diff mbox series

[v6.6,25/57] eventfs: Do not invalidate dentry in create_file/dir_dentry()

Message ID 20240206120950.446963304@rostedt.homelinux.com
State New
Headers
Series eventfs: Linus's updates for 6.6 |

Commit Message

Steven Rostedt Feb. 6, 2024, 12:09 p.m. UTC 
  From: "Steven Rostedt (Google)" <rostedt@goodmis.org>

With the call to simple_recursive_removal() on the entire eventfs sub
system when the directory is removed, it performs the d_invalidate on all
the dentries when it is removed. There's no need to do clean ups when a
dentry is being created while the directory is being deleted.

As dentries are cleaned up by the simpler_recursive_removal(), trying to
do d_invalidate() in these functions will cause the dentry to be
invalidated twice, and crash the kernel.

Link: https://lore.kernel.org/all/20231116123016.140576-1-naresh.kamboju@linaro.org/
Link: https://lkml.kernel.org/r/20231120235154.422970988@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Fixes: 407c6726ca71 ("eventfs: Use simple_recursive_removal() to clean up dentries")
Reported-by: Mark Rutland <mark.rutland@arm.com>
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
(cherry picked from commit 71cade82f2b553a74d046c015c986f2df165696f)
---
 fs/tracefs/event_inode.c | 19 ++++++-------------
 1 file changed, 6 insertions(+), 13 deletions(-)
diff mbox series

Patch

diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c
index f239b2b507a4..3eb6c622a74d 100644
--- a/fs/tracefs/event_inode.c
+++ b/fs/tracefs/event_inode.c
@@ -326,7 +326,6 @@  create_file_dentry(struct eventfs_inode *ei, int idx,
 	struct eventfs_attr *attr = NULL;
 	struct dentry **e_dentry = &ei->d_children[idx];
 	struct dentry *dentry;
-	bool invalidate = false;
 
 	mutex_lock(&eventfs_mutex);
 	if (ei->is_freed) {
@@ -389,17 +388,14 @@  create_file_dentry(struct eventfs_inode *ei, int idx,
 		 * Otherwise it means two dentries exist with the same name.
 		 */
 		WARN_ON_ONCE(!ei->is_freed);
-		invalidate = true;
+		dentry = NULL;
 	}
 	mutex_unlock(&eventfs_mutex);
 
-	if (invalidate)
-		d_invalidate(dentry);
-
-	if (lookup || invalidate)
+	if (lookup)
 		dput(dentry);
 
-	return invalidate ? NULL : dentry;
+	return dentry;
 }
 
 /**
@@ -439,7 +435,6 @@  static struct dentry *
 create_dir_dentry(struct eventfs_inode *pei, struct eventfs_inode *ei,
 		  struct dentry *parent, bool lookup)
 {
-	bool invalidate = false;
 	struct dentry *dentry = NULL;
 
 	mutex_lock(&eventfs_mutex);
@@ -495,16 +490,14 @@  create_dir_dentry(struct eventfs_inode *pei, struct eventfs_inode *ei,
 		 * Otherwise it means two dentries exist with the same name.
 		 */
 		WARN_ON_ONCE(!ei->is_freed);
-		invalidate = true;
+		dentry = NULL;
 	}
 	mutex_unlock(&eventfs_mutex);
-	if (invalidate)
-		d_invalidate(dentry);
 
-	if (lookup || invalidate)
+	if (lookup)
 		dput(dentry);
 
-	return invalidate ? NULL : dentry;
+	return dentry;
 }
 
 /**