mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-10-27 14:45:19 +00:00
cifs: Add a function to build an RDMA SGE list from an iterator
Add a function to add elements onto an RDMA SGE list representing page fragments extracted from a BVEC-, KVEC- or XARRAY-type iterator and DMA mapped until the maximum number of elements is reached. Nothing is done to make sure the pages remain present - that must be done by the caller. Signed-off-by: David Howells <dhowells@redhat.com> cc: Steve French <sfrench@samba.org> cc: Shyam Prasad N <nspmangalore@gmail.com> cc: Rohith Surabattula <rohiths.msft@gmail.com> cc: Tom Talpey <tom@talpey.com> cc: Jeff Layton <jlayton@kernel.org> cc: linux-cifs@vger.kernel.org cc: linux-fsdevel@vger.kernel.org cc: linux-rdma@vger.kernel.org Link: https://lore.kernel.org/r/166697256704.61150.17388516338310645808.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/166732028840.3186319.8512284239779728860.stgit@warthog.procyon.org.uk/ # rfc Signed-off-by: Steve French <stfrench@microsoft.com>
This commit is contained in:
parent
0185846975
commit
e5fbdde430
1 changed files with 214 additions and 0 deletions
|
@ -44,6 +44,17 @@ static int smbd_post_send_page(struct smbd_connection *info,
|
||||||
static void destroy_mr_list(struct smbd_connection *info);
|
static void destroy_mr_list(struct smbd_connection *info);
|
||||||
static int allocate_mr_list(struct smbd_connection *info);
|
static int allocate_mr_list(struct smbd_connection *info);
|
||||||
|
|
||||||
|
struct smb_extract_to_rdma {
|
||||||
|
struct ib_sge *sge;
|
||||||
|
unsigned int nr_sge;
|
||||||
|
unsigned int max_sge;
|
||||||
|
struct ib_device *device;
|
||||||
|
u32 local_dma_lkey;
|
||||||
|
enum dma_data_direction direction;
|
||||||
|
};
|
||||||
|
static ssize_t smb_extract_iter_to_rdma(struct iov_iter *iter, size_t len,
|
||||||
|
struct smb_extract_to_rdma *rdma);
|
||||||
|
|
||||||
/* SMBD version number */
|
/* SMBD version number */
|
||||||
#define SMBD_V1 0x0100
|
#define SMBD_V1 0x0100
|
||||||
|
|
||||||
|
@ -2492,3 +2503,206 @@ int smbd_deregister_mr(struct smbd_mr *smbdirect_mr)
|
||||||
|
|
||||||
return rc;
|
return rc;
|
||||||
}
|
}
|
||||||
|
|
||||||
|
static bool smb_set_sge(struct smb_extract_to_rdma *rdma,
|
||||||
|
struct page *lowest_page, size_t off, size_t len)
|
||||||
|
{
|
||||||
|
struct ib_sge *sge = &rdma->sge[rdma->nr_sge];
|
||||||
|
u64 addr;
|
||||||
|
|
||||||
|
addr = ib_dma_map_page(rdma->device, lowest_page,
|
||||||
|
off, len, rdma->direction);
|
||||||
|
if (ib_dma_mapping_error(rdma->device, addr))
|
||||||
|
return false;
|
||||||
|
|
||||||
|
sge->addr = addr;
|
||||||
|
sge->length = len;
|
||||||
|
sge->lkey = rdma->local_dma_lkey;
|
||||||
|
rdma->nr_sge++;
|
||||||
|
return true;
|
||||||
|
}
|
||||||
|
|
||||||
|
/*
|
||||||
|
* Extract page fragments from a BVEC-class iterator and add them to an RDMA
|
||||||
|
* element list. The pages are not pinned.
|
||||||
|
*/
|
||||||
|
static ssize_t smb_extract_bvec_to_rdma(struct iov_iter *iter,
|
||||||
|
struct smb_extract_to_rdma *rdma,
|
||||||
|
ssize_t maxsize)
|
||||||
|
{
|
||||||
|
const struct bio_vec *bv = iter->bvec;
|
||||||
|
unsigned long start = iter->iov_offset;
|
||||||
|
unsigned int i;
|
||||||
|
ssize_t ret = 0;
|
||||||
|
|
||||||
|
for (i = 0; i < iter->nr_segs; i++) {
|
||||||
|
size_t off, len;
|
||||||
|
|
||||||
|
len = bv[i].bv_len;
|
||||||
|
if (start >= len) {
|
||||||
|
start -= len;
|
||||||
|
continue;
|
||||||
|
}
|
||||||
|
|
||||||
|
len = min_t(size_t, maxsize, len - start);
|
||||||
|
off = bv[i].bv_offset + start;
|
||||||
|
|
||||||
|
if (!smb_set_sge(rdma, bv[i].bv_page, off, len))
|
||||||
|
return -EIO;
|
||||||
|
|
||||||
|
ret += len;
|
||||||
|
maxsize -= len;
|
||||||
|
if (rdma->nr_sge >= rdma->max_sge || maxsize <= 0)
|
||||||
|
break;
|
||||||
|
start = 0;
|
||||||
|
}
|
||||||
|
|
||||||
|
return ret;
|
||||||
|
}
|
||||||
|
|
||||||
|
/*
|
||||||
|
* Extract fragments from a KVEC-class iterator and add them to an RDMA list.
|
||||||
|
* This can deal with vmalloc'd buffers as well as kmalloc'd or static buffers.
|
||||||
|
* The pages are not pinned.
|
||||||
|
*/
|
||||||
|
static ssize_t smb_extract_kvec_to_rdma(struct iov_iter *iter,
|
||||||
|
struct smb_extract_to_rdma *rdma,
|
||||||
|
ssize_t maxsize)
|
||||||
|
{
|
||||||
|
const struct kvec *kv = iter->kvec;
|
||||||
|
unsigned long start = iter->iov_offset;
|
||||||
|
unsigned int i;
|
||||||
|
ssize_t ret = 0;
|
||||||
|
|
||||||
|
for (i = 0; i < iter->nr_segs; i++) {
|
||||||
|
struct page *page;
|
||||||
|
unsigned long kaddr;
|
||||||
|
size_t off, len, seg;
|
||||||
|
|
||||||
|
len = kv[i].iov_len;
|
||||||
|
if (start >= len) {
|
||||||
|
start -= len;
|
||||||
|
continue;
|
||||||
|
}
|
||||||
|
|
||||||
|
kaddr = (unsigned long)kv[i].iov_base + start;
|
||||||
|
off = kaddr & ~PAGE_MASK;
|
||||||
|
len = min_t(size_t, maxsize, len - start);
|
||||||
|
kaddr &= PAGE_MASK;
|
||||||
|
|
||||||
|
maxsize -= len;
|
||||||
|
do {
|
||||||
|
seg = min_t(size_t, len, PAGE_SIZE - off);
|
||||||
|
|
||||||
|
if (is_vmalloc_or_module_addr((void *)kaddr))
|
||||||
|
page = vmalloc_to_page((void *)kaddr);
|
||||||
|
else
|
||||||
|
page = virt_to_page(kaddr);
|
||||||
|
|
||||||
|
if (!smb_set_sge(rdma, page, off, seg))
|
||||||
|
return -EIO;
|
||||||
|
|
||||||
|
ret += seg;
|
||||||
|
len -= seg;
|
||||||
|
kaddr += PAGE_SIZE;
|
||||||
|
off = 0;
|
||||||
|
} while (len > 0 && rdma->nr_sge < rdma->max_sge);
|
||||||
|
|
||||||
|
if (rdma->nr_sge >= rdma->max_sge || maxsize <= 0)
|
||||||
|
break;
|
||||||
|
start = 0;
|
||||||
|
}
|
||||||
|
|
||||||
|
return ret;
|
||||||
|
}
|
||||||
|
|
||||||
|
/*
|
||||||
|
* Extract folio fragments from an XARRAY-class iterator and add them to an
|
||||||
|
* RDMA list. The folios are not pinned.
|
||||||
|
*/
|
||||||
|
static ssize_t smb_extract_xarray_to_rdma(struct iov_iter *iter,
|
||||||
|
struct smb_extract_to_rdma *rdma,
|
||||||
|
ssize_t maxsize)
|
||||||
|
{
|
||||||
|
struct xarray *xa = iter->xarray;
|
||||||
|
struct folio *folio;
|
||||||
|
loff_t start = iter->xarray_start + iter->iov_offset;
|
||||||
|
pgoff_t index = start / PAGE_SIZE;
|
||||||
|
ssize_t ret = 0;
|
||||||
|
size_t off, len;
|
||||||
|
XA_STATE(xas, xa, index);
|
||||||
|
|
||||||
|
rcu_read_lock();
|
||||||
|
|
||||||
|
xas_for_each(&xas, folio, ULONG_MAX) {
|
||||||
|
if (xas_retry(&xas, folio))
|
||||||
|
continue;
|
||||||
|
if (WARN_ON(xa_is_value(folio)))
|
||||||
|
break;
|
||||||
|
if (WARN_ON(folio_test_hugetlb(folio)))
|
||||||
|
break;
|
||||||
|
|
||||||
|
off = offset_in_folio(folio, start);
|
||||||
|
len = min_t(size_t, maxsize, folio_size(folio) - off);
|
||||||
|
|
||||||
|
if (!smb_set_sge(rdma, folio_page(folio, 0), off, len)) {
|
||||||
|
rcu_read_unlock();
|
||||||
|
return -EIO;
|
||||||
|
}
|
||||||
|
|
||||||
|
maxsize -= len;
|
||||||
|
ret += len;
|
||||||
|
if (rdma->nr_sge >= rdma->max_sge || maxsize <= 0)
|
||||||
|
break;
|
||||||
|
}
|
||||||
|
|
||||||
|
rcu_read_unlock();
|
||||||
|
return ret;
|
||||||
|
}
|
||||||
|
|
||||||
|
/*
|
||||||
|
* Extract page fragments from up to the given amount of the source iterator
|
||||||
|
* and build up an RDMA list that refers to all of those bits. The RDMA list
|
||||||
|
* is appended to, up to the maximum number of elements set in the parameter
|
||||||
|
* block.
|
||||||
|
*
|
||||||
|
* The extracted page fragments are not pinned or ref'd in any way; if an
|
||||||
|
* IOVEC/UBUF-type iterator is to be used, it should be converted to a
|
||||||
|
* BVEC-type iterator and the pages pinned, ref'd or otherwise held in some
|
||||||
|
* way.
|
||||||
|
*/
|
||||||
|
static ssize_t smb_extract_iter_to_rdma(struct iov_iter *iter, size_t len,
|
||||||
|
struct smb_extract_to_rdma *rdma)
|
||||||
|
{
|
||||||
|
ssize_t ret;
|
||||||
|
int before = rdma->nr_sge;
|
||||||
|
|
||||||
|
switch (iov_iter_type(iter)) {
|
||||||
|
case ITER_BVEC:
|
||||||
|
ret = smb_extract_bvec_to_rdma(iter, rdma, len);
|
||||||
|
break;
|
||||||
|
case ITER_KVEC:
|
||||||
|
ret = smb_extract_kvec_to_rdma(iter, rdma, len);
|
||||||
|
break;
|
||||||
|
case ITER_XARRAY:
|
||||||
|
ret = smb_extract_xarray_to_rdma(iter, rdma, len);
|
||||||
|
break;
|
||||||
|
default:
|
||||||
|
WARN_ON_ONCE(1);
|
||||||
|
return -EIO;
|
||||||
|
}
|
||||||
|
|
||||||
|
if (ret > 0) {
|
||||||
|
iov_iter_advance(iter, ret);
|
||||||
|
} else if (ret < 0) {
|
||||||
|
while (rdma->nr_sge > before) {
|
||||||
|
struct ib_sge *sge = &rdma->sge[rdma->nr_sge--];
|
||||||
|
|
||||||
|
ib_dma_unmap_single(rdma->device, sge->addr, sge->length,
|
||||||
|
rdma->direction);
|
||||||
|
sge->addr = 0;
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
return ret;
|
||||||
|
}
|
||||||
|
|
Loading…
Reference in a new issue