| Message ID | 148598661794.11527.10024529085859239448.stgit@dwillia2-desk3.amr.corp.intel.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
On Wed, 2017-02-01 at 14:05 -0800, Dan Williams wrote: > Warnings of the following form occur because scsi reuses a devt number > while the block layer still has it referenced as the name of the bdi Thanks! Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
On 02/01/2017 02:05 PM, Dan Williams wrote: > Warnings of the following form occur because scsi reuses a devt number > while the block layer still has it referenced as the name of the bdi > [1]: > > WARNING: CPU: 1 PID: 93 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x62/0x80 > sysfs: cannot create duplicate filename '/devices/virtual/bdi/8:192' > [..] > Call Trace: > dump_stack+0x86/0xc3 > __warn+0xcb/0xf0 > warn_slowpath_fmt+0x5f/0x80 > ? kernfs_path_from_node+0x4f/0x60 > sysfs_warn_dup+0x62/0x80 > sysfs_create_dir_ns+0x77/0x90 > kobject_add_internal+0xb2/0x350 > kobject_add+0x75/0xd0 > device_add+0x15a/0x650 > device_create_groups_vargs+0xe0/0xf0 > device_create_vargs+0x1c/0x20 > bdi_register+0x90/0x240 > ? lockdep_init_map+0x57/0x200 > bdi_register_owner+0x36/0x60 > device_add_disk+0x1bb/0x4e0 > ? __pm_runtime_use_autosuspend+0x5c/0x70 > sd_probe_async+0x10d/0x1c0 > async_run_entry_fn+0x39/0x170 > > This is a brute-force fix to pass the devt release information from > sd_probe() to the locations where we register the bdi, > device_add_disk(), and unregister the bdi, blk_cleanup_queue(). > > Thanks to Omar for the quick reproducer script [2]. This patch survives > where an unmodified kernel fails in a few seconds. What is the patch against? Doesn't seem to apply cleanly for me on master, nor the 4.11 block tree.
On Wed, Feb 1, 2017 at 2:35 PM, Jens Axboe <axboe@kernel.dk> wrote: > On 02/01/2017 02:05 PM, Dan Williams wrote: >> Warnings of the following form occur because scsi reuses a devt number >> while the block layer still has it referenced as the name of the bdi >> [1]: >> >> WARNING: CPU: 1 PID: 93 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x62/0x80 >> sysfs: cannot create duplicate filename '/devices/virtual/bdi/8:192' >> [..] >> Call Trace: >> dump_stack+0x86/0xc3 >> __warn+0xcb/0xf0 >> warn_slowpath_fmt+0x5f/0x80 >> ? kernfs_path_from_node+0x4f/0x60 >> sysfs_warn_dup+0x62/0x80 >> sysfs_create_dir_ns+0x77/0x90 >> kobject_add_internal+0xb2/0x350 >> kobject_add+0x75/0xd0 >> device_add+0x15a/0x650 >> device_create_groups_vargs+0xe0/0xf0 >> device_create_vargs+0x1c/0x20 >> bdi_register+0x90/0x240 >> ? lockdep_init_map+0x57/0x200 >> bdi_register_owner+0x36/0x60 >> device_add_disk+0x1bb/0x4e0 >> ? __pm_runtime_use_autosuspend+0x5c/0x70 >> sd_probe_async+0x10d/0x1c0 >> async_run_entry_fn+0x39/0x170 >> >> This is a brute-force fix to pass the devt release information from >> sd_probe() to the locations where we register the bdi, >> device_add_disk(), and unregister the bdi, blk_cleanup_queue(). >> >> Thanks to Omar for the quick reproducer script [2]. This patch survives >> where an unmodified kernel fails in a few seconds. > > What is the patch against? Doesn't seem to apply cleanly for me on > master, nor the 4.11 block tree. > I built it on top of Jan's bdi fixes series [1]. I can rebase to block/for-next, just let me know which patches you want to take first. [1]: http://marc.info/?l=linux-block&m=148586843819160&w=2
On 02/01/2017 02:40 PM, Dan Williams wrote: > On Wed, Feb 1, 2017 at 2:35 PM, Jens Axboe <axboe@kernel.dk> wrote: >> On 02/01/2017 02:05 PM, Dan Williams wrote: >>> Warnings of the following form occur because scsi reuses a devt number >>> while the block layer still has it referenced as the name of the bdi >>> [1]: >>> >>> WARNING: CPU: 1 PID: 93 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x62/0x80 >>> sysfs: cannot create duplicate filename '/devices/virtual/bdi/8:192' >>> [..] >>> Call Trace: >>> dump_stack+0x86/0xc3 >>> __warn+0xcb/0xf0 >>> warn_slowpath_fmt+0x5f/0x80 >>> ? kernfs_path_from_node+0x4f/0x60 >>> sysfs_warn_dup+0x62/0x80 >>> sysfs_create_dir_ns+0x77/0x90 >>> kobject_add_internal+0xb2/0x350 >>> kobject_add+0x75/0xd0 >>> device_add+0x15a/0x650 >>> device_create_groups_vargs+0xe0/0xf0 >>> device_create_vargs+0x1c/0x20 >>> bdi_register+0x90/0x240 >>> ? lockdep_init_map+0x57/0x200 >>> bdi_register_owner+0x36/0x60 >>> device_add_disk+0x1bb/0x4e0 >>> ? __pm_runtime_use_autosuspend+0x5c/0x70 >>> sd_probe_async+0x10d/0x1c0 >>> async_run_entry_fn+0x39/0x170 >>> >>> This is a brute-force fix to pass the devt release information from >>> sd_probe() to the locations where we register the bdi, >>> device_add_disk(), and unregister the bdi, blk_cleanup_queue(). >>> >>> Thanks to Omar for the quick reproducer script [2]. This patch survives >>> where an unmodified kernel fails in a few seconds. >> >> What is the patch against? Doesn't seem to apply cleanly for me on >> master, nor the 4.11 block tree. >> > > I built it on top of Jan's bdi fixes series [1]. I can rebase to > block/for-next, just let me know which patches you want to take first. > > [1]: http://marc.info/?l=linux-block&m=148586843819160&w=2 Ah, no that's fine, we'll just pull Jan's stuff in first. Makes sense.
Looks good,
Reviewed-by: Christoph Hellwig <hch@lst.de>
On 02/01/2017 03:43 PM, Jens Axboe wrote: > On 02/01/2017 02:40 PM, Dan Williams wrote: >> On Wed, Feb 1, 2017 at 2:35 PM, Jens Axboe <axboe@kernel.dk> wrote: >>> On 02/01/2017 02:05 PM, Dan Williams wrote: >>>> Warnings of the following form occur because scsi reuses a devt number >>>> while the block layer still has it referenced as the name of the bdi >>>> [1]: >>>> >>>> WARNING: CPU: 1 PID: 93 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x62/0x80 >>>> sysfs: cannot create duplicate filename '/devices/virtual/bdi/8:192' >>>> [..] >>>> Call Trace: >>>> dump_stack+0x86/0xc3 >>>> __warn+0xcb/0xf0 >>>> warn_slowpath_fmt+0x5f/0x80 >>>> ? kernfs_path_from_node+0x4f/0x60 >>>> sysfs_warn_dup+0x62/0x80 >>>> sysfs_create_dir_ns+0x77/0x90 >>>> kobject_add_internal+0xb2/0x350 >>>> kobject_add+0x75/0xd0 >>>> device_add+0x15a/0x650 >>>> device_create_groups_vargs+0xe0/0xf0 >>>> device_create_vargs+0x1c/0x20 >>>> bdi_register+0x90/0x240 >>>> ? lockdep_init_map+0x57/0x200 >>>> bdi_register_owner+0x36/0x60 >>>> device_add_disk+0x1bb/0x4e0 >>>> ? __pm_runtime_use_autosuspend+0x5c/0x70 >>>> sd_probe_async+0x10d/0x1c0 >>>> async_run_entry_fn+0x39/0x170 >>>> >>>> This is a brute-force fix to pass the devt release information from >>>> sd_probe() to the locations where we register the bdi, >>>> device_add_disk(), and unregister the bdi, blk_cleanup_queue(). >>>> >>>> Thanks to Omar for the quick reproducer script [2]. This patch survives >>>> where an unmodified kernel fails in a few seconds. >>> >>> What is the patch against? Doesn't seem to apply cleanly for me on >>> master, nor the 4.11 block tree. >>> >> >> I built it on top of Jan's bdi fixes series [1]. I can rebase to >> block/for-next, just let me know which patches you want to take first. >> >> [1]: http://marc.info/?l=linux-block&m=148586843819160&w=2 > > Ah, no that's fine, we'll just pull Jan's stuff in first. Makes sense. Both are now applied, thanks Dan.
diff --git a/block/blk-core.c b/block/blk-core.c index 84fabb51714a..0cd6b3c4b41c 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -595,6 +595,7 @@ void blk_cleanup_queue(struct request_queue *q) spin_unlock_irq(lock); bdi_unregister(q->backing_dev_info); + put_disk_devt(q->disk_devt); /* @q is and will stay empty, shutdown and put */ blk_put_queue(q); diff --git a/block/genhd.c b/block/genhd.c index d9ccd42f3675..3631cd480295 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -572,6 +572,20 @@ static void register_disk(struct device *parent, struct gendisk *disk) disk_part_iter_exit(&piter); } +void put_disk_devt(struct disk_devt *disk_devt) +{ + if (disk_devt && atomic_dec_and_test(&disk_devt->count)) + disk_devt->release(disk_devt); +} +EXPORT_SYMBOL(put_disk_devt); + +void get_disk_devt(struct disk_devt *disk_devt) +{ + if (disk_devt) + atomic_inc(&disk_devt->count); +} +EXPORT_SYMBOL(get_disk_devt); + /** * device_add_disk - add partitioning information to kernel list * @parent: parent device for the disk @@ -612,6 +626,13 @@ void device_add_disk(struct device *parent, struct gendisk *disk) disk_alloc_events(disk); + /* + * Take a reference on the devt and assign it to queue since it + * must not be reallocated while the bdi is registered + */ + disk->queue->disk_devt = disk->disk_devt; + get_disk_devt(disk->disk_devt); + /* Register BDI before referencing it from bdev */ bdi = disk->queue->backing_dev_info; bdi_register_owner(bdi, disk_to_dev(disk)); diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 0b09638fa39b..102111e730ce 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -3067,6 +3067,23 @@ static void sd_probe_async(void *data, async_cookie_t cookie) put_device(&sdkp->dev); } +struct sd_devt { + int idx; + struct disk_devt disk_devt; +}; + +void sd_devt_release(struct disk_devt *disk_devt) +{ + struct sd_devt *sd_devt = container_of(disk_devt, struct sd_devt, + disk_devt); + + spin_lock(&sd_index_lock); + ida_remove(&sd_index_ida, sd_devt->idx); + spin_unlock(&sd_index_lock); + + kfree(sd_devt); +} + /** * sd_probe - called during driver initialization and whenever a * new scsi device is attached to the system. It is called once @@ -3088,6 +3105,7 @@ static void sd_probe_async(void *data, async_cookie_t cookie) static int sd_probe(struct device *dev) { struct scsi_device *sdp = to_scsi_device(dev); + struct sd_devt *sd_devt; struct scsi_disk *sdkp; struct gendisk *gd; int index; @@ -3113,9 +3131,13 @@ static int sd_probe(struct device *dev) if (!sdkp) goto out; + sd_devt = kzalloc(sizeof(*sd_devt), GFP_KERNEL); + if (!sd_devt) + goto out_free; + gd = alloc_disk(SD_MINORS); if (!gd) - goto out_free; + goto out_free_devt; do { if (!ida_pre_get(&sd_index_ida, GFP_KERNEL)) @@ -3131,6 +3153,11 @@ static int sd_probe(struct device *dev) goto out_put; } + atomic_set(&sd_devt->disk_devt.count, 1); + sd_devt->disk_devt.release = sd_devt_release; + sd_devt->idx = index; + gd->disk_devt = &sd_devt->disk_devt; + error = sd_format_disk_name("sd", index, gd->disk_name, DISK_NAME_LEN); if (error) { sdev_printk(KERN_WARNING, sdp, "SCSI disk (sd) name length exceeded.\n"); @@ -3170,13 +3197,14 @@ static int sd_probe(struct device *dev) return 0; out_free_index: - spin_lock(&sd_index_lock); - ida_remove(&sd_index_ida, index); - spin_unlock(&sd_index_lock); + put_disk_devt(&sd_devt->disk_devt); + sd_devt = NULL; out_put: put_disk(gd); out_free: kfree(sdkp); + out_free_devt: + kfree(sd_devt); out: scsi_autopm_put_device(sdp); return error; @@ -3235,10 +3263,7 @@ static void scsi_disk_release(struct device *dev) struct scsi_disk *sdkp = to_scsi_disk(dev); struct gendisk *disk = sdkp->disk; - spin_lock(&sd_index_lock); - ida_remove(&sd_index_ida, sdkp->index); - spin_unlock(&sd_index_lock); - + put_disk_devt(disk->disk_devt); disk->private_data = NULL; put_disk(disk); put_device(&sdkp->device->sdev_gendev); diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 3c0ff78b1219..53195a4d597a 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -433,6 +433,7 @@ struct request_queue { struct delayed_work delay_work; struct backing_dev_info *backing_dev_info; + struct disk_devt *disk_devt; /* * The queue owner gets to use this for whatever they like. diff --git a/include/linux/genhd.h b/include/linux/genhd.h index 76f39754e7b0..a999d281a2f1 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -167,6 +167,13 @@ struct blk_integrity { }; #endif /* CONFIG_BLK_DEV_INTEGRITY */ +struct disk_devt { + atomic_t count; + void (*release)(struct disk_devt *disk_devt); +}; + +void put_disk_devt(struct disk_devt *disk_devt); +void get_disk_devt(struct disk_devt *disk_devt); struct gendisk { /* major, first_minor and minors are input parameters only, @@ -176,6 +183,7 @@ struct gendisk { int first_minor; int minors; /* maximum number of minors, =1 for * disks that can't be partitioned. */ + struct disk_devt *disk_devt; char disk_name[DISK_NAME_LEN]; /* name of major driver */ char *(*devnode)(struct gendisk *gd, umode_t *mode);