[PATCH] AUTOFS: Make sure all dentries refs are released before calling kill_anon_super()

Make sure all dentries refs are released before calling kill_anon_super() so
that the assumption that generic_shutdown_super() can completely destroy the
dentry tree for there will be no external references holds true.

What was being done in the put_super() superblock op, is now done in the
kill_sb() filesystem op instead, prior to calling kill_anon_super().

This makes the struct autofs_sb_info::root member variable redundant (since
sb->s_root is still available), and so that is removed.  The calls to
shrink_dcache_sb() are also removed since they're also redundant as
shrink_dcache_for_umount() will now be called after the cleanup routine.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Ian Kent <raven@themaw.net>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
David Howells 2006-10-11 01:22:15 -07:00 committed by Linus Torvalds
parent edc666e2ff
commit 6ce315234a
4 changed files with 6 additions and 22 deletions

View file

@ -94,7 +94,6 @@ struct autofs_wait_queue {
struct autofs_sb_info {
u32 magic;
struct dentry *root;
int pipefd;
struct file *pipe;
pid_t oz_pgrp;
@ -229,4 +228,4 @@ out:
}
void autofs4_dentry_release(struct dentry *);
extern void autofs4_kill_sb(struct super_block *);

View file

@ -24,7 +24,7 @@ static struct file_system_type autofs_fs_type = {
.owner = THIS_MODULE,
.name = "autofs",
.get_sb = autofs_get_sb,
.kill_sb = kill_anon_super,
.kill_sb = autofs4_kill_sb,
};
static int __init init_autofs4_fs(void)

View file

@ -96,7 +96,7 @@ void autofs4_free_ino(struct autofs_info *ino)
*/
static void autofs4_force_release(struct autofs_sb_info *sbi)
{
struct dentry *this_parent = sbi->root;
struct dentry *this_parent = sbi->sb->s_root;
struct list_head *next;
spin_lock(&dcache_lock);
@ -127,7 +127,7 @@ resume:
spin_lock(&dcache_lock);
}
if (this_parent != sbi->root) {
if (this_parent != sbi->sb->s_root) {
struct dentry *dentry = this_parent;
next = this_parent->d_u.d_child.next;
@ -140,15 +140,9 @@ resume:
goto resume;
}
spin_unlock(&dcache_lock);
dput(sbi->root);
sbi->root = NULL;
shrink_dcache_sb(sbi->sb);
return;
}
static void autofs4_put_super(struct super_block *sb)
void autofs4_kill_sb(struct super_block *sb)
{
struct autofs_sb_info *sbi = autofs4_sbi(sb);
@ -163,6 +157,7 @@ static void autofs4_put_super(struct super_block *sb)
kfree(sbi);
DPRINTK("shutting down");
kill_anon_super(sb);
}
static int autofs4_show_options(struct seq_file *m, struct vfsmount *mnt)
@ -189,7 +184,6 @@ static int autofs4_show_options(struct seq_file *m, struct vfsmount *mnt)
}
static struct super_operations autofs4_sops = {
.put_super = autofs4_put_super,
.statfs = simple_statfs,
.show_options = autofs4_show_options,
};
@ -315,7 +309,6 @@ int autofs4_fill_super(struct super_block *s, void *data, int silent)
s->s_fs_info = sbi;
sbi->magic = AUTOFS_SBI_MAGIC;
sbi->root = NULL;
sbi->pipefd = -1;
sbi->catatonic = 0;
sbi->exp_timeout = 0;
@ -396,13 +389,6 @@ int autofs4_fill_super(struct super_block *s, void *data, int silent)
sbi->pipe = pipe;
sbi->pipefd = pipefd;
/*
* Take a reference to the root dentry so we get a chance to
* clean up the dentry tree on umount.
* See autofs4_force_release.
*/
sbi->root = dget(root);
/*
* Success! Install the root dentry now to indicate completion.
*/

View file

@ -45,7 +45,6 @@ void autofs4_catatonic_mode(struct autofs_sb_info *sbi)
fput(sbi->pipe); /* Close the pipe */
sbi->pipe = NULL;
}
shrink_dcache_sb(sbi->sb);
}
static int autofs4_write(struct file *file, const void *addr, int bytes)