Gitweb:     
http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=22d2b35b200f76085c16a2e14ca30b58510fcbe7
Commit:     22d2b35b200f76085c16a2e14ca30b58510fcbe7
Parent:     18796aa00243a594a2bd6733f1360aa38c3cd8f4
Author:     Ulrich Drepper <[EMAIL PROTECTED]>
AuthorDate: Tue Oct 16 23:30:26 2007 -0700
Committer:  Linus Torvalds <[EMAIL PROTECTED]>
CommitDate: Wed Oct 17 08:43:01 2007 -0700

    F_DUPFD_CLOEXEC implementation
    
    One more small change to extend the availability of creation of file
    descriptors with FD_CLOEXEC set.  Adding a new command to fcntl() requires
    no new system call and the overall impact on code size if minimal.
    
    If this patch gets accepted we will also add this change to the next
    revision of the POSIX spec.
    
    To test the patch, use the following little program.  Adjust the value of
    F_DUPFD_CLOEXEC appropriately.
    
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    #include <errno.h>
    #include <fcntl.h>
    #include <stdio.h>
    #include <stdlib.h>
    #include <unistd.h>
    
    #ifndef F_DUPFD_CLOEXEC
    # define F_DUPFD_CLOEXEC 12
    #endif
    
    int
    main (int argc, char *argv[])
    {
      if  (argc > 1)
        {
          if (fcntl (3, F_GETFD) == 0)
        {
          puts ("descriptor not closed");
          exit (1);
        }
          if (errno != EBADF)
        {
          puts ("error not EBADF");
          exit (1);
        }
    
          exit (0);
        }
      int fd = fcntl (STDOUT_FILENO, F_DUPFD_CLOEXEC, 0);
      if (fd == -1 && errno == EINVAL)
        {
          puts ("F_DUPFD_CLOEXEC not supported");
          return 0;
        }
      if (fd != 3)
        {
          puts ("program called with descriptors other than 0,1,2");
          return 1;
        }
    
      execl ("/proc/self/exe", "/proc/self/exe", "1", NULL);
      puts ("execl failed");
      return 1;
    }
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    
    Signed-off-by: Ulrich Drepper <[EMAIL PROTECTED]>
    Cc: Al Viro <[EMAIL PROTECTED]>
    Cc: Christoph Hellwig <[EMAIL PROTECTED]>
    Cc: <[EMAIL PROTECTED]>
    Cc: Kyle McMartin <[EMAIL PROTECTED]>
    Cc: Stephen Rothwell <[EMAIL PROTECTED]>
    Signed-off-by: Andrew Morton <[EMAIL PROTECTED]>
    Signed-off-by: Linus Torvalds <[EMAIL PROTECTED]>
---
 fs/fcntl.c            |   12 ++++++++----
 include/linux/fcntl.h |   15 ++++++++++-----
 2 files changed, 18 insertions(+), 9 deletions(-)

diff --git a/fs/fcntl.c b/fs/fcntl.c
index 78b2ff0..c9db73f 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -110,7 +110,7 @@ out:
        return error;
 }
 
-static int dupfd(struct file *file, unsigned int start)
+static int dupfd(struct file *file, unsigned int start, int cloexec)
 {
        struct files_struct * files = current->files;
        struct fdtable *fdt;
@@ -122,7 +122,10 @@ static int dupfd(struct file *file, unsigned int start)
                /* locate_fd() may have expanded fdtable, load the ptr */
                fdt = files_fdtable(files);
                FD_SET(fd, fdt->open_fds);
-               FD_CLR(fd, fdt->close_on_exec);
+               if (cloexec)
+                       FD_SET(fd, fdt->close_on_exec);
+               else
+                       FD_CLR(fd, fdt->close_on_exec);
                spin_unlock(&files->file_lock);
                fd_install(fd, file);
        } else {
@@ -195,7 +198,7 @@ asmlinkage long sys_dup(unsigned int fildes)
        struct file * file = fget(fildes);
 
        if (file)
-               ret = dupfd(file, 0);
+               ret = dupfd(file, 0, 0);
        return ret;
 }
 
@@ -319,8 +322,9 @@ static long do_fcntl(int fd, unsigned int cmd, unsigned 
long arg,
 
        switch (cmd) {
        case F_DUPFD:
+       case F_DUPFD_CLOEXEC:
                get_file(filp);
-               err = dupfd(filp, arg);
+               err = dupfd(filp, arg, cmd == F_DUPFD_CLOEXEC);
                break;
        case F_GETFD:
                err = get_close_on_exec(fd) ? FD_CLOEXEC : 0;
diff --git a/include/linux/fcntl.h b/include/linux/fcntl.h
index 40b9326..8603740 100644
--- a/include/linux/fcntl.h
+++ b/include/linux/fcntl.h
@@ -3,12 +3,17 @@
 
 #include <asm/fcntl.h>
 
-/* Cancel a blocking posix lock; internal use only until we expose an
- * asynchronous lock api to userspace: */
-#define F_CANCELLK     (F_LINUX_SPECIFIC_BASE+5)
+#define F_SETLEASE     (F_LINUX_SPECIFIC_BASE + 0)
+#define F_GETLEASE     (F_LINUX_SPECIFIC_BASE + 1)
 
-#define F_SETLEASE     (F_LINUX_SPECIFIC_BASE+0)
-#define F_GETLEASE     (F_LINUX_SPECIFIC_BASE+1)
+/*
+ * Cancel a blocking posix lock; internal use only until we expose an
+ * asynchronous lock api to userspace:
+ */
+#define F_CANCELLK     (F_LINUX_SPECIFIC_BASE + 5)
+
+/* Create a file descriptor with FD_CLOEXEC set. */
+#define F_DUPFD_CLOEXEC        (F_LINUX_SPECIFIC_BASE + 6)
 
 /*
  * Request nofications on a directory.
-
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