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authorLinus Torvalds <torvalds@linux-foundation.org>2018-06-04 07:58:06 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2018-06-04 07:58:06 -0700
commitf459c34538f57661e0fd1d3eaf7c0b17125ae011 (patch)
tree3addc82d7f792c4533501978798dad0095293933 /Documentation
parentLinux 4.17 (diff)
parentblk-mq: update nr_requests when switching to 'none' scheduler (diff)
downloadlinux-dev-f459c34538f57661e0fd1d3eaf7c0b17125ae011.tar.xz
linux-dev-f459c34538f57661e0fd1d3eaf7c0b17125ae011.zip
Merge tag 'for-4.18/block-20180603' of git://git.kernel.dk/linux-block
Pull block updates from Jens Axboe: - clean up how we pass around gfp_t and blk_mq_req_flags_t (Christoph) - prepare us to defer scheduler attach (Christoph) - clean up drivers handling of bounce buffers (Christoph) - fix timeout handling corner cases (Christoph/Bart/Keith) - bcache fixes (Coly) - prep work for bcachefs and some block layer optimizations (Kent). - convert users of bio_sets to using embedded structs (Kent). - fixes for the BFQ io scheduler (Paolo/Davide/Filippo) - lightnvm fixes and improvements (Matias, with contributions from Hans and Javier) - adding discard throttling to blk-wbt (me) - sbitmap blk-mq-tag handling (me/Omar/Ming). - remove the sparc jsflash block driver, acked by DaveM. - Kyber scheduler improvement from Jianchao, making it more friendly wrt merging. - conversion of symbolic proc permissions to octal, from Joe Perches. Previously the block parts were a mix of both. - nbd fixes (Josef and Kevin Vigor) - unify how we handle the various kinds of timestamps that the block core and utility code uses (Omar) - three NVMe pull requests from Keith and Christoph, bringing AEN to feature completeness, file backed namespaces, cq/sq lock split, and various fixes - various little fixes and improvements all over the map * tag 'for-4.18/block-20180603' of git://git.kernel.dk/linux-block: (196 commits) blk-mq: update nr_requests when switching to 'none' scheduler block: don't use blocking queue entered for recursive bio submits dm-crypt: fix warning in shutdown path lightnvm: pblk: take bitmap alloc. out of critical section lightnvm: pblk: kick writer on new flush points lightnvm: pblk: only try to recover lines with written smeta lightnvm: pblk: remove unnecessary bio_get/put lightnvm: pblk: add possibility to set write buffer size manually lightnvm: fix partial read error path lightnvm: proper error handling for pblk_bio_add_pages lightnvm: pblk: fix smeta write error path lightnvm: pblk: garbage collect lines with failed writes lightnvm: pblk: rework write error recovery path lightnvm: pblk: remove dead function lightnvm: pass flag on graceful teardown to targets lightnvm: pblk: check for chunk size before allocating it lightnvm: pblk: remove unnecessary argument lightnvm: pblk: remove unnecessary indirection lightnvm: pblk: return NVM_ error on failed submission lightnvm: pblk: warn in case of corrupted write buffer ...
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/block/null_blk.txt9
-rw-r--r--Documentation/scsi/scsi_eh.txt15
2 files changed, 8 insertions, 16 deletions
diff --git a/Documentation/block/null_blk.txt b/Documentation/block/null_blk.txt
index 733927a7b501..07f147381f32 100644
--- a/Documentation/block/null_blk.txt
+++ b/Documentation/block/null_blk.txt
@@ -71,13 +71,16 @@ use_per_node_hctx=[0/1]: Default: 0
1: The multi-queue block layer is instantiated with a hardware dispatch
queue for each CPU node in the system.
-use_lightnvm=[0/1]: Default: 0
- Register device with LightNVM. Requires blk-mq and CONFIG_NVM to be enabled.
-
no_sched=[0/1]: Default: 0
0: nullb* use default blk-mq io scheduler.
1: nullb* doesn't use io scheduler.
+blocking=[0/1]: Default: 0
+ 0: Register as a non-blocking blk-mq driver device.
+ 1: Register as a blocking blk-mq driver device, null_blk will set
+ the BLK_MQ_F_BLOCKING flag, indicating that it sometimes/always
+ needs to block in its ->queue_rq() function.
+
shared_tags=[0/1]: Default: 0
0: Tag set is not shared.
1: Tag set shared between devices for blk-mq. Only makes sense with
diff --git a/Documentation/scsi/scsi_eh.txt b/Documentation/scsi/scsi_eh.txt
index 11e447bdb3a5..1b7436932a2b 100644
--- a/Documentation/scsi/scsi_eh.txt
+++ b/Documentation/scsi/scsi_eh.txt
@@ -82,24 +82,13 @@ function
1. invokes optional hostt->eh_timed_out() callback. Return value can
be one of
- - BLK_EH_HANDLED
- This indicates that eh_timed_out() dealt with the timeout.
- The command is passed back to the block layer and completed
- via __blk_complete_requests().
-
- *NOTE* After returning BLK_EH_HANDLED the SCSI layer is
- assumed to be finished with the command, and no other
- functions from the SCSI layer will be called. So this
- should typically only be returned if the eh_timed_out()
- handler raced with normal completion.
-
- BLK_EH_RESET_TIMER
This indicates that more time is required to finish the
command. Timer is restarted. This action is counted as a
retry and only allowed scmd->allowed + 1(!) times. Once the
- limit is reached, action for BLK_EH_NOT_HANDLED is taken instead.
+ limit is reached, action for BLK_EH_DONE is taken instead.
- - BLK_EH_NOT_HANDLED
+ - BLK_EH_DONE
eh_timed_out() callback did not handle the command.
Step #2 is taken.