[PATCH v2] btrfs: don't return EINTR

[Arne Jansen <sensille@gmx.net>]

It is basically a good thing if we are interruptible when waiting for
free space, but the generality in which it is implemented currently
leads to system calls being interruptible that are not documented this
way. For example git can't handle interrupted unlink(), leading to
corrupt repos under space pressure.
Instead we raise the bar to only be interruptible by SIGKILL.
Thanks to David Sterba for suggesting this.

Signed-off-by: Arne Jansen <sensille@gmx.net>
---
 fs/btrfs/extent-tree.c |    9 +++------
 1 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 2b35f8d..10d4bb7 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3769,13 +3769,10 @@ again:
 		 */
 		if (current->journal_info)
 			return -EAGAIN;
-		ret = wait_event_interruptible(space_info->wait,
-					       !space_info->flush);
-		/* Must have been interrupted, return */
-		if (ret) {
-			printk(KERN_DEBUG "btrfs: %s returning -EINTR\n", __func__);
+		ret = wait_event_killable(space_info->wait, !space_info->flush);
+		/* Must have been killed, return */
+		if (ret)
 			return -EINTR;
-		}
 
 		spin_lock(&space_info->lock);
 	}
-- 
1.7.3.4