kernel/linux.git/drivers/mtd/ubi/fastmap.c, branch v6.1.168

ubi: correct the calculation of fastmap size

2024-04-03T13:19:27+00:00

[ Upstream commit 7f174ae4f39e8475adcc09d26c5a43394689ad6c ] Now that the calculation of fastmap size in ubi_calc_fm_size() is incorrect since it miss each user volume's ubi_fm_eba structure and the Internal UBI volume info. Let's correct the calculation. Cc: stable@vger.kernel.org Signed-off-by: Zhang Yi Reviewed-by: Zhihao Cheng Signed-off-by: Richard Weinberger Signed-off-by: Sasha Levin

ubi: fastmap: Use the bitmap API to allocate bitmaps

2022-09-21T09:32:58+00:00

Use bitmap_zalloc()/bitmap_free() instead of hand-writing them. It is less verbose and it improves the semantic. Signed-off-by: Christophe JAILLET Reviewed-by: Zhihao Cheng Signed-off-by: Richard Weinberger

ubi: fastmap: Fix high cpu usage of ubi_bgt by making sure wl_pool not empty

2022-05-27T14:46:02+00:00

There at least 6 PEBs reserved on UBI device: 1. EBA_RESERVED_PEBS[1] 2. WL_RESERVED_PEBS[1] 3. UBI_LAYOUT_VOLUME_EBS[2] 4. MIN_FASTMAP_RESERVED_PEBS[2] When all ubi volumes take all their PEBs, there are 3 (EBA_RESERVED_PEBS + WL_RESERVED_PEBS + MIN_FASTMAP_RESERVED_PEBS - MIN_FASTMAP_TAKEN_PEBS[1]) free PEBs. Since commit f9c34bb529975fe ("ubi: Fix producing anchor PEBs") and commit 4b68bf9a69d22dd ("ubi: Select fastmap anchor PEBs considering wear level rules") applied, there is only 1 (3 - FASTMAP_ANCHOR_PEBS[1] - FASTMAP_NEXT_ANCHOR_PEBS[1]) free PEB to fill pool and wl_pool, after filling pool, wl_pool is always empty. So, UBI could be stuck in an infinite loop: ubi_thread system_wq wear_leveling_worker <-------------------------------------------------- get_peb_for_wl | // fm_wl_pool, used = size = 0 | schedule_work(&ubi->fm_work) | | update_fastmap_work_fn | ubi_update_fastmap | ubi_refill_pools | // ubi->free_count - ubi->beb_rsvd_pebs < 5 | // wl_pool is not filled with any PEBs | schedule_erase(old_fm_anchor) | ubi_ensure_anchor_pebs | __schedule_ubi_work(wear_leveling_worker) | | __erase_worker | ensure_wear_leveling | __schedule_ubi_work(wear_leveling_worker) -------------------------- , which cause high cpu usage of ubi_bgt: top - 12:10:42 up 5 min, 2 users, load average: 1.76, 0.68, 0.27 Tasks: 123 total, 3 running, 54 sleeping, 0 stopped, 0 zombie PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 1589 root 20 0 0 0 0 R 45.0 0.0 0:38.86 ubi_bgt0d 319 root 20 0 0 0 0 I 15.2 0.0 0:15.29 kworker/0:3-eve 371 root 20 0 0 0 0 I 14.9 0.0 0:12.85 kworker/3:3-eve 20 root 20 0 0 0 0 I 11.3 0.0 0:05.33 kworker/1:0-eve 202 root 20 0 0 0 0 I 11.3 0.0 0:04.93 kworker/2:3-eve In commit 4b68bf9a69d22dd ("ubi: Select fastmap anchor PEBs considering wear level rules"), there are three key changes: 1) Choose the fastmap anchor when the most free PEBs are available. 2) Enable anchor move within the anchor area again as it is useful for distributing wear. 3) Import a candidate fm anchor and check this PEB's erase count during wear leveling. If the wear leveling limit is exceeded, use the used anchor area PEB with the lowest erase count to replace it. The anchor candidate can be removed, we can check fm_anchor PEB's erase count during wear leveling. Fix it by: 1) Removing 'fm_next_anchor' and check 'fm_anchor' during wear leveling. 2) Preferentially filling one free peb into fm_wl_pool in condition of ubi->free_count > ubi->beb_rsvd_pebs, then try to reserve enough free count for fastmap non anchor pebs after the above prerequisites are met. Then, there are at least 1 PEB in pool and 1 PEB in wl_pool after calling ubi_refill_pools() with all erase works done. Fetch a reproducer in [Link]. Fixes: 4b68bf9a69d22dd ("ubi: Select fastmap anchor PEBs ... rules") Link: https://bugzilla.kernel.org/show_bug.cgi?id=215407 Signed-off-by: Zhihao Cheng Signed-off-by: Richard Weinberger

ubi: fastmap: Return error code if memory allocation fails in add_aeb()

2022-01-10T22:09:08+00:00

Abort fastmap scanning and return error code if memory allocation fails in add_aeb(). Otherwise ubi will get wrong peb statistics information after scanning. Fixes: dbb7d2a88d2a7b ("UBI: Add fastmap core") Signed-off-by: Zhihao Cheng Signed-off-by: Richard Weinberger

ubi: Select fastmap anchor PEBs considering wear level rules

2020-06-02T20:53:05+00:00

There is a risk that the fastmap anchor PEB is alternating between just two PEBs, the current anchor and the previous anchor that was just deleted. As the fastmap pools gets the first take on free PEBs, the pools may leave no free PEBs to be selected as the new anchor, resulting in the two PEBs alternating behaviour. If the anchor PEBs gets a high erase count the PEBs will not be used by the pools but remain in ubi->free, even more increasing the likelihood they will be used as anchors. Getting stuck using only a couple of PEBs continuously will result in an uneven wear, eventually leading to failure. To fix this: - Choose the fastmap anchor when the most free PEBs are available. This is during rebuilding of the fastmap pools, after the unused pool PEBs are added to ubi->free but before the pools are populated again from the free PEBs. Also reserve an additional second best PEB as a candidate for the next time the fast map anchor is updated. If a better PEB is found the next time the fast map anchor is updated, the candidate is made available for building the pools. - Enable anchor move within the anchor area again as it is useful for distributing wear. - The anchor candidate for the next fastmap update is the most suited free PEB. Check this PEB's erase count during wear leveling. If the wear leveling limit is exceeded, the PEB is considered unsuitable for now. As all other non used anchor area PEBs should be even worse, free up the used anchor area PEB with the lowest erase count. Signed-off-by: Arne Edholm Signed-off-by: Richard Weinberger

ubi: Fix an error pointer dereference in error handling code

2020-01-19T22:23:28+00:00

If "seen_pebs = init_seen(ubi);" fails then "seen_pebs" is an error pointer and we try to kfree() it which results in an Oops. This patch re-arranges the error handling so now it only frees things which have been allocated successfully. Fixes: daef3dd1f0ae ("UBI: Fastmap: Add self check to detect absent PEBs") Signed-off-by: Dan Carpenter Signed-off-by: Richard Weinberger

ubi: fastmap: Fix inverted logic in seen selfcheck

2020-01-16T22:34:50+00:00

set_seen() sets the bit corresponding to the PEB number in the bitmap, so when self_check_seen() wants to find PEBs that haven't been seen we have to print the PEBs that have their bit cleared, not the ones which have it set. Fixes: 5d71afb00840 ("ubi: Use bitmaps in Fastmap self-check code") Signed-off-by: Sascha Hauer Signed-off-by: Richard Weinberger

ubi: Fix producing anchor PEBs

2019-11-17T21:45:57+00:00

When a new fastmap is about to be written UBI must make sure it has a free block for a fastmap anchor available. For this ubi_update_fastmap() calls ubi_ensure_anchor_pebs(). This stopped working with 2e8f08deabbc ("ubi: Fix races around ubi_refill_pools()"), with this commit the wear leveling code is blocked and can no longer produce free PEBs. UBI then more often than not falls back to write the new fastmap anchor to the same block it was already on which means the same erase block gets erased during each fastmap write and wears out quite fast. As the locking prevents us from producing the anchor PEB when we actually need it, this patch changes the strategy for creating the anchor PEB. We no longer create it on demand right before we want to write a fastmap, but instead we create an anchor PEB right after we have written a fastmap. This gives us enough time to produce a new anchor PEB before it is needed. To make sure we have an anchor PEB for the very first fastmap write we call ubi_ensure_anchor_pebs() during initialisation as well. Fixes: 2e8f08deabbc ("ubi: Fix races around ubi_refill_pools()") Signed-off-by: Sascha Hauer Signed-off-by: Richard Weinberger

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 286

2019-06-05T15:36:37+00:00

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation version 2 this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 97 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Allison Randal Reviewed-by: Alexios Zavras Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190529141901.025053186@linutronix.de Signed-off-by: Greg Kroah-Hartman

ubi: fastmap: Check each mapping only once

2018-06-07T13:53:16+00:00

Maintain a bitmap to keep track of which LEB->PEB mapping was checked already. That way we have to read back VID headers only once. Signed-off-by: Richard Weinberger