[PATCH v2 03/14] namei: prepare do_unlinkat for refactoring

[Dmitry Kadashev <dkadashev@gmail.com>]

This is just a preparation for the move of the main unlinkat logic to a
separate function to make the logic easier to follow.  This change
contains the flow changes so that the actual change to move the main
logic to a separate function does no change the flow at all.

Just like the similar patch for rmdir a few commits before, there are
two changes here:

1. Previously on filename_parentat() error the function used to exit
immediately, and now it will check the return code to see if ESTALE
retry is appropriate. The filename_parentat() does its own retries on
ESTALE, but this extra check should be completely fine.

2. The retry_estale() check is wrapped in unlikely(). Some other places
already have that and overall it seems to make sense.

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/io-uring/CAHk-=wh=cpt_tQCirzFZRPawRpbuFTZ2MxNpXiyUF+eBXF=+sw@mail.gmail.com/
Link: https://lore.kernel.org/io-uring/CAHk-=wjFd0qn6asio=zg7zUTRmSty_TpAEhnwym1Qb=wFgCKzA@mail.gmail.com/
Signed-off-by: Dmitry Kadashev <dkadashev@gmail.com>
---
 fs/namei.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index fbae4e9fcf53..6253486718d5 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -4148,12 +4148,12 @@ int do_unlinkat(int dfd, struct filename *name)
 	mnt_drop_write(path.mnt);
 exit2:
 	path_put(&path);
-	if (retry_estale(error, lookup_flags)) {
+exit1:
+	if (unlikely(retry_estale(error, lookup_flags))) {
 		lookup_flags |= LOOKUP_REVAL;
 		inode = NULL;
 		goto retry;
 	}
-exit1:
 	putname(name);
 	return error;
 
-- 
2.30.2