From c06a0f2dff704d9f734ff0d3d4812ccfc46ed8d0 Mon Sep 17 00:00:00 2001 From: Long Li Date: Wed, 30 May 2018 12:47:57 -0700 Subject: [PATCH] CIFS: Calculate the correct request length based on page offset and tail size It's possible that the page offset is non-zero in the pages in a request, change the function to calculate the correct data buffer length. Signed-off-by: Long Li Signed-off-by: Steve French --- fs/cifs/transport.c | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-) diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c index e7254e386b79..d6cff1e5afc6 100644 --- a/fs/cifs/transport.c +++ b/fs/cifs/transport.c @@ -212,10 +212,24 @@ rqst_len(struct smb_rqst *rqst) for (i = 0; i < rqst->rq_nvec; i++) buflen += iov[i].iov_len; - /* add in the page array if there is one */ + /* + * Add in the page array if there is one. The caller needs to make + * sure rq_offset and rq_tailsz are set correctly. If a buffer of + * multiple pages ends at page boundary, rq_tailsz needs to be set to + * PAGE_SIZE. + */ if (rqst->rq_npages) { - buflen += rqst->rq_pagesz * (rqst->rq_npages - 1); - buflen += rqst->rq_tailsz; + if (rqst->rq_npages == 1) + buflen += rqst->rq_tailsz; + else { + /* + * If there is more than one page, calculate the + * buffer length based on rq_offset and rq_tailsz + */ + buflen += rqst->rq_pagesz * (rqst->rq_npages - 1) - + rqst->rq_offset; + buflen += rqst->rq_tailsz; + } } return buflen;