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+D... Link: https://lore.kernel.org/linux-trace-kernel/20240104220048.333115095@goodmis....
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(-)
diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c index c73fb1f7ddbc..a1934e0eea3b 100644 --- a/fs/tracefs/event_inode.c +++ b/fs/tracefs/event_inode.c @@ -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;