[RFC][PATCH 10/10] fs: Convert i_count over to refcount_t
From: Peter Zijlstra
Date: Fri Feb 24 2017 - 13:45:01 EST
Now that i_count is a proper refcount, convert it to refcount_t.
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
fs/btrfs/inode.c | 2 +-
fs/f2fs/super.c | 4 ++--
fs/inode.c | 16 ++++++++--------
fs/xfs/xfs_inode.c | 2 +-
fs/xfs/xfs_inode.h | 2 +-
include/linux/fs.h | 5 +++--
kernel/futex.c | 2 +-
7 files changed, 17 insertions(+), 16 deletions(-)
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -3172,7 +3172,7 @@ void btrfs_add_delayed_iput(struct inode
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct btrfs_inode *binode = BTRFS_I(inode);
- if (atomic_add_unless(&inode->i_count, -1, 2))
+ if (refcount_dec_unless(&inode->i_count, 2))
return;
spin_lock(&fs_info->delayed_iput_lock);
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -601,7 +601,7 @@ static int f2fs_drop_inode(struct inode
if ((!inode_unhashed(inode) && inode->i_state & I_SYNC)) {
if (!inode->i_nlink && !is_bad_inode(inode)) {
/* to avoid evict_inode call simultaneously */
- atomic_inc(&inode->i_count);
+ refcount_inc(&inode->i_count);
spin_unlock(&inode->i_lock);
/* some remained atomic pages should discarded */
@@ -621,7 +621,7 @@ static int f2fs_drop_inode(struct inode
fscrypt_put_encryption_info(inode, NULL);
spin_lock(&inode->i_lock);
- atomic_dec(&inode->i_count);
+ refcount_dec(&inode->i_count);
}
return 0;
}
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -135,7 +135,7 @@ int inode_init_always(struct super_block
inode->i_sb = sb;
inode->i_blkbits = sb->s_blocksize_bits;
inode->i_flags = 0;
- atomic_set(&inode->i_count, 2); /* hashed and ref */
+ refcount_set(&inode->i_count, 2); /* hashed and ref */
inode->i_op = &empty_iops;
inode->i_fop = &no_open_fops;
inode->__i_nlink = 1;
@@ -387,7 +387,7 @@ static void init_once(void *foo)
void __iget(struct inode *inode)
{
lockdep_assert_held(&inode->i_lock);
- WARN_ON(!atomic_inc_not_zero(&inode->i_count));
+ refcount_inc(&inode->i_count); /* must not be 0 */
}
/*
@@ -395,7 +395,7 @@ void __iget(struct inode *inode)
*/
void ihold(struct inode *inode)
{
- WARN_ON(atomic_inc_return(&inode->i_count) < 3);
+ refcount_inc(&inode->i_count);
}
EXPORT_SYMBOL(ihold);
@@ -818,7 +818,7 @@ static struct inode *find_inode(struct s
continue;
if (!test(inode, data))
continue;
- if (atomic_inc_not_zero(&inode->i_count))
+ if (refcount_inc_not_zero(&inode->i_count))
goto out_unlock;
goto slow;
}
@@ -875,7 +875,7 @@ static struct inode *find_inode_fast(str
continue;
if (inode->i_sb != sb)
continue;
- if (atomic_inc_not_zero(&inode->i_count))
+ if (refcount_inc_not_zero(&inode->i_count))
goto out_unlock;
goto slow;
}
@@ -1538,7 +1538,7 @@ void iput(struct inode *inode)
BUG_ON(inode->i_state & I_CLEAR);
retry:
- if (atomic_add_unless(&inode->i_count, -1, 2))
+ if (refcount_dec_unless(&inode->i_count, 2))
return;
spin_lock(&inode->i_lock);
@@ -1551,7 +1551,7 @@ void iput(struct inode *inode)
goto retry;
}
- atomic_dec(&inode->i_count); /* 2 -> 1 */
+ refcount_dec(&inode->i_count); /* 2 -> 1 */
WARN_ON(inode->i_state & I_NEW);
/*
@@ -1578,7 +1578,7 @@ void iput(struct inode *inode)
* continue to take the inode out, otherwise someone got a ref
* while we weren't looking.
*/
- if (atomic_cmpxchg(&inode->i_count, 1, 0) != 1) {
+ if (!refcount_dec_if_one(&inode->i_count)) {
spin_unlock(&inode->i_lock);
return;
}
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -1563,7 +1563,7 @@ xfs_itruncate_extents(
int done = 0;
ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
- ASSERT(!atomic_read(&VFS_I(ip)->i_count) ||
+ ASSERT(!refcount_read(&VFS_I(ip)->i_count) ||
xfs_isilocked(ip, XFS_IOLOCK_EXCL));
ASSERT(new_size <= XFS_ISIZE(ip));
ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES);
--- a/fs/xfs/xfs_inode.h
+++ b/fs/xfs/xfs_inode.h
@@ -475,7 +475,7 @@ static inline void xfs_setup_existing_in
#define IHOLD(ip) \
do { \
- ASSERT(atomic_read(&VFS_I(ip)->i_count) > 0) ; \
+ ASSERT(refcount_read(&VFS_I(ip)->i_count) > 0) ; \
ihold(VFS_I(ip)); \
trace_xfs_ihold(ip, _THIS_IP_); \
} while (0)
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -23,6 +23,7 @@
#include <linux/fiemap.h>
#include <linux/rculist_bl.h>
#include <linux/atomic.h>
+#include <linux/refcount.h>
#include <linux/shrinker.h>
#include <linux/migrate_mode.h>
#include <linux/uidgid.h>
@@ -622,7 +623,7 @@ struct inode {
struct rcu_head i_rcu;
};
u64 i_version;
- atomic_t i_count;
+ refcount_t i_count;
atomic_t i_dio_count;
atomic_t i_writecount;
#ifdef CONFIG_IMA
@@ -2713,7 +2714,7 @@ extern unsigned int get_next_ino(void);
static inline int i_count(struct inode *inode)
{
- int i_count = atomic_read(&inode->i_count);
+ int i_count = refcount_read(&inode->i_count);
/*
* In order to preserve the 'old' usage-count semantics, remove the
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -676,7 +676,7 @@ get_futex_key(u32 __user *uaddr, int fsh
* cases, therefore a successful atomic_inc return below will
* guarantee that get_futex_key() will still imply smp_mb(); (B).
*/
- if (WARN_ON_ONCE(!atomic_inc_not_zero(&inode->i_count))) {
+ if (WARN_ON_ONCE(!refcount_inc_not_zero(&inode->i_count))) {
rcu_read_unlock();
put_page(page);