| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-Id: <20231110204119.3692023-5-willy@infradead.org>
Date: Fri, 10 Nov 2023 20:41:19 +0000
From: "Matthew Wilcox (Oracle)" <willy@...radead.org>
To: Peter Zijlstra <peterz@...radead.org>,
Ingo Molnar <mingo@...hat.com>, Will Deacon <will@...nel.org>,
Waiman Long <longman@...hat.com>
Cc: "Matthew Wilcox (Oracle)" <willy@...radead.org>,
linux-kernel@...r.kernel.org, linux-mm@...ck.org,
Chandan Babu R <chandan.babu@...cle.com>,
"Darrick J . Wong" <djwong@...nel.org>, linux-xfs@...r.kernel.org,
Mateusz Guzik <mjguzik@...il.com>
Subject: [PATCH v3 4/4] xfs: Remove mrlock wrapper
mrlock was an rwsem wrapper that also recorded whether the lock was
held for read or write. Now that we can ask the generic code whether
the lock is held for read or write, we can remove this wrapper and use
an rwsem directly.
As the comment says, we can't use lockdep to assert that the ILOCK is
held for write, because we might be in a workqueue, and we aren't able
to tell lockdep that we do in fact own the lock.
Signed-off-by: Matthew Wilcox (Oracle) <willy@...radead.org>
---
fs/xfs/mrlock.h | 78 ----------------------------------------------
fs/xfs/xfs_inode.c | 22 +++++++------
fs/xfs/xfs_inode.h | 2 +-
fs/xfs/xfs_iops.c | 4 +--
fs/xfs/xfs_linux.h | 2 +-
fs/xfs/xfs_super.c | 4 +--
6 files changed, 18 insertions(+), 94 deletions(-)
delete mode 100644 fs/xfs/mrlock.h
diff --git a/fs/xfs/mrlock.h b/fs/xfs/mrlock.h
deleted file mode 100644
index 79155eec341b..000000000000
--- a/fs/xfs/mrlock.h
+++ /dev/null
@@ -1,78 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Copyright (c) 2000-2006 Silicon Graphics, Inc.
- * All Rights Reserved.
- */
-#ifndef __XFS_SUPPORT_MRLOCK_H__
-#define __XFS_SUPPORT_MRLOCK_H__
-
-#include <linux/rwsem.h>
-
-typedef struct {
- struct rw_semaphore mr_lock;
-#if defined(DEBUG) || defined(XFS_WARN)
- int mr_writer;
-#endif
-} mrlock_t;
-
-#if defined(DEBUG) || defined(XFS_WARN)
-#define mrinit(mrp, name) \
- do { (mrp)->mr_writer = 0; init_rwsem(&(mrp)->mr_lock); } while (0)
-#else
-#define mrinit(mrp, name) \
- do { init_rwsem(&(mrp)->mr_lock); } while (0)
-#endif
-
-#define mrlock_init(mrp, t,n,s) mrinit(mrp, n)
-#define mrfree(mrp) do { } while (0)
-
-static inline void mraccess_nested(mrlock_t *mrp, int subclass)
-{
- down_read_nested(&mrp->mr_lock, subclass);
-}
-
-static inline void mrupdate_nested(mrlock_t *mrp, int subclass)
-{
- down_write_nested(&mrp->mr_lock, subclass);
-#if defined(DEBUG) || defined(XFS_WARN)
- mrp->mr_writer = 1;
-#endif
-}
-
-static inline int mrtryaccess(mrlock_t *mrp)
-{
- return down_read_trylock(&mrp->mr_lock);
-}
-
-static inline int mrtryupdate(mrlock_t *mrp)
-{
- if (!down_write_trylock(&mrp->mr_lock))
- return 0;
-#if defined(DEBUG) || defined(XFS_WARN)
- mrp->mr_writer = 1;
-#endif
- return 1;
-}
-
-static inline void mrunlock_excl(mrlock_t *mrp)
-{
-#if defined(DEBUG) || defined(XFS_WARN)
- mrp->mr_writer = 0;
-#endif
- up_write(&mrp->mr_lock);
-}
-
-static inline void mrunlock_shared(mrlock_t *mrp)
-{
- up_read(&mrp->mr_lock);
-}
-
-static inline void mrdemote(mrlock_t *mrp)
-{
-#if defined(DEBUG) || defined(XFS_WARN)
- mrp->mr_writer = 0;
-#endif
- downgrade_write(&mrp->mr_lock);
-}
-
-#endif /* __XFS_SUPPORT_MRLOCK_H__ */
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index 1ed6bed19bec..7661084ca568 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -208,9 +208,9 @@ xfs_ilock(
}
if (lock_flags & XFS_ILOCK_EXCL)
- mrupdate_nested(&ip->i_lock, XFS_ILOCK_DEP(lock_flags));
+ down_write_nested(&ip->i_lock, XFS_ILOCK_DEP(lock_flags));
else if (lock_flags & XFS_ILOCK_SHARED)
- mraccess_nested(&ip->i_lock, XFS_ILOCK_DEP(lock_flags));
+ down_read_nested(&ip->i_lock, XFS_ILOCK_DEP(lock_flags));
}
/*
@@ -251,10 +251,10 @@ xfs_ilock_nowait(
}
if (lock_flags & XFS_ILOCK_EXCL) {
- if (!mrtryupdate(&ip->i_lock))
+ if (!down_write_trylock(&ip->i_lock))
goto out_undo_mmaplock;
} else if (lock_flags & XFS_ILOCK_SHARED) {
- if (!mrtryaccess(&ip->i_lock))
+ if (!down_read_trylock(&ip->i_lock))
goto out_undo_mmaplock;
}
return 1;
@@ -303,9 +303,9 @@ xfs_iunlock(
up_read(&VFS_I(ip)->i_mapping->invalidate_lock);
if (lock_flags & XFS_ILOCK_EXCL)
- mrunlock_excl(&ip->i_lock);
+ up_write(&ip->i_lock);
else if (lock_flags & XFS_ILOCK_SHARED)
- mrunlock_shared(&ip->i_lock);
+ up_read(&ip->i_lock);
trace_xfs_iunlock(ip, lock_flags, _RET_IP_);
}
@@ -324,7 +324,7 @@ xfs_ilock_demote(
~(XFS_IOLOCK_EXCL|XFS_MMAPLOCK_EXCL|XFS_ILOCK_EXCL)) == 0);
if (lock_flags & XFS_ILOCK_EXCL)
- mrdemote(&ip->i_lock);
+ downgrade_write(&ip->i_lock);
if (lock_flags & XFS_MMAPLOCK_EXCL)
downgrade_write(&VFS_I(ip)->i_mapping->invalidate_lock);
if (lock_flags & XFS_IOLOCK_EXCL)
@@ -338,10 +338,14 @@ xfs_assert_ilocked(
struct xfs_inode *ip,
uint lock_flags)
{
+ /*
+ * Sometimes we assert the ILOCK is held exclusively, but we're in
+ * a workqueue, so lockdep doesn't know we're the owner.
+ */
if (lock_flags & XFS_ILOCK_SHARED)
- rwsem_assert_held(&ip->i_lock.mr_lock);
+ rwsem_assert_held(&ip->i_lock);
else if (lock_flags & XFS_ILOCK_EXCL)
- ASSERT(ip->i_lock.mr_writer);
+ rwsem_assert_held_write_nolockdep(&ip->i_lock);
if (lock_flags & XFS_MMAPLOCK_SHARED)
rwsem_assert_held(&VFS_I(ip)->i_mapping->invalidate_lock);
diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h
index dd8b8339ba1b..3cade5903fda 100644
--- a/fs/xfs/xfs_inode.h
+++ b/fs/xfs/xfs_inode.h
@@ -39,7 +39,7 @@ typedef struct xfs_inode {
/* Transaction and locking information. */
struct xfs_inode_log_item *i_itemp; /* logging information */
- mrlock_t i_lock; /* inode lock */
+ struct rw_semaphore i_lock; /* inode lock */
atomic_t i_pincount; /* inode pin count */
struct llist_node i_gclist; /* deferred inactivation list */
diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index e711668d601b..79010d60ee21 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -1284,9 +1284,9 @@ xfs_setup_inode(
*/
lockdep_set_class(&inode->i_rwsem,
&inode->i_sb->s_type->i_mutex_dir_key);
- lockdep_set_class(&ip->i_lock.mr_lock, &xfs_dir_ilock_class);
+ lockdep_set_class(&ip->i_lock, &xfs_dir_ilock_class);
} else {
- lockdep_set_class(&ip->i_lock.mr_lock, &xfs_nondir_ilock_class);
+ lockdep_set_class(&ip->i_lock, &xfs_nondir_ilock_class);
}
/*
diff --git a/fs/xfs/xfs_linux.h b/fs/xfs/xfs_linux.h
index d7873e0360f0..ec3c6c138a63 100644
--- a/fs/xfs/xfs_linux.h
+++ b/fs/xfs/xfs_linux.h
@@ -22,7 +22,6 @@ typedef __u32 xfs_nlink_t;
#include "xfs_types.h"
#include "kmem.h"
-#include "mrlock.h"
#include <linux/semaphore.h>
#include <linux/mm.h>
@@ -51,6 +50,7 @@ typedef __u32 xfs_nlink_t;
#include <linux/notifier.h>
#include <linux/delay.h>
#include <linux/log2.h>
+#include <linux/rwsem.h>
#include <linux/spinlock.h>
#include <linux/random.h>
#include <linux/ctype.h>
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index 764304595e8b..cd0200ed51f0 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -724,9 +724,7 @@ xfs_fs_inode_init_once(
/* xfs inode */
atomic_set(&ip->i_pincount, 0);
spin_lock_init(&ip->i_flags_lock);
-
- mrlock_init(&ip->i_lock, MRLOCK_ALLOW_EQUAL_PRI|MRLOCK_BARRIER,
- "xfsino", ip->i_ino);
+ init_rwsem(&ip->i_lock);
}
/*
--
2.42.0
Powered by blists - more mailing lists