Merge tag 'fscache-next-20180406' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

Pull fscache updates from David Howells:
 "Three patches that fix some of AFS's usage of fscache:

   (1) Need to invalidate the cache if a foreign data change is detected
       on the server.

   (2) Move the vnode ID uniquifier (equivalent to i_generation) from
       the auxiliary data to the index key to prevent a race between
       file delete and a subsequent file create seeing the same index
       key.

   (3) Need to retire cookies that correspond to files that we think got
       deleted on the server.

  Four patches to fix some things in fscache and cachefiles:

   (4) Fix a couple of checker warnings.

   (5) Correctly indicate to the end-of-operation callback whether an
       operation completed or was cancelled.

   (6) Add a check for multiple cookie relinquishment.

   (7) Fix a path through the asynchronous write that doesn't wake up a
       waiter for a page if the cache decides not to write that page,
       but discards it instead.

  A couple of patches to add tracepoints to fscache and cachefiles:

   (8) Add tracepoints for cookie operators, object state machine
       execution, cachefiles object management and cachefiles VFS
       operations.

   (9) Add tracepoints for fscache operation management and page
       wrangling.

  And then three development patches:

  (10) Attach the index key and auxiliary data to the cookie, pass this
       information through various fscache-netfs API functions and get
       rid of the callbacks to the netfs to get it.

       This means that the cache can get at this information, even if
       the netfs goes away. It also means that the cache can be lazy in
       updating the coherency data.

  (11) Pass the object data size through various fscache-netfs API
       rather than calling back to the netfs for it, and store the value
       in the object.

       This makes it easier to correctly resize the object, as the size
       is updated on writes to the cache, rather than calling back out
       to the netfs.

  (12) Maintain a catalogue of allocated cookies. This makes it possible
       to catch cookie collision up front rather than down in the bowels
       of the cache being run from a service thread from the object
       state machine.

       This will also make it possible in the future to reconnect to a
       cookie that's not gone dead yet because it's waiting for
       finalisation of the storage and also make it possible to bring
       cookies online if the cache is added after the cookie has been
       obtained"

* tag 'fscache-next-20180406' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
  fscache: Maintain a catalogue of allocated cookies
  fscache: Pass object size in rather than calling back for it
  fscache: Attach the index key and aux data to the cookie
  fscache: Add more tracepoints
  fscache: Add tracepoints
  fscache: Fix hanging wait on page discarded by writeback
  fscache: Detect multiple relinquishment of a cookie
  fscache: Pass the correct cancelled indications to fscache_op_complete()
  fscache, cachefiles: Fix checker warnings
  afs: Be more aggressive in retiring cached vnodes
  afs: Use the vnode ID uniquifier in the cache key not the aux data
  afs: Invalidate cache on server data change

1 files changed, 33 insertions, 67 deletions

diff --git a/fs/9p/cache.c b/fs/9p/cache.c
index 64c58eb26159..9eb34701a566 100644
--- a/fs/9p/cache.c
+++ b/fs/9p/cache.c
@@ -55,42 +55,27 @@ int v9fs_random_cachetag(struct v9fs_session_info *v9ses)
 	return scnprintf(v9ses->cachetag, CACHETAG_LEN, "%lu", jiffies);
 }
 
-static uint16_t v9fs_cache_session_get_key(const void *cookie_netfs_data,
-					   void *buffer, uint16_t bufmax)
-{
-	struct v9fs_session_info *v9ses;
-	uint16_t klen = 0;
-
-	v9ses = (struct v9fs_session_info *)cookie_netfs_data;
-	p9_debug(P9_DEBUG_FSC, "session %p buf %p size %u\n",
-		 v9ses, buffer, bufmax);
-
-	if (v9ses->cachetag)
-		klen = strlen(v9ses->cachetag);
-
-	if (klen > bufmax)
-		return 0;
-
-	memcpy(buffer, v9ses->cachetag, klen);
-	p9_debug(P9_DEBUG_FSC, "cache session tag %s\n", v9ses->cachetag);
-	return klen;
-}
-
 const struct fscache_cookie_def v9fs_cache_session_index_def = {
 	.name		= "9P.session",
 	.type		= FSCACHE_COOKIE_TYPE_INDEX,
-	.get_key	= v9fs_cache_session_get_key,
 };
 
 void v9fs_cache_session_get_cookie(struct v9fs_session_info *v9ses)
 {
 	/* If no cache session tag was specified, we generate a random one. */
-	if (!v9ses->cachetag)
-		v9fs_random_cachetag(v9ses);
+	if (!v9ses->cachetag) {
+		if (v9fs_random_cachetag(v9ses) < 0) {
+			v9ses->fscache = NULL;
+			return;
+		}
+	}
 
 	v9ses->fscache = fscache_acquire_cookie(v9fs_cache_netfs.primary_index,
 						&v9fs_cache_session_index_def,
-						v9ses, true);
+						v9ses->cachetag,
+						strlen(v9ses->cachetag),
+						NULL, 0,
+						v9ses, 0, true);
 	p9_debug(P9_DEBUG_FSC, "session %p get cookie %p\n",
 		 v9ses, v9ses->fscache);
 }
@@ -99,45 +84,15 @@ void v9fs_cache_session_put_cookie(struct v9fs_session_info *v9ses)
 {
 	p9_debug(P9_DEBUG_FSC, "session %p put cookie %p\n",
 		 v9ses, v9ses->fscache);
-	fscache_relinquish_cookie(v9ses->fscache, 0);
+	fscache_relinquish_cookie(v9ses->fscache, NULL, false);
 	v9ses->fscache = NULL;
 }
 
-
-static uint16_t v9fs_cache_inode_get_key(const void *cookie_netfs_data,
-					 void *buffer, uint16_t bufmax)
-{
-	const struct v9fs_inode *v9inode = cookie_netfs_data;
-	memcpy(buffer, &v9inode->qid.path, sizeof(v9inode->qid.path));
-	p9_debug(P9_DEBUG_FSC, "inode %p get key %llu\n",
-		 &v9inode->vfs_inode, v9inode->qid.path);
-	return sizeof(v9inode->qid.path);
-}
-
-static void v9fs_cache_inode_get_attr(const void *cookie_netfs_data,
-				      uint64_t *size)
-{
-	const struct v9fs_inode *v9inode = cookie_netfs_data;
-	*size = i_size_read(&v9inode->vfs_inode);
-
-	p9_debug(P9_DEBUG_FSC, "inode %p get attr %llu\n",
-		 &v9inode->vfs_inode, *size);
-}
-
-static uint16_t v9fs_cache_inode_get_aux(const void *cookie_netfs_data,
-					 void *buffer, uint16_t buflen)
-{
-	const struct v9fs_inode *v9inode = cookie_netfs_data;
-	memcpy(buffer, &v9inode->qid.version, sizeof(v9inode->qid.version));
-	p9_debug(P9_DEBUG_FSC, "inode %p get aux %u\n",
-		 &v9inode->vfs_inode, v9inode->qid.version);
-	return sizeof(v9inode->qid.version);
-}
-
 static enum
 fscache_checkaux v9fs_cache_inode_check_aux(void *cookie_netfs_data,
 					    const void *buffer,
-					    uint16_t buflen)
+					    uint16_t buflen,
+					    loff_t object_size)
 {
 	const struct v9fs_inode *v9inode = cookie_netfs_data;
 
@@ -154,9 +109,6 @@ fscache_checkaux v9fs_cache_inode_check_aux(void *cookie_netfs_data,
 const struct fscache_cookie_def v9fs_cache_inode_index_def = {
 	.name		= "9p.inode",
 	.type		= FSCACHE_COOKIE_TYPE_DATAFILE,
-	.get_key	= v9fs_cache_inode_get_key,
-	.get_attr	= v9fs_cache_inode_get_attr,
-	.get_aux	= v9fs_cache_inode_get_aux,
 	.check_aux	= v9fs_cache_inode_check_aux,
 };
 
@@ -175,7 +127,13 @@ void v9fs_cache_inode_get_cookie(struct inode *inode)
 	v9ses = v9fs_inode2v9ses(inode);
 	v9inode->fscache = fscache_acquire_cookie(v9ses->fscache,
 						  &v9fs_cache_inode_index_def,
-						  v9inode, true);
+						  &v9inode->qid.path,
+						  sizeof(v9inode->qid.path),
+						  &v9inode->qid.version,
+						  sizeof(v9inode->qid.version),
+						  v9inode,
+						  i_size_read(&v9inode->vfs_inode),
+						  true);
 
 	p9_debug(P9_DEBUG_FSC, "inode %p get cookie %p\n",
 		 inode, v9inode->fscache);
@@ -190,7 +148,8 @@ void v9fs_cache_inode_put_cookie(struct inode *inode)
 	p9_debug(P9_DEBUG_FSC, "inode %p put cookie %p\n",
 		 inode, v9inode->fscache);
 
-	fscache_relinquish_cookie(v9inode->fscache, 0);
+	fscache_relinquish_cookie(v9inode->fscache, &v9inode->qid.version,
+				  false);
 	v9inode->fscache = NULL;
 }
 
@@ -203,7 +162,7 @@ void v9fs_cache_inode_flush_cookie(struct inode *inode)
 	p9_debug(P9_DEBUG_FSC, "inode %p flush cookie %p\n",
 		 inode, v9inode->fscache);
 
-	fscache_relinquish_cookie(v9inode->fscache, 1);
+	fscache_relinquish_cookie(v9inode->fscache, NULL, true);
 	v9inode->fscache = NULL;
 }
 
@@ -236,12 +195,18 @@ void v9fs_cache_inode_reset_cookie(struct inode *inode)
 	old = v9inode->fscache;
 
 	mutex_lock(&v9inode->fscache_lock);
-	fscache_relinquish_cookie(v9inode->fscache, 1);
+	fscache_relinquish_cookie(v9inode->fscache, NULL, true);
 
 	v9ses = v9fs_inode2v9ses(inode);
 	v9inode->fscache = fscache_acquire_cookie(v9ses->fscache,
 						  &v9fs_cache_inode_index_def,
-						  v9inode, true);
+						  &v9inode->qid.path,
+						  sizeof(v9inode->qid.path),
+						  &v9inode->qid.version,
+						  sizeof(v9inode->qid.version),
+						  v9inode,
+						  i_size_read(&v9inode->vfs_inode),
+						  true);
 	p9_debug(P9_DEBUG_FSC, "inode %p revalidating cookie old %p new %p\n",
 		 inode, old, v9inode->fscache);
 
@@ -367,7 +332,8 @@ void __v9fs_readpage_to_fscache(struct inode *inode, struct page *page)
 	const struct v9fs_inode *v9inode = V9FS_I(inode);
 
 	p9_debug(P9_DEBUG_FSC, "inode %p page %p\n", inode, page);
-	ret = fscache_write_page(v9inode->fscache, page, GFP_KERNEL);
+	ret = fscache_write_page(v9inode->fscache, page,
+				 i_size_read(&v9inode->vfs_inode), GFP_KERNEL);
 	p9_debug(P9_DEBUG_FSC, "ret =  %d\n", ret);
 	if (ret != 0)
 		v9fs_uncache_page(inode, page);