提交 8b09bee3 编写于 作者: T Trond Myklebust

NFS: Cleanup for nfs_readpages()

Do the coalescing of read requests into block sized requests at start of
I/O as we scan through the pages instead of going through a second pass.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
上级 bcb71bba
......@@ -342,7 +342,7 @@ static void nfs_pageio_doio(struct nfs_pageio_descriptor *desc)
* Returns true if the request 'req' was successfully coalesced into the
* existing list of pages 'desc'.
*/
static int nfs_pageio_add_request(struct nfs_pageio_descriptor *desc,
int nfs_pageio_add_request(struct nfs_pageio_descriptor *desc,
struct nfs_page *req)
{
while (!nfs_pageio_do_add_request(desc, req)) {
......
......@@ -321,28 +321,6 @@ static int nfs_pagein_one(struct inode *inode, struct list_head *head, size_t co
return -ENOMEM;
}
static int
nfs_pagein_list(struct inode *inode, struct list_head *head, unsigned int rsize)
{
struct nfs_pageio_descriptor desc;
unsigned int pages = 0;
int error = 0;
if (rsize < PAGE_CACHE_SIZE)
nfs_pageio_init(&desc, inode, nfs_pagein_multi, rsize, 0);
else
nfs_pageio_init(&desc, inode, nfs_pagein_one, rsize, 0);
nfs_pageio_add_list(&desc, head);
nfs_pageio_complete(&desc);
pages += (desc.pg_bytes_written + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
nfs_async_read_error(head);
if (error >= 0)
return pages;
return error;
}
/*
* This is the callback from RPC telling us whether a reply was
* received or some error occurred (timeout or socket shutdown).
......@@ -532,7 +510,7 @@ int nfs_readpage(struct file *file, struct page *page)
}
struct nfs_readdesc {
struct list_head *head;
struct nfs_pageio_descriptor *pgio;
struct nfs_open_context *ctx;
};
......@@ -556,19 +534,21 @@ readpage_async_filler(void *data, struct page *page)
}
if (len < PAGE_CACHE_SIZE)
memclear_highpage_flush(page, len, PAGE_CACHE_SIZE - len);
nfs_list_add_request(new, desc->head);
nfs_pageio_add_request(desc->pgio, new);
return 0;
}
int nfs_readpages(struct file *filp, struct address_space *mapping,
struct list_head *pages, unsigned nr_pages)
{
LIST_HEAD(head);
struct nfs_pageio_descriptor pgio;
struct nfs_readdesc desc = {
.head = &head,
.pgio = &pgio,
};
struct inode *inode = mapping->host;
struct nfs_server *server = NFS_SERVER(inode);
size_t rsize = server->rsize;
unsigned long npages;
int ret = -ESTALE;
dprintk("NFS: nfs_readpages (%s/%Ld %d)\n",
......@@ -587,13 +567,16 @@ int nfs_readpages(struct file *filp, struct address_space *mapping,
} else
desc.ctx = get_nfs_open_context((struct nfs_open_context *)
filp->private_data);
if (rsize < PAGE_CACHE_SIZE)
nfs_pageio_init(&pgio, inode, nfs_pagein_multi, rsize, 0);
else
nfs_pageio_init(&pgio, inode, nfs_pagein_one, rsize, 0);
ret = read_cache_pages(mapping, pages, readpage_async_filler, &desc);
if (!list_empty(&head)) {
int err = nfs_pagein_list(inode, &head, server->rsize);
if (!ret)
nfs_add_stats(inode, NFSIOS_READPAGES, err);
ret = err;
}
nfs_pageio_complete(&pgio);
npages = (pgio.pg_bytes_written + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
nfs_add_stats(inode, NFSIOS_READPAGES, npages);
put_nfs_open_context(desc.ctx);
out:
return ret;
......
......@@ -82,6 +82,8 @@ extern void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
int (*doio)(struct inode *, struct list_head *, size_t, int),
size_t bsize,
int how);
extern int nfs_pageio_add_request(struct nfs_pageio_descriptor *,
struct nfs_page *);
extern void nfs_pageio_add_list(struct nfs_pageio_descriptor *,
struct list_head *);
extern void nfs_pageio_complete(struct nfs_pageio_descriptor *desc);
......
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