cifs: read pages from FS-Cache
Read pages from a FS-Cache data storage object into a CIFS inode.
Signed-off-by: Suresh Jayaraman <sjayaraman@suse.de>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index ff726c8..fa04a00d 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -1977,6 +1977,15 @@
cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
pTcon = cifs_sb->tcon;
+ /*
+ * Reads as many pages as possible from fscache. Returns -ENOBUFS
+ * immediately if the cookie is negative
+ */
+ rc = cifs_readpages_from_fscache(mapping->host, mapping, page_list,
+ &num_pages);
+ if (rc == 0)
+ goto read_complete;
+
cFYI(DBG2, "rpages: num pages %d", num_pages);
for (i = 0; i < num_pages; ) {
unsigned contig_pages;
@@ -2087,6 +2096,7 @@
smb_read_data = NULL;
}
+read_complete:
FreeXid(xid);
return rc;
}
@@ -2097,6 +2107,11 @@
char *read_data;
int rc;
+ /* Is the page cached? */
+ rc = cifs_readpage_from_fscache(file->f_path.dentry->d_inode, page);
+ if (rc == 0)
+ goto read_complete;
+
page_cache_get(page);
read_data = kmap(page);
/* for reads over a certain size could initiate async read ahead */
@@ -2125,6 +2140,8 @@
io_error:
kunmap(page);
page_cache_release(page);
+
+read_complete:
return rc;
}
diff --git a/fs/cifs/fscache.c b/fs/cifs/fscache.c
index 3b16367..9f3f5c4 100644
--- a/fs/cifs/fscache.c
+++ b/fs/cifs/fscache.c
@@ -140,6 +140,79 @@
return 1;
}
+static void cifs_readpage_from_fscache_complete(struct page *page, void *ctx,
+ int error)
+{
+ cFYI(1, "CFS: readpage_from_fscache_complete (0x%p/%d)",
+ page, error);
+ if (!error)
+ SetPageUptodate(page);
+ unlock_page(page);
+}
+
+/*
+ * Retrieve a page from FS-Cache
+ */
+int __cifs_readpage_from_fscache(struct inode *inode, struct page *page)
+{
+ int ret;
+
+ cFYI(1, "CIFS: readpage_from_fscache(fsc:%p, p:%p, i:0x%p",
+ CIFS_I(inode)->fscache, page, inode);
+ ret = fscache_read_or_alloc_page(CIFS_I(inode)->fscache, page,
+ cifs_readpage_from_fscache_complete,
+ NULL,
+ GFP_KERNEL);
+ switch (ret) {
+
+ case 0: /* page found in fscache, read submitted */
+ cFYI(1, "CIFS: readpage_from_fscache: submitted");
+ return ret;
+ case -ENOBUFS: /* page won't be cached */
+ case -ENODATA: /* page not in cache */
+ cFYI(1, "CIFS: readpage_from_fscache %d", ret);
+ return 1;
+
+ default:
+ cERROR(1, "unknown error ret = %d", ret);
+ }
+ return ret;
+}
+
+/*
+ * Retrieve a set of pages from FS-Cache
+ */
+int __cifs_readpages_from_fscache(struct inode *inode,
+ struct address_space *mapping,
+ struct list_head *pages,
+ unsigned *nr_pages)
+{
+ int ret;
+
+ cFYI(1, "CIFS: __cifs_readpages_from_fscache (0x%p/%u/0x%p)",
+ CIFS_I(inode)->fscache, *nr_pages, inode);
+ ret = fscache_read_or_alloc_pages(CIFS_I(inode)->fscache, mapping,
+ pages, nr_pages,
+ cifs_readpage_from_fscache_complete,
+ NULL,
+ mapping_gfp_mask(mapping));
+ switch (ret) {
+ case 0: /* read submitted to the cache for all pages */
+ cFYI(1, "CIFS: readpages_from_fscache: submitted");
+ return ret;
+
+ case -ENOBUFS: /* some pages are not cached and can't be */
+ case -ENODATA: /* some pages are not cached */
+ cFYI(1, "CIFS: readpages_from_fscache: no page");
+ return 1;
+
+ default:
+ cFYI(1, "unknown error ret = %d", ret);
+ }
+
+ return ret;
+}
+
void __cifs_readpage_to_fscache(struct inode *inode, struct page *page)
{
int ret;
diff --git a/fs/cifs/fscache.h b/fs/cifs/fscache.h
index 1a00d70..79164c6 100644
--- a/fs/cifs/fscache.h
+++ b/fs/cifs/fscache.h
@@ -32,7 +32,6 @@
extern const struct fscache_cookie_def cifs_fscache_super_index_def;
extern const struct fscache_cookie_def cifs_fscache_inode_object_def;
-
extern int cifs_fscache_register(void);
extern void cifs_fscache_unregister(void);
@@ -50,6 +49,11 @@
extern void __cifs_fscache_invalidate_page(struct page *, struct inode *);
extern int cifs_fscache_release_page(struct page *page, gfp_t gfp);
+extern int __cifs_readpage_from_fscache(struct inode *, struct page *);
+extern int __cifs_readpages_from_fscache(struct inode *,
+ struct address_space *,
+ struct list_head *,
+ unsigned *);
extern void __cifs_readpage_to_fscache(struct inode *, struct page *);
@@ -60,6 +64,26 @@
__cifs_fscache_invalidate_page(page, inode);
}
+static inline int cifs_readpage_from_fscache(struct inode *inode,
+ struct page *page)
+{
+ if (CIFS_I(inode)->fscache)
+ return __cifs_readpage_from_fscache(inode, page);
+
+ return -ENOBUFS;
+}
+
+static inline int cifs_readpages_from_fscache(struct inode *inode,
+ struct address_space *mapping,
+ struct list_head *pages,
+ unsigned *nr_pages)
+{
+ if (CIFS_I(inode)->fscache)
+ return __cifs_readpages_from_fscache(inode, mapping, pages,
+ nr_pages);
+ return -ENOBUFS;
+}
+
static inline void cifs_readpage_to_fscache(struct inode *inode,
struct page *page)
{
@@ -90,6 +114,20 @@
static inline int cifs_fscache_invalidate_page(struct page *page,
struct inode *) {}
+static inline int
+cifs_readpage_from_fscache(struct inode *inode, struct page *page)
+{
+ return -ENOBUFS;
+}
+
+static inline int cifs_readpages_from_fscache(struct inode *inode,
+ struct address_space *mapping,
+ struct list_head *pages,
+ unsigned *nr_pages)
+{
+ return -ENOBUFS;
+}
+
static inline void cifs_readpage_to_fscache(struct inode *inode,
struct page *page) {}