1.. SPDX-License-Identifier: GPL-2.0 2 3================================================= 4incfs: A stacked incremental filesystem for Linux 5================================================= 6 7/sys/fs interface 8================= 9 10Please update Documentation/ABI/testing/sysfs-fs-incfs if you update this 11section. 12 13incfs creates the following files in /sys/fs. 14 15Features 16-------- 17 18/sys/fs/incremental-fs/features/corefs 19 Reads 'supported'. Always present. 20 21/sys/fs/incremental-fs/features/v2 22 Reads 'supported'. Present if all v2 features of incfs are supported. These 23 are: 24 fs-verity support 25 inotify support 26 ioclts: 27 INCFS_IOC_SET_READ_TIMEOUTS 28 INCFS_IOC_GET_READ_TIMEOUTS 29 INCFS_IOC_GET_BLOCK_COUNT 30 INCFS_IOC_CREATE_MAPPED_FILE 31 .incomplete folder 32 .blocks_written pseudo file 33 report_uid mount option 34 35/sys/fs/incremental-fs/features/zstd 36 Reads 'supported'. Present if zstd compression is supported for data blocks. 37 38/sys/fs/incremental-fs/features/bugfix_throttling 39 Reads 'supported'. Present if the throttling lock bug is fixed 40 41Optional per mount 42------------------ 43 44For each incfs mount, the mount option sysfs_name=[name] creates a /sys/fs 45node called: 46 47/sys/fs/incremental-fs/instances/[name] 48 49This will contain the following files: 50 51/sys/fs/incremental-fs/instances/[name]/reads_delayed_min 52 Returns a count of the number of reads that were delayed as a result of the 53 per UID read timeouts min time setting. 54 55/sys/fs/incremental-fs/instances/[name]/reads_delayed_min_us 56 Returns total delay time for all files since first mount as a result of the 57 per UID read timeouts min time setting. 58 59/sys/fs/incremental-fs/instances/[name]/reads_delayed_pending 60 Returns a count of the number of reads that were delayed as a result of 61 waiting for a pending read. 62 63/sys/fs/incremental-fs/instances/[name]/reads_delayed_pending_us 64 Returns total delay time for all files since first mount as a result of 65 waiting for a pending read. 66 67/sys/fs/incremental-fs/instances/[name]/reads_failed_hash_verification 68 Returns number of reads that failed because of hash verification failures. 69 70/sys/fs/incremental-fs/instances/[name]/reads_failed_other 71 Returns number of reads that failed for reasons other than timing out or 72 hash failures. 73 74/sys/fs/incremental-fs/instances/[name]/reads_failed_timed_out 75 Returns number of reads that timed out. 76 77For reads_delayed_*** settings, note that a file can count for both 78reads_delayed_min and reads_delayed_pending if incfs first waits for a pending 79read then has to wait further for the min time. In that case, the time spent 80waiting is split between reads_delayed_pending_us, which is increased by the 81time spent waiting for the pending read, and reads_delayed_min_us, which is 82increased by the remainder of the time spent waiting. 83 84Reads that timed out are not added to the reads_delayed_pending or the 85reads_delayed_pending_us counters. 86