Merge patch series "fscache/cachefiles: Some bugfixes"

Zizhi Wo <[email protected]> says:

This patchset mainly includes 5 fix patches about fscache/cachefiles.
The first patch fixes an issue with the incorrect return length, and the
fourth patch addresses a null pointer dereference issue with file.

* patches from https://lore.kernel.org/r/[email protected]:
  netfs/fscache: Add a memory barrier for FSCACHE_VOLUME_CREATING
  cachefiles: Fix NULL pointer dereference in object->file
  cachefiles: Clean up in cachefiles_commit_tmpfile()
  cachefiles: Fix missing pos updates in cachefiles_ondemand_fd_write_iter()
  cachefiles: Fix incorrect length return value in cachefiles_ondemand_fd_write_iter()

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Christian Brauner <[email protected]>

1 files changed, 10 insertions, 4 deletions

diff --git a/fs/cachefiles/interface.c b/fs/cachefiles/interface.c
index 35ba2117a6f6..3e63cfe15874 100644
--- a/fs/cachefiles/interface.c
+++ b/fs/cachefiles/interface.c
@@ -327,6 +327,8 @@ static void cachefiles_commit_object(struct cachefiles_object *object,
 static void cachefiles_clean_up_object(struct cachefiles_object *object,
 				       struct cachefiles_cache *cache)
 {
+	struct file *file;
+
 	if (test_bit(FSCACHE_COOKIE_RETIRED, &object->cookie->flags)) {
 		if (!test_bit(CACHEFILES_OBJECT_USING_TMPFILE, &object->flags)) {
 			cachefiles_see_object(object, cachefiles_obj_see_clean_delete);
@@ -342,10 +344,14 @@ static void cachefiles_clean_up_object(struct cachefiles_object *object,
 	}
 
 	cachefiles_unmark_inode_in_use(object, object->file);
-	if (object->file) {
-		fput(object->file);
-		object->file = NULL;
-	}
+
+	spin_lock(&object->lock);
+	file = object->file;
+	object->file = NULL;
+	spin_unlock(&object->lock);
+
+	if (file)
+		fput(file);
 }
 
 /*