by Myklebust, Trond

[permalink] [raw]

Subject: [PATCH 3/8] NFS: Cache rpc_ops in struct nfs_pageio_descriptor

Signed-off-by: Trond Myklebust <[email protected]>
---
fs/nfs/read.c | 19 ++++++++-----------
fs/nfs/write.c | 20 +++++++-------------
include/linux/nfs_page.h | 1 +
3 files changed, 16 insertions(+), 24 deletions(-)

diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index d30d6de..b2e9aad 100644
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -327,6 +327,7 @@ static int nfs_pagein_multi(struct nfs_pageio_descriptor *desc, struct list_head
} while(nbytes != 0);
atomic_set(&req->wb_complete, requests);
ClearPageError(page);
+ desc->pg_rpc_callops = &nfs_read_partial_ops;
return ret;
out_bad:
while (!list_empty(res)) {
@@ -366,6 +367,7 @@ static int nfs_pagein_one(struct nfs_pageio_descriptor *desc, struct list_head *

nfs_read_rpcsetup(req, data, desc->pg_count, 0);
list_add(&data->list, res);
+ desc->pg_rpc_callops = &nfs_read_full_ops;
out:
return ret;
}
@@ -375,19 +377,14 @@ int nfs_generic_pg_readpages(struct nfs_pageio_descriptor *desc)
LIST_HEAD(head);
int ret;

- if (desc->pg_bsize < PAGE_CACHE_SIZE) {
+ if (desc->pg_bsize < PAGE_CACHE_SIZE)
ret = nfs_pagein_multi(desc, &head);
- if (ret == 0)
- ret = nfs_do_multiple_reads(&head,
- &nfs_read_partial_ops,
- desc->pg_lseg);
- } else {
+ else
ret = nfs_pagein_one(desc, &head);
- if (ret == 0)
- ret = nfs_do_multiple_reads(&head,
- &nfs_read_full_ops,
- desc->pg_lseg);
- }
+
+ if (ret == 0)
+ ret = nfs_do_multiple_reads(&head, desc->pg_rpc_callops,
+ desc->pg_lseg);
put_lseg(desc->pg_lseg);
desc->pg_lseg = NULL;
return ret;
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 89cc687..8fa7def 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -975,6 +975,7 @@ static int nfs_flush_multi(struct nfs_pageio_descriptor *desc, struct list_head
offset += len;
} while (nbytes != 0);
atomic_set(&req->wb_complete, requests);
+ desc->pg_rpc_callops = &nfs_write_partial_ops;
return ret;

out_bad:
@@ -1031,6 +1032,7 @@ static int nfs_flush_one(struct nfs_pageio_descriptor *desc, struct list_head *r
/* Set up the argument struct */
nfs_write_rpcsetup(req, data, desc->pg_count, 0, desc->pg_ioflags);
list_add(&data->list, res);
+ desc->pg_rpc_callops = &nfs_write_full_ops;
out:
return ret;
}
@@ -1040,21 +1042,13 @@ int nfs_generic_pg_writepages(struct nfs_pageio_descriptor *desc)
LIST_HEAD(head);
int ret;

- if (desc->pg_bsize < PAGE_CACHE_SIZE) {
+ if (desc->pg_bsize < PAGE_CACHE_SIZE)
ret = nfs_flush_multi(desc, &head);
- if (ret == 0)
- ret = nfs_do_multiple_writes(&head,
- &nfs_write_partial_ops,
- desc->pg_lseg,
- desc->pg_ioflags);
- } else {
+ else
ret = nfs_flush_one(desc, &head);
- if (ret == 0)
- ret = nfs_do_multiple_writes(&head,
- &nfs_write_full_ops,
- desc->pg_lseg,
- desc->pg_ioflags);
- }
+ if (ret == 0)
+ ret = nfs_do_multiple_writes(&head, desc->pg_rpc_callops,
+ desc->pg_lseg, desc->pg_ioflags);
put_lseg(desc->pg_lseg);
desc->pg_lseg = NULL;
return ret;
diff --git a/include/linux/nfs_page.h b/include/linux/nfs_page.h
index 9ac2dd1..db3194f 100644
--- a/include/linux/nfs_page.h
+++ b/include/linux/nfs_page.h
@@ -74,6 +74,7 @@ struct nfs_pageio_descriptor {
const struct nfs_pageio_ops *pg_ops;
int pg_ioflags;
int pg_error;
+ const struct rpc_call_ops *pg_rpc_callops;
struct pnfs_layout_segment *pg_lseg;
};

--
1.7.6

2011-07-12 19:30:09

by Myklebust, Trond

[permalink] [raw]

Subject: [PATCH 5/8] NFS: Allow the nfs_pageio_descriptor to signal that a re-coalesce is needed

If an attempt to do pNFS fails, and we have to fall back to writing through
the MDS, then we may want to re-coalesce the requests that we already have
since the block size for the MDS read/writes may be different to that of
the DS read/writes.

Signed-off-by: Trond Myklebust <[email protected]>
---
fs/nfs/pagelist.c | 57 +++++++++++++++++++++++++++++++++++++++++++--
include/linux/nfs_page.h | 3 +-
2 files changed, 56 insertions(+), 4 deletions(-)

diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index d421e19..7139dbf 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -240,6 +240,7 @@ void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
desc->pg_bsize = bsize;
desc->pg_base = 0;
desc->pg_moreio = 0;
+ desc->pg_recoalesce = 0;
desc->pg_inode = inode;
desc->pg_ops = pg_ops;
desc->pg_ioflags = io_flags;
@@ -331,7 +332,7 @@ 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'.
*/
-int nfs_pageio_add_request(struct nfs_pageio_descriptor *desc,
+static int __nfs_pageio_add_request(struct nfs_pageio_descriptor *desc,
struct nfs_page *req)
{
while (!nfs_pageio_do_add_request(desc, req)) {
@@ -340,17 +341,67 @@ int nfs_pageio_add_request(struct nfs_pageio_descriptor *desc,
if (desc->pg_error < 0)
return 0;
desc->pg_moreio = 0;
+ if (desc->pg_recoalesce)
+ return 0;
}
return 1;
}

+static int nfs_do_recoalesce(struct nfs_pageio_descriptor *desc)
+{
+ LIST_HEAD(head);
+
+ do {
+ list_splice_init(&desc->pg_list, &head);
+ desc->pg_bytes_written -= desc->pg_count;
+ desc->pg_count = 0;
+ desc->pg_base = 0;
+ desc->pg_recoalesce = 0;
+
+ while (!list_empty(&head)) {
+ struct nfs_page *req;
+
+ req = list_first_entry(&head, struct nfs_page, wb_list);
+ nfs_list_remove_request(req);
+ if (__nfs_pageio_add_request(desc, req))
+ continue;
+ if (desc->pg_error < 0)
+ return 0;
+ break;
+ }
+ } while (desc->pg_recoalesce);
+ return 1;
+}
+
+int nfs_pageio_add_request(struct nfs_pageio_descriptor *desc,
+ struct nfs_page *req)
+{
+ int ret;
+
+ do {
+ ret = __nfs_pageio_add_request(desc, req);
+ if (ret)
+ break;
+ if (desc->pg_error < 0)
+ break;
+ ret = nfs_do_recoalesce(desc);
+ } while (ret);
+ return ret;
+}
+
/**
* 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);
+ for (;;) {
+ nfs_pageio_doio(desc);
+ if (!desc->pg_recoalesce)
+ break;
+ if (!nfs_do_recoalesce(desc))
+ break;
+ }
}

/**
@@ -369,7 +420,7 @@ void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *desc, pgoff_t index)
if (!list_empty(&desc->pg_list)) {
struct nfs_page *prev = nfs_list_entry(desc->pg_list.prev);
if (index != prev->wb_index + 1)
- nfs_pageio_doio(desc);
+ nfs_pageio_complete(desc);
}
}

diff --git a/include/linux/nfs_page.h b/include/linux/nfs_page.h
index db3194f..7241b2a 100644
--- a/include/linux/nfs_page.h
+++ b/include/linux/nfs_page.h
@@ -68,7 +68,8 @@ struct nfs_pageio_descriptor {
size_t pg_count;
size_t pg_bsize;
unsigned int pg_base;
- char pg_moreio;
+ unsigned char pg_moreio : 1,
+ pg_recoalesce : 1;

struct inode *pg_inode;
const struct nfs_pageio_ops *pg_ops;
--
1.7.6