Created
December 17, 2014 06:27
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diff --git a/include/sys/zio.h b/include/sys/zio.h | |
index e10e965..0ba6b65 100644 | |
--- a/include/sys/zio.h | |
+++ b/include/sys/zio.h | |
@@ -383,6 +383,7 @@ typedef struct zio_link { | |
} zio_link_t; | |
struct zio { | |
+ int io_hold; | |
/* Core information about this I/O */ | |
zbookmark_phys_t io_bookmark; | |
zio_prop_t io_prop; | |
diff --git a/module/zfs/zio.c b/module/zfs/zio.c | |
index 9d70b3e..c43355d 100644 | |
--- a/module/zfs/zio.c | |
+++ b/module/zfs/zio.c | |
@@ -1454,6 +1454,11 @@ zio_wait(zio_t *zio) | |
cv_wait_io(&zio->io_cv, &zio->io_lock); | |
mutex_exit(&zio->io_lock); | |
+#ifdef _KERNEL | |
+ while (ACCESS_ONCE(zio->io_hold) != 0) | |
+ cpu_relax(); | |
+#endif | |
+ | |
error = zio->io_error; | |
zio_destroy(zio); | |
@@ -3328,8 +3333,14 @@ zio_done(zio_t *zio) | |
if (zio->io_waiter != NULL) { | |
mutex_enter(&zio->io_lock); | |
zio->io_executor = NULL; | |
+ zio->io_hold = 1; | |
cv_broadcast(&zio->io_cv); | |
mutex_exit(&zio->io_lock); | |
+ /* release hold after we make sure mutex exits */ | |
+#ifdef _KERNEL | |
+ smp_mb(); | |
+#endif | |
+ zio->io_hold = 0; | |
} else { | |
zio_destroy(zio); | |
} |
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