diff options
Diffstat (limited to 'Documentation/ABI')
| -rw-r--r-- | Documentation/ABI/stable/sysfs-block | 33 | ||||
| -rw-r--r-- | Documentation/ABI/testing/sysfs-fs-erofs | 10 |
2 files changed, 42 insertions, 1 deletions
diff --git a/Documentation/ABI/stable/sysfs-block b/Documentation/ABI/stable/sysfs-block index 4ba771b56b3b..803f578dc023 100644 --- a/Documentation/ABI/stable/sysfs-block +++ b/Documentation/ABI/stable/sysfs-block @@ -778,6 +778,39 @@ Description: 0, write zeroes is not supported by the device. +What: /sys/block/<disk>/queue/write_zeroes_unmap_max_hw_bytes +Date: January 2025 +Contact: Zhang Yi <yi.zhang@huawei.com> +Description: + [RO] This file indicates whether a device supports zeroing data + in a specified block range without incurring the cost of + physically writing zeroes to the media for each individual + block. If this parameter is set to write_zeroes_max_bytes, the + device implements a zeroing operation which opportunistically + avoids writing zeroes to media while still guaranteeing that + subsequent reads from the specified block range will return + zeroed data. This operation is a best-effort optimization, a + device may fall back to physically writing zeroes to the media + due to other factors such as misalignment or being asked to + clear a block range smaller than the device's internal + allocation unit. If this parameter is set to 0, the device may + have to write each logical block media during a zeroing + operation. + + +What: /sys/block/<disk>/queue/write_zeroes_unmap_max_bytes +Date: January 2025 +Contact: Zhang Yi <yi.zhang@huawei.com> +Description: + [RW] While write_zeroes_unmap_max_hw_bytes is the hardware limit + for the device, this setting is the software limit. Since the + unmap write zeroes operation is a best-effort optimization, some + devices may still physically writing zeroes to media. So the + speed of this operation is not guaranteed. Writing a value of + '0' to this file disables this operation. Otherwise, this + parameter should be equal to write_zeroes_unmap_max_hw_bytes. + + What: /sys/block/<disk>/queue/zone_append_max_bytes Date: May 2020 Contact: linux-block@vger.kernel.org diff --git a/Documentation/ABI/testing/sysfs-fs-erofs b/Documentation/ABI/testing/sysfs-fs-erofs index bf3b6299c15e..76d9808ed581 100644 --- a/Documentation/ABI/testing/sysfs-fs-erofs +++ b/Documentation/ABI/testing/sysfs-fs-erofs @@ -5,7 +5,7 @@ Description: Shows all enabled kernel features. Supported features: zero_padding, compr_cfgs, big_pcluster, chunked_file, device_table, compr_head2, sb_chksum, ztailpacking, - dedupe, fragments. + dedupe, fragments, 48bit, metabox. What: /sys/fs/erofs/<disk>/sync_decompress Date: November 2021 @@ -35,3 +35,11 @@ Description: Used to set or show hardware accelerators in effect and multiple accelerators are separated by '\n'. Supported accelerator(s): qat_deflate. Disable all accelerators with an empty string (echo > accel). + +What: /sys/fs/erofs/<disk>/dir_ra_bytes +Date: July 2025 +Contact: "Chao Yu" <chao@kernel.org> +Description: Used to set or show readahead bytes during readdir(), by + default the value is 16384. + + - 0: disable readahead. |