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path: root/drivers/mtd/ubi/fastmap-wl.c
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2020-08-02ubi: fastmap: Free fastmap next anchor peb during detachZhihao Cheng
ubi_wl_entry related with the fm_next_anchor PEB is not freed during detach, which causes a memory leak. Don't forget to release fm_next_anchor PEB while detaching ubi from mtd when CONFIG_MTD_UBI_FASTMAP is enabled. Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com> Fixes: 4b68bf9a69d22d ("ubi: Select fastmap anchor PEBs considering...") Signed-off-by: Richard Weinberger <richard@nod.at>
2020-06-02ubi: Select fastmap anchor PEBs considering wear level rulesArne Edholm
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 <arne.edholm@axis.com> Signed-off-by: Richard Weinberger <richard@nod.at>
2020-03-30ubi: fastmap: Free unused fastmap anchor peb during detachHou Tao
When CONFIG_MTD_UBI_FASTMAP is enabled, fm_anchor will be assigned a free PEB during ubi_wl_init() or ubi_update_fastmap(). However if fastmap is not used or disabled on the MTD device, ubi_wl_entry related with the PEB will not be freed during detach. So Fix it by freeing the unused fastmap anchor during detach. Fixes: f9c34bb52997 ("ubi: Fix producing anchor PEBs") Reported-by: syzbot+f317896aae32eb281a58@syzkaller.appspotmail.com Reviewed-by: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Hou Tao <houtao1@huawei.com> Signed-off-by: Richard Weinberger <richard@nod.at>
2019-11-17ubi: Fix producing anchor PEBsSascha Hauer
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 <s.hauer@pengutronix.de> Signed-off-by: Richard Weinberger <richard@nod.at>
2019-09-15ubi: ubi_wl_get_peb: Increase the number of attempts while getting PEBZhihao Cheng
Running stress test io_paral (A pressure ubi test in mtd-utils) on an UBI device with fewer PEBs (fastmap enabled) may cause ENOSPC errors and make UBI device read-only, but there are still free PEBs on the UBI device. This problem can be easily reproduced by performing the following steps on a 2-core machine: $ modprobe nandsim first_id_byte=0x20 second_id_byte=0x33 parts=80 $ modprobe ubi mtd="0,0" fm_autoconvert $ ./io_paral /dev/ubi0 We may see the following verbose: (output) [io_paral] update_volume():108: failed to write 380 bytes at offset 95920 of volume 2 [io_paral] update_volume():109: update: 97088 bytes [io_paral] write_thread():227: function pwrite() failed with error 28 (No space left on device) [io_paral] write_thread():229: cannot write 15872 bytes to offs 31744, wrote -1 (dmesg) ubi0 error: ubi_wl_get_peb [ubi]: Unable to get a free PEB from user WL pool ubi0 warning: ubi_eba_write_leb [ubi]: switch to read-only mode CPU: 0 PID: 2027 Comm: io_paral Not tainted 5.3.0-rc2-00001-g5986cd0 #9 ubi0 warning: try_write_vid_and_data [ubi]: failed to write VID header to LEB 2:5, PEB 18 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0 -0-ga698c8995f-prebuilt.qemu.org 04/01/2014 Call Trace: dump_stack+0x85/0xba ubi_eba_write_leb+0xa1e/0xa40 [ubi] vol_cdev_write+0x307/0x520 [ubi] vfs_write+0xfa/0x280 ksys_pwrite64+0xc5/0xe0 __x64_sys_pwrite64+0x22/0x30 do_syscall_64+0xbf/0x440 In function ubi_wl_get_peb, the operation of filling the pool (ubi_update_fastmap) with free PEBs and fetching a free PEB from the pool is not atomic. After thread A filling the pool with free PEB, free PEB may be taken away by thread B. When thread A checks the expression again, the condition is still unsatisfactory. At this time, there may still be free PEBs on UBI that can be filled into the pool. This patch increases the number of attempts to obtain PEB. An extreme case (No free PEBs left after creating test volumes) has been tested on different type of machines for 100 times. The biggest number of attempts are shown below: x86_64 arm64 2-core 4 4 4-core 8 4 8-core 4 4 Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com> Signed-off-by: Richard Weinberger <richard@nod.at>
2019-06-05treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 286Thomas Gleixner
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 <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190529141901.025053186@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-04ubi: fastmap: Don't flush fastmap work on detachRichard Weinberger
At this point UBI volumes have already been free()'ed and fastmap can no longer access these data structures. Reported-by: Martin Townsend <mtownsend1973@gmail.com> Fixes: 74cdaf24004a ("UBI: Fastmap: Fix memory leaks while closing the WL sub-system") Cc: stable@vger.kernel.org Signed-off-by: Richard Weinberger <richard@nod.at>
2018-01-18ubi: Fastmap: Fix typoSascha Hauer
Fix misspelling of 'available' in function name. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Richard Weinberger <richard@nod.at>
2016-10-02ubi: Fix races around ubi_refill_pools()Richard Weinberger
When writing a new Fastmap the first thing that happens is refilling the pools in memory. At this stage it is possible that new PEBs from the new pools get already claimed and written with data. If this happens before the new Fastmap data structure hits the flash and we face power cut the freshly written PEB will not scanned and unnoticed. Solve the issue by locking the pools until Fastmap is written. Cc: <stable@vger.kernel.org> Fixes: dbb7d2a88d ("UBI: Add fastmap core") Signed-off-by: Richard Weinberger <richard@nod.at>
2015-10-03ubi: fastmap: Implement produce_free_peb()Richard Weinberger
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: Jörg Krause <joerg.krause@embedded.rocks> Signed-off-by: Richard Weinberger <richard@nod.at>
2015-03-26UBI: Fastmap: Remove is_fm_block()Richard Weinberger
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: Richard Weinberger <richard@nod.at>
2015-03-26UBI: Fastmap: Add blank line after declarationsRichard Weinberger
Another checkpatch complaint: WARNING: Missing a blank line after declarations Signed-off-by: Richard Weinberger <richard@nod.at>
2015-03-26UBI: Fastmap: Remove else after return.Richard Weinberger
checkpatch.pl complains: WARNING: else is not generally useful after a break or return Signed-off-by: Richard Weinberger <richard@nod.at>
2015-03-26UBI: Fastmap: Introduce may_reserve_for_fm()Richard Weinberger
...and kill another #ifdef. Signed-off-by: Richard Weinberger <richard@nod.at>
2015-03-26UBI: Move fastmap specific functions out of wl.cRichard Weinberger
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: Richard Weinberger <richard@nod.at>