ide-disk: Fix request requeuing

Simon Kirby reported that on his RAID setup with idedisk underneath
the box OOMs after a couple of days of runtime. Running with
CONFIG_DEBUG_KMEMLEAK pointed to idedisk_prep_fn() which unconditionally
allocates an ide_cmd struct. However, ide_requeue_and_plug() can be
called more than once per request, either from the request issue or the
IRQ handler path and do blk_peek_request() ends up in idedisk_prep_fn()
repeatedly, allocating a struct ide_cmd everytime and "forgetting" the
previous pointer.

Make sure the code reuses the old allocated chunk.

Reported-and-tested-by: Simon Kirby <[email protected]>
Cc: <[email protected]> [ 39.x, 3.0.x ]
Link: http://marc.info/?l=linux-kernel&m=131667641517919
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Borislav Petkov <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

0 files changed, 0 insertions, 0 deletions