From a9ed3aa9b87ee41e8ab3ff471b1331c154767e45 Mon Sep 17 00:00:00 2001 From: Dave Airlie Date: Sat, 26 Sep 2026 07:57:59 +1000 Subject: Merge tag 'drm-misc-fixes-2026-09-24' of https://gitlab.freedesktop.org/drm/misc/kernel into drm-fixes A number of fixes: - bridge: - samsung-dsim: fix GPIO lifetime - client: Null pointer dereference fix - imagination: error handling fix, page handling fix - nouveau: fix reference leaks, double-frees, out-of-bounds accesses, use-after-frees, don't reject config without SCDC, a number of workarounds - virtio: fix memory leak, reference leaks, null pointer dereference, add pixel blend mode, cache coherency fix Signed-off-by: Dave Airlie From: Maxime Ripard Link: https://patch.msgid.link/arU22zzqUGDEco1y@houat --- Documentation/block/error-injection.rst | 59 +++++++++++++++++++++++++++++++++ 1 file changed, 59 insertions(+) create mode 100644 Documentation/block/error-injection.rst (limited to 'Documentation/block/error-injection.rst') diff --git a/Documentation/block/error-injection.rst b/Documentation/block/error-injection.rst new file mode 100644 index 000000000..81f31af82 --- /dev/null +++ b/Documentation/block/error-injection.rst @@ -0,0 +1,59 @@ +.. SPDX-License-Identifier: GPL-2.0 + +============================ +Configurable Error Injection +============================ + +Overview +-------- + +Configurable error injection allows injecting specific block layer status codes +for sector ranges of a block device. Errors can be injected unconditionally, or +with a given probability. + +To use configurable error injection, CONFIG_BLK_ERROR_INJECTION must be enabled. + +The only interface is the error_injection debugfs file, which is created for +each registered gendisk. Writes to this file are used to create or delete rules +and reads return a list of the current error injection sites. + +Options +------- + +The following options specify the operations: + +=================== ======================================================= +add add a new rule +removeall remove all existing rules +=================== ======================================================= + +The following options specify the details of the rule for the add operation: + +=================== ======================================================= +op= block layer operation this rule applies to. This uses + the XYZ for each REQ_OP_XYZ operation, e.g. READ, WRITE + or DISCARD. Mandatory. +status= Status to return. This uses XYZ for each BLK_STS_XYZ + code, e.g. IOERR or MEDIUM. Mandatory. +start= First block layer sector the rule applies to. + Optional, defaults to 0. +nr_sectors= Number of sectors this rule applies. + Optional, defaults to the remainder of the device. +chance= Only return a failure with a likelihood of 1/chance. + Optional, defaults to 1 (always). +=================== ======================================================= + +Example +------- + +Return BLK_STS_IOERR for one in 10 reads of sector 0 of /dev/nvme0n1: + + $ echo 'add,op=READ,start=0,status=IOERR,chance=10' > /sys/kernel/debug/block/nvme0n1/error_injection + +Return BLK_STS_MEDIUM for every write to /dev/nvme0n1: + + $ echo 'add,op=WRITE,start=0,status=MEDIUM' > /sys/kernel/debug/block/nvme0n1/error_injection + +Remove all rules for /dev/nvme0n1: + + $ echo 'removeall' > /sys/kernel/debug/block/nvme0n1/error_injection -- cgit v1.3.1