smb: client: refactor dropping cached dirs

- s/drop_cached_dir_by_name/drop_cached_dir/
  make it a generic find + invalidate function to replace
  drop_cached_dir_by_name() and cached_dir_lease_break()

We now funnel any cleanup to laundromat, so we can make the release
callback free only dirents, path, and cfid itself.

Signed-off-by: Enzo Matsumiya <ematsumiya@suse.de>

5 files changed, 29 insertions, 63 deletions

diff --git a/fs/smb/client/cached_dir.c b/fs/smb/client/cached_dir.c
index 37a9bff26da7..84ea2653cdb9 100644
--- a/fs/smb/client/cached_dir.c
+++ b/fs/smb/client/cached_dir.c
@@ -476,22 +476,6 @@ static void smb2_close_cached_fid(struct kref *ref)
 	struct cached_fid *cfid = container_of(ref, struct cached_fid, refcount);
 	struct cached_dirent *de, *q;
 
-	/*
-	 * There's no way a valid cfid can reach here.
-	 *
-	 * This is because we hould our own ref, and whenever we put it, we invalidate the cfid.
-	 *
-	 * So even if an external caller puts the last ref, cfid will already have been invalidated
-	 * by then by one of the invalidations that can happen concurrently, e.g. lease break,
-	 * invalidate_all_cached_dirs().
-	 *
-	 * So this check is mostly for precaution, but since we can still take the correct action
-	 * (just list_del()) if it's the case, do so.
-	 */
-	if (WARN_ON(cfid_is_valid(cfid)))
-		/* remaining invalidation done by drop_cfid() below */
-		list_del(&cfid->entry);
-
 	drop_cfid(cfid);
 
 	/* Delete all cached dirent names */
@@ -506,23 +490,36 @@ static void smb2_close_cached_fid(struct kref *ref)
 	kfree(cfid);
 }
 
-void drop_cached_dir_by_name(struct cached_fids *cfids, const char *name)
+bool drop_cached_dir(struct cached_fids *cfids, const void *key, int mode)
 {
 	struct cached_fid *cfid;
 
-	if (!cfids)
-		return;
+	if (!cfids || !key)
+		return false;
 
-	cfid = find_cached_dir(cfids, name, CFID_LOOKUP_PATH);
-	if (!cfid) {
-		cifs_dbg(FYI, "no cached dir found for rmdir(%s)\n", name);
-		return;
-	}
+	/*
+	 * Raw lookup here as we _must_ find any matching cfid, no matter its state.
+	 * Also, we might be racing with the SMB2 open in open_cached_dir(), so no need to wait
+	 * for it to finish.
+	 */
+	cfid = find_cfid(cfids, key, mode, false);
+	if (!cfid)
+		return false;
 
-	drop_cfid(cfid);
+	if (mode != CFID_LOOKUP_LEASEKEY) {
+		drop_cfid(cfid);
+	} else {
+		/* we're locked in smb2_is_valid_lease_break(), so can't dput/close here */
+		spin_lock(&cfids->cfid_list_lock);
+		invalidate_cfid(cfid);
+		spin_unlock(&cfids->cfid_list_lock);
+	}
 
 	/* put lookup ref */
 	kref_put(&cfid->refcount, smb2_close_cached_fid);
+	mod_delayed_work(cfid_put_wq, &cfids->laundromat_work, 0);
+
+	return true;
 }
 
 void close_cached_dir(struct cached_fid *cfid)
@@ -589,37 +586,6 @@ void invalidate_all_cached_dirs(struct cached_fids *cfids)
 	flush_delayed_work(&cfids->laundromat_work);
 }
 
-bool cached_dir_lease_break(struct cifs_tcon *tcon, __u8 lease_key[16])
-{
-	struct cached_fids *cfids = tcon->cfids;
-	struct cached_fid *cfid;
-
-	if (cfids == NULL)
-		return false;
-
-	/*
-	 * Raw lookup here as we _must_ find our lease, no matter cfid state.
-	 * Also, this lease break might be coming from the SMB2 open in open_cached_dir(), so no
-	 * need to wait for it to finish.
-	 */
-	cfid = find_cfid(cfids, lease_key, CFID_LOOKUP_LEASEKEY, false);
-	if (cfid) {
-		/* found a lease, invalidate cfid and schedule immediate cleanup on laundromat */
-		spin_lock(&cfids->cfid_list_lock);
-		invalidate_cfid(cfid);
-		cfid->has_lease = false;
-		spin_unlock(&cfids->cfid_list_lock);
-
-		/* put lookup ref */
-		kref_put(&cfid->refcount, smb2_close_cached_fid);
-		mod_delayed_work(cfid_put_wq, &cfids->laundromat_work, 0);
-
-		return true;
-	}
-
-	return false;
-}
-
 static struct cached_fid *init_cached_dir(const char *path)
 {
 	struct cached_fid *cfid;
diff --git a/fs/smb/client/cached_dir.h b/fs/smb/client/cached_dir.h
index afb9af227219..bed5ba68b07f 100644
--- a/fs/smb/client/cached_dir.h
+++ b/fs/smb/client/cached_dir.h
@@ -82,8 +82,7 @@ extern struct cached_fid *find_cached_dir(struct cached_fids *cfids, const void
 extern int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon, const char *path,
 			   struct cifs_sb_info *cifs_sb, struct cached_fid **cfid);
 extern void close_cached_dir(struct cached_fid *cfid);
-extern void drop_cached_dir_by_name(struct cached_fids *cfids, const char *name);
+extern bool drop_cached_dir(struct cached_fids *cfids, const void *key, int mode);
 extern void close_all_cached_dirs(struct cifs_sb_info *cifs_sb);
 extern void invalidate_all_cached_dirs(struct cached_fids *cfids);
-extern bool cached_dir_lease_break(struct cifs_tcon *tcon, __u8 lease_key[16]);
 #endif			/* _CACHED_DIR_H */
diff --git a/fs/smb/client/inode.c b/fs/smb/client/inode.c
index df236c844611..f2eff1138ed0 100644
--- a/fs/smb/client/inode.c
+++ b/fs/smb/client/inode.c
@@ -2615,7 +2615,7 @@ unlink_target:
 			 * ->i_nlink and then mark it as delete pending.
 			 */
 			if (S_ISDIR(inode->i_mode)) {
-				drop_cached_dir_by_name(tcon->cfids, to_name);
+				drop_cached_dir(tcon->cfids, to_name, CFID_LOOKUP_PATH);
 				spin_lock(&inode->i_lock);
 				i_size_write(inode, 0);
 				clear_nlink(inode);
diff --git a/fs/smb/client/smb2inode.c b/fs/smb/client/smb2inode.c
index c76fe1dec390..62d6adf50ad1 100644
--- a/fs/smb/client/smb2inode.c
+++ b/fs/smb/client/smb2inode.c
@@ -1160,7 +1160,7 @@ smb2_rmdir(const unsigned int xid, struct cifs_tcon *tcon, const char *name,
 {
 	struct cifs_open_parms oparms;
 
-	drop_cached_dir_by_name(tcon->cfids, name);
+	drop_cached_dir(tcon->cfids, name, CFID_LOOKUP_PATH);
 	oparms = CIFS_OPARMS(cifs_sb, tcon, name, DELETE,
 			     FILE_OPEN, CREATE_NOT_FILE, ACL_NO_MODE);
 	return smb2_compound_op(xid, tcon, cifs_sb,
@@ -1238,7 +1238,7 @@ int smb2_rename_path(const unsigned int xid,
 	struct cifsFileInfo *cfile;
 	__u32 co = file_create_options(source_dentry);
 
-	drop_cached_dir_by_name(tcon->cfids, from_name);
+	drop_cached_dir(tcon->cfids, from_name, CFID_LOOKUP_PATH);
 	cifs_get_writable_path(tcon, from_name, FIND_WR_WITH_DELETE, &cfile);
 
 	int rc = smb2_set_path_attr(xid, tcon, from_name, to_name, cifs_sb,
@@ -1520,7 +1520,8 @@ int smb2_rename_pending_delete(const char *full_path,
 		goto out;
 	}
 
-	drop_cached_dir_by_name(tcon->cfids, full_path);
+	drop_cached_dir(tcon->cfids, full_path, CFID_LOOKUP_PATH);
+
 	oparms = CIFS_OPARMS(cifs_sb, tcon, full_path,
 			     DELETE | FILE_WRITE_ATTRIBUTES,
 			     FILE_OPEN, co, ACL_NO_MODE);
diff --git a/fs/smb/client/smb2misc.c b/fs/smb/client/smb2misc.c
index 89d933b4a8bc..71d987f76a12 100644
--- a/fs/smb/client/smb2misc.c
+++ b/fs/smb/client/smb2misc.c
@@ -660,7 +660,7 @@ smb2_is_valid_lease_break(char *buffer, struct TCP_Server_Info *server)
 			}
 			spin_unlock(&tcon->open_file_lock);
 
-			if (cached_dir_lease_break(tcon, rsp->LeaseKey)) {
+			if (drop_cached_dir(tcon->cfids, rsp->LeaseKey, CFID_LOOKUP_LEASEKEY)) {
 				spin_unlock(&cifs_tcp_ses_lock);
 				return true;
 			}