From: "Steven Rostedt (Google)" <rostedt@goodmis.org>
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@mail.gmail.com/
Link: https://lore.kernel.org/linux-trace-kernel/20240104220048.333115095@goodmis.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
(cherry picked from commit 704f960dbee2f1634f4b4e16f208cb16eaf41c1e)
---
fs/tracefs/event_inode.c | 46 ++++++++++++++++++++--------------------
1 file changed, 23 insertions(+), 23 deletions(-)
@@ -752,8 +752,8 @@ static int eventfs_iterate(struct file *file, struct dir_context *ctx)
* 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 *file, struct dir_context *ctx)
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 *file, struct dir_context *ctx)
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;