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 01/20] make sure that DNAME_INLINE_LEN is a multiple of word size
Date: Fri, 10 Jan 2025 02:42:44 +0000 [thread overview]
Message-ID: <20250110024303.4157645-1-viro@zeniv.linux.org.uk> (raw)
In-Reply-To: <20250110023854.GS1977892@ZenIV>
... calling the number of words DNAME_INLINE_WORDS.
The next step will be to have a structure to hold inline name arrays
(both in dentry and in name_snapshot) and use that to alias the
existing arrays of unsigned char there. That will allow both
full-structure copies and convenient word-by-word accesses.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
fs/dcache.c | 4 +---
include/linux/dcache.h | 8 +++++---
2 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/fs/dcache.c b/fs/dcache.c
index b4d5e9e1e43d..ea0f0bea511b 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -2748,9 +2748,7 @@ static void swap_names(struct dentry *dentry, struct dentry *target)
/*
* Both are internal.
*/
- unsigned int i;
- BUILD_BUG_ON(!IS_ALIGNED(DNAME_INLINE_LEN, sizeof(long)));
- for (i = 0; i < DNAME_INLINE_LEN / sizeof(long); i++) {
+ for (int i = 0; i < DNAME_INLINE_WORDS; i++) {
swap(((long *) &dentry->d_iname)[i],
((long *) &target->d_iname)[i]);
}
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index bff956f7b2b9..42dd89beaf4e 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -68,15 +68,17 @@ extern const struct qstr dotdot_name;
* large memory footprint increase).
*/
#ifdef CONFIG_64BIT
-# define DNAME_INLINE_LEN 40 /* 192 bytes */
+# define DNAME_INLINE_WORDS 5 /* 192 bytes */
#else
# ifdef CONFIG_SMP
-# define DNAME_INLINE_LEN 36 /* 128 bytes */
+# define DNAME_INLINE_WORDS 9 /* 128 bytes */
# else
-# define DNAME_INLINE_LEN 44 /* 128 bytes */
+# define DNAME_INLINE_WORDS 11 /* 128 bytes */
# endif
#endif
+#define DNAME_INLINE_LEN (DNAME_INLINE_WORDS*sizeof(unsigned long))
+
#define d_lock d_lockref.lock
struct dentry {
--
2.39.5
next prev 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 ` Al Viro [this message]
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 ` [PATCH 04/20] dissolve external_name.u into separate members Al Viro
2025-01-10 7:34 ` 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
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20250110024303.4157645-1-viro@zeniv.linux.org.uk \
--to=viro@zeniv.linux.org.uk \
--cc=agruenba@redhat.com \
--cc=amir73il@gmail.com \
--cc=brauner@kernel.org \
--cc=ceph-devel@vger.kernel.org \
--cc=dhowells@redhat.com \
--cc=hubcap@omnibond.com \
--cc=jack@suse.cz \
--cc=krisman@kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-nfs@vger.kernel.org \
--cc=miklos@szeredi.hu \
--cc=torvalds@linux-foundation.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox