diff options
| -rw-r--r-- | fs/autofs4/expire.c | 96 |
1 files changed, 87 insertions, 9 deletions
diff --git a/fs/autofs4/expire.c b/fs/autofs4/expire.c index 02a218fbde5..8fd92eaf936 100644 --- a/fs/autofs4/expire.c +++ b/fs/autofs4/expire.c @@ -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 @@ cont: 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 |