kernel/linux.git/block/badblocks.c, branch v6.12.80

badblocks: Fix a nonsense WARN_ON() which checks whether a u64 variable < 0

2025-05-29T09:02:24+00:00

[ Upstream commit 7e76336e14de9a2b67af96012ddd46c5676cf340 ] In _badblocks_check(), there are lines of code like this, 1246 sectors -= len; [snipped] 1251 WARN_ON(sectors < 0); The WARN_ON() at line 1257 doesn't make sense because sectors is unsigned long long type and never to be <0. Fix it by checking directly checking whether sectors is less than len. Reported-by: Dan Carpenter Signed-off-by: Coly Li Reviewed-by: Yu Kuai Link: https://lore.kernel.org/r/20250309160556.42854-1-colyli@kernel.org Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

badblocks: avoid checking invalid range in badblocks_check()

2023-12-24T01:38:08+00:00

If prev_badblocks() returns '-1', it means no valid badblocks record before the checking range. It doesn't make sense to check whether the input checking range is overlapped with the non-existed invalid front range. This patch checkes whether 'prev >= 0' is true before calling overlap_front(), to void such invalid operations. Fixes: 3ea3354cb9f0 ("badblocks: improve badblocks_check() for multiple ranges handling") Reported-and-tested-by: Ira Weiny Signed-off-by: Coly Li Link: https://lore.kernel.org/nvdimm/3035e75a-9be0-4bc3-8d4a-6e52c207f277@leemhuis.info/ Cc: Dan Williams Cc: Geliang Tang Cc: Hannes Reinecke Cc: Jens Axboe Cc: NeilBrown Cc: Vishal L Verma Cc: Xiao Ni Link: https://lore.kernel.org/r/20231224002820.20234-1-colyli@suse.de Signed-off-by: Jens Axboe

badblocks: switch to the improved badblock handling code

2023-09-26T06:44:33+00:00

This patch removes old code of badblocks_set(), badblocks_clear() and badblocks_check(), and make them as wrappers to call _badblocks_set(), _badblocks_clear() and _badblocks_check(). By this change now the badblock handing switch to the improved algorithm in _badblocks_set(), _badblocks_clear() and _badblocks_check(). This patch only contains the changes of old code deletion, new added code for the improved algorithms are in previous patches. Signed-off-by: Coly Li Cc: Dan Williams Cc: Geliang Tang Cc: Hannes Reinecke Cc: Jens Axboe Cc: NeilBrown Cc: Vishal L Verma Cc: Xiao Ni Reviewed-by: Xiao Ni Acked-by: Geliang Tang Link: https://lore.kernel.org/r/20230811170513.2300-7-colyli@suse.de Signed-off-by: Jens Axboe

badblocks: improve badblocks_check() for multiple ranges handling

2023-09-26T06:44:33+00:00

This patch rewrites badblocks_check() with similar coding style as _badblocks_set() and _badblocks_clear(). The only difference is bad blocks checking may handle multiple ranges in bad tables now. If a checking range covers multiple bad blocks range in bad block table, like the following condition (C is the checking range, E1, E2, E3 are three bad block ranges in bad block table), +------------------------------------+ | C | +------------------------------------+ +----+ +----+ +----+ | E1 | | E2 | | E3 | +----+ +----+ +----+ The improved badblocks_check() algorithm will divide checking range C into multiple parts, and handle them in 7 runs of a while-loop, +--+ +----+ +----+ +----+ +----+ +----+ +----+ |C1| | C2 | | C3 | | C4 | | C5 | | C6 | | C7 | +--+ +----+ +----+ +----+ +----+ +----+ +----+ +----+ +----+ +----+ | E1 | | E2 | | E3 | +----+ +----+ +----+ And the start LBA and length of range E1 will be set as first_bad and bad_sectors for the caller. The return value rule is consistent for multiple ranges. For example if there are following bad block ranges in bad block table, Index No. Start Len Ack 0 400 20 1 1 500 50 1 2 650 20 0 the return value, first_bad, bad_sectors by calling badblocks_set() with different checking range can be the following values, Checking Start, Len Return Value first_bad bad_sectors 100, 100 0 N/A N/A 100, 310 1 400 10 100, 440 1 400 10 100, 540 1 400 10 100, 600 -1 400 10 100, 800 -1 400 10 In order to make code review easier, this patch names the improved bad block range checking routine as _badblocks_check() and does not change existing badblock_check() code yet. Later patch will delete old code of badblocks_check() and make it as a wrapper to call _badblocks_check(). Then the new added code won't mess up with the old deleted code, it will be more clear and easier for code review. Signed-off-by: Coly Li Cc: Dan Williams Cc: Geliang Tang Cc: Hannes Reinecke Cc: Jens Axboe Cc: NeilBrown Cc: Vishal L Verma Cc: Xiao Ni Reviewed-by: Xiao Ni Acked-by: Geliang Tang Link: https://lore.kernel.org/r/20230811170513.2300-6-colyli@suse.de Signed-off-by: Jens Axboe

badblocks: improve badblocks_clear() for multiple ranges handling

2023-09-26T06:44:33+00:00

With the fundamental ideas and helper routines from badblocks_set() improvement, clearing bad block for multiple ranges is much simpler. With a similar idea from badblocks_set() improvement, this patch simplifies bad block range clearing into 5 situations. No matter how complicated the clearing condition is, we just look at the head part of clearing range with relative already set bad block range from the bad block table. The rested part will be handled in next run of the while-loop. Based on existing helpers added from badblocks_set(), this patch adds two more helpers, - front_clear() Clear the bad block range from bad block table which is front overlapped with the clearing range. - front_splitting_clear() Handle the condition that the clearing range hits middle of an already set bad block range from bad block table. Similar as badblocks_set(), the first part of clearing range is handled with relative bad block range which is find by prev_badblocks(). In most cases a valid hint is provided to prev_badblocks() to avoid unnecessary bad block table iteration. This patch also explains the detail algorithm code comments at beginning of badblocks.c, including which five simplified situations are categrized and how all the bad block range clearing conditions are handled by these five situations. Again, in order to make the code review easier and avoid the code changes mixed together, this patch does not modify badblock_clear() and implement another routine called _badblock_clear() for the improvement. Later patch will delete current code of badblock_clear() and make it as a wrapper to _badblock_clear(), so the code change can be much clear for review. Signed-off-by: Coly Li Cc: Dan Williams Cc: Geliang Tang Cc: Hannes Reinecke Cc: Jens Axboe Cc: NeilBrown Cc: Vishal L Verma Cc: Xiao Ni Reviewed-by: Xiao Ni Acked-by: Geliang Tang Link: https://lore.kernel.org/r/20230811170513.2300-5-colyli@suse.de Signed-off-by: Jens Axboe

badblocks: improve badblocks_set() for multiple ranges handling

2023-09-26T06:44:33+00:00

Recently I received a bug report that current badblocks code does not properly handle multiple ranges. For example, badblocks_set(bb, 32, 1, true); badblocks_set(bb, 34, 1, true); badblocks_set(bb, 36, 1, true); badblocks_set(bb, 32, 12, true); Then indeed badblocks_show() reports, 32 3 36 1 But the expected bad blocks table should be, 32 12 Obviously only the first 2 ranges are merged and badblocks_set() returns and ignores the rest setting range. This behavior is improper, if the caller of badblocks_set() wants to set a range of blocks into bad blocks table, all of the blocks in the range should be handled even the previous part encountering failure. The desired way to set bad blocks range by badblocks_set() is, - Set as many as blocks in the setting range into bad blocks table. - Merge the bad blocks ranges and occupy as less as slots in the bad blocks table. - Fast. Indeed the above proposal is complicated, especially with the following restrictions, - The setting bad blocks range can be acknowledged or not acknowledged. - The bad blocks table size is limited. - Memory allocation should be avoided. The basic idea of the patch is to categorize all possible bad blocks range setting combinations into much less simplified and more less special conditions. Inside badblocks_set() there is an implicit loop composed by jumping between labels 're_insert' and 'update_sectors'. No matter how large the setting bad blocks range is, in every loop just a minimized range from the head is handled by a pre-defined behavior from one of the categorized conditions. The logic is simple and code flow is manageable. The different relative layout between the setting range and existing bad block range are checked and handled (merge, combine, overwrite, insert) by the helpers in previous patch. This patch is to make all the helpers work together with the above idea. This patch only has the algorithm improvement for badblocks_set(). There are following patches contain improvement for badblocks_clear() and badblocks_check(). But the algorithm in badblocks_set() is fundamental and typical, other improvement in clear and check routines are based on all the helpers and ideas in this patch. In order to make the change to be more clear for code review, this patch does not directly modify existing badblocks_set(), and just add a new one named _badblocks_set(). Later patch will remove current existing badblocks_set() code and make it as a wrapper of _badblocks_set(). So the new added change won't be mixed with deleted code, the code review can be easier. Signed-off-by: Coly Li Cc: Dan Williams Cc: Geliang Tang Cc: Hannes Reinecke Cc: Jens Axboe Cc: NeilBrown Cc: Vishal L Verma Cc: Wols Lists Cc: Xiao Ni Reviewed-by: Xiao Ni Acked-by: Geliang Tang Link: https://lore.kernel.org/r/20230811170513.2300-4-colyli@suse.de Signed-off-by: Jens Axboe

badblocks: add helper routines for badblock ranges handling

2023-09-26T06:44:33+00:00

This patch adds several helper routines to improve badblock ranges handling. These helper routines will be used later in the improved version of badblocks_set()/badblocks_clear()/badblocks_check(). - Helpers prev_by_hint() and prev_badblocks() are used to find the bad range from bad table which the searching range starts at or after. - The following helpers are to decide the relative layout between the manipulating range and existing bad block range from bad table. - can_merge_behind() Return 'true' if the manipulating range can backward merge with the bad block range. - can_merge_front() Return 'true' if the manipulating range can forward merge with the bad block range. - can_combine_front() Return 'true' if two adjacent bad block ranges before the manipulating range can be merged. - overlap_front() Return 'true' if the manipulating range exactly overlaps with the bad block range in front of its range. - overlap_behind() Return 'true' if the manipulating range exactly overlaps with the bad block range behind its range. - can_front_overwrite() Return 'true' if the manipulating range can forward overwrite the bad block range in front of its range. - The following helpers are to add the manipulating range into the bad block table. Different routine is called with the specific relative layout between the manipulating range and other bad block range in the bad block table. - behind_merge() Merge the manipulating range with the bad block range behind its range, and return the number of merged length in unit of sector. - front_merge() Merge the manipulating range with the bad block range in front of its range, and return the number of merged length in unit of sector. - front_combine() Combine the two adjacent bad block ranges before the manipulating range into a larger one. - front_overwrite() Overwrite partial of whole bad block range which is in front of the manipulating range. The overwrite may split existing bad block range and generate more bad block ranges into the bad block table. - insert_at() Insert the manipulating range at a specific location in the bad block table. All the above helpers are used in later patches to improve the bad block ranges handling for badblocks_set()/badblocks_clear()/badblocks_check(). Signed-off-by: Coly Li Cc: Dan Williams Cc: Geliang Tang Cc: Hannes Reinecke Cc: Jens Axboe Cc: NeilBrown Cc: Vishal L Verma Cc: Xiao Ni Reviewed-by: Xiao Ni Acked-by: Geliang Tang Link: https://lore.kernel.org/r/20230811170513.2300-3-colyli@suse.de Signed-off-by: Jens Axboe

block/badblocks: Remove redundant assignments

2022-04-23T13:15:26+00:00

Get rid of redundant assignments to a variable sectors from functions badblocks_check and badblocks_clear. This variable, that is a function parameter, is being assigned a value that is never read until the end of function. Reported by clang-tidy [deadcode.DeadStores] Signed-off-by: Michal Orzel Link: https://lore.kernel.org/r/20220423113811.13335-1-michalorzel.eng@gmail.com Signed-off-by: Jens Axboe

treewide: Use fallthrough pseudo-keyword

2020-08-23T22:36:59+00:00

Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva

block: switch all files cleared marked as GPLv2 to SPDX tags

2019-04-30T22:11:57+00:00

All these files have some form of the usual GPLv2 boilerplate. Switch them to use SPDX tags instead. Reviewed-by: Chaitanya Kulkarni Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe