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From: Al Viro <viro@zeniv.linux.org.uk>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-fsdevel@vger.kernel.org, Christian Brauner <brauner@kernel.org>
Subject: [PATCH 12/22] Make retain_dentry() neutral with respect to refcounting
Date: Thu,  9 Nov 2023 06:20:46 +0000	[thread overview]
Message-ID: <20231109062056.3181775-12-viro@zeniv.linux.org.uk> (raw)
In-Reply-To: <20231109062056.3181775-1-viro@zeniv.linux.org.uk>

retain_dentry() used to decrement refcount if and only if it returned
true.  Lift those decrements into the callers.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/dcache.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/fs/dcache.c b/fs/dcache.c
index 1899376d0189..1f61a5d03d5b 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -680,7 +680,6 @@ static inline bool retain_dentry(struct dentry *dentry)
 		return false;
 
 	/* retain; LRU fodder */
-	dentry->d_lockref.count--;
 	if (unlikely(!(dentry->d_flags & DCACHE_LRU_LIST)))
 		d_lru_add(dentry);
 	else if (unlikely(!(dentry->d_flags & DCACHE_REFERENCED)))
@@ -744,6 +743,8 @@ static struct dentry *dentry_kill(struct dentry *dentry)
 	} else if (likely(!retain_dentry(dentry))) {
 		__dentry_kill(dentry);
 		return parent;
+	} else {
+		dentry->d_lockref.count--;
 	}
 	/* we are keeping it, after all */
 	if (inode)
@@ -893,6 +894,7 @@ void dput(struct dentry *dentry)
 		rcu_read_unlock();
 
 		if (likely(retain_dentry(dentry))) {
+			dentry->d_lockref.count--;
 			spin_unlock(&dentry->d_lock);
 			return;
 		}
@@ -925,6 +927,8 @@ void dput_to_list(struct dentry *dentry, struct list_head *list)
 	if (!retain_dentry(dentry)) {
 		--dentry->d_lockref.count;
 		to_shrink_list(dentry, list);
+	} else {
+		--dentry->d_lockref.count;
 	}
 	spin_unlock(&dentry->d_lock);
 }
-- 
2.39.2


  parent reply	other threads:[~2023-11-09  6:21 UTC|newest]

Thread overview: 119+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-10-30  0:37 [RFC] simplifying fast_dput(), dentry_kill() et.al Al Viro
2023-10-30 21:53 ` Al Viro
2023-10-30 22:18   ` Linus Torvalds
2023-10-31  0:18     ` Al Viro
2023-10-31  1:53       ` Al Viro
2023-10-31  6:12         ` Al Viro
2023-11-01  6:18           ` Al Viro
2023-11-01  6:20           ` [PATCH 01/15] fast_dput(): having ->d_delete() is not reason to delay refcount decrement Al Viro
2023-11-01  6:20             ` [PATCH 02/15] fast_dput(): handle underflows gracefully Al Viro
2023-11-01  6:20             ` [PATCH 03/15] fast_dput(): new rules for refcount Al Viro
2023-11-01  6:20             ` [PATCH 04/15] __dput_to_list(): do decrement of refcount in the caller Al Viro
2023-11-01  6:20             ` [PATCH 05/15] retain_dentry(): lift decrement of ->d_count into callers Al Viro
2023-11-01  6:20             ` [PATCH 06/15] __dentry_kill(): get consistent rules for ->d_count Al Viro
2023-11-01  6:20             ` [PATCH 07/15] dentry_kill(): don't bother with retain_dentry() on slow path Al Viro
2023-11-01  6:20             ` [PATCH 08/15] Call retain_dentry() with refcount 0 Al Viro
2023-11-01  6:20             ` [PATCH 09/15] fold the call of retain_dentry() into fast_dput() Al Viro
2023-11-01  8:45               ` Al Viro
2023-11-01 17:30                 ` Linus Torvalds
2023-11-01 18:19                   ` Al Viro
2023-11-10  4:20                     ` lockless case of retain_dentry() (was Re: [PATCH 09/15] fold the call of retain_dentry() into fast_dput()) Al Viro
2023-11-10  5:57                       ` Linus Torvalds
2023-11-10  6:22                         ` Linus Torvalds
2023-11-22  6:29                           ` Guo Ren
2023-11-10  8:19                         ` Al Viro
2023-11-22  7:19                         ` Guo Ren
2023-11-22 17:20                           ` Linus Torvalds
2023-11-22 17:52                             ` Linus Torvalds
2023-11-22 18:05                               ` Linus Torvalds
2023-11-22 19:11                               ` Linus Torvalds
2023-11-29  7:14                                 ` Guo Ren
2023-11-29 12:25                                 ` Guo Ren
2023-11-29 14:42                                   ` Linus Torvalds
2023-11-26 16:39                             ` Guo Ren
2023-11-26 16:51                               ` Linus Torvalds
2023-11-30 10:00                                 ` Guo Ren
2023-12-01  1:09                                   ` Linus Torvalds
2023-12-01  3:36                                     ` Guo Ren
2023-12-01  5:15                                       ` Linus Torvalds
2023-12-01  7:31                                         ` Guo Ren
2023-11-26 16:51                               ` Guo Ren
2023-11-26 17:06                               ` Linus Torvalds
2023-11-26 17:59                                 ` Linus Torvalds
2023-11-29  9:52                                 ` Guo Ren
2023-11-01  6:20             ` [PATCH 10/15] don't try to cut corners in shrink_lock_dentry() Al Viro
2023-11-01  6:21             ` [PATCH 11/15] fold dentry_kill() into dput() Al Viro
2023-11-01  6:21             ` [PATCH 12/15] get rid of __dget() Al Viro
2023-11-01  6:21             ` [PATCH 13/15] shrink_dentry_list(): no need to check that dentry refcount is marked dead Al Viro
2023-11-01  6:21             ` [PATCH 14/15] to_shrink_list(): call only if refcount is 0 Al Viro
2023-11-01  6:21             ` [PATCH 15/15] switch select_collect{,2}() to use of to_shrink_list() Al Viro
2023-11-01  2:22       ` [RFC] simplifying fast_dput(), dentry_kill() et.al Al Viro
2023-11-01 14:29         ` Benjamin Coddington
2023-11-05 19:54       ` Al Viro
2023-11-05 21:59         ` Al Viro
2023-11-06  5:53         ` Al Viro
2023-11-07  2:08           ` Al Viro
2023-11-09  6:19             ` [RFC][PATCHSET v2] " Al Viro
2023-11-09  6:20               ` [PATCH 01/22] struct dentry: get rid of randomize_layout idiocy Al Viro
2023-11-09  6:20                 ` [PATCH 02/22] switch nfsd_client_rmdir() to use of simple_recursive_removal() Al Viro
2023-11-09 13:42                   ` Christian Brauner
2023-11-09 14:01                   ` Chuck Lever
2023-11-09 18:47                     ` Al Viro
2023-11-09 18:50                       ` Chuck Lever III
2023-11-09  6:20                 ` [PATCH 03/22] coda_flag_children(): cope with dentries turning negative Al Viro
2023-11-09 13:43                   ` Christian Brauner
2023-11-09  6:20                 ` [PATCH 04/22] dentry: switch the lists of children to hlist Al Viro
2023-11-09 13:48                   ` Christian Brauner
2023-11-09 19:32                     ` Al Viro
2023-11-09  6:20                 ` [PATCH 05/22] centralize killing dentry from shrink list Al Viro
2023-11-09 13:49                   ` Christian Brauner
2023-11-09  6:20                 ` [PATCH 06/22] get rid of __dget() Al Viro
2023-11-09 13:50                   ` Christian Brauner
2023-11-09  6:20                 ` [PATCH 07/22] shrink_dentry_list(): no need to check that dentry refcount is marked dead Al Viro
2023-11-09 13:53                   ` Christian Brauner
2023-11-09 20:28                     ` Al Viro
2023-11-09  6:20                 ` [PATCH 08/22] fast_dput(): having ->d_delete() is not reason to delay refcount decrement Al Viro
2023-11-09 13:58                   ` Christian Brauner
2023-11-09  6:20                 ` [PATCH 09/22] fast_dput(): handle underflows gracefully Al Viro
2023-11-09 14:46                   ` Christian Brauner
2023-11-09 20:39                     ` Al Viro
2023-11-09  6:20                 ` [PATCH 10/22] fast_dput(): new rules for refcount Al Viro
2023-11-09 14:54                   ` Christian Brauner
2023-11-09 20:52                     ` Al Viro
2023-11-09  6:20                 ` [PATCH 11/22] __dput_to_list(): do decrement of refcount in the callers Al Viro
2023-11-09 15:21                   ` Christian Brauner
2023-11-09  6:20                 ` Al Viro [this message]
2023-11-09 15:22                   ` [PATCH 12/22] Make retain_dentry() neutral with respect to refcounting Christian Brauner
2023-11-09  6:20                 ` [PATCH 13/22] __dentry_kill(): get consistent rules for victim's refcount Al Viro
2023-11-09 15:27                   ` Christian Brauner
2023-11-09  6:20                 ` [PATCH 14/22] dentry_kill(): don't bother with retain_dentry() on slow path Al Viro
2023-11-09 15:53                   ` Christian Brauner
2023-11-09 21:29                     ` Al Viro
2023-11-09  6:20                 ` [PATCH 15/22] Call retain_dentry() with refcount 0 Al Viro
2023-11-09 16:09                   ` Christian Brauner
2023-11-09  6:20                 ` [PATCH 16/22] fold the call of retain_dentry() into fast_dput() Al Viro
2023-11-09 16:17                   ` Christian Brauner
2023-11-09  6:20                 ` [PATCH 17/22] don't try to cut corners in shrink_lock_dentry() Al Viro
2023-11-09 17:20                   ` Christian Brauner
2023-11-09 21:45                     ` Al Viro
2023-11-10  9:07                       ` Christian Brauner
2023-11-09 17:39                   ` Linus Torvalds
2023-11-09 18:11                     ` Linus Torvalds
2023-11-09 18:20                     ` Al Viro
2023-11-09  6:20                 ` [PATCH 18/22] fold dentry_kill() into dput() Al Viro
2023-11-09 17:22                   ` Christian Brauner
2023-11-09  6:20                 ` [PATCH 19/22] to_shrink_list(): call only if refcount is 0 Al Viro
2023-11-09 17:29                   ` Christian Brauner
2023-11-09  6:20                 ` [PATCH 20/22] switch select_collect{,2}() to use of to_shrink_list() Al Viro
2023-11-09 17:31                   ` Christian Brauner
2023-11-09  6:20                 ` [PATCH 21/22] d_prune_aliases(): use a shrink list Al Viro
2023-11-09 17:33                   ` Christian Brauner
2023-11-09  6:20                 ` [PATCH 22/22] __dentry_kill(): new locking scheme Al Viro
2023-11-10 13:34                   ` Christian Brauner
2023-11-09 13:33                 ` [PATCH 01/22] struct dentry: get rid of randomize_layout idiocy Christian Brauner
2023-10-31  2:25     ` [RFC] simplifying fast_dput(), dentry_kill() et.al Gao Xiang
2023-10-31  2:29       ` Gao Xiang
2023-10-31  3:02       ` Linus Torvalds
2023-10-31  3:13         ` Gao Xiang
2023-10-31  3:26         ` Al Viro
2023-10-31  3:41           ` Linus Torvalds

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