teach proc_self_get_link()/proc_thread_self_get_link() to work in RCU mode

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

2 files changed, 7 insertions, 10 deletions

diff --git a/fs/proc/self.c b/fs/proc/self.c
index 9dd0ae6aefdb..7a8b19ead3b6 100644
--- a/fs/proc/self.c
+++ b/fs/proc/self.c
@@ -25,14 +25,12 @@ static const char *proc_self_get_link(struct dentry *dentry,
         pid_t tgid = task_tgid_nr_ns(current, ns);
         char *name;
 
-        if (!dentry)
-                return ERR_PTR(-ECHILD);
         if (!tgid)
                 return ERR_PTR(-ENOENT);
         /* 11 for max length of signed int in decimal + NULL term */
-        name = kmalloc(12, GFP_KERNEL);
-        if (!name)
-                return ERR_PTR(-ENOMEM);
+        name = kmalloc(12, dentry ? GFP_KERNEL : GFP_ATOMIC);
+        if (unlikely(!name))
+                return dentry ? ERR_PTR(-ENOMEM) : ERR_PTR(-ECHILD);
         sprintf(name, "%d", tgid);
         return *cookie = name;
 }
diff --git a/fs/proc/thread_self.c b/fs/proc/thread_self.c
index 50eef6f3e671..03eaa84604da 100644
--- a/fs/proc/thread_self.c
+++ b/fs/proc/thread_self.c
@@ -27,13 +27,12 @@ static const char *proc_thread_self_get_link(struct dentry *dentry,
         pid_t pid = task_pid_nr_ns(current, ns);
         char *name;
 
-        if (!dentry)
-                return ERR_PTR(-ECHILD);
         if (!pid)
                 return ERR_PTR(-ENOENT);
-        name = kmalloc(PROC_NUMBUF + 6 + PROC_NUMBUF, GFP_KERNEL);
-        if (!name)
-                return ERR_PTR(-ENOMEM);
+        name = kmalloc(PROC_NUMBUF + 6 + PROC_NUMBUF,
+                                dentry ? GFP_KERNEL : GFP_ATOMIC);
+        if (unlikely(!name))
+                return dentry ? ERR_PTR(-ENOMEM) : ERR_PTR(-ECHILD);
         sprintf(name, "%d/task/%d", tgid, pid);
         return *cookie = name;
 }