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-rw-r--r--fs/super.c33
1 files changed, 4 insertions, 29 deletions
diff --git a/fs/super.c b/fs/super.c
index a51c2083cd6b..e1fd667454d4 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -1647,36 +1647,11 @@ EXPORT_SYMBOL(__sb_end_write);
*/
int __sb_start_write(struct super_block *sb, int level, bool wait)
{
- bool force_trylock = false;
- int ret = 1;
+ if (!wait)
+ return percpu_down_read_trylock(sb->s_writers.rw_sem + level-1);
-#ifdef CONFIG_LOCKDEP
- /*
- * We want lockdep to tell us about possible deadlocks with freezing
- * but it's it bit tricky to properly instrument it. Getting a freeze
- * protection works as getting a read lock but there are subtle
- * problems. XFS for example gets freeze protection on internal level
- * twice in some cases, which is OK only because we already hold a
- * freeze protection also on higher level. Due to these cases we have
- * to use wait == F (trylock mode) which must not fail.
- */
- if (wait) {
- int i;
-
- for (i = 0; i < level - 1; i++)
- if (percpu_rwsem_is_held(sb->s_writers.rw_sem + i)) {
- force_trylock = true;
- break;
- }
- }
-#endif
- if (wait && !force_trylock)
- percpu_down_read(sb->s_writers.rw_sem + level-1);
- else
- ret = percpu_down_read_trylock(sb->s_writers.rw_sem + level-1);
-
- WARN_ON(force_trylock && !ret);
- return ret;
+ percpu_down_read(sb->s_writers.rw_sem + level-1);
+ return 1;
}
EXPORT_SYMBOL(__sb_start_write);