From: Jan Kara Date: Wed, 8 Mar 2017 16:48:34 +0000 (+0100) Subject: Revert "scsi, block: fix duplicate bdi name registration crashes" X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=c01228db4ba965986511a5b28c478bddd7e2726e;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git Revert "scsi, block: fix duplicate bdi name registration crashes" This reverts commit 0dba1314d4f81115dce711292ec7981d17231064. It causes leaking of device numbers for SCSI when SCSI registers multiple gendisks for one request_queue in succession. It can be easily reproduced using Omar's script [1] on kernel with CONFIG_DEBUG_TEST_DRIVER_REMOVE. Furthermore the protection provided by this commit is not needed anymore as the problem it was fixing got also fixed by commit 165a5e22fafb "block: Move bdi_unregister() to del_gendisk()". [1]: http://marc.info/?l=linux-block&m=148554717109098&w=2 Signed-off-by: Jan Kara Acked-by: Dan Williams Tested-by: Omar Sandoval Signed-off-by: Jens Axboe --- diff --git a/block/blk-core.c b/block/blk-core.c index 1086dac8724c..a76895c9776d 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -578,8 +578,6 @@ void blk_cleanup_queue(struct request_queue *q) q->queue_lock = &q->__queue_lock; spin_unlock_irq(lock); - 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 94f323842b52..a9c516a8b37d 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -572,20 +572,6 @@ exit: 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 @@ -626,13 +612,6 @@ 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 c7839f6c35cc..d277e8620e3e 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -3075,23 +3075,6 @@ 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; -}; - -static 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 @@ -3113,7 +3096,6 @@ static void sd_devt_release(struct disk_devt *disk_devt) 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; @@ -3139,13 +3121,9 @@ 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_devt; + goto out_free; do { if (!ida_pre_get(&sd_index_ida, GFP_KERNEL)) @@ -3161,11 +3139,6 @@ 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"); @@ -3205,12 +3178,11 @@ static int sd_probe(struct device *dev) return 0; out_free_index: - put_disk_devt(&sd_devt->disk_devt); - sd_devt = NULL; + spin_lock(&sd_index_lock); + ida_remove(&sd_index_ida, index); + spin_unlock(&sd_index_lock); out_put: put_disk(gd); - out_free_devt: - kfree(sd_devt); out_free: kfree(sdkp); out: @@ -3271,7 +3243,10 @@ static void scsi_disk_release(struct device *dev) struct scsi_disk *sdkp = to_scsi_disk(dev); struct gendisk *disk = sdkp->disk; - put_disk_devt(disk->disk_devt); + spin_lock(&sd_index_lock); + ida_remove(&sd_index_ida, sdkp->index); + spin_unlock(&sd_index_lock); + 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 796016e63c1d..5a7da607ca04 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -435,7 +435,6 @@ 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 a999d281a2f1..76f39754e7b0 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -167,13 +167,6 @@ 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, @@ -183,7 +176,6 @@ 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);