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authorAnna Schumaker <Anna.Schumaker@netapp.com>2014-05-06 09:12:36 -0400
committerTrond Myklebust <trond.myklebust@primarydata.com>2014-05-28 18:41:12 -0400
commitef2c488c073f4f0b3a200745dd8d608c01d69c39 (patch)
tree7bb53a2479bb8df2bb66b0943f4814e0abb20f8b /fs/nfs/read.c
parent844c9e691d8723853ca8f2de0207683538645824 (diff)
downloadlwn-ef2c488c073f4f0b3a200745dd8d608c01d69c39.tar.gz
lwn-ef2c488c073f4f0b3a200745dd8d608c01d69c39.zip
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 <Anna.Schumaker@Netapp.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Diffstat (limited to 'fs/nfs/read.c')
-rw-r--r--fs/nfs/read.c81
1 files changed, 1 insertions, 80 deletions
diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index 64f8eefec76a..4fcef82d78b4 100644
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -237,85 +237,6 @@ static const struct nfs_pgio_completion_ops nfs_async_read_completion_ops = {
.completion = nfs_read_completion,
};
-/*
- * Generate multiple requests to fill a single page.
- *
- * We optimize to reduce the number of read operations on the wire. If we
- * detect that we're reading a page, or an area of a page, that is past the
- * end of file, we do not generate NFS read operations but just clear the
- * parts of the page that would have come back zero from the server anyway.
- *
- * We rely on the cached value of i_size to make this determination; another
- * client can fill pages on the server past our cached end-of-file, but we
- * won't see the new data until our attribute cache is updated. This is more
- * or less conventional NFS client behavior.
- */
-static int nfs_pagein_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 rsize = desc->pg_bsize, nbytes;
- unsigned int offset;
-
- offset = 0;
- nbytes = desc->pg_count;
- do {
- size_t len = min(nbytes,rsize);
-
- 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, 0, NULL);
- list_add(&data->list, &hdr->rpc_list);
- 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;
-}
-
-static int nfs_pagein_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;
-
- data = nfs_pgio_data_alloc(hdr, nfs_page_array_len(desc->pg_base,
- desc->pg_count));
- if (!data)
- return nfs_pgio_error(desc, hdr);
-
- 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;
- }
-
- nfs_pgio_rpcsetup(data, desc->pg_count, 0, 0, NULL);
- list_add(&data->list, &hdr->rpc_list);
- desc->pg_rpc_callops = &nfs_pgio_common_ops;
- return 0;
-}
-
-int nfs_generic_pagein(struct nfs_pageio_descriptor *desc,
- struct nfs_pgio_header *hdr)
-{
- if (desc->pg_bsize < PAGE_CACHE_SIZE)
- return nfs_pagein_multi(desc, hdr);
- return nfs_pagein_one(desc, hdr);
-}
-EXPORT_SYMBOL_GPL(nfs_generic_pagein);
-
static int nfs_generic_pg_readpages(struct nfs_pageio_descriptor *desc)
{
struct nfs_rw_header *rhdr;
@@ -330,7 +251,7 @@ static int nfs_generic_pg_readpages(struct nfs_pageio_descriptor *desc)
hdr = &rhdr->header;
nfs_pgheader_init(desc, hdr, nfs_rw_header_free);
atomic_inc(&hdr->refcnt);
- ret = nfs_generic_pagein(desc, hdr);
+ ret = nfs_generic_pgio(desc, hdr);
if (ret == 0)
ret = nfs_do_multiple_reads(&hdr->rpc_list,
desc->pg_rpc_callops);