tree 0a60fd245b1aff56a0b1470cadd6e242bfd4a2de
parent 70e9b3571107b88674cd55ae4bed33f76261e7d3
author Al Viro <viro@zeniv.linux.org.uk> 1299383905 -0500
committer Al Viro <viro@zeniv.linux.org.uk> 1300108526 -0400

switch non-create side of open() to use of do_last()

Instead of path_lookupat() doing trailing symlink resolution,
use the same scheme as on the O_CREAT side.  Walk with
LOOKUP_PARENT, then (in do_last()) look the final component
up, then either open it or return error or, if it's a symlink,
give the symlink back to path_openat() to be resolved there.

The really messy complication here is RCU.  We don't want to drop
out of RCU mode before the final lookup, since we don't want to
bounce parent directory ->d_count without a good reason.

Result is _not_ pretty; later in the series we'll clean it up.
For now we are roughly back where we'd been before the revert
done by Nick's series - top-level logics of path_openat() is
cleaned up, do_last() does actual opening, symlink resolution is
done uniformly.

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