提交 3a15e2ab 编写于 作者: I Ian Kent 提交者: Linus Torvalds

[PATCH] autofs4: add v5 expire logic

This patch adds expire logic for autofs direct mounts.
Signed-off-by: NIan Kent <raven@themaw.net>
Cc: Al Viro <viro@ftp.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
上级 34ca959c
......@@ -4,7 +4,7 @@
*
* 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
......@@ -99,6 +99,39 @@ static struct dentry *next_dentry(struct dentry *p, struct dentry *root)
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);
/* Not a mountpoint - give up */
if (!d_mountpoint(top))
return 1;
/* 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
*/
......@@ -208,16 +241,48 @@ static struct dentry *autofs4_check_leaves(struct vfsmount *mnt,
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;
......@@ -249,7 +314,12 @@ static struct dentry *autofs4_expire(struct super_block *sb,
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);
......@@ -283,7 +353,10 @@ static struct dentry *autofs4_expire(struct super_block *sb,
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) {
......@@ -325,7 +398,7 @@ int autofs4_expire_run(struct super_block *sb,
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;
......@@ -351,7 +424,12 @@ int autofs4_expire_multi(struct super_block *sb, struct vfsmount *mnt,
if (arg && get_user(do_now, arg))
return -EFAULT;
if ((dentry = autofs4_expire(sb, mnt, sbi, do_now)) != NULL) {
if (sbi->type & AUTOFS_TYP_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
......
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