tree eabe7943ec5970936664dfd2b2e86e75c2c4b253
parent 5c0b4129c07b902b27d3f3ebc087757f534a3abd
author Boaz Harrosh <bharrosh@panasas.com> 1325835080 +0200
committer Trond Myklebust <Trond.Myklebust@netapp.com> 1325858133 -0500

pnfs-obj: Must return layout on IO error

As mandated by the standard. In case of an IO error, a pNFS
objects layout driver must return it's layout. This is because
all device errors are reported to the server as part of the
layout return buffer.

This is implemented the same way PNFS_LAYOUTRET_ON_SETATTR
is done, through a bit flag on the pnfs_layoutdriver_type->flags
member. The flag is set by the layout driver that wants a
layout_return preformed at pnfs_ld_{write,read}_done in case
of an error.
(Though I have not defined a wrapper like pnfs_ld_layoutret_on_setattr
 because this code is never called outside of pnfs.c and pnfs IO
 paths)

Without this patch 3.[0-2] Kernels leak memory and have an annoying
WARN_ON after every IO error utilizing the pnfs-obj driver.

[This patch is for 3.2 Kernel. 3.1/0 Kernels need a different patch]
CC: Stable Tree <stable@kernel.org>
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>