diff options
| -rw-r--r-- | fs/namespace.c | 14 | ||||
| -rw-r--r-- | fs/proc/base.c | 108 | ||||
| -rw-r--r-- | include/linux/mnt_namespace.h | 11 |
3 files changed, 70 insertions, 63 deletions
diff --git a/fs/namespace.c b/fs/namespace.c index cefa1d9939b0..dfdf51e81c1c 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -724,20 +724,21 @@ void save_mount_options(struct super_block *sb, char *options) } EXPORT_SYMBOL(save_mount_options); +#ifdef CONFIG_PROC_FS /* iterator */ static void *m_start(struct seq_file *m, loff_t *pos) { - struct mnt_namespace *n = m->private; + struct proc_mounts *p = m->private; down_read(&namespace_sem); - return seq_list_start(&n->list, *pos); + return seq_list_start(&p->ns->list, *pos); } static void *m_next(struct seq_file *m, void *v, loff_t *pos) { - struct mnt_namespace *n = m->private; + struct proc_mounts *p = m->private; - return seq_list_next(v, &n->list, pos); + return seq_list_next(v, &p->ns->list, pos); } static void m_stop(struct seq_file *m, void *v) @@ -794,7 +795,7 @@ static int show_vfsmnt(struct seq_file *m, void *v) return err; } -struct seq_operations mounts_op = { +const struct seq_operations mounts_op = { .start = m_start, .next = m_next, .stop = m_stop, @@ -833,12 +834,13 @@ static int show_vfsstat(struct seq_file *m, void *v) return err; } -struct seq_operations mountstats_op = { +const struct seq_operations mountstats_op = { .start = m_start, .next = m_next, .stop = m_stop, .show = show_vfsstat, }; +#endif /* CONFIG_PROC_FS */ /** * may_umount_tree - check if a mount tree is busy diff --git a/fs/proc/base.c b/fs/proc/base.c index 7313c62e3e9d..a04b3db7a296 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -502,17 +502,14 @@ static const struct inode_operations proc_def_inode_operations = { .setattr = proc_setattr, }; -extern const struct seq_operations mounts_op; -struct proc_mounts { - struct seq_file m; - int event; -}; - -static int mounts_open(struct inode *inode, struct file *file) +static int mounts_open_common(struct inode *inode, struct file *file, + const struct seq_operations *op) { struct task_struct *task = get_proc_task(inode); struct nsproxy *nsp; struct mnt_namespace *ns = NULL; + struct fs_struct *fs = NULL; + struct path root; struct proc_mounts *p; int ret = -EINVAL; @@ -525,40 +522,61 @@ static int mounts_open(struct inode *inode, struct file *file) get_mnt_ns(ns); } rcu_read_unlock(); - + if (ns) + fs = get_fs_struct(task); put_task_struct(task); } - if (ns) { - ret = -ENOMEM; - p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL); - if (p) { - file->private_data = &p->m; - ret = seq_open(file, &mounts_op); - if (!ret) { - p->m.private = ns; - p->event = ns->event; - return 0; - } - kfree(p); - } - put_mnt_ns(ns); - } + if (!ns) + goto err; + if (!fs) + goto err_put_ns; + + read_lock(&fs->lock); + root = fs->root; + path_get(&root); + read_unlock(&fs->lock); + put_fs_struct(fs); + + ret = -ENOMEM; + p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL); + if (!p) + goto err_put_path; + + file->private_data = &p->m; + ret = seq_open(file, op); + if (ret) + goto err_free; + + p->m.private = p; + p->ns = ns; + p->root = root; + p->event = ns->event; + + return 0; + + err_free: + kfree(p); + err_put_path: + path_put(&root); + err_put_ns: + put_mnt_ns(ns); + err: return ret; } static int mounts_release(struct inode *inode, struct file *file) { - struct seq_file *m = file->private_data; - struct mnt_namespace *ns = m->private; - put_mnt_ns(ns); + struct proc_mounts *p = file->private_data; + path_put(&p->root); + put_mnt_ns(p->ns); return seq_release(inode, file); } static unsigned mounts_poll(struct file *file, poll_table *wait) { struct proc_mounts *p = file->private_data; - struct mnt_namespace *ns = p->m.private; + struct mnt_namespace *ns = p->ns; unsigned res = 0; poll_wait(file, &ns->poll, wait); @@ -573,6 +591,11 @@ static unsigned mounts_poll(struct file *file, poll_table *wait) return res; } +static int mounts_open(struct inode *inode, struct file *file) +{ + return mounts_open_common(inode, file, &mounts_op); +} + static const struct file_operations proc_mounts_operations = { .open = mounts_open, .read = seq_read, @@ -581,38 +604,9 @@ static const struct file_operations proc_mounts_operations = { .poll = mounts_poll, }; -extern const struct seq_operations mountstats_op; static int mountstats_open(struct inode *inode, struct file *file) { - int ret = seq_open(file, &mountstats_op); - - if (!ret) { - struct seq_file *m = file->private_data; - struct nsproxy *nsp; - struct mnt_namespace *mnt_ns = NULL; - struct task_struct *task = get_proc_task(inode); - - if (task) { - rcu_read_lock(); - nsp = task_nsproxy(task); - if (nsp) { - mnt_ns = nsp->mnt_ns; - if (mnt_ns) - get_mnt_ns(mnt_ns); - } - rcu_read_unlock(); - - put_task_struct(task); - } - - if (mnt_ns) - m->private = mnt_ns; - else { - seq_release(inode, file); - ret = -EINVAL; - } - } - return ret; + return mounts_open_common(inode, file, &mountstats_op); } static const struct file_operations proc_mountstats_operations = { diff --git a/include/linux/mnt_namespace.h b/include/linux/mnt_namespace.h index 8eed44f8ca73..c078aacc8116 100644 --- a/include/linux/mnt_namespace.h +++ b/include/linux/mnt_namespace.h @@ -5,6 +5,7 @@ #include <linux/mount.h> #include <linux/sched.h> #include <linux/nsproxy.h> +#include <linux/seq_file.h> struct mnt_namespace { atomic_t count; @@ -14,6 +15,13 @@ struct mnt_namespace { int event; }; +struct proc_mounts { + struct seq_file m; /* must be the first element */ + struct mnt_namespace *ns; + struct path root; + int event; +}; + extern struct mnt_namespace *copy_mnt_ns(unsigned long, struct mnt_namespace *, struct fs_struct *); extern void __put_mnt_ns(struct mnt_namespace *ns); @@ -37,5 +45,8 @@ static inline void get_mnt_ns(struct mnt_namespace *ns) atomic_inc(&ns->count); } +extern const struct seq_operations mounts_op; +extern const struct seq_operations mountstats_op; + #endif #endif |