From 12bdcf333fe13ece2a487a699b1a0f4c5dbb594b Mon Sep 17 00:00:00 2001 From: David Howells Date: Sat, 20 Oct 2018 00:57:56 +0100 Subject: afs: Set up the iov_iter before calling afs_extract_data() afs_extract_data sets up a temporary iov_iter and passes it to AF_RXRPC each time it is called to describe the remaining buffer to be filled. Instead: (1) Put an iterator in the afs_call struct. (2) Set the iterator for each marshalling stage to load data into the appropriate places. A number of convenience functions are provided to this end (eg. afs_extract_to_buf()). This iterator is then passed to afs_extract_data(). (3) Use the new ITER_DISCARD iterator to discard any excess data provided by FetchData. Signed-off-by: David Howells --- fs/afs/fsclient.c | 282 ++++++++++++++++++------------------------------------ 1 file changed, 95 insertions(+), 187 deletions(-) (limited to 'fs/afs/fsclient.c') diff --git a/fs/afs/fsclient.c b/fs/afs/fsclient.c index d9a5815945dc..fe2e9e39b388 100644 --- a/fs/afs/fsclient.c +++ b/fs/afs/fsclient.c @@ -20,12 +20,6 @@ static const struct afs_fid afs_zero_fid; -/* - * We need somewhere to discard into in case the server helpfully returns more - * than we asked for in FS.FetchData{,64}. - */ -static u8 afs_discard_buffer[64]; - static inline void afs_use_fs_server(struct afs_call *call, struct afs_cb_interest *cbi) { call->cbi = afs_get_cb_interest(cbi); @@ -469,114 +463,93 @@ static int afs_deliver_fs_fetch_data(struct afs_call *call) struct afs_read *req = call->reply[2]; const __be32 *bp; unsigned int size; - void *buffer; int ret; - _enter("{%u,%zu/%u;%llu/%llu}", - call->unmarshall, call->offset, call->count, - req->remain, req->actual_len); + _enter("{%u,%zu/%llu}", + call->unmarshall, iov_iter_count(&call->iter), req->actual_len); switch (call->unmarshall) { case 0: req->actual_len = 0; - call->offset = 0; + req->index = 0; + req->offset = req->pos & (PAGE_SIZE - 1); call->unmarshall++; - if (call->operation_ID != FSFETCHDATA64) { - call->unmarshall++; - goto no_msw; + if (call->operation_ID == FSFETCHDATA64) { + afs_extract_to_tmp64(call); + } else { + call->tmp_u = htonl(0); + afs_extract_to_tmp(call); } - /* extract the upper part of the returned data length of an - * FSFETCHDATA64 op (which should always be 0 using this - * client) */ - case 1: - _debug("extract data length (MSW)"); - ret = afs_extract_data(call, &call->tmp, 4, true); - if (ret < 0) - return ret; - - req->actual_len = ntohl(call->tmp); - req->actual_len <<= 32; - call->offset = 0; - call->unmarshall++; - - no_msw: /* extract the returned data length */ - case 2: + case 1: _debug("extract data length"); - ret = afs_extract_data(call, &call->tmp, 4, true); + ret = afs_extract_data(call, true); if (ret < 0) return ret; - req->actual_len |= ntohl(call->tmp); + req->actual_len = be64_to_cpu(call->tmp64); _debug("DATA length: %llu", req->actual_len); - - req->remain = req->actual_len; - call->offset = req->pos & (PAGE_SIZE - 1); - req->index = 0; - if (req->actual_len == 0) + req->remain = min(req->len, req->actual_len); + if (req->remain == 0) goto no_more_data; + call->unmarshall++; begin_page: ASSERTCMP(req->index, <, req->nr_pages); - if (req->remain > PAGE_SIZE - call->offset) - size = PAGE_SIZE - call->offset; + if (req->remain > PAGE_SIZE - req->offset) + size = PAGE_SIZE - req->offset; else size = req->remain; - call->count = call->offset + size; - ASSERTCMP(call->count, <=, PAGE_SIZE); - req->remain -= size; + call->bvec[0].bv_len = size; + call->bvec[0].bv_offset = req->offset; + call->bvec[0].bv_page = req->pages[req->index]; + iov_iter_bvec(&call->iter, READ, call->bvec, 1, size); + ASSERTCMP(size, <=, PAGE_SIZE); /* extract the returned data */ - case 3: - _debug("extract data %llu/%llu %zu/%u", - req->remain, req->actual_len, call->offset, call->count); + case 2: + _debug("extract data %zu/%llu", + iov_iter_count(&call->iter), req->remain); - buffer = kmap(req->pages[req->index]); - ret = afs_extract_data(call, buffer, call->count, true); - kunmap(req->pages[req->index]); + ret = afs_extract_data(call, true); if (ret < 0) return ret; - if (call->offset == PAGE_SIZE) { + req->remain -= call->bvec[0].bv_len; + req->offset += call->bvec[0].bv_len; + ASSERTCMP(req->offset, <=, PAGE_SIZE); + if (req->offset == PAGE_SIZE) { + req->offset = 0; if (req->page_done) req->page_done(call, req); req->index++; - if (req->remain > 0) { - call->offset = 0; - if (req->index >= req->nr_pages) { - call->unmarshall = 4; - goto begin_discard; - } + if (req->remain > 0) goto begin_page; - } } - goto no_more_data; + + ASSERTCMP(req->remain, ==, 0); + if (req->actual_len <= req->len) + goto no_more_data; /* Discard any excess data the server gave us */ - begin_discard: - case 4: - size = min_t(loff_t, sizeof(afs_discard_buffer), req->remain); - call->count = size; - _debug("extract discard %llu/%llu %zu/%u", - req->remain, req->actual_len, call->offset, call->count); - - call->offset = 0; - ret = afs_extract_data(call, afs_discard_buffer, call->count, true); - req->remain -= call->offset; + iov_iter_discard(&call->iter, READ, req->actual_len - req->len); + call->unmarshall = 3; + case 3: + _debug("extract discard %zu/%llu", + iov_iter_count(&call->iter), req->actual_len - req->len); + + ret = afs_extract_data(call, true); if (ret < 0) return ret; - if (req->remain > 0) - goto begin_discard; no_more_data: - call->offset = 0; - call->unmarshall = 5; + call->unmarshall = 4; + afs_extract_to_buf(call, (21 + 3 + 6) * 4); /* extract the metadata */ - case 5: - ret = afs_extract_data(call, call->buffer, - (21 + 3 + 6) * 4, false); + case 4: + ret = afs_extract_data(call, false); if (ret < 0) return ret; @@ -589,20 +562,19 @@ static int afs_deliver_fs_fetch_data(struct afs_call *call) if (call->reply[1]) xdr_decode_AFSVolSync(&bp, call->reply[1]); - call->offset = 0; call->unmarshall++; - case 6: + case 5: break; } for (; req->index < req->nr_pages; req->index++) { - if (call->count < PAGE_SIZE) + if (req->offset < PAGE_SIZE) zero_user_segment(req->pages[req->index], - call->count, PAGE_SIZE); + req->offset, PAGE_SIZE); if (req->page_done) req->page_done(call, req); - call->count = 0; + req->offset = 0; } _leave(" = 0 [done]"); @@ -1598,31 +1570,31 @@ static int afs_deliver_fs_get_volume_status(struct afs_call *call) { const __be32 *bp; char *p; + u32 size; int ret; _enter("{%u}", call->unmarshall); switch (call->unmarshall) { case 0: - call->offset = 0; call->unmarshall++; + afs_extract_to_buf(call, 12 * 4); /* extract the returned status record */ case 1: _debug("extract status"); - ret = afs_extract_data(call, call->buffer, - 12 * 4, true); + ret = afs_extract_data(call, true); if (ret < 0) return ret; bp = call->buffer; xdr_decode_AFSFetchVolumeStatus(&bp, call->reply[1]); - call->offset = 0; call->unmarshall++; + afs_extract_to_tmp(call); /* extract the volume name length */ case 2: - ret = afs_extract_data(call, &call->tmp, 4, true); + ret = afs_extract_data(call, true); if (ret < 0) return ret; @@ -1631,46 +1603,26 @@ static int afs_deliver_fs_get_volume_status(struct afs_call *call) if (call->count >= AFSNAMEMAX) return afs_protocol_error(call, -EBADMSG, afs_eproto_volname_len); - call->offset = 0; + size = (call->count + 3) & ~3; /* It's padded */ + afs_extract_begin(call, call->reply[2], size); call->unmarshall++; /* extract the volume name */ case 3: _debug("extract volname"); - if (call->count > 0) { - ret = afs_extract_data(call, call->reply[2], - call->count, true); - if (ret < 0) - return ret; - } + ret = afs_extract_data(call, true); + if (ret < 0) + return ret; p = call->reply[2]; p[call->count] = 0; _debug("volname '%s'", p); - - call->offset = 0; + afs_extract_to_tmp(call); call->unmarshall++; - /* extract the volume name padding */ - if ((call->count & 3) == 0) { - call->unmarshall++; - goto no_volname_padding; - } - call->count = 4 - (call->count & 3); - - case 4: - ret = afs_extract_data(call, call->buffer, - call->count, true); - if (ret < 0) - return ret; - - call->offset = 0; - call->unmarshall++; - no_volname_padding: - /* extract the offline message length */ - case 5: - ret = afs_extract_data(call, &call->tmp, 4, true); + case 4: + ret = afs_extract_data(call, true); if (ret < 0) return ret; @@ -1679,46 +1631,27 @@ static int afs_deliver_fs_get_volume_status(struct afs_call *call) if (call->count >= AFSNAMEMAX) return afs_protocol_error(call, -EBADMSG, afs_eproto_offline_msg_len); - call->offset = 0; + size = (call->count + 3) & ~3; /* It's padded */ + afs_extract_begin(call, call->reply[2], size); call->unmarshall++; /* extract the offline message */ - case 6: + case 5: _debug("extract offline"); - if (call->count > 0) { - ret = afs_extract_data(call, call->reply[2], - call->count, true); - if (ret < 0) - return ret; - } + ret = afs_extract_data(call, true); + if (ret < 0) + return ret; p = call->reply[2]; p[call->count] = 0; _debug("offline '%s'", p); - call->offset = 0; + afs_extract_to_tmp(call); call->unmarshall++; - /* extract the offline message padding */ - if ((call->count & 3) == 0) { - call->unmarshall++; - goto no_offline_padding; - } - call->count = 4 - (call->count & 3); - - case 7: - ret = afs_extract_data(call, call->buffer, - call->count, true); - if (ret < 0) - return ret; - - call->offset = 0; - call->unmarshall++; - no_offline_padding: - /* extract the message of the day length */ - case 8: - ret = afs_extract_data(call, &call->tmp, 4, true); + case 6: + ret = afs_extract_data(call, true); if (ret < 0) return ret; @@ -1727,38 +1660,24 @@ static int afs_deliver_fs_get_volume_status(struct afs_call *call) if (call->count >= AFSNAMEMAX) return afs_protocol_error(call, -EBADMSG, afs_eproto_motd_len); - call->offset = 0; + size = (call->count + 3) & ~3; /* It's padded */ + afs_extract_begin(call, call->reply[2], size); call->unmarshall++; /* extract the message of the day */ - case 9: + case 7: _debug("extract motd"); - if (call->count > 0) { - ret = afs_extract_data(call, call->reply[2], - call->count, true); - if (ret < 0) - return ret; - } + ret = afs_extract_data(call, false); + if (ret < 0) + return ret; p = call->reply[2]; p[call->count] = 0; _debug("motd '%s'", p); - call->offset = 0; call->unmarshall++; - /* extract the message of the day padding */ - call->count = (4 - (call->count & 3)) & 3; - - case 10: - ret = afs_extract_data(call, call->buffer, - call->count, false); - if (ret < 0) - return ret; - - call->offset = 0; - call->unmarshall++; - case 11: + case 8: break; } @@ -2024,19 +1943,16 @@ static int afs_deliver_fs_get_capabilities(struct afs_call *call) u32 count; int ret; - _enter("{%u,%zu/%u}", call->unmarshall, call->offset, call->count); + _enter("{%u,%zu}", call->unmarshall, iov_iter_count(&call->iter)); -again: switch (call->unmarshall) { case 0: - call->offset = 0; + afs_extract_to_tmp(call); call->unmarshall++; /* Extract the capabilities word count */ case 1: - ret = afs_extract_data(call, &call->tmp, - 1 * sizeof(__be32), - true); + ret = afs_extract_data(call, true); if (ret < 0) return ret; @@ -2044,24 +1960,17 @@ again: call->count = count; call->count2 = count; - call->offset = 0; + iov_iter_discard(&call->iter, READ, count * sizeof(__be32)); call->unmarshall++; /* Extract capabilities words */ case 2: - count = min(call->count, 16U); - ret = afs_extract_data(call, call->buffer, - count * sizeof(__be32), - call->count > 16); + ret = afs_extract_data(call, false); if (ret < 0) return ret; /* TODO: Examine capabilities */ - call->count -= count; - if (call->count > 0) - goto again; - call->offset = 0; call->unmarshall++; break; } @@ -2215,13 +2124,13 @@ static int afs_deliver_fs_inline_bulk_status(struct afs_call *call) switch (call->unmarshall) { case 0: - call->offset = 0; + afs_extract_to_tmp(call); call->unmarshall++; /* Extract the file status count and array in two steps */ case 1: _debug("extract status count"); - ret = afs_extract_data(call, &call->tmp, 4, true); + ret = afs_extract_data(call, true); if (ret < 0) return ret; @@ -2234,11 +2143,11 @@ static int afs_deliver_fs_inline_bulk_status(struct afs_call *call) call->count = 0; call->unmarshall++; more_counts: - call->offset = 0; + afs_extract_to_buf(call, 21 * sizeof(__be32)); case 2: _debug("extract status array %u", call->count); - ret = afs_extract_data(call, call->buffer, 21 * 4, true); + ret = afs_extract_data(call, true); if (ret < 0) return ret; @@ -2256,12 +2165,12 @@ static int afs_deliver_fs_inline_bulk_status(struct afs_call *call) call->count = 0; call->unmarshall++; - call->offset = 0; + afs_extract_to_tmp(call); /* Extract the callback count and array in two steps */ case 3: _debug("extract CB count"); - ret = afs_extract_data(call, &call->tmp, 4, true); + ret = afs_extract_data(call, true); if (ret < 0) return ret; @@ -2273,11 +2182,11 @@ static int afs_deliver_fs_inline_bulk_status(struct afs_call *call) call->count = 0; call->unmarshall++; more_cbs: - call->offset = 0; + afs_extract_to_buf(call, 3 * sizeof(__be32)); case 4: _debug("extract CB array"); - ret = afs_extract_data(call, call->buffer, 3 * 4, true); + ret = afs_extract_data(call, true); if (ret < 0) return ret; @@ -2294,11 +2203,11 @@ static int afs_deliver_fs_inline_bulk_status(struct afs_call *call) if (call->count < call->count2) goto more_cbs; - call->offset = 0; + afs_extract_to_buf(call, 6 * sizeof(__be32)); call->unmarshall++; case 5: - ret = afs_extract_data(call, call->buffer, 6 * 4, false); + ret = afs_extract_data(call, false); if (ret < 0) return ret; @@ -2306,7 +2215,6 @@ static int afs_deliver_fs_inline_bulk_status(struct afs_call *call) if (call->reply[3]) xdr_decode_AFSVolSync(&bp, call->reply[3]); - call->offset = 0; call->unmarshall++; case 6: -- cgit v1.2.3