!Iblock/blk-sysfs.c
!Eblock/blk-settings.c
!Eblock/blk-exec.c
-!Eblock/blk-barrier.c
+!Eblock/blk-flush.c
+!Eblock/blk-lib.c
!Eblock/blk-tag.c
!Iblock/blk-tag.c
!Eblock/blk-integrity.c
00-INDEX
- This file
-barrier.txt
- - I/O Barriers
biodoc.txt
- Notes on the Generic Block Layer Rewrite in Linux 2.5
capability.txt
- Block layer statistics in /sys/block/<dev>/stat
switching-sched.txt
- Switching I/O schedulers at runtime
+writeback_cache_control.txt
+ - Control of volatile write back caches
+++ /dev/null
-I/O Barriers
-============
-Tejun Heo <htejun@gmail.com>, July 22 2005
-
-I/O barrier requests are used to guarantee ordering around the barrier
-requests. Unless you're crazy enough to use disk drives for
-implementing synchronization constructs (wow, sounds interesting...),
-the ordering is meaningful only for write requests for things like
-journal checkpoints. All requests queued before a barrier request
-must be finished (made it to the physical medium) before the barrier
-request is started, and all requests queued after the barrier request
-must be started only after the barrier request is finished (again,
-made it to the physical medium).
-
-In other words, I/O barrier requests have the following two properties.
-
-1. Request ordering
-
-Requests cannot pass the barrier request. Preceding requests are
-processed before the barrier and following requests after.
-
-Depending on what features a drive supports, this can be done in one
-of the following three ways.
-
-i. For devices which have queue depth greater than 1 (TCQ devices) and
-support ordered tags, block layer can just issue the barrier as an
-ordered request and the lower level driver, controller and drive
-itself are responsible for making sure that the ordering constraint is
-met. Most modern SCSI controllers/drives should support this.
-
-NOTE: SCSI ordered tag isn't currently used due to limitation in the
- SCSI midlayer, see the following random notes section.
-
-ii. For devices which have queue depth greater than 1 but don't
-support ordered tags, block layer ensures that the requests preceding
-a barrier request finishes before issuing the barrier request. Also,
-it defers requests following the barrier until the barrier request is
-finished. Older SCSI controllers/drives and SATA drives fall in this
-category.
-
-iii. Devices which have queue depth of 1. This is a degenerate case
-of ii. Just keeping issue order suffices. Ancient SCSI
-controllers/drives and IDE drives are in this category.
-
-2. Forced flushing to physical medium
-
-Again, if you're not gonna do synchronization with disk drives (dang,
-it sounds even more appealing now!), the reason you use I/O barriers
-is mainly to protect filesystem integrity when power failure or some
-other events abruptly stop the drive from operating and possibly make
-the drive lose data in its cache. So, I/O barriers need to guarantee
-that requests actually get written to non-volatile medium in order.
-
-There are four cases,
-
-i. No write-back cache. Keeping requests ordered is enough.
-
-ii. Write-back cache but no flush operation. There's no way to
-guarantee physical-medium commit order. This kind of devices can't to
-I/O barriers.
-
-iii. Write-back cache and flush operation but no FUA (forced unit
-access). We need two cache flushes - before and after the barrier
-request.
-
-iv. Write-back cache, flush operation and FUA. We still need one
-flush to make sure requests preceding a barrier are written to medium,
-but post-barrier flush can be avoided by using FUA write on the
-barrier itself.
-
-
-How to support barrier requests in drivers
-------------------------------------------
-
-All barrier handling is done inside block layer proper. All low level
-drivers have to are implementing its prepare_flush_fn and using one
-the following two functions to indicate what barrier type it supports
-and how to prepare flush requests. Note that the term 'ordered' is
-used to indicate the whole sequence of performing barrier requests
-including draining and flushing.
-
-typedef void (prepare_flush_fn)(struct request_queue *q, struct request *rq);
-
-int blk_queue_ordered(struct request_queue *q, unsigned ordered,
- prepare_flush_fn *prepare_flush_fn);
-
-@q : the queue in question
-@ordered : the ordered mode the driver/device supports
-@prepare_flush_fn : this function should prepare @rq such that it
- flushes cache to physical medium when executed
-
-For example, SCSI disk driver's prepare_flush_fn looks like the
-following.
-
-static void sd_prepare_flush(struct request_queue *q, struct request *rq)
-{
- memset(rq->cmd, 0, sizeof(rq->cmd));
- rq->cmd_type = REQ_TYPE_BLOCK_PC;
- rq->timeout = SD_TIMEOUT;
- rq->cmd[0] = SYNCHRONIZE_CACHE;
- rq->cmd_len = 10;
-}
-
-The following seven ordered modes are supported. The following table
-shows which mode should be used depending on what features a
-device/driver supports. In the leftmost column of table,
-QUEUE_ORDERED_ prefix is omitted from the mode names to save space.
-
-The table is followed by description of each mode. Note that in the
-descriptions of QUEUE_ORDERED_DRAIN*, '=>' is used whereas '->' is
-used for QUEUE_ORDERED_TAG* descriptions. '=>' indicates that the
-preceding step must be complete before proceeding to the next step.
-'->' indicates that the next step can start as soon as the previous
-step is issued.
-
- write-back cache ordered tag flush FUA
------------------------------------------------------------------------
-NONE yes/no N/A no N/A
-DRAIN no no N/A N/A
-DRAIN_FLUSH yes no yes no
-DRAIN_FUA yes no yes yes
-TAG no yes N/A N/A
-TAG_FLUSH yes yes yes no
-TAG_FUA yes yes yes yes
-
-
-QUEUE_ORDERED_NONE
- I/O barriers are not needed and/or supported.
-
- Sequence: N/A
-
-QUEUE_ORDERED_DRAIN
- Requests are ordered by draining the request queue and cache
- flushing isn't needed.
-
- Sequence: drain => barrier
-
-QUEUE_ORDERED_DRAIN_FLUSH
- Requests are ordered by draining the request queue and both
- pre-barrier and post-barrier cache flushings are needed.
-
- Sequence: drain => preflush => barrier => postflush
-
-QUEUE_ORDERED_DRAIN_FUA
- Requests are ordered by draining the request queue and
- pre-barrier cache flushing is needed. By using FUA on barrier
- request, post-barrier flushing can be skipped.
-
- Sequence: drain => preflush => barrier
-
-QUEUE_ORDERED_TAG
- Requests are ordered by ordered tag and cache flushing isn't
- needed.
-
- Sequence: barrier
-
-QUEUE_ORDERED_TAG_FLUSH
- Requests are ordered by ordered tag and both pre-barrier and
- post-barrier cache flushings are needed.
-
- Sequence: preflush -> barrier -> postflush
-
-QUEUE_ORDERED_TAG_FUA
- Requests are ordered by ordered tag and pre-barrier cache
- flushing is needed. By using FUA on barrier request,
- post-barrier flushing can be skipped.
-
- Sequence: preflush -> barrier
-
-
-Random notes/caveats
---------------------
-
-* SCSI layer currently can't use TAG ordering even if the drive,
-controller and driver support it. The problem is that SCSI midlayer
-request dispatch function is not atomic. It releases queue lock and
-switch to SCSI host lock during issue and it's possible and likely to
-happen in time that requests change their relative positions. Once
-this problem is solved, TAG ordering can be enabled.
-
-* Currently, no matter which ordered mode is used, there can be only
-one barrier request in progress. All I/O barriers are held off by
-block layer until the previous I/O barrier is complete. This doesn't
-make any difference for DRAIN ordered devices, but, for TAG ordered
-devices with very high command latency, passing multiple I/O barriers
-to low level *might* be helpful if they are very frequent. Well, this
-certainly is a non-issue. I'm writing this just to make clear that no
-two I/O barrier is ever passed to low-level driver.
-
-* Completion order. Requests in ordered sequence are issued in order
-but not required to finish in order. Barrier implementation can
-handle out-of-order completion of ordered sequence. IOW, the requests
-MUST be processed in order but the hardware/software completion paths
-are allowed to reorder completion notifications - eg. current SCSI
-midlayer doesn't preserve completion order during error handling.
-
-* Requeueing order. Low-level drivers are free to requeue any request
-after they removed it from the request queue with
-blkdev_dequeue_request(). As barrier sequence should be kept in order
-when requeued, generic elevator code takes care of putting requests in
-order around barrier. See blk_ordered_req_seq() and
-ELEVATOR_INSERT_REQUEUE handling in __elv_add_request() for details.
-
-Note that block drivers must not requeue preceding requests while
-completing latter requests in an ordered sequence. Currently, no
-error checking is done against this.
-
-* Error handling. Currently, block layer will report error to upper
-layer if any of requests in an ordered sequence fails. Unfortunately,
-this doesn't seem to be enough. Look at the following request flow.
-QUEUE_ORDERED_TAG_FLUSH is in use.
-
- [0] [1] [2] [3] [pre] [barrier] [post] < [4] [5] [6] ... >
- still in elevator
-
-Let's say request [2], [3] are write requests to update file system
-metadata (journal or whatever) and [barrier] is used to mark that
-those updates are valid. Consider the following sequence.
-
- i. Requests [0] ~ [post] leaves the request queue and enters
- low-level driver.
- ii. After a while, unfortunately, something goes wrong and the
- drive fails [2]. Note that any of [0], [1] and [3] could have
- completed by this time, but [pre] couldn't have been finished
- as the drive must process it in order and it failed before
- processing that command.
- iii. Error handling kicks in and determines that the error is
- unrecoverable and fails [2], and resumes operation.
- iv. [pre] [barrier] [post] gets processed.
- v. *BOOM* power fails
-
-The problem here is that the barrier request is *supposed* to indicate
-that filesystem update requests [2] and [3] made it safely to the
-physical medium and, if the machine crashes after the barrier is
-written, filesystem recovery code can depend on that. Sadly, that
-isn't true in this case anymore. IOW, the success of a I/O barrier
-should also be dependent on success of some of the preceding requests,
-where only upper layer (filesystem) knows what 'some' is.
-
-This can be solved by implementing a way to tell the block layer which
-requests affect the success of the following barrier request and
-making lower lever drivers to resume operation on error only after
-block layer tells it to do so.
-
-As the probability of this happening is very low and the drive should
-be faulty, implementing the fix is probably an overkill. But, still,
-it's there.
-
-* In previous drafts of barrier implementation, there was fallback
-mechanism such that, if FUA or ordered TAG fails, less fancy ordered
-mode can be selected and the failed barrier request is retried
-automatically. The rationale for this feature was that as FUA is
-pretty new in ATA world and ordered tag was never used widely, there
-could be devices which report to support those features but choke when
-actually given such requests.
-
- This was removed for two reasons 1. it's an overkill 2. it's
-impossible to implement properly when TAG ordering is used as low
-level drivers resume after an error automatically. If it's ever
-needed adding it back and modifying low level drivers accordingly
-shouldn't be difficult.
--- /dev/null
+
+Explicit volatile write back cache control
+=====================================
+
+Introduction
+------------
+
+Many storage devices, especially in the consumer market, come with volatile
+write back caches. That means the devices signal I/O completion to the
+operating system before data actually has hit the non-volatile storage. This
+behavior obviously speeds up various workloads, but it means the operating
+system needs to force data out to the non-volatile storage when it performs
+a data integrity operation like fsync, sync or an unmount.
+
+The Linux block layer provides two simple mechanisms that let filesystems
+control the caching behavior of the storage device. These mechanisms are
+a forced cache flush, and the Force Unit Access (FUA) flag for requests.
+
+
+Explicit cache flushes
+----------------------
+
+The REQ_FLUSH flag can be OR ed into the r/w flags of a bio submitted from
+the filesystem and will make sure the volatile cache of the storage device
+has been flushed before the actual I/O operation is started. This explicitly
+guarantees that previously completed write requests are on non-volatile
+storage before the flagged bio starts. In addition the REQ_FLUSH flag can be
+set on an otherwise empty bio structure, which causes only an explicit cache
+flush without any dependent I/O. It is recommend to use
+the blkdev_issue_flush() helper for a pure cache flush.
+
+
+Forced Unit Access
+-----------------
+
+The REQ_FUA flag can be OR ed into the r/w flags of a bio submitted from the
+filesystem and will make sure that I/O completion for this request is only
+signaled after the data has been committed to non-volatile storage.
+
+
+Implementation details for filesystems
+--------------------------------------
+
+Filesystems can simply set the REQ_FLUSH and REQ_FUA bits and do not have to
+worry if the underlying devices need any explicit cache flushing and how
+the Forced Unit Access is implemented. The REQ_FLUSH and REQ_FUA flags
+may both be set on a single bio.
+
+
+Implementation details for make_request_fn based block drivers
+--------------------------------------------------------------
+
+These drivers will always see the REQ_FLUSH and REQ_FUA bits as they sit
+directly below the submit_bio interface. For remapping drivers the REQ_FUA
+bits need to be propagated to underlying devices, and a global flush needs
+to be implemented for bios with the REQ_FLUSH bit set. For real device
+drivers that do not have a volatile cache the REQ_FLUSH and REQ_FUA bits
+on non-empty bios can simply be ignored, and REQ_FLUSH requests without
+data can be completed successfully without doing any work. Drivers for
+devices with volatile caches need to implement the support for these
+flags themselves without any help from the block layer.
+
+
+Implementation details for request_fn based block drivers
+--------------------------------------------------------------
+
+For devices that do not support volatile write caches there is no driver
+support required, the block layer completes empty REQ_FLUSH requests before
+entering the driver and strips off the REQ_FLUSH and REQ_FUA bits from
+requests that have a payload. For devices with volatile write caches the
+driver needs to tell the block layer that it supports flushing caches by
+doing:
+
+ blk_queue_flush(sdkp->disk->queue, REQ_FLUSH);
+
+and handle empty REQ_FLUSH requests in its prep_fn/request_fn. Note that
+REQ_FLUSH requests with a payload are automatically turned into a sequence
+of an empty REQ_FLUSH request followed by the actual write by the block
+layer. For devices that also support the FUA bit the block layer needs
+to be told to pass through the REQ_FUA bit using:
+
+ blk_queue_flush(sdkp->disk->queue, REQ_FLUSH | REQ_FUA);
+
+and the driver must handle write requests that have the REQ_FUA bit set
+in prep_fn/request_fn. If the FUA bit is not natively supported the block
+layer turns it into an empty REQ_FLUSH request after the actual write.
off = out->sector * 512;
/*
- * The block device implements "barriers", where the Guest indicates
- * that it wants all previous writes to occur before this write. We
- * don't have a way of asking our kernel to do a barrier, so we just
- * synchronize all the data in the file. Pretty poor, no?
- */
- if (out->type & VIRTIO_BLK_T_BARRIER)
- fdatasync(vblk->fd);
-
- /*
* In general the virtio block driver is allowed to try SCSI commands.
* It'd be nice if we supported eject, for example, but we don't.
*/
/* Die, bad Guest, die. */
errx(1, "Write past end %llu+%u", off, ret);
}
+
+ wlen = sizeof(*in);
+ *in = (ret >= 0 ? VIRTIO_BLK_S_OK : VIRTIO_BLK_S_IOERR);
+ } else if (out->type & VIRTIO_BLK_T_FLUSH) {
+ /* Flush */
+ ret = fdatasync(vblk->fd);
+ verbose("FLUSH fdatasync: %i\n", ret);
wlen = sizeof(*in);
*in = (ret >= 0 ? VIRTIO_BLK_S_OK : VIRTIO_BLK_S_IOERR);
} else {
}
}
- /*
- * OK, so we noted that it was pretty poor to use an fdatasync as a
- * barrier. But Christoph Hellwig points out that we need a sync
- * *afterwards* as well: "Barriers specify no reordering to the front
- * or the back." And Jens Axboe confirmed it, so here we are:
- */
- if (out->type & VIRTIO_BLK_T_BARRIER)
- fdatasync(vblk->fd);
-
/* Finished that request. */
add_used(vq, head, wlen);
}
vblk->fd = open_or_die(filename, O_RDWR|O_LARGEFILE);
vblk->len = lseek64(vblk->fd, 0, SEEK_END);
- /* We support barriers. */
- add_feature(dev, VIRTIO_BLK_F_BARRIER);
+ /* We support FLUSH. */
+ add_feature(dev, VIRTIO_BLK_F_FLUSH);
/* Tell Guest how many sectors this device has. */
conf.capacity = cpu_to_le64(vblk->len / 512);
#
obj-$(CONFIG_BLOCK) := elevator.o blk-core.o blk-tag.o blk-sysfs.o \
- blk-barrier.o blk-settings.o blk-ioc.o blk-map.o \
+ blk-flush.o blk-settings.o blk-ioc.o blk-map.o \
blk-exec.o blk-merge.o blk-softirq.o blk-timeout.o \
blk-iopoll.o blk-lib.o ioctl.o genhd.o scsi_ioctl.o
+++ /dev/null
-/*
- * Functions related to barrier IO handling
- */
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/bio.h>
-#include <linux/blkdev.h>
-#include <linux/gfp.h>
-
-#include "blk.h"
-
-/**
- * blk_queue_ordered - does this queue support ordered writes
- * @q: the request queue
- * @ordered: one of QUEUE_ORDERED_*
- *
- * Description:
- * For journalled file systems, doing ordered writes on a commit
- * block instead of explicitly doing wait_on_buffer (which is bad
- * for performance) can be a big win. Block drivers supporting this
- * feature should call this function and indicate so.
- *
- **/
-int blk_queue_ordered(struct request_queue *q, unsigned ordered)
-{
- if (ordered != QUEUE_ORDERED_NONE &&
- ordered != QUEUE_ORDERED_DRAIN &&
- ordered != QUEUE_ORDERED_DRAIN_FLUSH &&
- ordered != QUEUE_ORDERED_DRAIN_FUA &&
- ordered != QUEUE_ORDERED_TAG &&
- ordered != QUEUE_ORDERED_TAG_FLUSH &&
- ordered != QUEUE_ORDERED_TAG_FUA) {
- printk(KERN_ERR "blk_queue_ordered: bad value %d\n", ordered);
- return -EINVAL;
- }
-
- q->ordered = ordered;
- q->next_ordered = ordered;
-
- return 0;
-}
-EXPORT_SYMBOL(blk_queue_ordered);
-
-/*
- * Cache flushing for ordered writes handling
- */
-unsigned blk_ordered_cur_seq(struct request_queue *q)
-{
- if (!q->ordseq)
- return 0;
- return 1 << ffz(q->ordseq);
-}
-
-unsigned blk_ordered_req_seq(struct request *rq)
-{
- struct request_queue *q = rq->q;
-
- BUG_ON(q->ordseq == 0);
-
- if (rq == &q->pre_flush_rq)
- return QUEUE_ORDSEQ_PREFLUSH;
- if (rq == &q->bar_rq)
- return QUEUE_ORDSEQ_BAR;
- if (rq == &q->post_flush_rq)
- return QUEUE_ORDSEQ_POSTFLUSH;
-
- /*
- * !fs requests don't need to follow barrier ordering. Always
- * put them at the front. This fixes the following deadlock.
- *
- * http://thread.gmane.org/gmane.linux.kernel/537473
- */
- if (rq->cmd_type != REQ_TYPE_FS)
- return QUEUE_ORDSEQ_DRAIN;
-
- if ((rq->cmd_flags & REQ_ORDERED_COLOR) ==
- (q->orig_bar_rq->cmd_flags & REQ_ORDERED_COLOR))
- return QUEUE_ORDSEQ_DRAIN;
- else
- return QUEUE_ORDSEQ_DONE;
-}
-
-bool blk_ordered_complete_seq(struct request_queue *q, unsigned seq, int error)
-{
- struct request *rq;
-
- if (error && !q->orderr)
- q->orderr = error;
-
- BUG_ON(q->ordseq & seq);
- q->ordseq |= seq;
-
- if (blk_ordered_cur_seq(q) != QUEUE_ORDSEQ_DONE)
- return false;
-
- /*
- * Okay, sequence complete.
- */
- q->ordseq = 0;
- rq = q->orig_bar_rq;
- __blk_end_request_all(rq, q->orderr);
- return true;
-}
-
-static void pre_flush_end_io(struct request *rq, int error)
-{
- elv_completed_request(rq->q, rq);
- blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_PREFLUSH, error);
-}
-
-static void bar_end_io(struct request *rq, int error)
-{
- elv_completed_request(rq->q, rq);
- blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_BAR, error);
-}
-
-static void post_flush_end_io(struct request *rq, int error)
-{
- elv_completed_request(rq->q, rq);
- blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_POSTFLUSH, error);
-}
-
-static void queue_flush(struct request_queue *q, unsigned which)
-{
- struct request *rq;
- rq_end_io_fn *end_io;
-
- if (which == QUEUE_ORDERED_DO_PREFLUSH) {
- rq = &q->pre_flush_rq;
- end_io = pre_flush_end_io;
- } else {
- rq = &q->post_flush_rq;
- end_io = post_flush_end_io;
- }
-
- blk_rq_init(q, rq);
- rq->cmd_type = REQ_TYPE_FS;
- rq->cmd_flags = REQ_HARDBARRIER | REQ_FLUSH;
- rq->rq_disk = q->orig_bar_rq->rq_disk;
- rq->end_io = end_io;
-
- elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
-}
-
-static inline bool start_ordered(struct request_queue *q, struct request **rqp)
-{
- struct request *rq = *rqp;
- unsigned skip = 0;
-
- q->orderr = 0;
- q->ordered = q->next_ordered;
- q->ordseq |= QUEUE_ORDSEQ_STARTED;
-
- /*
- * For an empty barrier, there's no actual BAR request, which
- * in turn makes POSTFLUSH unnecessary. Mask them off.
- */
- if (!blk_rq_sectors(rq)) {
- q->ordered &= ~(QUEUE_ORDERED_DO_BAR |
- QUEUE_ORDERED_DO_POSTFLUSH);
- /*
- * Empty barrier on a write-through device w/ ordered
- * tag has no command to issue and without any command
- * to issue, ordering by tag can't be used. Drain
- * instead.
- */
- if ((q->ordered & QUEUE_ORDERED_BY_TAG) &&
- !(q->ordered & QUEUE_ORDERED_DO_PREFLUSH)) {
- q->ordered &= ~QUEUE_ORDERED_BY_TAG;
- q->ordered |= QUEUE_ORDERED_BY_DRAIN;
- }
- }
-
- /* stash away the original request */
- blk_dequeue_request(rq);
- q->orig_bar_rq = rq;
- rq = NULL;
-
- /*
- * Queue ordered sequence. As we stack them at the head, we
- * need to queue in reverse order. Note that we rely on that
- * no fs request uses ELEVATOR_INSERT_FRONT and thus no fs
- * request gets inbetween ordered sequence.
- */
- if (q->ordered & QUEUE_ORDERED_DO_POSTFLUSH) {
- queue_flush(q, QUEUE_ORDERED_DO_POSTFLUSH);
- rq = &q->post_flush_rq;
- } else
- skip |= QUEUE_ORDSEQ_POSTFLUSH;
-
- if (q->ordered & QUEUE_ORDERED_DO_BAR) {
- rq = &q->bar_rq;
-
- /* initialize proxy request and queue it */
- blk_rq_init(q, rq);
- if (bio_data_dir(q->orig_bar_rq->bio) == WRITE)
- rq->cmd_flags |= REQ_WRITE;
- if (q->ordered & QUEUE_ORDERED_DO_FUA)
- rq->cmd_flags |= REQ_FUA;
- init_request_from_bio(rq, q->orig_bar_rq->bio);
- rq->end_io = bar_end_io;
-
- elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
- } else
- skip |= QUEUE_ORDSEQ_BAR;
-
- if (q->ordered & QUEUE_ORDERED_DO_PREFLUSH) {
- queue_flush(q, QUEUE_ORDERED_DO_PREFLUSH);
- rq = &q->pre_flush_rq;
- } else
- skip |= QUEUE_ORDSEQ_PREFLUSH;
-
- if ((q->ordered & QUEUE_ORDERED_BY_DRAIN) && queue_in_flight(q))
- rq = NULL;
- else
- skip |= QUEUE_ORDSEQ_DRAIN;
-
- *rqp = rq;
-
- /*
- * Complete skipped sequences. If whole sequence is complete,
- * return false to tell elevator that this request is gone.
- */
- return !blk_ordered_complete_seq(q, skip, 0);
-}
-
-bool blk_do_ordered(struct request_queue *q, struct request **rqp)
-{
- struct request *rq = *rqp;
- const int is_barrier = rq->cmd_type == REQ_TYPE_FS &&
- (rq->cmd_flags & REQ_HARDBARRIER);
-
- if (!q->ordseq) {
- if (!is_barrier)
- return true;
-
- if (q->next_ordered != QUEUE_ORDERED_NONE)
- return start_ordered(q, rqp);
- else {
- /*
- * Queue ordering not supported. Terminate
- * with prejudice.
- */
- blk_dequeue_request(rq);
- __blk_end_request_all(rq, -EOPNOTSUPP);
- *rqp = NULL;
- return false;
- }
- }
-
- /*
- * Ordered sequence in progress
- */
-
- /* Special requests are not subject to ordering rules. */
- if (rq->cmd_type != REQ_TYPE_FS &&
- rq != &q->pre_flush_rq && rq != &q->post_flush_rq)
- return true;
-
- if (q->ordered & QUEUE_ORDERED_BY_TAG) {
- /* Ordered by tag. Blocking the next barrier is enough. */
- if (is_barrier && rq != &q->bar_rq)
- *rqp = NULL;
- } else {
- /* Ordered by draining. Wait for turn. */
- WARN_ON(blk_ordered_req_seq(rq) < blk_ordered_cur_seq(q));
- if (blk_ordered_req_seq(rq) > blk_ordered_cur_seq(q))
- *rqp = NULL;
- }
-
- return true;
-}
-
-static void bio_end_empty_barrier(struct bio *bio, int err)
-{
- if (err) {
- if (err == -EOPNOTSUPP)
- set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
- clear_bit(BIO_UPTODATE, &bio->bi_flags);
- }
- if (bio->bi_private)
- complete(bio->bi_private);
- bio_put(bio);
-}
-
-/**
- * blkdev_issue_flush - queue a flush
- * @bdev: blockdev to issue flush for
- * @gfp_mask: memory allocation flags (for bio_alloc)
- * @error_sector: error sector
- * @flags: BLKDEV_IFL_* flags to control behaviour
- *
- * Description:
- * Issue a flush for the block device in question. Caller can supply
- * room for storing the error offset in case of a flush error, if they
- * wish to. If WAIT flag is not passed then caller may check only what
- * request was pushed in some internal queue for later handling.
- */
-int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask,
- sector_t *error_sector, unsigned long flags)
-{
- DECLARE_COMPLETION_ONSTACK(wait);
- struct request_queue *q;
- struct bio *bio;
- int ret = 0;
-
- if (bdev->bd_disk == NULL)
- return -ENXIO;
-
- q = bdev_get_queue(bdev);
- if (!q)
- return -ENXIO;
-
- /*
- * some block devices may not have their queue correctly set up here
- * (e.g. loop device without a backing file) and so issuing a flush
- * here will panic. Ensure there is a request function before issuing
- * the barrier.
- */
- if (!q->make_request_fn)
- return -ENXIO;
-
- bio = bio_alloc(gfp_mask, 0);
- bio->bi_end_io = bio_end_empty_barrier;
- bio->bi_bdev = bdev;
- if (test_bit(BLKDEV_WAIT, &flags))
- bio->bi_private = &wait;
-
- bio_get(bio);
- submit_bio(WRITE_BARRIER, bio);
- if (test_bit(BLKDEV_WAIT, &flags)) {
- wait_for_completion(&wait);
- /*
- * The driver must store the error location in ->bi_sector, if
- * it supports it. For non-stacked drivers, this should be
- * copied from blk_rq_pos(rq).
- */
- if (error_sector)
- *error_sector = bio->bi_sector;
- }
-
- if (bio_flagged(bio, BIO_EOPNOTSUPP))
- ret = -EOPNOTSUPP;
- else if (!bio_flagged(bio, BIO_UPTODATE))
- ret = -EIO;
-
- bio_put(bio);
- return ret;
-}
-EXPORT_SYMBOL(blkdev_issue_flush);
{
struct request_queue *q = rq->q;
- if (&q->bar_rq != rq) {
+ if (&q->flush_rq != rq) {
if (error)
clear_bit(BIO_UPTODATE, &bio->bi_flags);
else if (!test_bit(BIO_UPTODATE, &bio->bi_flags))
if (bio->bi_size == 0)
bio_endio(bio, error);
} else {
-
/*
- * Okay, this is the barrier request in progress, just
- * record the error;
+ * Okay, this is the sequenced flush request in
+ * progress, just record the error;
*/
- if (error && !q->orderr)
- q->orderr = error;
+ if (error && !q->flush_err)
+ q->flush_err = error;
}
}
init_timer(&q->unplug_timer);
setup_timer(&q->timeout, blk_rq_timed_out_timer, (unsigned long) q);
INIT_LIST_HEAD(&q->timeout_list);
+ INIT_LIST_HEAD(&q->pending_flushes);
INIT_WORK(&q->unplug_work, blk_unplug_work);
kobject_init(&q->kobj, &blk_queue_ktype);
}
EXPORT_SYMBOL(blk_insert_request);
-/*
- * add-request adds a request to the linked list.
- * queue lock is held and interrupts disabled, as we muck with the
- * request queue list.
- */
-static inline void add_request(struct request_queue *q, struct request *req)
-{
- drive_stat_acct(req, 1);
-
- /*
- * elevator indicated where it wants this request to be
- * inserted at elevator_merge time
- */
- __elv_add_request(q, req, ELEVATOR_INSERT_SORT, 0);
-}
-
static void part_round_stats_single(int cpu, struct hd_struct *part,
unsigned long now)
{
const bool sync = !!(bio->bi_rw & REQ_SYNC);
const bool unplug = !!(bio->bi_rw & REQ_UNPLUG);
const unsigned long ff = bio->bi_rw & REQ_FAILFAST_MASK;
+ int where = ELEVATOR_INSERT_SORT;
int rw_flags;
- if ((bio->bi_rw & REQ_HARDBARRIER) &&
- (q->next_ordered == QUEUE_ORDERED_NONE)) {
+ /* REQ_HARDBARRIER is no more */
+ if (WARN_ONCE(bio->bi_rw & REQ_HARDBARRIER,
+ "block: HARDBARRIER is deprecated, use FLUSH/FUA instead\n")) {
bio_endio(bio, -EOPNOTSUPP);
return 0;
}
+
/*
* low level driver can indicate that it wants pages above a
* certain limit bounced to low memory (ie for highmem, or even
spin_lock_irq(q->queue_lock);
- if (unlikely((bio->bi_rw & REQ_HARDBARRIER)) || elv_queue_empty(q))
+ if (bio->bi_rw & (REQ_FLUSH | REQ_FUA)) {
+ where = ELEVATOR_INSERT_FRONT;
+ goto get_rq;
+ }
+
+ if (elv_queue_empty(q))
goto get_rq;
el_ret = elv_merge(q, &req, bio);
req->cpu = blk_cpu_to_group(smp_processor_id());
if (queue_should_plug(q) && elv_queue_empty(q))
blk_plug_device(q);
- add_request(q, req);
+
+ /* insert the request into the elevator */
+ drive_stat_acct(req, 1);
+ __elv_add_request(q, req, where, 0);
out:
if (unplug || !queue_should_plug(q))
__generic_unplug_device(q);
if (bio_check_eod(bio, nr_sectors))
goto end_io;
+ /*
+ * Filter flush bio's early so that make_request based
+ * drivers without flush support don't have to worry
+ * about them.
+ */
+ if ((bio->bi_rw & (REQ_FLUSH | REQ_FUA)) && !q->flush_flags) {
+ bio->bi_rw &= ~(REQ_FLUSH | REQ_FUA);
+ if (!nr_sectors) {
+ err = 0;
+ goto end_io;
+ }
+ }
+
if ((bio->bi_rw & REQ_DISCARD) &&
(!blk_queue_discard(q) ||
((bio->bi_rw & REQ_SECURE) &&
static void blk_account_io_done(struct request *req)
{
/*
- * Account IO completion. bar_rq isn't accounted as a normal
- * IO on queueing nor completion. Accounting the containing
- * request is enough.
+ * Account IO completion. flush_rq isn't accounted as a
+ * normal IO on queueing nor completion. Accounting the
+ * containing request is enough.
*/
- if (blk_do_io_stat(req) && req != &req->q->bar_rq) {
+ if (blk_do_io_stat(req) && req != &req->q->flush_rq) {
unsigned long duration = jiffies - req->start_time;
const int rw = rq_data_dir(req);
struct hd_struct *part;
static void __blk_rq_prep_clone(struct request *dst, struct request *src)
{
dst->cpu = src->cpu;
- dst->cmd_flags = (rq_data_dir(src) | REQ_NOMERGE);
- if (src->cmd_flags & REQ_DISCARD)
- dst->cmd_flags |= REQ_DISCARD;
+ dst->cmd_flags = (src->cmd_flags & REQ_CLONE_MASK) | REQ_NOMERGE;
dst->cmd_type = src->cmd_type;
dst->__sector = blk_rq_pos(src);
dst->__data_len = blk_rq_bytes(src);
--- /dev/null
+/*
+ * Functions to sequence FLUSH and FUA writes.
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/bio.h>
+#include <linux/blkdev.h>
+#include <linux/gfp.h>
+
+#include "blk.h"
+
+/* FLUSH/FUA sequences */
+enum {
+ QUEUE_FSEQ_STARTED = (1 << 0), /* flushing in progress */
+ QUEUE_FSEQ_PREFLUSH = (1 << 1), /* pre-flushing in progress */
+ QUEUE_FSEQ_DATA = (1 << 2), /* data write in progress */
+ QUEUE_FSEQ_POSTFLUSH = (1 << 3), /* post-flushing in progress */
+ QUEUE_FSEQ_DONE = (1 << 4),
+};
+
+static struct request *queue_next_fseq(struct request_queue *q);
+
+unsigned blk_flush_cur_seq(struct request_queue *q)
+{
+ if (!q->flush_seq)
+ return 0;
+ return 1 << ffz(q->flush_seq);
+}
+
+static struct request *blk_flush_complete_seq(struct request_queue *q,
+ unsigned seq, int error)
+{
+ struct request *next_rq = NULL;
+
+ if (error && !q->flush_err)
+ q->flush_err = error;
+
+ BUG_ON(q->flush_seq & seq);
+ q->flush_seq |= seq;
+
+ if (blk_flush_cur_seq(q) != QUEUE_FSEQ_DONE) {
+ /* not complete yet, queue the next flush sequence */
+ next_rq = queue_next_fseq(q);
+ } else {
+ /* complete this flush request */
+ __blk_end_request_all(q->orig_flush_rq, q->flush_err);
+ q->orig_flush_rq = NULL;
+ q->flush_seq = 0;
+
+ /* dispatch the next flush if there's one */
+ if (!list_empty(&q->pending_flushes)) {
+ next_rq = list_entry_rq(q->pending_flushes.next);
+ list_move(&next_rq->queuelist, &q->queue_head);
+ }
+ }
+ return next_rq;
+}
+
+static void blk_flush_complete_seq_end_io(struct request_queue *q,
+ unsigned seq, int error)
+{
+ bool was_empty = elv_queue_empty(q);
+ struct request *next_rq;
+
+ next_rq = blk_flush_complete_seq(q, seq, error);
+
+ /*
+ * Moving a request silently to empty queue_head may stall the
+ * queue. Kick the queue in those cases.
+ */
+ if (was_empty && next_rq)
+ __blk_run_queue(q);
+}
+
+static void pre_flush_end_io(struct request *rq, int error)
+{
+ elv_completed_request(rq->q, rq);
+ blk_flush_complete_seq_end_io(rq->q, QUEUE_FSEQ_PREFLUSH, error);
+}
+
+static void flush_data_end_io(struct request *rq, int error)
+{
+ elv_completed_request(rq->q, rq);
+ blk_flush_complete_seq_end_io(rq->q, QUEUE_FSEQ_DATA, error);
+}
+
+static void post_flush_end_io(struct request *rq, int error)
+{
+ elv_completed_request(rq->q, rq);
+ blk_flush_complete_seq_end_io(rq->q, QUEUE_FSEQ_POSTFLUSH, error);
+}
+
+static void init_flush_request(struct request *rq, struct gendisk *disk)
+{
+ rq->cmd_type = REQ_TYPE_FS;
+ rq->cmd_flags = WRITE_FLUSH;
+ rq->rq_disk = disk;
+}
+
+static struct request *queue_next_fseq(struct request_queue *q)
+{
+ struct request *orig_rq = q->orig_flush_rq;
+ struct request *rq = &q->flush_rq;
+
+ blk_rq_init(q, rq);
+
+ switch (blk_flush_cur_seq(q)) {
+ case QUEUE_FSEQ_PREFLUSH:
+ init_flush_request(rq, orig_rq->rq_disk);
+ rq->end_io = pre_flush_end_io;
+ break;
+ case QUEUE_FSEQ_DATA:
+ init_request_from_bio(rq, orig_rq->bio);
+ /*
+ * orig_rq->rq_disk may be different from
+ * bio->bi_bdev->bd_disk if orig_rq got here through
+ * remapping drivers. Make sure rq->rq_disk points
+ * to the same one as orig_rq.
+ */
+ rq->rq_disk = orig_rq->rq_disk;
+ rq->cmd_flags &= ~(REQ_FLUSH | REQ_FUA);
+ rq->cmd_flags |= orig_rq->cmd_flags & (REQ_FLUSH | REQ_FUA);
+ rq->end_io = flush_data_end_io;
+ break;
+ case QUEUE_FSEQ_POSTFLUSH:
+ init_flush_request(rq, orig_rq->rq_disk);
+ rq->end_io = post_flush_end_io;
+ break;
+ default:
+ BUG();
+ }
+
+ elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
+ return rq;
+}
+
+struct request *blk_do_flush(struct request_queue *q, struct request *rq)
+{
+ unsigned int fflags = q->flush_flags; /* may change, cache it */
+ bool has_flush = fflags & REQ_FLUSH, has_fua = fflags & REQ_FUA;
+ bool do_preflush = has_flush && (rq->cmd_flags & REQ_FLUSH);
+ bool do_postflush = has_flush && !has_fua && (rq->cmd_flags & REQ_FUA);
+ unsigned skip = 0;
+
+ /*
+ * Special case. If there's data but flush is not necessary,
+ * the request can be issued directly.
+ *
+ * Flush w/o data should be able to be issued directly too but
+ * currently some drivers assume that rq->bio contains
+ * non-zero data if it isn't NULL and empty FLUSH requests
+ * getting here usually have bio's without data.
+ */
+ if (blk_rq_sectors(rq) && !do_preflush && !do_postflush) {
+ rq->cmd_flags &= ~REQ_FLUSH;
+ if (!has_fua)
+ rq->cmd_flags &= ~REQ_FUA;
+ return rq;
+ }
+
+ /*
+ * Sequenced flushes can't be processed in parallel. If
+ * another one is already in progress, queue for later
+ * processing.
+ */
+ if (q->flush_seq) {
+ list_move_tail(&rq->queuelist, &q->pending_flushes);
+ return NULL;
+ }
+
+ /*
+ * Start a new flush sequence
+ */
+ q->flush_err = 0;
+ q->flush_seq |= QUEUE_FSEQ_STARTED;
+
+ /* adjust FLUSH/FUA of the original request and stash it away */
+ rq->cmd_flags &= ~REQ_FLUSH;
+ if (!has_fua)
+ rq->cmd_flags &= ~REQ_FUA;
+ blk_dequeue_request(rq);
+ q->orig_flush_rq = rq;
+
+ /* skip unneded sequences and return the first one */
+ if (!do_preflush)
+ skip |= QUEUE_FSEQ_PREFLUSH;
+ if (!blk_rq_sectors(rq))
+ skip |= QUEUE_FSEQ_DATA;
+ if (!do_postflush)
+ skip |= QUEUE_FSEQ_POSTFLUSH;
+ return blk_flush_complete_seq(q, skip, 0);
+}
+
+static void bio_end_flush(struct bio *bio, int err)
+{
+ if (err)
+ clear_bit(BIO_UPTODATE, &bio->bi_flags);
+ if (bio->bi_private)
+ complete(bio->bi_private);
+ bio_put(bio);
+}
+
+/**
+ * blkdev_issue_flush - queue a flush
+ * @bdev: blockdev to issue flush for
+ * @gfp_mask: memory allocation flags (for bio_alloc)
+ * @error_sector: error sector
+ *
+ * Description:
+ * Issue a flush for the block device in question. Caller can supply
+ * room for storing the error offset in case of a flush error, if they
+ * wish to. If WAIT flag is not passed then caller may check only what
+ * request was pushed in some internal queue for later handling.
+ */
+int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask,
+ sector_t *error_sector)
+{
+ DECLARE_COMPLETION_ONSTACK(wait);
+ struct request_queue *q;
+ struct bio *bio;
+ int ret = 0;
+
+ if (bdev->bd_disk == NULL)
+ return -ENXIO;
+
+ q = bdev_get_queue(bdev);
+ if (!q)
+ return -ENXIO;
+
+ /*
+ * some block devices may not have their queue correctly set up here
+ * (e.g. loop device without a backing file) and so issuing a flush
+ * here will panic. Ensure there is a request function before issuing
+ * the flush.
+ */
+ if (!q->make_request_fn)
+ return -ENXIO;
+
+ bio = bio_alloc(gfp_mask, 0);
+ bio->bi_end_io = bio_end_flush;
+ bio->bi_bdev = bdev;
+ bio->bi_private = &wait;
+
+ bio_get(bio);
+ submit_bio(WRITE_FLUSH, bio);
+ wait_for_completion(&wait);
+
+ /*
+ * The driver must store the error location in ->bi_sector, if
+ * it supports it. For non-stacked drivers, this should be
+ * copied from blk_rq_pos(rq).
+ */
+ if (error_sector)
+ *error_sector = bio->bi_sector;
+
+ if (!bio_flagged(bio, BIO_UPTODATE))
+ ret = -EIO;
+
+ bio_put(bio);
+ return ret;
+}
+EXPORT_SYMBOL(blkdev_issue_flush);
{
DECLARE_COMPLETION_ONSTACK(wait);
struct request_queue *q = bdev_get_queue(bdev);
- int type = flags & BLKDEV_IFL_BARRIER ?
- DISCARD_BARRIER : DISCARD_NOBARRIER;
+ int type = REQ_WRITE | REQ_DISCARD;
unsigned int max_discard_sectors;
struct bio *bio;
int ret = 0;
max_discard_sectors &= ~(disc_sects - 1);
}
- if (flags & BLKDEV_IFL_SECURE) {
+ if (flags & BLKDEV_DISCARD_SECURE) {
if (!blk_queue_secdiscard(q))
return -EOPNOTSUPP;
- type |= DISCARD_SECURE;
+ type |= REQ_SECURE;
}
while (nr_sects && !ret) {
bio->bi_sector = sector;
bio->bi_end_io = blkdev_discard_end_io;
bio->bi_bdev = bdev;
- if (flags & BLKDEV_IFL_WAIT)
- bio->bi_private = &wait;
+ bio->bi_private = &wait;
if (nr_sects > max_discard_sectors) {
bio->bi_size = max_discard_sectors << 9;
bio_get(bio);
submit_bio(type, bio);
- if (flags & BLKDEV_IFL_WAIT)
- wait_for_completion(&wait);
+ wait_for_completion(&wait);
if (bio_flagged(bio, BIO_EOPNOTSUPP))
ret = -EOPNOTSUPP;
* @sector: start sector
* @nr_sects: number of sectors to write
* @gfp_mask: memory allocation flags (for bio_alloc)
- * @flags: BLKDEV_IFL_* flags to control behaviour
*
* Description:
* Generate and issue number of bios with zerofiled pages.
*/
int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
- sector_t nr_sects, gfp_t gfp_mask, unsigned long flags)
+ sector_t nr_sects, gfp_t gfp_mask)
{
int ret;
struct bio *bio;
bb.wait = &wait;
bb.end_io = NULL;
- if (flags & BLKDEV_IFL_BARRIER) {
- /* issue async barrier before the data */
- ret = blkdev_issue_flush(bdev, gfp_mask, NULL, 0);
- if (ret)
- return ret;
- }
submit:
ret = 0;
while (nr_sects != 0) {
bio->bi_sector = sector;
bio->bi_bdev = bdev;
bio->bi_end_io = bio_batch_end_io;
- if (flags & BLKDEV_IFL_WAIT)
- bio->bi_private = &bb;
+ bio->bi_private = &bb;
while (nr_sects != 0) {
sz = min((sector_t) PAGE_SIZE >> 9 , nr_sects);
issued++;
submit_bio(WRITE, bio);
}
- /*
- * When all data bios are in flight. Send final barrier if requeted.
- */
- if (nr_sects == 0 && flags & BLKDEV_IFL_BARRIER)
- ret = blkdev_issue_flush(bdev, gfp_mask, NULL,
- flags & BLKDEV_IFL_WAIT);
-
- if (flags & BLKDEV_IFL_WAIT)
- /* Wait for bios in-flight */
- while ( issued != atomic_read(&bb.done))
- wait_for_completion(&wait);
+ /* Wait for bios in-flight */
+ while (issued != atomic_read(&bb.done))
+ wait_for_completion(&wait);
if (!test_bit(BIO_UPTODATE, &bb.flags))
/* One of bios in the batch was completed with error.*/
}
EXPORT_SYMBOL(blk_queue_update_dma_alignment);
+/**
+ * blk_queue_flush - configure queue's cache flush capability
+ * @q: the request queue for the device
+ * @flush: 0, REQ_FLUSH or REQ_FLUSH | REQ_FUA
+ *
+ * Tell block layer cache flush capability of @q. If it supports
+ * flushing, REQ_FLUSH should be set. If it supports bypassing
+ * write cache for individual writes, REQ_FUA should be set.
+ */
+void blk_queue_flush(struct request_queue *q, unsigned int flush)
+{
+ WARN_ON_ONCE(flush & ~(REQ_FLUSH | REQ_FUA));
+
+ if (WARN_ON_ONCE(!(flush & REQ_FLUSH) && (flush & REQ_FUA)))
+ flush &= ~REQ_FUA;
+
+ q->flush_flags = flush & (REQ_FLUSH | REQ_FUA);
+}
+EXPORT_SYMBOL_GPL(blk_queue_flush);
+
static int __init blk_settings_init(void)
{
blk_max_low_pfn = max_low_pfn - 1;
*/
#define ELV_ON_HASH(rq) (!hlist_unhashed(&(rq)->hash))
+struct request *blk_do_flush(struct request_queue *q, struct request *rq);
+
static inline struct request *__elv_next_request(struct request_queue *q)
{
struct request *rq;
while (1) {
while (!list_empty(&q->queue_head)) {
rq = list_entry_rq(q->queue_head.next);
- if (blk_do_ordered(q, &rq))
+ if (!(rq->cmd_flags & (REQ_FLUSH | REQ_FUA)) ||
+ rq == &q->flush_rq)
+ return rq;
+ rq = blk_do_flush(q, rq);
+ if (rq)
return rq;
}
void elv_insert(struct request_queue *q, struct request *rq, int where)
{
- struct list_head *pos;
- unsigned ordseq;
int unplug_it = 1;
trace_block_rq_insert(q, rq);
rq->q = q;
switch (where) {
+ case ELEVATOR_INSERT_REQUEUE:
+ /*
+ * Most requeues happen because of a busy condition,
+ * don't force unplug of the queue for that case.
+ * Clear unplug_it and fall through.
+ */
+ unplug_it = 0;
+
case ELEVATOR_INSERT_FRONT:
rq->cmd_flags |= REQ_SOFTBARRIER;
-
list_add(&rq->queuelist, &q->queue_head);
break;
q->elevator->ops->elevator_add_req_fn(q, rq);
break;
- case ELEVATOR_INSERT_REQUEUE:
- /*
- * If ordered flush isn't in progress, we do front
- * insertion; otherwise, requests should be requeued
- * in ordseq order.
- */
- rq->cmd_flags |= REQ_SOFTBARRIER;
-
- /*
- * Most requeues happen because of a busy condition,
- * don't force unplug of the queue for that case.
- */
- unplug_it = 0;
-
- if (q->ordseq == 0) {
- list_add(&rq->queuelist, &q->queue_head);
- break;
- }
-
- ordseq = blk_ordered_req_seq(rq);
-
- list_for_each(pos, &q->queue_head) {
- struct request *pos_rq = list_entry_rq(pos);
- if (ordseq <= blk_ordered_req_seq(pos_rq))
- break;
- }
-
- list_add_tail(&rq->queuelist, pos);
- break;
-
default:
printk(KERN_ERR "%s: bad insertion point %d\n",
__func__, where);
void __elv_add_request(struct request_queue *q, struct request *rq, int where,
int plug)
{
- if (q->ordcolor)
- rq->cmd_flags |= REQ_ORDERED_COLOR;
-
if (rq->cmd_flags & (REQ_SOFTBARRIER | REQ_HARDBARRIER)) {
- /*
- * toggle ordered color
- */
- if (rq->cmd_flags & REQ_HARDBARRIER)
- q->ordcolor ^= 1;
-
- /*
- * barriers implicitly indicate back insertion
- */
- if (where == ELEVATOR_INSERT_SORT)
- where = ELEVATOR_INSERT_BACK;
-
- /*
- * this request is scheduling boundary, update
- * end_sector
- */
+ /* barriers are scheduling boundary, update end_sector */
if (rq->cmd_type == REQ_TYPE_FS ||
(rq->cmd_flags & REQ_DISCARD)) {
q->end_sector = rq_end_sector(rq);
e->ops->elevator_completed_req_fn)
e->ops->elevator_completed_req_fn(q, rq);
}
-
- /*
- * Check if the queue is waiting for fs requests to be
- * drained for flush sequence.
- */
- if (unlikely(q->ordseq)) {
- struct request *next = NULL;
-
- if (!list_empty(&q->queue_head))
- next = list_entry_rq(q->queue_head.next);
-
- if (!queue_in_flight(q) &&
- blk_ordered_cur_seq(q) == QUEUE_ORDSEQ_DRAIN &&
- (!next || blk_ordered_req_seq(next) > QUEUE_ORDSEQ_DRAIN)) {
- blk_ordered_complete_seq(q, QUEUE_ORDSEQ_DRAIN, 0);
- __blk_run_queue(q);
- }
- }
}
#define to_elv(atr) container_of((atr), struct elv_fs_entry, attr)
static int blk_ioctl_discard(struct block_device *bdev, uint64_t start,
uint64_t len, int secure)
{
- unsigned long flags = BLKDEV_IFL_WAIT;
+ unsigned long flags = 0;
if (start & 511)
return -EINVAL;
if (start + len > (bdev->bd_inode->i_size >> 9))
return -EINVAL;
if (secure)
- flags |= BLKDEV_IFL_SECURE;
+ flags |= BLKDEV_DISCARD_SECURE;
return blkdev_issue_discard(bdev, start, len, GFP_KERNEL, flags);
}
if (!brd->brd_queue)
goto out_free_dev;
blk_queue_make_request(brd->brd_queue, brd_make_request);
- blk_queue_ordered(brd->brd_queue, QUEUE_ORDERED_TAG);
blk_queue_max_hw_sectors(brd->brd_queue, 1024);
blk_queue_bounce_limit(brd->brd_queue, BLK_BOUNCE_ANY);
if (test_bit(MD_NO_BARRIER, &mdev->flags))
return;
- r = blkdev_issue_flush(mdev->ldev->md_bdev, GFP_KERNEL, NULL,
- BLKDEV_IFL_WAIT);
+ r = blkdev_issue_flush(mdev->ldev->md_bdev, GFP_KERNEL, NULL);
if (r) {
set_bit(MD_NO_BARRIER, &mdev->flags);
dev_err(DEV, "meta data flush failed with status %d, disabling md-flushes\n", r);
if (mdev->write_ordering >= WO_bdev_flush && get_ldev(mdev)) {
rv = blkdev_issue_flush(mdev->ldev->backing_bdev, GFP_KERNEL,
- NULL, BLKDEV_IFL_WAIT);
+ NULL);
if (rv) {
dev_err(DEV, "local disk flush failed with status %d\n", rv);
/* would rather check on EOPNOTSUPP, but that is not reliable.
pos = ((loff_t) bio->bi_sector << 9) + lo->lo_offset;
if (bio_rw(bio) == WRITE) {
- bool barrier = !!(bio->bi_rw & REQ_HARDBARRIER);
struct file *file = lo->lo_backing_file;
- if (barrier) {
- if (unlikely(!file->f_op->fsync)) {
- ret = -EOPNOTSUPP;
- goto out;
- }
+ /* REQ_HARDBARRIER is deprecated */
+ if (bio->bi_rw & REQ_HARDBARRIER) {
+ ret = -EOPNOTSUPP;
+ goto out;
+ }
+ if (bio->bi_rw & REQ_FLUSH) {
ret = vfs_fsync(file, 0);
- if (unlikely(ret)) {
+ if (unlikely(ret && ret != -EINVAL)) {
ret = -EIO;
goto out;
}
ret = lo_send(lo, bio, pos);
- if (barrier && !ret) {
+ if ((bio->bi_rw & REQ_FUA) && !ret) {
ret = vfs_fsync(file, 0);
- if (unlikely(ret))
+ if (unlikely(ret && ret != -EINVAL))
ret = -EIO;
}
} else
lo->lo_queue->unplug_fn = loop_unplug;
if (!(lo_flags & LO_FLAGS_READ_ONLY) && file->f_op->fsync)
- blk_queue_ordered(lo->lo_queue, QUEUE_ORDERED_DRAIN);
+ blk_queue_flush(lo->lo_queue, REQ_FLUSH);
set_capacity(lo->lo_disk, size);
bd_set_size(bdev, size << 9);
break;
/* filter out block requests we don't understand */
- if (rq->cmd_type != REQ_TYPE_FS &&
- !(rq->cmd_flags & REQ_HARDBARRIER)) {
+ if (rq->cmd_type != REQ_TYPE_FS) {
blk_end_request_all(rq, 0);
continue;
}
blk_queue_stack_limits(q, osd_request_queue(osdev->osd));
blk_queue_prep_rq(q, blk_queue_start_tag);
- blk_queue_ordered(q, QUEUE_ORDERED_DRAIN_FLUSH);
+ blk_queue_flush(q, REQ_FLUSH);
disk->queue = q;
rq->timeout = 60*HZ;
rq->cmd_type = REQ_TYPE_BLOCK_PC;
- rq->cmd_flags |= REQ_HARDBARRIER;
if (cgc->quiet)
rq->cmd_flags |= REQ_QUIET;
blk_queue_dma_alignment(queue, dev->blk_size-1);
blk_queue_logical_block_size(queue, dev->blk_size);
- blk_queue_ordered(queue, QUEUE_ORDERED_DRAIN_FLUSH);
+ blk_queue_flush(queue, REQ_FLUSH);
blk_queue_max_segments(queue, -1);
blk_queue_max_segment_size(queue, dev->bounce_size);
}
}
- if (vbr->req->cmd_flags & REQ_HARDBARRIER)
- vbr->out_hdr.type |= VIRTIO_BLK_T_BARRIER;
-
sg_set_buf(&vblk->sg[out++], &vbr->out_hdr, sizeof(vbr->out_hdr));
/*
vblk->disk->driverfs_dev = &vdev->dev;
index++;
- if (virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH)) {
- /*
- * If the FLUSH feature is supported we do have support for
- * flushing a volatile write cache on the host. Use that
- * to implement write barrier support.
- */
- blk_queue_ordered(q, QUEUE_ORDERED_DRAIN_FLUSH);
- } else if (virtio_has_feature(vdev, VIRTIO_BLK_F_BARRIER)) {
- /*
- * If the BARRIER feature is supported the host expects us
- * to order request by tags. This implies there is not
- * volatile write cache on the host, and that the host
- * never re-orders outstanding I/O. This feature is not
- * useful for real life scenarious and deprecated.
- */
- blk_queue_ordered(q, QUEUE_ORDERED_TAG);
- } else {
- /*
- * If the FLUSH feature is not supported we must assume that
- * the host does not perform any kind of volatile write
- * caching. We still need to drain the queue to provider
- * proper barrier semantics.
- */
- blk_queue_ordered(q, QUEUE_ORDERED_DRAIN);
- }
+ /* configure queue flush support */
+ if (virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH))
+ blk_queue_flush(q, REQ_FLUSH);
/* If disk is read-only in the host, the guest should obey */
if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO))
};
static unsigned int features[] = {
- VIRTIO_BLK_F_BARRIER, VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX,
- VIRTIO_BLK_F_GEOMETRY, VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE,
- VIRTIO_BLK_F_SCSI, VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY
+ VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY,
+ VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE, VIRTIO_BLK_F_SCSI,
+ VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY
};
/*
struct gnttab_free_callback callback;
struct blk_shadow shadow[BLK_RING_SIZE];
unsigned long shadow_free;
- int feature_barrier;
+ unsigned int feature_flush;
int is_ready;
};
}
-static int xlvbd_barrier(struct blkfront_info *info)
+static void xlvbd_flush(struct blkfront_info *info)
{
- int err;
- const char *barrier;
-
- switch (info->feature_barrier) {
- case QUEUE_ORDERED_DRAIN: barrier = "enabled (drain)"; break;
- case QUEUE_ORDERED_TAG: barrier = "enabled (tag)"; break;
- case QUEUE_ORDERED_NONE: barrier = "disabled"; break;
- default: return -EINVAL;
- }
-
- err = blk_queue_ordered(info->rq, info->feature_barrier);
-
- if (err)
- return err;
-
+ blk_queue_flush(info->rq, info->feature_flush);
printk(KERN_INFO "blkfront: %s: barriers %s\n",
- info->gd->disk_name, barrier);
- return 0;
+ info->gd->disk_name,
+ info->feature_flush ? "enabled" : "disabled");
}
info->rq = gd->queue;
info->gd = gd;
- xlvbd_barrier(info);
+ xlvbd_flush(info);
if (vdisk_info & VDISK_READONLY)
set_disk_ro(gd, 1);
printk(KERN_WARNING "blkfront: %s: write barrier op failed\n",
info->gd->disk_name);
error = -EOPNOTSUPP;
- info->feature_barrier = QUEUE_ORDERED_NONE;
- xlvbd_barrier(info);
+ info->feature_flush = 0;
+ xlvbd_flush(info);
}
/* fall through */
case BLKIF_OP_READ:
/*
* If there's no "feature-barrier" defined, then it means
* we're dealing with a very old backend which writes
- * synchronously; draining will do what needs to get done.
+ * synchronously; nothing to do.
*
- * If there are barriers, then we can do full queued writes
- * with tagged barriers.
- *
- * If barriers are not supported, then there's no much we can
- * do, so just set ordering to NONE.
+ * If there are barriers, then we use flush.
*/
- if (err)
- info->feature_barrier = QUEUE_ORDERED_DRAIN;
- else if (barrier)
- info->feature_barrier = QUEUE_ORDERED_TAG;
- else
- info->feature_barrier = QUEUE_ORDERED_NONE;
+ info->feature_flush = 0;
+
+ /*
+ * The driver doesn't properly handled empty flushes, so
+ * lets disable barrier support for now.
+ */
+#if 0
+ if (!err && barrier)
+ info->feature_flush = REQ_FLUSH;
+#endif
err = xlvbd_alloc_gendisk(sectors, info, binfo, sector_size);
if (err) {
return ide_no_data_taskfile(drive, &cmd);
}
-static void update_ordered(ide_drive_t *drive)
+static void update_flush(ide_drive_t *drive)
{
u16 *id = drive->id;
- unsigned ordered = QUEUE_ORDERED_NONE;
+ unsigned flush = 0;
if (drive->dev_flags & IDE_DFLAG_WCACHE) {
unsigned long long capacity;
drive->name, barrier ? "" : "not ");
if (barrier) {
- ordered = QUEUE_ORDERED_DRAIN_FLUSH;
+ flush = REQ_FLUSH;
blk_queue_prep_rq(drive->queue, idedisk_prep_fn);
}
- } else
- ordered = QUEUE_ORDERED_DRAIN;
+ }
- blk_queue_ordered(drive->queue, ordered);
+ blk_queue_flush(drive->queue, flush);
}
ide_devset_get_flag(wcache, IDE_DFLAG_WCACHE);
}
}
- update_ordered(drive);
+ update_flush(drive);
return err;
}
struct request *rq = NULL;
ide_startstop_t startstop;
- /*
- * drive is doing pre-flush, ordered write, post-flush sequence. even
- * though that is 3 requests, it must be seen as a single transaction.
- * we must not preempt this drive until that is complete
- */
- if (blk_queue_flushing(q))
- /*
- * small race where queue could get replugged during
- * the 3-request flush cycle, just yank the plug since
- * we want it to finish asap
- */
- blk_remove_plug(q);
-
spin_unlock_irq(q->queue_lock);
/* HLD do_request() callback might sleep, make sure it's okay */
struct dm_crypt_io *io;
struct crypt_config *cc;
- if (unlikely(bio_empty_barrier(bio))) {
+ if (bio->bi_rw & REQ_FLUSH) {
cc = ti->private;
bio->bi_bdev = cc->dev->bdev;
return DM_MAPIO_REMAPPED;
*/
struct io {
unsigned long error_bits;
- unsigned long eopnotsupp_bits;
atomic_t count;
struct task_struct *sleeper;
struct dm_io_client *client;
*---------------------------------------------------------------*/
static void dec_count(struct io *io, unsigned int region, int error)
{
- if (error) {
+ if (error)
set_bit(region, &io->error_bits);
- if (error == -EOPNOTSUPP)
- set_bit(region, &io->eopnotsupp_bits);
- }
if (atomic_dec_and_test(&io->count)) {
if (io->sleeper)
sector_t remaining = where->count;
/*
- * where->count may be zero if rw holds a write barrier and we
- * need to send a zero-sized barrier.
+ * where->count may be zero if rw holds a flush and we need to
+ * send a zero-sized flush.
*/
do {
/*
*/
for (i = 0; i < num_regions; i++) {
*dp = old_pages;
- if (where[i].count || (rw & REQ_HARDBARRIER))
+ if (where[i].count || (rw & REQ_FLUSH))
do_region(rw, i, where + i, dp, io);
}
return -EIO;
}
-retry:
io->error_bits = 0;
- io->eopnotsupp_bits = 0;
atomic_set(&io->count, 1); /* see dispatch_io() */
io->sleeper = current;
io->client = client;
}
set_current_state(TASK_RUNNING);
- if (io->eopnotsupp_bits && (rw & REQ_HARDBARRIER)) {
- rw &= ~REQ_HARDBARRIER;
- goto retry;
- }
-
if (error_bits)
*error_bits = io->error_bits;
io = mempool_alloc(client->pool, GFP_NOIO);
io->error_bits = 0;
- io->eopnotsupp_bits = 0;
atomic_set(&io->count, 1); /* see dispatch_io() */
io->sleeper = NULL;
io->client = client;
.count = 0,
};
- lc->io_req.bi_rw = WRITE_BARRIER;
+ lc->io_req.bi_rw = WRITE_FLUSH;
return dm_io(&lc->io_req, 1, &null_location, NULL);
}
struct dm_io_region io[ms->nr_mirrors];
struct mirror *m;
struct dm_io_request io_req = {
- .bi_rw = WRITE_BARRIER,
+ .bi_rw = WRITE_FLUSH,
.mem.type = DM_IO_KMEM,
.mem.ptr.bvec = NULL,
.client = ms->io_client,
struct dm_io_region io[ms->nr_mirrors], *dest = io;
struct mirror *m;
struct dm_io_request io_req = {
- .bi_rw = WRITE | (bio->bi_rw & WRITE_BARRIER),
+ .bi_rw = WRITE | (bio->bi_rw & WRITE_FLUSH_FUA),
.mem.type = DM_IO_BVEC,
.mem.ptr.bvec = bio->bi_io_vec + bio->bi_idx,
.notify.fn = write_callback,
bio_list_init(&requeue);
while ((bio = bio_list_pop(writes))) {
- if (unlikely(bio_empty_barrier(bio))) {
+ if (bio->bi_rw & REQ_FLUSH) {
bio_list_add(&sync, bio);
continue;
}
* We need to dec pending if this was a write.
*/
if (rw == WRITE) {
- if (likely(!bio_empty_barrier(bio)))
+ if (!(bio->bi_rw & REQ_FLUSH))
dm_rh_dec(ms->rh, map_context->ll);
return error;
}
struct list_head failed_recovered_regions;
/*
- * If there was a barrier failure no regions can be marked clean.
+ * If there was a flush failure no regions can be marked clean.
*/
- int barrier_failure;
+ int flush_failure;
void *context;
sector_t target_begin;
INIT_LIST_HEAD(&rh->quiesced_regions);
INIT_LIST_HEAD(&rh->recovered_regions);
INIT_LIST_HEAD(&rh->failed_recovered_regions);
- rh->barrier_failure = 0;
+ rh->flush_failure = 0;
rh->region_pool = mempool_create_kmalloc_pool(MIN_REGIONS,
sizeof(struct dm_region));
region_t region = dm_rh_bio_to_region(rh, bio);
int recovering = 0;
- if (bio_empty_barrier(bio)) {
- rh->barrier_failure = 1;
+ if (bio->bi_rw & REQ_FLUSH) {
+ rh->flush_failure = 1;
return;
}
struct bio *bio;
for (bio = bios->head; bio; bio = bio->bi_next) {
- if (bio_empty_barrier(bio))
+ if (bio->bi_rw & REQ_FLUSH)
continue;
rh_inc(rh, dm_rh_bio_to_region(rh, bio));
}
*/
/* do nothing for DM_RH_NOSYNC */
- if (unlikely(rh->barrier_failure)) {
+ if (unlikely(rh->flush_failure)) {
/*
- * If a write barrier failed some time ago, we
+ * If a write flush failed some time ago, we
* don't know whether or not this write made it
* to the disk, so we must resync the device.
*/
/*
* Commit exceptions to disk.
*/
- if (ps->valid && area_io(ps, WRITE_BARRIER))
+ if (ps->valid && area_io(ps, WRITE_FLUSH_FUA))
ps->valid = 0;
/*
chunk_t chunk;
struct dm_snap_pending_exception *pe = NULL;
- if (unlikely(bio_empty_barrier(bio))) {
+ if (bio->bi_rw & REQ_FLUSH) {
bio->bi_bdev = s->cow->bdev;
return DM_MAPIO_REMAPPED;
}
int r = DM_MAPIO_REMAPPED;
chunk_t chunk;
- if (unlikely(bio_empty_barrier(bio))) {
+ if (bio->bi_rw & REQ_FLUSH) {
if (!map_context->target_request_nr)
bio->bi_bdev = s->origin->bdev;
else
struct dm_dev *dev = ti->private;
bio->bi_bdev = dev->bdev;
- if (unlikely(bio_empty_barrier(bio)))
+ if (bio->bi_rw & REQ_FLUSH)
return DM_MAPIO_REMAPPED;
/* Only tell snapshots if this is a write */
uint32_t stripe;
unsigned target_request_nr;
- if (unlikely(bio_empty_barrier(bio))) {
+ if (bio->bi_rw & REQ_FLUSH) {
target_request_nr = map_context->target_request_nr;
BUG_ON(target_request_nr >= sc->stripes);
bio->bi_bdev = sc->stripe[target_request_nr].dev->bdev;
#define DMF_FREEING 3
#define DMF_DELETING 4
#define DMF_NOFLUSH_SUSPENDING 5
-#define DMF_QUEUE_IO_TO_THREAD 6
/*
* Work processed by per-device workqueue.
spinlock_t deferred_lock;
/*
- * An error from the barrier request currently being processed.
- */
- int barrier_error;
-
- /*
- * Protect barrier_error from concurrent endio processing
- * in request-based dm.
- */
- spinlock_t barrier_error_lock;
-
- /*
- * Processing queue (flush/barriers)
+ * Processing queue (flush)
*/
struct workqueue_struct *wq;
- struct work_struct barrier_work;
-
- /* A pointer to the currently processing pre/post flush request */
- struct request *flush_request;
/*
* The current mapping.
/* sysfs handle */
struct kobject kobj;
- /* zero-length barrier that will be cloned and submitted to targets */
- struct bio barrier_bio;
+ /* zero-length flush that will be cloned and submitted to targets */
+ struct bio flush_bio;
};
/*
/*
* After this is decremented the bio must not be touched if it is
- * a barrier.
+ * a flush.
*/
dm_disk(md)->part0.in_flight[rw] = pending =
atomic_dec_return(&md->pending[rw]);
*/
static void queue_io(struct mapped_device *md, struct bio *bio)
{
- down_write(&md->io_lock);
+ unsigned long flags;
- spin_lock_irq(&md->deferred_lock);
+ spin_lock_irqsave(&md->deferred_lock, flags);
bio_list_add(&md->deferred, bio);
- spin_unlock_irq(&md->deferred_lock);
-
- if (!test_and_set_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags))
- queue_work(md->wq, &md->work);
-
- up_write(&md->io_lock);
+ spin_unlock_irqrestore(&md->deferred_lock, flags);
+ queue_work(md->wq, &md->work);
}
/*
* Target requested pushing back the I/O.
*/
spin_lock_irqsave(&md->deferred_lock, flags);
- if (__noflush_suspending(md)) {
- if (!(io->bio->bi_rw & REQ_HARDBARRIER))
- bio_list_add_head(&md->deferred,
- io->bio);
- } else
+ if (__noflush_suspending(md))
+ bio_list_add_head(&md->deferred, io->bio);
+ else
/* noflush suspend was interrupted. */
io->error = -EIO;
spin_unlock_irqrestore(&md->deferred_lock, flags);
io_error = io->error;
bio = io->bio;
+ end_io_acct(io);
+ free_io(md, io);
+
+ if (io_error == DM_ENDIO_REQUEUE)
+ return;
- if (bio->bi_rw & REQ_HARDBARRIER) {
+ if ((bio->bi_rw & REQ_FLUSH) && bio->bi_size) {
/*
- * There can be just one barrier request so we use
- * a per-device variable for error reporting.
- * Note that you can't touch the bio after end_io_acct
- *
- * We ignore -EOPNOTSUPP for empty flush reported by
- * underlying devices. We assume that if the device
- * doesn't support empty barriers, it doesn't need
- * cache flushing commands.
+ * Preflush done for flush with data, reissue
+ * without REQ_FLUSH.
*/
- if (!md->barrier_error &&
- !(bio_empty_barrier(bio) && io_error == -EOPNOTSUPP))
- md->barrier_error = io_error;
- end_io_acct(io);
- free_io(md, io);
+ bio->bi_rw &= ~REQ_FLUSH;
+ queue_io(md, bio);
} else {
- end_io_acct(io);
- free_io(md, io);
-
- if (io_error != DM_ENDIO_REQUEUE) {
- trace_block_bio_complete(md->queue, bio);
-
- bio_endio(bio, io_error);
- }
+ /* done with normal IO or empty flush */
+ trace_block_bio_complete(md->queue, bio);
+ bio_endio(bio, io_error);
}
}
}
blk_update_request(tio->orig, 0, nr_bytes);
}
-static void store_barrier_error(struct mapped_device *md, int error)
-{
- unsigned long flags;
-
- spin_lock_irqsave(&md->barrier_error_lock, flags);
- /*
- * Basically, the first error is taken, but:
- * -EOPNOTSUPP supersedes any I/O error.
- * Requeue request supersedes any I/O error but -EOPNOTSUPP.
- */
- if (!md->barrier_error || error == -EOPNOTSUPP ||
- (md->barrier_error != -EOPNOTSUPP &&
- error == DM_ENDIO_REQUEUE))
- md->barrier_error = error;
- spin_unlock_irqrestore(&md->barrier_error_lock, flags);
-}
-
/*
* Don't touch any member of the md after calling this function because
* the md may be freed in dm_put() at the end of this function.
static void dm_end_request(struct request *clone, int error)
{
int rw = rq_data_dir(clone);
- int run_queue = 1;
- bool is_barrier = clone->cmd_flags & REQ_HARDBARRIER;
struct dm_rq_target_io *tio = clone->end_io_data;
struct mapped_device *md = tio->md;
struct request *rq = tio->orig;
- if (rq->cmd_type == REQ_TYPE_BLOCK_PC && !is_barrier) {
+ if (rq->cmd_type == REQ_TYPE_BLOCK_PC) {
rq->errors = clone->errors;
rq->resid_len = clone->resid_len;
}
free_rq_clone(clone);
-
- if (unlikely(is_barrier)) {
- if (unlikely(error))
- store_barrier_error(md, error);
- run_queue = 0;
- } else
- blk_end_request_all(rq, error);
-
- rq_completed(md, rw, run_queue);
+ blk_end_request_all(rq, error);
+ rq_completed(md, rw, true);
}
static void dm_unprep_request(struct request *rq)
struct request_queue *q = rq->q;
unsigned long flags;
- if (unlikely(clone->cmd_flags & REQ_HARDBARRIER)) {
- /*
- * Barrier clones share an original request.
- * Leave it to dm_end_request(), which handles this special
- * case.
- */
- dm_end_request(clone, DM_ENDIO_REQUEUE);
- return;
- }
-
dm_unprep_request(rq);
spin_lock_irqsave(q->queue_lock, flags);
struct dm_rq_target_io *tio = clone->end_io_data;
struct request *rq = tio->orig;
- if (unlikely(clone->cmd_flags & REQ_HARDBARRIER)) {
- /*
- * Barrier clones share an original request. So can't use
- * softirq_done with the original.
- * Pass the clone to dm_done() directly in this special case.
- * It is safe (even if clone->q->queue_lock is held here)
- * because there is no I/O dispatching during the completion
- * of barrier clone.
- */
- dm_done(clone, error, true);
- return;
- }
-
tio->error = error;
rq->completion_data = clone;
blk_complete_request(rq);
struct dm_rq_target_io *tio = clone->end_io_data;
struct request *rq = tio->orig;
- if (unlikely(clone->cmd_flags & REQ_HARDBARRIER)) {
- /*
- * Barrier clones share an original request.
- * Leave it to dm_end_request(), which handles this special
- * case.
- */
- BUG_ON(error > 0);
- dm_end_request(clone, error);
- return;
- }
-
rq->cmd_flags |= REQ_FAILED;
dm_complete_request(clone, error);
}
}
/*
- * Creates a little bio that is just does part of a bvec.
+ * Creates a little bio that just does part of a bvec.
*/
static struct bio *split_bvec(struct bio *bio, sector_t sector,
unsigned short idx, unsigned int offset,
clone->bi_sector = sector;
clone->bi_bdev = bio->bi_bdev;
- clone->bi_rw = bio->bi_rw & ~REQ_HARDBARRIER;
+ clone->bi_rw = bio->bi_rw;
clone->bi_vcnt = 1;
clone->bi_size = to_bytes(len);
clone->bi_io_vec->bv_offset = offset;
clone = bio_alloc_bioset(GFP_NOIO, bio->bi_max_vecs, bs);
__bio_clone(clone, bio);
- clone->bi_rw &= ~REQ_HARDBARRIER;
clone->bi_destructor = dm_bio_destructor;
clone->bi_sector = sector;
clone->bi_idx = idx;
__issue_target_request(ci, ti, request_nr, len);
}
-static int __clone_and_map_empty_barrier(struct clone_info *ci)
+static int __clone_and_map_empty_flush(struct clone_info *ci)
{
unsigned target_nr = 0;
struct dm_target *ti;
+ BUG_ON(bio_has_data(ci->bio));
while ((ti = dm_table_get_target(ci->map, target_nr++)))
__issue_target_requests(ci, ti, ti->num_flush_requests, 0);
- ci->sector_count = 0;
-
return 0;
}
sector_t len = 0, max;
struct dm_target_io *tio;
- if (unlikely(bio_empty_barrier(bio)))
- return __clone_and_map_empty_barrier(ci);
-
if (unlikely(bio->bi_rw & REQ_DISCARD))
return __clone_and_map_discard(ci);
ci.map = dm_get_live_table(md);
if (unlikely(!ci.map)) {
- if (!(bio->bi_rw & REQ_HARDBARRIER))
- bio_io_error(bio);
- else
- if (!md->barrier_error)
- md->barrier_error = -EIO;
+ bio_io_error(bio);
return;
}
ci.md = md;
- ci.bio = bio;
ci.io = alloc_io(md);
ci.io->error = 0;
atomic_set(&ci.io->io_count, 1);
ci.io->md = md;
spin_lock_init(&ci.io->endio_lock);
ci.sector = bio->bi_sector;
- ci.sector_count = bio_sectors(bio);
- if (unlikely(bio_empty_barrier(bio)))
- ci.sector_count = 1;
ci.idx = bio->bi_idx;
start_io_acct(ci.io);
- while (ci.sector_count && !error)
- error = __clone_and_map(&ci);
+ if (bio->bi_rw & REQ_FLUSH) {
+ ci.bio = &ci.md->flush_bio;
+ ci.sector_count = 0;
+ error = __clone_and_map_empty_flush(&ci);
+ /* dec_pending submits any data associated with flush */
+ } else {
+ ci.bio = bio;
+ ci.sector_count = bio_sectors(bio);
+ while (ci.sector_count && !error)
+ error = __clone_and_map(&ci);
+ }
/* drop the extra reference count */
dec_pending(ci.io, error);
part_stat_add(cpu, &dm_disk(md)->part0, sectors[rw], bio_sectors(bio));
part_stat_unlock();
- /*
- * If we're suspended or the thread is processing barriers
- * we have to queue this io for later.
- */
- if (unlikely(test_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags)) ||
- unlikely(bio->bi_rw & REQ_HARDBARRIER)) {
+ /* if we're suspended, we have to queue this io for later */
+ if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags))) {
up_read(&md->io_lock);
- if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) &&
- bio_rw(bio) == READA) {
+ if (bio_rw(bio) != READA)
+ queue_io(md, bio);
+ else
bio_io_error(bio);
- return 0;
- }
-
- queue_io(md, bio);
-
return 0;
}
return _dm_request(q, bio);
}
-static bool dm_rq_is_flush_request(struct request *rq)
-{
- if (rq->cmd_flags & REQ_FLUSH)
- return true;
- else
- return false;
-}
-
void dm_dispatch_request(struct request *rq)
{
int r;
{
int r;
- if (dm_rq_is_flush_request(rq)) {
- blk_rq_init(NULL, clone);
- clone->cmd_type = REQ_TYPE_FS;
- clone->cmd_flags |= (REQ_HARDBARRIER | WRITE);
- } else {
- r = blk_rq_prep_clone(clone, rq, tio->md->bs, GFP_ATOMIC,
- dm_rq_bio_constructor, tio);
- if (r)
- return r;
-
- clone->cmd = rq->cmd;
- clone->cmd_len = rq->cmd_len;
- clone->sense = rq->sense;
- clone->buffer = rq->buffer;
- }
+ r = blk_rq_prep_clone(clone, rq, tio->md->bs, GFP_ATOMIC,
+ dm_rq_bio_constructor, tio);
+ if (r)
+ return r;
+ clone->cmd = rq->cmd;
+ clone->cmd_len = rq->cmd_len;
+ clone->sense = rq->sense;
+ clone->buffer = rq->buffer;
clone->end_io = end_clone_request;
clone->end_io_data = tio;
struct mapped_device *md = q->queuedata;
struct request *clone;
- if (unlikely(dm_rq_is_flush_request(rq)))
- return BLKPREP_OK;
-
if (unlikely(rq->special)) {
DMWARN("Already has something in rq->special.");
return BLKPREP_KILL;
struct dm_table *map = dm_get_live_table(md);
struct dm_target *ti;
struct request *rq, *clone;
+ sector_t pos;
/*
* For suspend, check blk_queue_stopped() and increment
if (!rq)
goto plug_and_out;
- if (unlikely(dm_rq_is_flush_request(rq))) {
- BUG_ON(md->flush_request);
- md->flush_request = rq;
- blk_start_request(rq);
- queue_work(md->wq, &md->barrier_work);
- goto out;
- }
+ /* always use block 0 to find the target for flushes for now */
+ pos = 0;
+ if (!(rq->cmd_flags & REQ_FLUSH))
+ pos = blk_rq_pos(rq);
+
+ ti = dm_table_find_target(map, pos);
+ BUG_ON(!dm_target_is_valid(ti));
- ti = dm_table_find_target(map, blk_rq_pos(rq));
if (ti->type->busy && ti->type->busy(ti))
goto plug_and_out;
static const struct block_device_operations dm_blk_dops;
static void dm_wq_work(struct work_struct *work);
-static void dm_rq_barrier_work(struct work_struct *work);
static void dm_init_md_queue(struct mapped_device *md)
{
blk_queue_bounce_limit(md->queue, BLK_BOUNCE_ANY);
md->queue->unplug_fn = dm_unplug_all;
blk_queue_merge_bvec(md->queue, dm_merge_bvec);
+ blk_queue_flush(md->queue, REQ_FLUSH | REQ_FUA);
}
/*
mutex_init(&md->suspend_lock);
mutex_init(&md->type_lock);
spin_lock_init(&md->deferred_lock);
- spin_lock_init(&md->barrier_error_lock);
rwlock_init(&md->map_lock);
atomic_set(&md->holders, 1);
atomic_set(&md->open_count, 0);
atomic_set(&md->pending[1], 0);
init_waitqueue_head(&md->wait);
INIT_WORK(&md->work, dm_wq_work);
- INIT_WORK(&md->barrier_work, dm_rq_barrier_work);
init_waitqueue_head(&md->eventq);
md->disk->major = _major;
if (!md->bdev)
goto bad_bdev;
+ bio_init(&md->flush_bio);
+ md->flush_bio.bi_bdev = md->bdev;
+ md->flush_bio.bi_rw = WRITE_FLUSH;
+
/* Populate the mapping, nobody knows we exist yet */
spin_lock(&_minor_lock);
old_md = idr_replace(&_minor_idr, md, minor);
blk_queue_softirq_done(md->queue, dm_softirq_done);
blk_queue_prep_rq(md->queue, dm_prep_fn);
blk_queue_lld_busy(md->queue, dm_lld_busy);
- blk_queue_ordered(md->queue, QUEUE_ORDERED_DRAIN_FLUSH);
elv_register_queue(md->queue);
return r;
}
-static void dm_flush(struct mapped_device *md)
-{
- dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE);
-
- bio_init(&md->barrier_bio);
- md->barrier_bio.bi_bdev = md->bdev;
- md->barrier_bio.bi_rw = WRITE_BARRIER;
- __split_and_process_bio(md, &md->barrier_bio);
-
- dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE);
-}
-
-static void process_barrier(struct mapped_device *md, struct bio *bio)
-{
- md->barrier_error = 0;
-
- dm_flush(md);
-
- if (!bio_empty_barrier(bio)) {
- __split_and_process_bio(md, bio);
- /*
- * If the request isn't supported, don't waste time with
- * the second flush.
- */
- if (md->barrier_error != -EOPNOTSUPP)
- dm_flush(md);
- }
-
- if (md->barrier_error != DM_ENDIO_REQUEUE)
- bio_endio(bio, md->barrier_error);
- else {
- spin_lock_irq(&md->deferred_lock);
- bio_list_add_head(&md->deferred, bio);
- spin_unlock_irq(&md->deferred_lock);
- }
-}
-
/*
* Process the deferred bios
*/
work);
struct bio *c;
- down_write(&md->io_lock);
+ down_read(&md->io_lock);
while (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) {
spin_lock_irq(&md->deferred_lock);
c = bio_list_pop(&md->deferred);
spin_unlock_irq(&md->deferred_lock);
- if (!c) {
- clear_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags);
+ if (!c)
break;
- }
- up_write(&md->io_lock);
+ up_read(&md->io_lock);
if (dm_request_based(md))
generic_make_request(c);
- else {
- if (c->bi_rw & REQ_HARDBARRIER)
- process_barrier(md, c);
- else
- __split_and_process_bio(md, c);
- }
+ else
+ __split_and_process_bio(md, c);
- down_write(&md->io_lock);
+ down_read(&md->io_lock);
}
- up_write(&md->io_lock);
+ up_read(&md->io_lock);
}
static void dm_queue_flush(struct mapped_device *md)
queue_work(md->wq, &md->work);
}
-static void dm_rq_set_target_request_nr(struct request *clone, unsigned request_nr)
-{
- struct dm_rq_target_io *tio = clone->end_io_data;
-
- tio->info.target_request_nr = request_nr;
-}
-
-/* Issue barrier requests to targets and wait for their completion. */
-static int dm_rq_barrier(struct mapped_device *md)
-{
- int i, j;
- struct dm_table *map = dm_get_live_table(md);
- unsigned num_targets = dm_table_get_num_targets(map);
- struct dm_target *ti;
- struct request *clone;
-
- md->barrier_error = 0;
-
- for (i = 0; i < num_targets; i++) {
- ti = dm_table_get_target(map, i);
- for (j = 0; j < ti->num_flush_requests; j++) {
- clone = clone_rq(md->flush_request, md, GFP_NOIO);
- dm_rq_set_target_request_nr(clone, j);
- atomic_inc(&md->pending[rq_data_dir(clone)]);
- map_request(ti, clone, md);
- }
- }
-
- dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE);
- dm_table_put(map);
-
- return md->barrier_error;
-}
-
-static void dm_rq_barrier_work(struct work_struct *work)
-{
- int error;
- struct mapped_device *md = container_of(work, struct mapped_device,
- barrier_work);
- struct request_queue *q = md->queue;
- struct request *rq;
- unsigned long flags;
-
- /*
- * Hold the md reference here and leave it at the last part so that
- * the md can't be deleted by device opener when the barrier request
- * completes.
- */
- dm_get(md);
-
- error = dm_rq_barrier(md);
-
- rq = md->flush_request;
- md->flush_request = NULL;
-
- if (error == DM_ENDIO_REQUEUE) {
- spin_lock_irqsave(q->queue_lock, flags);
- blk_requeue_request(q, rq);
- spin_unlock_irqrestore(q->queue_lock, flags);
- } else
- blk_end_request_all(rq, error);
-
- blk_run_queue(q);
-
- dm_put(md);
-}
-
/*
* Swap in a new table, returning the old one for the caller to destroy.
*/
*
* To get all processes out of __split_and_process_bio in dm_request,
* we take the write lock. To prevent any process from reentering
- * __split_and_process_bio from dm_request, we set
- * DMF_QUEUE_IO_TO_THREAD.
- *
- * To quiesce the thread (dm_wq_work), we set DMF_BLOCK_IO_FOR_SUSPEND
- * and call flush_workqueue(md->wq). flush_workqueue will wait until
- * dm_wq_work exits and DMF_BLOCK_IO_FOR_SUSPEND will prevent any
- * further calls to __split_and_process_bio from dm_wq_work.
+ * __split_and_process_bio from dm_request and quiesce the thread
+ * (dm_wq_work), we set BMF_BLOCK_IO_FOR_SUSPEND and call
+ * flush_workqueue(md->wq).
*/
down_write(&md->io_lock);
set_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags);
- set_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags);
up_write(&md->io_lock);
/*
- * Request-based dm uses md->wq for barrier (dm_rq_barrier_work) which
- * can be kicked until md->queue is stopped. So stop md->queue before
- * flushing md->wq.
+ * Stop md->queue before flushing md->wq in case request-based
+ * dm defers requests to md->wq from md->queue.
*/
if (dm_request_based(md))
stop_queue(md->queue);
dev_info_t *tmp_dev;
sector_t start_sector;
- if (unlikely(bio->bi_rw & REQ_HARDBARRIER)) {
- md_barrier_request(mddev, bio);
+ if (unlikely(bio->bi_rw & REQ_FLUSH)) {
+ md_flush_request(mddev, bio);
return 0;
}
return 0;
}
rcu_read_lock();
- if (mddev->suspended || mddev->barrier) {
+ if (mddev->suspended) {
DEFINE_WAIT(__wait);
for (;;) {
prepare_to_wait(&mddev->sb_wait, &__wait,
TASK_UNINTERRUPTIBLE);
- if (!mddev->suspended && !mddev->barrier)
+ if (!mddev->suspended)
break;
rcu_read_unlock();
schedule();
int mddev_congested(mddev_t *mddev, int bits)
{
- if (mddev->barrier)
- return 1;
return mddev->suspended;
}
EXPORT_SYMBOL(mddev_congested);
/*
- * Generic barrier handling for md
+ * Generic flush handling for md
*/
-#define POST_REQUEST_BARRIER ((void*)1)
-
-static void md_end_barrier(struct bio *bio, int err)
+static void md_end_flush(struct bio *bio, int err)
{
mdk_rdev_t *rdev = bio->bi_private;
mddev_t *mddev = rdev->mddev;
- if (err == -EOPNOTSUPP && mddev->barrier != POST_REQUEST_BARRIER)
- set_bit(BIO_EOPNOTSUPP, &mddev->barrier->bi_flags);
rdev_dec_pending(rdev, mddev);
if (atomic_dec_and_test(&mddev->flush_pending)) {
- if (mddev->barrier == POST_REQUEST_BARRIER) {
- /* This was a post-request barrier */
- mddev->barrier = NULL;
- wake_up(&mddev->sb_wait);
- } else
- /* The pre-request barrier has finished */
- schedule_work(&mddev->barrier_work);
+ /* The pre-request flush has finished */
+ schedule_work(&mddev->flush_work);
}
bio_put(bio);
}
-static void submit_barriers(mddev_t *mddev)
+static void submit_flushes(mddev_t *mddev)
{
mdk_rdev_t *rdev;
atomic_inc(&rdev->nr_pending);
rcu_read_unlock();
bi = bio_alloc(GFP_KERNEL, 0);
- bi->bi_end_io = md_end_barrier;
+ bi->bi_end_io = md_end_flush;
bi->bi_private = rdev;
bi->bi_bdev = rdev->bdev;
atomic_inc(&mddev->flush_pending);
- submit_bio(WRITE_BARRIER, bi);
+ submit_bio(WRITE_FLUSH, bi);
rcu_read_lock();
rdev_dec_pending(rdev, mddev);
}
rcu_read_unlock();
}
-static void md_submit_barrier(struct work_struct *ws)
+static void md_submit_flush_data(struct work_struct *ws)
{
- mddev_t *mddev = container_of(ws, mddev_t, barrier_work);
- struct bio *bio = mddev->barrier;
+ mddev_t *mddev = container_of(ws, mddev_t, flush_work);
+ struct bio *bio = mddev->flush_bio;
atomic_set(&mddev->flush_pending, 1);
- if (test_bit(BIO_EOPNOTSUPP, &bio->bi_flags))
- bio_endio(bio, -EOPNOTSUPP);
- else if (bio->bi_size == 0)
+ if (bio->bi_size == 0)
/* an empty barrier - all done */
bio_endio(bio, 0);
else {
- bio->bi_rw &= ~REQ_HARDBARRIER;
+ bio->bi_rw &= ~REQ_FLUSH;
if (mddev->pers->make_request(mddev, bio))
generic_make_request(bio);
- mddev->barrier = POST_REQUEST_BARRIER;
- submit_barriers(mddev);
}
if (atomic_dec_and_test(&mddev->flush_pending)) {
- mddev->barrier = NULL;
+ mddev->flush_bio = NULL;
wake_up(&mddev->sb_wait);
}
}
-void md_barrier_request(mddev_t *mddev, struct bio *bio)
+void md_flush_request(mddev_t *mddev, struct bio *bio)
{
spin_lock_irq(&mddev->write_lock);
wait_event_lock_irq(mddev->sb_wait,
- !mddev->barrier,
+ !mddev->flush_bio,
mddev->write_lock, /*nothing*/);
- mddev->barrier = bio;
+ mddev->flush_bio = bio;
spin_unlock_irq(&mddev->write_lock);
atomic_set(&mddev->flush_pending, 1);
- INIT_WORK(&mddev->barrier_work, md_submit_barrier);
+ INIT_WORK(&mddev->flush_work, md_submit_flush_data);
- submit_barriers(mddev);
+ submit_flushes(mddev);
if (atomic_dec_and_test(&mddev->flush_pending))
- schedule_work(&mddev->barrier_work);
+ schedule_work(&mddev->flush_work);
}
-EXPORT_SYMBOL(md_barrier_request);
+EXPORT_SYMBOL(md_flush_request);
/* Support for plugging.
* This mirrors the plugging support in request_queue, but does not
bio_put(bio);
}
-static void super_written_barrier(struct bio *bio, int error)
-{
- struct bio *bio2 = bio->bi_private;
- mdk_rdev_t *rdev = bio2->bi_private;
- mddev_t *mddev = rdev->mddev;
-
- if (!test_bit(BIO_UPTODATE, &bio->bi_flags) &&
- error == -EOPNOTSUPP) {
- unsigned long flags;
- /* barriers don't appear to be supported :-( */
- set_bit(BarriersNotsupp, &rdev->flags);
- mddev->barriers_work = 0;
- spin_lock_irqsave(&mddev->write_lock, flags);
- bio2->bi_next = mddev->biolist;
- mddev->biolist = bio2;
- spin_unlock_irqrestore(&mddev->write_lock, flags);
- wake_up(&mddev->sb_wait);
- bio_put(bio);
- } else {
- bio_put(bio2);
- bio->bi_private = rdev;
- super_written(bio, error);
- }
-}
-
void md_super_write(mddev_t *mddev, mdk_rdev_t *rdev,
sector_t sector, int size, struct page *page)
{
* and decrement it on completion, waking up sb_wait
* if zero is reached.
* If an error occurred, call md_error
- *
- * As we might need to resubmit the request if REQ_HARDBARRIER
- * causes ENOTSUPP, we allocate a spare bio...
*/
struct bio *bio = bio_alloc(GFP_NOIO, 1);
- int rw = REQ_WRITE | REQ_SYNC | REQ_UNPLUG;
bio->bi_bdev = rdev->bdev;
bio->bi_sector = sector;
bio_add_page(bio, page, size, 0);
bio->bi_private = rdev;
bio->bi_end_io = super_written;
- bio->bi_rw = rw;
atomic_inc(&mddev->pending_writes);
- if (!test_bit(BarriersNotsupp, &rdev->flags)) {
- struct bio *rbio;
- rw |= REQ_HARDBARRIER;
- rbio = bio_clone(bio, GFP_NOIO);
- rbio->bi_private = bio;
- rbio->bi_end_io = super_written_barrier;
- submit_bio(rw, rbio);
- } else
- submit_bio(rw, bio);
+ submit_bio(REQ_WRITE | REQ_SYNC | REQ_UNPLUG | REQ_FLUSH | REQ_FUA,
+ bio);
}
void md_super_wait(mddev_t *mddev)
{
- /* wait for all superblock writes that were scheduled to complete.
- * if any had to be retried (due to BARRIER problems), retry them
- */
+ /* wait for all superblock writes that were scheduled to complete */
DEFINE_WAIT(wq);
for(;;) {
prepare_to_wait(&mddev->sb_wait, &wq, TASK_UNINTERRUPTIBLE);
if (atomic_read(&mddev->pending_writes)==0)
break;
- while (mddev->biolist) {
- struct bio *bio;
- spin_lock_irq(&mddev->write_lock);
- bio = mddev->biolist;
- mddev->biolist = bio->bi_next ;
- bio->bi_next = NULL;
- spin_unlock_irq(&mddev->write_lock);
- submit_bio(bio->bi_rw, bio);
- }
schedule();
}
finish_wait(&mddev->sb_wait, &wq);
clear_bit(Faulty, &rdev->flags);
clear_bit(In_sync, &rdev->flags);
clear_bit(WriteMostly, &rdev->flags);
- clear_bit(BarriersNotsupp, &rdev->flags);
if (mddev->raid_disks == 0) {
mddev->major_version = 0;
clear_bit(Faulty, &rdev->flags);
clear_bit(In_sync, &rdev->flags);
clear_bit(WriteMostly, &rdev->flags);
- clear_bit(BarriersNotsupp, &rdev->flags);
if (mddev->raid_disks == 0) {
mddev->major_version = 1;
/* may be over-ridden by personality */
mddev->resync_max_sectors = mddev->dev_sectors;
- mddev->barriers_work = 1;
mddev->ok_start_degraded = start_dirty_degraded;
if (start_readonly && mddev->ro == 0)
mddev->recovery = 0;
mddev->in_sync = 0;
mddev->degraded = 0;
- mddev->barriers_work = 0;
mddev->safemode = 0;
mddev->bitmap_info.offset = 0;
mddev->bitmap_info.default_offset = 0;
#define Faulty 1 /* device is known to have a fault */
#define In_sync 2 /* device is in_sync with rest of array */
#define WriteMostly 4 /* Avoid reading if at all possible */
-#define BarriersNotsupp 5 /* REQ_HARDBARRIER is not supported */
#define AllReserved 6 /* If whole device is reserved for
* one array */
#define AutoDetected 7 /* added by auto-detect */
int degraded; /* whether md should consider
* adding a spare
*/
- int barriers_work; /* initialised to true, cleared as soon
- * as a barrier request to slave
- * fails. Only supported
- */
- struct bio *biolist; /* bios that need to be retried
- * because REQ_HARDBARRIER is not supported
- */
atomic_t recovery_active; /* blocks scheduled, but not written */
wait_queue_head_t recovery_wait;
struct attribute_group *to_remove;
struct plug_handle *plug; /* if used by personality */
- /* Generic barrier handling.
- * If there is a pending barrier request, all other
- * writes are blocked while the devices are flushed.
- * The last to finish a flush schedules a worker to
- * submit the barrier request (without the barrier flag),
- * then submit more flush requests.
+ /* Generic flush handling.
+ * The last to finish preflush schedules a worker to submit
+ * the rest of the request (without the REQ_FLUSH flag).
*/
- struct bio *barrier;
+ struct bio *flush_bio;
atomic_t flush_pending;
- struct work_struct barrier_work;
+ struct work_struct flush_work;
struct work_struct event_work; /* used by dm to report failure event */
};
extern void md_error(mddev_t *mddev, mdk_rdev_t *rdev);
extern int mddev_congested(mddev_t *mddev, int bits);
-extern void md_barrier_request(mddev_t *mddev, struct bio *bio);
+extern void md_flush_request(mddev_t *mddev, struct bio *bio);
extern void md_super_write(mddev_t *mddev, mdk_rdev_t *rdev,
sector_t sector, int size, struct page *page);
extern void md_super_wait(mddev_t *mddev);
struct multipath_bh * mp_bh;
struct multipath_info *multipath;
- if (unlikely(bio->bi_rw & REQ_HARDBARRIER)) {
- md_barrier_request(mddev, bio);
+ if (unlikely(bio->bi_rw & REQ_FLUSH)) {
+ md_flush_request(mddev, bio);
return 0;
}
struct strip_zone *zone;
mdk_rdev_t *tmp_dev;
- if (unlikely(bio->bi_rw & REQ_HARDBARRIER)) {
- md_barrier_request(mddev, bio);
+ if (unlikely(bio->bi_rw & REQ_FLUSH)) {
+ md_flush_request(mddev, bio);
return 0;
}
if (r1_bio->bios[mirror] == bio)
break;
- if (error == -EOPNOTSUPP && test_bit(R1BIO_Barrier, &r1_bio->state)) {
- set_bit(BarriersNotsupp, &conf->mirrors[mirror].rdev->flags);
- set_bit(R1BIO_BarrierRetry, &r1_bio->state);
- r1_bio->mddev->barriers_work = 0;
- /* Don't rdev_dec_pending in this branch - keep it for the retry */
- } else {
+ /*
+ * 'one mirror IO has finished' event handler:
+ */
+ r1_bio->bios[mirror] = NULL;
+ to_put = bio;
+ if (!uptodate) {
+ md_error(r1_bio->mddev, conf->mirrors[mirror].rdev);
+ /* an I/O failed, we can't clear the bitmap */
+ set_bit(R1BIO_Degraded, &r1_bio->state);
+ } else
/*
- * this branch is our 'one mirror IO has finished' event handler:
+ * Set R1BIO_Uptodate in our master bio, so that we
+ * will return a good error code for to the higher
+ * levels even if IO on some other mirrored buffer
+ * fails.
+ *
+ * The 'master' represents the composite IO operation
+ * to user-side. So if something waits for IO, then it
+ * will wait for the 'master' bio.
*/
- r1_bio->bios[mirror] = NULL;
- to_put = bio;
- if (!uptodate) {
- md_error(r1_bio->mddev, conf->mirrors[mirror].rdev);
- /* an I/O failed, we can't clear the bitmap */
- set_bit(R1BIO_Degraded, &r1_bio->state);
- } else
- /*
- * Set R1BIO_Uptodate in our master bio, so that
- * we will return a good error code for to the higher
- * levels even if IO on some other mirrored buffer fails.
- *
- * The 'master' represents the composite IO operation to
- * user-side. So if something waits for IO, then it will
- * wait for the 'master' bio.
- */
- set_bit(R1BIO_Uptodate, &r1_bio->state);
-
- update_head_pos(mirror, r1_bio);
-
- if (behind) {
- if (test_bit(WriteMostly, &conf->mirrors[mirror].rdev->flags))
- atomic_dec(&r1_bio->behind_remaining);
-
- /* In behind mode, we ACK the master bio once the I/O has safely
- * reached all non-writemostly disks. Setting the Returned bit
- * ensures that this gets done only once -- we don't ever want to
- * return -EIO here, instead we'll wait */
-
- if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) &&
- test_bit(R1BIO_Uptodate, &r1_bio->state)) {
- /* Maybe we can return now */
- if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
- struct bio *mbio = r1_bio->master_bio;
- PRINTK(KERN_DEBUG "raid1: behind end write sectors %llu-%llu\n",
- (unsigned long long) mbio->bi_sector,
- (unsigned long long) mbio->bi_sector +
- (mbio->bi_size >> 9) - 1);
- bio_endio(mbio, 0);
- }
+ set_bit(R1BIO_Uptodate, &r1_bio->state);
+
+ update_head_pos(mirror, r1_bio);
+
+ if (behind) {
+ if (test_bit(WriteMostly, &conf->mirrors[mirror].rdev->flags))
+ atomic_dec(&r1_bio->behind_remaining);
+
+ /*
+ * In behind mode, we ACK the master bio once the I/O
+ * has safely reached all non-writemostly
+ * disks. Setting the Returned bit ensures that this
+ * gets done only once -- we don't ever want to return
+ * -EIO here, instead we'll wait
+ */
+ if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) &&
+ test_bit(R1BIO_Uptodate, &r1_bio->state)) {
+ /* Maybe we can return now */
+ if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
+ struct bio *mbio = r1_bio->master_bio;
+ PRINTK(KERN_DEBUG "raid1: behind end write sectors %llu-%llu\n",
+ (unsigned long long) mbio->bi_sector,
+ (unsigned long long) mbio->bi_sector +
+ (mbio->bi_size >> 9) - 1);
+ bio_endio(mbio, 0);
}
}
- rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
}
+ rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
+
/*
- *
* Let's see if all mirrored write operations have finished
* already.
*/
if (atomic_dec_and_test(&r1_bio->remaining)) {
- if (test_bit(R1BIO_BarrierRetry, &r1_bio->state))
- reschedule_retry(r1_bio);
- else {
- /* it really is the end of this request */
- if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
- /* free extra copy of the data pages */
- int i = bio->bi_vcnt;
- while (i--)
- safe_put_page(bio->bi_io_vec[i].bv_page);
- }
- /* clear the bitmap if all writes complete successfully */
- bitmap_endwrite(r1_bio->mddev->bitmap, r1_bio->sector,
- r1_bio->sectors,
- !test_bit(R1BIO_Degraded, &r1_bio->state),
- behind);
- md_write_end(r1_bio->mddev);
- raid_end_bio_io(r1_bio);
+ if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
+ /* free extra copy of the data pages */
+ int i = bio->bi_vcnt;
+ while (i--)
+ safe_put_page(bio->bi_io_vec[i].bv_page);
}
+ /* clear the bitmap if all writes complete successfully */
+ bitmap_endwrite(r1_bio->mddev->bitmap, r1_bio->sector,
+ r1_bio->sectors,
+ !test_bit(R1BIO_Degraded, &r1_bio->state),
+ behind);
+ md_write_end(r1_bio->mddev);
+ raid_end_bio_io(r1_bio);
}
if (to_put)
struct page **behind_pages = NULL;
const int rw = bio_data_dir(bio);
const unsigned long do_sync = (bio->bi_rw & REQ_SYNC);
- unsigned long do_barriers;
+ const unsigned long do_flush_fua = (bio->bi_rw & (REQ_FLUSH | REQ_FUA));
mdk_rdev_t *blocked_rdev;
/*
* Register the new request and wait if the reconstruction
* thread has put up a bar for new requests.
* Continue immediately if no resync is active currently.
- * We test barriers_work *after* md_write_start as md_write_start
- * may cause the first superblock write, and that will check out
- * if barriers work.
*/
md_write_start(mddev, bio); /* wait on superblock update early */
}
finish_wait(&conf->wait_barrier, &w);
}
- if (unlikely(!mddev->barriers_work &&
- (bio->bi_rw & REQ_HARDBARRIER))) {
- if (rw == WRITE)
- md_write_end(mddev);
- bio_endio(bio, -EOPNOTSUPP);
- return 0;
- }
wait_barrier(conf);
atomic_set(&r1_bio->remaining, 0);
atomic_set(&r1_bio->behind_remaining, 0);
- do_barriers = bio->bi_rw & REQ_HARDBARRIER;
- if (do_barriers)
- set_bit(R1BIO_Barrier, &r1_bio->state);
-
bio_list_init(&bl);
for (i = 0; i < disks; i++) {
struct bio *mbio;
mbio->bi_sector = r1_bio->sector + conf->mirrors[i].rdev->data_offset;
mbio->bi_bdev = conf->mirrors[i].rdev->bdev;
mbio->bi_end_io = raid1_end_write_request;
- mbio->bi_rw = WRITE | do_barriers | do_sync;
+ mbio->bi_rw = WRITE | do_flush_fua | do_sync;
mbio->bi_private = r1_bio;
if (behind_pages) {
if (test_bit(R1BIO_IsSync, &r1_bio->state)) {
sync_request_write(mddev, r1_bio);
unplug = 1;
- } else if (test_bit(R1BIO_BarrierRetry, &r1_bio->state)) {
- /* some requests in the r1bio were REQ_HARDBARRIER
- * requests which failed with -EOPNOTSUPP. Hohumm..
- * Better resubmit without the barrier.
- * We know which devices to resubmit for, because
- * all others have had their bios[] entry cleared.
- * We already have a nr_pending reference on these rdevs.
- */
- int i;
- const unsigned long do_sync = (r1_bio->master_bio->bi_rw & REQ_SYNC);
- clear_bit(R1BIO_BarrierRetry, &r1_bio->state);
- clear_bit(R1BIO_Barrier, &r1_bio->state);
- for (i=0; i < conf->raid_disks; i++)
- if (r1_bio->bios[i])
- atomic_inc(&r1_bio->remaining);
- for (i=0; i < conf->raid_disks; i++)
- if (r1_bio->bios[i]) {
- struct bio_vec *bvec;
- int j;
-
- bio = bio_clone(r1_bio->master_bio, GFP_NOIO);
- /* copy pages from the failed bio, as
- * this might be a write-behind device */
- __bio_for_each_segment(bvec, bio, j, 0)
- bvec->bv_page = bio_iovec_idx(r1_bio->bios[i], j)->bv_page;
- bio_put(r1_bio->bios[i]);
- bio->bi_sector = r1_bio->sector +
- conf->mirrors[i].rdev->data_offset;
- bio->bi_bdev = conf->mirrors[i].rdev->bdev;
- bio->bi_end_io = raid1_end_write_request;
- bio->bi_rw = WRITE | do_sync;
- bio->bi_private = r1_bio;
- r1_bio->bios[i] = bio;
- generic_make_request(bio);
- }
} else {
int disk;
#define R1BIO_IsSync 1
#define R1BIO_Degraded 2
#define R1BIO_BehindIO 3
-#define R1BIO_Barrier 4
-#define R1BIO_BarrierRetry 5
/* For write-behind requests, we call bi_end_io when
* the last non-write-behind device completes, providing
* any write was successful. Otherwise we call when
int chunk_sects = conf->chunk_mask + 1;
const int rw = bio_data_dir(bio);
const unsigned long do_sync = (bio->bi_rw & REQ_SYNC);
+ const unsigned long do_fua = (bio->bi_rw & REQ_FUA);
struct bio_list bl;
unsigned long flags;
mdk_rdev_t *blocked_rdev;
- if (unlikely(bio->bi_rw & REQ_HARDBARRIER)) {
- md_barrier_request(mddev, bio);
+ if (unlikely(bio->bi_rw & REQ_FLUSH)) {
+ md_flush_request(mddev, bio);
return 0;
}
conf->mirrors[d].rdev->data_offset;
mbio->bi_bdev = conf->mirrors[d].rdev->bdev;
mbio->bi_end_io = raid10_end_write_request;
- mbio->bi_rw = WRITE | do_sync;
+ mbio->bi_rw = WRITE | do_sync | do_fua;
mbio->bi_private = r10_bio;
atomic_inc(&r10_bio->remaining);
int rw;
struct bio *bi;
mdk_rdev_t *rdev;
- if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags))
- rw = WRITE;
- else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags))
+ if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags)) {
+ if (test_and_clear_bit(R5_WantFUA, &sh->dev[i].flags))
+ rw = WRITE_FUA;
+ else
+ rw = WRITE;
+ } else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags))
rw = READ;
else
continue;
while (wbi && wbi->bi_sector <
dev->sector + STRIPE_SECTORS) {
+ if (wbi->bi_rw & REQ_FUA)
+ set_bit(R5_WantFUA, &dev->flags);
tx = async_copy_data(1, wbi, dev->page,
dev->sector, tx);
wbi = r5_next_bio(wbi, dev->sector);
int pd_idx = sh->pd_idx;
int qd_idx = sh->qd_idx;
int i;
+ bool fua = false;
pr_debug("%s: stripe %llu\n", __func__,
(unsigned long long)sh->sector);
+ for (i = disks; i--; )
+ fua |= test_bit(R5_WantFUA, &sh->dev[i].flags);
+
for (i = disks; i--; ) {
struct r5dev *dev = &sh->dev[i];
- if (dev->written || i == pd_idx || i == qd_idx)
+ if (dev->written || i == pd_idx || i == qd_idx) {
set_bit(R5_UPTODATE, &dev->flags);
+ if (fua)
+ set_bit(R5_WantFUA, &dev->flags);
+ }
}
if (sh->reconstruct_state == reconstruct_state_drain_run)
if (dec_preread_active) {
/* We delay this until after ops_run_io so that if make_request
- * is waiting on a barrier, it won't continue until the writes
+ * is waiting on a flush, it won't continue until the writes
* have actually been submitted.
*/
atomic_dec(&conf->preread_active_stripes);
if (dec_preread_active) {
/* We delay this until after ops_run_io so that if make_request
- * is waiting on a barrier, it won't continue until the writes
+ * is waiting on a flush, it won't continue until the writes
* have actually been submitted.
*/
atomic_dec(&conf->preread_active_stripes);
const int rw = bio_data_dir(bi);
int remaining;
- if (unlikely(bi->bi_rw & REQ_HARDBARRIER)) {
- /* Drain all pending writes. We only really need
- * to ensure they have been submitted, but this is
- * easier.
- */
- mddev->pers->quiesce(mddev, 1);
- mddev->pers->quiesce(mddev, 0);
- md_barrier_request(mddev, bi);
+ if (unlikely(bi->bi_rw & REQ_FLUSH)) {
+ md_flush_request(mddev, bi);
return 0;
}
finish_wait(&conf->wait_for_overlap, &w);
set_bit(STRIPE_HANDLE, &sh->state);
clear_bit(STRIPE_DELAYED, &sh->state);
- if (mddev->barrier &&
+ if ((bi->bi_rw & REQ_SYNC) &&
!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
atomic_inc(&conf->preread_active_stripes);
release_stripe(sh);
bio_endio(bi, 0);
}
- if (mddev->barrier) {
- /* We need to wait for the stripes to all be handled.
- * So: wait for preread_active_stripes to drop to 0.
- */
- wait_event(mddev->thread->wqueue,
- atomic_read(&conf->preread_active_stripes) == 0);
- }
return 0;
}
* filling
*/
#define R5_Wantdrain 13 /* dev->towrite needs to be drained */
+#define R5_WantFUA 14 /* Write should be FUA */
/*
* Write method
*/
mq->req = NULL;
blk_queue_prep_rq(mq->queue, mmc_prep_request);
- blk_queue_ordered(mq->queue, QUEUE_ORDERED_DRAIN);
queue_flag_set_unlocked(QUEUE_FLAG_NONROT, mq->queue);
if (mmc_can_erase(card)) {
queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mq->queue);
*/
blk_queue_max_segment_size(block->request_queue, PAGE_SIZE);
blk_queue_segment_boundary(block->request_queue, PAGE_SIZE - 1);
- blk_queue_ordered(block->request_queue, QUEUE_ORDERED_DRAIN);
}
/*
aic_dev->r_total++;
ptr = aic_dev->r_bins;
}
- if(cmd->device->simple_tags && cmd->request->cmd_flags & REQ_HARDBARRIER)
- {
- aic_dev->barrier_total++;
- if(scb->tag_action == MSG_ORDERED_Q_TAG)
- aic_dev->ordered_total++;
- }
x = scb->sg_length;
x >>= 10;
for(i=0; i<6; i++)
struct aic_dev_data *aic_dev = cmd->device->hostdata;
struct scsi_device *sdptr = cmd->device;
unsigned char tindex = TARGET_INDEX(cmd);
- struct request *req = cmd->request;
int use_sg;
mask = (0x01 << tindex);
/* We always force TEST_UNIT_READY to untagged */
if (cmd->cmnd[0] != TEST_UNIT_READY && sdptr->simple_tags)
{
- if (req->cmd_flags & REQ_HARDBARRIER)
- {
- if(sdptr->ordered_tags)
- {
- hscb->control |= MSG_ORDERED_Q_TAG;
- scb->tag_action = MSG_ORDERED_Q_TAG;
- }
- }
- else
- {
- hscb->control |= MSG_SIMPLE_Q_TAG;
- scb->tag_action = MSG_SIMPLE_Q_TAG;
- }
+ hscb->control |= MSG_SIMPLE_Q_TAG;
+ scb->tag_action = MSG_SIMPLE_Q_TAG;
}
}
if ( !(aic_dev->dtr_pending) &&
sc->scsi_done(sc);
}
-static enum task_attribute sas_scsi_get_task_attr(struct scsi_cmnd *cmd)
-{
- enum task_attribute ta = TASK_ATTR_SIMPLE;
- if (cmd->request && blk_rq_tagged(cmd->request)) {
- if (cmd->device->ordered_tags &&
- (cmd->request->cmd_flags & REQ_HARDBARRIER))
- ta = TASK_ATTR_ORDERED;
- }
- return ta;
-}
-
static struct sas_task *sas_create_task(struct scsi_cmnd *cmd,
struct domain_device *dev,
gfp_t gfp_flags)
task->ssp_task.retry_count = 1;
int_to_scsilun(cmd->device->lun, &lun);
memcpy(task->ssp_task.LUN, &lun.scsi_lun, 8);
- task->ssp_task.task_attr = sas_scsi_get_task_attr(cmd);
+ task->ssp_task.task_attr = TASK_ATTR_SIMPLE;
memcpy(task->ssp_task.cdb, cmd->cmnd, 16);
task->scatter = scsi_sglist(cmd);
struct scsi_disk *sdkp = scsi_disk(disk);
struct scsi_device *sdp = sdkp->device;
unsigned char *buffer;
- unsigned ordered;
+ unsigned flush = 0;
SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp,
"sd_revalidate_disk\n"));
/*
* We now have all cache related info, determine how we deal
- * with ordered requests. Note that as the current SCSI
- * dispatch function can alter request order, we cannot use
- * QUEUE_ORDERED_TAG_* even when ordered tag is supported.
+ * with flush requests.
*/
- if (sdkp->WCE)
- ordered = sdkp->DPOFUA
- ? QUEUE_ORDERED_DRAIN_FUA : QUEUE_ORDERED_DRAIN_FLUSH;
- else
- ordered = QUEUE_ORDERED_DRAIN;
+ if (sdkp->WCE) {
+ flush |= REQ_FLUSH;
+ if (sdkp->DPOFUA)
+ flush |= REQ_FUA;
+ }
- blk_queue_ordered(sdkp->disk->queue, ordered);
+ blk_queue_flush(sdkp->disk->queue, flush);
set_capacity(disk, sdkp->capacity);
kfree(buffer);
*/
mutex_unlock(&bd_inode->i_mutex);
- error = blkdev_issue_flush(bdev, GFP_KERNEL, NULL, BLKDEV_IFL_WAIT);
+ error = blkdev_issue_flush(bdev, GFP_KERNEL, NULL);
if (error == -EOPNOTSUPP)
error = 0;
if (uptodate) {
set_buffer_uptodate(bh);
} else {
- if (!buffer_eopnotsupp(bh) && printk_ratelimit()) {
+ if (printk_ratelimit()) {
printk(KERN_WARNING "lost page write due to "
"I/O error on %s\n",
bdevname(bh->b_bdev, b));
bh->b_end_io = btrfs_end_buffer_write_sync;
}
- if (i == last_barrier && do_barriers && device->barriers) {
- ret = submit_bh(WRITE_BARRIER, bh);
- if (ret == -EOPNOTSUPP) {
- printk("btrfs: disabling barriers on dev %s\n",
- device->name);
- set_buffer_uptodate(bh);
- device->barriers = 0;
- /* one reference for submit_bh */
- get_bh(bh);
- lock_buffer(bh);
- ret = submit_bh(WRITE_SYNC, bh);
- }
- } else {
+ if (i == last_barrier && do_barriers)
+ ret = submit_bh(WRITE_FLUSH_FUA, bh);
+ else
ret = submit_bh(WRITE_SYNC, bh);
- }
if (ret)
errors++;
static void btrfs_issue_discard(struct block_device *bdev,
u64 start, u64 len)
{
- blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_KERNEL,
- BLKDEV_IFL_WAIT | BLKDEV_IFL_BARRIER);
+ blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_KERNEL, 0);
}
static int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
device->work.func = pending_bios_fn;
memcpy(device->uuid, disk_super->dev_item.uuid,
BTRFS_UUID_SIZE);
- device->barriers = 1;
spin_lock_init(&device->io_lock);
device->name = kstrdup(path, GFP_NOFS);
if (!device->name) {
device->devid = orig_dev->devid;
device->work.func = pending_bios_fn;
memcpy(device->uuid, orig_dev->uuid, sizeof(device->uuid));
- device->barriers = 1;
spin_lock_init(&device->io_lock);
INIT_LIST_HEAD(&device->dev_list);
INIT_LIST_HEAD(&device->dev_alloc_list);
trans = btrfs_start_transaction(root, 0);
lock_chunks(root);
- device->barriers = 1;
device->writeable = 1;
device->work.func = pending_bios_fn;
generate_random_uuid(device->uuid);
return NULL;
list_add(&device->dev_list,
&fs_devices->devices);
- device->barriers = 1;
device->dev_root = root->fs_info->dev_root;
device->devid = devid;
device->work.func = pending_bios_fn;
int running_pending;
u64 generation;
- int barriers;
int writeable;
int in_fs_metadata;
if (uptodate) {
set_buffer_uptodate(bh);
} else {
- if (!buffer_eopnotsupp(bh) && !quiet_error(bh)) {
+ if (!quiet_error(bh)) {
buffer_io_error(bh);
printk(KERN_WARNING "lost page write due to "
"I/O error on %s\n",
if (err == -EOPNOTSUPP) {
set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
- set_bit(BH_Eopnotsupp, &bh->b_state);
}
if (unlikely (test_bit(BIO_QUIET,&bio->bi_flags)))
bh->b_end_io = end_buffer_write_sync;
ret = submit_bh(rw, bh);
wait_on_buffer(bh);
- if (buffer_eopnotsupp(bh)) {
- clear_buffer_eopnotsupp(bh);
- ret = -EOPNOTSUPP;
- }
if (!ret && !buffer_uptodate(bh))
ret = -EIO;
} else {
* storage
*/
if (needs_barrier)
- blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL,
- BLKDEV_IFL_WAIT);
+ blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL);
return ret;
}
(journal->j_fs_dev != journal->j_dev) &&
(journal->j_flags & JBD2_BARRIER))
blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL,
- NULL, BLKDEV_IFL_WAIT);
+ NULL);
ret = jbd2_log_wait_commit(journal, commit_tid);
} else if (journal->j_flags & JBD2_BARRIER)
- blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL,
- BLKDEV_IFL_WAIT);
+ blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL);
return ret;
}
discard_block = block + ext4_group_first_block_no(sb, block_group);
trace_ext4_discard_blocks(sb,
(unsigned long long) discard_block, count);
- ret = sb_issue_discard(sb, discard_block, count);
+ ret = sb_issue_discard(sb, discard_block, count, GFP_NOFS, 0);
if (ret == EOPNOTSUPP) {
ext4_warning(sb, "discard not supported, disabling");
clear_opt(EXT4_SB(sb)->s_mount_opt, DISCARD);
sb_issue_discard(sb,
fat_clus_to_blknr(sbi, first_cl),
- nr_clus * sbi->sec_per_clus);
+ nr_clus * sbi->sec_per_clus,
+ GFP_NOFS, 0);
first_cl = cluster;
}
for (i = 0; i < nr_bhs; i++) {
wait_on_buffer(bhs[i]);
- if (buffer_eopnotsupp(bhs[i])) {
- clear_buffer_eopnotsupp(bhs[i]);
- err = -EOPNOTSUPP;
- } else if (!err && !buffer_uptodate(bhs[i]))
+ if (!err && !buffer_uptodate(bhs[i]))
err = -EIO;
}
return err;
lh->lh_hash = cpu_to_be32(hash);
bh->b_end_io = end_buffer_write_sync;
- if (test_bit(SDF_NOBARRIERS, &sdp->sd_flags))
- goto skip_barrier;
get_bh(bh);
- submit_bh(WRITE_BARRIER | REQ_META, bh);
- wait_on_buffer(bh);
- if (buffer_eopnotsupp(bh)) {
- clear_buffer_eopnotsupp(bh);
- set_buffer_uptodate(bh);
- fs_info(sdp, "barrier sync failed - disabling barriers\n");
- set_bit(SDF_NOBARRIERS, &sdp->sd_flags);
- lock_buffer(bh);
-skip_barrier:
- get_bh(bh);
+ if (test_bit(SDF_NOBARRIERS, &sdp->sd_flags))
submit_bh(WRITE_SYNC | REQ_META, bh);
- wait_on_buffer(bh);
- }
+ else
+ submit_bh(WRITE_FLUSH_FUA | REQ_META, bh);
+ wait_on_buffer(bh);
+
if (!buffer_uptodate(bh))
gfs2_io_error_bh(sdp, bh);
brelse(bh);
if ((start + nr_sects) != blk) {
rv = blkdev_issue_discard(bdev, start,
nr_sects, GFP_NOFS,
- BLKDEV_IFL_WAIT |
- BLKDEV_IFL_BARRIER);
+ 0);
if (rv)
goto fail;
nr_sects = 0;
}
}
if (nr_sects) {
- rv = blkdev_issue_discard(bdev, start, nr_sects, GFP_NOFS,
- BLKDEV_IFL_WAIT | BLKDEV_IFL_BARRIER);
+ rv = blkdev_issue_discard(bdev, start, nr_sects, GFP_NOFS, 0);
if (rv)
goto fail;
}
JBUFFER_TRACE(descriptor, "write commit block");
set_buffer_dirty(bh);
- if (journal->j_flags & JFS_BARRIER) {
- ret = __sync_dirty_buffer(bh, WRITE_SYNC | WRITE_BARRIER);
-
- /*
- * Is it possible for another commit to fail at roughly
- * the same time as this one? If so, we don't want to
- * trust the barrier flag in the super, but instead want
- * to remember if we sent a barrier request
- */
- if (ret == -EOPNOTSUPP) {
- char b[BDEVNAME_SIZE];
-
- printk(KERN_WARNING
- "JBD: barrier-based sync failed on %s - "
- "disabling barriers\n",
- bdevname(journal->j_dev, b));
- spin_lock(&journal->j_state_lock);
- journal->j_flags &= ~JFS_BARRIER;
- spin_unlock(&journal->j_state_lock);
-
- /* And try again, without the barrier */
- set_buffer_uptodate(bh);
- set_buffer_dirty(bh);
- ret = sync_dirty_buffer(bh);
- }
- } else {
+ if (journal->j_flags & JFS_BARRIER)
+ ret = __sync_dirty_buffer(bh, WRITE_SYNC | WRITE_FLUSH_FUA);
+ else
ret = sync_dirty_buffer(bh);
- }
put_bh(bh); /* One for getblk() */
journal_put_journal_head(descriptor);
*/
if ((journal->j_fs_dev != journal->j_dev) &&
(journal->j_flags & JBD2_BARRIER))
- blkdev_issue_flush(journal->j_fs_dev, GFP_KERNEL, NULL,
- BLKDEV_IFL_WAIT);
+ blkdev_issue_flush(journal->j_fs_dev, GFP_KERNEL, NULL);
if (!(journal->j_flags & JBD2_ABORT))
jbd2_journal_update_superblock(journal, 1);
return 0;
if (journal->j_flags & JBD2_BARRIER &&
!JBD2_HAS_INCOMPAT_FEATURE(journal,
- JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT)) {
- ret = submit_bh(WRITE_SYNC_PLUG | WRITE_BARRIER, bh);
- if (ret == -EOPNOTSUPP) {
- printk(KERN_WARNING
- "JBD2: Disabling barriers on %s, "
- "not supported by device\n", journal->j_devname);
- write_lock(&journal->j_state_lock);
- journal->j_flags &= ~JBD2_BARRIER;
- write_unlock(&journal->j_state_lock);
-
- /* And try again, without the barrier */
- lock_buffer(bh);
- set_buffer_uptodate(bh);
- clear_buffer_dirty(bh);
- ret = submit_bh(WRITE_SYNC_PLUG, bh);
- }
- } else {
+ JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT))
+ ret = submit_bh(WRITE_SYNC_PLUG | WRITE_FLUSH_FUA, bh);
+ else
ret = submit_bh(WRITE_SYNC_PLUG, bh);
- }
+
*cbh = bh;
return ret;
}
{
int ret = 0;
-retry:
clear_buffer_dirty(bh);
wait_on_buffer(bh);
- if (buffer_eopnotsupp(bh) && (journal->j_flags & JBD2_BARRIER)) {
- printk(KERN_WARNING
- "JBD2: %s: disabling barries on %s - not supported "
- "by device\n", __func__, journal->j_devname);
- write_lock(&journal->j_state_lock);
- journal->j_flags &= ~JBD2_BARRIER;
- write_unlock(&journal->j_state_lock);
-
- lock_buffer(bh);
- clear_buffer_dirty(bh);
- set_buffer_uptodate(bh);
- bh->b_end_io = journal_end_buffer_io_sync;
-
- ret = submit_bh(WRITE_SYNC_PLUG, bh);
- if (ret) {
- unlock_buffer(bh);
- return ret;
- }
- goto retry;
- }
if (unlikely(!buffer_uptodate(bh)))
ret = -EIO;
}
}
+ err = journal_finish_inode_data_buffers(journal, commit_transaction);
+ if (err) {
+ printk(KERN_WARNING
+ "JBD2: Detected IO errors while flushing file data "
+ "on %s\n", journal->j_devname);
+ if (journal->j_flags & JBD2_ABORT_ON_SYNCDATA_ERR)
+ jbd2_journal_abort(journal, err);
+ err = 0;
+ }
+
/*
* If the journal is not located on the file system device,
* then we must flush the file system device before we issue
if (commit_transaction->t_flushed_data_blocks &&
(journal->j_fs_dev != journal->j_dev) &&
(journal->j_flags & JBD2_BARRIER))
- blkdev_issue_flush(journal->j_fs_dev, GFP_KERNEL, NULL,
- BLKDEV_IFL_WAIT);
+ blkdev_issue_flush(journal->j_fs_dev, GFP_KERNEL, NULL);
/* Done it all: now write the commit record asynchronously. */
if (JBD2_HAS_INCOMPAT_FEATURE(journal,
&cbh, crc32_sum);
if (err)
__jbd2_journal_abort_hard(journal);
- if (journal->j_flags & JBD2_BARRIER)
- blkdev_issue_flush(journal->j_dev, GFP_KERNEL, NULL,
- BLKDEV_IFL_WAIT);
- }
-
- err = journal_finish_inode_data_buffers(journal, commit_transaction);
- if (err) {
- printk(KERN_WARNING
- "JBD2: Detected IO errors while flushing file data "
- "on %s\n", journal->j_devname);
- if (journal->j_flags & JBD2_ABORT_ON_SYNCDATA_ERR)
- jbd2_journal_abort(journal, err);
- err = 0;
}
/* Lo and behold: we have just managed to send a transaction to
}
if (!err && !is_journal_aborted(journal))
err = journal_wait_on_commit_record(journal, cbh);
+ if (JBD2_HAS_INCOMPAT_FEATURE(journal,
+ JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT) &&
+ journal->j_flags & JBD2_BARRIER) {
+ blkdev_issue_flush(journal->j_dev, GFP_KERNEL, NULL);
+ }
if (err)
jbd2_journal_abort(journal, err);
retry:
set_buffer_dirty(nilfs->ns_sbh[0]);
-
if (nilfs_test_opt(sbi, BARRIER)) {
err = __sync_dirty_buffer(nilfs->ns_sbh[0],
- WRITE_SYNC | WRITE_BARRIER);
- if (err == -EOPNOTSUPP) {
- nilfs_warning(sbi->s_super, __func__,
- "barrier-based sync failed. "
- "disabling barriers\n");
- nilfs_clear_opt(sbi, BARRIER);
- goto retry;
- }
+ WRITE_SYNC | WRITE_FLUSH_FUA);
} else {
err = sync_dirty_buffer(nilfs->ns_sbh[0]);
}
ret = blkdev_issue_discard(nilfs->ns_bdev,
start * sects_per_block,
nblocks * sects_per_block,
- GFP_NOFS,
- BLKDEV_IFL_WAIT |
- BLKDEV_IFL_BARRIER);
+ GFP_NOFS, 0);
if (ret < 0)
return ret;
nblocks = 0;
ret = blkdev_issue_discard(nilfs->ns_bdev,
start * sects_per_block,
nblocks * sects_per_block,
- GFP_NOFS,
- BLKDEV_IFL_WAIT | BLKDEV_IFL_BARRIER);
+ GFP_NOFS, 0);
return ret;
}
barrier_done = reiserfs_commit_for_inode(inode);
reiserfs_write_unlock(inode->i_sb);
if (barrier_done != 1 && reiserfs_barrier_flush(inode->i_sb))
- blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL,
- BLKDEV_IFL_WAIT);
+ blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL);
if (barrier_done < 0)
return barrier_done;
return (err < 0) ? -EIO : 0;
return 0;
}
-static void disable_barrier(struct super_block *s)
-{
- REISERFS_SB(s)->s_mount_opt &= ~(1 << REISERFS_BARRIER_FLUSH);
- printk("reiserfs: disabling flush barriers on %s\n",
- reiserfs_bdevname(s));
-}
-
static struct reiserfs_bitmap_node *allocate_bitmap_node(struct super_block
*sb)
{
submit_bh(WRITE, bh);
}
-static int submit_barrier_buffer(struct buffer_head *bh)
-{
- get_bh(bh);
- bh->b_end_io = reiserfs_end_ordered_io;
- clear_buffer_dirty(bh);
- if (!buffer_uptodate(bh))
- BUG();
- return submit_bh(WRITE_BARRIER, bh);
-}
-
-static void check_barrier_completion(struct super_block *s,
- struct buffer_head *bh)
-{
- if (buffer_eopnotsupp(bh)) {
- clear_buffer_eopnotsupp(bh);
- disable_barrier(s);
- set_buffer_uptodate(bh);
- set_buffer_dirty(bh);
- reiserfs_write_unlock(s);
- sync_dirty_buffer(bh);
- reiserfs_write_lock(s);
- }
-}
-
#define CHUNK_SIZE 32
struct buffer_chunk {
struct buffer_head *bh[CHUNK_SIZE];
struct buffer_head *tbh = NULL;
unsigned int trans_id = jl->j_trans_id;
struct reiserfs_journal *journal = SB_JOURNAL(s);
- int barrier = 0;
int retval = 0;
int write_len;
}
atomic_dec(&journal->j_async_throttle);
- /* We're skipping the commit if there's an error */
- if (retval || reiserfs_is_journal_aborted(journal))
- barrier = 0;
-
- /* wait on everything written so far before writing the commit
- * if we are in barrier mode, send the commit down now
- */
- barrier = reiserfs_barrier_flush(s);
- if (barrier) {
- int ret;
- lock_buffer(jl->j_commit_bh);
- ret = submit_barrier_buffer(jl->j_commit_bh);
- if (ret == -EOPNOTSUPP) {
- set_buffer_uptodate(jl->j_commit_bh);
- disable_barrier(s);
- barrier = 0;
- }
- }
for (i = 0; i < (jl->j_len + 1); i++) {
bn = SB_ONDISK_JOURNAL_1st_BLOCK(s) +
(jl->j_start + i) % SB_ONDISK_JOURNAL_SIZE(s);
BUG_ON(atomic_read(&(jl->j_commit_left)) != 1);
- if (!barrier) {
- /* If there was a write error in the journal - we can't commit
- * this transaction - it will be invalid and, if successful,
- * will just end up propagating the write error out to
- * the file system. */
- if (likely(!retval && !reiserfs_is_journal_aborted (journal))) {
- if (buffer_dirty(jl->j_commit_bh))
- BUG();
- mark_buffer_dirty(jl->j_commit_bh) ;
- reiserfs_write_unlock(s);
- sync_dirty_buffer(jl->j_commit_bh) ;
- reiserfs_write_lock(s);
- }
- } else {
+ /* If there was a write error in the journal - we can't commit
+ * this transaction - it will be invalid and, if successful,
+ * will just end up propagating the write error out to
+ * the file system. */
+ if (likely(!retval && !reiserfs_is_journal_aborted (journal))) {
+ if (buffer_dirty(jl->j_commit_bh))
+ BUG();
+ mark_buffer_dirty(jl->j_commit_bh) ;
reiserfs_write_unlock(s);
- wait_on_buffer(jl->j_commit_bh);
+ if (reiserfs_barrier_flush(s))
+ __sync_dirty_buffer(jl->j_commit_bh, WRITE_FLUSH_FUA);
+ else
+ sync_dirty_buffer(jl->j_commit_bh);
reiserfs_write_lock(s);
}
- check_barrier_completion(s, jl->j_commit_bh);
-
/* If there was a write error in the journal - we can't commit this
* transaction - it will be invalid and, if successful, will just end
* up propagating the write error out to the filesystem. */
jh->j_first_unflushed_offset = cpu_to_le32(offset);
jh->j_mount_id = cpu_to_le32(journal->j_mount_id);
- if (reiserfs_barrier_flush(sb)) {
- int ret;
- lock_buffer(journal->j_header_bh);
- ret = submit_barrier_buffer(journal->j_header_bh);
- if (ret == -EOPNOTSUPP) {
- set_buffer_uptodate(journal->j_header_bh);
- disable_barrier(sb);
- goto sync;
- }
- reiserfs_write_unlock(sb);
- wait_on_buffer(journal->j_header_bh);
- reiserfs_write_lock(sb);
- check_barrier_completion(sb, journal->j_header_bh);
- } else {
- sync:
- set_buffer_dirty(journal->j_header_bh);
- reiserfs_write_unlock(sb);
+ set_buffer_dirty(journal->j_header_bh);
+ reiserfs_write_unlock(sb);
+
+ if (reiserfs_barrier_flush(sb))
+ __sync_dirty_buffer(journal->j_header_bh, WRITE_FLUSH_FUA);
+ else
sync_dirty_buffer(journal->j_header_bh);
- reiserfs_write_lock(sb);
- }
+
+ reiserfs_write_lock(sb);
if (!buffer_uptodate(journal->j_header_bh)) {
reiserfs_warning(sb, "journal-837",
"IO error during journal replay");
xfs_buf_t *bp =
container_of(work, xfs_buf_t, b_iodone_work);
- /*
- * We can get an EOPNOTSUPP to ordered writes. Here we clear the
- * ordered flag and reissue them. Because we can't tell the higher
- * layers directly that they should not issue ordered I/O anymore, they
- * need to check if the _XFS_BARRIER_FAILED flag was set during I/O completion.
- */
- if ((bp->b_error == EOPNOTSUPP) &&
- (bp->b_flags & (XBF_ORDERED|XBF_ASYNC)) == (XBF_ORDERED|XBF_ASYNC)) {
- trace_xfs_buf_ordered_retry(bp, _RET_IP_);
- bp->b_flags &= ~XBF_ORDERED;
- bp->b_flags |= _XFS_BARRIER_FAILED;
- xfs_buf_iorequest(bp);
- } else if (bp->b_iodone)
+ if (bp->b_iodone)
(*(bp->b_iodone))(bp);
else if (bp->b_flags & XBF_ASYNC)
xfs_buf_relse(bp);
if (bp->b_flags & XBF_ORDERED) {
ASSERT(!(bp->b_flags & XBF_READ));
- rw = WRITE_BARRIER;
+ rw = WRITE_FLUSH_FUA;
} else if (bp->b_flags & XBF_LOG_BUFFER) {
ASSERT(!(bp->b_flags & XBF_READ_AHEAD));
bp->b_flags &= ~_XBF_RUN_QUEUES;
*/
#define _XBF_PAGE_LOCKED (1 << 22)
-/*
- * If we try a barrier write, but it fails we have to communicate
- * this to the upper layers. Unfortunately b_error gets overwritten
- * when the buffer is re-issued so we have to add another flag to
- * keep this information.
- */
-#define _XFS_BARRIER_FAILED (1 << 23)
-
typedef unsigned int xfs_buf_flags_t;
#define XFS_BUF_FLAGS \
{ _XBF_PAGES, "PAGES" }, \
{ _XBF_RUN_QUEUES, "RUN_QUEUES" }, \
{ _XBF_DELWRI_Q, "DELWRI_Q" }, \
- { _XBF_PAGE_LOCKED, "PAGE_LOCKED" }, \
- { _XFS_BARRIER_FAILED, "BARRIER_FAILED" }
+ { _XBF_PAGE_LOCKED, "PAGE_LOCKED" }
typedef enum {
xfs_blkdev_issue_flush(
xfs_buftarg_t *buftarg)
{
- blkdev_issue_flush(buftarg->bt_bdev, GFP_KERNEL, NULL,
- BLKDEV_IFL_WAIT);
+ blkdev_issue_flush(buftarg->bt_bdev, GFP_KERNEL, NULL);
}
STATIC void
DEFINE_BUF_EVENT(xfs_buf_lock_done);
DEFINE_BUF_EVENT(xfs_buf_cond_lock);
DEFINE_BUF_EVENT(xfs_buf_unlock);
-DEFINE_BUF_EVENT(xfs_buf_ordered_retry);
DEFINE_BUF_EVENT(xfs_buf_iowait);
DEFINE_BUF_EVENT(xfs_buf_iowait_done);
DEFINE_BUF_EVENT(xfs_buf_delwri_queue);
l = iclog->ic_log;
/*
- * If the _XFS_BARRIER_FAILED flag was set by a lower
- * layer, it means the underlying device no longer supports
- * barrier I/O. Warn loudly and turn off barriers.
- */
- if (bp->b_flags & _XFS_BARRIER_FAILED) {
- bp->b_flags &= ~_XFS_BARRIER_FAILED;
- l->l_mp->m_flags &= ~XFS_MOUNT_BARRIER;
- xfs_fs_cmn_err(CE_WARN, l->l_mp,
- "xlog_iodone: Barriers are no longer supported"
- " by device. Disabling barriers\n");
- }
-
- /*
* Race to shutdown the filesystem if we see an error.
*/
if (XFS_TEST_ERROR((XFS_BUF_GETERROR(bp)), l->l_mp,
__REQ_FAILED, /* set if the request failed */
__REQ_QUIET, /* don't worry about errors */
__REQ_PREEMPT, /* set for "ide_preempt" requests */
- __REQ_ORDERED_COLOR, /* is before or after barrier */
__REQ_ALLOCED, /* request came from our alloc pool */
__REQ_COPY_USER, /* contains copies of user pages */
__REQ_FLUSH, /* request for cache flush */
(REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER)
#define REQ_COMMON_MASK \
(REQ_WRITE | REQ_FAILFAST_MASK | REQ_HARDBARRIER | REQ_SYNC | \
- REQ_META| REQ_DISCARD | REQ_NOIDLE)
+ REQ_META | REQ_DISCARD | REQ_NOIDLE | REQ_FLUSH | REQ_FUA)
+#define REQ_CLONE_MASK REQ_COMMON_MASK
#define REQ_UNPLUG (1 << __REQ_UNPLUG)
#define REQ_RAHEAD (1 << __REQ_RAHEAD)
#define REQ_FAILED (1 << __REQ_FAILED)
#define REQ_QUIET (1 << __REQ_QUIET)
#define REQ_PREEMPT (1 << __REQ_PREEMPT)
-#define REQ_ORDERED_COLOR (1 << __REQ_ORDERED_COLOR)
#define REQ_ALLOCED (1 << __REQ_ALLOCED)
#define REQ_COPY_USER (1 << __REQ_COPY_USER)
#define REQ_FLUSH (1 << __REQ_FLUSH)
struct blk_trace *blk_trace;
#endif
/*
- * reserved for flush operations
+ * for flush operations
*/
- unsigned int ordered, next_ordered, ordseq;
- int orderr, ordcolor;
- struct request pre_flush_rq, bar_rq, post_flush_rq;
- struct request *orig_bar_rq;
+ unsigned int flush_flags;
+ unsigned int flush_seq;
+ int flush_err;
+ struct request flush_rq;
+ struct request *orig_flush_rq;
+ struct list_head pending_flushes;
struct mutex sysfs_lock;
__clear_bit(flag, &q->queue_flags);
}
-enum {
- /*
- * Hardbarrier is supported with one of the following methods.
- *
- * NONE : hardbarrier unsupported
- * DRAIN : ordering by draining is enough
- * DRAIN_FLUSH : ordering by draining w/ pre and post flushes
- * DRAIN_FUA : ordering by draining w/ pre flush and FUA write
- * TAG : ordering by tag is enough
- * TAG_FLUSH : ordering by tag w/ pre and post flushes
- * TAG_FUA : ordering by tag w/ pre flush and FUA write
- */
- QUEUE_ORDERED_BY_DRAIN = 0x01,
- QUEUE_ORDERED_BY_TAG = 0x02,
- QUEUE_ORDERED_DO_PREFLUSH = 0x10,
- QUEUE_ORDERED_DO_BAR = 0x20,
- QUEUE_ORDERED_DO_POSTFLUSH = 0x40,
- QUEUE_ORDERED_DO_FUA = 0x80,
-
- QUEUE_ORDERED_NONE = 0x00,
-
- QUEUE_ORDERED_DRAIN = QUEUE_ORDERED_BY_DRAIN |
- QUEUE_ORDERED_DO_BAR,
- QUEUE_ORDERED_DRAIN_FLUSH = QUEUE_ORDERED_DRAIN |
- QUEUE_ORDERED_DO_PREFLUSH |
- QUEUE_ORDERED_DO_POSTFLUSH,
- QUEUE_ORDERED_DRAIN_FUA = QUEUE_ORDERED_DRAIN |
- QUEUE_ORDERED_DO_PREFLUSH |
- QUEUE_ORDERED_DO_FUA,
-
- QUEUE_ORDERED_TAG = QUEUE_ORDERED_BY_TAG |
- QUEUE_ORDERED_DO_BAR,
- QUEUE_ORDERED_TAG_FLUSH = QUEUE_ORDERED_TAG |
- QUEUE_ORDERED_DO_PREFLUSH |
- QUEUE_ORDERED_DO_POSTFLUSH,
- QUEUE_ORDERED_TAG_FUA = QUEUE_ORDERED_TAG |
- QUEUE_ORDERED_DO_PREFLUSH |
- QUEUE_ORDERED_DO_FUA,
-
- /*
- * Ordered operation sequence
- */
- QUEUE_ORDSEQ_STARTED = 0x01, /* flushing in progress */
- QUEUE_ORDSEQ_DRAIN = 0x02, /* waiting for the queue to be drained */
- QUEUE_ORDSEQ_PREFLUSH = 0x04, /* pre-flushing in progress */
- QUEUE_ORDSEQ_BAR = 0x08, /* original barrier req in progress */
- QUEUE_ORDSEQ_POSTFLUSH = 0x10, /* post-flushing in progress */
- QUEUE_ORDSEQ_DONE = 0x20,
-};
-
#define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
#define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
#define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
#define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
#define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
#define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags)
-#define blk_queue_flushing(q) ((q)->ordseq)
#define blk_queue_stackable(q) \
test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
#define blk_queue_discard(q) test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags)
* it already be started by driver.
*/
#define RQ_NOMERGE_FLAGS \
- (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER)
+ (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER | \
+ REQ_FLUSH | REQ_FUA)
#define rq_mergeable(rq) \
(!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && \
(((rq)->cmd_flags & REQ_DISCARD) || \
extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
+extern void blk_queue_flush(struct request_queue *q, unsigned int flush);
extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
-extern int blk_queue_ordered(struct request_queue *, unsigned);
-extern bool blk_do_ordered(struct request_queue *, struct request **);
-extern unsigned blk_ordered_cur_seq(struct request_queue *);
-extern unsigned blk_ordered_req_seq(struct request *);
-extern bool blk_ordered_complete_seq(struct request_queue *, unsigned, int);
extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
extern void blk_dump_rq_flags(struct request *, char *);
return NULL;
return bqt->tag_index[tag];
}
-enum{
- BLKDEV_WAIT, /* wait for completion */
- BLKDEV_BARRIER, /* issue request with barrier */
- BLKDEV_SECURE, /* secure discard */
-};
-#define BLKDEV_IFL_WAIT (1 << BLKDEV_WAIT)
-#define BLKDEV_IFL_BARRIER (1 << BLKDEV_BARRIER)
-#define BLKDEV_IFL_SECURE (1 << BLKDEV_SECURE)
-extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *,
- unsigned long);
+
+#define BLKDEV_DISCARD_SECURE 0x01 /* secure discard */
+
+extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *);
extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
- sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
-static inline int sb_issue_discard(struct super_block *sb,
- sector_t block, sector_t nr_blocks)
-{
- block <<= (sb->s_blocksize_bits - 9);
- nr_blocks <<= (sb->s_blocksize_bits - 9);
- return blkdev_issue_discard(sb->s_bdev, block, nr_blocks, GFP_NOFS,
- BLKDEV_IFL_WAIT | BLKDEV_IFL_BARRIER);
+ sector_t nr_sects, gfp_t gfp_mask);
+static inline int sb_issue_discard(struct super_block *sb, sector_t block,
+ sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags)
+{
+ return blkdev_issue_discard(sb->s_bdev, block << (sb->s_blocksize_bits - 9),
+ nr_blocks << (sb->s_blocksize_bits - 9),
+ gfp_mask, flags);
}
extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm);
BH_Delay, /* Buffer is not yet allocated on disk */
BH_Boundary, /* Block is followed by a discontiguity */
BH_Write_EIO, /* I/O error on write */
- BH_Eopnotsupp, /* operation not supported (barrier) */
BH_Unwritten, /* Buffer is allocated on disk but not written */
BH_Quiet, /* Buffer Error Prinks to be quiet */
BUFFER_FNS(Delay, delay)
BUFFER_FNS(Boundary, boundary)
BUFFER_FNS(Write_EIO, write_io_error)
-BUFFER_FNS(Eopnotsupp, eopnotsupp)
BUFFER_FNS(Unwritten, unwritten)
#define bh_offset(bh) ((unsigned long)(bh)->b_data & ~PAGE_MASK)
* immediately after submission. The write equivalent
* of READ_SYNC.
* WRITE_ODIRECT_PLUG Special case write for O_DIRECT only.
- * WRITE_BARRIER Like WRITE_SYNC, but tells the block layer that all
- * previously submitted writes must be safely on storage
- * before this one is started. Also guarantees that when
- * this write is complete, it itself is also safely on
- * storage. Prevents reordering of writes on both sides
- * of this IO.
+ * WRITE_FLUSH Like WRITE_SYNC but with preceding cache flush.
+ * WRITE_FUA Like WRITE_SYNC but data is guaranteed to be on
+ * non-volatile media on completion.
+ * WRITE_FLUSH_FUA Combination of WRITE_FLUSH and FUA. The IO is preceded
+ * by a cache flush and data is guaranteed to be on
+ * non-volatile media on completion.
*
*/
#define RW_MASK REQ_WRITE
#define WRITE_SYNC (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_UNPLUG)
#define WRITE_ODIRECT_PLUG (WRITE | REQ_SYNC)
#define WRITE_META (WRITE | REQ_META)
-#define WRITE_BARRIER (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_UNPLUG | \
- REQ_HARDBARRIER)
-
-/*
- * These aren't really reads or writes, they pass down information about
- * parts of device that are now unused by the file system.
- */
-#define DISCARD_NOBARRIER (WRITE | REQ_DISCARD)
-#define DISCARD_BARRIER (WRITE | REQ_DISCARD | REQ_HARDBARRIER)
-#define DISCARD_SECURE (DISCARD_NOBARRIER | REQ_SECURE)
+#define WRITE_FLUSH (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_UNPLUG | \
+ REQ_FLUSH)
+#define WRITE_FUA (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_UNPLUG | \
+ REQ_FUA)
+#define WRITE_FLUSH_FUA (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_UNPLUG | \
+ REQ_FLUSH | REQ_FUA)
#define SEL_IN 1
#define SEL_OUT 2
static inline int scsi_populate_tag_msg(struct scsi_cmnd *cmd, char *msg)
{
struct request *req = cmd->request;
- struct scsi_device *sdev = cmd->device;
if (blk_rq_tagged(req)) {
- if (sdev->ordered_tags && req->cmd_flags & REQ_HARDBARRIER)
- *msg++ = MSG_ORDERED_TAG;
- else
- *msg++ = MSG_SIMPLE_TAG;
+ *msg++ = MSG_SIMPLE_TAG;
*msg++ = req->tag;
return 2;
}
nr_blocks = ((sector_t)se->nr_pages - 1) << (PAGE_SHIFT - 9);
if (nr_blocks) {
err = blkdev_issue_discard(si->bdev, start_block,
- nr_blocks, GFP_KERNEL, BLKDEV_IFL_WAIT);
+ nr_blocks, GFP_KERNEL, 0);
if (err)
return err;
cond_resched();
nr_blocks = (sector_t)se->nr_pages << (PAGE_SHIFT - 9);
err = blkdev_issue_discard(si->bdev, start_block,
- nr_blocks, GFP_KERNEL, BLKDEV_IFL_WAIT);
+ nr_blocks, GFP_KERNEL, 0);
if (err)
break;
start_block <<= PAGE_SHIFT - 9;
nr_blocks <<= PAGE_SHIFT - 9;
if (blkdev_issue_discard(si->bdev, start_block,
- nr_blocks, GFP_NOIO, BLKDEV_IFL_WAIT))
+ nr_blocks, GFP_NOIO, 0))
break;
}