Use the newer and standardized functions when performing volatile
accesses. Following text is taken from 4d3199e4ca8e
("locking: Remove ACCESS_ONCE() usage") :
ACCESS_ONCE() does not work reliably on non-scalar types.
For example gcc 4.6 and 4.7 might remove the volatile tag
for such accesses during the SRA (scalar replacement of
aggregates) step:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58145
Signed-off-by: Nikolay Borisov <n.borisov.lkml@xxxxxxxxx>
---
fs/btrfs/delayed-inode.c | 4 ++--
fs/btrfs/super.c | 2 +-
fs/btrfs/transaction.c | 10 +++++-----
fs/btrfs/tree-log.h | 4 ++--
4 files changed, 10 insertions(+), 10 deletions(-)
diff --git a/fs/btrfs/delayed-inode.c b/fs/btrfs/delayed-inode.c
index 80982a83c9fd..353e40fceba8 100644
--- a/fs/btrfs/delayed-inode.c
+++ b/fs/btrfs/delayed-inode.c
@@ -79,7 +79,7 @@ static struct btrfs_delayed_node *btrfs_get_delayed_node(struct inode *inode)
u64 ino = btrfs_ino(inode);
struct btrfs_delayed_node *node;
- node = ACCESS_ONCE(btrfs_inode->delayed_node);
+ node = READ_ONCE(btrfs_inode->delayed_node);
if (node) {
atomic_inc(&node->refs);
return node;
@@ -1292,7 +1292,7 @@ void btrfs_remove_delayed_node(struct inode *inode)
{
struct btrfs_delayed_node *delayed_node;
- delayed_node = ACCESS_ONCE(BTRFS_I(inode)->delayed_node);
+ delayed_node = READ_ONCE(BTRFS_I(inode)->delayed_node);
if (!delayed_node)
return;
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index b5ae7d3d1896..93ed29c2a38b 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -265,7 +265,7 @@ void __btrfs_abort_transaction(struct btrfs_trans_handle *trans,
function, line, errstr);
return;
}
- ACCESS_ONCE(trans->transaction->aborted) = errno;
+ WRITE_ONCE(trans->transaction->aborted, errno);
/* Wake up anybody who may be waiting on this transaction */
wake_up(&fs_info->transaction_wait);
wake_up(&fs_info->transaction_blocked_wait);
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 0e0508f488b2..bd2890c2c9d3 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -866,14 +866,14 @@ static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
if (lock && !atomic_read(&info->open_ioctl_trans) &&
should_end_transaction(trans) &&
- ACCESS_ONCE(cur_trans->state) == TRANS_STATE_RUNNING) {
+ READ_ONCE(cur_trans->state) == TRANS_STATE_RUNNING) {
spin_lock(&info->trans_lock);
if (cur_trans->state == TRANS_STATE_RUNNING)
cur_trans->state = TRANS_STATE_BLOCKED;
spin_unlock(&info->trans_lock);
}
- if (lock && ACCESS_ONCE(cur_trans->state) == TRANS_STATE_BLOCKED) {
+ if (lock && READ_ONCE(cur_trans->state) == TRANS_STATE_BLOCKED) {
if (throttle)
return btrfs_commit_transaction(trans);
else
@@ -1940,7 +1940,7 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans)
int ret;
/* Stop the commit early if ->aborted is set */
- if (unlikely(ACCESS_ONCE(cur_trans->aborted))) {
+ if (unlikely(READ_ONCE(cur_trans->aborted))) {
ret = cur_trans->aborted;
btrfs_end_transaction(trans);
return ret;
@@ -2080,7 +2080,7 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans)
atomic_read(&cur_trans->num_writers) == 1);
/* ->aborted might be set after the previous check, so check it */
- if (unlikely(ACCESS_ONCE(cur_trans->aborted))) {
+ if (unlikely(READ_ONCE(cur_trans->aborted))) {
ret = cur_trans->aborted;
goto scrub_continue;
}
@@ -2194,7 +2194,7 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans)
* The tasks which save the space cache and inode cache may also
* update ->aborted, check it.
*/
- if (unlikely(ACCESS_ONCE(cur_trans->aborted))) {
+ if (unlikely(READ_ONCE(cur_trans->aborted))) {
ret = cur_trans->aborted;
mutex_unlock(&fs_info->tree_log_mutex);
mutex_unlock(&fs_info->reloc_mutex);
diff --git a/fs/btrfs/tree-log.h b/fs/btrfs/tree-log.h
index ab858e31ccbc..127eae01bb1b 100644
--- a/fs/btrfs/tree-log.h
+++ b/fs/btrfs/tree-log.h
@@ -48,13 +48,13 @@ static inline void btrfs_init_log_ctx(struct btrfs_log_ctx *ctx,
static inline void btrfs_set_log_full_commit(struct btrfs_fs_info *fs_info,
struct btrfs_trans_handle *trans)
{
- ACCESS_ONCE(fs_info->last_trans_log_full_commit) = trans->transid;
+ WRITE_ONCE(fs_info->last_trans_log_full_commit, trans->transid);
}
static inline int btrfs_need_log_full_commit(struct btrfs_fs_info *fs_info,
struct btrfs_trans_handle *trans)
{
- return ACCESS_ONCE(fs_info->last_trans_log_full_commit) ==
+ return READ_ONCE(fs_info->last_trans_log_full_commit) ==
trans->transid;
}
--
2.7.4
--
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