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2023-12-23badblocks: avoid checking invalid range in badblocks_check()Coly Li
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 <ira.weiny@intel.com> Signed-off-by: Coly Li <colyli@suse.de> Link: https://lore.kernel.org/nvdimm/3035e75a-9be0-4bc3-8d4a-6e52c207f277@leemhuis.info/ Cc: Dan Williams <dan.j.williams@intel.com> Cc: Geliang Tang <geliang.tang@suse.com> Cc: Hannes Reinecke <hare@suse.de> Cc: Jens Axboe <axboe@kernel.dk> Cc: NeilBrown <neilb@suse.de> Cc: Vishal L Verma <vishal.l.verma@intel.com> Cc: Xiao Ni <xni@redhat.com> Link: https://lore.kernel.org/r/20231224002820.20234-1-colyli@suse.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-09-26badblocks: switch to the improved badblock handling codeColy Li
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 <colyli@suse.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Geliang Tang <geliang.tang@suse.com> Cc: Hannes Reinecke <hare@suse.de> Cc: Jens Axboe <axboe@kernel.dk> Cc: NeilBrown <neilb@suse.de> Cc: Vishal L Verma <vishal.l.verma@intel.com> Cc: Xiao Ni <xni@redhat.com> Reviewed-by: Xiao Ni <xni@redhat.com> Acked-by: Geliang Tang <geliang.tang@suse.com> Link: https://lore.kernel.org/r/20230811170513.2300-7-colyli@suse.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-09-26badblocks: improve badblocks_check() for multiple ranges handlingColy Li
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 <colyli@suse.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Geliang Tang <geliang.tang@suse.com> Cc: Hannes Reinecke <hare@suse.de> Cc: Jens Axboe <axboe@kernel.dk> Cc: NeilBrown <neilb@suse.de> Cc: Vishal L Verma <vishal.l.verma@intel.com> Cc: Xiao Ni <xni@redhat.com> Reviewed-by: Xiao Ni <xni@redhat.com> Acked-by: Geliang Tang <geliang.tang@suse.com> Link: https://lore.kernel.org/r/20230811170513.2300-6-colyli@suse.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-09-26badblocks: improve badblocks_clear() for multiple ranges handlingColy Li
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 <colyli@suse.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Geliang Tang <geliang.tang@suse.com> Cc: Hannes Reinecke <hare@suse.de> Cc: Jens Axboe <axboe@kernel.dk> Cc: NeilBrown <neilb@suse.de> Cc: Vishal L Verma <vishal.l.verma@intel.com> Cc: Xiao Ni <xni@redhat.com> Reviewed-by: Xiao Ni <xni@redhat.com> Acked-by: Geliang Tang <geliang.tang@suse.com> Link: https://lore.kernel.org/r/20230811170513.2300-5-colyli@suse.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-09-26badblocks: improve badblocks_set() for multiple ranges handlingColy Li
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 <colyli@suse.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Geliang Tang <geliang.tang@suse.com> Cc: Hannes Reinecke <hare@suse.de> Cc: Jens Axboe <axboe@kernel.dk> Cc: NeilBrown <neilb@suse.de> Cc: Vishal L Verma <vishal.l.verma@intel.com> Cc: Wols Lists <antlists@youngman.org.uk> Cc: Xiao Ni <xni@redhat.com> Reviewed-by: Xiao Ni <xni@redhat.com> Acked-by: Geliang Tang <geliang.tang@suse.com> Link: https://lore.kernel.org/r/20230811170513.2300-4-colyli@suse.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-09-26badblocks: add helper routines for badblock ranges handlingColy Li
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 <colyli@suse.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Geliang Tang <geliang.tang@suse.com> Cc: Hannes Reinecke <hare@suse.de> Cc: Jens Axboe <axboe@kernel.dk> Cc: NeilBrown <neilb@suse.de> Cc: Vishal L Verma <vishal.l.verma@intel.com> Cc: Xiao Ni <xni@redhat.com> Reviewed-by: Xiao Ni <xni@redhat.com> Acked-by: Geliang Tang <geliang.tang@suse.com> Link: https://lore.kernel.org/r/20230811170513.2300-3-colyli@suse.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-04-23block/badblocks: Remove redundant assignmentsMichal Orzel
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 <michalorzel.eng@gmail.com> Link: https://lore.kernel.org/r/20220423113811.13335-1-michalorzel.eng@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-08-23treewide: Use fallthrough pseudo-keywordGustavo A. R. Silva
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 <gustavoars@kernel.org>
2019-04-30block: switch all files cleared marked as GPLv2 to SPDX tagsChristoph Hellwig
All these files have some form of the usual GPLv2 boilerplate. Switch them to use SPDX tags instead. Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-03badblocks: fix wrong return value in badblocks_set if badblocks are disabledLiu Bo
MD's rdev_set_badblocks() expects that badblocks_set() returns 1 if badblocks are disabled, otherwise, rdev_set_badblocks() will record superblock changes and return success in that case and md will fail to report an IO error which it should. This bug has existed since badblocks were introduced in commit 9e0e252a048b ("badblocks: Add core badblock management code"). Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Acked-by: Guoqing Jiang <gqjiang@suse.com> Signed-off-by: Shaohua Li <shli@fb.com>
2017-06-21block: Add fallthrough markers to switch statementsBart Van Assche
This patch suppresses gcc 7 warnings about falling through in switch statements when building with W=1. From the gcc documentation: The -Wimplicit-fallthrough=3 warning is enabled by -Wextra. See also https://gcc.gnu.org/onlinedocs/gcc-7.1.0/gcc/Warning-Options.html. Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2016-10-21badblocks: badblocks_set/clear update unacked_existShaohua Li
When bandblocks_set acknowledges a range or badblocks_clear a range, it's possible all badblocks are acknowledged. We should update unacked_exist if this occurs. Signed-off-by: Shaohua Li <shli@fb.com> Reviewed-by: Tomasz Majchrzak <tomasz.majchrzak@intel.com> Tested-by: Tomasz Majchrzak <tomasz.majchrzak@intel.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-10-12badblocks: fix overlapping check for clearingTomasz Majchrzak
Current bad block clear implementation assumes the range to clear overlaps with at least one bad block already stored. If given range to clear precedes first bad block in a list, the first entry is incorrectly updated. Check not only if stored block end is past clear block end but also if stored block start is before clear block end. Signed-off-by: Tomasz Majchrzak <tomasz.majchrzak@intel.com> Acked-by: NeilBrown <neilb@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-01-09block, badblocks: introduce devm_init_badblocksDan Williams
Provide a devres interface for initializing a badblocks instance. The pmem driver has several scenarios where it will be beneficial to have this structure automatically freed when the device is disabled / fails probe. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-01-09block: clarify badblocks lifetimeDan Williams
The badblocks list attached to a gendisk is allocated by the driver which equates to the driver owning the lifetime of the object. Do not automatically free it in del_gendisk(). This is in preparation for expanding the use of badblocks in libnvdimm drivers and introducing devm_init_badblocks(). Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-01-09badblocks: rename badblocks_free to badblocks_exitDan Williams
For symmetry with badblocks_init() make it clear that this path only destroys incremental allocations of a badblocks instance, and does not free the badblocks instance itself. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-01-09badblocks: Add core badblock management codeVishal Verma
Take the core badblocks implementation from md, and make it generally available. This follows the same style as kernel implementations of linked lists, rb-trees etc, where you can have a structure that can be embedded anywhere, and accessor functions to manipulate the data. The only changes in this copy of the code are ones to generalize function/variable names from md-specific ones. Also add init and free functions. Signed-off-by: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>