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/vlclient.c | 104 ++++++++++++++++++++++++------------------------------ 1 file changed, 46 insertions(+), 58 deletions(-) (limited to 'fs/afs/vlclient.c') diff --git a/fs/afs/vlclient.c b/fs/afs/vlclient.c index d0f95c4ab05e..e18c51742daa 100644 --- a/fs/afs/vlclient.c +++ b/fs/afs/vlclient.c @@ -187,19 +187,18 @@ static int afs_deliver_vl_get_addrs_u(struct afs_call *call) u32 uniquifier, nentries, count; int i, ret; - _enter("{%u,%zu/%u}", call->unmarshall, call->offset, call->count); + _enter("{%u,%zu/%u}", + call->unmarshall, iov_iter_count(call->_iter), call->count); -again: switch (call->unmarshall) { case 0: - call->offset = 0; + afs_extract_to_buf(call, + sizeof(struct afs_uuid__xdr) + 3 * sizeof(__be32)); call->unmarshall++; /* Extract the returned uuid, uniquifier, nentries and blkaddrs size */ case 1: - ret = afs_extract_data(call, call->buffer, - sizeof(struct afs_uuid__xdr) + 3 * sizeof(__be32), - true); + ret = afs_extract_data(call, true); if (ret < 0) return ret; @@ -216,28 +215,28 @@ again: call->reply[0] = alist; call->count = count; call->count2 = nentries; - call->offset = 0; call->unmarshall++; + more_entries: + count = min(call->count, 4U); + afs_extract_to_buf(call, count * sizeof(__be32)); + /* Extract entries */ case 2: - count = min(call->count, 4U); - ret = afs_extract_data(call, call->buffer, - count * sizeof(__be32), - call->count > 4); + ret = afs_extract_data(call, call->count > 4); if (ret < 0) return ret; alist = call->reply[0]; bp = call->buffer; + count = min(call->count, 4U); for (i = 0; i < count; i++) if (alist->nr_addrs < call->count2) afs_merge_fs_addr4(alist, *bp++, AFS_FS_PORT); call->count -= count; if (call->count > 0) - goto again; - call->offset = 0; + goto more_entries; call->unmarshall++; break; } @@ -318,44 +317,35 @@ static int afs_deliver_vl_get_capabilities(struct afs_call *call) u32 count; int ret; - _enter("{%u,%zu/%u}", call->unmarshall, call->offset, call->count); + _enter("{%u,%zu/%u}", + call->unmarshall, iov_iter_count(call->_iter), call->count); -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; count = ntohl(call->tmp); - call->count = count; call->count2 = count; - call->offset = 0; + call->unmarshall++; + afs_extract_discard(call, count * sizeof(__be32)); /* 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; } @@ -426,22 +416,19 @@ static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call) u32 uniquifier, size; int ret; - _enter("{%u,%zu/%u,%u}", call->unmarshall, call->offset, call->count, call->count2); + _enter("{%u,%zu,%u}", + call->unmarshall, iov_iter_count(call->_iter), call->count2); -again: switch (call->unmarshall) { case 0: - call->offset = 0; + afs_extract_to_buf(call, sizeof(uuid_t) + 3 * sizeof(__be32)); call->unmarshall = 1; /* Extract the returned uuid, uniquifier, fsEndpoints count and * either the first fsEndpoint type or the volEndpoints * count if there are no fsEndpoints. */ case 1: - ret = afs_extract_data(call, call->buffer, - sizeof(uuid_t) + - 3 * sizeof(__be32), - true); + ret = afs_extract_data(call, true); if (ret < 0) return ret; @@ -459,15 +446,11 @@ again: return -ENOMEM; alist->version = uniquifier; call->reply[0] = alist; - call->offset = 0; if (call->count == 0) goto extract_volendpoints; - call->unmarshall = 2; - - /* Extract fsEndpoints[] entries */ - case 2: + next_fsendpoint: switch (call->count2) { case YFS_ENDPOINT_IPV4: size = sizeof(__be32) * (1 + 1 + 1); @@ -481,7 +464,12 @@ again: } size += sizeof(__be32); - ret = afs_extract_data(call, call->buffer, size, true); + afs_extract_to_buf(call, size); + call->unmarshall = 2; + + /* Extract fsEndpoints[] entries */ + case 2: + ret = afs_extract_data(call, true); if (ret < 0) return ret; @@ -512,10 +500,9 @@ again: */ call->count2 = ntohl(*bp++); - call->offset = 0; call->count--; if (call->count > 0) - goto again; + goto next_fsendpoint; extract_volendpoints: /* Extract the list of volEndpoints. */ @@ -526,6 +513,7 @@ again: return afs_protocol_error(call, -EBADMSG, afs_eproto_yvl_vlendpt_type); + afs_extract_to_buf(call, 1 * sizeof(__be32)); call->unmarshall = 3; /* Extract the type of volEndpoints[0]. Normally we would @@ -533,17 +521,14 @@ again: * data of the current one, but this is the first... */ case 3: - ret = afs_extract_data(call, call->buffer, sizeof(__be32), true); + ret = afs_extract_data(call, true); if (ret < 0) return ret; bp = call->buffer; - call->count2 = ntohl(*bp++); - call->offset = 0; - call->unmarshall = 4; - /* Extract volEndpoints[] entries */ - case 4: + next_volendpoint: + call->count2 = ntohl(*bp++); switch (call->count2) { case YFS_ENDPOINT_IPV4: size = sizeof(__be32) * (1 + 1 + 1); @@ -557,8 +542,13 @@ again: } if (call->count > 1) - size += sizeof(__be32); - ret = afs_extract_data(call, call->buffer, size, true); + size += sizeof(__be32); /* Get next type too */ + afs_extract_to_buf(call, size); + call->unmarshall = 4; + + /* Extract volEndpoints[] entries */ + case 4: + ret = afs_extract_data(call, true); if (ret < 0) return ret; @@ -584,19 +574,17 @@ again: /* Got either the type of the next entry or the count of * volEndpoints if no more fsEndpoints. */ - call->offset = 0; call->count--; - if (call->count > 0) { - call->count2 = ntohl(*bp++); - goto again; - } + if (call->count > 0) + goto next_volendpoint; end: + afs_extract_discard(call, 0); call->unmarshall = 5; /* Done */ case 5: - ret = afs_extract_data(call, call->buffer, 0, false); + ret = afs_extract_data(call, false); if (ret < 0) return ret; call->unmarshall = 6; -- cgit v1.2.3