*
* Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
* Copyright 1999-2000 Jeremy Fitzhardinge <jeremy@goop.org>
- * Copyright 2001-2003 Ian Kent <raven@themaw.net>
+ * Copyright 2001-2006 Ian Kent <raven@themaw.net>
*
* This file is part of the Linux kernel and is made available under
* the terms of the GNU General Public License, version 2, or at your
/* Check a mount point for busyness */
static int autofs4_mount_busy(struct vfsmount *mnt, struct dentry *dentry)
{
+ struct dentry *top = dentry;
int status = 1;
DPRINTK("dentry %p %.*s",
if (is_autofs4_dentry(dentry))
goto done;
- /* The big question */
- if (may_umount_tree(mnt) == 0)
- status = 0;
+ /* Update the expiry counter if fs is busy */
+ if (!may_umount_tree(mnt)) {
+ struct autofs_info *ino = autofs4_dentry_ino(top);
+ ino->last_used = jiffies;
+ goto done;
+ }
+
+ status = 0;
done:
DPRINTK("returning = %d", status);
mntput(mnt);
return list_entry(next, struct dentry, d_u.d_child);
}
+/*
+ * Check a direct mount point for busyness.
+ * Direct mounts have similar expiry semantics to tree mounts.
+ * The tree is not busy iff no mountpoints are busy and there are no
+ * autofs submounts.
+ */
+static int autofs4_direct_busy(struct vfsmount *mnt,
+ struct dentry *top,
+ unsigned long timeout,
+ int do_now)
+{
+ DPRINTK("top %p %.*s",
+ top, (int) top->d_name.len, top->d_name.name);
+
+ /* If it's busy update the expiry counters */
+ if (!may_umount_tree(mnt)) {
+ struct autofs_info *ino = autofs4_dentry_ino(top);
+ if (ino)
+ ino->last_used = jiffies;
+ return 1;
+ }
+
+ /* Timeout of a direct mount is determined by its top dentry */
+ if (!autofs4_can_expire(top, timeout, do_now))
+ return 1;
+
+ return 0;
+}
+
/* Check a directory tree of mount points for busyness
* The tree is not busy iff no mountpoints are busy
*/
unsigned long timeout,
int do_now)
{
- struct autofs_info *ino;
+ struct autofs_info *top_ino = autofs4_dentry_ino(top);
struct dentry *p;
DPRINTK("top %p %.*s",
* Is someone visiting anywhere in the subtree ?
* If there's no mount we need to check the usage
* count for the autofs dentry.
+ * If the fs is busy update the expiry counter.
*/
- ino = autofs4_dentry_ino(p);
if (d_mountpoint(p)) {
if (autofs4_mount_busy(mnt, p)) {
+ top_ino->last_used = jiffies;
dput(p);
return 1;
}
} else {
+ struct autofs_info *ino = autofs4_dentry_ino(p);
unsigned int ino_count = atomic_read(&ino->count);
/* allow for dget above and top is already dgot */
ino_count++;
if (atomic_read(&p->d_count) > ino_count) {
+ top_ino->last_used = jiffies;
dput(p);
return 1;
}
spin_unlock(&dcache_lock);
if (d_mountpoint(p)) {
- /* Can we expire this guy */
- if (!autofs4_can_expire(p, timeout, do_now))
+ /* Can we umount this guy */
+ if (autofs4_mount_busy(mnt, p))
goto cont;
- /* Can we umount this guy */
- if (!autofs4_mount_busy(mnt, p))
+ /* Can we expire this guy */
+ if (autofs4_can_expire(p, timeout, do_now))
return p;
-
}
cont:
dput(p);
return NULL;
}
+/* Check if we can expire a direct mount (possibly a tree) */
+static struct dentry *autofs4_expire_direct(struct super_block *sb,
+ struct vfsmount *mnt,
+ struct autofs_sb_info *sbi,
+ int how)
+{
+ unsigned long timeout;
+ struct dentry *root = dget(sb->s_root);
+ int do_now = how & AUTOFS_EXP_IMMEDIATE;
+
+ if (!sbi->exp_timeout || !root)
+ return NULL;
+
+ now = jiffies;
+ timeout = sbi->exp_timeout;
+
+ /* Lock the tree as we must expire as a whole */
+ spin_lock(&sbi->fs_lock);
+ if (!autofs4_direct_busy(mnt, root, timeout, do_now)) {
+ struct autofs_info *ino = autofs4_dentry_ino(root);
+
+ /* Set this flag early to catch sys_chdir and the like */
+ ino->flags |= AUTOFS_INF_EXPIRING;
+ spin_unlock(&sbi->fs_lock);
+ return root;
+ }
+ spin_unlock(&sbi->fs_lock);
+ dput(root);
+
+ return NULL;
+}
+
/*
* Find an eligible tree to time-out
* A tree is eligible if :-
* - it is unused by any user process
* - it has been unused for exp_timeout time
*/
-static struct dentry *autofs4_expire(struct super_block *sb,
- struct vfsmount *mnt,
- struct autofs_sb_info *sbi,
- int how)
+static struct dentry *autofs4_expire_indirect(struct super_block *sb,
+ struct vfsmount *mnt,
+ struct autofs_sb_info *sbi,
+ int how)
{
unsigned long timeout;
struct dentry *root = sb->s_root;
dentry = dget(dentry);
spin_unlock(&dcache_lock);
- /* Case 1: indirect mount or top level direct mount */
+ /*
+ * Case 1: (i) indirect mount or top level pseudo direct mount
+ * (autofs-4.1).
+ * (ii) indirect mount with offset mount, check the "/"
+ * offset (autofs-5.0+).
+ */
if (d_mountpoint(dentry)) {
DPRINTK("checking mountpoint %p %.*s",
dentry, (int)dentry->d_name.len, dentry->d_name.name);
- /* Can we expire this guy */
- if (!autofs4_can_expire(dentry, timeout, do_now))
+ /* Can we umount this guy */
+ if (autofs4_mount_busy(mnt, dentry))
goto next;
- /* Can we umount this guy */
- if (!autofs4_mount_busy(mnt, dentry)) {
+ /* Can we expire this guy */
+ if (autofs4_can_expire(dentry, timeout, do_now)) {
expired = dentry;
break;
}
break;
}
spin_unlock(&sbi->fs_lock);
- /* Case 3: direct mount, expire individual leaves */
+ /*
+ * Case 3: pseudo direct mount, expire individual leaves
+ * (autofs-4.1).
+ */
} else {
expired = autofs4_check_leaves(mnt, dentry, timeout, do_now);
if (expired) {
pkt.hdr.proto_version = sbi->version;
pkt.hdr.type = autofs_ptype_expire;
- if ((dentry = autofs4_expire(sb, mnt, sbi, 0)) == NULL)
+ if ((dentry = autofs4_expire_indirect(sb, mnt, sbi, 0)) == NULL)
return -EAGAIN;
pkt.len = dentry->d_name.len;
if (arg && get_user(do_now, arg))
return -EFAULT;
- if ((dentry = autofs4_expire(sb, mnt, sbi, do_now)) != NULL) {
+ if (sbi->type & AUTOFS_TYPE_DIRECT)
+ dentry = autofs4_expire_direct(sb, mnt, sbi, do_now);
+ else
+ dentry = autofs4_expire_indirect(sb, mnt, sbi, do_now);
+
+ if (dentry) {
struct autofs_info *ino = autofs4_dentry_ino(dentry);
/* This is synchronous because it makes the daemon a