eventfs: Linus's updates for 6.7

This is a backport of all the work that lead up to the work that Linus made on eventfs. I trust Linus's version more so than the versions in 6.6 and 6.7. There may be plenty of hidden issues due to the design.

This is the update for 6.7. It includes Linus's updates as well as all the patches leading up to them.

I ran these through my full test suite that I use before sending anyting to Linus, althouh I did not run my "bisect" test that walks through the patches. The tests were just run on the end result. I'm currently running my 6.6 version through my tests.

This was created with the following command against v6.7.3:

git log --reverse --no-merges --pretty=oneline v6.7..origin/master fs/tracefs/ | cut -d' ' -f1 |
while read a; do if ! git cherry-pick -x $a; then break; fi ; done

Which adds -x to the cherry pick to add the upstream commit SHAs.

Erick Archer (1):
eventfs: Use kcalloc() instead of kzalloc()

Linus Torvalds (7):
tracefs: remove stale 'update_gid' code
eventfs: Initialize the tracefs inode properly
tracefs: Avoid using the ei->dentry pointer unnecessarily
tracefs: dentry lookup crapectomy
eventfs: Remove unused d_parent pointer field
eventfs: Clean up dentry ops and add revalidate function
eventfs: Get rid of dentry pointers without refcounts

Steven Rostedt (Google) (15):
eventfs: Remove "lookup" parameter from create_dir/file_dentry()
eventfs: Stop using dcache_readdir() for getdents() tracefs/eventfs: Use root and instance inodes as default ownership
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
eventfs: Have the inodes all for files and directories all be the same
eventfs: Do not create dentries nor inodes in iterate_shared
eventfs: Save directory inodes in the eventfs_inode structure
tracefs: Zero out the tracefs_inode when allocating it
eventfs: Warn if an eventfs_inode is freed without is_freed being set
eventfs: Restructure eventfs_inode structure to be more condensed
eventfs: Remove fsnotify*() functions from lookup()
eventfs: Keep all directory links at 1

----

 fs/tracefs/event_inode.c | 905 ++++++++++++++++-------------------------------
 fs/tracefs/inode.c       | 286 +++++++--------
 fs/tracefs/internal.h    |  48 ++-
 3 files changed, 451 insertions(+), 788 deletions(-)