From: Kees Cook <keescook@chromium.org>
Date: Fri, 18 Nov 2011 21:49:00 +0000 (-0800)
Subject: pstore: gracefully handle NULL pstore_info functions
X-Git-Tag: v3.3-rc1~178^2
X-Git-Url: http://git.samba.org/samba.git/?p=sfrench%2Fcifs-2.6.git;a=commitdiff_plain;h=2174f6df7891fa331800beb72634c969f017900b

pstore: gracefully handle NULL pstore_info functions

If a pstore backend doesn't want to support various portions of the
pstore interface, it can just leave those functions NULL instead of
creating no-op stubs.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
---

diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c
index 379a02dc1217..b3b426edb2fd 100644
--- a/fs/pstore/inode.c
+++ b/fs/pstore/inode.c
@@ -80,7 +80,8 @@ static int pstore_unlink(struct inode *dir, struct dentry *dentry)
 {
 	struct pstore_private *p = dentry->d_inode->i_private;
 
-	p->psi->erase(p->type, p->id, p->psi);
+	if (p->psi->erase)
+		p->psi->erase(p->type, p->id, p->psi);
 
 	return simple_unlink(dir, dentry);
 }
diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index f146d89179bf..9ec22d3b4293 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -207,8 +207,7 @@ void pstore_get_records(int quiet)
 		return;
 
 	mutex_lock(&psi->read_mutex);
-	rc = psi->open(psi);
-	if (rc)
+	if (psi->open && psi->open(psi))
 		goto out;
 
 	while ((size = psi->read(&id, &type, &time, &buf, psi)) > 0) {
@@ -219,7 +218,8 @@ void pstore_get_records(int quiet)
 		if (rc && (rc != -EEXIST || !quiet))
 			failed++;
 	}
-	psi->close(psi);
+	if (psi->close)
+		psi->close(psi);
 out:
 	mutex_unlock(&psi->read_mutex);