This is part of the process of hiding UBI EBA's internal to other part of
the UBI implementation, so that we can add new information to the EBA
table without having to patch different places in the UBI code.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>

ubi_leb_valid() is here to replace the
lnum < 0 || lnum >= vol->reserved_pebs checks.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>

ubi_eba_write_leb(), ubi_eba_write_leb_st() and
ubi_eba_atomic_leb_change() are using a convoluted retry/exit path.
Add the try_write_vid_and_data() function to simplify the retry logic
and make sure we have a single exit path instead of manually releasing
the resources in each error path.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>

recover_peb() is using a convoluted retry/exit path. Add try_recover_peb()
to simplify the retry logic and make sure we have a single exit path
instead of manually releasing the resource in each error path.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>

Even if it works fine with those global variables, attaching the
temporary ech and vidh objects used during UBI scan to the
ubi_attach_info object sounds like a more future-proof option.

For example, attaching several UBI devices in parallel is prevented by
this use of global variable. And also because global variables should
be avoided in general.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>

This not only hides the aeb allocation internals (which is always good in
case we ever want to change the allocation system), but also helps us
factorize the initialization of some common fields (ec and pnum).
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>

ubi_io_{read,write}_data() are wrappers around ubi_io_{read/write}() that
are used to read/write eraseblock payload data, which is exactly what
fastmap does when calling ubi_io_{read,write}().
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>

Use the ubi_rb_for_each_entry() macro instead of open-coding it.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>

Those functions are pretty much doing the same thing, except
ubi_remove_av() is putting the aeb elements attached to the volume into
the ai->erase list and the destroy_av() is freeing them.

Rework destroy_av() to handle both cases.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>

Volume creation/search code is duplicated in a few places (fastmap and
non fastmap code). Create some helpers to factorize the code.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>

vol->usable_size is already set to ubi->leb_size - vol->data_pad. Use
vol->usable_size instead of recalculating it.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>

scan_pool() does not mark the PEB for scrubing when bitflips are
detected in the EC header of a free PEB (VID header region left to
0xff).
Make sure we scrub the PEB in this case.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Fixes: dbb7d2a8 ("UBI: Add fastmap core")
Signed-off-by: NRichard Weinberger <richard@nod.at>

process_pool_aeb() does several times the be32_to_cpu(new_vh->vol_id)
operation. Create a temporary variable and do it once.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>

add_fastmap() is passed a ubi_vid_hdr pointer in argument, but is
referencing the global vidh pointer.
Even if this is correct from a functional point of view (vidh and vid_hdr
point to the same object), it is confusing.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>

process_pool_aeb() re-implements the logic found in ubi_find_volume().
Call ubi_find_volume() to avoid this duplication.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>

...don't waste memory by allocating one sizeof(int) per
PEB.
Signed-off-by: NRichard Weinberger <richard@nod.at>

Since PEB erasure is asynchornous it can happen that there is
more than one Fastmap on the MTD. This is fine because the attach logic
will pick the Fastmap data structure with the highest sequence number.

On a not so well configured MTD stack spurious ECC errors are common.
Causes can be different, bad hardware, wrong operating modes, etc...
If the most current Fastmap renders bad due to ECC errors UBI might
pick an older Fastmap to attach from.
While this can only happen on an anyway broken setup it will show
completely different sympthoms and makes finding the root cause much
more difficult.
So, be debug friendly and fall back to scanning mode of we're facing
an ECC error while scanning for Fastmap.

Cc: <stable@vger.kernel.org>
Signed-off-by: NRichard Weinberger <richard@nod.at>

This helps to detect cases where an user copies an UBI image to
another target with different bad blocks.
Signed-off-by: NRichard Weinberger <richard@nod.at>

Introduce a new list to the UBI attach information
object to be able to deal better with old and corrupted
Fastmap eraseblocks.
Also move more Fastmap specific code into fastmap.c.
Signed-off-by: NRichard Weinberger <richard@nod.at>

Signed-off-by: NRichard Weinberger <richard@nod.at>

This makes the logic more easy to follow.
Signed-off-by: NRichard Weinberger <richard@nod.at>

Signed-off-by: NRichard Weinberger <richard@nod.at>

When the volume resize operation shrinks a volume,
LEBs will be unmapped. Since unmapping will not erase these
LEBs immediately we have to wait for that operation to finish.
Otherwise in case of a power cut right after writing the new
volume table the UBI attach process can find more LEBs than the
volume table knows. This will render the UBI image unattachable.

Fix this issue by waiting for erase to complete and write the new
volume table afterward.

Cc: <stable@vger.kernel.org>
Reported-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Reviewed-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>

We cannot use ubi_* logging functions before the UBI
object is initialized.

Cc: <stable@vger.kernel.org>
Fixes: 32608703 ("UBI: Extend UBI layer debug/messaging capabilities")
Signed-off-by: NRichard Weinberger <richard@nod.at>

There is no need to call get/put on the module
reference in gluebi_get/put_device() callbacks.
Since mtd->owner is the gluebi module itself
mtdcore.c will take care of proper refcounting
in __get/put_mtd_device() before executing the
callbacks.
Signed-off-by: NRichard Weinberger <richard@nod.at>

Install the UBI device object before we arm sysfs.
Otherwise udev tries to read sysfs attributes before UBI is ready and
udev rules will not match.

Cc: <stable@vger.kernel.org>
Signed-off-by: NIosif Harutyunov <iharutyunov@sonicwall.com>
[rw: massaged commit message]
Signed-off-by: NRichard Weinberger <richard@nod.at>

When reading the vid hdr from the device UBI always reads a whole
page. Instead, read only the data we actually need and speed up
attachment of UBI devices by potentially making use of reading
subpages if the NAND driver supports it.

Since the VID header may be at offset vid_hdr_shift in the page and
we can only read from the beginning of a page we have to add that
offset to the read size.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NRichard Weinberger <richard@nod.at>

recover_peb() was never power cut aware,
if a power cut happened right after writing the VID header
upon next attach UBI would blindly use the new partial written
PEB and all data from the old PEB is lost.

In order to make recover_peb() power cut aware, write the new
VID with a proper crc and copy_flag set such that the UBI attach
process will detect whether the new PEB is completely written
or not.
We cannot directly use ubi_eba_atomic_leb_change() since we'd
have to unlock the LEB which is facing a write error.

Cc: stable@vger.kernel.org
Reported-by: NJörg Pfähler <pfaehler@isse.de>
Reviewed-by: NJörg Pfähler <pfaehler@isse.de>
Signed-off-by: NRichard Weinberger <richard@nod.at>

Directly accessing inode fields bypasses ->getattr()
and can cause problems when the underlying filesystem
does not have the default ->getattr() implementation.

So instead of obtaining the backing inode via d_backing_inode()
use vfs_getattr() and obtain what we need from the kstat struct.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Reported-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NRichard Weinberger <richard@nod.at>

This reverts commit 87f15d4a.

vfs_stat() can only be used on user supplied buffers.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NRichard Weinberger <richard@nod.at>

This reverts commit 322ea0bb.

vfs_stat() can only be used on user supplied buffers.
UBI's kapi.c is the API to the kernel and therefore vfs_stat()
is inappropriate.

This solves the problem that mounting any UBIFS will immediately
fail with -EINVAL.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NRichard Weinberger <richard@nod.at>

Ezequiel reported that he's facing UBI going into read-only
mode after power cut. It turned out that this behavior happens
only when updating a static volume is interrupted and Fastmap is
used.

A possible trace can look like:
ubi0 warning: ubi_io_read_vid_hdr [ubi]: no VID header found at PEB 2323, only 0xFF bytes
ubi0 warning: ubi_eba_read_leb [ubi]: switch to read-only mode
CPU: 0 PID: 833 Comm: ubiupdatevol Not tainted 4.6.0-rc2-ARCH #4
Hardware name: SAMSUNG ELECTRONICS CO., LTD. 300E4C/300E5C/300E7C/NP300E5C-AD8AR, BIOS P04RAP 10/15/2012
0000000000000286 00000000eba949bd ffff8800c45a7b38 ffffffff8140d841
ffff8801964be000 ffff88018eaa4800 ffff8800c45a7bb8 ffffffffa003abf6
ffffffff850e2ac0 8000000000000163 ffff8801850e2ac0 ffff8801850e2ac0
Call Trace:
[<ffffffff8140d841>] dump_stack+0x63/0x82
[<ffffffffa003abf6>] ubi_eba_read_leb+0x486/0x4a0 [ubi]
[<ffffffffa00453b3>] ubi_check_volume+0x83/0xf0 [ubi]
[<ffffffffa0039d97>] ubi_open_volume+0x177/0x350 [ubi]
[<ffffffffa00375d8>] vol_cdev_open+0x58/0xb0 [ubi]
[<ffffffff8124b08e>] chrdev_open+0xae/0x1d0
[<ffffffff81243bcf>] do_dentry_open+0x1ff/0x300
[<ffffffff8124afe0>] ? cdev_put+0x30/0x30
[<ffffffff81244d36>] vfs_open+0x56/0x60
[<ffffffff812545f4>] path_openat+0x4f4/0x1190
[<ffffffff81256621>] do_filp_open+0x91/0x100
[<ffffffff81263547>] ? __alloc_fd+0xc7/0x190
[<ffffffff812450df>] do_sys_open+0x13f/0x210
[<ffffffff812451ce>] SyS_open+0x1e/0x20
[<ffffffff81a99e32>] entry_SYSCALL_64_fastpath+0x1a/0xa4

UBI checks static volumes for data consistency and reads the
whole volume upon first open. If the volume is found erroneous
users of UBI cannot read from it, but another volume update is
possible to fix it. The check is performed by running
ubi_eba_read_leb() on every allocated LEB of the volume.
For static volumes ubi_eba_read_leb() computes the checksum of all
data stored in a LEB. To verify the computed checksum it has to read
the LEB's volume header which stores the original checksum.
If the volume header is not found UBI treats this as fatal internal
error and switches to RO mode. If the UBI device was attached via a
full scan the assumption is correct, the volume header has to be
present as it had to be there while scanning to get known as mapped.
If the attach operation happened via Fastmap the assumption is no
longer correct. When attaching via Fastmap UBI learns the mapping
table from Fastmap's snapshot of the system state and not via a full
scan. It can happen that a LEB got unmapped after a Fastmap was
written to the flash. Then UBI can learn the LEB still as mapped and
accessing it returns only 0xFF bytes. As UBI is not a FTL it is
allowed to have mappings to empty PEBs, it assumes that the layer
above takes care of LEB accounting and referencing.
UBIFS does so using the LEB property tree (LPT).
For static volumes UBI blindly assumes that all LEBs are present and
therefore special actions have to be taken.

The described situation can happen when updating a static volume is
interrupted, either by a user or a power cut.
The volume update code first unmaps all LEBs of a volume and then
writes LEB by LEB. If the sequence of operations is interrupted UBI
detects this either by the absence of LEBs, no volume header present
at scan time, or corrupted payload, detected via checksum.
In the Fastmap case the former method won't trigger as no scan
happened and UBI automatically thinks all LEBs are present.
Only by reading data from a LEB it detects that the volume header is
missing and incorrectly treats this as fatal error.
To deal with the situation ubi_eba_read_leb() from now on checks
whether we attached via Fastmap and handles the absence of a
volume header like a data corruption error.
This way interrupted static volume updates will correctly get detected
also when Fastmap is used.

Cc: <stable@vger.kernel.org>
Reported-by: NEzequiel Garcia <ezequiel@vanguardiasur.com.ar>
Tested-by: NEzequiel Garcia <ezequiel@vanguardiasur.com.ar>
Signed-off-by: NRichard Weinberger <richard@nod.at>

Set free_count to zero before walking through ai->erase list
in wl_init().

Found in U-Boot as U-Boot has no workqueue/threads, it immediately
calls erase_worker(), which increase for each erased block
free_count. Without this patch, free_count gets after
this initialized to zero in wl_init(), so the free_count
variable always has the maybe wrong value 0 in U-Boot.
Signed-off-by: NHeiko Schocher <hs@denx.de>
Reviewed-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>

My static checker complains that "val" is uninitialized when kstrtoint()
fails.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>

My static checker says that "err" can be uninitialized if
"vol->reserved_pebs" is <= 0.  I don't think that can happen but
returning a literal is cleaner anyway.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>

Signed-off-by: Nz00189512 <abc.zhangliang@huawei.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>

Drop this paranoia check from the old days.
If our MTD driver or the flash is so bad that we even cannot
trust it to write data we have bigger problems.

If one really does not trust the flash and wants write-verify
she can enable UBI io checks using debugfs.
Signed-off-by: NRichard Weinberger <richard@nod.at>

On serious situations, UBI may detect serious device corruption,
and switch to read-only mode to protect the data and allow debugging.
This commit exposes this ro-mode on sysfs, so it can be obtained
by userspace tools.
Signed-off-by: NEzequiel Garcia <ezequiel@vanguardiasur.com.ar>
Signed-off-by: NRichard Weinberger <richard@nod.at>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>