From 56fe4a3d6e803143814fc27866dac94252104d7e Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Mon, 26 Feb 2018 12:51:43 +0100 Subject: [PATCH] direct-io: Fix sleep in atomic due to sync AIO Commit ecbcbc0678f0 "fs: add RWF_DSYNC aand RWF_SYNC" added additional way for direct IO to become synchronous and thus trigger fsync from the IO completion handler. Then commit 884d5a96cd3a "fs: Use RWF_* flags for AIO operations" allowed these flags to be set for AIO as well. However that commit forgot to update the condition checking whether the IO completion handling should be defered to a workqueue and thus AIO DIO with RWF_[D]SYNC set will call fsync() from IRQ context resulting in sleep in atomic. Fix the problem by checking directly iocb flags (the same way as it is done in dio_complete()) instead of checking all conditions that could lead to IO being synchronous. CC: Christoph Hellwig CC: Goldwyn Rodrigues CC: stable@vger.kernel.org Reported-by: Mark Rutland Tested-by: Mark Rutland Fixes: 884d5a96cd3ad33c5e667a838cbd7d5dc5bb5833 Signed-off-by: Jan Kara Signed-off-by: Jens Axboe --- fs/direct-io.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/fs/direct-io.c b/fs/direct-io.c index a0ca9e48e9937..1357ef563893a 100644 --- a/fs/direct-io.c +++ b/fs/direct-io.c @@ -1274,8 +1274,7 @@ do_blockdev_direct_IO(struct kiocb *iocb, struct inode *inode, */ if (dio->is_async && iov_iter_rw(iter) == WRITE) { retval = 0; - if ((iocb->ki_filp->f_flags & O_DSYNC) || - IS_SYNC(iocb->ki_filp->f_mapping->host)) + if (iocb->ki_flags & IOCB_DSYNC) retval = dio_set_defer_completion(dio); else if (!dio->inode->i_sb->s_dio_done_wq) { /* -- 2.39.5