From 75467f60a3d14f08f86f2b353298d2826382ff23 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Fri, 25 Sep 2026 15:55:03 -0700 Subject: Merge tag 'ipe-pr-20260925' of git://git.kernel.org/pub/scm/linux/kernel/git/wufan/ipe Pull IPE fixes from Fan Wu: "Two fixes for use-after-free issues found by recent LLM-assisted code analysis. - move successful policy load auditing under the new policy directory's inode lock, preventing a concurrent policy deletion from freeing the policy while it is still being audited - protect the dm-verity root hash with RCU, preventing policy evaluation from racing with root hash replacement during preresume" * tag 'ipe-pr-20260925' of git://git.kernel.org/pub/scm/linux/kernel/git/wufan/ipe: ipe: protect the dm-verity root hash with RCU ipe: fix use-after-free when auditing a newly loaded policy --- Documentation/admin-guide/device-mapper/delay.rst | 54 +++++++++++++++++++++++ 1 file changed, 54 insertions(+) create mode 100644 Documentation/admin-guide/device-mapper/delay.rst (limited to 'Documentation/admin-guide/device-mapper/delay.rst') diff --git a/Documentation/admin-guide/device-mapper/delay.rst b/Documentation/admin-guide/device-mapper/delay.rst new file mode 100644 index 000000000..a1e673c0e --- /dev/null +++ b/Documentation/admin-guide/device-mapper/delay.rst @@ -0,0 +1,54 @@ +======== +dm-delay +======== + +Device-Mapper's "delay" target delays reads and/or writes +and/or flushes and optionally maps them to different devices. + +Arguments:: + + [ + [ ]] + +Table line has to either have 3, 6 or 9 arguments: + +3: apply offset and delay to read, write and flush operations on device + +6: apply offset and delay to device, also apply write_offset and write_delay + to write and flush operations on optionally different write_device with + optionally different sector offset + +9: same as 6 arguments plus define flush_offset and flush_delay explicitly + on/with optionally different flush_device/flush_offset. + +Offsets are specified in sectors. + +Delays are specified in milliseconds. + + +Example scripts +=============== + +:: + #!/bin/sh + # + # Create mapped device named "delayed" delaying read, write and flush operations for 500ms. + # + dmsetup create delayed --table "0 `blockdev --getsz $1` delay $1 0 500" + +:: + #!/bin/sh + # + # Create mapped device delaying write and flush operations for 400ms and + # splitting reads to device $1 but writes and flushes to different device $2 + # to different offsets of 2048 and 4096 sectors respectively. + # + dmsetup create delayed --table "0 `blockdev --getsz $1` delay $1 2048 0 $2 4096 400" + +:: + #!/bin/sh + # + # Create mapped device delaying reads for 50ms, writes for 100ms and flushes for 333ms + # onto the same backing device at offset 0 sectors. + # + dmsetup create delayed --table "0 `blockdev --getsz $1` delay $1 0 50 $2 0 100 $1 0 333" -- cgit v1.3.1