kernel/linux.git/drivers/mtd/ubi/fastmap.c, branch v6.19.11

ubi: correct the calculation of fastmap size

2024-02-25T20:30:15+00:00

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

ubi: fastmap: Wait until there are enough free PEBs before filling pools

2023-10-28T20:43:40+00:00

Wait until there are enough free PEBs before filling pool/wl_pool, sometimes erase_worker is not scheduled in time, which causes two situations: A. There are few PEBs filled in pool, which makes ubi_update_fastmap is frequently called and leads first 64 PEBs are erased more times than other PEBs. So waiting free PEBs before filling pool reduces fastmap updating frequency and prolongs flash service life. B. In situation that space is nearly running out, ubi_refill_pools() cannot make sure pool and wl_pool are filled with free PEBs, caused by the delay of erase_worker. After this patch applied, there must exist free PEBs in pool after one call of ubi_update_fastmap. Besides, this patch is a preparetion for fixing large erase counter in fastmap data block and fixing lapsed wear leveling for first 64 PEBs. Link: https://bugzilla.kernel.org/show_bug.cgi?id=217787 Signed-off-by: Zhihao Cheng Signed-off-by: Richard Weinberger

ubi: Replace erase_block() with sync_erase()

2023-10-28T20:34:24+00:00

Since erase_block() has same logic with sync_erase(), just replace it with sync_erase(), also rename 'sync_erase()' to 'ubi_sync_erase()'. Signed-off-by: Zhihao Cheng Signed-off-by: Richard Weinberger

ubi: fastmap: Allocate memory with GFP_NOFS in ubi_update_fastmap

2023-10-28T20:33:39+00:00

Function ubi_update_fastmap could be called in IO context, for example: ubifs_writepage do_writepage ubifs_jnl_write_data write_head ubifs_wbuf_write_nolock ubifs_leb_write ubi_leb_write ubi_eba_write_leb try_write_vid_and_data ubi_wl_get_peb ubi_update_fastmap erase_block So it's better to allocate memory with GFP_NOFS mode, in case waiting page writeback(dead loop). Signed-off-by: Zhihao Cheng Signed-off-by: Richard Weinberger

ubi: fastmap: erase_block: Get erase counter from wl_entry rather than flash

2023-10-28T20:32:58+00:00

Just like sync_erase() does, getting erase counter from wl_entry is faster than reading from flash. Signed-off-by: Zhihao Cheng Signed-off-by: Richard Weinberger

ubi: fastmap: Fix missed ec updating after erasing old fastmap data block

2023-10-28T20:30:01+00:00

After running fsstress on ubifs for a long time, UBI(16384 blocks, fastmap takes 2 blocks) has an erase block with different erase counters displayed from two views: From ubiscan view: PEB 8031 has erase counter 31581 ========================================================= from to count min avg max --------------------------------------------------------- 0 .. 9: 0 0 0 0 10 .. 99: 0 0 0 0 100 .. 999: 16383 290 315 781 1000 .. 9999: 0 0 0 0 10000 .. 99999: 1 31581 31581 31581 100000 .. inf: 0 0 0 0 --------------------------------------------------------- Total : 16384 290 317 31581 From detailed_erase_block_info view: PEB 8031 has erase counter 7 physical_block_number erase_count 8030 421 8031 7 # mem info is different from disk info 8032 434 8033 425 8034 431 Following process missed updating erase counter in wl_entry(in memory): ubi_update_fastmap for (i = 1; i < new_fm->used_blocks; i++) // update fastmap data if (!tmp_e) if (old_fm && old_fm->e[i]) erase_block(ubi, old_fm->e[i]->pnum) ret = ubi_io_sync_erase(ubi, pnum, 0) ec = be64_to_cpu(ec_hdr->ec) ec += ret ec_hdr->ec = cpu_to_be64(ec) ubi_io_write_ec_hdr(ubi, pnum, ec_hdr) // ec is updated on flash // ec is not updated in old_fm->e[i] (in memory) Fix it by passing wl_enter into erase_block() and updating erase counter in erase_block(). Fixes: dbb7d2a88d2a ("UBI: Add fastmap core") Signed-off-by: Zhihao Cheng Signed-off-by: Richard Weinberger

UBI: Fastmap: Fix kernel-doc

2023-02-02T20:13:51+00:00

drivers/mtd/ubi/fastmap.c:104: warning: expecting prototype for new_fm_vhdr(). Prototype was for new_fm_vbuf() instead. Link: https://bugzilla.openanolis.cn/show_bug.cgi?id=2289 Reported-by: Abaci Robot Signed-off-by: Jiapeng Chong Signed-off-by: Richard Weinberger

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