This is a note to let you know that I've just added the patch titled
eventfs: Read ei->entries before ei->children in eventfs_iterate()
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-read-ei-entries-before-ei-children-in-eventfs_iterate.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 13:10:56 2024
From: Steven Rostedt <rostedt@xxxxxxxxxxx>
Date: Tue, 06 Feb 2024 07:09:45 -0500
Subject: eventfs: Read ei->entries before ei->children in eventfs_iterate()
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>, Al Viro <viro@xxxxxxxxxxxxxxxxxx>, Christian Brauner <brauner@xxxxxxxxxx>
Message-ID: <20240206120952.892527913@xxxxxxxxxxxxxxxxxxxxx>
From: "Steven Rostedt (Google)" <rostedt@xxxxxxxxxxx>
commit 704f960dbee2f1634f4b4e16f208cb16eaf41c1e upstream.
In order to apply a shortcut to skip over the current ctx->pos
immediately, by using the ei->entries array, the reading of that array
should be first. Moving the array reading before the linked list reading
will make the shortcut change diff nicer to read.
Link: https://lore.kernel.org/all/CAHk-=wiKwDUDv3+jCsv-uacDcHDVTYsXtBR9=6sGM5mqX+DhOg@xxxxxxxxxxxxxx/
Link: https://lore.kernel.org/linux-trace-kernel/20240104220048.333115095@xxxxxxxxxxx
Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Christian Brauner <brauner@xxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/tracefs/event_inode.c | 46 +++++++++++++++++++++++-----------------------
1 file changed, 23 insertions(+), 23 deletions(-)
--- a/fs/tracefs/event_inode.c
+++ b/fs/tracefs/event_inode.c
@@ -752,8 +752,8 @@ static int eventfs_iterate(struct file *
* Need to create the dentries and inodes to have a consistent
* inode number.
*/
- list_for_each_entry_srcu(ei_child, &ei->children, list,
- srcu_read_lock_held(&eventfs_srcu)) {
+ for (i = 0; i < ei->nr_entries; i++) {
+ void *cdata = ei->data;
if (c > 0) {
c--;
@@ -762,23 +762,32 @@ static int eventfs_iterate(struct file *
ctx->pos++;
- if (ei_child->is_freed)
- continue;
+ entry = &ei->entries[i];
+ name = entry->name;
- name = ei_child->name;
+ mutex_lock(&eventfs_mutex);
+ /* If ei->is_freed then just bail here, nothing more to do */
+ if (ei->is_freed) {
+ mutex_unlock(&eventfs_mutex);
+ goto out_dec;
+ }
+ r = entry->callback(name, &mode, &cdata, &fops);
+ mutex_unlock(&eventfs_mutex);
+ if (r <= 0)
+ continue;
- dentry = create_dir_dentry(ei, ei_child, ei_dentry);
+ dentry = create_file_dentry(ei, i, ei_dentry, name, mode, cdata, fops);
if (!dentry)
goto out_dec;
ino = dentry->d_inode->i_ino;
dput(dentry);
- if (!dir_emit(ctx, name, strlen(name), ino, DT_DIR))
+ if (!dir_emit(ctx, name, strlen(name), ino, DT_REG))
goto out_dec;
}
- for (i = 0; i < ei->nr_entries; i++) {
- void *cdata = ei->data;
+ list_for_each_entry_srcu(ei_child, &ei->children, list,
+ srcu_read_lock_held(&eventfs_srcu)) {
if (c > 0) {
c--;
@@ -787,27 +796,18 @@ static int eventfs_iterate(struct file *
ctx->pos++;
- entry = &ei->entries[i];
- name = entry->name;
-
- mutex_lock(&eventfs_mutex);
- /* If ei->is_freed then just bail here, nothing more to do */
- if (ei->is_freed) {
- mutex_unlock(&eventfs_mutex);
- goto out_dec;
- }
- r = entry->callback(name, &mode, &cdata, &fops);
- mutex_unlock(&eventfs_mutex);
- if (r <= 0)
+ if (ei_child->is_freed)
continue;
- dentry = create_file_dentry(ei, i, ei_dentry, name, mode, cdata, fops);
+ name = ei_child->name;
+
+ dentry = create_dir_dentry(ei, ei_child, ei_dentry);
if (!dentry)
goto out_dec;
ino = dentry->d_inode->i_ino;
dput(dentry);
- if (!dir_emit(ctx, name, strlen(name), ino, DT_REG))
+ if (!dir_emit(ctx, name, strlen(name), ino, DT_DIR))
goto out_dec;
}
ret = 1;
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
