Unverified Commit c45ebd63 authored by David Howells's avatar David Howells Committed by Christian Brauner
Browse files

cifs: Provide the capability to extract from ITER_FOLIOQ to RDMA SGEs 



Make smb_extract_iter_to_rdma() extract page fragments from an ITER_FOLIOQ
iterator into RDMA SGEs.

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
cc: Steve French <sfrench@samba.org>
cc: Paulo Alcantara <pc@manguebit.com>
cc: Tom Talpey <tom@talpey.com>
cc: Enzo Matsumiya <ematsumiya@suse.de>
cc: linux-cifs@vger.kernel.org
Link: https://lore.kernel.org/r/20240814203850.2240469-15-dhowells@redhat.com/

 # v2
Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent 197a3de6

fs/smb/client/smbdirect.c

+68 −3
Original line number Diff line number Diff line
@@ -6,6 +6,7 @@ 
 */

#include <linux/module.h>

#include <linux/highmem.h>

#include <linux/folio_queue.h>

#include "smbdirect.h"

#include "cifs_debug.h"

#include "cifsproto.h"
@@ -2463,6 +2464,8 @@ static ssize_t smb_extract_bvec_to_rdma(struct iov_iter *iter, 
		start = 0;

	}



	if (ret > 0)

		iov_iter_advance(iter, ret);

	return ret;

}
@@ -2519,6 +2522,65 @@ static ssize_t smb_extract_kvec_to_rdma(struct iov_iter *iter, 
		start = 0;

	}



	if (ret > 0)

		iov_iter_advance(iter, ret);

	return ret;

}



/*

 * Extract folio fragments from a FOLIOQ-class iterator and add them to an RDMA

 * list.  The folios are not pinned.

 */

static ssize_t smb_extract_folioq_to_rdma(struct iov_iter *iter,

					  struct smb_extract_to_rdma *rdma,

					  ssize_t maxsize)

{

	const struct folio_queue *folioq = iter->folioq;

	unsigned int slot = iter->folioq_slot;

	ssize_t ret = 0;

	size_t offset = iter->iov_offset;



	BUG_ON(!folioq);



	if (slot >= folioq_nr_slots(folioq)) {

		folioq = folioq->next;

		if (WARN_ON_ONCE(!folioq))

			return -EIO;

		slot = 0;

	}



	do {

		struct folio *folio = folioq_folio(folioq, slot);

		size_t fsize = folioq_folio_size(folioq, slot);



		if (offset < fsize) {

			size_t part = umin(maxsize - ret, fsize - offset);



			if (!smb_set_sge(rdma, folio_page(folio, 0), offset, part))

				return -EIO;



			offset += part;

			ret += part;

		}



		if (offset >= fsize) {

			offset = 0;

			slot++;

			if (slot >= folioq_nr_slots(folioq)) {

				if (!folioq->next) {

					WARN_ON_ONCE(ret < iter->count);

					break;

				}

				folioq = folioq->next;

				slot = 0;

			}

		}

	} while (rdma->nr_sge < rdma->max_sge || maxsize > 0);



	iter->folioq = folioq;

	iter->folioq_slot = slot;

	iter->iov_offset = offset;

	iter->count -= ret;

	return ret;

}
@@ -2563,6 +2625,8 @@ static ssize_t smb_extract_xarray_to_rdma(struct iov_iter *iter, 
	}



	rcu_read_unlock();

	if (ret > 0)

		iov_iter_advance(iter, ret);

	return ret;

}
@@ -2590,6 +2654,9 @@ static ssize_t smb_extract_iter_to_rdma(struct iov_iter *iter, size_t len, 
	case ITER_KVEC:

		ret = smb_extract_kvec_to_rdma(iter, rdma, len);

		break;

	case ITER_FOLIOQ:

		ret = smb_extract_folioq_to_rdma(iter, rdma, len);

		break;

	case ITER_XARRAY:

		ret = smb_extract_xarray_to_rdma(iter, rdma, len);

		break;
@@ -2598,9 +2665,7 @@ static ssize_t smb_extract_iter_to_rdma(struct iov_iter *iter, size_t len, 
		return -EIO;

	}



	if (ret > 0) {

		iov_iter_advance(iter, ret);

	} else if (ret < 0) {

	if (ret < 0) {

		while (rdma->nr_sge > before) {

			struct ib_sge *sge = &rdma->sge[rdma->nr_sge--];