[PATCH 29/37] NFS: Invalidate FsCache page flags when cache removed

David Howells
2008-02-08T17:15:56Z

Invalidate the FsCache page flags on the pages belonging to an inode when the
cache backing that NFS inode is removed.

This allows a live cache to be withdrawn.

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

fs/nfs/fscache-index.c | 40 ++++++++++++++++++++++++++++++++++++++++
1 files changed, 40 insertions(+), 0 deletions(-)

diff --git a/fs/nfs/fscache-index.c b/fs/nfs/fscache-index.c
index c3c63fa..eec8e7e 100644
--- a/fs/nfs/fscache-index.c
+++ b/fs/nfs/fscache-index.c
@@ -246,6 +246,45 @@ static enum fscache_checkaux nfs_cache_inode_check_aux(void *cookie_netfs_data,
}

/*
+ * Indication from FS-Cache that the cookie is no longer cached
+ * - This function is called when the backing store currently caching a cookie
+ * is removed
+ * - The netfs should use this to clean up any markers indicating cached pages
+ * - This is mandatory for any object that may have data
+ */
+static void nfs_cache_inode_now_uncached(void *cookie_netfs_data)
+{
+ struct nfs_inode *nfsi = cookie_netfs_data;
+ struct pagevec pvec;
+ pgoff_t first;
+ int loop, nr_pages;
+
+ pagevec_init(&pvec, 0);
+ first = 0;
+
+ dprintk("NFS: nfs_inode_now_uncached: nfs_inode 0x%p\n", nfsi);
+
+ for (;;) {
+ /* grab a bunch of pages to unmark */
+ nr_pages = pagevec_lookup(&pvec,
+ nfsi->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();
+ }
+}
+
+/*
* Define the inode object for FS-Cache. This is used to describe an inode
* object to fscache_acquire_cookie(). It is keyed by the NFS file handle for
* an inode.
@@ -261,4 +300,5 @@ const struct fscache_cookie_def nfs_cache_inode_object_def = {
.get_attr = nfs_cache_inode_get_attr,
.get_aux = nfs_cache_inode_get_aux,
.check_aux = nfs_cache_inode_check_aux,
+ .now_uncached = nfs_cache_inode_now_uncached,
};