fuse: return -ECONNABORTED on /dev/fuse read after abort

Currently the userspace has no way of knowing whether the fuse
connection ended because of umount or abort via sysfs. It makes it hard
for filesystems to free the mountpoint after abort without worrying
about removing some new mount.

The patch fixes it by returning different errors when userspace reads
from /dev/fuse (-ENODEV for umount and -ECONNABORTED for abort).

Add a new capability flag FUSE_ABORT_ERROR. If set and the connection is
gone because of sysfs abort, reading from the device will return
-ECONNABORTED.

Signed-off-by: Szymon Lukasz <noh4hss@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
This commit is contained in:
Szymon Lukasz
2017-11-09 21:23:35 +01:00
committed by Miklos Szeredi
parent df0e91d488
commit 3b7008b226
6 changed files with 29 additions and 13 deletions

View File

@@ -113,6 +113,9 @@
* 7.26
* - add FUSE_HANDLE_KILLPRIV
* - add FUSE_POSIX_ACL
*
* 7.27
* - add FUSE_ABORT_ERROR
*/
#ifndef _LINUX_FUSE_H
@@ -148,7 +151,7 @@
#define FUSE_KERNEL_VERSION 7
/** Minor version number of this interface */
#define FUSE_KERNEL_MINOR_VERSION 26
#define FUSE_KERNEL_MINOR_VERSION 27
/** The node ID of the root inode */
#define FUSE_ROOT_ID 1
@@ -245,6 +248,7 @@ struct fuse_file_lock {
* FUSE_PARALLEL_DIROPS: allow parallel lookups and readdir
* FUSE_HANDLE_KILLPRIV: fs handles killing suid/sgid/cap on write/chown/trunc
* FUSE_POSIX_ACL: filesystem supports posix acls
* FUSE_ABORT_ERROR: reading the device after abort returns ECONNABORTED
*/
#define FUSE_ASYNC_READ (1 << 0)
#define FUSE_POSIX_LOCKS (1 << 1)
@@ -267,6 +271,7 @@ struct fuse_file_lock {
#define FUSE_PARALLEL_DIROPS (1 << 18)
#define FUSE_HANDLE_KILLPRIV (1 << 19)
#define FUSE_POSIX_ACL (1 << 20)
#define FUSE_ABORT_ERROR (1 << 21)
/**
* CUSE INIT request/reply flags