Commit bc925c12 authored by Paulo Alcantara's avatar Paulo Alcantara Committed by Steve French
Browse files

smb: client: improve compound padding in encryption 



After commit f7f291e1 ("cifs: fix oops during encryption"), the
encryption layer can handle vmalloc'd buffers as well as kmalloc'd
buffers, so there is no need to inefficiently squash request iovs
into a single one to handle padding in compound requests.

Cc: David Howells <dhowells@redhat.com>
Signed-off-by: default avatarPaulo Alcantara (Red Hat) <pc@manguebit.com>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent 9ed9d83a

fs/smb/client/cifsglob.h

+2 −2
Original line number Diff line number Diff line
@@ -2230,7 +2230,7 @@ static inline int cifs_get_num_sgs(const struct smb_rqst *rqst, 
			struct kvec *iov = &rqst[i].rq_iov[j];



			addr = (unsigned long)iov->iov_base + skip;

			if (unlikely(is_vmalloc_addr((void *)addr))) {

			if (is_vmalloc_or_module_addr((void *)addr)) {

				len = iov->iov_len - skip;

				nents += DIV_ROUND_UP(offset_in_page(addr) + len,

						      PAGE_SIZE);
@@ -2257,7 +2257,7 @@ static inline void cifs_sg_set_buf(struct sg_table *sgtable, 
	unsigned int off = offset_in_page(addr);



	addr &= PAGE_MASK;

	if (unlikely(is_vmalloc_addr((void *)addr))) {

	if (is_vmalloc_or_module_addr((void *)addr)) {

		do {

			unsigned int len = min_t(unsigned int, buflen, PAGE_SIZE - off);

fs/smb/client/smb2ops.c

+3 −34
Original line number Diff line number Diff line
@@ -2606,7 +2606,7 @@ smb2_set_next_command(struct cifs_tcon *tcon, struct smb_rqst *rqst) 
	struct cifs_ses *ses = tcon->ses;

	struct TCP_Server_Info *server = ses->server;

	unsigned long len = smb_rqst_len(server, rqst);

	int i, num_padding;

	int num_padding;



	shdr = (struct smb2_hdr *)(rqst->rq_iov[0].iov_base);

	if (shdr == NULL) {
@@ -2615,44 +2615,13 @@ smb2_set_next_command(struct cifs_tcon *tcon, struct smb_rqst *rqst) 
	}



	/* SMB headers in a compound are 8 byte aligned. */



	/* No padding needed */

	if (!(len & 7))

		goto finished;



	if (!IS_ALIGNED(len, 8)) {

		num_padding = 8 - (len & 7);

	if (!smb3_encryption_required(tcon)) {

		/*

		 * If we do not have encryption then we can just add an extra

		 * iov for the padding.

		 */

		rqst->rq_iov[rqst->rq_nvec].iov_base = smb2_padding;

		rqst->rq_iov[rqst->rq_nvec].iov_len = num_padding;

		rqst->rq_nvec++;

		len += num_padding;

	} else {

		/*

		 * We can not add a small padding iov for the encryption case

		 * because the encryption framework can not handle the padding

		 * iovs.

		 * We have to flatten this into a single buffer and add

		 * the padding to it.

		 */

		for (i = 1; i < rqst->rq_nvec; i++) {

			memcpy(rqst->rq_iov[0].iov_base +

			       rqst->rq_iov[0].iov_len,

			       rqst->rq_iov[i].iov_base,

			       rqst->rq_iov[i].iov_len);

			rqst->rq_iov[0].iov_len += rqst->rq_iov[i].iov_len;

		}

		memset(rqst->rq_iov[0].iov_base + rqst->rq_iov[0].iov_len,

		       0, num_padding);

		rqst->rq_iov[0].iov_len += num_padding;

		len += num_padding;

		rqst->rq_nvec = 1;

	}



 finished:

	shdr->NextCommand = cpu_to_le32(len);

}

fs/smb/client/transport.c

+13 −27
Original line number Diff line number Diff line
@@ -418,19 +418,16 @@ __smb_send_rqst(struct TCP_Server_Info *server, int num_rqst, 
	return rc;

}



struct send_req_vars {

	struct smb2_transform_hdr tr_hdr;

	struct smb_rqst rqst[MAX_COMPOUND];

	struct kvec iov;

};



static int

smb_send_rqst(struct TCP_Server_Info *server, int num_rqst,

	      struct smb_rqst *rqst, int flags)

{

	struct send_req_vars *vars;

	struct smb_rqst *cur_rqst;

	struct kvec *iov;

	struct smb2_transform_hdr tr_hdr;

	struct smb_rqst new_rqst[MAX_COMPOUND] = {};

	struct kvec iov = {

		.iov_base = &tr_hdr,

		.iov_len = sizeof(tr_hdr),

	};

	int rc;



	if (flags & CIFS_COMPRESS_REQ)
@@ -447,26 +444,15 @@ smb_send_rqst(struct TCP_Server_Info *server, int num_rqst, 
		return -EIO;

	}



	vars = kzalloc(sizeof(*vars), GFP_NOFS);

	if (!vars)

		return -ENOMEM;

	cur_rqst = vars->rqst;

	iov = &vars->iov;



	iov->iov_base = &vars->tr_hdr;

	iov->iov_len = sizeof(vars->tr_hdr);

	cur_rqst[0].rq_iov = iov;

	cur_rqst[0].rq_nvec = 1;

	new_rqst[0].rq_iov = &iov;

	new_rqst[0].rq_nvec = 1;



	rc = server->ops->init_transform_rq(server, num_rqst + 1,

					    &cur_rqst[0], rqst);

	if (rc)

		goto out;



	rc = __smb_send_rqst(server, num_rqst + 1, &cur_rqst[0]);

	smb3_free_compound_rqst(num_rqst, &cur_rqst[1]);

out:

	kfree(vars);

					    new_rqst, rqst);

	if (!rc) {

		rc = __smb_send_rqst(server, num_rqst + 1, new_rqst);

		smb3_free_compound_rqst(num_rqst, &new_rqst[1]);

	}

	return rc;

}