlikely(ret && ret != -EINVAL && ret != -EOPNOTSUPP))
> > +             ret = -EIO;
> > + out:
> > +     return ret;
> > +}
> > +
> >  static int lo_req_flush(struct loop_device *lo, struct request *rq)
> >  {
> >       int ret = vfs_fsync(lo->lo_backing_file, 0);
> > @@ -488,6 +506,8 @@ static int do_req_filebacked(struct loop_device *lo, struct request *rq)
> >                               FALLOC_FL_PUNCH_HOLE);
> >       case REQ_OP_DISCARD:
> >               return lo_fallocate(lo, rq, pos, FALLOC_FL_PUNCH_HOLE);
> > +     case REQ_OP_PROVISION:
> > +             return lo_req_provision(lo, rq, pos);
>
> Hi Sarthak,
>
> The only thing that stands out to me is the separate lo_req_provision()
> helper here. It seems it might be a little cleaner to extend and reuse
> lo_req_fallocate()..? But that's not something I feel strongly about, so
> this all looks pretty good to me either way, FWIW.
>
Fair point, I think that should shorten the patch (and for
correctness, we'd want to add FALLOC_FL_KEEP_SIZE for REQ_OP_PROVISION
too). I'll fix this up in v7.

Best
Sarthak

> Brian
>
> >       case REQ_OP_WRITE:
> >               if (cmd->use_aio)
> >                       return lo_rw_aio(lo, cmd, pos, ITER_SOURCE);
> > @@ -754,6 +774,25 @@ static void loop_sysfs_exit(struct loop_device *lo)
> >                                  &loop_attribute_group);
> >  }
> >
> > +static void loop_config_provision(struct loop_device *lo)
> > +{
> > +     struct file *file = lo->lo_backing_file;
> > +     struct inode *inode = file->f_mapping->host;
> > +
> > +     /*
> > +      * If the backing device is a block device, mirror its provisioning
> > +      * capability.
> > +      */
> > +     if (S_ISBLK(inode->i_mode)) {
> > +             blk_queue_max_provision_sectors(lo->lo_queue,
> > +                     bdev_max_provision_sectors(I_BDEV(inode)));
> > +     } else if (file->f_op->fallocate) {
> > +             blk_queue_max_provision_sectors(lo->lo_queue, UINT_MAX >> 9);
> > +     } else {
> > +             blk_queue_max_provision_sectors(lo->lo_queue, 0);
> > +     }
> > +}
> > +
> >  static void loop_config_discard(struct loop_device *lo)
> >  {
> >       struct file *file = lo->lo_backing_file;
> > @@ -1092,6 +1131,7 @@ static int loop_configure(struct loop_device *lo, fmode_t mode,
> >       blk_queue_io_min(lo->lo_queue, bsize);
> >
> >       loop_config_discard(lo);
> > +     loop_config_provision(lo);
> >       loop_update_rotational(lo);
> >       loop_update_dio(lo);
> >       loop_sysfs_init(lo);
> > @@ -1304,6 +1344,7 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info)
> >       }
> >
> >       loop_config_discard(lo);
> > +     loop_config_provision(lo);
> >
> >       /* update dio if lo_offset or transfer is changed */
> >       __loop_update_dio(lo, lo->use_dio);
> > @@ -1830,6 +1871,7 @@ static blk_status_t loop_queue_rq(struct blk_mq_hw_ctx *hctx,
> >       case REQ_OP_FLUSH:
> >       case REQ_OP_DISCARD:
> >       case REQ_OP_WRITE_ZEROES:
> > +     case REQ_OP_PROVISION:
> >               cmd->use_aio = false;
> >               break;
> >       default:
> > --
> > 2.40.1.521.gf1e218fcd8-goog
> >
>

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