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.or... 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 --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; }
/**