NFS: Another cleanup of the read/write request coalescing code
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index 7017eb0..5281285 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -225,14 +225,26 @@
/**
* nfs_pageio_init - initialise a page io descriptor
* @desc: pointer to descriptor
- * @iosize: io block size
+ * @inode: pointer to inode
+ * @doio: pointer to io function
+ * @bsize: io block size
+ * @io_flags: extra parameters for the io function
*/
-void nfs_pageio_init(struct nfs_pageio_descriptor *desc, unsigned int bsize)
+void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
+ struct inode *inode,
+ int (*doio)(struct inode *, struct list_head *, size_t, int),
+ unsigned int bsize,
+ int io_flags)
{
INIT_LIST_HEAD(&desc->pg_list);
+ desc->pg_bytes_written = 0;
desc->pg_count = 0;
desc->pg_bsize = bsize;
desc->pg_base = 0;
+ desc->pg_inode = inode;
+ desc->pg_doio = doio;
+ desc->pg_ioflags = io_flags;
+ desc->pg_error = 0;
}
/**
@@ -265,15 +277,15 @@
}
/**
- * nfs_pageio_add_request - Attempt to coalesce a request into a page list.
+ * nfs_pageio_do_add_request - Attempt to coalesce a request into a page list.
* @desc: destination io descriptor
* @req: request
*
* 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,
- struct nfs_page *req)
+static int nfs_pageio_do_add_request(struct nfs_pageio_descriptor *desc,
+ struct nfs_page *req)
{
size_t newlen = req->wb_bytes;
@@ -301,6 +313,46 @@
return 1;
}
+/*
+ * Helper for nfs_pageio_add_request and nfs_pageio_complete
+ */
+static void nfs_pageio_doio(struct nfs_pageio_descriptor *desc)
+{
+ if (!list_empty(&desc->pg_list)) {
+ int error = desc->pg_doio(desc->pg_inode,
+ &desc->pg_list,
+ desc->pg_count,
+ desc->pg_ioflags);
+ if (error < 0)
+ desc->pg_error = error;
+ else
+ desc->pg_bytes_written += desc->pg_count;
+ }
+ if (list_empty(&desc->pg_list)) {
+ desc->pg_count = 0;
+ desc->pg_base = 0;
+ }
+}
+
+/**
+ * nfs_pageio_add_request - Attempt to coalesce a request into a page list.
+ * @desc: destination io descriptor
+ * @req: request
+ *
+ * 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,
+ struct nfs_page *req)
+{
+ while (!nfs_pageio_do_add_request(desc, req)) {
+ nfs_pageio_doio(desc);
+ if (desc->pg_error < 0)
+ return 0;
+ }
+ return 1;
+}
+
/**
* nfs_pageio_add_list - Split coalesced requests out from a list.
* @desc: destination io descriptor
@@ -320,6 +372,15 @@
}
}
+/**
+ * nfs_pageio_complete - Complete I/O on an nfs_pageio_descriptor
+ * @desc: pointer to io descriptor
+ */
+void nfs_pageio_complete(struct nfs_pageio_descriptor *desc)
+{
+ nfs_pageio_doio(desc);
+}
+
#define NFS_SCAN_MAXENTRIES 16
/**
* nfs_scan_dirty - Scan the radix tree for dirty requests
diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index 97f0f42..0effa74 100644
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -27,7 +27,8 @@
#define NFSDBG_FACILITY NFSDBG_PAGECACHE
-static int nfs_pagein_one(struct list_head *, struct inode *);
+static int nfs_pagein_multi(struct inode *, struct list_head *, size_t, int);
+static int nfs_pagein_one(struct inode *, struct list_head *, size_t, int);
static const struct rpc_call_ops nfs_read_partial_ops;
static const struct rpc_call_ops nfs_read_full_ops;
@@ -133,7 +134,10 @@
memclear_highpage_flush(page, len, PAGE_CACHE_SIZE - len);
nfs_list_add_request(new, &one_request);
- nfs_pagein_one(&one_request, inode);
+ if (NFS_SERVER(inode)->rsize < PAGE_CACHE_SIZE)
+ nfs_pagein_multi(inode, &one_request, len, 0);
+ else
+ nfs_pagein_one(inode, &one_request, len, 0);
return 0;
}
@@ -230,7 +234,7 @@
* 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 list_head *head, struct inode *inode)
+static int nfs_pagein_multi(struct inode *inode, struct list_head *head, size_t count, int flags)
{
struct nfs_page *req = nfs_list_entry(head->next);
struct page *page = req->wb_page;
@@ -242,7 +246,7 @@
nfs_list_remove_request(req);
- nbytes = req->wb_bytes;
+ nbytes = count;
do {
size_t len = min(nbytes,rsize);
@@ -258,23 +262,19 @@
ClearPageError(page);
offset = 0;
- nbytes = req->wb_bytes;
+ nbytes = count;
do {
data = list_entry(list.next, struct nfs_read_data, pages);
list_del_init(&data->pages);
data->pagevec[0] = page;
- if (nbytes > rsize) {
- nfs_read_rpcsetup(req, data, &nfs_read_partial_ops,
- rsize, offset);
- offset += rsize;
- nbytes -= rsize;
- } else {
- nfs_read_rpcsetup(req, data, &nfs_read_partial_ops,
- nbytes, offset);
- nbytes = 0;
- }
+ if (nbytes < rsize)
+ rsize = nbytes;
+ nfs_read_rpcsetup(req, data, &nfs_read_partial_ops,
+ rsize, offset);
+ offset += rsize;
+ nbytes -= rsize;
nfs_execute_read(data);
} while (nbytes != 0);
@@ -291,30 +291,24 @@
return -ENOMEM;
}
-static int nfs_pagein_one(struct list_head *head, struct inode *inode)
+static int nfs_pagein_one(struct inode *inode, struct list_head *head, size_t count, int flags)
{
struct nfs_page *req;
struct page **pages;
struct nfs_read_data *data;
- unsigned int count;
- if (NFS_SERVER(inode)->rsize < PAGE_CACHE_SIZE)
- return nfs_pagein_multi(head, inode);
-
- data = nfs_readdata_alloc(NFS_SERVER(inode)->rsize);
+ data = nfs_readdata_alloc(count);
if (!data)
goto out_bad;
INIT_LIST_HEAD(&data->pages);
pages = data->pagevec;
- count = 0;
while (!list_empty(head)) {
req = nfs_list_entry(head->next);
nfs_list_remove_request(req);
nfs_list_add_request(req, &data->pages);
ClearPageError(req->wb_page);
*pages++ = req->wb_page;
- count += req->wb_bytes;
}
req = nfs_list_entry(data->pages.next);
@@ -328,22 +322,20 @@
}
static int
-nfs_pagein_list(struct list_head *head, unsigned int rsize)
+nfs_pagein_list(struct inode *inode, struct list_head *head, unsigned int rsize)
{
struct nfs_pageio_descriptor desc;
- struct nfs_page *req;
unsigned int pages = 0;
int error = 0;
- while (!list_empty(head)) {
- nfs_pageio_init(&desc, rsize);
- nfs_pageio_add_list(&desc, head);
- req = nfs_list_entry(desc.pg_list.next);
- error = nfs_pagein_one(&desc.pg_list, req->wb_context->dentry->d_inode);
- if (error < 0)
- break;
- pages += (desc.pg_count + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
- }
+ 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)
@@ -597,7 +589,7 @@
filp->private_data);
ret = read_cache_pages(mapping, pages, readpage_async_filler, &desc);
if (!list_empty(&head)) {
- int err = nfs_pagein_list(&head, server->rsize);
+ int err = nfs_pagein_list(inode, &head, server->rsize);
if (!ret)
nfs_add_stats(inode, NFSIOS_READPAGES, err);
ret = err;
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index b03ec1ba..b674996 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -835,7 +835,7 @@
* Generate multiple small requests to write out a single
* contiguous dirty area on one page.
*/
-static int nfs_flush_multi(struct inode *inode, struct list_head *head, int how)
+static int nfs_flush_multi(struct inode *inode, struct list_head *head, size_t count, int how)
{
struct nfs_page *req = nfs_list_entry(head->next);
struct page *page = req->wb_page;
@@ -847,7 +847,7 @@
nfs_list_remove_request(req);
- nbytes = req->wb_bytes;
+ nbytes = count;
do {
size_t len = min(nbytes, wsize);
@@ -862,23 +862,19 @@
ClearPageError(page);
offset = 0;
- nbytes = req->wb_bytes;
+ nbytes = count;
do {
data = list_entry(list.next, struct nfs_write_data, pages);
list_del_init(&data->pages);
data->pagevec[0] = page;
- if (nbytes > wsize) {
- nfs_write_rpcsetup(req, data, &nfs_write_partial_ops,
- wsize, offset, how);
- offset += wsize;
- nbytes -= wsize;
- } else {
- nfs_write_rpcsetup(req, data, &nfs_write_partial_ops,
- nbytes, offset, how);
- nbytes = 0;
- }
+ if (nbytes < wsize)
+ wsize = nbytes;
+ nfs_write_rpcsetup(req, data, &nfs_write_partial_ops,
+ wsize, offset, how);
+ offset += wsize;
+ nbytes -= wsize;
nfs_execute_write(data);
} while (nbytes != 0);
@@ -904,26 +900,23 @@
* This is the case if nfs_updatepage detects a conflicting request
* that has been written but not committed.
*/
-static int nfs_flush_one(struct inode *inode, struct list_head *head, int how)
+static int nfs_flush_one(struct inode *inode, struct list_head *head, size_t count, int how)
{
struct nfs_page *req;
struct page **pages;
struct nfs_write_data *data;
- unsigned int count;
- data = nfs_writedata_alloc(NFS_SERVER(inode)->wsize);
+ data = nfs_writedata_alloc(count);
if (!data)
goto out_bad;
pages = data->pagevec;
- count = 0;
while (!list_empty(head)) {
req = nfs_list_entry(head->next);
nfs_list_remove_request(req);
nfs_list_add_request(req, &data->pages);
ClearPageError(req->wb_page);
*pages++ = req->wb_page;
- count += req->wb_bytes;
}
req = nfs_list_entry(data->pages.next);
@@ -946,28 +939,22 @@
static int nfs_flush_list(struct inode *inode, struct list_head *head, int npages, int how)
{
struct nfs_pageio_descriptor desc;
- int (*flush_one)(struct inode *, struct list_head *, int);
int wpages = NFS_SERVER(inode)->wpages;
int wsize = NFS_SERVER(inode)->wsize;
- int error;
- flush_one = nfs_flush_one;
- if (wsize < PAGE_CACHE_SIZE)
- flush_one = nfs_flush_multi;
/* For single writes, FLUSH_STABLE is more efficient */
if (npages <= wpages && npages == NFS_I(inode)->npages
&& nfs_list_entry(head->next)->wb_bytes <= wsize)
how |= FLUSH_STABLE;
- do {
- nfs_pageio_init(&desc, wsize);
- nfs_pageio_add_list(&desc, head);
- error = flush_one(inode, &desc.pg_list, how);
- if (error < 0)
- goto out_err;
- } while (!list_empty(head));
- return 0;
-out_err:
+ if (wsize < PAGE_CACHE_SIZE)
+ nfs_pageio_init(&desc, inode, nfs_flush_multi, wsize, how);
+ else
+ nfs_pageio_init(&desc, inode, nfs_flush_one, wsize, how);
+ nfs_pageio_add_list(&desc, head);
+ nfs_pageio_complete(&desc);
+ if (desc.pg_error == 0)
+ return 0;
while (!list_empty(head)) {
struct nfs_page *req = nfs_list_entry(head->next);
nfs_list_remove_request(req);
@@ -975,7 +962,7 @@
nfs_end_page_writeback(req->wb_page);
nfs_clear_page_writeback(req);
}
- return error;
+ return desc.pg_error;
}
/*
