From f0cb9ab8d5589fc553761068200e5a8342f61de0 Mon Sep 17 00:00:00 2001 From: Weston Andros Adamson Date: Thu, 15 May 2014 11:56:52 -0400 Subject: [PATCH] nfs: use > 1 request to handle bsize < PAGE_SIZE Use the newly added support for multiple requests per page for rsize/wsize < PAGE_SIZE, instead of having multiple read / write data structures per pageio header. This allows us to get rid of nfs_pgio_multi. Signed-off-by: Weston Andros Adamson Signed-off-by: Trond Myklebust --- fs/nfs/pagelist.c | 80 +++++++---------------------------------------- 1 file changed, 11 insertions(+), 69 deletions(-) diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c index 838f7c9664f5..ec4311df05d9 100644 --- a/fs/nfs/pagelist.c +++ b/fs/nfs/pagelist.c @@ -443,21 +443,13 @@ nfs_wait_on_request(struct nfs_page *req) size_t nfs_generic_pg_test(struct nfs_pageio_descriptor *desc, struct nfs_page *prev, struct nfs_page *req) { - if (!prev) - return req->wb_bytes; - /* - * FIXME: ideally we should be able to coalesce all requests - * that are not block boundary aligned, but currently this - * is problematic for the case of bsize < PAGE_CACHE_SIZE, - * since nfs_flush_multi and nfs_pagein_multi assume you - * can have only one struct nfs_page. - */ - if (desc->pg_bsize < PAGE_SIZE) + if (desc->pg_count > desc->pg_bsize) { + /* should never happen */ + WARN_ON_ONCE(1); return 0; + } - if (desc->pg_count + req->wb_bytes <= desc->pg_bsize) - return req->wb_bytes; - return 0; + return min(desc->pg_bsize - desc->pg_count, (size_t)req->wb_bytes); } EXPORT_SYMBOL_GPL(nfs_generic_pg_test); @@ -765,50 +757,6 @@ static void nfs_pgio_result(struct rpc_task *task, void *calldata) data->header->rw_ops->rw_result(task, data); } -/* - * Generate multiple small requests to read or write a single - * contiguous dirty on one page. - */ -static int nfs_pgio_multi(struct nfs_pageio_descriptor *desc, - struct nfs_pgio_header *hdr) -{ - struct nfs_page *req = hdr->req; - struct page *page = req->wb_page; - struct nfs_pgio_data *data; - size_t wsize = desc->pg_bsize, nbytes; - unsigned int offset; - int requests = 0; - struct nfs_commit_info cinfo; - - nfs_init_cinfo(&cinfo, desc->pg_inode, desc->pg_dreq); - - if ((desc->pg_ioflags & FLUSH_COND_STABLE) && - (desc->pg_moreio || nfs_reqs_to_commit(&cinfo) || - desc->pg_count > wsize)) - desc->pg_ioflags &= ~FLUSH_COND_STABLE; - - offset = 0; - nbytes = desc->pg_count; - do { - size_t len = min(nbytes, wsize); - - data = nfs_pgio_data_alloc(hdr, 1); - if (!data) - return nfs_pgio_error(desc, hdr); - data->pages.pagevec[0] = page; - nfs_pgio_rpcsetup(data, len, offset, desc->pg_ioflags, &cinfo); - list_add(&data->list, &hdr->rpc_list); - requests++; - nbytes -= len; - offset += len; - } while (nbytes != 0); - - nfs_list_remove_request(req); - nfs_list_add_request(req, &hdr->pages); - desc->pg_rpc_callops = &nfs_pgio_common_ops; - return 0; -} - /* * Create an RPC task for the given read or write request and kick it. * The page must have been locked by the caller. @@ -817,8 +765,8 @@ static int nfs_pgio_multi(struct nfs_pageio_descriptor *desc, * This is the case if nfs_updatepage detects a conflicting request * that has been written but not committed. */ -static int nfs_pgio_one(struct nfs_pageio_descriptor *desc, - struct nfs_pgio_header *hdr) +int nfs_generic_pgio(struct nfs_pageio_descriptor *desc, + struct nfs_pgio_header *hdr) { struct nfs_page *req; struct page **pages; @@ -850,6 +798,7 @@ static int nfs_pgio_one(struct nfs_pageio_descriptor *desc, desc->pg_rpc_callops = &nfs_pgio_common_ops; return 0; } +EXPORT_SYMBOL_GPL(nfs_generic_pgio); static int nfs_generic_pg_pgios(struct nfs_pageio_descriptor *desc) { @@ -875,15 +824,6 @@ static int nfs_generic_pg_pgios(struct nfs_pageio_descriptor *desc) return ret; } -int nfs_generic_pgio(struct nfs_pageio_descriptor *desc, - struct nfs_pgio_header *hdr) -{ - if (desc->pg_bsize < PAGE_CACHE_SIZE) - return nfs_pgio_multi(desc, hdr); - return nfs_pgio_one(desc, hdr); -} -EXPORT_SYMBOL_GPL(nfs_generic_pgio); - static bool nfs_match_open_context(const struct nfs_open_context *ctx1, const struct nfs_open_context *ctx2) { @@ -925,7 +865,9 @@ static bool nfs_can_coalesce_requests(struct nfs_page *prev, return false; } size = pgio->pg_ops->pg_test(pgio, prev, req); - WARN_ON_ONCE(size && size != req->wb_bytes); + WARN_ON_ONCE(size > req->wb_bytes); + if (size && size < req->wb_bytes) + req->wb_bytes = size; return size > 0; } -- 2.20.1