[PATCH v2 0/4] fix / cleanup async scsi scanning

From: Dan Williams
Date: Wed May 30 2012 - 14:05:03 EST


Commit a7a20d10 "[SCSI] sd: limit the scope of the async probe domain"
introduces a boot regression by moving sd probe work off of the global
async queue. Using a local async domain hides the probe work from being
synchronized by wait_for_device_probe()->async_synchronize_full().

Fix this by teaching async_synchronize_full() to flush all async work
regardless of domain, and take the opportunity to convert scsi scanning
to async_schedule(). This enables wait_for_device_probe() to flush scsi
scanning work.

Changes since v1: http://marc.info/?l=linux-scsi&m=133793153025832&w=2

1/ Tested to fix the boot hang that Meelis reported with v1. Reworked
async_synchronize_full() to walk through all the active domains,
otherwise we spin on !list_empty(async_domains) and prevent the async
context from running.

2/ Added the ability for domains to opt-out of global syncing as
requested by Arjan, but also needed for domains that don't want to worry
about list corruption when the domain goes out of scope (stack-allocated
domains).

---

Dan Williams (4):
async: introduce 'async_domain' type
async: make async_synchronize_full() flush all work regardless of domain
scsi: queue async scan work to an async_schedule domain
scsi: cleanup usages of scsi_complete_async_scans


drivers/regulator/core.c | 2 +
drivers/scsi/libsas/sas_ata.c | 2 +
drivers/scsi/scsi.c | 4 ++
drivers/scsi/scsi_priv.h | 3 +-
drivers/scsi/scsi_scan.c | 24 +++----------
drivers/scsi/scsi_wait_scan.c | 15 +++-----
include/linux/async.h | 36 +++++++++++++++++--
include/scsi/scsi_scan.h | 11 ------
kernel/async.c | 76 +++++++++++++++++++++++++++++++----------
kernel/power/hibernate.c | 8 ----
kernel/power/user.c | 2 -
11 files changed, 107 insertions(+), 76 deletions(-)
delete mode 100644 include/scsi/scsi_scan.h
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