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path: root/drivers/md/bcache/sysfs.c
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2023-12-08bcache: prevent potential division by zero errorRand Deeb
commit 2c7f497ac274a14330208b18f6f734000868ebf9 upstream. In SHOW(), the variable 'n' is of type 'size_t.' While there is a conditional check to verify that 'n' is not equal to zero before executing the 'do_div' macro, concerns arise regarding potential division by zero error in 64-bit environments. The concern arises when 'n' is 64 bits in size, greater than zero, and the lower 32 bits of it are zeros. In such cases, the conditional check passes because 'n' is non-zero, but the 'do_div' macro casts 'n' to 'uint32_t,' effectively truncating it to its lower 32 bits. Consequently, the 'n' value becomes zero. To fix this potential division by zero error and ensure precise division handling, this commit replaces the 'do_div' macro with div64_u64(). div64_u64() is designed to work with 64-bit operands, guaranteeing that division is performed correctly. This change enhances the robustness of the code, ensuring that division operations yield accurate results in all scenarios, eliminating the possibility of division by zero, and improving compatibility across different 64-bit environments. Found by Linux Verification Center (linuxtesting.org) with SVACE. Signed-off-by: Rand Deeb <rand.sec96@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Coly Li <colyli@suse.de> Link: https://lore.kernel.org/r/20231120052503.6122-5-colyli@suse.de Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11bcache: add readahead cache policy options via sysfs interfaceColy Li
commit 038ba8cc1bffc51250add4a9b9249d4331576d8f upstream. In year 2007 high performance SSD was still expensive, in order to save more space for real workload or meta data, the readahead I/Os for non-meta data was bypassed and not cached on SSD. In now days, SSD price drops a lot and people can find larger size SSD with more comfortable price. It is unncessary to alway bypass normal readahead I/Os to save SSD space for now. This patch adds options for readahead data cache policies via sysfs file /sys/block/bcache<N>/readahead_cache_policy, the options are, - "all": cache all readahead data I/Os. - "meta-only": only cache meta data, and bypass other regular I/Os. If users want to make bcache continue to only cache readahead request for metadata and bypass regular data readahead, please set "meta-only" to this sysfs file. By default, bcache will back to cache all read- ahead requests now. Cc: stable@vger.kernel.org Signed-off-by: Coly Li <colyli@suse.de> Acked-by: Eric Wheeler <bcache@linux.ewheeler.net> Cc: Michael Lyle <mlyle@lyle.org> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-06bcache: fix input overflow to writeback_rate_minimumColy Li
[ Upstream commit dab71b2db98dcdd4657d151b01a7be88ce10f9d1 ] dc->writeback_rate_minimum is type unsigned integer variable, it is set via sysfs interface, and converte from input string to unsigned integer by d_strtoul_nonzero(). When the converted input value is larger than UINT_MAX, overflow to unsigned integer happens. This patch fixes the overflow by using sysfs_strotoul_clamp() to convert input string and limit the value in range [1, UINT_MAX], then the overflow can be avoided. Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-07-26bcache: fix mistaken sysfs entry for io_error counterColy Li
commit 5461999848e0462c14f306a62923d22de820a59c upstream. In bch_cached_dev_files[] from driver/md/bcache/sysfs.c, sysfs_errors is incorrectly inserted in. The correct entry should be sysfs_io_errors. This patch fixes the problem and now I/O errors of cached device can be read from /sys/block/bcache<N>/bcache/io_errors. Fixes: c7b7bd07404c5 ("bcache: add io_disable to struct cached_dev") Signed-off-by: Coly Li <colyli@suse.de> Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-19bcache: only set BCACHE_DEV_WB_RUNNING when cached device attachedColy Li
commit 1f0ffa67349c56ea54c03ccfd1e073c990e7411e upstream. When people set a writeback percent via sysfs file, /sys/block/bcache<N>/bcache/writeback_percent current code directly sets BCACHE_DEV_WB_RUNNING to dc->disk.flags and schedules kworker dc->writeback_rate_update. If there is no cache set attached to, the writeback kernel thread is not running indeed, running dc->writeback_rate_update does not make sense and may cause NULL pointer deference when reference cache set pointer inside update_writeback_rate(). This patch checks whether the cache set point (dc->disk.c) is NULL in sysfs interface handler, and only set BCACHE_DEV_WB_RUNNING and schedule dc->writeback_rate_update when dc->disk.c is not NULL (it means the cache device is attached to a cache set). This problem might be introduced from initial bcache commit, but commit 3fd47bfe55b0 ("bcache: stop dc->writeback_rate_update properly") changes part of the original code piece, so I add 'Fixes: 3fd47bfe55b0' to indicate from which commit this patch can be applied. Fixes: 3fd47bfe55b0 ("bcache: stop dc->writeback_rate_update properly") Reported-by: Bjørn Forsman <bjorn.forsman@gmail.com> Signed-off-by: Coly Li <colyli@suse.de> Reviewed-by: Bjørn Forsman <bjorn.forsman@gmail.com> Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-05bcache: fix potential div-zero error of writeback_rate_p_term_inverseColy Li
[ Upstream commit 5b5fd3c94eef69dcfaa8648198e54c92e5687d6d ] Current code already uses d_strtoul_nonzero() to convert input string to an unsigned integer, to make sure writeback_rate_p_term_inverse won't be zero value. But overflow may happen when converting input string to an unsigned integer value by d_strtoul_nonzero(), then dc->writeback_rate_p_term_inverse can still be set to 0 even if the sysfs file input value is not zero, e.g. 4294967296 (a.k.a UINT_MAX+1). If dc->writeback_rate_p_term_inverse is set to 0, it might cause a dev-zero error in following code from __update_writeback_rate(), int64_t proportional_scaled = div_s64(error, dc->writeback_rate_p_term_inverse); This patch replaces d_strtoul_nonzero() by sysfs_strtoul_clamp() and limit the value range in [1, UINT_MAX]. Then the unsigned integer overflow and dev-zero error can be avoided. Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-04-05bcache: fix potential div-zero error of writeback_rate_i_term_inverseColy Li
[ Upstream commit c3b75a2199cdbfc1c335155fe143d842604b1baa ] dc->writeback_rate_i_term_inverse can be set via sysfs interface. It is in type unsigned int, and convert from input string by d_strtoul(). The problem is d_strtoul() does not check valid range of the input, if 4294967296 is written into sysfs file writeback_rate_i_term_inverse, an overflow of unsigned integer will happen and value 0 is set to dc->writeback_rate_i_term_inverse. In writeback.c:__update_writeback_rate(), there are following lines of code, integral_scaled = div_s64(dc->writeback_rate_integral, dc->writeback_rate_i_term_inverse); If dc->writeback_rate_i_term_inverse is set to 0 via sysfs interface, a div-zero error might be triggered in the above code. Therefore we need to add a range limitation in the sysfs interface, this is what this patch does, use sysfs_stroul_clamp() to replace d_strtoul() and restrict the input range in [1, UINT_MAX]. Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-04-05bcache: fix input overflow to sequential_cutoffColy Li
[ Upstream commit 8c27a3953e92eb0b22dbb03d599f543a05f9574e ] People may set sequential_cutoff of a cached device via sysfs file, but current code does not check input value overflow. E.g. if value 4294967295 (UINT_MAX) is written to file sequential_cutoff, its value is 4GB, but if 4294967296 (UINT_MAX + 1) is written into, its value will be 0. This is an unexpected behavior. This patch replaces d_strtoi_h() by sysfs_strtoul_clamp() to convert input string to unsigned integer value, and limit its range in [0, UINT_MAX]. Then the input overflow can be fixed. Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-04-05bcache: fix input overflow to cache set sysfs file io_error_halflifeColy Li
[ Upstream commit a91fbda49f746119828f7e8ad0f0aa2ab0578f65 ] Cache set sysfs entry io_error_halflife is used to set c->error_decay. c->error_decay is in type unsigned int, and it is converted by strtoul_or_return(), therefore overflow to c->error_decay is possible for a large input value. This patch fixes the overflow by using strtoul_safe_clamp() to convert input string to an unsigned long value in range [0, UINT_MAX], then divides by 88 and set it to c->error_decay. Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2018-11-13bcache: Populate writeback_rate_minimum attributeBen Peddell
[ Upstream commit 7567c2a2ad9e80a2ce977eef535e64b61899633e ] Forgot to include the maintainers with my first email. Somewhere between Michael Lyle's original "bcache: PI controller for writeback rate V2" patch dated 07 Sep 2017 and 1d316e6 bcache: implement PI controller for writeback rate, the mapping of the writeback_rate_minimum attribute was dropped. Re-add the missing sysfs writeback_rate_minimum attribute mapping to "allow the user to specify a minimum rate at which dirty blocks are retired." Fixes: 1d316e6 ("bcache: implement PI controller for writeback rate") Signed-off-by: Ben Peddell <klightspeed@killerwolves.net> Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-11bcache: add static const prefix to char * array declarationsColy Li
This patch declares char * array with const prefix in sysfs.c, which is suggested by checkpatch.pl. Signed-off-by: Coly Li <colyli@suse.de> Reviewed-by: Shenghui Wang <shhuiw@foxmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-08-11bcache: style fixes for lines over 80 charactersColy Li
This patch fixes the lines over 80 characters into more lines, to minimize warnings by checkpatch.pl. There are still some lines exceed 80 characters, but it is better to be a single line and I don't change them. Signed-off-by: Coly Li <colyli@suse.de> Reviewed-by: Shenghui Wang <shhuiw@foxmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-08-11bcache: style fix to add a blank line after declarationsColy Li
Signed-off-by: Coly Li <colyli@suse.de> Reviewed-by: Shenghui Wang <shhuiw@foxmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-08-11bcache: style fix to replace 'unsigned' by 'unsigned int'Coly Li
This patch fixes warning reported by checkpatch.pl by replacing 'unsigned' with 'unsigned int'. Signed-off-by: Coly Li <colyli@suse.de> Reviewed-by: Shenghui Wang <shhuiw@foxmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-08-10bcache: fix error setting writeback_rate through sysfs interfaceColy Li
Commit ea8c5356d390 ("bcache: set max writeback rate when I/O request is idle") changes struct bch_ratelimit member rate from uint32_t to atomic_long_t and uses atomic_long_set() in drivers/md/bcache/sysfs.c to set new writeback rate, after the input is converted from memory buf to long int by sysfs_strtoul_clamp(). The above change has a problem because there is an implicit return inside sysfs_strtoul_clamp() so the following atomic_long_set() won't be called. This error is detected by 0day system with following snipped smatch warnings: drivers/md/bcache/sysfs.c:271 __cached_dev_store() error: uninitialized symbol 'v'. 270 sysfs_strtoul_clamp(writeback_rate, v, 1, INT_MAX); ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ @271 atomic_long_set(&dc->writeback_rate.rate, v); This patch fixes the above error by using strtoul_safe_clamp() to convert the input buffer into a long int type result. Fixes: ea8c5356d390 ("bcache: set max writeback rate when I/O request is idle") Cc: Kai Krakow <kai@kaishome.de> Cc: Stefan Priebe <s.priebe@profihost.ag> Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-08-09bcache: make the pr_err statement used for ENOENT only in sysfs_attatch sectionShenghui Wang
The pr_err statement in the code for sysfs_attatch section would run for various error codes, which maybe confusing. E.g, Run the command twice: echo 796b5c05-b03c-4bc7-9cbd-a8df5e8be891 > \ /sys/block/bcache0/bcache/attach [the backing dev got attached on the first run] echo 796b5c05-b03c-4bc7-9cbd-a8df5e8be891 > \ /sys/block/bcache0/bcache/attach In dmesg, after the command run twice, we can get: bcache: bch_cached_dev_attach() Can't attach sda6: already attached bcache: __cached_dev_store() Can't attach 796b5c05-b03c-4bc7-9cbd-\ a8df5e8be891 : cache set not found The first statement in the message was right, but the second was confusing. bch_cached_dev_attach has various pr_ statements for various error codes, except ENOENT. After the change, rerun above command twice: echo 796b5c05-b03c-4bc7-9cbd-a8df5e8be891 > \ /sys/block/bcache0/bcache/attach echo 796b5c05-b03c-4bc7-9cbd-a8df5e8be891 > \ /sys/block/bcache0/bcache/attach In dmesg we only got: bcache: bch_cached_dev_attach() Can't attach sda6: already attached No confusing "cache set not found" message anymore. And for some not exist SET-UUID: echo 796b5c05-b03c-4bc7-9cbd-a8df5e8be898 > \ /sys/block/bcache0/bcache/attach In dmesg we can get: bcache: __cached_dev_store() Can't attach 796b5c05-b03c-4bc7-9cbd-\ a8df5e8be898 : cache set not found Signed-off-by: Shenghui Wang <shhuiw@foxmail.com> Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-08-09bcache: set max writeback rate when I/O request is idleColy Li
Commit b1092c9af9ed ("bcache: allow quick writeback when backing idle") allows the writeback rate to be faster if there is no I/O request on a bcache device. It works well if there is only one bcache device attached to the cache set. If there are many bcache devices attached to a cache set, it may introduce performance regression because multiple faster writeback threads of the idle bcache devices will compete the btree level locks with the bcache device who have I/O requests coming. This patch fixes the above issue by only permitting fast writebac when all bcache devices attached on the cache set are idle. And if one of the bcache devices has new I/O request coming, minimized all writeback throughput immediately and let PI controller __update_writeback_rate() to decide the upcoming writeback rate for each bcache device. Also when all bcache devices are idle, limited wrieback rate to a small number is wast of thoughput, especially when backing devices are slower non-rotation devices (e.g. SATA SSD). This patch sets a max writeback rate for each backing device if the whole cache set is idle. A faster writeback rate in idle time means new I/Os may have more available space for dirty data, and people may observe a better write performance then. Please note bcache may change its cache mode in run time, and this patch still works if the cache mode is switched from writeback mode and there is still dirty data on cache. Fixes: Commit b1092c9af9ed ("bcache: allow quick writeback when backing idle") Cc: stable@vger.kernel.org #4.16+ Signed-off-by: Coly Li <colyli@suse.de> Tested-by: Kai Krakow <kai@kaishome.de> Tested-by: Stefan Priebe <s.priebe@profihost.ag> Cc: Michael Lyle <mlyle@lyle.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-08-09bcache: display rate debug parameters to 0 when writeback is not runningColy Li
When writeback is not running, writeback rate should be 0, other value is misleading. And the following dyanmic writeback rate debug parameters should be 0 too, rate, proportional, integral, change otherwise they are misleading when writeback is not running. Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-06-12treewide: Use array_size() in vmalloc()Kees Cook
The vmalloc() function has no 2-factor argument form, so multiplication factors need to be wrapped in array_size(). This patch replaces cases of: vmalloc(a * b) with: vmalloc(array_size(a, b)) as well as handling cases of: vmalloc(a * b * c) with: vmalloc(array3_size(a, b, c)) This does, however, attempt to ignore constant size factors like: vmalloc(4 * 1024) though any constants defined via macros get caught up in the conversion. Any factors with a sizeof() of "unsigned char", "char", and "u8" were dropped, since they're redundant. The Coccinelle script used for this was: // Fix redundant parens around sizeof(). @@ type TYPE; expression THING, E; @@ ( vmalloc( - (sizeof(TYPE)) * E + sizeof(TYPE) * E , ...) | vmalloc( - (sizeof(THING)) * E + sizeof(THING) * E , ...) ) // Drop single-byte sizes and redundant parens. @@ expression COUNT; typedef u8; typedef __u8; @@ ( vmalloc( - sizeof(u8) * (COUNT) + COUNT , ...) | vmalloc( - sizeof(__u8) * (COUNT) + COUNT , ...) | vmalloc( - sizeof(char) * (COUNT) + COUNT , ...) | vmalloc( - sizeof(unsigned char) * (COUNT) + COUNT , ...) | vmalloc( - sizeof(u8) * COUNT + COUNT , ...) | vmalloc( - sizeof(__u8) * COUNT + COUNT , ...) | vmalloc( - sizeof(char) * COUNT + COUNT , ...) | vmalloc( - sizeof(unsigned char) * COUNT + COUNT , ...) ) // 2-factor product with sizeof(type/expression) and identifier or constant. @@ type TYPE; expression THING; identifier COUNT_ID; constant COUNT_CONST; @@ ( vmalloc( - sizeof(TYPE) * (COUNT_ID) + array_size(COUNT_ID, sizeof(TYPE)) , ...) | vmalloc( - sizeof(TYPE) * COUNT_ID + array_size(COUNT_ID, sizeof(TYPE)) , ...) | vmalloc( - sizeof(TYPE) * (COUNT_CONST) + array_size(COUNT_CONST, sizeof(TYPE)) , ...) | vmalloc( - sizeof(TYPE) * COUNT_CONST + array_size(COUNT_CONST, sizeof(TYPE)) , ...) | vmalloc( - sizeof(THING) * (COUNT_ID) + array_size(COUNT_ID, sizeof(THING)) , ...) | vmalloc( - sizeof(THING) * COUNT_ID + array_size(COUNT_ID, sizeof(THING)) , ...) | vmalloc( - sizeof(THING) * (COUNT_CONST) + array_size(COUNT_CONST, sizeof(THING)) , ...) | vmalloc( - sizeof(THING) * COUNT_CONST + array_size(COUNT_CONST, sizeof(THING)) , ...) ) // 2-factor product, only identifiers. @@ identifier SIZE, COUNT; @@ vmalloc( - SIZE * COUNT + array_size(COUNT, SIZE) , ...) // 3-factor product with 1 sizeof(type) or sizeof(expression), with // redundant parens removed. @@ expression THING; identifier STRIDE, COUNT; type TYPE; @@ ( vmalloc( - sizeof(TYPE) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | vmalloc( - sizeof(TYPE) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | vmalloc( - sizeof(TYPE) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | vmalloc( - sizeof(TYPE) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | vmalloc( - sizeof(THING) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | vmalloc( - sizeof(THING) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | vmalloc( - sizeof(THING) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | vmalloc( - sizeof(THING) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) ) // 3-factor product with 2 sizeof(variable), with redundant parens removed. @@ expression THING1, THING2; identifier COUNT; type TYPE1, TYPE2; @@ ( vmalloc( - sizeof(TYPE1) * sizeof(TYPE2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | vmalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | vmalloc( - sizeof(THING1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | vmalloc( - sizeof(THING1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | vmalloc( - sizeof(TYPE1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) | vmalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) ) // 3-factor product, only identifiers, with redundant parens removed. @@ identifier STRIDE, SIZE, COUNT; @@ ( vmalloc( - (COUNT) * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | vmalloc( - COUNT * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | vmalloc( - COUNT * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | vmalloc( - (COUNT) * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | vmalloc( - COUNT * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | vmalloc( - (COUNT) * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | vmalloc( - (COUNT) * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | vmalloc( - COUNT * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) ) // Any remaining multi-factor products, first at least 3-factor products // when they're not all constants... @@ expression E1, E2, E3; constant C1, C2, C3; @@ ( vmalloc(C1 * C2 * C3, ...) | vmalloc( - E1 * E2 * E3 + array3_size(E1, E2, E3) , ...) ) // And then all remaining 2 factors products when they're not all constants. @@ expression E1, E2; constant C1, C2; @@ ( vmalloc(C1 * C2, ...) | vmalloc( - E1 * E2 + array_size(E1, E2) , ...) ) Signed-off-by: Kees Cook <keescook@chromium.org>
2018-05-28bcache: Replace bch_read_string_list() by __sysfs_match_string()Andy Shevchenko
Kernel library has a common function to match user input from sysfs against an array of strings. Thus, replace bch_read_string_list() by __sysfs_match_string(). Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-05-28bcache: Move couple of functions to sysfs.cAndy Shevchenko
There is couple of functions that are used exclusively in sysfs.c. Move it to there and make them static. Besides above, it will allow further clean up. No functional change intended. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-05-28bcache: Move couple of string arrays to sysfs.cAndy Shevchenko
There is couple of string arrays that are used exclusively in sysfs.c. Move it to there and make them static. Besides above, it will allow further clean up. No functional change intended. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-03-18bcache: add io_disable to struct cached_devColy Li
If a bcache device is configured to writeback mode, current code does not handle write I/O errors on backing devices properly. In writeback mode, write request is written to cache device, and latter being flushed to backing device. If I/O failed when writing from cache device to the backing device, bcache code just ignores the error and upper layer code is NOT noticed that the backing device is broken. This patch tries to handle backing device failure like how the cache device failure is handled, - Add a error counter 'io_errors' and error limit 'error_limit' in struct cached_dev. Add another io_disable to struct cached_dev to disable I/Os on the problematic backing device. - When I/O error happens on backing device, increase io_errors counter. And if io_errors reaches error_limit, set cache_dev->io_disable to true, and stop the bcache device. The result is, if backing device is broken of disconnected, and I/O errors reach its error limit, backing device will be disabled and the associated bcache device will be removed from system. Changelog: v2: remove "bcache: " prefix in pr_error(), and use correct name string to print out bcache device gendisk name. v1: indeed this is new added in v2 patch set. Signed-off-by: Coly Li <colyli@suse.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Michael Lyle <mlyle@lyle.org> Cc: Michael Lyle <mlyle@lyle.org> Cc: Junhui Tang <tang.junhui@zte.com.cn> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-03-18bcache: fix incorrect sysfs output value of strip sizeTang Junhui
Stripe size is shown as zero when no strip in back end device: [root@ceph132 ~]# cat /sys/block/sdd/bcache/stripe_size 0.0k Actually it should be 1T Bytes (1 << 31 sectors), but in sysfs interface, stripe_size was changed from sectors to bytes, and move 9 bits left, so the 32 bits variable overflows. This patch change the variable to a 64 bits type before moving bits. Signed-off-by: Tang Junhui <tang.junhui@zte.com.cn> Reviewed-by: Michael Lyle <mlyle@lyle.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-03-18bcache: add stop_when_cache_set_failed option to backing deviceColy Li
When there are too many I/O errors on cache device, current bcache code will retire the whole cache set, and detach all bcache devices. But the detached bcache devices are not stopped, which is problematic when bcache is in writeback mode. If the retired cache set has dirty data of backing devices, continue writing to bcache device will write to backing device directly. If the LBA of write request has a dirty version cached on cache device, next time when the cache device is re-registered and backing device re-attached to it again, the stale dirty data on cache device will be written to backing device, and overwrite latest directly written data. This situation causes a quite data corruption. But we cannot simply stop all attached bcache devices when the cache set is broken or disconnected. For example, use bcache to accelerate performance of an email service. In such workload, if cache device is broken but no dirty data lost, keep the bcache device alive and permit email service continue to access user data might be a better solution for the cache device failure. Nix <nix@esperi.org.uk> points out the issue and provides the above example to explain why it might be necessary to not stop bcache device for broken cache device. Pavel Goran <via-bcache@pvgoran.name> provides a brilliant suggestion to provide "always" and "auto" options to per-cached device sysfs file stop_when_cache_set_failed. If cache set is retiring and the backing device has no dirty data on cache, it should be safe to keep the bcache device alive. In this case, if stop_when_cache_set_failed is set to "auto", the device failure handling code will not stop this bcache device and permit application to access the backing device with a unattached bcache device. Changelog: [mlyle: edited to not break string constants across lines] v3: fix typos pointed out by Nix. v2: change option values of stop_when_cache_set_failed from 1/0 to "auto"/"always". v1: initial version, stop_when_cache_set_failed can be 0 (not stop) or 1 (always stop). Signed-off-by: Coly Li <colyli@suse.de> Reviewed-by: Michael Lyle <mlyle@lyle.org> Signed-off-by: Michael Lyle <mlyle@lyle.org> Cc: Nix <nix@esperi.org.uk> Cc: Pavel Goran <via-bcache@pvgoran.name> Cc: Junhui Tang <tang.junhui@zte.com.cn> Cc: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-03-18bcache: add CACHE_SET_IO_DISABLE to struct cache_set flagsColy Li
When too many I/Os failed on cache device, bch_cache_set_error() is called in the error handling code path to retire whole problematic cache set. If new I/O requests continue to come and take refcount dc->count, the cache set won't be retired immediately, this is a problem. Further more, there are several kernel thread and self-armed kernel work may still running after bch_cache_set_error() is called. It needs to wait quite a while for them to stop, or they won't stop at all. They also prevent the cache set from being retired. The solution in this patch is, to add per cache set flag to disable I/O request on this cache and all attached backing devices. Then new coming I/O requests can be rejected in *_make_request() before taking refcount, kernel threads and self-armed kernel worker can stop very fast when flags bit CACHE_SET_IO_DISABLE is set. Because bcache also do internal I/Os for writeback, garbage collection, bucket allocation, journaling, this kind of I/O should be disabled after bch_cache_set_error() is called. So closure_bio_submit() is modified to check whether CACHE_SET_IO_DISABLE is set on cache_set->flags. If set, closure_bio_submit() will set bio->bi_status to BLK_STS_IOERR and return, generic_make_request() won't be called. A sysfs interface is also added to set or clear CACHE_SET_IO_DISABLE bit from cache_set->flags, to disable or enable cache set I/O for debugging. It is helpful to trigger more corner case issues for failed cache device. Changelog v4, add wait_for_kthread_stop(), and call it before exits writeback and gc kernel threads. v3, change CACHE_SET_IO_DISABLE from 4 to 3, since it is bit index. remove "bcache: " prefix when printing out kernel message. v2, more changes by previous review, - Use CACHE_SET_IO_DISABLE of cache_set->flags, suggested by Junhui. - Check CACHE_SET_IO_DISABLE in bch_btree_gc() to stop a while-loop, this is reported and inspired from origal patch of Pavel Vazharov. v1, initial version. Signed-off-by: Coly Li <colyli@suse.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Michael Lyle <mlyle@lyle.org> Cc: Junhui Tang <tang.junhui@zte.com.cn> Cc: Michael Lyle <mlyle@lyle.org> Cc: Pavel Vazharov <freakpv@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-03-18bcache: stop dc->writeback_rate_update properlyColy Li
struct delayed_work writeback_rate_update in struct cache_dev is a delayed worker to call function update_writeback_rate() in period (the interval is defined by dc->writeback_rate_update_seconds). When a metadate I/O error happens on cache device, bcache error handling routine bch_cache_set_error() will call bch_cache_set_unregister() to retire whole cache set. On the unregister code path, this delayed work is stopped by calling cancel_delayed_work_sync(&dc->writeback_rate_update). dc->writeback_rate_update is a special delayed work from others in bcache. In its routine update_writeback_rate(), this delayed work is re-armed itself. That means when cancel_delayed_work_sync() returns, this delayed work can still be executed after several seconds defined by dc->writeback_rate_update_seconds. The problem is, after cancel_delayed_work_sync() returns, the cache set unregister code path will continue and release memory of struct cache set. Then the delayed work is scheduled to run, __update_writeback_rate() will reference the already released cache_set memory, and trigger a NULL pointer deference fault. This patch introduces two more bcache device flags, - BCACHE_DEV_WB_RUNNING bit set: bcache device is in writeback mode and running, it is OK for dc->writeback_rate_update to re-arm itself. bit clear:bcache device is trying to stop dc->writeback_rate_update, this delayed work should not re-arm itself and quit. - BCACHE_DEV_RATE_DW_RUNNING bit set: routine update_writeback_rate() is executing. bit clear: routine update_writeback_rate() quits. This patch also adds a function cancel_writeback_rate_update_dwork() to wait for dc->writeback_rate_update quits before cancel it by calling cancel_delayed_work_sync(). In order to avoid a deadlock by unexpected quit dc->writeback_rate_update, after time_out seconds this function will give up and continue to call cancel_delayed_work_sync(). And here I explain how this patch stops self re-armed delayed work properly with the above stuffs. update_writeback_rate() sets BCACHE_DEV_RATE_DW_RUNNING at its beginning and clears BCACHE_DEV_RATE_DW_RUNNING at its end. Before calling cancel_writeback_rate_update_dwork() clear flag BCACHE_DEV_WB_RUNNING. Before calling cancel_delayed_work_sync() wait utill flag BCACHE_DEV_RATE_DW_RUNNING is clear. So when calling cancel_delayed_work_sync(), dc->writeback_rate_update must be already re- armed, or quite by seeing BCACHE_DEV_WB_RUNNING cleared. In both cases delayed work routine update_writeback_rate() won't be executed after cancel_delayed_work_sync() returns. Inside update_writeback_rate() before calling schedule_delayed_work(), flag BCACHE_DEV_WB_RUNNING is checked before. If this flag is cleared, it means someone is about to stop the delayed work. Because flag BCACHE_DEV_RATE_DW_RUNNING is set already and cancel_delayed_work_sync() has to wait for this flag to be cleared, we don't need to worry about race condition here. If update_writeback_rate() is scheduled to run after checking BCACHE_DEV_RATE_DW_RUNNING and before calling cancel_delayed_work_sync() in cancel_writeback_rate_update_dwork(), it is also safe. Because at this moment BCACHE_DEV_WB_RUNNING is cleared with memory barrier. As I mentioned previously, update_writeback_rate() will see BCACHE_DEV_WB_RUNNING is clear and quit immediately. Because there are more dependences inside update_writeback_rate() to struct cache_set memory, dc->writeback_rate_update is not a simple self re-arm delayed work. After trying many different methods (e.g. hold dc->count, or use locks), this is the only way I can find which works to properly stop dc->writeback_rate_update delayed work. Changelog: v3: change values of BCACHE_DEV_WB_RUNNING and BCACHE_DEV_RATE_DW_RUNNING to bit index, for test_bit(). v2: Try to fix the race issue which is pointed out by Junhui. v1: The initial version for review Signed-off-by: Coly Li <colyli@suse.de> Reviewed-by: Junhui Tang <tang.junhui@zte.com.cn> Reviewed-by: Michael Lyle <mlyle@lyle.org> Cc: Michael Lyle <mlyle@lyle.org> Cc: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-02-07bcache: fix for data collapse after re-attaching an attached deviceTang Junhui
back-end device sdm has already attached a cache_set with ID f67ebe1f-f8bc-4d73-bfe5-9dc88607f119, then try to attach with another cache set, and it returns with an error: [root]# cd /sys/block/sdm/bcache [root]# echo 5ccd0a63-148e-48b8-afa2-aca9cbd6279f > attach -bash: echo: write error: Invalid argument After that, execute a command to modify the label of bcache device: [root]# echo data_disk1 > label Then we reboot the system, when the system power on, the back-end device can not attach to cache_set, a messages show in the log: Feb 5 12:05:52 ceph152 kernel: [922385.508498] bcache: bch_cached_dev_attach() couldn't find uuid for sdm in set In sysfs_attach(), dc->sb.set_uuid was assigned to the value which input through sysfs, no matter whether it is success or not in bch_cached_dev_attach(). For example, If the back-end device has already attached to an cache set, bch_cached_dev_attach() would fail, but dc->sb.set_uuid was changed. Then modify the label of bcache device, it will call bch_write_bdev_super(), which would write the dc->sb.set_uuid to the super block, so we record a wrong cache set ID in the super block, after the system reboot, the cache set couldn't find the uuid of the back-end device, so the bcache device couldn't exist and use any more. In this patch, we don't assigned cache set ID to dc->sb.set_uuid in sysfs_attach() directly, but input it into bch_cached_dev_attach(), and assigned dc->sb.set_uuid to the cache set ID after the back-end device attached to the cache set successful. Signed-off-by: Tang Junhui <tang.junhui@zte.com.cn> Reviewed-by: Michael Lyle <mlyle@lyle.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-02-07bcache: return attach error when no cache set existTang Junhui
I attach a back-end device to a cache set, and the cache set is not registered yet, this back-end device did not attach successfully, and no error returned: [root]# echo 87859280-fec6-4bcc-20df7ca8f86b > /sys/block/sde/bcache/attach [root]# In sysfs_attach(), the return value "v" is initialized to "size" in the beginning, and if no cache set exist in bch_cache_sets, the "v" value would not change any more, and return to sysfs, sysfs regard it as success since the "size" is a positive number. This patch fixes this issue by assigning "v" with "-ENOENT" in the initialization. Signed-off-by: Tang Junhui <tang.junhui@zte.com.cn> Reviewed-by: Michael Lyle <mlyle@lyle.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-02-07bcache: set writeback_rate_update_seconds in range [1, 60] secondsColy Li
dc->writeback_rate_update_seconds can be set via sysfs and its value can be set to [1, ULONG_MAX]. It does not make sense to set such a large value, 60 seconds is long enough value considering the default 5 seconds works well for long time. Because dc->writeback_rate_update is a special delayed work, it re-arms itself inside the delayed work routine update_writeback_rate(). When stopping it by cancel_delayed_work_sync(), there should be a timeout to wait and make sure the re-armed delayed work is stopped too. A small max value of dc->writeback_rate_update_seconds is also helpful to decide a reasonable small timeout. This patch limits sysfs interface to set dc->writeback_rate_update_seconds in range of [1, 60] seconds, and replaces the hand-coded number by macros. Changelog: v2: fix a rebase typo in v4, which is pointed out by Michael Lyle. v1: initial version. Signed-off-by: Coly Li <colyli@suse.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Michael Lyle <mlyle@lyle.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-02-07bcache: set error_limit correctlyColy Li
Struct cache uses io_errors for two purposes, - Error decay: when cache set error_decay is set, io_errors is used to generate a small piece of delay when I/O error happens. - I/O errors counter: in order to generate big enough value for error decay, I/O errors counter value is stored by left shifting 20 bits (a.k.a IO_ERROR_SHIFT). In function bch_count_io_errors(), if I/O errors counter reaches cache set error limit, bch_cache_set_error() will be called to retire the whold cache set. But current code is problematic when checking the error limit, see the following code piece from bch_count_io_errors(), 90 if (error) { 91 char buf[BDEVNAME_SIZE]; 92 unsigned errors = atomic_add_return(1 << IO_ERROR_SHIFT, 93 &ca->io_errors); 94 errors >>= IO_ERROR_SHIFT; 95 96 if (errors < ca->set->error_limit) 97 pr_err("%s: IO error on %s, recovering", 98 bdevname(ca->bdev, buf), m); 99 else 100 bch_cache_set_error(ca->set, 101 "%s: too many IO errors %s", 102 bdevname(ca->bdev, buf), m); 103 } At line 94, errors is right shifting IO_ERROR_SHIFT bits, now it is real errors counter to compare at line 96. But ca->set->error_limit is initia- lized with an amplified value in bch_cache_set_alloc(), 1545 c->error_limit = 8 << IO_ERROR_SHIFT; It means by default, in bch_count_io_errors(), before 8<<20 errors happened bch_cache_set_error() won't be called to retire the problematic cache device. If the average request size is 64KB, it means bcache won't handle failed device until 512GB data is requested. This is too large to be an I/O threashold. So I believe the correct error limit should be much less. This patch sets default cache set error limit to 8, then in bch_count_io_errors() when errors counter reaches 8 (if it is default value), function bch_cache_set_error() will be called to retire the whole cache set. This patch also removes bits shifting when store or show io_error_limit value via sysfs interface. Nowadays most of SSDs handle internal flash failure automatically by LBA address re-indirect mapping. If an I/O error can be observed by upper layer code, it will be a notable error because that SSD can not re-indirect map the problematic LBA address to an available flash block. This situation indicates the whole SSD will be failed very soon. Therefore setting 8 as the default io error limit value makes sense, it is enough for most of cache devices. Changelog: v2: add reviewed-by from Hannes. v1: initial version for review. Signed-off-by: Coly Li <colyli@suse.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Tang Junhui <tang.junhui@zte.com.cn> Reviewed-by: Michael Lyle <mlyle@lyle.org> Cc: Junhui Tang <tang.junhui@zte.com.cn> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-02-07bcache: add journal statisticTang Junhui
Sometimes, Journal takes up a lot of CPU, we need statistics to know what's the journal is doing. So this patch provide some journal statistics: 1) reclaim: how many times the journal try to reclaim resource, usually the journal bucket or/and the pin are exhausted. 2) flush_write: how many times the journal try to flush btree node to cache device, usually the journal bucket are exhausted. 3) retry_flush_write: how many times the journal retry to flush the next btree node, usually the previous tree node have been flushed by other thread. we show these statistic by sysfs interface. Through these statistics We can totally see the status of journal module when the CPU is too high. Signed-off-by: Tang Junhui <tang.junhui@zte.com.cn> Reviewed-by: Michael Lyle <mlyle@lyle.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-14Merge branch 'for-4.15/block' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull core block layer updates from Jens Axboe: "This is the main pull request for block storage for 4.15-rc1. Nothing out of the ordinary in here, and no API changes or anything like that. Just various new features for drivers, core changes, etc. In particular, this pull request contains: - A patch series from Bart, closing the whole on blk/scsi-mq queue quescing. - A series from Christoph, building towards hidden gendisks (for multipath) and ability to move bio chains around. - NVMe - Support for native multipath for NVMe (Christoph). - Userspace notifications for AENs (Keith). - Command side-effects support (Keith). - SGL support (Chaitanya Kulkarni) - FC fixes and improvements (James Smart) - Lots of fixes and tweaks (Various) - bcache - New maintainer (Michael Lyle) - Writeback control improvements (Michael) - Various fixes (Coly, Elena, Eric, Liang, et al) - lightnvm updates, mostly centered around the pblk interface (Javier, Hans, and Rakesh). - Removal of unused bio/bvec kmap atomic interfaces (me, Christoph) - Writeback series that fix the much discussed hundreds of millions of sync-all units. This goes all the way, as discussed previously (me). - Fix for missing wakeup on writeback timer adjustments (Yafang Shao). - Fix laptop mode on blk-mq (me). - {mq,name} tupple lookup for IO schedulers, allowing us to have alias names. This means you can use 'deadline' on both !mq and on mq (where it's called mq-deadline). (me). - blktrace race fix, oopsing on sg load (me). - blk-mq optimizations (me). - Obscure waitqueue race fix for kyber (Omar). - NBD fixes (Josef). - Disable writeback throttling by default on bfq, like we do on cfq (Luca Miccio). - Series from Ming that enable us to treat flush requests on blk-mq like any other request. This is a really nice cleanup. - Series from Ming that improves merging on blk-mq with schedulers, getting us closer to flipping the switch on scsi-mq again. - BFQ updates (Paolo). - blk-mq atomic flags memory ordering fixes (Peter Z). - Loop cgroup support (Shaohua). - Lots of minor fixes from lots of different folks, both for core and driver code" * 'for-4.15/block' of git://git.kernel.dk/linux-block: (294 commits) nvme: fix visibility of "uuid" ns attribute blk-mq: fixup some comment typos and lengths ide: ide-atapi: fix compile error with defining macro DEBUG blk-mq: improve tag waiting setup for non-shared tags brd: remove unused brd_mutex blk-mq: only run the hardware queue if IO is pending block: avoid null pointer dereference on null disk fs: guard_bio_eod() needs to consider partitions xtensa/simdisk: fix compile error nvme: expose subsys attribute to sysfs nvme: create 'slaves' and 'holders' entries for hidden controllers block: create 'slaves' and 'holders' entries for hidden gendisks nvme: also expose the namespace identification sysfs files for mpath nodes nvme: implement multipath access to nvme subsystems nvme: track shared namespaces nvme: introduce a nvme_ns_ids structure nvme: track subsystems block, nvme: Introduce blk_mq_req_flags_t block, scsi: Make SCSI quiesce and resume work reliably block: Add the QUEUE_FLAG_PREEMPT_ONLY request queue flag ...
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-16bcache: implement PI controller for writeback rateMichael Lyle
bcache uses a control system to attempt to keep the amount of dirty data in cache at a user-configured level, while not responding excessively to transients and variations in write rate. Previously, the system was a PD controller; but the output from it was integrated, turning the Proportional term into an Integral term, and turning the Derivative term into a crude Proportional term. Performance of the controller has been uneven in production, and it has tended to respond slowly, oscillate, and overshoot. This patch set replaces the current control system with an explicit PI controller and tuning that should be correct for most hardware. By default, it attempts to write at a rate that would retire 1/40th of the current excess blocks per second. An integral term in turn works to remove steady state errors. IMO, this yields benefits in simplicity (removing weighted average filtering, etc) and system performance. Another small change is a tunable parameter is introduced to allow the user to specify a minimum rate at which dirty blocks are retired. There is a slight difference from earlier versions of the patch in integral handling to prevent excessive negative integral windup. Signed-off-by: Michael Lyle <mlyle@lyle.org> Reviewed-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-16bcache: Avoid nested function definitionPeter Foley
Fixes below error with clang: ../drivers/md/bcache/sysfs.c:759:3: error: function definition is not allowed here { return *((uint16_t *) r) - *((uint16_t *) l); } ^ ../drivers/md/bcache/sysfs.c:789:32: error: use of undeclared identifier 'cmp' sort(p, n, sizeof(uint16_t), cmp, NULL); ^ 2 errors generated. v2: rename function to __bch_cache_cmp Signed-off-by: Peter Foley <pefoley2@pefoley.com> Reviewed-by: Coly Li <colyli@suse.de> Reviewed-by: Michael Lyle <mlyle@lyle.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-09-06bcache: Correct return value for sysfs attach errorsTony Asleson
If you encounter any errors in bch_cached_dev_attach it will return a negative error code. The variable 'v' which stores the result is unsigned, thus user space sees a very large value returned for bytes written which can cause incorrect user space behavior. Utilize 1 signed variable to use throughout the function to preserve error return capability. Signed-off-by: Tony Asleson <tasleson@redhat.com> Acked-by: Coly Li <colyli@suse.de> Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-09-06bcache: gc does not work when triggering by manual commandTang Junhui
I try to execute the following command to trigger gc thread: [root@localhost internal]# echo 1 > trigger_gc But it does not work, I debug the code in gc_should_run(), It works only if in invalidating or sectors_to_gc < 0. So set sectors_to_gc to -1 to meet the condition when we trigger gc by manual command. (Code comments aded by Coly Li) Signed-off-by: Tang Junhui <tang.junhui@zte.com.cn> Reviewed-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-03-02sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar
<linux/sched/clock.h> We are going to split <linux/sched/clock.h> out of <linux/sched.h>, which will have to be picked up from other headers and .c files. Create a trivial placeholder <linux/sched/clock.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-03-18bcache: remove nested function usageJohn Sheu
Uninlined nested functions can cause crashes when using ftrace, as they don't follow the normal calling convention and confuse the ftrace function graph tracer as it examines the stack. Also, nested functions are supported as a gcc extension, but may fail on other compilers (e.g. llvm). Signed-off-by: John Sheu <john.sheu@gmail.com>
2014-03-18bcache: Rework btree cache reserve handlingKent Overstreet
This changes the bucket allocation reserves to use _real_ reserves - separate freelists - instead of watermarks, which if nothing else makes the current code saner to reason about and is going to be important in the future when we add support for multiple btrees. It also adds btree_check_reserve(), which checks (and locks) the reserves for both bucket allocation and memory allocation for btree nodes; the old code just kinda sorta assumed that since (e.g. for btree node splits) it had the root locked and that meant no other threads could try to make use of the same reserve; this technically should have been ok for memory allocation (we should always have a reserve for memory allocation (the btree node cache is used as a reserve and we preallocate it)), but multiple btrees will mean that locking the root won't be sufficient anymore, and for the bucket allocation reserve it was technically possible for the old code to deadlock. Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-03-18bcache: Improve priority_statsKent Overstreet
Break down data into clean data/dirty data/metadata. Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-01-29bcache: Minor fixes from kbuild robotKent Overstreet
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-01-08bcache: Convert btree_iter to struct btree_keysKent Overstreet
More work to disentangle bset.c from struct btree Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-01-08bcache: Refactor bset_tree sysfs statsKent Overstreet
We're in the process of turning bset.c into library code, so none of the code in that file should know about struct cache_set or struct btree - so, move the btree traversal part of the stats code to sysfs.c. Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-01-08bcache: Add struct btree_keysKent Overstreet
Soon, bset.c won't need to depend on struct btree. Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-01-08bcache: Add struct bset_sort_stateKent Overstreet
More disentangling bset.c from the rest of the bcache code - soon, the sorting routines won't have any dependencies on any outside structs. Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-01-08bcache: Rework allocator reservesKent Overstreet
We need a reserve for allocating buckets for new btree nodes - and now that we've got multiple btrees, it really needs to be per btree. This reworks the reserves so we've got separate freelists for each reserve instead of watermarks, which seems to make things a bit cleaner, and it adds some code so that btree_split() can make sure the reserve is available before it starts. Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-12-16bcache: New writeback PD controllerKent Overstreet
The old writeback PD controller could get into states where it had throttled all the way down and take way too long to recover - it was too complicated to really understand what it was doing. This rewrites a good chunk of it to hopefully be simpler and make more sense, and it also pays more attention to units which should make the behaviour a bit easier to understand. Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-10bcache: Bypass torture testKent Overstreet
More testing ftw! Also, now verify mode doesn't break if you read dirty data. Signed-off-by: Kent Overstreet <kmo@daterainc.com>