From: Ian Kent <raven@themaw.net>
Add ioctl to find out if autofs mount can be umounted. When the daemon
discovers this it's past the point of no return.
---
25-akpm/fs/autofs4/root.c | 20 ++++++++++++++++++++
25-akpm/include/linux/auto_fs4.h | 1 +
2 files changed, 21 insertions(+)
diff -puN fs/autofs4/root.c~6-autofs4-2.6.0-may_umount-20040405 fs/autofs4/root.c
--- 25/fs/autofs4/root.c~6-autofs4-2.6.0-may_umount-20040405 2004-04-18 15:35:22.324205128 -0700
+++ 25-akpm/fs/autofs4/root.c 2004-04-18 15:35:22.329204368 -0700
@@ -662,6 +662,23 @@ static inline int autofs4_get_protosubve
return put_user(sbi->sub_version, p);
}
+/*
+* Tells the daemon whether it can umount the autofs mount.
+*/
+static inline int autofs4_ask_umount(struct vfsmount *mnt, int *p)
+{
+ int status = 0;
+
+ if (may_umount(mnt) == 0)
+ status = 1;
+
+ DPRINTK(("autofs_ask_umount: returning %d\n", status));
+
+ status = put_user(status, p);
+
+ return status;
+}
+
/* Identify autofs4_dentries - this is so we can tell if there's
an extra dentry refcount or not. We only hold a refcount on the
dentry if its non-negative (ie, d_inode != NULL)
@@ -708,6 +725,9 @@ static int autofs4_root_ioctl(struct ino
case AUTOFS_IOC_SETTIMEOUT:
return autofs4_get_set_timeout(sbi,(unsigned long *)arg);
+ case AUTOFS_IOC_ASKUMOUNT:
+ return autofs4_ask_umount(filp->f_vfsmnt, (int *) arg);
+
/* return a single thing to expire */
case AUTOFS_IOC_EXPIRE:
return autofs4_expire_run(inode->i_sb,filp->f_vfsmnt,sbi,
diff -puN include/linux/auto_fs4.h~6-autofs4-2.6.0-may_umount-20040405 include/linux/auto_fs4.h
--- 25/include/linux/auto_fs4.h~6-autofs4-2.6.0-may_umount-20040405 2004-04-18 15:35:22.326204824 -0700
+++ 25-akpm/include/linux/auto_fs4.h 2004-04-18 15:35:22.330204216 -0700
@@ -49,6 +49,7 @@ union autofs_packet_union {
#define AUTOFS_IOC_EXPIRE_MULTI _IOW(0x93,0x66,int)
#define AUTOFS_IOC_PROTOSUBVER _IOR(0x93,0x67,int)
+#define AUTOFS_IOC_ASKUMOUNT _IOR(0x93,0x70,int)
#endif /* _LINUX_AUTO_FS4_H */
_