CVS commit: src/sys/dev/ata

["Jaromir Dolecek" <jdolecek%netbsd.org@localhost>]

Module Name:    src
Committed By:   jdolecek
Date:           Fri Aug 10 22:43:22 UTC 2018

Modified Files:
        src/sys/dev/ata: ata_subr.c atavar.h wd.c

Log Message:
fix race in wd_lastclose() on systems with two ide disks on same
channel, which happened when one disk had pending I/O while the other
disk executed the final disk flush - need to restart bufq processing
once xfer is freed in this case

it could happen e.g. on boot when system executes fsck on different
partitions on the two drives in parallell and hence open and closes
the disk devices repeatedly

add KASSERT() for empty bufq on wd_lastclose(), and fix similar issue
also on suspend/standby path

this was introduced by the NCQ merge and not dksubr - before the merge
each drive had their own xfer, so they could not block each other

fixes PR kern/52783 by Onno van der Linden; many thanks for extensive
help with tracking this down


To generate a diff of this commit:
cvs rdiff -u -r1.5 -r1.6 src/sys/dev/ata/ata_subr.c
cvs rdiff -u -r1.98 -r1.99 src/sys/dev/ata/atavar.h
cvs rdiff -u -r1.440 -r1.441 src/sys/dev/ata/wd.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.