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From: Dmitry Kadashev <[email protected]>
To: Jens Axboe <[email protected]>,
	Alexander Viro <[email protected]>,
	Christian Brauner <[email protected]>,
	Linus Torvalds <[email protected]>
Cc: [email protected], [email protected],
	Dmitry Kadashev <[email protected]>
Subject: [PATCH  07/14] namei: prepare do_mknodat for refactoring
Date: Thu, 15 Jul 2021 17:35:53 +0700	[thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>

This is just a preparation for the move of the main mknodat 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.

There are 3 changes to the flow here:

1. may_mknod() call is repeated on ESTALE retry now. It's OK to do since
the call is very cheap (and ESTALE retry is a slow path) and the result
doesn't change;

2. Just like the similar patches for rmdir and others a few commits
before, previously on filename_create() error the function used to exit
immediately, and now it will check the return code to see if ESTALE
retry is appropriate. The filename_create() does its own retries on
ESTALE (at least via filename_parentat() used inside), but this extra
check should be completely fine.

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

Cc: Linus Torvalds <[email protected]>
Cc: Al Viro <[email protected]>
Cc: Christian Brauner <[email protected]>
Suggested-by: Linus Torvalds <[email protected]>
Link: https://lore.kernel.org/io-uring/CAHk-=wijsw1QSsQHFu_6dEoZEr_zvT7++WJWohcuEkLqqXBGrQ@mail.gmail.com/
Link: https://lore.kernel.org/io-uring/CAHk-=wjFd0qn6asio=zg7zUTRmSty_TpAEhnwym1Qb=wFgCKzA@mail.gmail.com/
Signed-off-by: Dmitry Kadashev <[email protected]>
---
 fs/namei.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index 50ab1cd00983..4008867e516d 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -3754,10 +3754,10 @@ static int do_mknodat(int dfd, struct filename *name, umode_t mode,
 	int error;
 	unsigned int lookup_flags = 0;
 
+retry:
 	error = may_mknod(mode);
 	if (error)
 		goto out1;
-retry:
 	dentry = __filename_create(dfd, name, &path, lookup_flags);
 	error = PTR_ERR(dentry);
 	if (IS_ERR(dentry))
@@ -3788,11 +3788,11 @@ static int do_mknodat(int dfd, struct filename *name, umode_t mode,
 	}
 out2:
 	done_path_create(&path, dentry);
-	if (retry_estale(error, lookup_flags)) {
+out1:
+	if (unlikely(retry_estale(error, lookup_flags))) {
 		lookup_flags |= LOOKUP_REVAL;
 		goto retry;
 	}
-out1:
 	putname(name);
 	return error;
 }
-- 
2.30.2


  parent reply	other threads:[~2021-07-15 10:36 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-15 10:35 [PATCH 00/14] namei: clean up retry logic in various do_* functions Dmitry Kadashev
2021-07-15 10:35 ` [PATCH 01/14] namei: prepare do_rmdir for refactoring Dmitry Kadashev
2021-07-15 19:49   ` Al Viro
2021-07-20  6:52     ` Dmitry Kadashev
2021-07-15 10:35 ` [PATCH 02/14] namei: clean up do_rmdir retry logic Dmitry Kadashev
2021-07-15 20:02   ` Al Viro
2021-07-15 10:35 ` [PATCH 03/14] namei: prepare do_unlinkat for refactoring Dmitry Kadashev
2021-07-15 10:35 ` [PATCH 04/14] namei: clean up do_unlinkat retry logic Dmitry Kadashev
2021-07-15 10:35 ` [PATCH 05/14] namei: prepare do_mkdirat for refactoring Dmitry Kadashev
2021-07-15 20:17   ` Al Viro
2021-07-20  6:59     ` Dmitry Kadashev
2021-07-20 13:55       ` Al Viro
2021-07-21 10:02         ` Dmitry Kadashev
2021-07-15 10:35 ` [PATCH 06/14] namei: clean up do_mkdirat retry logic Dmitry Kadashev
2021-07-15 10:35 ` Dmitry Kadashev [this message]
2021-07-15 10:35 ` [PATCH 08/14] namei: clean up do_mknodat " Dmitry Kadashev
2021-07-15 10:35 ` [PATCH 09/14] namei: prepare do_symlinkat for refactoring Dmitry Kadashev
2021-07-15 10:35 ` [PATCH 10/14] namei: clean up do_symlinkat retry logic Dmitry Kadashev
2021-07-15 10:35 ` [PATCH 11/14] namei: prepare do_linkat for refactoring Dmitry Kadashev
2021-07-15 10:35 ` [PATCH 12/14] namei: clean up do_linkat retry logic Dmitry Kadashev
2021-07-15 10:35 ` [PATCH 13/14] namei: prepare do_renameat2 for refactoring Dmitry Kadashev
2021-07-15 10:36 ` [PATCH 14/14] namei: clean up do_renameat2 retry logic Dmitry Kadashev
2021-07-15 10:39 ` [PATCH 00/14] namei: clean up retry logic in various do_* functions Dmitry Kadashev

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