kernel/drivers/md/bcache/sysfs.c, branch linux-6.9.y

bcache: fix variable length array abuse in btree_iter

2024-06-16T11:50:55Z

commit 3a861560ccb35f2a4f0a4b8207fa7c2a35fc7f31 upstream. btree_iter is used in two ways: either allocated on the stack with a fixed size MAX_BSETS, or from a mempool with a dynamic size based on the specific cache set. Previously, the struct had a fixed-length array of size MAX_BSETS which was indexed out-of-bounds for the dynamically-sized iterators, which causes UBSAN to complain. This patch uses the same approach as in bcachefs's sort_iter and splits the iterator into a btree_iter with a flexible array member and a btree_iter_stack which embeds a btree_iter as well as a fixed-length data array. Cc: stable@vger.kernel.org Closes: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2039368 Signed-off-by: Matthew Mirvish Signed-off-by: Coly Li Link: https://lore.kernel.org/r/20240509011117.2697-3-colyli@suse.de Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

bcache: use of hlist_count_nodes()

2024-02-22T23:38:51Z

Make use of the newly added hlist_count_nodes(). Link: https://lkml.kernel.org/r/20240104164937.424320-4-pierre.gondois@arm.com Signed-off-by: Pierre Gondois Acked-by: Coly Li Acked-by: Marco Elver Reviewed-by: Andy Shevchenko Cc: Arve Hjønnevåg Cc: Carlos Llamas Cc: Christian Brauner Cc: Greg Kroah-Hartman Cc: Ingo Molnar Cc: Jani Nikula Cc: Joel Fernandes (Google) Cc: Kees Cook Cc: Kent Overstreet Cc: Martijn Coenen Cc: Suren Baghdasaryan Cc: Todd Kjos Signed-off-by: Andrew Morton

bcache: prevent potential division by zero error

2023-11-20T16:17:51Z

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 Cc: Signed-off-by: Coly Li Link: https://lore.kernel.org/r/20231120052503.6122-5-colyli@suse.de Signed-off-by: Jens Axboe

bcache: dynamically allocate the md-bcache shrinker

2023-10-04T17:32:25Z

In preparation for implementing lockless slab shrink, use new APIs to dynamically allocate the md-bcache shrinker, so that it can be freed asynchronously via RCU. Then it doesn't need to wait for RCU read-side critical section when releasing the struct cache_set. Link: https://lkml.kernel.org/r/20230911094444.68966-27-zhengqi.arch@bytedance.com Signed-off-by: Qi Zheng Acked-by: Muchun Song Cc: Coly Li Cc: Kent Overstreet Cc: Abhinav Kumar Cc: Alasdair Kergon Cc: Alexander Viro Cc: Alyssa Rosenzweig Cc: Andreas Dilger Cc: Andreas Gruenbacher Cc: Anna Schumaker Cc: Arnd Bergmann Cc: Bob Peterson Cc: Borislav Petkov Cc: Carlos Llamas Cc: Chandan Babu R Cc: Chao Yu Cc: Chris Mason Cc: Christian Brauner Cc: Christian Koenig Cc: Chuck Lever Cc: Dai Ngo Cc: Daniel Vetter Cc: Daniel Vetter Cc: "Darrick J. Wong" Cc: Dave Chinner Cc: Dave Hansen Cc: David Airlie Cc: David Hildenbrand Cc: David Sterba Cc: Dmitry Baryshkov Cc: Gao Xiang Cc: Greg Kroah-Hartman Cc: Huang Rui Cc: Ingo Molnar Cc: Jaegeuk Kim Cc: Jani Nikula Cc: Jan Kara Cc: Jason Wang Cc: Jeff Layton Cc: Jeffle Xu Cc: Joel Fernandes (Google) Cc: Joonas Lahtinen Cc: Josef Bacik Cc: Juergen Gross Cc: Kirill Tkhai Cc: Marijn Suijten Cc: "Michael S. Tsirkin" Cc: Mike Snitzer Cc: Minchan Kim Cc: Nadav Amit Cc: Neil Brown Cc: Oleksandr Tyshchenko Cc: Olga Kornievskaia Cc: Paul E. McKenney Cc: Richard Weinberger Cc: Rob Clark Cc: Rob Herring Cc: Rodrigo Vivi Cc: Roman Gushchin Cc: Sean Paul Cc: Sergey Senozhatsky Cc: Song Liu Cc: Stefano Stabellini Cc: Steven Price Cc: "Theodore Ts'o" Cc: Thomas Gleixner Cc: Tomeu Vizoso Cc: Tom Talpey Cc: Trond Myklebust Cc: Tvrtko Ursulin Cc: Vlastimil Babka Cc: Xuan Zhuo Cc: Yue Hu Signed-off-by: Andrew Morton

bcache: Convert to use sysfs_emit()/sysfs_emit_at() APIs

2023-06-15T13:30:11Z

Follow the advice of the Documentation/filesystems/sysfs.rst and show() should only use sysfs_emit() or sysfs_emit_at() when formatting the value to be returned to user space. Signed-off-by: ye xingchen Signed-off-by: Coly Li Link: https://lore.kernel.org/r/20230615121223.22502-2-colyli@suse.de Signed-off-by: Jens Axboe

block: remove QUEUE_FLAG_DISCARD

2022-04-18T01:49:59Z

Just use a non-zero max_discard_sectors as an indicator for discard support, similar to what is done for write zeroes. The only places where needs special attention is the RAID5 driver, which must clear discard support for security reasons by default, even if the default stacking rules would allow for it. Signed-off-by: Christoph Hellwig Reviewed-by: Martin K. Petersen Acked-by: Christoph Böhmwalder [drbd] Acked-by: Jan Höppner [s390] Acked-by: Coly Li [bcache] Acked-by: David Sterba [btrfs] Reviewed-by: Chaitanya Kulkarni Link: https://lore.kernel.org/r/20220415045258.199825-25-hch@lst.de Signed-off-by: Jens Axboe

bcache: use default_groups in kobj_type

2022-01-26T14:56:18Z

There are currently 2 ways to create a set of sysfs files for a kobj_type, through the default_attrs field, and the default_groups field. Move the bcache sysfs code to use default_groups field which has been the preferred way since aa30f47cf666 ("kobject: Add support for default attribute groups to kobj_type") so that we can soon get rid of the obsolete default_attrs field. Cc: Kent Overstreet Cc: linux-bcache@vger.kernel.org Acked-by: Coly Li Link: https://lore.kernel.org/r/20220106100004.3277439-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman

bcache: remove the backing_dev_name field from struct cached_dev

2021-10-20T14:40:54Z

Just use the %pg format specifier to print the name directly. Signed-off-by: Christoph Hellwig Signed-off-by: Coly Li Link: https://lore.kernel.org/r/20211020143812.6403-7-colyli@suse.de Signed-off-by: Jens Axboe

bcache: remove bcache device self-defined readahead

2021-06-08T21:06:03Z

For read cache missing, bcache defines a readahead size for the read I/O request to the backing device for the missing data. This readahead size is initialized to 0, and almost no one uses it to avoid unnecessary read amplifying onto backing device and write amplifying onto cache device. Considering upper layer file system code has readahead logic allready and works fine with readahead_cache_policy sysfile interface, we don't have to keep bcache self-defined readahead anymore. This patch removes the bcache self-defined readahead for cache missing request for backing device, and the readahead sysfs file interfaces are removed as well. This is the preparation for next patch to fix potential kernel panic due to oversized request in a simpler method. Reported-by: Alexander Ullrich Reported-by: Diego Ercolani Reported-by: Jan Szubiak Reported-by: Marco Rebhan Reported-by: Matthias Ferdinand Reported-by: Victor Westerhuis Reported-by: Vojtech Pavlik Reported-and-tested-by: Rolf Fokkens Reported-and-tested-by: Thorsten Knabe Signed-off-by: Coly Li Reviewed-by: Christoph Hellwig Cc: stable@vger.kernel.org Cc: Kent Overstreet Cc: Nix Cc: Takashi Iwai Link: https://lore.kernel.org/r/20210607125052.21277-2-colyli@suse.de Signed-off-by: Jens Axboe

bcache: Avoid comma separated statements

2021-02-10T15:06:00Z

Use semicolons and braces. Signed-off-by: Joe Perches Signed-off-by: Coly Li Signed-off-by: Jens Axboe