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From: Al Viro <viro@zeniv.linux.org.uk>
To: linux-fsdevel@vger.kernel.org
Cc: agruenba@redhat.com, amir73il@gmail.com, brauner@kernel.org,
	ceph-devel@vger.kernel.org, dhowells@redhat.com,
	hubcap@omnibond.com, jack@suse.cz, krisman@kernel.org,
	linux-nfs@vger.kernel.org, miklos@szeredi.hu,
	torvalds@linux-foundation.org
Subject: [PATCH 04/20] dissolve external_name.u into separate members
Date: Fri, 10 Jan 2025 02:42:47 +0000	[thread overview]
Message-ID: <20250110024303.4157645-4-viro@zeniv.linux.org.uk> (raw)
In-Reply-To: <20250110024303.4157645-1-viro@zeniv.linux.org.uk>

kept separate from the previous commit to keep the noise separate
from actual changes...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/dcache.c | 22 ++++++++++------------
 1 file changed, 10 insertions(+), 12 deletions(-)

diff --git a/fs/dcache.c b/fs/dcache.c
index f387dc97df86..7d42ca367522 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -296,10 +296,8 @@ static inline int dentry_cmp(const struct dentry *dentry, const unsigned char *c
 }
 
 struct external_name {
-	struct {
-		atomic_t count;		// ->count and ->head can't be combined
-		struct rcu_head head;	// see take_dentry_name_snapshot()
-	} u;
+	atomic_t count;		// ->count and ->head can't be combined
+	struct rcu_head head;	// see take_dentry_name_snapshot()
 	unsigned char name[];
 };
 
@@ -344,7 +342,7 @@ void take_dentry_name_snapshot(struct name_snapshot *name, struct dentry *dentry
 		struct external_name *p;
 		p = container_of(s, struct external_name, name[0]);
 		// get a valid reference
-		if (unlikely(!atomic_inc_not_zero(&p->u.count)))
+		if (unlikely(!atomic_inc_not_zero(&p->count)))
 			goto retry;
 		name->name.name = s;
 	}
@@ -361,8 +359,8 @@ void release_dentry_name_snapshot(struct name_snapshot *name)
 	if (unlikely(name->name.name != name->inline_name.string)) {
 		struct external_name *p;
 		p = container_of(name->name.name, struct external_name, name[0]);
-		if (unlikely(atomic_dec_and_test(&p->u.count)))
-			kfree_rcu(p, u.head);
+		if (unlikely(atomic_dec_and_test(&p->count)))
+			kfree_rcu(p, head);
 	}
 }
 EXPORT_SYMBOL(release_dentry_name_snapshot);
@@ -400,7 +398,7 @@ static void dentry_free(struct dentry *dentry)
 	WARN_ON(!hlist_unhashed(&dentry->d_u.d_alias));
 	if (unlikely(dname_external(dentry))) {
 		struct external_name *p = external_name(dentry);
-		if (likely(atomic_dec_and_test(&p->u.count))) {
+		if (likely(atomic_dec_and_test(&p->count))) {
 			call_rcu(&dentry->d_u.d_rcu, __d_free_external);
 			return;
 		}
@@ -1681,7 +1679,7 @@ static struct dentry *__d_alloc(struct super_block *sb, const struct qstr *name)
 			kmem_cache_free(dentry_cache, dentry); 
 			return NULL;
 		}
-		atomic_set(&p->u.count, 1);
+		atomic_set(&p->count, 1);
 		dname = p->name;
 	} else  {
 		dname = dentry->d_shortname.string;
@@ -2774,15 +2772,15 @@ static void copy_name(struct dentry *dentry, struct dentry *target)
 	if (unlikely(dname_external(dentry)))
 		old_name = external_name(dentry);
 	if (unlikely(dname_external(target))) {
-		atomic_inc(&external_name(target)->u.count);
+		atomic_inc(&external_name(target)->count);
 		dentry->d_name = target->d_name;
 	} else {
 		dentry->d_shortname = target->d_shortname;
 		dentry->d_name.name = dentry->d_shortname.string;
 		dentry->d_name.hash_len = target->d_name.hash_len;
 	}
-	if (old_name && likely(atomic_dec_and_test(&old_name->u.count)))
-		kfree_rcu(old_name, u.head);
+	if (old_name && likely(atomic_dec_and_test(&old_name->count)))
+		kfree_rcu(old_name, head);
 }
 
 /*
-- 
2.39.5


  parent reply	other threads:[~2025-01-10  2:43 UTC|newest]

Thread overview: 96+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-01-10  2:38 [PATCHES][RFC][CFT] ->d_revalidate() calling conventions changes (->d_parent/->d_name stability problems) Al Viro
2025-01-10  2:42 ` [PATCH 01/20] make sure that DNAME_INLINE_LEN is a multiple of word size Al Viro
2025-01-10  2:42   ` [PATCH 02/20] dcache: back inline names with a struct-wrapped array of unsigned long Al Viro
2025-01-10  9:35     ` Jan Kara
2025-01-10 16:24       ` Al Viro
2025-01-10  2:42   ` [PATCH 03/20] make take_dentry_name_snapshot() lockless Al Viro
2025-01-10  9:45     ` Jan Kara
2025-01-10  2:42   ` Al Viro [this message]
2025-01-10  7:34     ` [PATCH 04/20] dissolve external_name.u into separate members David Howells
2025-01-10 16:46       ` Al Viro
2025-01-10  2:42   ` [PATCH 05/20] ext4 fast_commit: make use of name_snapshot primitives Al Viro
2025-01-10  9:15     ` Jan Kara
2025-01-10  2:42   ` [PATCH 06/20] generic_ci_d_compare(): use shortname_storage Al Viro
2025-01-10  2:42   ` [PATCH 07/20] Pass parent directory inode and expected name to ->d_revalidate() Al Viro
2025-01-10  2:42   ` [PATCH 08/20] afs_d_revalidate(): use stable name and parent inode passed by caller Al Viro
2025-01-10  2:42   ` [PATCH 09/20] ceph_d_revalidate(): use stable " Al Viro
2025-01-10 19:45     ` Viacheslav Dubeyko
2025-01-10  2:42   ` [PATCH 10/20] ceph_d_revalidate(): propagate stable name down into request enconding Al Viro
2025-01-10  2:42   ` [PATCH 11/20] fscrypt_d_revalidate(): use stable parent inode passed by caller Al Viro
2025-01-10  2:42   ` [PATCH 12/20] exfat_d_revalidate(): " Al Viro
2025-01-10  2:42   ` [PATCH 13/20] vfat_revalidate{,_ci}(): " Al Viro
2025-01-10  2:42   ` [PATCH 14/20] fuse_dentry_revalidate(): use stable parent inode and name " Al Viro
2025-01-10  2:42   ` [PATCH 15/20] gfs2_drevalidate(): " Al Viro
2025-01-10 19:20     ` Andreas Grünbacher
2025-01-10  2:42   ` [PATCH 16/20] nfs{,4}_lookup_validate(): use stable parent inode " Al Viro
2025-01-10  2:43   ` [PATCH 17/20] nfs: fix ->d_revalidate() UAF on ->d_name accesses Al Viro
2025-01-10  2:43   ` [PATCH 18/20] ocfs2_dentry_revalidate(): use stable parent inode and name passed by caller Al Viro
2025-01-10  9:54     ` Jan Kara
2025-01-10  2:43   ` [PATCH 19/20] orangefs_d_revalidate(): " Al Viro
2025-01-10  3:06     ` Linus Torvalds
2025-01-10  2:43   ` [PATCH 20/20] 9p: fix ->rename_sem exclusion Al Viro
2025-01-10  3:11     ` Linus Torvalds
2025-01-10  5:53       ` Al Viro
2025-01-10  9:21   ` [PATCH 01/20] make sure that DNAME_INLINE_LEN is a multiple of word size Jan Kara
2025-01-16  5:21 ` [PATCHES v2][RFC][CFT] ->d_revalidate() calling conventions changes (->d_parent/->d_name stability problems) Al Viro
2025-01-16  5:22   ` [PATCH v2 01/20] make sure that DNAME_INLINE_LEN is a multiple of word size Al Viro
2025-01-16  5:22     ` [PATCH v2 02/20] dcache: back inline names with a struct-wrapped array of unsigned long Al Viro
2025-01-16  5:23     ` [PATCH v2 03/20] make take_dentry_name_snapshot() lockless Al Viro
2025-01-16  5:23     ` [PATCH v2 04/20] dissolve external_name.u into separate members Al Viro
2025-01-16 10:06       ` Jan Kara
2025-01-16  5:23     ` [PATCH v2 05/20] ext4 fast_commit: make use of name_snapshot primitives Al Viro
2025-01-16  5:23     ` [PATCH v2 06/20] generic_ci_d_compare(): use shortname_storage Al Viro
2025-01-16 15:38       ` Gabriel Krisman Bertazi
2025-01-16 15:46         ` Al Viro
2025-01-16 15:53           ` Gabriel Krisman Bertazi
2025-01-16  5:23     ` [PATCH v2 07/20] Pass parent directory inode and expected name to ->d_revalidate() Al Viro
2025-01-16 15:15       ` Gabriel Krisman Bertazi
2025-01-17 18:55       ` Jeff Layton
2025-01-17 19:00         ` Al Viro
2025-01-16  5:23     ` [PATCH v2 08/20] afs_d_revalidate(): use stable name and parent inode passed by caller Al Viro
2025-01-22 20:27       ` David Howells
2025-01-22 21:01         ` Al Viro
2025-01-22 21:24           ` Al Viro
2025-01-22 21:55             ` David Howells
2025-01-16  5:23     ` [PATCH v2 09/20] ceph_d_revalidate(): use stable " Al Viro
2025-01-17 18:35       ` Jeff Layton
2025-01-16  5:23     ` [PATCH v2 10/20] ceph_d_revalidate(): propagate stable name down into request enconding Al Viro
2025-01-17 18:35       ` Jeff Layton
2025-01-16  5:23     ` [PATCH v2 11/20] fscrypt_d_revalidate(): use stable parent inode passed by caller Al Viro
2025-01-17 15:20       ` Jeff Layton
2025-01-16  5:23     ` [PATCH v2 12/20] exfat_d_revalidate(): " Al Viro
2025-01-16  5:23     ` [PATCH v2 13/20] vfat_revalidate{,_ci}(): " Al Viro
2025-01-17 15:22       ` Jeff Layton
2025-01-16  5:23     ` [PATCH v2 14/20] fuse_dentry_revalidate(): use stable parent inode and name " Al Viro
2025-01-17 15:18       ` Jeff Layton
2025-01-16  5:23     ` [PATCH v2 15/20] gfs2_drevalidate(): " Al Viro
2025-01-16  5:23     ` [PATCH v2 16/20] nfs{,4}_lookup_validate(): use stable parent inode " Al Viro
2025-01-17 14:05       ` Jeff Layton
2025-01-16  5:23     ` [PATCH v2 17/20] nfs: fix ->d_revalidate() UAF on ->d_name accesses Al Viro
2025-01-17 15:12       ` Jeff Layton
2025-01-16  5:23     ` [PATCH v2 18/20] ocfs2_dentry_revalidate(): use stable parent inode and name passed by caller Al Viro
2025-01-16  5:23     ` [PATCH v2 19/20] orangefs_d_revalidate(): " Al Viro
2025-01-16  5:23     ` [PATCH v2 20/20] 9p: fix ->rename_sem exclusion Al Viro
2025-01-23  1:45   ` [PATCHES v3][RFC][CFT] ->d_revalidate() calling conventions changes (->d_parent/->d_name stability problems) Al Viro
2025-01-23  1:46     ` [PATCH v3 01/20] make sure that DNAME_INLINE_LEN is a multiple of word size Al Viro
2025-01-23  1:46       ` [PATCH v3 02/20] dcache: back inline names with a struct-wrapped array of unsigned long Al Viro
2025-01-23  1:46       ` [PATCH v3 03/20] make take_dentry_name_snapshot() lockless Al Viro
2025-01-23  1:46       ` [PATCH v3 04/20] dissolve external_name.u into separate members Al Viro
2025-01-23  1:46       ` [PATCH v3 05/20] ext4 fast_commit: make use of name_snapshot primitives Al Viro
2025-01-23  1:46       ` [PATCH v3 06/20] generic_ci_d_compare(): use shortname_storage Al Viro
2025-01-23  1:46       ` [PATCH v3 07/20] Pass parent directory inode and expected name to ->d_revalidate() Al Viro
2025-01-23  1:46       ` [PATCH v3 08/20] afs_d_revalidate(): use stable name and parent inode passed by caller Al Viro
2025-01-23  1:46       ` [PATCH v3 09/20] ceph_d_revalidate(): use stable " Al Viro
2025-01-23  1:46       ` [PATCH v3 10/20] ceph_d_revalidate(): propagate stable name down into request encoding Al Viro
2025-01-23  1:46       ` [PATCH v3 11/20] fscrypt_d_revalidate(): use stable parent inode passed by caller Al Viro
2025-01-23  1:46       ` [PATCH v3 12/20] exfat_d_revalidate(): " Al Viro
2025-01-23  1:46       ` [PATCH v3 13/20] vfat_revalidate{,_ci}(): " Al Viro
2025-01-23  1:46       ` [PATCH v3 14/20] fuse_dentry_revalidate(): use stable parent inode and name " Al Viro
2025-01-23 10:51         ` Miklos Szeredi
2025-01-23  1:46       ` [PATCH v3 15/20] gfs2_drevalidate(): " Al Viro
2025-01-23  1:46       ` [PATCH v3 16/20] nfs{,4}_lookup_validate(): use stable parent inode " Al Viro
2025-01-23  1:46       ` [PATCH v3 17/20] nfs: fix ->d_revalidate() UAF on ->d_name accesses Al Viro
2025-01-23  1:46       ` [PATCH v3 18/20] ocfs2_dentry_revalidate(): use stable parent inode and name passed by caller Al Viro
2025-01-23  1:46       ` [PATCH v3 19/20] orangefs_d_revalidate(): " Al Viro
2025-01-25 16:25         ` Mike Marshall
2025-01-23  1:46       ` [PATCH v3 20/20] 9p: fix ->rename_sem exclusion Al Viro

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