WSL2-Linux-Kernel/drivers/mtd
Sebastian Siewior 9cd9a21ce0 ubi/upd: Always flush after prepared for an update
In commit 6afaf8a484 ("UBI: flush wl before clearing update marker") I
managed to trigger and fix a similar bug. Now here is another version of
which I assumed it wouldn't matter back then but it turns out UBI has a
check for it and will error out like this:

|ubi0 warning: validate_vid_hdr: inconsistent used_ebs
|ubi0 error: validate_vid_hdr: inconsistent VID header at PEB 592

All you need to trigger this is? "ubiupdatevol /dev/ubi0_0 file" + a
powercut in the middle of the operation.
ubi_start_update() sets the update-marker and puts all EBs on the erase
list. After that userland can proceed to write new data while the old EB
aren't erased completely. A powercut at this point is usually not that
much of a tragedy. UBI won't give read access to the static volume
because it has the update marker. It will most likely set the corrupted
flag because it misses some EBs.
So we are all good. Unless the size of the image that has been written
differs from the old image in the magnitude of at least one EB. In that
case UBI will find two different values for `used_ebs' and refuse to
attach the image with the error message mentioned above.

So in order not to get in the situation, the patch will ensure that we
wait until everything is removed before it tries to write any data.
The alternative would be to detect such a case and remove all EBs at the
attached time after we processed the volume-table and see the
update-marker set. The patch looks bigger and I doubt it is worth it
since usually the write() will wait from time to time for a new EB since
usually there not that many spare EB that can be used.

Cc: stable@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Richard Weinberger <richard@nod.at>
2017-03-30 09:27:11 +02:00
..
chips mtd: cfi_cmdset_0020: Deinline do_write_buffer, save 5316 bytes 2016-07-09 18:53:33 -07:00
devices Merge branch 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm 2017-02-28 11:50:53 -08:00
lpddr mtd: lpddr: show parent device in sysfs 2015-10-13 09:21:17 -07:00
maps mtd: physmap_of: fixup gemini/versatile dependencies 2017-02-10 09:53:41 -08:00
nand sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task_stack.h> 2017-03-02 08:42:36 +01:00
onenand mtd: silence some uninitialized variable warnings 2016-07-09 18:14:39 -07:00
spi-nor scripts/spelling.txt: add "disble(d)" pattern and fix typo instances 2017-03-09 17:01:09 -08:00
tests sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h> 2017-03-02 08:42:32 +01:00
ubi ubi/upd: Always flush after prepared for an update 2017-03-30 09:27:11 +02:00
Kconfig mtd: bcm63xxpart: Remove dependency on mach-bcm63xx 2016-02-12 10:27:48 -08:00
Makefile mtd: spi-nor: shorten Kconfig naming 2014-04-14 11:23:01 -07:00
afs.c mtd: partitions: make parsers return 'const' partition arrays 2015-12-09 10:21:57 -08:00
ar7part.c mtd: partitions: make parsers return 'const' partition arrays 2015-12-09 10:21:57 -08:00
bcm47xxpart.c mtd: bcm47xxpart: support layouts with multiple TRX partitions 2017-02-09 18:59:45 -08:00
bcm63xxpart.c mtd: bcm63xxpart: give width specifier an 'int', not 'size_t' 2016-03-07 13:13:58 -08:00
cmdlinepart.c mtd: partitions: make parsers return 'const' partition arrays 2015-12-09 10:21:57 -08:00
ftl.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
inftlcore.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
inftlmount.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
mtd_blkdevs.c block: fold cmd_type into the REQ_OP_ space 2017-01-31 14:00:44 -07:00
mtdblock.c mtd: mtdblock: remove the needless mtdblks_lock 2015-01-07 12:51:56 -08:00
mtdblock_ro.c mtd: Move major number definitions to major.h 2013-11-06 23:32:59 -08:00
mtdchar.c mtd: Fix typo: "occured" -> "occurred" 2017-02-08 14:24:57 -08:00
mtdconcat.c mtd: create an mtd_ooblayout_ops struct to ease ECC layout definition 2016-04-19 22:05:55 +02:00
mtdcore.c mtd: fix typos in ooblayout comment blocks 2017-02-08 13:32:08 -08:00
mtdcore.h mtd: partitions: support a cleanup callback for parsers 2015-12-09 14:57:44 -08:00
mtdoops.c mtdoops: don't erase flash at each boot 2012-11-15 15:37:51 +02:00
mtdpart.c mtd: Add partition device node to mtd partition devices 2017-02-09 19:19:25 -08:00
mtdsuper.c mtd: Move major number definitions to major.h 2013-11-06 23:32:59 -08:00
mtdswap.c mtd: mtdswap: fix spelling mistake "erassure" -> "erasure" 2016-11-22 11:43:52 -08:00
nftlcore.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
nftlmount.c mtd: nftl: reorganize operations in condition check 2015-01-09 15:26:29 -08:00
ofpart.c mtd: Add partition device node to mtd partition devices 2017-02-09 19:19:25 -08:00
redboot.c mtd: partitions: make parsers return 'const' partition arrays 2015-12-09 10:21:57 -08:00
rfd_ftl.c mtd: remove some duplicative checks 2014-03-10 22:42:25 -07:00
sm_ftl.c treewide: Fix typos in printk 2016-04-18 11:23:24 +02:00
sm_ftl.h
ssfdc.c mtd: Replace if and BUG with BUG_ON 2016-07-09 18:48:54 -07:00