[Patch v2 12/15] CIFS: Pass page offset for encrypting

From: Long Li
Date: Wed May 30 2018 - 15:50:13 EST


From: Long Li <longli@xxxxxxxxxxxxx>

Encryption function needs to read data starting page offset from input
buffer.

This doesn't affect decryption path since it allocates its own page
buffers.

Signed-off-by: Long Li <longli@xxxxxxxxxxxxx>
---
fs/cifs/smb2ops.c | 20 +++++++++++++-------
1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 1fa1c29..38d19b6 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -2189,9 +2189,10 @@ init_sg(struct smb_rqst *rqst, u8 *sign)
smb2_sg_set_buf(&sg[i], rqst->rq_iov[i].iov_base,
rqst->rq_iov[i].iov_len);
for (j = 0; i < sg_len - 1; i++, j++) {
- unsigned int len = (j < rqst->rq_npages - 1) ? rqst->rq_pagesz
- : rqst->rq_tailsz;
- sg_set_page(&sg[i], rqst->rq_pages[j], len, 0);
+ unsigned int len, offset;
+
+ rqst_page_get_length(rqst, j, &len, &offset);
+ sg_set_page(&sg[i], rqst->rq_pages[j], len, offset);
}
smb2_sg_set_buf(&sg[sg_len - 1], sign, SMB2_SIGNATURE_SIZE);
return sg;
@@ -2332,6 +2333,7 @@ smb3_init_transform_rq(struct TCP_Server_Info *server, struct smb_rqst *new_rq,
return rc;

new_rq->rq_pages = pages;
+ new_rq->rq_offset = old_rq->rq_offset;
new_rq->rq_npages = old_rq->rq_npages;
new_rq->rq_pagesz = old_rq->rq_pagesz;
new_rq->rq_tailsz = old_rq->rq_tailsz;
@@ -2363,10 +2365,14 @@ smb3_init_transform_rq(struct TCP_Server_Info *server, struct smb_rqst *new_rq,

/* copy pages form the old */
for (i = 0; i < npages; i++) {
- char *dst = kmap(new_rq->rq_pages[i]);
- char *src = kmap(old_rq->rq_pages[i]);
- unsigned int len = (i < npages - 1) ? new_rq->rq_pagesz :
- new_rq->rq_tailsz;
+ char *dst, *src;
+ unsigned int offset, len;
+
+ rqst_page_get_length(new_rq, i, &len, &offset);
+
+ dst = (char *) kmap(new_rq->rq_pages[i]) + offset;
+ src = (char *) kmap(old_rq->rq_pages[i]) + offset;
+
memcpy(dst, src, len);
kunmap(new_rq->rq_pages[i]);
kunmap(old_rq->rq_pages[i]);
--
2.7.4