diff mbox series

[v7,5/5] loop: Add support for provision requests

Message ID 20230518223326.18744-6-sarthakkukreti@chromium.org (mailing list archive)
State Superseded, archived
Delegated to: Mike Snitzer
Headers show
Series Introduce provisioning primitives | expand

Commit Message

Sarthak Kukreti May 18, 2023, 10:33 p.m. UTC 
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 | 34 +++++++++++++++++++++++++++++++---
 1 file changed, 31 insertions(+), 3 deletions(-)

Comments

Darrick J. Wong May 22, 2023, 4:37 p.m. UTC | #1 
On Thu, May 18, 2023 at 03:33:26PM -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 | 34 +++++++++++++++++++++++++++++++---
>  1 file changed, 31 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/block/loop.c b/drivers/block/loop.c
> index bc31bb7072a2..7fe1a6629754 100644
> --- a/drivers/block/loop.c
> +++ b/drivers/block/loop.c
> @@ -311,16 +311,20 @@ static int lo_fallocate(struct loop_device *lo, struct request *rq, loff_t pos,
>  {
>  	/*
>  	 * We use fallocate to manipulate the space mappings used by the image
> -	 * a.k.a. discard/zerorange.
> +	 * a.k.a. discard/provision/zerorange.
>  	 */
>  	struct file *file = lo->lo_backing_file;
>  	int ret;
>  
> -	mode |= FALLOC_FL_KEEP_SIZE;
> +	if (mode & (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_ZERO_RANGE) &&
> +	    !bdev_max_discard_sectors(lo->lo_device))
> +		return -EOPNOTSUPP;
>  
> -	if (!bdev_max_discard_sectors(lo->lo_device))
> +	if (mode == 0 && !bdev_max_provision_sectors(lo->lo_device))
>  		return -EOPNOTSUPP;
>  
> +	mode |= FALLOC_FL_KEEP_SIZE;
> +
>  	ret = file->f_op->fallocate(file, mode, pos, blk_rq_bytes(rq));
>  	if (unlikely(ret && ret != -EINVAL && ret != -EOPNOTSUPP))
>  		return -EIO;
> @@ -488,6 +492,8 @@ 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_fallocate(lo, rq, pos, 0);

If someone calls fallocate(UNSHARE_RANGE) on a loop bdev, shouldn't
there be a way to pass that through to the fallocate call to the backing
file?

--D

>  	case REQ_OP_WRITE:
>  		if (cmd->use_aio)
>  			return lo_rw_aio(lo, cmd, pos, ITER_SOURCE);
> @@ -754,6 +760,25 @@ 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 +1117,7 @@ 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 +1330,7 @@ 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 +1857,7 @@ 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:
> -- 
> 2.40.1.698.g37aff9b760-goog
> 
> --
> dm-devel mailing list
> dm-devel@redhat.com
> https://listman.redhat.com/mailman/listinfo/dm-devel
> 

--
dm-devel mailing list
dm-devel@redhat.com
https://listman.redhat.com/mailman/listinfo/dm-devel
diff mbox series

Patch

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index bc31bb7072a2..7fe1a6629754 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -311,16 +311,20 @@  static int lo_fallocate(struct loop_device *lo, struct request *rq, loff_t pos,
 {
 	/*
 	 * We use fallocate to manipulate the space mappings used by the image
-	 * a.k.a. discard/zerorange.
+	 * a.k.a. discard/provision/zerorange.
 	 */
 	struct file *file = lo->lo_backing_file;
 	int ret;
 
-	mode |= FALLOC_FL_KEEP_SIZE;
+	if (mode & (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_ZERO_RANGE) &&
+	    !bdev_max_discard_sectors(lo->lo_device))
+		return -EOPNOTSUPP;
 
-	if (!bdev_max_discard_sectors(lo->lo_device))
+	if (mode == 0 && !bdev_max_provision_sectors(lo->lo_device))
 		return -EOPNOTSUPP;
 
+	mode |= FALLOC_FL_KEEP_SIZE;
+
 	ret = file->f_op->fallocate(file, mode, pos, blk_rq_bytes(rq));
 	if (unlikely(ret && ret != -EINVAL && ret != -EOPNOTSUPP))
 		return -EIO;
@@ -488,6 +492,8 @@  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_fallocate(lo, rq, pos, 0);
 	case REQ_OP_WRITE:
 		if (cmd->use_aio)
 			return lo_rw_aio(lo, cmd, pos, ITER_SOURCE);
@@ -754,6 +760,25 @@  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 +1117,7 @@  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 +1330,7 @@  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 +1857,7 @@  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: