diff mbox series

[v3,17/21] to_shrink_list(): call only if refcount is 0

Message ID	20231124060422.576198-17-viro@zeniv.linux.org.uk (mailing list archive)
State	New, archived
Headers	show Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linux.org.uk header.i=@linux.org.uk header.b="cXc+PzGv" From: Al Viro <viro@zeniv.linux.org.uk> To: linux-fsdevel@vger.kernel.org Cc: Linus Torvalds <torvalds@linux-foundation.org>, Christian Brauner <brauner@kernel.org>, linux-kernel@vger.kernel.org Subject: [PATCH v3 17/21] to_shrink_list(): call only if refcount is 0 Date: Fri, 24 Nov 2023 06:04:18 +0000 Message-Id: <20231124060422.576198-17-viro@zeniv.linux.org.uk> In-Reply-To: <20231124060422.576198-1-viro@zeniv.linux.org.uk> References: <20231124060200.GR38156@ZenIV> <20231124060422.576198-1-viro@zeniv.linux.org.uk> Precedence: bulk MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: Al Viro <viro@ftp.linux.org.uk>
Series	[v3,01/21] switch nfsd_client_rmdir() to use of simple_recursive_removal() \| expand [v3,01/21] switch nfsd_client_rmdir() to use of simple_recursive_removal() [v3,02/21] coda_flag_children(): cope with dentries turning negative [v3,03/21] dentry: switch the lists of children to hlist [v3,04/21] centralize killing dentry from shrink list [v3,05/21] shrink_dentry_list(): no need to check that dentry refcount is marked dead [v3,06/21] fast_dput(): having ->d_delete() is not reason to delay refcount decrement [v3,07/21] fast_dput(): handle underflows gracefully [v3,08/21] fast_dput(): new rules for refcount [v3,09/21] __dput_to_list(): do decrement of refcount in the callers [v3,10/21] make retain_dentry() neutral with respect to refcounting [v3,11/21] __dentry_kill(): get consistent rules for victim's refcount [v3,12/21] dentry_kill(): don't bother with retain_dentry() on slow path [v3,13/21] Call retain_dentry() with refcount 0 [v3,14/21] fold the call of retain_dentry() into fast_dput() [v3,15/21] don't try to cut corners in shrink_lock_dentry() [v3,16/21] fold dentry_kill() into dput() [v3,17/21] to_shrink_list(): call only if refcount is 0 [v3,18/21] switch select_collect{,2}() to use of to_shrink_list() [v3,19/21] d_prune_aliases(): use a shrink list [v3,20/21] __dentry_kill(): new locking scheme [v3,21/21] retain_dentry(): introduce a trimmed-down lockless variant

Commit Message

Al Viro Nov. 24, 2023, 6:04 a.m. UTC

The only thing it does if refcount is not zero is d_lru_del(); no
point, IMO, seeing that plain dput() does nothing of that sort...

Note that 2 of 3 current callers are guaranteed that refcount is 0.

Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/dcache.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff mbox series

Patch

diff --git a/fs/dcache.c b/fs/dcache.c
index 5284b02747cd..704676bf06fd 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -915,8 +915,7 @@  __must_hold(&dentry->d_lock)
 	if (!(dentry->d_flags & DCACHE_SHRINK_LIST)) {
 		if (dentry->d_flags & DCACHE_LRU_LIST)
 			d_lru_del(dentry);
-		if (!dentry->d_lockref.count)
-			d_shrink_add(dentry, list);
+		d_shrink_add(dentry, list);
 	}
 }
 
@@ -1115,10 +1114,8 @@  EXPORT_SYMBOL(d_prune_aliases);
 static inline void shrink_kill(struct dentry *victim, struct list_head *list)
 {
 	struct dentry *parent = victim->d_parent;
-	if (parent != victim) {
-		--parent->d_lockref.count;
+	if (parent != victim && !--parent->d_lockref.count)
 		to_shrink_list(parent, list);
-	}
 	__dentry_kill(victim);
 }