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nsfs: generalize ns_get_path() for path resolution with a task

ns_get_path() takes struct task_struct and proc_ns_ops as its parameters. For path resolution directly from a namespace, e.g. based on a networking device's net name space, we need more flexibility. Add a ns_get_path_cb() helper which will allow callers to use any method of obtaining the name space reference. Convert ns_get_path() to use ns_get_path_cb(). Following patches will bring a networking user.

Jakub Kicinski committed 8 years ago

Commit cdab6ba1 parent ad8ad792 files · +29 −3Browse files

Unified · Split

2 files
  1. fs/nsfs.c +26 −3
  2. include/linux/proc_ns.h +3 −0
fs/nsfs.c+26−3
@@ -103,14 +103,14 @@ slow: · 102 unmodified lines
103 goto got_it;103 goto got_it;
104}104}
105 105
106void *ns_get_path(struct path *path, struct task_struct *task,106void *ns_get_path_cb(struct path *path, ns_get_path_helper_t *ns_get_cb,
107 const struct proc_ns_operations *ns_ops)107 void *private_data)
108{108{
109 struct ns_common *ns;109 struct ns_common *ns;
110 void *ret;110 void *ret;
111 111
112again:112again:
113 ns = ns_ops->get(task);113 ns = ns_get_cb(private_data);
114 if (!ns)114 if (!ns)
115 return ERR_PTR(-ENOENT);115 return ERR_PTR(-ENOENT);
116 116
@@ -120,6 +120,29 @@ again: · 3 unmodified lines
120 return ret;120 return ret;
121}121}
122 122
123struct ns_get_path_task_args {
124 const struct proc_ns_operations *ns_ops;
125 struct task_struct *task;
126};
127
128static struct ns_common *ns_get_path_task(void *private_data)
129{
130 struct ns_get_path_task_args *args = private_data;
131
132 return args->ns_ops->get(args->task);
133}
134
135void *ns_get_path(struct path *path, struct task_struct *task,
136 const struct proc_ns_operations *ns_ops)
137{
138 struct ns_get_path_task_args args = {
139 .ns_ops = ns_ops,
140 .task = task,
141 };
142
143 return ns_get_path_cb(path, ns_get_path_task, &args);
144}
145
123int open_related_ns(struct ns_common *ns,146int open_related_ns(struct ns_common *ns,
124 struct ns_common *(*get_ns)(struct ns_common *ns))147 struct ns_common *(*get_ns)(struct ns_common *ns))
125{148{
include/linux/proc_ns.h+3−0
@@ -78,6 +78,9 @@ extern struct file *proc_ns_fget(int fd); · 77 unmodified lines
78#define get_proc_ns(inode) ((struct ns_common *)(inode)->i_private)78#define get_proc_ns(inode) ((struct ns_common *)(inode)->i_private)
79extern void *ns_get_path(struct path *path, struct task_struct *task,79extern void *ns_get_path(struct path *path, struct task_struct *task,
80 const struct proc_ns_operations *ns_ops);80 const struct proc_ns_operations *ns_ops);
81typedef struct ns_common *ns_get_path_helper_t(void *);
82extern void *ns_get_path_cb(struct path *path, ns_get_path_helper_t ns_get_cb,
83 void *private_data);
81 84
82extern int ns_get_name(char *buf, size_t size, struct task_struct *task,85extern int ns_get_name(char *buf, size_t size, struct task_struct *task,
83 const struct proc_ns_operations *ns_ops);86 const struct proc_ns_operations *ns_ops);