diff options
author | Eric W. Biederman <ebiederm@xmission.com> | 2007-12-01 13:33:17 (GMT) |
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committer | Herbert Xu <herbert@gondor.apana.org.au> | 2007-12-01 13:33:17 (GMT) |
commit | 2b1e300a9dfc3196ccddf6f1d74b91b7af55e416 (patch) | |
tree | 3181bf4f2c27d185c78b26642f35ed00cb280943 /fs/proc/proc_net.c | |
parent | e03ba84adb62fbc6049325a5bc00ef6932fa5e39 (diff) | |
download | linux-2b1e300a9dfc3196ccddf6f1d74b91b7af55e416.tar.xz |
[NETNS]: Fix /proc/net breakage
Well I clearly goofed when I added the initial network namespace support
for /proc/net. Currently things work but there are odd details visible to
user space, even when we have a single network namespace.
Since we do not cache proc_dir_entry dentries at the moment we can just
modify ->lookup to return a different directory inode depending on the
network namespace of the process looking at /proc/net, replacing the
current technique of using a magic and fragile follow_link method.
To accomplish that this patch:
- introduces a shadow_proc method to allow different dentries to
be returned from proc_lookup.
- Removes the old /proc/net follow_link magic
- Fixes a weakness in our not caching of proc generic dentries.
As shadow_proc uses a task struct to decided which dentry to return we can
go back later and fix the proc generic caching without modifying any code
that uses the shadow_proc method.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'fs/proc/proc_net.c')
-rw-r--r-- | fs/proc/proc_net.c | 86 |
1 files changed, 5 insertions, 81 deletions
diff --git a/fs/proc/proc_net.c b/fs/proc/proc_net.c index 131f9c6..0afe21e 100644 --- a/fs/proc/proc_net.c +++ b/fs/proc/proc_net.c @@ -50,89 +50,14 @@ struct net *get_proc_net(const struct inode *inode) } EXPORT_SYMBOL_GPL(get_proc_net); -static struct proc_dir_entry *proc_net_shadow; +static struct proc_dir_entry *shadow_pde; -static struct dentry *proc_net_shadow_dentry(struct dentry *parent, +static struct proc_dir_entry *proc_net_shadow(struct task_struct *task, struct proc_dir_entry *de) { - struct dentry *shadow = NULL; - struct inode *inode; - if (!de) - goto out; - de_get(de); - inode = proc_get_inode(parent->d_inode->i_sb, de->low_ino, de); - if (!inode) - goto out_de_put; - shadow = d_alloc_name(parent, de->name); - if (!shadow) - goto out_iput; - shadow->d_op = parent->d_op; /* proc_dentry_operations */ - d_instantiate(shadow, inode); -out: - return shadow; -out_iput: - iput(inode); -out_de_put: - de_put(de); - goto out; -} - -static void *proc_net_follow_link(struct dentry *parent, struct nameidata *nd) -{ - struct net *net = current->nsproxy->net_ns; - struct dentry *shadow; - shadow = proc_net_shadow_dentry(parent, net->proc_net); - if (!shadow) - return ERR_PTR(-ENOENT); - - dput(nd->dentry); - /* My dentry count is 1 and that should be enough as the - * shadow dentry is thrown away immediately. - */ - nd->dentry = shadow; - return NULL; + return task->nsproxy->net_ns->proc_net; } -static struct dentry *proc_net_lookup(struct inode *dir, struct dentry *dentry, - struct nameidata *nd) -{ - struct net *net = current->nsproxy->net_ns; - struct dentry *shadow; - - shadow = proc_net_shadow_dentry(nd->dentry, net->proc_net); - if (!shadow) - return ERR_PTR(-ENOENT); - - dput(nd->dentry); - nd->dentry = shadow; - - return shadow->d_inode->i_op->lookup(shadow->d_inode, dentry, nd); -} - -static int proc_net_setattr(struct dentry *dentry, struct iattr *iattr) -{ - struct net *net = current->nsproxy->net_ns; - struct dentry *shadow; - int ret; - - shadow = proc_net_shadow_dentry(dentry->d_parent, net->proc_net); - if (!shadow) - return -ENOENT; - ret = shadow->d_inode->i_op->setattr(shadow, iattr); - dput(shadow); - return ret; -} - -static const struct file_operations proc_net_dir_operations = { - .read = generic_read_dir, -}; - -static struct inode_operations proc_net_dir_inode_operations = { - .follow_link = proc_net_follow_link, - .lookup = proc_net_lookup, - .setattr = proc_net_setattr, -}; - static __net_init int proc_net_ns_init(struct net *net) { struct proc_dir_entry *root, *netd, *net_statd; @@ -185,9 +110,8 @@ static struct pernet_operations __net_initdata proc_net_ns_ops = { int __init proc_net_init(void) { - proc_net_shadow = proc_mkdir("net", NULL); - proc_net_shadow->proc_iops = &proc_net_dir_inode_operations; - proc_net_shadow->proc_fops = &proc_net_dir_operations; + shadow_pde = proc_mkdir("net", NULL); + shadow_pde->shadow_proc = proc_net_shadow; return register_pernet_subsys(&proc_net_ns_ops); } |