From 1ef255e257173f4bc44317ef2076e7e0de688fdf Mon Sep 17 00:00:00 2001 From: Al Viro Date: Thu, 9 Jun 2022 10:28:36 -0400 Subject: iov_iter: advancing variants of iov_iter_get_pages{,_alloc}() Most of the users immediately follow successful iov_iter_get_pages() with advancing by the amount it had returned. Provide inline wrappers doing that, convert trivial open-coded uses of those. BTW, iov_iter_get_pages() never returns more than it had been asked to; such checks in cifs ought to be removed someday... Reviewed-by: Jeff Layton Signed-off-by: Al Viro --- net/core/datagram.c | 3 +-- net/core/skmsg.c | 3 +-- net/rds/message.c | 3 +-- net/tls/tls_sw.c | 4 +--- 4 files changed, 4 insertions(+), 9 deletions(-) (limited to 'net') diff --git a/net/core/datagram.c b/net/core/datagram.c index f3988ef8e9af..7255531f63ae 100644 --- a/net/core/datagram.c +++ b/net/core/datagram.c @@ -632,12 +632,11 @@ int __zerocopy_sg_from_iter(struct msghdr *msg, struct sock *sk, if (frag == MAX_SKB_FRAGS) return -EMSGSIZE; - copied = iov_iter_get_pages(from, pages, length, + copied = iov_iter_get_pages2(from, pages, length, MAX_SKB_FRAGS - frag, &start); if (copied < 0) return -EFAULT; - iov_iter_advance(from, copied); length -= copied; truesize = PAGE_ALIGN(copied + start); diff --git a/net/core/skmsg.c b/net/core/skmsg.c index 81627892bdd4..cf3c24c8610d 100644 --- a/net/core/skmsg.c +++ b/net/core/skmsg.c @@ -324,14 +324,13 @@ int sk_msg_zerocopy_from_iter(struct sock *sk, struct iov_iter *from, goto out; } - copied = iov_iter_get_pages(from, pages, bytes, maxpages, + copied = iov_iter_get_pages2(from, pages, bytes, maxpages, &offset); if (copied <= 0) { ret = -EFAULT; goto out; } - iov_iter_advance(from, copied); bytes -= copied; msg->sg.size += copied; diff --git a/net/rds/message.c b/net/rds/message.c index 799034e0f513..d74be4e3f3fa 100644 --- a/net/rds/message.c +++ b/net/rds/message.c @@ -391,7 +391,7 @@ static int rds_message_zcopy_from_user(struct rds_message *rm, struct iov_iter * size_t start; ssize_t copied; - copied = iov_iter_get_pages(from, &pages, PAGE_SIZE, + copied = iov_iter_get_pages2(from, &pages, PAGE_SIZE, 1, &start); if (copied < 0) { struct mmpin *mmp; @@ -405,7 +405,6 @@ static int rds_message_zcopy_from_user(struct rds_message *rm, struct iov_iter * goto err; } total_copied += copied; - iov_iter_advance(from, copied); length -= copied; sg_set_page(sg, pages, copied, start); rm->data.op_nents++; diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c index 17db8c8811fa..f76119f62f1b 100644 --- a/net/tls/tls_sw.c +++ b/net/tls/tls_sw.c @@ -1352,7 +1352,7 @@ static int tls_setup_from_iter(struct iov_iter *from, rc = -EFAULT; goto out; } - copied = iov_iter_get_pages(from, pages, + copied = iov_iter_get_pages2(from, pages, length, maxpages, &offset); if (copied <= 0) { @@ -1360,8 +1360,6 @@ static int tls_setup_from_iter(struct iov_iter *from, goto out; } - iov_iter_advance(from, copied); - length -= copied; size += copied; while (copied) { -- cgit v1.2.3-70-g09d2 From 7f02464739da05a51cadb997a00a301f734e9c87 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Fri, 10 Jun 2022 11:42:02 -0400 Subject: 9p: convert to advancing variant of iov_iter_get_pages_alloc() that one is somewhat clumsier than usual and needs serious testing. Signed-off-by: Al Viro --- net/9p/client.c | 39 +++++++++++++++++++++++---------------- net/9p/protocol.c | 3 +-- net/9p/trans_virtio.c | 3 ++- 3 files changed, 26 insertions(+), 19 deletions(-) (limited to 'net') diff --git a/net/9p/client.c b/net/9p/client.c index d403085b9ef5..cb4324211561 100644 --- a/net/9p/client.c +++ b/net/9p/client.c @@ -1491,7 +1491,7 @@ p9_client_read_once(struct p9_fid *fid, u64 offset, struct iov_iter *to, struct p9_client *clnt = fid->clnt; struct p9_req_t *req; int count = iov_iter_count(to); - int rsize, non_zc = 0; + int rsize, received, non_zc = 0; char *dataptr; *err = 0; @@ -1520,36 +1520,40 @@ p9_client_read_once(struct p9_fid *fid, u64 offset, struct iov_iter *to, } if (IS_ERR(req)) { *err = PTR_ERR(req); + if (!non_zc) + iov_iter_revert(to, count - iov_iter_count(to)); return 0; } *err = p9pdu_readf(&req->rc, clnt->proto_version, - "D", &count, &dataptr); + "D", &received, &dataptr); if (*err) { + if (!non_zc) + iov_iter_revert(to, count - iov_iter_count(to)); trace_9p_protocol_dump(clnt, &req->rc); p9_tag_remove(clnt, req); return 0; } - if (rsize < count) { - pr_err("bogus RREAD count (%d > %d)\n", count, rsize); - count = rsize; + if (rsize < received) { + pr_err("bogus RREAD count (%d > %d)\n", received, rsize); + received = rsize; } p9_debug(P9_DEBUG_9P, "<<< RREAD count %d\n", count); if (non_zc) { - int n = copy_to_iter(dataptr, count, to); + int n = copy_to_iter(dataptr, received, to); - if (n != count) { + if (n != received) { *err = -EFAULT; p9_tag_remove(clnt, req); return n; } } else { - iov_iter_advance(to, count); + iov_iter_revert(to, count - received - iov_iter_count(to)); } p9_tag_remove(clnt, req); - return count; + return received; } EXPORT_SYMBOL(p9_client_read_once); @@ -1567,6 +1571,7 @@ p9_client_write(struct p9_fid *fid, u64 offset, struct iov_iter *from, int *err) while (iov_iter_count(from)) { int count = iov_iter_count(from); int rsize = fid->iounit; + int written; if (!rsize || rsize > clnt->msize - P9_IOHDRSZ) rsize = clnt->msize - P9_IOHDRSZ; @@ -1584,27 +1589,29 @@ p9_client_write(struct p9_fid *fid, u64 offset, struct iov_iter *from, int *err) offset, rsize, from); } if (IS_ERR(req)) { + iov_iter_revert(from, count - iov_iter_count(from)); *err = PTR_ERR(req); break; } - *err = p9pdu_readf(&req->rc, clnt->proto_version, "d", &count); + *err = p9pdu_readf(&req->rc, clnt->proto_version, "d", &written); if (*err) { + iov_iter_revert(from, count - iov_iter_count(from)); trace_9p_protocol_dump(clnt, &req->rc); p9_tag_remove(clnt, req); break; } - if (rsize < count) { - pr_err("bogus RWRITE count (%d > %d)\n", count, rsize); - count = rsize; + if (rsize < written) { + pr_err("bogus RWRITE count (%d > %d)\n", written, rsize); + written = rsize; } p9_debug(P9_DEBUG_9P, "<<< RWRITE count %d\n", count); p9_tag_remove(clnt, req); - iov_iter_advance(from, count); - total += count; - offset += count; + iov_iter_revert(from, count - written - iov_iter_count(from)); + total += written; + offset += written; } return total; } diff --git a/net/9p/protocol.c b/net/9p/protocol.c index 3754c33e2974..83694c631989 100644 --- a/net/9p/protocol.c +++ b/net/9p/protocol.c @@ -63,9 +63,8 @@ static size_t pdu_write_u(struct p9_fcall *pdu, struct iov_iter *from, size_t size) { size_t len = min(pdu->capacity - pdu->size, size); - struct iov_iter i = *from; - if (!copy_from_iter_full(&pdu->sdata[pdu->size], len, &i)) + if (!copy_from_iter_full(&pdu->sdata[pdu->size], len, from)) len = 0; pdu->size += len; diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c index 2a210c2f8e40..1977d33475fe 100644 --- a/net/9p/trans_virtio.c +++ b/net/9p/trans_virtio.c @@ -331,7 +331,7 @@ static int p9_get_mapped_pages(struct virtio_chan *chan, if (err == -ERESTARTSYS) return err; } - n = iov_iter_get_pages_alloc(data, pages, count, offs); + n = iov_iter_get_pages_alloc2(data, pages, count, offs); if (n < 0) return n; *need_drop = 1; @@ -373,6 +373,7 @@ static int p9_get_mapped_pages(struct virtio_chan *chan, (*pages)[index] = kmap_to_page(p); p += PAGE_SIZE; } + iov_iter_advance(data, len); return len; } } -- cgit v1.2.3-70-g09d2