1. 11 Nov, 2011 15 commits
  2. 09 Nov, 2011 19 commits
  3. 08 Nov, 2011 5 commits
  4. 07 Nov, 2011 1 commit
    • Al Viro's avatar
      VFS: we need to set LOOKUP_JUMPED on mountpoint crossing · a3fbbde7
      Al Viro authored
      Mountpoint crossing is similar to following procfs symlinks - we do
      not get ->d_revalidate() called for dentry we have arrived at, with
      unpleasant consequences for NFS4.
      
      Simple way to reproduce the problem in mainline:
      
          cat >/tmp/a.c <<'EOF'
          #include <unistd.h>
          #include <fcntl.h>
          #include <stdio.h>
          main()
          {
                  struct flock fl = {.l_type = F_RDLCK, .l_whence = SEEK_SET, .l_len = 1};
                  if (fcntl(0, F_SETLK, &fl))
                          perror("setlk");
          }
          EOF
          cc /tmp/a.c -o /tmp/test
      
      then on nfs4:
      
          mount --bind file1 file2
          /tmp/test < file1		# ok
          /tmp/test < file2		# spews "setlk: No locks available"...
      
      What happens is the missing call of ->d_revalidate() after mountpoint
      crossing and that's where NFS4 would issue OPEN request to server.
      
      The fix is simple - treat mountpoint crossing the same way we deal with
      following procfs-style symlinks.  I.e.  set LOOKUP_JUMPED...
      
      Cc: stable@kernel.org
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      a3fbbde7