[PATCH] fuse: add O_NONBLOCK support to FUSE device

I don't like duplicating the connected and list_empty tests in fuse_dev_readv,
but this seemed cleaner than adding the f_flags test to request_wait.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 6 insertions, 0 deletions

diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index 438770f8867f..75c6e9166c39 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -619,6 +619,12 @@ static ssize_t fuse_dev_readv(struct file *file, const struct iovec *iov,
         err = -EPERM;
         if (!fc)
                 goto err_unlock;
+
+        err = -EAGAIN;
+        if ((file->f_flags & O_NONBLOCK) && fc->connected &&
+            list_empty(&fc->pending))
+                goto err_unlock;
+
         request_wait(fc);
         err = -ENODEV;
         if (!fc->connected)