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authorLinus Torvalds <torvalds@linux-foundation.org>2014-08-09 17:10:41 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-08-09 17:10:41 -0700
commit77e40aae766ccbbbb0324cb92ab22e6e998375d7 (patch)
treefb4e8e840aaeeaac62249d7585249c4634886baa /fs/nfs
parent96784de59fb35077c2bb33c39328992b836d87d3 (diff)
parent344470cac42e887e68cfb5bdfa6171baf27f1eb5 (diff)
downloadlinux-77e40aae766ccbbbb0324cb92ab22e6e998375d7.tar.bz2
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull namespace updates from Eric Biederman: "This is a bunch of small changes built against 3.16-rc6. The most significant change for users is the first patch which makes setns drmatically faster by removing unneded rcu handling. The next chunk of changes are so that "mount -o remount,.." will not allow the user namespace root to drop flags on a mount set by the system wide root. Aks this forces read-only mounts to stay read-only, no-dev mounts to stay no-dev, no-suid mounts to stay no-suid, no-exec mounts to stay no exec and it prevents unprivileged users from messing with a mounts atime settings. I have included my test case as the last patch in this series so people performing backports can verify this change works correctly. The next change fixes a bug in NFS that was discovered while auditing nsproxy users for the first optimization. Today you can oops the kernel by reading /proc/fs/nfsfs/{servers,volumes} if you are clever with pid namespaces. I rebased and fixed the build of the !CONFIG_NFS_FS case yesterday when a build bot caught my typo. Given that no one to my knowledge bases anything on my tree fixing the typo in place seems more responsible that requiring a typo-fix to be backported as well. The last change is a small semantic cleanup introducing /proc/thread-self and pointing /proc/mounts and /proc/net at it. This prevents several kinds of problemantic corner cases. It is a user-visible change so it has a minute chance of causing regressions so the change to /proc/mounts and /proc/net are individual one line commits that can be trivially reverted. Unfortunately I lost and could not find the email of the original reporter so he is not credited. From at least one perspective this change to /proc/net is a refgression fix to allow pthread /proc/net uses that were broken by the introduction of the network namespace" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: proc: Point /proc/mounts at /proc/thread-self/mounts instead of /proc/self/mounts proc: Point /proc/net at /proc/thread-self/net instead of /proc/self/net proc: Implement /proc/thread-self to point at the directory of the current thread proc: Have net show up under /proc/<tgid>/task/<tid> NFS: Fix /proc/fs/nfsfs/servers and /proc/fs/nfsfs/volumes mnt: Add tests for unprivileged remount cases that have found to be faulty mnt: Change the default remount atime from relatime to the existing value mnt: Correct permission checks in do_remount mnt: Move the test for MNT_LOCK_READONLY from change_mount_flags into do_remount mnt: Only change user settable mount flags in remount namespaces: Use task_lock and not rcu to protect nsproxy
Diffstat (limited to 'fs/nfs')
-rw-r--r--fs/nfs/client.c95
-rw-r--r--fs/nfs/inode.c3
-rw-r--r--fs/nfs/internal.h9
-rw-r--r--fs/nfs/netns.h3
4 files changed, 69 insertions, 41 deletions
diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 1d09289c8f0e..180d1ec9c32e 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -1205,7 +1205,7 @@ static const struct file_operations nfs_server_list_fops = {
.open = nfs_server_list_open,
.read = seq_read,
.llseek = seq_lseek,
- .release = seq_release,
+ .release = seq_release_net,
.owner = THIS_MODULE,
};
@@ -1226,7 +1226,7 @@ static const struct file_operations nfs_volume_list_fops = {
.open = nfs_volume_list_open,
.read = seq_read,
.llseek = seq_lseek,
- .release = seq_release,
+ .release = seq_release_net,
.owner = THIS_MODULE,
};
@@ -1236,19 +1236,8 @@ static const struct file_operations nfs_volume_list_fops = {
*/
static int nfs_server_list_open(struct inode *inode, struct file *file)
{
- struct seq_file *m;
- int ret;
- struct pid_namespace *pid_ns = file->f_dentry->d_sb->s_fs_info;
- struct net *net = pid_ns->child_reaper->nsproxy->net_ns;
-
- ret = seq_open(file, &nfs_server_list_ops);
- if (ret < 0)
- return ret;
-
- m = file->private_data;
- m->private = net;
-
- return 0;
+ return seq_open_net(inode, file, &nfs_server_list_ops,
+ sizeof(struct seq_net_private));
}
/*
@@ -1256,7 +1245,7 @@ static int nfs_server_list_open(struct inode *inode, struct file *file)
*/
static void *nfs_server_list_start(struct seq_file *m, loff_t *_pos)
{
- struct nfs_net *nn = net_generic(m->private, nfs_net_id);
+ struct nfs_net *nn = net_generic(seq_file_net(m), nfs_net_id);
/* lock the list against modification */
spin_lock(&nn->nfs_client_lock);
@@ -1268,7 +1257,7 @@ static void *nfs_server_list_start(struct seq_file *m, loff_t *_pos)
*/
static void *nfs_server_list_next(struct seq_file *p, void *v, loff_t *pos)
{
- struct nfs_net *nn = net_generic(p->private, nfs_net_id);
+ struct nfs_net *nn = net_generic(seq_file_net(p), nfs_net_id);
return seq_list_next(v, &nn->nfs_client_list, pos);
}
@@ -1278,7 +1267,7 @@ static void *nfs_server_list_next(struct seq_file *p, void *v, loff_t *pos)
*/
static void nfs_server_list_stop(struct seq_file *p, void *v)
{
- struct nfs_net *nn = net_generic(p->private, nfs_net_id);
+ struct nfs_net *nn = net_generic(seq_file_net(p), nfs_net_id);
spin_unlock(&nn->nfs_client_lock);
}
@@ -1289,7 +1278,7 @@ static void nfs_server_list_stop(struct seq_file *p, void *v)
static int nfs_server_list_show(struct seq_file *m, void *v)
{
struct nfs_client *clp;
- struct nfs_net *nn = net_generic(m->private, nfs_net_id);
+ struct nfs_net *nn = net_generic(seq_file_net(m), nfs_net_id);
/* display header on line 1 */
if (v == &nn->nfs_client_list) {
@@ -1321,19 +1310,8 @@ static int nfs_server_list_show(struct seq_file *m, void *v)
*/
static int nfs_volume_list_open(struct inode *inode, struct file *file)
{
- struct seq_file *m;
- int ret;
- struct pid_namespace *pid_ns = file->f_dentry->d_sb->s_fs_info;
- struct net *net = pid_ns->child_reaper->nsproxy->net_ns;
-
- ret = seq_open(file, &nfs_volume_list_ops);
- if (ret < 0)
- return ret;
-
- m = file->private_data;
- m->private = net;
-
- return 0;
+ return seq_open_net(inode, file, &nfs_server_list_ops,
+ sizeof(struct seq_net_private));
}
/*
@@ -1341,7 +1319,7 @@ static int nfs_volume_list_open(struct inode *inode, struct file *file)
*/
static void *nfs_volume_list_start(struct seq_file *m, loff_t *_pos)
{
- struct nfs_net *nn = net_generic(m->private, nfs_net_id);
+ struct nfs_net *nn = net_generic(seq_file_net(m), nfs_net_id);
/* lock the list against modification */
spin_lock(&nn->nfs_client_lock);
@@ -1353,7 +1331,7 @@ static void *nfs_volume_list_start(struct seq_file *m, loff_t *_pos)
*/
static void *nfs_volume_list_next(struct seq_file *p, void *v, loff_t *pos)
{
- struct nfs_net *nn = net_generic(p->private, nfs_net_id);
+ struct nfs_net *nn = net_generic(seq_file_net(p), nfs_net_id);
return seq_list_next(v, &nn->nfs_volume_list, pos);
}
@@ -1363,7 +1341,7 @@ static void *nfs_volume_list_next(struct seq_file *p, void *v, loff_t *pos)
*/
static void nfs_volume_list_stop(struct seq_file *p, void *v)
{
- struct nfs_net *nn = net_generic(p->private, nfs_net_id);
+ struct nfs_net *nn = net_generic(seq_file_net(p), nfs_net_id);
spin_unlock(&nn->nfs_client_lock);
}
@@ -1376,7 +1354,7 @@ static int nfs_volume_list_show(struct seq_file *m, void *v)
struct nfs_server *server;
struct nfs_client *clp;
char dev[8], fsid[17];
- struct nfs_net *nn = net_generic(m->private, nfs_net_id);
+ struct nfs_net *nn = net_generic(seq_file_net(m), nfs_net_id);
/* display header on line 1 */
if (v == &nn->nfs_volume_list) {
@@ -1407,6 +1385,45 @@ static int nfs_volume_list_show(struct seq_file *m, void *v)
return 0;
}
+int nfs_fs_proc_net_init(struct net *net)
+{
+ struct nfs_net *nn = net_generic(net, nfs_net_id);
+ struct proc_dir_entry *p;
+
+ nn->proc_nfsfs = proc_net_mkdir(net, "nfsfs", net->proc_net);
+ if (!nn->proc_nfsfs)
+ goto error_0;
+
+ /* a file of servers with which we're dealing */
+ p = proc_create("servers", S_IFREG|S_IRUGO,
+ nn->proc_nfsfs, &nfs_server_list_fops);
+ if (!p)
+ goto error_1;
+
+ /* a file of volumes that we have mounted */
+ p = proc_create("volumes", S_IFREG|S_IRUGO,
+ nn->proc_nfsfs, &nfs_volume_list_fops);
+ if (!p)
+ goto error_2;
+ return 0;
+
+error_2:
+ remove_proc_entry("servers", nn->proc_nfsfs);
+error_1:
+ remove_proc_entry("fs/nfsfs", NULL);
+error_0:
+ return -ENOMEM;
+}
+
+void nfs_fs_proc_net_exit(struct net *net)
+{
+ struct nfs_net *nn = net_generic(net, nfs_net_id);
+
+ remove_proc_entry("volumes", nn->proc_nfsfs);
+ remove_proc_entry("servers", nn->proc_nfsfs);
+ remove_proc_entry("fs/nfsfs", NULL);
+}
+
/*
* initialise the /proc/fs/nfsfs/ directory
*/
@@ -1419,14 +1436,12 @@ int __init nfs_fs_proc_init(void)
goto error_0;
/* a file of servers with which we're dealing */
- p = proc_create("servers", S_IFREG|S_IRUGO,
- proc_fs_nfs, &nfs_server_list_fops);
+ p = proc_symlink("servers", proc_fs_nfs, "../../net/nfsfs/servers");
if (!p)
goto error_1;
/* a file of volumes that we have mounted */
- p = proc_create("volumes", S_IFREG|S_IRUGO,
- proc_fs_nfs, &nfs_volume_list_fops);
+ p = proc_symlink("volumes", proc_fs_nfs, "../../net/nfsfs/volumes");
if (!p)
goto error_2;
return 0;
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index abd37a380535..68921b01b792 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -1840,11 +1840,12 @@ EXPORT_SYMBOL_GPL(nfs_net_id);
static int nfs_net_init(struct net *net)
{
nfs_clients_init(net);
- return 0;
+ return nfs_fs_proc_net_init(net);
}
static void nfs_net_exit(struct net *net)
{
+ nfs_fs_proc_net_exit(net);
nfs_cleanup_cb_ident_idr(net);
}
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 617f36611d4a..e2a45ae5014e 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -195,7 +195,16 @@ extern struct rpc_clnt *nfs4_find_or_create_ds_client(struct nfs_client *,
#ifdef CONFIG_PROC_FS
extern int __init nfs_fs_proc_init(void);
extern void nfs_fs_proc_exit(void);
+extern int nfs_fs_proc_net_init(struct net *net);
+extern void nfs_fs_proc_net_exit(struct net *net);
#else
+static inline int nfs_fs_proc_net_init(struct net *net)
+{
+ return 0;
+}
+static inline void nfs_fs_proc_net_exit(struct net *net)
+{
+}
static inline int nfs_fs_proc_init(void)
{
return 0;
diff --git a/fs/nfs/netns.h b/fs/nfs/netns.h
index 8ee1fab83268..ef221fb8a183 100644
--- a/fs/nfs/netns.h
+++ b/fs/nfs/netns.h
@@ -29,6 +29,9 @@ struct nfs_net {
#endif
spinlock_t nfs_client_lock;
struct timespec boot_time;
+#ifdef CONFIG_PROC_FS
+ struct proc_dir_entry *proc_nfsfs;
+#endif
};
extern int nfs_net_id;