[lustre-devel] [PATCH 05/45] lnet: always put a page list into struct lnet_libmd
James Simmons
jsimmons at infradead.org
Mon May 25 15:07:42 PDT 2020
From: Mr NeilBrown <neilb at suse.de>
'struct lnet_libmd' is only created in lnet_md_build(). It can be
given a list of pages or a virtual address. In the latter case, the
memory will eventually be split into a list of pages. It is cleaner
to split it into a list of pages early so that all lower levels only
need to handle one type: a page list.
WC-bug-id: https://jira.whamcloud.com/browse/LU-13004
Lustre-commit: 857f11169fc8 ("LU-13004 lnet: always put a page list into struct lnet_libmd")
Signed-off-by: Mr NeilBrown <neilb at suse.de>
Reviewed-on: https://review.whamcloud.com/37842
Reviewed-by: Shaun Tancheff <shaun.tancheff at hpe.com>
Reviewed-by: James Simmons <jsimmons at infradead.org>
Reviewed-by: Oleg Drokin <green at whamcloud.com>
Signed-off-by: James Simmons <jsimmons at infradead.org>
---
net/lnet/lnet/lib-md.c | 38 +++++++++++++++++++++++++-------------
1 file changed, 25 insertions(+), 13 deletions(-)
diff --git a/net/lnet/lnet/lib-md.c b/net/lnet/lnet/lib-md.c
index a9a83c3..e1b8a06 100644
--- a/net/lnet/lnet/lib-md.c
+++ b/net/lnet/lnet/lib-md.c
@@ -173,13 +173,12 @@ int lnet_cpt_of_md(struct lnet_libmd *md, unsigned int offset)
struct lnet_libmd *lmd;
unsigned int size;
- if ((umd->options & LNET_MD_KIOV) != 0) {
+ if (umd->options & LNET_MD_KIOV)
niov = umd->length;
- size = offsetof(struct lnet_libmd, md_iov.kiov[niov]);
- } else {
- niov = 1;
- size = offsetof(struct lnet_libmd, md_iov.iov[niov]);
- }
+ else
+ niov = DIV_ROUND_UP(offset_in_page(umd->start) + umd->length,
+ PAGE_SIZE);
+ size = offsetof(struct lnet_libmd, md_iov.kiov[niov]);
if (size <= LNET_SMALL_MD_SIZE) {
lmd = kmem_cache_zalloc(lnet_small_mds_cachep, GFP_NOFS);
@@ -200,7 +199,6 @@ int lnet_cpt_of_md(struct lnet_libmd *md, unsigned int offset)
lmd->md_niov = niov;
INIT_LIST_HEAD(&lmd->md_list);
-
lmd->md_me = NULL;
lmd->md_start = umd->start;
lmd->md_offset = 0;
@@ -238,19 +236,33 @@ int lnet_cpt_of_md(struct lnet_libmd *md, unsigned int offset)
lnet_md_free(lmd);
return ERR_PTR(-EINVAL);
}
- } else { /* contiguous */
- lmd->md_length = umd->length;
- niov = 1;
- lmd->md_niov = 1;
- lmd->md_iov.iov[0].iov_base = umd->start;
- lmd->md_iov.iov[0].iov_len = umd->length;
+ } else { /* contiguous - split into pages */
+ void *pa = umd->start;
+ int len = umd->length;
+ lmd->md_length = len;
+ i = 0;
+ while (len) {
+ int plen;
+
+ plen = min_t(int, len, PAGE_SIZE - offset_in_page(pa));
+
+ lmd->md_iov.kiov[i].bv_page =
+ lnet_kvaddr_to_page((unsigned long) pa);
+ lmd->md_iov.kiov[i].bv_offset = offset_in_page(pa);
+ lmd->md_iov.kiov[i].bv_len = plen;
+
+ len -= plen;
+ pa += plen;
+ i += 1;
+ }
if ((umd->options & LNET_MD_MAX_SIZE) && /* max size used */
(umd->max_size < 0 ||
umd->max_size > (int)umd->length)) { /* illegal max_size */
lnet_md_free(lmd);
return ERR_PTR(-EINVAL);
}
+ lmd->md_options |= LNET_MD_KIOV;
}
return lmd;
--
1.8.3.1
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