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2009-02-09tracing/blktrace: move the tracing file to kernel/traceFrederic Weisbecker
Impact: cleanup Move blktrace.c to kernel/trace, also move its config entry. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com> Acked-by: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-06trace: Call tracing_reset_online_cpus before tracer->init()Arnaldo Carvalho de Melo
Impact: cleanup To make it easy for ftrace plugin writers, as this was open coded in the existing plugins Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Acked-by: Frédéric Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-06tracing: Introduce trace_buffer_{lock_reserve,unlock_commit}Arnaldo Carvalho de Melo
Impact: new API These new functions do what previously was being open coded, reducing the number of details ftrace plugin writers have to worry about. It also standardizes the handling of stacktrace, userstacktrace and other trace options we may introduce in the future. With this patch, for instance, the blk tracer (and some others already in the tree) can use the "userstacktrace" /d/tracing/trace_options facility. $ codiff /tmp/vmlinux.before /tmp/vmlinux.after linux-2.6-tip/kernel/trace/trace.c: trace_vprintk | -5 trace_graph_return | -22 trace_graph_entry | -26 trace_function | -45 __ftrace_trace_stack | -27 ftrace_trace_userstack | -29 tracing_sched_switch_trace | -66 tracing_stop | +1 trace_seq_to_user | -1 ftrace_trace_special | -63 ftrace_special | +1 tracing_sched_wakeup_trace | -70 tracing_reset_online_cpus | -1 13 functions changed, 2 bytes added, 355 bytes removed, diff: -353 linux-2.6-tip/block/blktrace.c: __blk_add_trace | -58 1 function changed, 58 bytes removed, diff: -58 linux-2.6-tip/kernel/trace/trace.c: trace_buffer_lock_reserve | +88 trace_buffer_unlock_commit | +86 2 functions changed, 174 bytes added, diff: +174 /tmp/vmlinux.after: 16 functions changed, 176 bytes added, 413 bytes removed, diff: -237 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Acked-by: Frédéric Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-06ring_buffer: remove unused flags parameterArnaldo Carvalho de Melo
Impact: API change, cleanup >From ring_buffer_{lock_reserve,unlock_commit}. $ codiff /tmp/vmlinux.before /tmp/vmlinux.after linux-2.6-tip/kernel/trace/trace.c: trace_vprintk | -14 trace_graph_return | -14 trace_graph_entry | -10 trace_function | -8 __ftrace_trace_stack | -8 ftrace_trace_userstack | -8 tracing_sched_switch_trace | -8 ftrace_trace_special | -12 tracing_sched_wakeup_trace | -8 9 functions changed, 90 bytes removed, diff: -90 linux-2.6-tip/block/blktrace.c: __blk_add_trace | -1 1 function changed, 1 bytes removed, diff: -1 /tmp/vmlinux.after: 10 functions changed, 91 bytes removed, diff: -91 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Acked-by: Frédéric Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-05trace: Remove unused trace_array_cpu parameterArnaldo Carvalho de Melo
Impact: cleanup Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-05trace: assign defaults at register_ftrace_eventArnaldo Carvalho de Melo
Impact: simplification of tracers As all tracers are doing this we might as well do it in register_ftrace_event and save one branch each time we call these callbacks. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-04trace: make the trace_event callbacks return enum print_line_tArnaldo Carvalho de Melo
As they actually all return these enumerators. Reported-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-04trace: judicious error checking of trace_seq resultsArnaldo Carvalho de Melo
Impact: bugfix and cleanup Some callsites were returning either TRACE_ITER_PARTIAL_LINE if the trace_seq routines (trace_seq_printf, etc) returned 0 meaning its buffer was full, or zero otherwise. But... /* Return values for print_line callback */ enum print_line_t { TRACE_TYPE_PARTIAL_LINE = 0, /* Retry after flushing the seq */ TRACE_TYPE_HANDLED = 1, TRACE_TYPE_UNHANDLED = 2 /* Relay to other output functions */ }; In other cases the return value was not being relayed at all. Most of the time it didn't hurt because the page wasn't get filled, but for correctness sake, handle the return values everywhere. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-03blktrace: fix coding style in recent patchesArnaldo Carvalho de Melo
Impact: cleanup Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-03blkftrace: binary tracing, synthesizing old formatArnaldo Carvalho de Melo
Impact: new feature With this and a blkrawverify modified not to verify the sequence numbers we can start using the userspace tools to verify that the data produced with the ftrace plugin works as expected. Example: [root@f10-1 ~]# echo 1 > /sys/block/sda/sda1/trace/enable [root@f10-1 ~]# echo bin > /d/tracing/trace_options [root@f10-1 ~]# echo blk > /d/tracing/current_tracer [root@f10-1 ~]# cat /d/tracing/trace_pipe > sda1.blktrace.0 ^C [root@f10-1 ~]# ./blkrawverify --noseq sda1 Verifying sda1 CPU 0 Wrote output to sda1.verify.out [root@f10-1 ~]# cat sda1.verify.out --------------- Verifying sda1 --------------------- Summary for cpu 0: 1349 valid + 0 invalid (100.0%) processed [root@f10-1 ~]# Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-03trace: Change struct trace_event callbacks parameter listArnaldo Carvalho de Melo
Impact: API change The trace_seq and trace_entry are in trace_iterator, where there are more fields that may be needed by tracers, so just pass the tracer_iterator as is already the case for struct tracer->print_line. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-03Merge branches 'tracing/ftrace', 'tracing/kmemtrace' and 'linus' into ↵Ingo Molnar
tracing/core
2009-02-02block: fix oops in blk_queue_io_stat()Jens Axboe
Some initial probe requests don't have disk->queue mapped yet, so we can't rely on a non-NULL queue in blk_queue_io_stat(). Wrap it in blk_do_io_stat(). Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-01-30cfq-iosched: Allow RT requests to pre-empt ongoing BE timesliceDivyesh Shah
This patch adds the ability to pre-empt an ongoing BE timeslice when a RT request is waiting for the current timeslice to complete. This reduces the wait time to disk for RT requests from an upper bound of 4 (current value of cfq_quantum) to 1 disk request. Applied Jens' suggeested changes to avoid the rb lookup and use !cfq_class_rt() and retested. Latency(secs) for the RT task when doing sequential reads from 10G file. | only RT | RT + BE | RT + BE + this patch small (512 byte) reads | 143 | 163 | 145 large (1Mb) reads | 142 | 158 | 146 Signed-off-by: Divyesh Shah <dpshah@google.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-01-30block: add sysfs file for controlling io stats accountingJens Axboe
This allows us to turn off disk stat accounting completely, for the cases where the 0.5-1% reduction in system time is important. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-01-30block: silently error an unsupported barrier bioJens Axboe
This fixes a "regression" from 2.6.28, where the barrier probes that file systems may do would trigger additional end request warnings in dmesg. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-01-30block: Fix documentation for blkdev_issue_flush()Theodore Ts'o
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-01-30block: seperate bio/request unplug and sync bitsJens Axboe
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-01-30block: export SSD/non-rotational queue flag through sysfsBartlomiej Zolnierkiewicz
For some devices (i.e. CFA ATA) we can't reliably detect whether the device is of rotational or non-rotational type so we need to leave the final decision about this setting to the user-space. As a bonus do a minor CodingStyle fixup in queue_nomerges_store(). Suggested-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-01-30block: get rid of the manual directory counting in blktraceJens Axboe
It can result in a stuck blktrace system, if --kill is used. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-01-30block: Allow empty integrity profileMartin K. Petersen
Allow a block device to allocate and register an integrity profile without providing a template. This allows DM to preallocate a profile to avoid deadlocks during table reconfiguration. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-01-29blktrace: Use tracing_reset_online_cpusArnaldo Carvalho de Melo
Impact: cleanup Use tracing_reset_online_cpus instead of open coding it. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-27blktrace: the ftrace interface needs CONFIG_TRACINGArnaldo Carvalho de Melo
Impact: build fix Also mention in the help text that blktrace now can be used using the ftrace interface. Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-26tracing/blktrace: fix up checkpatch reported problems in ftrace plugin patchArnaldo Carvalho de Melo
Also make sure sparse (make C=2 block/blktrace.o) is happy too. Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-26blktrace: add ftrace pluginArnaldo Carvalho de Melo
Impact: New way of using the blktrace infrastructure This drops the requirement of userspace utilities to use the blktrace facility. Configuration is done thru sysfs, adding a "trace" directory to the partition directory where blktrace can be enabled for the associated request_queue. The same filters present in the IOCTL interface are present as sysfs device attributes. The /sys/block/sdX/sdXN/trace/enable file allows tracing without any filters. The other files in this directory: pid, act_mask, start_lba and end_lba can be used with the same meaning as with the IOCTL interface. Using the sysfs interface will only setup the request_queue->blk_trace fields, tracing will only take place when the "blk" tracer is selected via the ftrace interface, as in the following example: To see the trace, one can use the /d/tracing/trace file or the /d/tracign/trace_pipe file, with semantics defined in the ftrace documentation in Documentation/ftrace.txt. [root@f10-1 ~]# cat /t/trace kjournald-305 [000] 3046.491224: 8,1 A WBS 6367 + 8 <- (8,1) 6304 kjournald-305 [000] 3046.491227: 8,1 Q R 6367 + 8 [kjournald] kjournald-305 [000] 3046.491236: 8,1 G RB 6367 + 8 [kjournald] kjournald-305 [000] 3046.491239: 8,1 P NS [kjournald] kjournald-305 [000] 3046.491242: 8,1 I RBS 6367 + 8 [kjournald] kjournald-305 [000] 3046.491251: 8,1 D WB 6367 + 8 [kjournald] kjournald-305 [000] 3046.491610: 8,1 U WS [kjournald] 1 <idle>-0 [000] 3046.511914: 8,1 C RS 6367 + 8 [6367] [root@f10-1 ~]# The default line context (prefix) format is the one described in the ftrace documentation, with the blktrace specific bits using its existing format, described in blkparse(8). If one wants to have the classic blktrace formatting, this is possible by using: [root@f10-1 ~]# echo blk_classic > /t/trace_options [root@f10-1 ~]# cat /t/trace 8,1 0 3046.491224 305 A WBS 6367 + 8 <- (8,1) 6304 8,1 0 3046.491227 305 Q R 6367 + 8 [kjournald] 8,1 0 3046.491236 305 G RB 6367 + 8 [kjournald] 8,1 0 3046.491239 305 P NS [kjournald] 8,1 0 3046.491242 305 I RBS 6367 + 8 [kjournald] 8,1 0 3046.491251 305 D WB 6367 + 8 [kjournald] 8,1 0 3046.491610 305 U WS [kjournald] 1 8,1 0 3046.511914 0 C RS 6367 + 8 [6367] [root@f10-1 ~]# Using the ftrace standard format allows more flexibility, such as the ability of asking for backtraces via trace_options: [root@f10-1 ~]# echo noblk_classic > /t/trace_options [root@f10-1 ~]# echo stacktrace > /t/trace_options [root@f10-1 ~]# cat /t/trace kjournald-305 [000] 3318.826779: 8,1 A WBS 6375 + 8 <- (8,1) 6312 kjournald-305 [000] 3318.826782: <= submit_bio <= submit_bh <= sync_dirty_buffer <= journal_commit_transaction <= kjournald <= kthread <= child_rip kjournald-305 [000] 3318.826836: 8,1 Q R 6375 + 8 [kjournald] kjournald-305 [000] 3318.826837: <= generic_make_request <= submit_bio <= submit_bh <= sync_dirty_buffer <= journal_commit_transaction <= kjournald <= kthread Please read the ftrace documentation to use aditional, standardized tracing filters such as /d/tracing/trace_cpumask, etc. See also /d/tracing/trace_mark to add comments in the trace stream, that is equivalent to the /d/block/sdaN/msg interface. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-08Merge branch 'for_linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 * 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (57 commits) jbd2: Fix oops in jbd2_journal_init_inode() on corrupted fs ext4: Remove "extents" mount option block: Add Kconfig help which notes that ext4 needs CONFIG_LBD ext4: Make printk's consistently prefixed with "EXT4-fs: " ext4: Add sanity checks for the superblock before mounting the filesystem ext4: Add mount option to set kjournald's I/O priority jbd2: Submit writes to the journal using WRITE_SYNC jbd2: Add pid and journal device name to the "kjournald2 starting" message ext4: Add markers for better debuggability ext4: Remove code to create the journal inode ext4: provide function to release metadata pages under memory pressure ext3: provide function to release metadata pages under memory pressure add releasepage hooks to block devices which can be used by file systems ext4: Fix s_dirty_blocks_counter if block allocation failed with nodelalloc ext4: Init the complete page while building buddy cache ext4: Don't allow new groups to be added during block allocation ext4: mark the blocks/inode bitmap beyond end of group as used ext4: Use new buffer_head flag to check uninit group bitmaps initialization ext4: Fix the race between read_inode_bitmap() and ext4_new_inode() ext4: code cleanup ...
2009-01-08Merge git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (45 commits) [SCSI] qla2xxx: Update version number to 8.03.00-k1. [SCSI] qla2xxx: Add ISP81XX support. [SCSI] qla2xxx: Use proper request/response queues with MQ instantiations. [SCSI] qla2xxx: Correct MQ-chain information retrieval during a firmware dump. [SCSI] qla2xxx: Collapse EFT/FCE copy procedures during a firmware dump. [SCSI] qla2xxx: Don't pollute kernel logs with ZIO/RIO status messages. [SCSI] qla2xxx: Don't fallback to interrupt-polling during re-initialization with MSI-X enabled. [SCSI] qla2xxx: Remove support for reading/writing HW-event-log. [SCSI] cxgb3i: add missing include [SCSI] scsi_lib: fix DID_RESET status problems [SCSI] fc transport: restore missing dev_loss_tmo callback to LLDD [SCSI] aha152x_cs: Fix regression that keeps driver from using shared interrupts [SCSI] sd: Correctly handle 6-byte commands with DIX [SCSI] sd: DIF: Fix tagging on platforms with signed char [SCSI] sd: DIF: Show app tag on error [SCSI] Fix error handling for DIF/DIX [SCSI] scsi_lib: don't decrement busy counters when inserting commands [SCSI] libsas: fix test for negative unsigned and typos [SCSI] a2091, gvp11: kill warn_unused_result warnings [SCSI] fusion: Move a dereference below a NULL test ... Fixed up trivial conflict due to moving the async part of sd_probe around in the async probes vs using dev_set_name() in naming.
2009-01-06block: Add Kconfig help which notes that ext4 needs CONFIG_LBDTheodore Ts'o
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: Jens Axboe <jens.axboe@oracle.com>
2009-01-06block: struct device - replace bus_id with dev_name(), dev_set_name()Kay Sievers
Cc: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-01-02[SCSI] block: make blk_rq_map_user take a NULL user-space buffer for WRITEFUJITA Tomonori
The commit 818827669d85b84241696ffef2de485db46b0b5e (block: make blk_rq_map_user take a NULL user-space buffer) extended blk_rq_map_user to accept a NULL user-space buffer with a READ command. It was necessary to convert sg to use the block layer mapping API. This patch extends blk_rq_map_user again for a WRITE command. It is necessary to convert st and osst drivers to use the block layer apping API. Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Acked-by: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2009-01-02[SCSI] block: fix the partial mappings with struct rq_map_dataFUJITA Tomonori
This fixes bio_copy_user_iov to properly handle the partial mappings with struct rq_map_data (which only sg uses for now but st and osst will shortly). It adds the offset member to struct rq_map_data and changes blk_rq_map_user to update it so that bio_copy_user_iov can add an appropriate page frame via bio_add_pc_page(). Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Acked-by: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-12-31Merge branch 'master' of ↵Rusty Russell
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6 Conflicts: arch/x86/kernel/io_apic.c
2008-12-30Merge branch 'master' of ↵Rusty Russell
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
2008-12-29cfq-iosched: fix race between exiting queue and exiting taskJens Axboe
Original patch from Nikanth Karthikesan <knikanth@suse.de> When a queue exits the queue lock is taken and cfq_exit_queue() would free all the cic's associated with the queue. But when a task exits, cfq_exit_io_context() gets cic one by one and then locks the associated queue to call __cfq_exit_single_io_context. It looks like between getting a cic from the ioc and locking the queue, the queue might have exited on another cpu. Fix this by rechecking the cfq_io_context queue key inside the queue lock again, and not calling into __cfq_exit_single_io_context() if somebody beat us to it. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-12-29Get rid of CONFIG_LSFJens Axboe
We have two seperate config entries for large devices/files. One is CONFIG_LBD that guards just the devices, the other is CONFIG_LSF that handles large files. This doesn't make a lot of sense, you typically want both or none. So get rid of CONFIG_LSF and change CONFIG_LBD wording to indicate that it covers both. Acked-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-12-29block: make blk_softirq_init() staticRoel Kluin
Sparse asked whether these could be static. Signed-off-by: Roel Kluin <roel.kluin@gmail.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-12-29block: use min_not_zero in blk_queue_stack_limitsFUJITA Tomonori
zero is invalid for max_phys_segments, max_hw_segments, and max_segment_size. It's better to use use min_not_zero instead of min. min() works though (because the commit 0e435ac makes sure that these values are set to the default values, non zero, if a queue is initialized properly). With this patch, blk_queue_stack_limits does the almost same thing that dm's combine_restrictions_low() does. I think that it's easy to remove dm's combine_restrictions_low. Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-12-29block: add one-hit cache for disk partition lookupJens Axboe
disk_map_sector_rcu() returns a partition from a sector offset, which we use for IO statistics on a per-partition basis. The lookup itself is an O(N) list lookup, where N is the number of partitions. This actually hurts performance quite a bit, even on the lower end partitions. On higher numbered partitions, it can get pretty bad. Solve this by adding a one-hit cache for partition lookup. This makes the lookup O(1) for the case where we do most IO to one partition. Even for mixed partition workloads, amortized cost is pretty close to O(1) since the natural IO batching makes the one-hit cache last for lots of IOs. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-12-29cfq-iosched: remove limit of dispatch depth of max 4 times quantumJens Axboe
This basically limits the hardware queue depth to 4*quantum at any point in time, which is 16 with the default settings. As CFQ uses other means to shrink the hardware queue when necessary in the first place, there's really no need for this extra heuristic. Additionally, it ends up hurting performance in some cases. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-12-29block: get rid of elevator_t typedefJens Axboe
Just use struct elevator_queue everywhere instead. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-12-29block: don't use plugging on SSD devicesJens Axboe
We just want to hand the first bits of IO to the device as fast as possible. Gains a few percent on the IOPS rate. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-12-29block: fix empty barrier on write-through w/ ordered tagTejun Heo
Empty barrier on write-through (or no cache) w/ ordered tag has no command to execute and without any command to execute ordered tag is never issued to the device and the ordering is never achieved. Force draining for such cases. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-12-29block: simplify empty barrier implementationTejun Heo
Empty barrier required special handling in __elv_next_request() to complete it without letting the low level driver see it. With previous changes, barrier code is now flexible enough to skip the BAR step using the same barrier sequence selection mechanism. Drop the special handling and mask off q->ordered from start_ordered(). Remove blk_empty_barrier() test which now has no user. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-12-29block: make barrier completion more robustTejun Heo
Barrier completion had the following assumptions. * start_ordered() couldn't finish the whole sequence properly. If all actions are to be skipped, q->ordseq is set correctly but the actual completion was never triggered thus hanging the barrier request. * Drain completion in elv_complete_request() assumed that there's always at least one request in the queue when drain completes. Both assumptions are true but these assumptions need to be removed to improve empty barrier implementation. This patch makes the following changes. * Make start_ordered() use blk_ordered_complete_seq() to mark skipped steps complete and notify __elv_next_request() that it should fetch the next request if the whole barrier has completed inside start_ordered(). * Make drain completion path in elv_complete_request() check whether the queue is empty. Empty queue also indicates drain completion. * While at it, convert 0/1 return from blk_do_ordered() to false/true. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-12-29block: make every barrier action optionalTejun Heo
In all barrier sequences, the barrier write itself was always assumed to be issued and thus didn't have corresponding control flag. This patch adds QUEUE_ORDERED_DO_BAR and unify action mask handling in start_ordered() such that any barrier action can be skipped. This patch doesn't introduce any visible behavior changes. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-12-29block: remove duplicate or unused barrier/discard error pathsTejun Heo
* Because barrier mode can be changed dynamically, whether barrier is supported or not can be determined only when actually issuing the barrier and there is no point in checking it earlier. Drop barrier support check in generic_make_request() and __make_request(), and update comment around the support check in blk_do_ordered(). * There is no reason to check discard support in both generic_make_request() and __make_request(). Drop the check in __make_request(). While at it, move error action block to the end of the function and add unlikely() to q existence test. * Barrier request, be it empty or not, is never passed to low level driver and thus it's meaningless to try to copy back req->sector to bio->bi_sector on error. In addition, the notion of failed sector doesn't make any sense for empty barrier to begin with. Drop the code block from __end_that_request_first(). Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-12-29block: reorganize QUEUE_ORDERED_* constantsTejun Heo
Separate out ordering type (drain,) and action masks (preflush, postflush, fua) from visible ordering mode selectors (QUEUE_ORDERED_*). Ordering types are now named QUEUE_ORDERED_BY_* while action masks are named QUEUE_ORDERED_DO_*. This change is necessary to add QUEUE_ORDERED_DO_BAR and make it optional to improve empty barrier implementation. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-12-29block: use cancel_work_sync() instead of kblockd_flush_work()Cheng Renquan
After many improvements on kblockd_flush_work, it is now identical to cancel_work_sync, so a direct call to cancel_work_sync is suggested. The only difference is that cancel_work_sync is a GPL symbol, so no non-GPL modules anymore. Signed-off-by: Cheng Renquan <crquan@gmail.com> Cc: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-12-29block: Supress Buffer I/O errors when SCSI REQ_QUIET flag setKeith Mannthey
Allow the scsi request REQ_QUIET flag to be propagated to the buffer file system layer. The basic ideas is to pass the flag from the scsi request to the bio (block IO) and then to the buffer layer. The buffer layer can then suppress needless printks. This patch declutters the kernel log by removed the 40-50 (per lun) buffer io error messages seen during a boot in my multipath setup . It is a good chance any real errors will be missed in the "noise" it the logs without this patch. During boot I see blocks of messages like " __ratelimit: 211 callbacks suppressed Buffer I/O error on device sdm, logical block 5242879 Buffer I/O error on device sdm, logical block 5242879 Buffer I/O error on device sdm, logical block 5242847 Buffer I/O error on device sdm, logical block 1 Buffer I/O error on device sdm, logical block 5242878 Buffer I/O error on device sdm, logical block 5242879 Buffer I/O error on device sdm, logical block 5242879 Buffer I/O error on device sdm, logical block 5242879 Buffer I/O error on device sdm, logical block 5242879 Buffer I/O error on device sdm, logical block 5242872 " in my logs. My disk environment is multipath fiber channel using the SCSI_DH_RDAC code and multipathd. This topology includes an "active" and "ghost" path for each lun. IO's to the "ghost" path will never complete and the SCSI layer, via the scsi device handler rdac code, quick returns the IOs to theses paths and sets the REQ_QUIET scsi flag to suppress the scsi layer messages. I am wanting to extend the QUIET behavior to include the buffer file system layer to deal with these errors as well. I have been running this patch for a while now on several boxes without issue. A few runs of bonnie++ show no noticeable difference in performance in my setup. Thanks for John Stultz for the quiet_error finalization. Submitted-by: Keith Mannthey <kmannth@us.ibm.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-12-29block: don't take lock on changing ra_pagesWu Fengguang
There's no need to take queue_lock or kernel_lock when modifying bdi->ra_pages. So remove them. Also remove out of date comment for queue_max_sectors_store(). Signed-off-by: Wu Fengguang <wfg@linux.intel.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>