From 0dba1314d4f81115dce711292ec7981d17231064 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Wed, 1 Feb 2017 14:05:23 -0800 Subject: scsi, block: fix duplicate bdi name registration crashes 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. [1]: https://marc.info/?l=linux-scsi&m=147116857810716&w=4 [2]: http://marc.info/?l=linux-block&m=148554717109098&w=2 Cc: James Bottomley Cc: Bart Van Assche Cc: "Martin K. Petersen" Cc: Jan Kara Reported-by: Omar Sandoval Tested-by: Omar Sandoval Signed-off-by: Dan Williams Reviewed-by: Christoph Hellwig Reviewed-by: Bart Van Assche Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 1 + include/linux/genhd.h | 8 ++++++++ 2 files changed, 9 insertions(+) (limited to 'include/linux') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index b31137e2afd0..f84fbe55d3b3 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); -- cgit v1.2.3-59-g8ed1b