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Revert "scsi, block: fix duplicate bdi name registration crashes"

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This reverts commit 0dba1314d4. 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 165a5e22fa
"block: Move bdi_unregister() to del_gendisk()".

[1]: http://marc.info/?l=linux-block&m=148554717109098&w=2

Signed-off-by: Jan Kara <jack@suse.cz>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
This commit is contained in:
Jan Kara 2017-03-08 17:48:34 +01:00 committed by Jens Axboe
parent 90f16fddcc
commit c01228db4b
5 changed files with 8 additions and 65 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
block/blk-core.c
View File

@ -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);
}

21
block/genhd.c
View File

@ -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));

41
drivers/scsi/sd.c
View File

@ -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);

1
include/linux/blkdev.h
View File

@ -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.

8
include/linux/genhd.h
View File

@ -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);