From 9fd097b14918875bd6f125ed699d7bbbba5893ee Mon Sep 17 00:00:00 2001 From: Tejun Heo <tj@kernel.org> Date: Thu, 21 Apr 2011 21:32:55 +0200 Subject: block: unexport DISK_EVENT_MEDIA_CHANGE for legacy/fringe drivers In-kernel disk event polling doesn't matter for legacy/fringe drivers and may lead to infinite event loop if ->check_events() implementation generates events on level condition instead of edge. Now that block layer supports suppressing exporting unlisted events, simply leaving disk->events cleared allows these drivers to keep the internal revalidation behavior intact while avoiding weird interactions with userland event handler. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Jens Axboe <jaxboe@fusionio.com> --- drivers/block/DAC960.c | 1 - drivers/block/amiflop.c | 1 - drivers/block/ataflop.c | 1 - drivers/block/floppy.c | 1 - drivers/block/paride/pcd.c | 1 - drivers/block/paride/pd.c | 1 - drivers/block/paride/pf.c | 1 - drivers/block/swim.c | 1 - drivers/block/swim3.c | 1 - drivers/block/ub.c | 1 - drivers/block/xsysace.c | 1 - drivers/cdrom/gdrom.c | 1 - drivers/cdrom/viocd.c | 1 - drivers/message/i2o/i2o_block.c | 1 - drivers/s390/char/tape_block.c | 1 - 15 files changed, 15 deletions(-) (limited to 'drivers') diff --git a/drivers/block/DAC960.c b/drivers/block/DAC960.c index 8066d086578a..e086fbbbe853 100644 --- a/drivers/block/DAC960.c +++ b/drivers/block/DAC960.c @@ -2547,7 +2547,6 @@ static bool DAC960_RegisterBlockDevice(DAC960_Controller_T *Controller) disk->major = MajorNumber; disk->first_minor = n << DAC960_MaxPartitionsBits; disk->fops = &DAC960_BlockDeviceOperations; - disk->events = DISK_EVENT_MEDIA_CHANGE; } /* Indicate the Block Device Registration completed successfully, diff --git a/drivers/block/amiflop.c b/drivers/block/amiflop.c index 456c0cc90dcf..8eba86bba599 100644 --- a/drivers/block/amiflop.c +++ b/drivers/block/amiflop.c @@ -1736,7 +1736,6 @@ static int __init fd_probe_drives(void) disk->major = FLOPPY_MAJOR; disk->first_minor = drive; disk->fops = &floppy_fops; - disk->events = DISK_EVENT_MEDIA_CHANGE; sprintf(disk->disk_name, "fd%d", drive); disk->private_data = &unit[drive]; set_capacity(disk, 880*2); diff --git a/drivers/block/ataflop.c b/drivers/block/ataflop.c index c871eae14120..ede16c64ff07 100644 --- a/drivers/block/ataflop.c +++ b/drivers/block/ataflop.c @@ -1964,7 +1964,6 @@ static int __init atari_floppy_init (void) unit[i].disk->first_minor = i; sprintf(unit[i].disk->disk_name, "fd%d", i); unit[i].disk->fops = &floppy_fops; - unit[i].disk->events = DISK_EVENT_MEDIA_CHANGE; unit[i].disk->private_data = &unit[i]; unit[i].disk->queue = blk_init_queue(do_fd_request, &ataflop_lock); diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c index 301d7a9a41a6..db8f88586c8d 100644 --- a/drivers/block/floppy.c +++ b/drivers/block/floppy.c @@ -4205,7 +4205,6 @@ static int __init floppy_init(void) disks[dr]->major = FLOPPY_MAJOR; disks[dr]->first_minor = TOMINOR(dr); disks[dr]->fops = &floppy_fops; - disks[dr]->events = DISK_EVENT_MEDIA_CHANGE; sprintf(disks[dr]->disk_name, "fd%d", dr); init_timer(&motor_off_timer[dr]); diff --git a/drivers/block/paride/pcd.c b/drivers/block/paride/pcd.c index 2f2ccf686251..8690e31d9932 100644 --- a/drivers/block/paride/pcd.c +++ b/drivers/block/paride/pcd.c @@ -320,7 +320,6 @@ static void pcd_init_units(void) disk->first_minor = unit; strcpy(disk->disk_name, cd->name); /* umm... */ disk->fops = &pcd_bdops; - disk->events = DISK_EVENT_MEDIA_CHANGE; } } diff --git a/drivers/block/paride/pd.c b/drivers/block/paride/pd.c index 21dfdb776869..869e7676d46f 100644 --- a/drivers/block/paride/pd.c +++ b/drivers/block/paride/pd.c @@ -837,7 +837,6 @@ static void pd_probe_drive(struct pd_unit *disk) p->fops = &pd_fops; p->major = major; p->first_minor = (disk - pd) << PD_BITS; - p->events = DISK_EVENT_MEDIA_CHANGE; disk->gd = p; p->private_data = disk; p->queue = pd_queue; diff --git a/drivers/block/paride/pf.c b/drivers/block/paride/pf.c index 7adeb1edbf43..f21b520ef419 100644 --- a/drivers/block/paride/pf.c +++ b/drivers/block/paride/pf.c @@ -294,7 +294,6 @@ static void __init pf_init_units(void) disk->first_minor = unit; strcpy(disk->disk_name, pf->name); disk->fops = &pf_fops; - disk->events = DISK_EVENT_MEDIA_CHANGE; if (!(*drives[unit])[D_PRT]) pf_drive_count++; } diff --git a/drivers/block/swim.c b/drivers/block/swim.c index 24a482f2fbd6..fd5adcd55944 100644 --- a/drivers/block/swim.c +++ b/drivers/block/swim.c @@ -858,7 +858,6 @@ static int __devinit swim_floppy_init(struct swim_priv *swd) swd->unit[drive].disk->first_minor = drive; sprintf(swd->unit[drive].disk->disk_name, "fd%d", drive); swd->unit[drive].disk->fops = &floppy_fops; - swd->unit[drive].disk->events = DISK_EVENT_MEDIA_CHANGE; swd->unit[drive].disk->private_data = &swd->unit[drive]; swd->unit[drive].disk->queue = swd->queue; set_capacity(swd->unit[drive].disk, 2880); diff --git a/drivers/block/swim3.c b/drivers/block/swim3.c index 4c10f56facbf..773bfa792777 100644 --- a/drivers/block/swim3.c +++ b/drivers/block/swim3.c @@ -1163,7 +1163,6 @@ static int __devinit swim3_attach(struct macio_dev *mdev, const struct of_device disk->major = FLOPPY_MAJOR; disk->first_minor = i; disk->fops = &floppy_fops; - disk->events = DISK_EVENT_MEDIA_CHANGE; disk->private_data = &floppy_states[i]; disk->queue = swim3_queue; disk->flags |= GENHD_FL_REMOVABLE; diff --git a/drivers/block/ub.c b/drivers/block/ub.c index 68b9430c7cfe..0e376d46bdd1 100644 --- a/drivers/block/ub.c +++ b/drivers/block/ub.c @@ -2334,7 +2334,6 @@ static int ub_probe_lun(struct ub_dev *sc, int lnum) disk->major = UB_MAJOR; disk->first_minor = lun->id * UB_PARTS_PER_LUN; disk->fops = &ub_bd_fops; - disk->events = DISK_EVENT_MEDIA_CHANGE; disk->private_data = lun; disk->driverfs_dev = &sc->intf->dev; diff --git a/drivers/block/xsysace.c b/drivers/block/xsysace.c index 645ff765cd12..6c7fd7db6dff 100644 --- a/drivers/block/xsysace.c +++ b/drivers/block/xsysace.c @@ -1005,7 +1005,6 @@ static int __devinit ace_setup(struct ace_device *ace) ace->gd->major = ace_major; ace->gd->first_minor = ace->id * ACE_NUM_MINORS; ace->gd->fops = &ace_fops; - ace->gd->events = DISK_EVENT_MEDIA_CHANGE; ace->gd->queue = ace->queue; ace->gd->private_data = ace; snprintf(ace->gd->disk_name, 32, "xs%c", ace->id + 'a'); diff --git a/drivers/cdrom/gdrom.c b/drivers/cdrom/gdrom.c index b2b034fea34e..3ceaf006e7f0 100644 --- a/drivers/cdrom/gdrom.c +++ b/drivers/cdrom/gdrom.c @@ -803,7 +803,6 @@ static int __devinit probe_gdrom(struct platform_device *devptr) goto probe_fail_cdrom_register; } gd.disk->fops = &gdrom_bdops; - gd.disk->events = DISK_EVENT_MEDIA_CHANGE; /* latch on to the interrupt */ err = gdrom_set_interrupt_handlers(); if (err) diff --git a/drivers/cdrom/viocd.c b/drivers/cdrom/viocd.c index 4e874c5fa605..e427fbe45999 100644 --- a/drivers/cdrom/viocd.c +++ b/drivers/cdrom/viocd.c @@ -626,7 +626,6 @@ static int viocd_probe(struct vio_dev *vdev, const struct vio_device_id *id) gendisk->queue = q; gendisk->fops = &viocd_fops; gendisk->flags = GENHD_FL_CD|GENHD_FL_REMOVABLE; - gendisk->events = DISK_EVENT_MEDIA_CHANGE; set_capacity(gendisk, 0); gendisk->private_data = d; d->viocd_disk = gendisk; diff --git a/drivers/message/i2o/i2o_block.c b/drivers/message/i2o/i2o_block.c index 643ad52e3ca2..4796bbf0ae4e 100644 --- a/drivers/message/i2o/i2o_block.c +++ b/drivers/message/i2o/i2o_block.c @@ -1000,7 +1000,6 @@ static struct i2o_block_device *i2o_block_device_alloc(void) gd->major = I2O_MAJOR; gd->queue = queue; gd->fops = &i2o_block_fops; - gd->events = DISK_EVENT_MEDIA_CHANGE; gd->private_data = dev; dev->gd = gd; diff --git a/drivers/s390/char/tape_block.c b/drivers/s390/char/tape_block.c index 83cea9a55e2f..1b3924c2fffd 100644 --- a/drivers/s390/char/tape_block.c +++ b/drivers/s390/char/tape_block.c @@ -236,7 +236,6 @@ tapeblock_setup_device(struct tape_device * device) disk->major = tapeblock_major; disk->first_minor = device->first_minor; disk->fops = &tapeblock_fops; - disk->events = DISK_EVENT_MEDIA_CHANGE; disk->private_data = tape_get_device(device); disk->queue = blkdat->request_queue; set_capacity(disk, 0); -- cgit v1.2.3 From bf2253a6f00e8fea5b026e471e9f0d0a1b3621f2 Mon Sep 17 00:00:00 2001 From: Tejun Heo <tj@kernel.org> Date: Fri, 29 Apr 2011 10:15:14 +0200 Subject: cdrom: always check_disk_change() on open cdrom_open() called check_disk_change() after the rest of open path succeeded which leads to the following bizarre behavior. * After media change, if the device opened without O_NONBLOCK, open_for_data() naturally fails with -ENOMEDIA and check_disk_change() is never called. The media is known to be gone and the open failure makes it obvious to the userland but device invalidation never happens. * But if the device is opened with O_NONBLOCK, all the checks are bypassed and cdrom_open() doesn't notice that the media is not there and check_disk_change() is called and invalidation happens. There's nothing to be gained by avoiding calling check_disk_change() on open failure. Common cases end up calling check_disk_change() anyway. All we get is inconsistent behavior. Fix it by moving check_disk_change() invocation to the top of cdrom_open() so that it always gets called regardless of how the rest of open proceeds. Stable: 2.6.38 Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Amit Shah <amit.shah@redhat.com> Tested-by: Amit Shah <amit.shah@redhat.com> Cc: stable@kernel.org Signed-off-by: Jens Axboe <jaxboe@fusionio.com> --- drivers/cdrom/cdrom.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'drivers') diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c index 514dd8efaf73..75fb965b8f72 100644 --- a/drivers/cdrom/cdrom.c +++ b/drivers/cdrom/cdrom.c @@ -986,6 +986,9 @@ int cdrom_open(struct cdrom_device_info *cdi, struct block_device *bdev, fmode_t cdinfo(CD_OPEN, "entering cdrom_open\n"); + /* open is event synchronization point, check events first */ + check_disk_change(bdev); + /* if this was a O_NONBLOCK open and we should honor the flags, * do a quick open without drive/disc integrity checks. */ cdi->use_count++; @@ -1012,9 +1015,6 @@ int cdrom_open(struct cdrom_device_info *cdi, struct block_device *bdev, fmode_t cdinfo(CD_OPEN, "Use count for \"/dev/%s\" now %d\n", cdi->name, cdi->use_count); - /* Do this on open. Don't wait for mount, because they might - not be mounting, but opening with O_NONBLOCK */ - check_disk_change(bdev); return 0; err_release: if (CDROM_CAN(CDC_LOCK) && cdi->options & CDO_LOCK) { -- cgit v1.2.3 From 9937a5e2f32892db0dbeefc2b3bc74b3ae3ea9c7 Mon Sep 17 00:00:00 2001 From: Jens Axboe <jaxboe@fusionio.com> Date: Tue, 17 May 2011 11:04:44 +0200 Subject: scsi: remove performance regression due to async queue run Commit c21e6beb removed our queue request_fn re-enter protection, and defaulted to always running the queues from kblockd to be safe. This was a known potential slow down, but should be safe. Unfortunately this is causing big performance regressions for some, so we need to improve this logic. Looking into the details of the re-enter, the real issue is on requeue of requests. Requeue of requests upon seeing a BUSY condition from the device ends up re-running the queue, causing traces like this: scsi_request_fn() scsi_dispatch_cmd() scsi_queue_insert() __scsi_queue_insert() scsi_run_queue() scsi_request_fn() ... potentially causing the issue we want to avoid. So special case the requeue re-run of the queue, but improve it to offload the entire run of local queue and starved queue from a single workqueue callback. This is a lot better than potentially kicking off a workqueue run for each device seen. This also fixes the issue of the local device going into recursion, since the above mentioned commit never moved that queue run out of line. Signed-off-by: Jens Axboe <jaxboe@fusionio.com> --- drivers/scsi/scsi_lib.c | 20 ++++++++++++++++---- drivers/scsi/scsi_scan.c | 2 ++ include/scsi/scsi_device.h | 1 + 3 files changed, 19 insertions(+), 4 deletions(-) (limited to 'drivers') diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index e9901b8f8443..01e4e51c4b68 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -74,8 +74,6 @@ struct kmem_cache *scsi_sdb_cache; */ #define SCSI_QUEUE_DELAY 3 -static void scsi_run_queue(struct request_queue *q); - /* * Function: scsi_unprep_request() * @@ -161,7 +159,7 @@ static int __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, int unbusy) blk_requeue_request(q, cmd->request); spin_unlock_irqrestore(q->queue_lock, flags); - scsi_run_queue(q); + kblockd_schedule_work(q, &device->requeue_work); return 0; } @@ -433,7 +431,11 @@ static void scsi_run_queue(struct request_queue *q) continue; } - blk_run_queue_async(sdev->request_queue); + spin_unlock(shost->host_lock); + spin_lock(sdev->request_queue->queue_lock); + __blk_run_queue(sdev->request_queue); + spin_unlock(sdev->request_queue->queue_lock); + spin_lock(shost->host_lock); } /* put any unprocessed entries back */ list_splice(&starved_list, &shost->starved_list); @@ -442,6 +444,16 @@ static void scsi_run_queue(struct request_queue *q) blk_run_queue(q); } +void scsi_requeue_run_queue(struct work_struct *work) +{ + struct scsi_device *sdev; + struct request_queue *q; + + sdev = container_of(work, struct scsi_device, requeue_work); + q = sdev->request_queue; + scsi_run_queue(q); +} + /* * Function: scsi_requeue_command() * diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c index 087821fac8fe..58584dc0724a 100644 --- a/drivers/scsi/scsi_scan.c +++ b/drivers/scsi/scsi_scan.c @@ -242,6 +242,7 @@ static struct scsi_device *scsi_alloc_sdev(struct scsi_target *starget, int display_failure_msg = 1, ret; struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); extern void scsi_evt_thread(struct work_struct *work); + extern void scsi_requeue_run_queue(struct work_struct *work); sdev = kzalloc(sizeof(*sdev) + shost->transportt->device_size, GFP_ATOMIC); @@ -264,6 +265,7 @@ static struct scsi_device *scsi_alloc_sdev(struct scsi_target *starget, INIT_LIST_HEAD(&sdev->event_list); spin_lock_init(&sdev->list_lock); INIT_WORK(&sdev->event_work, scsi_evt_thread); + INIT_WORK(&sdev->requeue_work, scsi_requeue_run_queue); sdev->sdev_gendev.parent = get_device(&starget->dev); sdev->sdev_target = starget; diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h index 2d3ec5094685..dd82e02ddde3 100644 --- a/include/scsi/scsi_device.h +++ b/include/scsi/scsi_device.h @@ -169,6 +169,7 @@ struct scsi_device { sdev_dev; struct execute_work ew; /* used to get process context on put */ + struct work_struct requeue_work; struct scsi_dh_data *scsi_dh_data; enum scsi_device_state sdev_state; -- cgit v1.2.3