[PATCH 35/37] NFS: Store pages from an NFS inode into a local cache

David Howells
2008-02-08T17:13:05Z

Store pages from an NFS inode into the cache data storage object associated
with that inode.

Signed-off-by: David Howells <dhowells@redhat.com>
---

fs/nfs/fscache.c | 26 ++++++++++++++++++++++++++
fs/nfs/fscache.h | 16 ++++++++++++++++
fs/nfs/read.c | 5 +++++
3 files changed, 47 insertions(+), 0 deletions(-)

diff --git a/fs/nfs/fscache.c b/fs/nfs/fscache.c
index 438cc9b..50ae70f 100644
--- a/fs/nfs/fscache.c
+++ b/fs/nfs/fscache.c
@@ -456,3 +456,29 @@ int __nfs_readpages_from_fscache(struct nfs_open_context *ctx,

return ret;
}
+
+/*
+ * Store a newly fetched page in fscache
+ * - PG_fscache must be set on the page
+ */
+void __nfs_readpage_to_fscache(struct inode *inode, struct page *page, int sync)
+{
+ int ret;
+
+ dfprintk(FSCACHE,
+ "NFS: readpage_to_fscache(fsc:%p/p:%p(i:%lx f:%lx)/%d)\n",
+ NFS_I(inode)->fscache, page, page->index, page->flags, sync);
+
+ ret = fscache_write_page(NFS_I(inode)->fscache, page, GFP_KERNEL);
+ dfprintk(FSCACHE,
+ "NFS: readpage_to_fscache: p:%p(i:%lu f:%lx) ret %d\n",
+ page, page->index, page->flags, ret);
+
+ if (ret != 0) {
+ fscache_uncache_page(NFS_I(inode)->fscache, page);
+ nfs_add_stats(inode, NFSIOS_FSCACHE_WRITE_FAIL, 1);
+ nfs_add_stats(inode, NFSIOS_FSCACHE_UNCACHE, 1);
+ } else {
+ nfs_add_stats(inode, NFSIOS_FSCACHE_WRITE_OK, 1);
+ }
+}
diff --git a/fs/nfs/fscache.h b/fs/nfs/fscache.h
index 4c1e1a8..6264cd8 100644
--- a/fs/nfs/fscache.h
+++ b/fs/nfs/fscache.h
@@ -94,6 +94,7 @@ extern int __nfs_readpage_from_fscache(struct nfs_open_context *,
extern int __nfs_readpages_from_fscache(struct nfs_open_context *,
struct inode *, struct address_space *,
struct list_head *, unsigned *);
+extern void __nfs_readpage_to_fscache(struct inode *, struct page *, int);

/*
* release the caching state associated with a page if undergoing complete page
@@ -133,6 +134,19 @@ static inline int nfs_readpages_from_fscache(struct nfs_open_context *ctx,
return -ENOBUFS;
}

+/*
+ * Store a page newly fetched from the server in an inode data storage object
+ * in the cache.
+ */
+static inline void nfs_readpage_to_fscache(struct inode *inode,
+ struct page *page,
+ int sync)
+{
+ if (PageFsCache(page))
+ __nfs_readpage_to_fscache(inode, page, sync);
+}
+
+
#else /* CONFIG_NFS_FSCACHE */
static inline int nfs_fscache_register(void) { return 0; }
static inline void nfs_fscache_unregister(void) {}
@@ -178,6 +192,8 @@ static inline int nfs_readpages_from_fscache(struct nfs_open_context *ctx,
{
return -ENOBUFS;
}
+static inline void nfs_readpage_to_fscache(struct inode *inode,
+ struct page *page, int sync) {}

#endif /* CONFIG_NFS_FSCACHE */
#endif /* _NFS_FSCACHE_H */
diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index db27b26..e09bdf9 100644
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -143,6 +143,11 @@ int nfs_readpage_async(struct nfs_open_context *ctx, struct inode *inode,

static void nfs_readpage_release(struct nfs_page *req)
{
+ struct inode *d_inode = req->wb_context->path.dentry->d_inode;
+
+ if (PageUptodate(req->wb_page))
+ nfs_readpage_to_fscache(d_inode, req->wb_page, 0);
+
unlock_page(req->wb_page);

dprintk("NFS: read done (%s/%Ld %d@%Ld)\n",