From c450846461f88b8888d6f5c2a2aa63ab64864978 Mon Sep 17 00:00:00 2001 From: David Howells Date: Thu, 6 Feb 2020 14:22:28 +0000 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_XARRAY iterator when reading data to load directly into the inode's pages without needing to create a list of them. This will allow O_DIRECT calls to be supported in future patches. Signed-off-by: David Howells Tested-By: Marc Dionne cc: linux-afs@lists.infradead.org cc: linux-cachefs@redhat.com cc: linux-fsdevel@vger.kernel.org Link: https://lore.kernel.org/r/152898380012.11616.12094591785228251717.stgit@warthog.procyon.org.uk/ Link: https://lore.kernel.org/r/153685394431.14766.3178466345696987059.stgit@warthog.procyon.org.uk/ Link: https://lore.kernel.org/r/153999787395.866.11218209749223643998.stgit@warthog.procyon.org.uk/ Link: https://lore.kernel.org/r/154033911195.12041.3882700371848894587.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/158861250059.340223.1248231474865140653.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/159465827399.1377938.11181327349704960046.stgit@warthog.procyon.org.uk/ Link: https://lore.kernel.org/r/160588533776.3465195.3612752083351956948.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/161118151238.1232039.17015723405750601161.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/161161047240.2537118.14721975104810564022.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/161340410333.1303470.16260122230371140878.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/161539554187.286939.15305559004905459852.stgit@warthog.procyon.org.uk/ # v4 Link: https://lore.kernel.org/r/161653810525.2770958.4630666029125411789.stgit@warthog.procyon.org.uk/ # v5 Link: https://lore.kernel.org/r/161789093719.6155.7877160739235087723.stgit@warthog.procyon.org.uk/ # v6 --- fs/afs/yfsclient.c | 54 ++++++++++++++---------------------------------------- 1 file changed, 14 insertions(+), 40 deletions(-) (limited to 'fs/afs/yfsclient.c') diff --git a/fs/afs/yfsclient.c b/fs/afs/yfsclient.c index 6c45d32da13c..abcec145db4b 100644 --- a/fs/afs/yfsclient.c +++ b/fs/afs/yfsclient.c @@ -360,7 +360,6 @@ static int yfs_deliver_fs_fetch_data64(struct afs_call *call) struct afs_vnode_param *vp = &op->file[0]; struct afs_read *req = op->fetch.req; const __be32 *bp; - unsigned int size; int ret; _enter("{%u,%zu, %zu/%llu}", @@ -370,13 +369,14 @@ static int yfs_deliver_fs_fetch_data64(struct afs_call *call) switch (call->unmarshall) { case 0: req->actual_len = 0; - req->index = 0; - req->offset = req->pos & (PAGE_SIZE - 1); afs_extract_to_tmp64(call); call->unmarshall++; fallthrough; - /* extract the returned data length */ + /* Extract the returned data length into ->actual_len. This + * may indicate more or less data than was requested will be + * returned. + */ case 1: _debug("extract data length"); ret = afs_extract_data(call, true); @@ -385,45 +385,25 @@ static int yfs_deliver_fs_fetch_data64(struct afs_call *call) req->actual_len = be64_to_cpu(call->tmp64); _debug("DATA length: %llu", req->actual_len); - req->remain = min(req->len, req->actual_len); - if (req->remain == 0) + + if (req->actual_len == 0) goto no_more_data; + call->iter = req->iter; + call->iov_len = min(req->actual_len, req->len); call->unmarshall++; - - begin_page: - ASSERTCMP(req->index, <, req->nr_pages); - if (req->remain > PAGE_SIZE - req->offset) - size = PAGE_SIZE - req->offset; - else - size = req->remain; - call->iov_len = 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->def_iter, READ, call->bvec, 1, size); - ASSERTCMP(size, <=, PAGE_SIZE); fallthrough; /* extract the returned data */ case 2: _debug("extract data %zu/%llu", - iov_iter_count(call->iter), req->remain); + iov_iter_count(call->iter), req->actual_len); ret = afs_extract_data(call, true); if (ret < 0) return ret; - 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; - req->index++; - if (req->remain > 0) - goto begin_page; - } - ASSERTCMP(req->remain, ==, 0); + call->iter = &call->def_iter; if (req->actual_len <= req->len) goto no_more_data; @@ -469,16 +449,8 @@ static int yfs_deliver_fs_fetch_data64(struct afs_call *call) break; } - for (; req->index < req->nr_pages; req->index++) { - if (req->offset < PAGE_SIZE) - zero_user_segment(req->pages[req->index], - req->offset, PAGE_SIZE); - req->offset = 0; - } - - if (req->page_done) - for (req->index = 0; req->index < req->nr_pages; req->index++) - req->page_done(req); + if (req->done) + req->done(req); _leave(" = 0 [done]"); return 0; @@ -518,6 +490,8 @@ void yfs_fs_fetch_data(struct afs_operation *op) if (!call) return afs_op_nomem(op); + req->call_debug_id = call->debug_id; + /* marshall the parameters */ bp = call->request; bp = xdr_encode_u32(bp, YFSFETCHDATA64); -- cgit v1.2.3-73-gaa49b