Add code that allows smb_send_rqst to send an array of pages after the initial kvec array has been sent. For now, we simply kmap the page array and send it using the standard smb_send_kvec function. Eventually, we may want to convert this code to use kernel_sendpage under the hood and avoid the kmap altogether for the page data.
Signed-off-by: Jeff Layton <[email protected]> --- fs/cifs/transport.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 54 insertions(+), 2 deletions(-) diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c index af56e91..006c3fb 100644 --- a/fs/cifs/transport.c +++ b/fs/cifs/transport.c @@ -28,6 +28,7 @@ #include <linux/delay.h> #include <linux/freezer.h> #include <linux/tcp.h> +#include <linux/highmem.h> #include <asm/uaccess.h> #include <asm/processor.h> #include <linux/mempool.h> @@ -241,6 +242,38 @@ smb_send_kvec(struct TCP_Server_Info *server, struct kvec *iov, size_t n_vec, return rc; } +/** + * rqst_page_to_kvec - Turn a slot in the smb_rqst page array into a kvec + * @rqst: pointer to smb_rqst + * @idx: index into the array of the page + * @iov: pointer to struct kvec that will hold the result + * + * Helper function to convert a slot in the rqst->rq_pages array into a kvec. + * The page will be kmapped and the address placed into iov_base. The length + * will then be adjusted according to the ptailoff. + */ +static void +cifs_rqst_page_to_kvec(struct smb_rqst *rqst, unsigned int idx, + struct kvec *iov) +{ + /* + * FIXME: We could avoid this kmap altogether if we used + * kernel_sendpage instead of kernel_sendmsg. That will only + * work if signing is disabled though as sendpage inlines the + * page directly into the fraglist. If userspace modifies the + * page after we calculate the signature, then the server will + * reject it and may break the connection. kernel_sendmsg does + * an extra copy of the data and avoids that issue. + */ + iov->iov_base = kmap(rqst->rq_pages[idx]); + + /* if last page, don't send beyond this offset into page */ + if (idx == (rqst->rq_npages - 1)) + iov->iov_len = rqst->rq_tailsz; + else + iov->iov_len = rqst->rq_pagesz; +} + static int smb_send_rqst(struct TCP_Server_Info *server, struct smb_rqst *rqst) { @@ -248,7 +281,8 @@ smb_send_rqst(struct TCP_Server_Info *server, struct smb_rqst *rqst) struct kvec *iov = rqst->rq_iov; int n_vec = rqst->rq_nvec; unsigned int smb_buf_length = get_rfc1002_length(iov[0].iov_base); - size_t total_len; + unsigned int i; + size_t total_len = 0, sent; struct socket *ssocket = server->ssocket; int val = 1; @@ -259,8 +293,26 @@ smb_send_rqst(struct TCP_Server_Info *server, struct smb_rqst *rqst) kernel_setsockopt(ssocket, SOL_TCP, TCP_CORK, (char *)&val, sizeof(val)); - rc = smb_send_kvec(server, iov, n_vec, &total_len); + rc = smb_send_kvec(server, iov, n_vec, &sent); + if (rc < 0) + goto uncork; + + total_len += sent; + + /* now walk the page array and send each page in it */ + for (i = 0; i < rqst->rq_npages; i++) { + struct kvec p_iov; + + cifs_rqst_page_to_kvec(rqst, i, &p_iov); + rc = smb_send_kvec(server, &p_iov, 1, &sent); + kunmap(rqst->rq_pages[i]); + if (rc < 0) + break; + + total_len += sent; + } +uncork: /* uncork it */ val = 0; kernel_setsockopt(ssocket, SOL_TCP, TCP_CORK, -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-cifs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
