cifs: FS-Cache page management

Takes care of invalidation and release of FS-Cache marked pages and also
invalidation of the FsCache page flag when the inode is removed.

Signed-off-by: Suresh Jayaraman <sjayaraman@suse.de>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

4 files changed, 93 insertions, 0 deletions

diff --git a/fs/cifs/cache.c b/fs/cifs/cache.c
index b2649cfd3a04..224d7bbd1fcc 100644
--- a/fs/cifs/cache.c
+++ b/fs/cifs/cache.c
@@ -290,6 +290,36 @@ fscache_checkaux cifs_fscache_inode_check_aux(void *cookie_netfs_data,
         return FSCACHE_CHECKAUX_OKAY;
 }
 
+static void cifs_fscache_inode_now_uncached(void *cookie_netfs_data)
+{
+        struct cifsInodeInfo *cifsi = cookie_netfs_data;
+        struct pagevec pvec;
+        pgoff_t first;
+        int loop, nr_pages;
+
+        pagevec_init(&pvec, 0);
+        first = 0;
+
+        cFYI(1, "cifs inode 0x%p now uncached", cifsi);
+
+        for (;;) {
+                nr_pages = pagevec_lookup(&pvec,
+                                          cifsi->vfs_inode.i_mapping, first,
+                                          PAGEVEC_SIZE - pagevec_count(&pvec));
+                if (!nr_pages)
+                        break;
+
+                for (loop = 0; loop < nr_pages; loop++)
+                        ClearPageFsCache(pvec.pages[loop]);
+
+                first = pvec.pages[nr_pages - 1]->index + 1;
+
+                pvec.nr = nr_pages;
+                pagevec_release(&pvec);
+                cond_resched();
+        }
+}
+
 const struct fscache_cookie_def cifs_fscache_inode_object_def = {
         .name           = "CIFS.uniqueid",
         .type           = FSCACHE_COOKIE_TYPE_DATAFILE,
@@ -297,4 +327,5 @@ const struct fscache_cookie_def cifs_fscache_inode_object_def = {
         .get_attr       = cifs_fscache_inode_get_attr,
         .get_aux        = cifs_fscache_inode_get_aux,
         .check_aux      = cifs_fscache_inode_check_aux,
+        .now_uncached   = cifs_fscache_inode_now_uncached,
 };
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index d302d941f9ac..f677ede766d1 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -2267,6 +2267,22 @@ out:
         return rc;
 }
 
+static int cifs_release_page(struct page *page, gfp_t gfp)
+{
+        if (PagePrivate(page))
+                return 0;
+
+        return cifs_fscache_release_page(page, gfp);
+}
+
+static void cifs_invalidate_page(struct page *page, unsigned long offset)
+{
+        struct cifsInodeInfo *cifsi = CIFS_I(page->mapping->host);
+
+        if (offset == 0)
+                cifs_fscache_invalidate_page(page, &cifsi->vfs_inode);
+}
+
 static void
 cifs_oplock_break(struct slow_work *work)
 {
@@ -2340,6 +2356,8 @@ const struct address_space_operations cifs_addr_ops = {
         .write_begin = cifs_write_begin,
         .write_end = cifs_write_end,
         .set_page_dirty = __set_page_dirty_nobuffers,
+        .releasepage = cifs_release_page,
+        .invalidatepage = cifs_invalidate_page,
         /* .sync_page = cifs_sync_page, */
         /* .direct_IO = */
 };
@@ -2356,6 +2374,8 @@ const struct address_space_operations cifs_addr_ops_smallbuf = {
         .write_begin = cifs_write_begin,
         .write_end = cifs_write_end,
         .set_page_dirty = __set_page_dirty_nobuffers,
+        .releasepage = cifs_release_page,
+        .invalidatepage = cifs_invalidate_page,
         /* .sync_page = cifs_sync_page, */
         /* .direct_IO = */
 };
diff --git a/fs/cifs/fscache.c b/fs/cifs/fscache.c
index 6c8d96758ddb..5dd935280049 100644
--- a/fs/cifs/fscache.c
+++ b/fs/cifs/fscache.c
@@ -124,3 +124,29 @@ void cifs_fscache_reset_inode_cookie(struct inode *inode)
                                 cifsi->fscache, old);
         }
 }
+
+int cifs_fscache_release_page(struct page *page, gfp_t gfp)
+{
+        if (PageFsCache(page)) {
+                struct inode *inode = page->mapping->host;
+                struct cifsInodeInfo *cifsi = CIFS_I(inode);
+
+                cFYI(1, "CIFS: fscache release page (0x%p/0x%p)",
+                                page, cifsi->fscache);
+                if (!fscache_maybe_release_page(cifsi->fscache, page, gfp))
+                        return 0;
+        }
+
+        return 1;
+}
+
+void __cifs_fscache_invalidate_page(struct page *page, struct inode *inode)
+{
+        struct cifsInodeInfo *cifsi = CIFS_I(inode);
+        struct fscache_cookie *cookie = cifsi->fscache;
+
+        cFYI(1, "CIFS: fscache invalidatepage (0x%p/0x%p)", page, cookie);
+        fscache_wait_on_page_write(cookie, page);
+        fscache_uncache_page(cookie, page);
+}
+
diff --git a/fs/cifs/fscache.h b/fs/cifs/fscache.h
index 1008f4050835..5e18a21eee9d 100644
--- a/fs/cifs/fscache.h
+++ b/fs/cifs/fscache.h
@@ -48,6 +48,16 @@ extern void cifs_fscache_release_inode_cookie(struct inode *);
 extern void cifs_fscache_set_inode_cookie(struct inode *, struct file *);
 extern void cifs_fscache_reset_inode_cookie(struct inode *);
 
+extern void __cifs_fscache_invalidate_page(struct page *, struct inode *);
+extern int cifs_fscache_release_page(struct page *page, gfp_t gfp);
+
+static inline void cifs_fscache_invalidate_page(struct page *page,
+                                               struct inode *inode)
+{
+        if (PageFsCache(page))
+                __cifs_fscache_invalidate_page(page, inode);
+}
+
 #else /* CONFIG_CIFS_FSCACHE */
 static inline int cifs_fscache_register(void) { return 0; }
 static inline void cifs_fscache_unregister(void) {}
@@ -64,7 +74,13 @@ static inline void cifs_fscache_release_inode_cookie(struct inode *inode) {}
 static inline void cifs_fscache_set_inode_cookie(struct inode *inode,
                                                  struct file *filp) {}
 static inline void cifs_fscache_reset_inode_cookie(struct inode *inode) {}
+static inline void cifs_fscache_release_page(struct page *page, gfp_t gfp)
+{
+        return 1; /* May release page */
+}
 
+static inline int cifs_fscache_invalidate_page(struct page *page,
+                        struct inode *) {}
 
 #endif /* CONFIG_CIFS_FSCACHE */