From: Peng Tao <tao.peng@xxxxxxx>
For bufferred write, scan dirty pages to find out longest continuous
dirty pages. In this case, also allow layout driver to specify a
maximum layoutget size which is useful to avoid busy scanning dirty pages
for block layout client.
For direct write, just use dreq->bytes_left.
Signed-off-by: Peng Tao <tao.peng@xxxxxxx>
---
fs/nfs/direct.c | 7 ++++++
fs/nfs/internal.h | 1 +
fs/nfs/pnfs.c | 58 +++++++++++++++++++++++++++++++++++++++++++++++++++-
3 files changed, 64 insertions(+), 2 deletions(-)
diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index c39f775..c1899dd 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -46,6 +46,7 @@
#include <linux/kref.h>
#include <linux/slab.h>
#include <linux/task_io_accounting_ops.h>
+#include <linux/module.h>
#include <linux/nfs_fs.h>
#include <linux/nfs_page.h>
@@ -191,6 +192,12 @@ static void nfs_direct_req_release(struct nfs_direct_req *dreq)
kref_put(&dreq->kref, nfs_direct_req_free);
}
+ssize_t nfs_dreq_bytes_left(struct nfs_direct_req *dreq)
+{
+ return dreq->bytes_left;
+}
+EXPORT_SYMBOL_GPL(nfs_dreq_bytes_left);
+
/*
* Collects and returns the final error value/byte-count.
*/
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 31fdb03..e68d329 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -464,6 +464,7 @@ static inline void nfs_inode_dio_wait(struct inode *inode)
{
inode_dio_wait(inode);
}
+extern ssize_t nfs_dreq_bytes_left(struct nfs_direct_req *dreq);
/* nfs4proc.c */
extern void __nfs4_read_done_cb(struct nfs_read_data *);
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 2e00fea..e61a373 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -29,6 +29,7 @@
#include <linux/nfs_fs.h>
#include <linux/nfs_page.h>
+#include <linux/pagevec.h>
#include <linux/module.h>
#include "internal.h"
#include "pnfs.h"
@@ -1172,19 +1173,72 @@ pnfs_generic_pg_init_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *r
}
EXPORT_SYMBOL_GPL(pnfs_generic_pg_init_read);
+/*
+ * Return the number of contiguous bytes in dirty pages for a given inode
+ * starting at page frame idx.
+ */
+static u64 pnfs_num_dirty_bytes(struct inode *inode, pgoff_t idx)
+{
+ struct address_space *mapping = inode->i_mapping;
+ pgoff_t index;
+ struct pagevec pvec;
+ pgoff_t num = 1; /* self */
+ int i, done = 0;
+
+ pagevec_init(&pvec, 0);
+ idx++; /* self */
+ while (!done) {
+ index = idx;
+ pagevec_lookup_tag(&pvec, mapping, &index,
+ PAGECACHE_TAG_DIRTY, (pgoff_t)PAGEVEC_SIZE);
+ if (pagevec_count(&pvec) == 0)
+ break;
+
+ for (i = 0; i < pagevec_count(&pvec); i++) {
+ struct page *page = pvec.pages[i];
+
+ lock_page(page);
+ if (unlikely(page->mapping != mapping) ||
+ !PageDirty(page) ||
+ PageWriteback(page) ||
+ page->index != idx) {
+ done = 1;
+ unlock_page(page);
+ break;
+ }
+ unlock_page(page);
+ if (done)
+ break;
+ idx++;
+ num++;
+ }
+ pagevec_release(&pvec);
+ }
+ return num << PAGE_CACHE_SHIFT;
+}
+
void
-pnfs_generic_pg_init_write(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
+pnfs_generic_pg_init_write(struct nfs_pageio_descriptor *pgio,
+ struct nfs_page *req)
{
+ u64 wb_size;
+
BUG_ON(pgio->pg_lseg != NULL);
if (req->wb_offset != req->wb_pgbase) {
nfs_pageio_reset_write_mds(pgio);
return;
}
+
+ if (pgio->pg_dreq == NULL)
+ wb_size = pnfs_num_dirty_bytes(pgio->pg_inode, req->wb_index);
+ else
+ wb_size = nfs_dreq_bytes_left(pgio->pg_dreq);
+
pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
req->wb_context,
req_offset(req),
- req->wb_bytes,
+ wb_size?:req->wb_bytes,
IOMODE_RW,
GFP_NOFS);
/* If no lseg, fall back to write through mds */
--
1.7.1.262.g5ef3d
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