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>

Using logging functions instead of macros can reduce overall object size.

$ size drivers/mtd/ubi/built-in.o*
   text	   data	    bss	    dec	    hex	filename
 271620	 163364	  73696	 508680	  7c308	drivers/mtd/ubi/built-in.o.allyesconfig.new
 287638	 165380	  73504	 526522	  808ba	drivers/mtd/ubi/built-in.o.allyesconfig.old
  87728	   3780	    504	  92012	  1676c	drivers/mtd/ubi/built-in.o.defconfig.new
  97084	   3780	    504	 101368	  18bf8	drivers/mtd/ubi/built-in.o.defconfig.old
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>

ubi_start_leb_change() allocates too few bytes.
ubi_more_leb_change_data() will write up to req->upd_bytes +
ubi->min_io_size bytes.

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

parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested},
inode_foo(inode) being mutex_foo(&inode->i_mutex).

Please, use those for access to ->i_mutex; over the coming cycle
->i_mutex will become rwsem, with ->lookup() done with it held
only shared.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

wear_leveling_worker() currently unconditionally puts a PEB on erase in
the error case even it just been taken from the free_list and never
used.
In case the PEB was never used it can be put back on the free list
saving a precious erase cycle.

v1…v2:
	- to_leb_clean -> dst_leb_clean
	- use the nested option for ensure_wear_leveling()
	- do_sync_erase() can't go -ENOMEM so we can just go into
	  RO-mode now.
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NRichard Weinberger <richard@nod.at>

If __erase_worker() fails to erase the EB and schedule_erase() fails as
well to do anything about it then we go RO. But that is not a reason to
leak the e argument here. Therefore clean up e.

Cc: <stable@vger.kernel.org>
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NRichard Weinberger <richard@nod.at>

Since fastmap we gained do_sync_erase(). This function can return an error
and its error handling isn't obvious. First the memory allocation for
struct ubi_work can fail and as such struct ubi_wl_entry is leaked.
However if the memory allocation succeeds then the tail function takes
care of the struct ubi_wl_entry. A free here could result in a double
free.
To make the error handling simpler, I split the tail function into one
piece which does the work and another which frees the struct ubi_work
which is passed as argument. As result do_sync_erase() can keep the
struct on stack and we get rid of one error source.

Cc: <stable@vger.kernel.org>
Fixes: 8199b901 ("UBI: Add fastmap support to the WL sub-system")
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NRichard Weinberger <richard@nod.at>

Looks like a typo, using UBI_EC_HDR_SIZE_CRC (note the "EC") to compute
the CRC for the VID header.

This shouldn't cause any functional change, as both structures are 64
bytes. Verified with:

	BUILD_BUG_ON(UBI_VID_HDR_SIZE_CRC != UBI_EC_HDR_SIZE_CRC);

Reported here:
http://lists.infradead.org/pipermail/linux-mtd/2013-September/048570.html

Reported by: Bill Pringlemeir <bpringlemeir@gmail.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>

We are checking dfs_rootdir for error value or NULL. But in the
conditional ternary operator we returned -ENODEV if dfs_rootdir contains
an error value and returned PTR_ERR(dfs_rootdir) if dfs_rootdir is NULL.
So in the case of dfs_rootdir being NULL we actually assigned 0 to err
and returned it to the caller implying a success.
Lets return -ENODEV when dfs_rootdir is NULL else return
PTR_ERR(dfs_rootdir).
Signed-off-by: NSudip Mukherjee <sudip@vectorindia.org>
Signed-off-by: NRichard Weinberger <richard@nod.at>

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

The PEB array is an array of __be32, so let's fix the
scan_pool() prototype accordingly.
Signed-off-by: NEzequiel Garcia <ezequiel@vanguardiasur.com.ar>
Signed-off-by: NRichard Weinberger <richard@nod.at>

If fastmap requests a free PEB for a pool and UBI is busy
with erasing PEBs we need to offer a function to wait for one.
We can reuse produce_free_peb() from the non-fastmap WL code
but with different locking semantics.

Cc: stable@vger.kernel.org # 4.1.x-
Reported-and-tested-by: NJörg Krause <joerg.krause@embedded.rocks>
Signed-off-by: NRichard Weinberger <richard@nod.at>

Remove unneeded NULL test.

The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@ expression x; @@
-if (x != NULL)
  \(kmem_cache_destroy\|mempool_destroy\|dma_pool_destroy\)(x);
// </smpl>
Signed-off-by: NJulia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: NRichard Weinberger <richard@nod.at>

This patch trivially updates code comments to reflect the addition of the
UBI_METAONLY flag - as discussed https://lkml.org/lkml/2014/10/29/764

Cc: Richard Weinberger <richard@nod.at>
Cc: trivial@kernel.org
Signed-off-by: NAndrew Murray <amurray@embedded-bits.co.uk>
Signed-off-by: NRichard Weinberger <richard@nod.at>

We have to use j instead of i. i is the volume id
and not the block.

Reported-by: Alexander.Block@continental-corporation.com
Signed-off-by: NRichard Weinberger <richard@nod.at>
Acked-by: NBrian Norris <computersforpeace@gmail.com>

While we are here fix a s/beween/between typo.
Signed-off-by: NRichard Weinberger <richard@nod.at>
Acked-by: NBrian Norris <computersforpeace@gmail.com>

There is no need to compute pnum again.
Signed-off-by: NRichard Weinberger <richard@nod.at>
Acked-by: NBrian Norris <computersforpeace@gmail.com>

This patch trivially updates code comments to reflect the addition of the
UBI_METAONLY flag - as discussed https://lkml.org/lkml/2014/10/29/764

Cc: Richard Weinberger <richard@nod.at>
Cc: trivial@kernel.org
Signed-off-by: NAndrew Murray <amurray@embedded-bits.co.uk>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

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>