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

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

Signed-off-by: David 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: Christian Brauner <brauner@kernel.org>
This commit is contained in:
David Howells 2024-07-26 22:20:54 +01:00 committed by Christian Brauner
parent 197a3de607
commit c45ebd636c
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GPG Key ID: 91C61BC06578DCA2
1 changed files with 68 additions and 3 deletions
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71
fs/smb/client/smbdirect.c
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@ -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--];