UBI: attaching mtd1 to ubi0
UBI: scanning is finished
UBI error: init_volumes: not enough PEBs, required 706, available 686
UBI error: ubi_wl_init: no enough physical eraseblocks (-20, need 1)
UBI error: ubi_attach_mtd_dev: failed to attach mtd1, error -12 <= NOT ENOMEM
UBI error: ubi_init: cannot attach mtd1

If available PEBs are not enough when initializing volumes, return -ENOSPC
directly. If available PEBs are not enough when initializing WL, return
-ENOSPC instead of -ENOMEM.

Cc: stable@vger.kernel.org
Signed-off-by: NSheng Yong <shengyong1@huawei.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>
Reviewed-by: NDavid Gstir <david@sigma-star.at>

Make sure that data_size is less than LEB size.
Otherwise a handcrafted UBI image is able to trigger
an out of bounds memory access in ubi_compare_lebs().

Cc: stable@vger.kernel.org
Signed-off-by: NRichard Weinberger <richard@nod.at>
Reviewed-by: NDavid Gstir <david@sigma-star.at>

Signed-off-by: NSheng Yong <shengyong1@huawei.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>

This patch cleans up the manual device_create_file() or
class_create_file() calls by replacing with static attribute groups.
It simplifies the code and also avoids the possible races between the
device/class registration and sysfs creations.

For the simplification, also make ubi_class a static instance with
initializers, too.

Amend a bit by Hujianyang.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>
Tested-by: NSheng Yong <shengyong1@huawei.com>
Signed-off-by: Nhujianyang <hujianyang@huawei.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>

Signed-off-by: NSheng Yong <shengyong1@huawei.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>

During fastmap attaching, check if a volume already exists when adding
the volume to volume tree. NOTE that the issue cannot happen, only if
the on-flash fastmap data is modified.
Signed-off-by: NSheng Yong <shengyong1@huawei.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>

`vol' is a newly allocated value by kzalloc. Initialize it by assignment
instead of `+='.
Signed-off-by: NSheng Yong <shengyong1@huawei.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>

s/fmpl1/fmpl
s/fmpl2/fmpl_wl

Add "WL" to the error message when wrong WL pool magic number is detected.
Signed-off-by: NSheng Yong <shengyong1@huawei.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>

Signed-off-by: NSheng Yong <shengyong1@huawei.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>

Signed-off-by: NSheng Yong <shengyong1@huawei.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>

This patch makes ubiblock devices have minor numbers beginning from
0, allocated dynamically independently of the ubi device/volume
number. This property becomes useful because, on 32-bit architectures
with LFS turned off in a userspace program, device minor numbers
over 8 bits cause stat to return -EOVERFLOW. If the device number is
high (>1) due to multiple MTD partitions, such an overflow will occur.
While enabling LFS is clearly a nicer solution, it's often difficult
to turn on in practice globally as many widely distributed packages
don't work with LFS on.

Other storage systems have their own workarounds, with SCSI making
multiple device majors and MMC having a config option for the number
of partitions per device. A completely dynamic minor numbering is
simpler than these. It is unlikely that anyone is depending on a
static minor number since the major is dynamic anyway. In addition,
ubiblock is still relatively new, so now is the time to make such
changes.
Signed-off-by: NDan Ehrenberg <dehrenberg@chromium.org>
Acked-by: NEzequiel Garcia <ezequiel@vanguardiasur.com.ar>
Signed-off-by: NRichard Weinberger <richard@nod.at>

Most code already uses consts for the struct kernel_param_ops,
sweep the kernel for the last offending stragglers. Other than
include/linux/moduleparam.h and kernel/params.c all other changes
were generated with the following Coccinelle SmPL patch. Merge
conflicts between trees can be handled with Coccinelle.

In the future git could get Coccinelle merge support to deal with
patch --> fail --> grammar --> Coccinelle --> new patch conflicts
automatically for us on patches where the grammar is available and
the patch is of high confidence. Consider this a feature request.

Test compiled on x86_64 against:

	* allnoconfig
	* allmodconfig
	* allyesconfig

@ const_found @
identifier ops;
@@

const struct kernel_param_ops ops = {
};

@ const_not_found depends on !const_found @
identifier ops;
@@

-struct kernel_param_ops ops = {
+const struct kernel_param_ops ops = {
};

Generated-by: Coccinelle SmPL
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Junio C Hamano <gitster@pobox.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: cocci@systeme.lip6.fr
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NLuis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Block drivers are responsible for calling flush_dcache_page() on each
BIO request. This operation keeps the I$ coherent with the D$ on
architectures that don't have hardware coherency support. Without this
flush, random crashes are seen when executing user programs from an ext4
filesystem backed by a ubiblock device.

This patch is based on the change implemented in commit 2d4dc890
("block: add helpers to run flush_dcache_page() against a bio and a
request's pages").

Fixes: 9d54c8a3 ("UBI: R/O block driver on top of UBI volumes")
Signed-off-by: NKevin Cernekee <cernekee@chromium.org>
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@imgtec.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>

Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Emulate random power cuts by switching device to ro after a number of
writes to allow simple power cut testing with nand-sim.

Maximum and minimum number of successful writes before power cut and
what kind of writes (EC header, VID header or none) to interrupt
configurable via debugfs.
Signed-off-by: NDavid Oberhollenzer <david.oberhollenzer@sigma-star.at>
Signed-off-by: NRichard Weinberger <richard@nod.at>

If we encounter an uncorrectable ECC error while scanning for the fastmap
UBI must not fail hard. Instead fall back to scanning mode.
Reported-by: NAlexander Block <Alexander.Block@continental-corporation.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>

This function was added to fastmap in a very early stage
to have paranoid assertions.
With the current fastmap implementation this assert will never
trigger as fastmap PEBs are not seen by the WL sub-system.
Remove it to save us some CPU cycles.
Signed-off-by: NRichard Weinberger <richard@nod.at>

Another checkpatch complaint:
WARNING: Missing a blank line after declarations
Signed-off-by: NRichard Weinberger <richard@nod.at>

checkpatch.pl complains:
WARNING: else is not generally useful after a break or return
Signed-off-by: NRichard Weinberger <richard@nod.at>

...and kill another #ifdef.
Signed-off-by: NRichard Weinberger <richard@nod.at>

...and kill another #ifdef in wl.c. :-)
Signed-off-by: NRichard Weinberger <richard@nod.at>

Use the new WL accessor functions in fastmap.
Signed-off-by: NRichard Weinberger <richard@nod.at>

Fastmap need access to various WL data structures as
fastmap tightly depends on WL.
To make the access less invasive add accessor functions.
Signed-off-by: NRichard Weinberger <richard@nod.at>

Fastmap is tightly connected to the WL sub-system, many fastmap-specific
functionslive in wl.c.
To get rid of most #ifdefs in wl.c move this functions into a new file
and include it into wl.c
Signed-off-by: NRichard Weinberger <richard@nod.at>

If fm_debug is set fastmap debugging is enabled by default.
This is useful if one wants to debug fastmap on an UBI device
with serves the rootfs.
The the UBI attach mechanism runs long before debugfs can be mounted
and chk_fastmap set.
Signed-off-by: NRichard Weinberger <richard@nod.at>

...instead of generic self checking.
Signed-off-by: NRichard Weinberger <richard@nod.at>

This self check allows Fastmap to detect absent PEBs while
writing a new fastmap to the MTD device.
It will help to find implementation issues in Fastmap.
Signed-off-by: NRichard Weinberger <richard@nod.at>

In some error paths the WL sub-system gives up on a PEB
and frees it's ubi_wl_entry struct but does not set
the entry in ubi->lookuptbl to NULL.
Fastmap can stumble over such a stale pointer as it uses
ubi->lookuptbl to find all PEBs.

Fix this by introducing a new helper function which free()s
a WL entry and removes the reference from the lookup table.
Signed-off-by: NRichard Weinberger <richard@nod.at>

Don't update the fastmap upon detach if fastmap checking is enabled.
This is poor men's power cut testing feature. :-)
Signed-off-by: NRichard Weinberger <richard@nod.at>

Using this debugfs knob fastmap self checks can be controlled.
Signed-off-by: NRichard Weinberger <richard@nod.at>
Reviewed-by: NTanya Brokhman <tlinder@codeaurora.org>

If UBI is unable to write the fastmap to the device
we have make sure that upon next attach UBI will fall
back to scanning mode.
In case we cannot ensure that they only thing we can do
is falling back to read-only mode.

The current error handling code is not powercut proof.
It could happen that a powercut while invalidating would
lead to a state where an too old fastmap could be used upon
attach.
This patch addresses the issue by writing a fake fastmap
super block to a fresh PEB instead of reerasing the existing one.
The fake fastmap super block will UBI case to do a full scan.
Signed-off-by: NRichard Weinberger <richard@nod.at>

The current code assumes that each fastmap has the same amount of PEBs.
So far this is true but will change soon.
Signed-off-by: NRichard Weinberger <richard@nod.at>

a) Rename ubi->fm_sem to ubi->fm_eba_sem as this semaphore
protects EBA changes.
b) Turn ubi->fm_mutex into a rw semaphore. It will still serialize
fastmap writes but also ensures that ubi_wl_put_peb() is not
interrupted by a fastmap write. We use a rw semaphore to allow
ubi_wl_put_peb() still to be executed in parallel if no fastmap
write is happening.
Signed-off-by: NRichard Weinberger <richard@nod.at>

If we set it for dynamic ones we might confuse various self checks.
Signed-off-by: NRichard Weinberger <richard@nod.at>

ubi_wl_get_peb() returns a fresh PEB which can be used by
user of UBI. Due to the pool logic fastmap will correctly
map this PEB upon attach time because it will be scanned.

If a new fastmap is written (due to heavy parallel io)
while the before the fresh PEB is assigned to the EBA table
it will not be scanned as it is no longer in the pool.
So, the race window exists between ubi_wl_get_peb()
and the EBA table assignment.
We have to make sure that no new fastmap can be written
while that.

To ensure that ubi_wl_get_peb() will grab ubi->fm_sem in read mode
and the user of ubi_wl_get_peb() has to release it after the PEB
got assigned.
Signed-off-by: NRichard Weinberger <richard@nod.at>

If a LEB is unmapped we have to decrement leb_count as well.
Signed-off-by: NRichard Weinberger <richard@nod.at>

Don't use a fixed size for the WL pool.
Make it instead 50% of the user pool.
We don't make it 100% as it is not as heavily used as the user pool.
Signed-off-by: NRichard Weinberger <richard@nod.at>

We have to switch to ro mode to guarantee that upon next UBI attach
all data is consistent.
Signed-off-by: NRichard Weinberger <richard@nod.at>

This logic is in vain as we treat protected PEBs also as used, so this
case must not happen.
If a PEB is found which is in the EBA table but not known as used
has to be issued as fatal error.
Signed-off-by: NRichard Weinberger <richard@nod.at>

It is legal to have PEBs left in the used list.
This can happen if UBI copies a PEB and a powercut happens
between writing a new fastmap and adding this PEB into the EBA table.
In this case the old PEB will be used.
Signed-off-by: NRichard Weinberger <richard@nod.at>