This is a note to let you know that I've just added the patch titled eventfs: Do not invalidate dentry in create_file/dir_dentry() to the 6.6-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: eventfs-do-not-invalidate-dentry-in-create_file-dir_dentry.patch and it can be found in the queue-6.6 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From SRS0=eEWY=JP=rostedt.homelinux.com=rostedt@xxxxxxxxxx Tue Feb 6 13:10:46 2024 From: Steven Rostedt <rostedt@xxxxxxxxxxx> Date: Tue, 06 Feb 2024 07:09:30 -0500 Subject: eventfs: Do not invalidate dentry in create_file/dir_dentry() To: linux-kernel@xxxxxxxxxxxxxxx, stable@xxxxxxxxxxxxxxx Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>, Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>, Sasha Levin <sashal@xxxxxxxxxx>, Masami Hiramatsu <mhiramat@xxxxxxxxxx>, Mark Rutland <mark.rutland@xxxxxxx>, Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>, Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>, Naresh Kamboju <naresh.kamboju@xxxxxxxxxx>, Linux Kernel Functional Testing <lkft@xxxxxxxxxx> Message-ID: <20240206120950.446963304@xxxxxxxxxxxxxxxxxxxxx> From: "Steven Rostedt (Google)" <rostedt@xxxxxxxxxxx> commit 71cade82f2b553a74d046c015c986f2df165696f upstream. 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@xxxxxxxxxx/ Link: https://lkml.kernel.org/r/20231120235154.422970988@xxxxxxxxxxx Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Fixes: 407c6726ca71 ("eventfs: Use simple_recursive_removal() to clean up dentries") Reported-by: Mark Rutland <mark.rutland@xxxxxxx> Reported-by: Naresh Kamboju <naresh.kamboju@xxxxxxxxxx> Reported-by: Linux Kernel Functional Testing <lkft@xxxxxxxxxx> Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/tracefs/event_inode.c | 19 ++++++------------- 1 file changed, 6 insertions(+), 13 deletions(-) --- a/fs/tracefs/event_inode.c +++ b/fs/tracefs/event_inode.c @@ -326,7 +326,6 @@ create_file_dentry(struct eventfs_inode 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 * 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 * * 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; } /** Patches currently in stable-queue which might be from rostedt@xxxxxxxxxx are queue-6.6/eventfs-keep-all-directory-links-at-1.patch queue-6.6/eventfs-make-sure-that-parent-d_inode-is-locked-in-creating-files-dirs.patch queue-6.6/eventfs-save-directory-inodes-in-the-eventfs_inode-structure.patch queue-6.6/revert-eventfs-save-ownership-and-mode.patch queue-6.6/tracefs-zero-out-the-tracefs_inode-when-allocating-it.patch queue-6.6/eventfs-read-ei-entries-before-ei-children-in-eventfs_iterate.patch queue-6.6/eventfs-do-not-invalidate-dentry-in-create_file-dir_dentry.patch queue-6.6/eventfs-fix-file-and-directory-uid-and-gid-ownership.patch queue-6.6/eventfs-remove-lookup-parameter-from-create_dir-file_dentry.patch queue-6.6/eventfs-use-gfp_nofs-for-allocation-when-eventfs_mutex-is-held.patch queue-6.6/eventfs-remove-fsnotify-functions-from-lookup.patch queue-6.6/eventfs-use-err_cast-in-eventfs_create_events_dir.patch queue-6.6/revert-eventfs-use-simple_recursive_removal-to-clean-up-dentries.patch queue-6.6/eventfs-use-simple_recursive_removal-to-clean-up-dentries.patch queue-6.6/eventfs-stop-using-dcache_readdir-for-getdents.patch queue-6.6/eventfs-have-event-files-and-directories-default-to-parent-uid-and-gid.patch queue-6.6/eventfs-use-eventfs_remove_events_dir.patch queue-6.6/eventfs-delete-eventfs_inode-when-the-last-dentry-is-freed.patch queue-6.6/tracefs-avoid-using-the-ei-dentry-pointer-unnecessarily.patch queue-6.6/tracefs-remove-stale-update_gid-code.patch queue-6.6/eventfs-initialize-the-tracefs-inode-properly.patch queue-6.6/eventfs-remove-special-processing-of-dput-of-events-directory.patch queue-6.6/eventfs-save-ownership-and-mode.patch queue-6.6/tracefs-check-for-dentry-d_inode-exists-in-set_gid.patch queue-6.6/eventfs-do-ctx-pos-update-for-all-iterations-in-eventfs_iterate.patch queue-6.6/tracefs-dentry-lookup-crapectomy.patch queue-6.6/eventfs-move-taking-of-inode_lock-into-dcache_dir_open_wrapper.patch queue-6.6/eventfs-have-a-free_ei-that-just-frees-the-eventfs_inode.patch queue-6.6/revert-eventfs-remove-is_freed-union-with-rcu-head.patch queue-6.6/eventfs-have-the-inodes-all-for-files-and-directories-all-be-the-same.patch queue-6.6/eventfs-use-kcalloc-instead-of-kzalloc.patch queue-6.6/eventfs-test-for-ei-is_freed-when-accessing-ei-dentry.patch queue-6.6/eventfs-fix-bitwise-fields-for-is_events.patch queue-6.6/eventfs-fix-warn_on-in-create_file_dentry.patch queue-6.6/eventfs-fix-events-beyond-name_max-blocking-tasks.patch queue-6.6/eventfs-shortcut-eventfs_iterate-by-skipping-entries-already-read.patch queue-6.6/revert-eventfs-do-not-allow-null-parent-to-eventfs_start_creating.patch queue-6.6/eventfs-do-not-allow-null-parent-to-eventfs_start_creating.patch queue-6.6/eventfs-do-not-create-dentries-nor-inodes-in-iterate_shared.patch queue-6.6/eventfs-have-eventfs_iterate-stop-immediately-if-ei-is_freed-is-set.patch queue-6.6/eventfs-fix-typo-in-eventfs_inode-union-comment.patch queue-6.6/eventfs-remove-expectation-that-ei-is_freed-means-ei-dentry-null.patch queue-6.6/eventfs-restructure-eventfs_inode-structure-to-be-more-condensed.patch queue-6.6/eventfs-warn-if-an-eventfs_inode-is-freed-without-is_freed-being-set.patch queue-6.6/eventfs-get-rid-of-dentry-pointers-without-refcounts.patch queue-6.6/eventfs-remove-unused-d_parent-pointer-field.patch queue-6.6/eventfs-hold-eventfs_mutex-when-calling-callback-functions.patch queue-6.6/eventfs-remove-is_freed-union-with-rcu-head.patch queue-6.6/tracefs-eventfs-modify-mismatched-function-name.patch queue-6.6/eventfs-fix-kerneldoc-of-eventfs_remove_rec.patch queue-6.6/tracefs-eventfs-use-root-and-instance-inodes-as-default-ownership.patch queue-6.6/revert-eventfs-check-for-null-ef-in-eventfs_set_attr.patch queue-6.6/eventfs-fix-failure-path-in-eventfs_create_events_dir.patch queue-6.6/eventfs-clean-up-dentry-ops-and-add-revalidate-function.patch