We can't dereference the dio structure after submitting the last bio for
this request, as I/O completion might have happened before the code is
run. Introduce a local is_sync variable instead.
Fixes: 542ff7bf ("block: new direct I/O implementation")
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Reported-by: Matias Bjørling <m@xxxxxxxxxxx>
Tested-by: Matias Bjørling <m@xxxxxxxxxxx>
---
fs/block_dev.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 5db5d13..3c47614 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -331,7 +331,7 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages)
struct blk_plug plug;
struct blkdev_dio *dio;
struct bio *bio;
- bool is_read = (iov_iter_rw(iter) == READ);
+ bool is_read = (iov_iter_rw(iter) == READ), is_sync;
loff_t pos = iocb->ki_pos;
blk_qc_t qc = BLK_QC_T_NONE;
int ret;
@@ -344,7 +344,7 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages)
bio_get(bio); /* extra ref for the completion handler */
dio = container_of(bio, struct blkdev_dio, bio);
- dio->is_sync = is_sync_kiocb(iocb);
+ dio->is_sync = is_sync = is_sync_kiocb(iocb);
if (dio->is_sync)
dio->waiter = current;
else
@@ -398,7 +398,7 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages)
}
blk_finish_plug(&plug);
- if (!dio->is_sync)
+ if (!is_sync)
return -EIOCBQUEUED;
for (;;) {
--
2.1.4
--
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