[PATCH 3.15 23/37] fuse: add FUSE_NO_OPEN_SUPPORT flag to INIT

Greg Kroah-Hartman
2014-07-30T01:48:59Z

From: Andrew Gallagher <andrewjcg@fb.com>

commit d7afaec0b564f0609e116f562983b8e72fc3e9c9 upstream.

Here some additional changes to set a capability flag so that clients can
detect when it's appropriate to return -ENOSYS from open.

This amends the following commit introduced in 3.14:

7678ac50615d fuse: support clients that don't implement 'open'

However we can only add the flag to 3.15 and later since there was no
protocol version update in 3.14.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/fuse/inode.c | 2 +-
include/uapi/linux/fuse.h | 3 +++
2 files changed, 4 insertions(+), 1 deletion(-)

--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -935,7 +935,7 @@ static void fuse_send_init(struct fuse_c
FUSE_SPLICE_WRITE | FUSE_SPLICE_MOVE | FUSE_SPLICE_READ |
FUSE_FLOCK_LOCKS | FUSE_IOCTL_DIR | FUSE_AUTO_INVAL_DATA |
FUSE_DO_READDIRPLUS | FUSE_READDIRPLUS_AUTO | FUSE_ASYNC_DIO |
- FUSE_WRITEBACK_CACHE;
+ FUSE_WRITEBACK_CACHE | FUSE_NO_OPEN_SUPPORT;
req->in.h.opcode = FUSE_INIT;
req->in.numargs = 1;
req->in.args[0].size = sizeof(*arg);
--- a/include/uapi/linux/fuse.h
+++ b/include/uapi/linux/fuse.h
@@ -101,6 +101,7 @@
* - add FATTR_CTIME
* - add ctime and ctimensec to fuse_setattr_in
* - add FUSE_RENAME2 request
+ * - add FUSE_NO_OPEN_SUPPORT flag
*/

#ifndef _LINUX_FUSE_H
@@ -229,6 +230,7 @@ struct fuse_file_lock {
* FUSE_READDIRPLUS_AUTO: adaptive readdirplus
* FUSE_ASYNC_DIO: asynchronous direct I/O submission
* FUSE_WRITEBACK_CACHE: use writeback cache for buffered writes
+ * FUSE_NO_OPEN_SUPPORT: kernel supports zero-message opens
*/
#define FUSE_ASYNC_READ (1 << 0)
#define FUSE_POSIX_LOCKS (1 << 1)
@@ -247,6 +249,7 @@ struct fuse_file_lock {
#define FUSE_READDIRPLUS_AUTO (1 << 14)
#define FUSE_ASYNC_DIO (1 << 15)
#define FUSE_WRITEBACK_CACHE (1 << 16)
+#define FUSE_NO_OPEN_SUPPORT (1 << 17)

/**
* CUSE INIT request/reply flags