eventfs: More updates to eventfs_iterate()

With the ongoing descussion of eventfs iterator, a few more changes are required and some changes are just enhancements.

- Stop immediately in the loop if the ei is found to be in the process of being freed.

- Make the ctx->pos update consistent with the skipped previous read index. This fixes a bug with duplicate files being showned by 'ls'.

- Swap reading ei->entries with ei->children to make the next change easier to read

- Add a "shortcut" in the ei->entries array to skip over already read entries.

Steven Rostedt (Google) (4):

      eventfs: Have eventfs_iterate() stop immediately if ei->is_freed is set
      eventfs: Do ctx->pos update for all iterations in  eventfs_iterate()
      eventfs: Read ei->entries before ei->children in eventfs_iterate()
      eventfs: Shortcut eventfs_iterate() by skipping entries already read

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 fs/tracefs/event_inode.c | 67 ++++++++++++++++++++++++++----------------------
 1 file changed, 36 insertions(+), 31 deletions(-)