Commit 8d63e318 authored by Alex Elder's avatar Alex Elder

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: default avatarAlex Elder <elder@dreamhost.com>
Reviewed-by: default avatarSage Weil <sage@newdream.net>
parent 9bd19663
...@@ -835,7 +835,6 @@ static int write_partial_msg_pages(struct ceph_connection *con) ...@@ -835,7 +835,6 @@ static int write_partial_msg_pages(struct ceph_connection *con)
while (data_len > con->out_msg_pos.data_pos) { while (data_len > con->out_msg_pos.data_pos) {
struct page *page = NULL; struct page *page = NULL;
void *kaddr = NULL;
int max_write = PAGE_SIZE; int max_write = PAGE_SIZE;
int bio_offset = 0; int bio_offset = 0;
...@@ -856,18 +855,12 @@ static int write_partial_msg_pages(struct ceph_connection *con) ...@@ -856,18 +855,12 @@ static int write_partial_msg_pages(struct ceph_connection *con)
page = list_first_entry(&msg->trail->head, page = list_first_entry(&msg->trail->head,
struct page, lru); struct page, lru);
if (do_datacrc)
kaddr = kmap(page);
max_write = PAGE_SIZE; max_write = PAGE_SIZE;
} else if (msg->pages) { } else if (msg->pages) {
page = msg->pages[con->out_msg_pos.page]; page = msg->pages[con->out_msg_pos.page];
if (do_datacrc)
kaddr = kmap(page);
} else if (msg->pagelist) { } else if (msg->pagelist) {
page = list_first_entry(&msg->pagelist->head, page = list_first_entry(&msg->pagelist->head,
struct page, lru); struct page, lru);
if (do_datacrc)
kaddr = kmap(page);
#ifdef CONFIG_BLOCK #ifdef CONFIG_BLOCK
} else if (msg->bio) { } else if (msg->bio) {
struct bio_vec *bv; struct bio_vec *bv;
...@@ -875,14 +868,10 @@ static int write_partial_msg_pages(struct ceph_connection *con) ...@@ -875,14 +868,10 @@ static int write_partial_msg_pages(struct ceph_connection *con)
bv = bio_iovec_idx(msg->bio_iter, msg->bio_seg); bv = bio_iovec_idx(msg->bio_iter, msg->bio_seg);
page = bv->bv_page; page = bv->bv_page;
bio_offset = bv->bv_offset; bio_offset = bv->bv_offset;
if (do_datacrc)
kaddr = kmap(page);
max_write = bv->bv_len; max_write = bv->bv_len;
#endif #endif
} else { } else {
page = zero_page; page = zero_page;
if (do_datacrc)
kaddr = kmap(page);
} }
len = min_t(int, max_write - con->out_msg_pos.page_pos, len = min_t(int, max_write - con->out_msg_pos.page_pos,
total_max_write); total_max_write);
...@@ -891,7 +880,9 @@ static int write_partial_msg_pages(struct ceph_connection *con) ...@@ -891,7 +880,9 @@ static int write_partial_msg_pages(struct ceph_connection *con)
void *base; void *base;
u32 crc; u32 crc;
u32 tmpcrc = le32_to_cpu(con->out_msg->footer.data_crc); u32 tmpcrc = le32_to_cpu(con->out_msg->footer.data_crc);
char *kaddr;
kaddr = kmap(page);
BUG_ON(kaddr == NULL); BUG_ON(kaddr == NULL);
base = kaddr + con->out_msg_pos.page_pos + bio_offset; base = kaddr + con->out_msg_pos.page_pos + bio_offset;
crc = crc32c(tmpcrc, base, len); crc = crc32c(tmpcrc, base, len);
......
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