tmpfs: allow decoding a file handle of an unlinked file

tmpfs uses the helper d_find_alias() to find a dentry from a decoded
inode, but d_find_alias() skips unhashed dentries, so unlinked files
cannot be decoded from a file handle.

This can be reproduced using xfstests test program open_by_handle:

  $ open_by handle -c /tmp/testdir
  $ open_by_handle -dk /tmp/testdir
  open_by_handle(/tmp/testdir/file000000) returned 116 incorrectly on an unlinked open file!

To fix this, if d_find_alias() can't find a hashed alias, call
d_find_any_alias() to return an unhashed one.

Link: http://lkml.kernel.org/r/CAOQ4uxg+qSLP0KwdW+h1tcPqOCQd+_pGZVXiePQB1TXCMBMctQ@mail.gmail.com
Signed-off-by: Amir Goldstein <[email protected]>
Reviewed-by: NeilBrown <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Jeff Layton <[email protected]>
Cc: "J. Bruce Fields" <[email protected]>
Cc: Al Viro <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions