1What: /sys/fs/erofs/features/ 2Date: November 2021 3Contact: "Huang Jianan" <huangjianan@oppo.com> 4Description: Shows all enabled kernel features. 5 Supported features: 6 compr_cfgs, big_pcluster, chunked_file, device_table, 7 compr_head2, sb_chksum, ztailpacking, dedupe, fragments, 8 48bit, metabox. 9 10What: /sys/fs/erofs/<disk>/sync_decompress 11Date: November 2021 12Contact: "Huang Jianan" <huangjianan@oppo.com> 13Description: Control strategy of synchronous decompression. Synchronous 14 decompression tries to decompress in the reader thread for 15 synchronous reads and small asynchronous reads (<= 12 KiB): 16 17 - 0 (auto, default): apply to synchronous reads only, but will 18 switch to 1 (force on) if any decompression 19 request is detected in atomic contexts; 20 - 1 (force on): apply to synchronous reads and small 21 asynchronous reads; 22 - 2 (force off): disable synchronous decompression completely. 23 24What: /sys/fs/erofs/<disk>/drop_caches 25Date: November 2024 26Contact: "Guo Chunhai" <guochunhai@vivo.com> 27Description: Writing to this will drop compression-related caches, 28 currently used to drop in-memory pclusters and cached 29 compressed folios: 30 31 - 1 : invalidate cached compressed folios 32 - 2 : drop in-memory pclusters 33 - 3 : drop in-memory pclusters and cached compressed folios 34 35What: /sys/fs/erofs/accel 36Date: May 2025 37Contact: "Bo Liu" <liubo03@inspur.com> 38Description: Used to set or show hardware accelerators in effect 39 and multiple accelerators are separated by '\n'. 40 Supported accelerator(s): qat_deflate. 41 Disable all accelerators with an empty string (echo > accel). 42 43What: /sys/fs/erofs/<disk>/dir_ra_bytes 44Date: July 2025 45Contact: "Chao Yu" <chao@kernel.org> 46Description: Used to set or show readahead bytes during readdir(), by 47 default the value is 16384. 48 49 - 0: disable readahead. 50