Subject: [PATCH] fuse: relax inode_lock on fsync(2)
From: Maxim Patlasov <mpatlasov@virtuozzo.com>
To: <miklos@szeredi.hu>
CC: <linux-fsdevel@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <mpatlasov@virtuozzo.com>
Date: Tue, 13 Dec 2016 16:42:49 -0800
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Sometimes handling FUSE_FSYNC in userspace may take a while. No need
to block incoming writes while userspace processes FUSE_FSYNC.

Signed-off-by: Maxim Patlasov <mpatlasov@virtuozzo.com>
---
 fs/fuse/file.c |    3 +++
 1 file changed, 3 insertions(+)

diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 2401c5d..9d52a8a 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -483,6 +483,8 @@ int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
 	if ((!isdir && fc->no_fsync) || (isdir && fc->no_fsyncdir))
 		goto out;
 
+	inode_unlock(inode);
+
 	memset(&inarg, 0, sizeof(inarg));
 	inarg.fh = ff->fh;
 	inarg.fsync_flags = datasync ? 1 : 0;
@@ -499,6 +501,7 @@ int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
 			fc->no_fsync = 1;
 		err = 0;
 	}
+	return err;
 out:
 	inode_unlock(inode);
 	return err;