Justin T. Gibbs f03f7a0ca3 Correct bioq_disksort so that bioq_insert_tail() offers barrier semantic. ... Add the BIO_ORDERED flag for struct bio and update bio clients to use it. The barrier semantics of bioq_insert_tail() were broken in two ways: o In bioq_disksort(), an added bio could be inserted at the head of the queue, even when a barrier was present, if the sort key for the new entry was less than that of the last queued barrier bio. o The last_offset used to generate the sort key for newly queued bios did not stay at the position of the barrier until either the barrier was de-queued, or a new barrier (which updates last_offset) was queued. When a barrier is in effect, we know that the disk will pass through the barrier position just before the "blocked bios" are released, so using the barrier's offset for last_offset is the optimal choice. sys/geom/sched/subr_disk.c: sys/kern/subr_disk.c: o Update last_offset in bioq_insert_tail(). o Only update last_offset in bioq_remove() if the removed bio is at the head of the queue (typically due to a call via bioq_takefirst()) and no barrier is active. o In bioq_disksort(), if we have a barrier (insert_point is non-NULL), set prev to the barrier and cur to it's next element. Now that last_offset is kept at the barrier position, this change isn't strictly necessary, but since we have to take a decision branch anyway, it does avoid one, no-op, loop iteration in the while loop that immediately follows. o In bioq_disksort(), bypass the normal sort for bios with the BIO_ORDERED attribute and instead insert them into the queue with bioq_insert_tail(). bioq_insert_tail() not only gives the desired command order during insertion, but also provides barrier semantics so that commands disksorted in the future cannot pass the just enqueued transaction. sys/sys/bio.h: Add BIO_ORDERED as bit 4 of the bio_flags field in struct bio. sys/cam/ata/ata_da.c: sys/cam/scsi/scsi_da.c Use an ordered command for SCSI/ATA-NCQ commands issued in response to bios with the BIO_ORDERED flag set. sys/cam/scsi/scsi_da.c Use an ordered tag when issuing a synchronize cache command. Wrap some lines to 80 columns. sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev_geom.c sys/geom/geom_io.c Mark bios with the BIO_FLUSH command as BIO_ORDERED. Sponsored by: Spectra Logic Corporation MFC after: 1 month		2010-09-02 19:40:28 +00:00
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scsi_all.c	Make additional definitions up to and including SPC-4. Add in definitions	2010-06-08 05:14:18 +00:00
scsi_all.h	For the target port groups structures, don't allocate the initial element.	2010-06-14 22:02:18 +00:00
scsi_cd.c	Export PCI IDs of ATA/SATA controllers through CAM and ata(4) layers to	2010-07-25 15:43:52 +00:00
scsi_cd.h
scsi_ch.c	MFp4: Large set of CAM inprovements.	2010-01-28 08:41:30 +00:00
scsi_ch.h	Make additional definitions up to and including SPC-4. Add in definitions	2010-06-08 05:14:18 +00:00
scsi_da.c	Correct bioq_disksort so that bioq_insert_tail() offers barrier semantic.	2010-09-02 19:40:28 +00:00
scsi_da.h
scsi_dvcfg.h
scsi_iu.h
scsi_low.c	MFp4: Large set of CAM inprovements.	2010-01-28 08:41:30 +00:00
scsi_low.h	Add a new 'why' argument to kdb_enter(), and a set of constants to use	2007-12-25 17:52:02 +00:00
scsi_low_pisa.c
scsi_low_pisa.h
scsi_message.h
scsi_pass.c	MFp4: Large set of CAM inprovements.	2010-01-28 08:41:30 +00:00
scsi_pass.h
scsi_pt.c	Replace most of priority numbers with defines. No logical changes.	2009-10-23 08:27:55 +00:00
scsi_pt.h
scsi_sa.c	Replace most of priority numbers with defines. No logical changes.	2009-10-23 08:27:55 +00:00
scsi_sa.h
scsi_ses.c	Remove extraneous semicolons, no functional changes.	2010-01-07 21:01:37 +00:00
scsi_ses.h	Fix ioctl to not get swallowed by ioctl code (i.e., make sure the darned	2006-01-18 08:37:27 +00:00
scsi_sg.c	Pick up the right change, not it's close cousin. The one	2010-05-11 22:51:13 +00:00
scsi_sg.h	A fix for the SG_GET_TIMEOUT function slipped into a previous commit by	2007-04-10 20:03:42 +00:00
scsi_targ_bh.c	Remove extraneous semicolons, no functional changes.	2010-01-07 21:01:37 +00:00
scsi_target.c	Fix two (very common) occurrences of s/sytem/system in comments.	2010-08-02 18:06:49 +00:00
scsi_targetio.h
scsi_xpt.c	Implement the usage of Report Luns as part of SCSI probing for SCP3 or	2010-06-08 16:17:25 +00:00