btrfs: don't block if we can't acquire the reclaim lock

[linux-2.6-microblaze.git] / fs / file.c

diff --git a/fs/file.c b/fs/file.c
index f3a4bac..86dc995 100644 (file)
--- a/fs/file.c
+++ b/fs/file.c
@@ -629,17 +629,30 @@ int close_fd(unsigned fd)
 }
 EXPORT_SYMBOL(close_fd); /* for ksys_close() */
 
+/**
+ * last_fd - return last valid index into fd table
+ * @cur_fds: files struct
+ *
+ * Context: Either rcu read lock or files_lock must be held.
+ *
+ * Returns: Last valid index into fdtable.
+ */
+static inline unsigned last_fd(struct fdtable *fdt)
+{
+       return fdt->max_fds - 1;
+}
+
 static inline void __range_cloexec(struct files_struct *cur_fds,
                                   unsigned int fd, unsigned int max_fd)
 {
        struct fdtable *fdt;
 
-       if (fd > max_fd)
-               return;
-
+       /* make sure we're using the correct maximum value */
        spin_lock(&cur_fds->file_lock);
        fdt = files_fdtable(cur_fds);
-       bitmap_set(fdt->close_on_exec, fd, max_fd - fd + 1);
+       max_fd = min(last_fd(fdt), max_fd);
+       if (fd <= max_fd)
+               bitmap_set(fdt->close_on_exec, fd, max_fd - fd + 1);
        spin_unlock(&cur_fds->file_lock);
 }
 
@@ -1068,8 +1081,6 @@ out_unlock:
 
 /**
  * __receive_fd() - Install received file into file descriptor table
- *
- * @fd: fd to install into (if negative, a new fd will be allocated)
  * @file: struct file that was received from another process
  * @ufd: __user pointer to write new fd number to
  * @o_flags: the O_* flags to apply to the new fd entry
@@ -1083,7 +1094,7 @@ out_unlock:
  *
  * Returns newly install fd or -ve on error.
  */
-int __receive_fd(int fd, struct file *file, int __user *ufd, unsigned int o_flags)
+int __receive_fd(struct file *file, int __user *ufd, unsigned int o_flags)
 {
        int new_fd;
        int error;
@@ -1092,32 +1103,33 @@ int __receive_fd(int fd, struct file *file, int __user *ufd, unsigned int o_flag
        if (error)
                return error;
 
-       if (fd < 0) {
-               new_fd = get_unused_fd_flags(o_flags);
-               if (new_fd < 0)
-                       return new_fd;
-       } else {
-               new_fd = fd;
-       }
+       new_fd = get_unused_fd_flags(o_flags);
+       if (new_fd < 0)
+               return new_fd;
 
        if (ufd) {
                error = put_user(new_fd, ufd);
                if (error) {
-                       if (fd < 0)
-                               put_unused_fd(new_fd);
+                       put_unused_fd(new_fd);
                        return error;
                }
        }
 
-       if (fd < 0) {
-               fd_install(new_fd, get_file(file));
-       } else {
-               error = replace_fd(new_fd, file, o_flags);
-               if (error)
-                       return error;
-       }
+       fd_install(new_fd, get_file(file));
+       __receive_sock(file);
+       return new_fd;
+}
 
-       /* Bump the sock usage counts, if any. */
+int receive_fd_replace(int new_fd, struct file *file, unsigned int o_flags)
+{
+       int error;
+
+       error = security_file_receive(file);
+       if (error)
+               return error;
+       error = replace_fd(new_fd, file, o_flags);
+       if (error)
+               return error;
        __receive_sock(file);
        return new_fd;
 }