diff options
| author | Paolo Bonzini <pbonzini@redhat.com> | 2017-06-05 14:38:54 +0200 |
|---|---|---|
| committer | Fam Zheng <famz@redhat.com> | 2017-06-16 07:55:00 +0800 |
| commit | e2a6ae7fe57c17199624e4d47826ec46ca57d546 (patch) | |
| tree | 081efb61697d284b83fdf40c31195c8da0ac425e | |
| parent | 20fc71b25cfd8102b7f12a2b44133894ad90040a (diff) | |
block: access wakeup with atomic ops
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20170605123908.18777-6-pbonzini@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
| -rw-r--r-- | block/io.c | 3 | ||||
| -rw-r--r-- | block/nfs.c | 4 | ||||
| -rw-r--r-- | block/sheepdog.c | 3 | ||||
| -rw-r--r-- | include/block/block.h | 5 | ||||
| -rw-r--r-- | include/block/block_int.h | 7 |
5 files changed, 15 insertions, 7 deletions
diff --git a/block/io.c b/block/io.c index d76202b452..4a598299a9 100644 --- a/block/io.c +++ b/block/io.c @@ -501,7 +501,8 @@ static void dummy_bh_cb(void *opaque) void bdrv_wakeup(BlockDriverState *bs) { - if (bs->wakeup) { + /* The barrier (or an atomic op) is in the caller. */ + if (atomic_read(&bs->wakeup)) { aio_bh_schedule_oneshot(qemu_get_aio_context(), dummy_bh_cb, NULL); } } diff --git a/block/nfs.c b/block/nfs.c index 848b2c0bb0..18c87d2f25 100644 --- a/block/nfs.c +++ b/block/nfs.c @@ -730,7 +730,9 @@ nfs_get_allocated_file_size_cb(int ret, struct nfs_context *nfs, void *data, if (task->ret < 0) { error_report("NFS Error: %s", nfs_get_error(nfs)); } - task->complete = 1; + + /* Set task->complete before reading bs->wakeup. */ + atomic_mb_set(&task->complete, 1); bdrv_wakeup(task->bs); } diff --git a/block/sheepdog.c b/block/sheepdog.c index a18315a1ca..5ebf5d9fbb 100644 --- a/block/sheepdog.c +++ b/block/sheepdog.c @@ -698,7 +698,8 @@ out: srco->co = NULL; srco->ret = ret; - srco->finished = true; + /* Set srco->finished before reading bs->wakeup. */ + atomic_mb_set(&srco->finished, true); if (srco->bs) { bdrv_wakeup(srco->bs); } diff --git a/include/block/block.h b/include/block/block.h index 9b355e92d8..a4f09df95a 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -402,7 +402,8 @@ void bdrv_drain_all(void); * block_job_defer_to_main_loop for how to do it). \ */ \ assert(!bs_->wakeup); \ - bs_->wakeup = true; \ + /* Set bs->wakeup before evaluating cond. */ \ + atomic_mb_set(&bs_->wakeup, true); \ while (busy_) { \ if ((cond)) { \ waited_ = busy_ = true; \ @@ -414,7 +415,7 @@ void bdrv_drain_all(void); waited_ |= busy_; \ } \ } \ - bs_->wakeup = false; \ + atomic_set(&bs_->wakeup, false); \ } \ waited_; }) diff --git a/include/block/block_int.h b/include/block/block_int.h index 39be34af5c..cf544b7f31 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -604,8 +604,6 @@ struct BlockDriverState { /* Callback before write request is processed */ NotifierWithReturnList before_write_notifiers; - bool wakeup; - /* Offset after the highest byte written to */ uint64_t wr_highest_offset; @@ -636,6 +634,11 @@ struct BlockDriverState { unsigned int in_flight; unsigned int serialising_in_flight; + /* Internal to BDRV_POLL_WHILE and bdrv_wakeup. Accessed with atomic + * ops. + */ + bool wakeup; + /* do we need to tell the quest if we have a volatile write cache? */ int enable_write_cache; |