fuse: make fuse_direct_io() aware about AIO

The patch implements passing "struct fuse_io_priv *io" down the stack up to
fuse_send_read/write where it is used to submit request asynchronously.
io->async==0 designates synchronous processing.

Non-trivial part of the patch is changes in fuse_direct_io(): resources
like fuse requests and user pages cannot be released immediately in async
case.

Signed-off-by: Maxim Patlasov <mpatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>

1 files changed, 4 insertions, 2 deletions

diff --git a/fs/fuse/cuse.c b/fs/fuse/cuse.c
index c59c097eb2e9..b3aaf7b3578b 100644
--- a/fs/fuse/cuse.c
+++ b/fs/fuse/cuse.c
@@ -92,8 +92,9 @@ static ssize_t cuse_read(struct file *file, char __user *buf, size_t count,
 {
         loff_t pos = 0;
         struct iovec iov = { .iov_base = buf, .iov_len = count };
+        struct fuse_io_priv io = { .async = 0, .file = file };
 
-        return fuse_direct_io(file, &iov, 1, count, &pos, 0);
+        return fuse_direct_io(&io, &iov, 1, count, &pos, 0);
 }
 
 static ssize_t cuse_write(struct file *file, const char __user *buf,
@@ -101,12 +102,13 @@ static ssize_t cuse_write(struct file *file, const char __user *buf,
 {
         loff_t pos = 0;
         struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = count };
+        struct fuse_io_priv io = { .async = 0, .file = file };
 
         /*
          * No locking or generic_write_checks(), the server is
          * responsible for locking and sanity checks.
          */
-        return fuse_direct_io(file, &iov, 1, count, &pos, 1);
+        return fuse_direct_io(&io, &iov, 1, count, &pos, 1);
 }
 
 static int cuse_open(struct inode *inode, struct file *file)