Bradley Bolen e9a35f8b73 ubi: block: Fix locking for idr_alloc/idr_remove ... commit 7f29ae9f97 upstream. This fixes a race with idr_alloc where gd->first_minor can be set to the same value for two simultaneous calls to ubiblock_create. Each instance calls device_add_disk with the same first_minor. device_add_disk calls bdi_register_owner which generates several warnings. WARNING: CPU: 1 PID: 179 at kernel-source/fs/sysfs/dir.c:31 sysfs_warn_dup+0x68/0x88 sysfs: cannot create duplicate filename '/devices/virtual/bdi/252:2' WARNING: CPU: 1 PID: 179 at kernel-source/lib/kobject.c:240 kobject_add_internal+0x1ec/0x2f8 kobject_add_internal failed for 252:2 with -EEXIST, don't try to register things with the same name in the same directory WARNING: CPU: 1 PID: 179 at kernel-source/fs/sysfs/dir.c:31 sysfs_warn_dup+0x68/0x88 sysfs: cannot create duplicate filename '/dev/block/252:2' However, device_add_disk does not error out when bdi_register_owner returns an error. Control continues until reaching blk_register_queue. It then BUGs. kernel BUG at kernel-source/fs/sysfs/group.c:113! [<c01e26cc>] (internal_create_group) from [<c01e2950>] (sysfs_create_group+0x20/0x24) [<c01e2950>] (sysfs_create_group) from [<c00e3d38>] (blk_trace_init_sysfs+0x18/0x20) [<c00e3d38>] (blk_trace_init_sysfs) from [<c02bdfbc>] (blk_register_queue+0xd8/0x154) [<c02bdfbc>] (blk_register_queue) from [<c02cec84>] (device_add_disk+0x194/0x44c) [<c02cec84>] (device_add_disk) from [<c0436ec8>] (ubiblock_create+0x284/0x2e0) [<c0436ec8>] (ubiblock_create) from [<c0427bb8>] (vol_cdev_ioctl+0x450/0x554) [<c0427bb8>] (vol_cdev_ioctl) from [<c0189110>] (vfs_ioctl+0x30/0x44) [<c0189110>] (vfs_ioctl) from [<c01892e0>] (do_vfs_ioctl+0xa0/0x790) [<c01892e0>] (do_vfs_ioctl) from [<c0189a14>] (SyS_ioctl+0x44/0x68) [<c0189a14>] (SyS_ioctl) from [<c0010640>] (ret_fast_syscall+0x0/0x34) Locking idr_alloc/idr_remove removes the race and keeps gd->first_minor unique. Fixes: 2bf50d42f3 ("UBI: block: Dynamically allocate minor numbers") Signed-off-by: Bradley Bolen <bradleybolen@gmail.com> Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com> Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2018-02-16 20:22:57 +01:00
..
Kconfig	…
Makefile	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
attach.c	…
block.c	ubi: block: Fix locking for idr_alloc/idr_remove	2018-02-16 20:22:57 +01:00
build.c	ubi: pr_err() strings should end with newlines	2017-09-13 22:05:30 +02:00
cdev.c	…
debug.c	…
debug.h	…
eba.c	…
fastmap-wl.c	…
fastmap.c	ubi: fastmap: fix spelling mistake: "invalidiate" -> "invalidate"	2017-09-13 22:05:30 +02:00
gluebi.c	…
io.c	…
kapi.c	…
misc.c	…
ubi-media.h	UBI: Fix two typos in comments	2017-09-13 22:05:30 +02:00
ubi.h	…
upd.c	…
vmt.c	ubi: Fix race condition between ubi volume creation and udev	2018-02-16 20:22:57 +01:00
vtbl.c	…
wl.c	ubi: fastmap: Erase outdated anchor PEBs during attach	2018-02-16 20:22:57 +01:00
wl.h	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00