From ef2c488c073f4f0b3a200745dd8d608c01d69c39 Mon Sep 17 00:00:00 2001 From: Anna Schumaker Date: Tue, 6 May 2014 09:12:36 -0400 Subject: NFS: Create a generic_pgio function These functions are almost identical on both the read and write side. FLUSH_COND_STABLE will never be set for the read path, so leaving it in the generic code won't hurt anything. Signed-off-by: Anna Schumaker Signed-off-by: Trond Myklebust --- fs/nfs/pagelist.c | 106 +++++++++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 101 insertions(+), 5 deletions(-) (limited to 'fs/nfs/pagelist.c') diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c index b0a98daae14c..d8d25a4deb88 100644 --- a/fs/nfs/pagelist.c +++ b/fs/nfs/pagelist.c @@ -27,6 +27,7 @@ #define NFSDBG_FACILITY NFSDBG_PAGECACHE static struct kmem_cache *nfs_page_cachep; +static const struct rpc_call_ops nfs_pgio_common_ops; static bool nfs_pgarray_set(struct nfs_page_array *p, unsigned int pagecount) { @@ -338,8 +339,8 @@ EXPORT_SYMBOL_GPL(nfs_rw_header_free); * @hdr: The header making a request * @pagecount: Number of pages to create */ -struct nfs_pgio_data *nfs_pgio_data_alloc(struct nfs_pgio_header *hdr, - unsigned int pagecount) +static struct nfs_pgio_data *nfs_pgio_data_alloc(struct nfs_pgio_header *hdr, + unsigned int pagecount) { struct nfs_pgio_data *data, *prealloc; @@ -396,7 +397,7 @@ EXPORT_SYMBOL_GPL(nfs_pgio_data_release); * @how: How to commit data (writes only) * @cinfo: Commit information for the call (writes only) */ -void nfs_pgio_rpcsetup(struct nfs_pgio_data *data, +static void nfs_pgio_rpcsetup(struct nfs_pgio_data *data, unsigned int count, unsigned int offset, int how, struct nfs_commit_info *cinfo) { @@ -451,7 +452,7 @@ static void nfs_pgio_prepare(struct rpc_task *task, void *calldata) * @desc: IO descriptor * @hdr: pageio header */ -int nfs_pgio_error(struct nfs_pageio_descriptor *desc, +static int nfs_pgio_error(struct nfs_pageio_descriptor *desc, struct nfs_pgio_header *hdr) { struct nfs_pgio_data *data; @@ -534,6 +535,101 @@ 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. + * + * It may happen that the page we're passed is not marked dirty. + * 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) +{ + struct nfs_page *req; + struct page **pages; + struct nfs_pgio_data *data; + struct list_head *head = &desc->pg_list; + struct nfs_commit_info cinfo; + + data = nfs_pgio_data_alloc(hdr, nfs_page_array_len(desc->pg_base, + desc->pg_count)); + if (!data) + return nfs_pgio_error(desc, hdr); + + nfs_init_cinfo(&cinfo, desc->pg_inode, desc->pg_dreq); + pages = data->pages.pagevec; + while (!list_empty(head)) { + req = nfs_list_entry(head->next); + nfs_list_remove_request(req); + nfs_list_add_request(req, &hdr->pages); + *pages++ = req->wb_page; + } + + if ((desc->pg_ioflags & FLUSH_COND_STABLE) && + (desc->pg_moreio || nfs_reqs_to_commit(&cinfo))) + desc->pg_ioflags &= ~FLUSH_COND_STABLE; + + /* Set up the argument struct */ + nfs_pgio_rpcsetup(data, desc->pg_count, 0, desc->pg_ioflags, &cinfo); + list_add(&data->list, &hdr->rpc_list); + desc->pg_rpc_callops = &nfs_pgio_common_ops; + return 0; +} + +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) { @@ -741,7 +837,7 @@ void nfs_destroy_nfspagecache(void) kmem_cache_destroy(nfs_page_cachep); } -const struct rpc_call_ops nfs_pgio_common_ops = { +static const struct rpc_call_ops nfs_pgio_common_ops = { .rpc_call_prepare = nfs_pgio_prepare, .rpc_call_done = nfs_pgio_result, .rpc_release = nfs_pgio_release, -- cgit 1.4.1