kernel/linux.git/fs/squashfs/block.c, branch v6.18.22

block: add a bio_init_inline helper

2025-09-09T13:31:59+00:00

Just a simpler wrapper around bio_init for callers that want to initialize a bio with inline bvecs. Signed-off-by: Christoph Hellwig Reviewed-by: John Garry Reviewed-by: Yu Kuai Signed-off-by: Jens Axboe

squashfs: fix incorrect argument to sizeof in kmalloc_array call

2025-07-20T02:08:27+00:00

The sizeof(void *) is the incorrect argument in the kmalloc_array call, it best to fix this by using sizeof(*cache_folios) instead. Fortunately the sizes of void* and folio* happen to be the same, so this has not shown up as a run time issue. [akpm@linux-foundation.org: fix build] Link: https://lkml.kernel.org/r/20250708142604.1891156-1-colin.i.king@gmail.com Fixes: 2e227ff5e272 ("squashfs: add optional full compressed block caching") Signed-off-by: Colin Ian King Cc: Phillip Lougher Cc: Chanho Min Signed-off-by: Andrew Morton

squashfs: replace ;; with ; and end of fi declaration

2025-07-20T02:08:27+00:00

There is an extraneous ; after a declaration, remove it. Link: https://lkml.kernel.org/r/20250708114900.1883130-1-colin.i.king@gmail.com Signed-off-by: Colin Ian King Reviewed-by: Phillip Lougher Signed-off-by: Andrew Morton

squashfs: use folios in squashfs_bio_read_cached()

2025-07-10T05:57:51+00:00

Remove an access to page->mapping and a few calls to the old page-based APIs. This doesn't support large folios, but it's still a nice improvement. Link: https://lkml.kernel.org/r/20250612143903.2849289-3-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Cc: Phillip Lougher Signed-off-by: Andrew Morton

squashfs: add optional full compressed block caching

2025-05-28T02:40:33+00:00

The commit 93e72b3c612adcaca1 ("squashfs: migrate from ll_rw_block usage to BIO") removed caching of compressed blocks in SquashFS, causing fio performance regression in workloads with repeated file reads. Without caching, every read triggers disk I/O, severely impacting performance in tools like fio. This patch introduces a new CONFIG_SQUASHFS_COMP_CACHE_FULL Kconfig option to enable caching of all compressed blocks, restoring performance to pre-BIO migration levels. When enabled, all pages in a BIO are cached in the page cache, reducing disk I/O for repeated reads. The fio test results with this patch confirm the performance restoration: For example, fio tests (iodepth=1, numjobs=1, ioengine=psync) show a notable performance restoration: Disable CONFIG_SQUASHFS_COMP_CACHE_FULL: IOPS=815, BW=102MiB/s (107MB/s)(6113MiB/60001msec) Enable CONFIG_SQUASHFS_COMP_CACHE_FULL: IOPS=2223, BW=278MiB/s (291MB/s)(16.3GiB/59999msec) The tradeoff is increased memory usage due to caching all compressed blocks. The CONFIG_SQUASHFS_COMP_CACHE_FULL option allows users to enable this feature selectively, balancing performance and memory usage for workloads with frequent repeated reads. Link: https://lkml.kernel.org/r/20250521072559.2389-1-chanho.min@lge.com Signed-off-by: Chanho Min Reviewed-by Phillip Lougher Signed-off-by: Andrew Morton

squashfs: squashfs_read_data need to check if the length is 0

2023-12-07T00:12:45+00:00

When the length passed in is 0, the pagemap_scan_test_walk() caller should bail. This error causes at least a WARN_ON(). Link: https://lkml.kernel.org/r/20231116031352.40853-1-lizhi.xu@windriver.com Reported-by: syzbot+32d3767580a1ea339a81@syzkaller.appspotmail.com Closes: https://lkml.kernel.org/r/0000000000000526f2060a30a085@google.com Signed-off-by: Lizhi Xu Reviewed-by: Phillip Lougher Signed-off-by: Andrew Morton

squashfs: fix cache race with migration

2023-07-08T16:29:30+00:00

Migration replaces the page in the mapping before copying the contents and the flags over from the old page, so check that the page in the page cache is really up to date before using it. Without this, stressing squashfs reads with parallel compaction sometimes results in squashfs reporting data corruption. Link: https://lkml.kernel.org/r/20230629-squashfs-cache-migration-v1-1-d50ebe55099d@axis.com Fixes: e994f5b677ee ("squashfs: cache partial compressed blocks") Signed-off-by: Vincent Whitchurch Cc: Christoph Hellwig Cc: Phillip Lougher Signed-off-by: Andrew Morton

squashfs: cache partial compressed blocks

2023-06-10T00:44:14+00:00

Before commit 93e72b3c612adcaca1 ("squashfs: migrate from ll_rw_block usage to BIO"), compressed blocks read by squashfs were cached in the page cache, but that is not the case after that commit. That has lead to squashfs having to re-read a lot of sectors from disk/flash. For example, the first sectors of every metadata block need to be read twice from the disk. Once partially to read the length, and a second time to read the block itself. Also, in linear reads of large files, the last sectors of one data block are re-read from disk when reading the next data block, since the compressed blocks are of variable sizes and not aligned to device blocks. This extra I/O results in a degrade in read performance of, for example, ~16% in one scenario on my ARM platform using squashfs with dm-verity and NAND. Since the decompressed data is cached in the page cache or squashfs' internal metadata and fragment caches, caching _all_ compressed pages would lead to a lot of double caching and is undesirable. But make the code cache any disk blocks which were only partially requested, since these are the ones likely to include data which is needed by other file system blocks. This restores read performance in my test scenario. The compressed block caching is only applied when the disk block size is equal to the page size, to avoid having to deal with caching sub-page reads. [akpm@linux-foundation.org: fs/squashfs/block.c needs linux/pagemap.h] [vincent.whitchurch@axis.com: fix page update race] Link: https://lkml.kernel.org/r/20230526-squashfs-cache-fixup-v1-1-d54a7fa23e7b@axis.com [vincent.whitchurch@axis.com: fix page indices] Link: https://lkml.kernel.org/r/20230526-squashfs-cache-fixup-v1-2-d54a7fa23e7b@axis.com [akpm@linux-foundation.org: fix layout, per hch] Link: https://lkml.kernel.org/r/20230510-squashfs-cache-v4-1-3bd394e1ee71@axis.com Signed-off-by: Vincent Whitchurch Reviewed-by: Christoph Hellwig Reviewed-by: Phillip Lougher Signed-off-by: Andrew Morton

squashfs: don't include buffer_head.h

2023-06-10T00:44:14+00:00

Squashfs has stopped using buffers heads in 93e72b3c612adcaca1 ("squashfs: migrate from ll_rw_block usage to BIO"). Link: https://lkml.kernel.org/r/20230517071622.245151-1-hch@lst.de Signed-off-by: Christoph Hellwig Reviewed-by: Pankaj Raghav Reviewed-by: Phillip Lougher Signed-off-by: Andrew Morton

squashfs: add the mount parameter theads=

2022-11-18T21:55:08+00:00

Patch series 'squashfs: Add the mount parameter "threads="'. Currently, Squashfs supports multiple decompressor parallel modes. However, this mode can be configured only during kernel building and does not support flexible selection during runtime. In the current patch set, the mount parameter "threads=" is added to allow users to select the parallel decompressor mode and configure the number of decompressors when mounting a file system. "threads=" The upper limit is num_online_cpus() * 2. This patch (of 2): Squashfs supports three decompression concurrency modes: Single-thread mode: concurrent reads are blocked and the memory overhead is small. Multi-thread mode/percpu mode: reduces concurrent read blocking but increases memory overhead. The corresponding schema must be fixed at compile time. During mounting, the concurrent decompression mode cannot be adjusted based on file read blocking. The mount parameter theads= is added to select the concurrent decompression mode of a single SquashFS file system image. Link: https://lkml.kernel.org/r/20221019030930.130456-1-nixiaoming@huawei.com Link: https://lkml.kernel.org/r/20221019030930.130456-2-nixiaoming@huawei.com Signed-off-by: Xiaoming Ni Reviewed-by: Phillip Lougher Cc: Jianguo Chen Cc: Jubin Zhong Cc: Zhang Yi Signed-off-by: Andrew Morton