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authorAlex Elder <elder@dreamhost.com>2012-03-07 11:40:08 -0600
committerAlex Elder <elder@dreamhost.com>2012-03-22 10:47:52 -0500
commit8d63e318c4eb1bea6f7e3cb4b77849eaa167bfec (patch)
tree4783d4d0ab9a5d9c17e8eb0f93b0d279ad1b879a
parent9bd1966344bf975b5ce65e80fd6bacc41b4325a8 (diff)
downloadlinux-8d63e318c4eb1bea6f7e3cb4b77849eaa167bfec.tar.bz2
libceph: isolate kmap() call in write_partial_msg_pages()
In write_partial_msg_pages(), every case now does an identical call to kmap(page). Instead, just call it once inside the CRC-computing block where it's needed. Move the definition of kaddr inside that block, and make it a (char *) to ensure portable pointer arithmetic. We still don't kunmap() it until after the sendpage() call, in case that also ends up needing to use the mapping. Signed-off-by: Alex Elder <elder@dreamhost.com> Reviewed-by: Sage Weil <sage@newdream.net>
-rw-r--r--net/ceph/messenger.c13
1 files changed, 2 insertions, 11 deletions
diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index 2bf9ab4429e6..f0993af2ae4d 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -835,7 +835,6 @@ static int write_partial_msg_pages(struct ceph_connection *con)
while (data_len > con->out_msg_pos.data_pos) {
struct page *page = NULL;
- void *kaddr = NULL;
int max_write = PAGE_SIZE;
int bio_offset = 0;
@@ -856,18 +855,12 @@ static int write_partial_msg_pages(struct ceph_connection *con)
page = list_first_entry(&msg->trail->head,
struct page, lru);
- if (do_datacrc)
- kaddr = kmap(page);
max_write = PAGE_SIZE;
} else if (msg->pages) {
page = msg->pages[con->out_msg_pos.page];
- if (do_datacrc)
- kaddr = kmap(page);
} else if (msg->pagelist) {
page = list_first_entry(&msg->pagelist->head,
struct page, lru);
- if (do_datacrc)
- kaddr = kmap(page);
#ifdef CONFIG_BLOCK
} else if (msg->bio) {
struct bio_vec *bv;
@@ -875,14 +868,10 @@ static int write_partial_msg_pages(struct ceph_connection *con)
bv = bio_iovec_idx(msg->bio_iter, msg->bio_seg);
page = bv->bv_page;
bio_offset = bv->bv_offset;
- if (do_datacrc)
- kaddr = kmap(page);
max_write = bv->bv_len;
#endif
} else {
page = zero_page;
- if (do_datacrc)
- kaddr = kmap(page);
}
len = min_t(int, max_write - con->out_msg_pos.page_pos,
total_max_write);
@@ -891,7 +880,9 @@ static int write_partial_msg_pages(struct ceph_connection *con)
void *base;
u32 crc;
u32 tmpcrc = le32_to_cpu(con->out_msg->footer.data_crc);
+ char *kaddr;
+ kaddr = kmap(page);
BUG_ON(kaddr == NULL);
base = kaddr + con->out_msg_pos.page_pos + bio_offset;
crc = crc32c(tmpcrc, base, len);