6.6-stable review patch. If anyone has any objections, please let me know. ------------------ 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;
