take rlimit check to callers of expand_files()

... except for one in android, where the check is different
and already done in caller.  No need to recalculate rlimit
many times in alloc_fd() either.

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

2 files changed, 12 insertions, 7 deletions

diff --git a/fs/fcntl.c b/fs/fcntl.c
index 887b5ba8c9b5..08e6af5c1b1f 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -64,6 +64,9 @@ SYSCALL_DEFINE3(dup3, unsigned int, oldfd, unsigned int, newfd, int, flags)
         if (unlikely(oldfd == newfd))
                 return -EINVAL;
 
+        if (newfd >= rlimit(RLIMIT_NOFILE))
+                return -EMFILE;
+
         spin_lock(&files->file_lock);
         err = expand_files(files, newfd);
         file = fcheck(oldfd);
diff --git a/fs/file.c b/fs/file.c
index 5b46e9970a7a..08922af4a62c 100644
--- a/fs/file.c
+++ b/fs/file.c
@@ -251,13 +251,6 @@ int expand_files(struct files_struct *files, int nr)
 
         fdt = files_fdtable(files);
 
-        /*
-         * N.B. For clone tasks sharing a files structure, this test
-         * will limit the total number of files that can be opened.
-         */
-        if (nr >= rlimit(RLIMIT_NOFILE))
-                return -EMFILE;
-
         /* Do we need to expand? */
         if (nr < fdt->max_fds)
                 return 0;
@@ -431,6 +424,7 @@ int alloc_fd(unsigned start, unsigned flags)
 {
         struct files_struct *files = current->files;
         unsigned int fd;
+        unsigned end = rlimit(RLIMIT_NOFILE);
         int error;
         struct fdtable *fdt;
 
@@ -444,6 +438,14 @@ repeat:
         if (fd < fdt->max_fds)
                 fd = find_next_zero_bit(fdt->open_fds, fdt->max_fds, fd);
 
+        /*
+         * N.B. For clone tasks sharing a files structure, this test
+         * will limit the total number of files that can be opened.
+         */
+        error = -EMFILE;
+        if (fd >= end)
+                goto out;
+
         error = expand_files(files, fd);
         if (error < 0)
                 goto out;