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

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

Use the new WL accessor functions in fastmap.

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

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: Richard 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: Richard 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: Richard Weinberger <richard@nod.at>

If we set it for dynamic ones we might confuse various self checks.

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