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Diffstat (limited to 'Documentation/fault-injection/fault-injection.txt')
| -rw-r--r-- | Documentation/fault-injection/fault-injection.txt | 70 |
1 files changed, 69 insertions, 1 deletions
diff --git a/Documentation/fault-injection/fault-injection.txt b/Documentation/fault-injection/fault-injection.txt index 918972babcd8..de1dc35fe500 100644 --- a/Documentation/fault-injection/fault-injection.txt +++ b/Documentation/fault-injection/fault-injection.txt @@ -1,7 +1,7 @@ Fault injection capabilities infrastructure =========================================== -See also drivers/md/faulty.c and "every_nth" module option for scsi_debug. +See also drivers/md/md-faulty.c and "every_nth" module option for scsi_debug. Available fault injection capabilities @@ -30,6 +30,12 @@ o fail_mmc_request injects MMC data errors on devices permitted by setting debugfs entries under /sys/kernel/debug/mmc0/fail_mmc_request +o fail_function + + injects error return on specific functions, which are marked by + ALLOW_ERROR_INJECTION() macro, by setting debugfs entries + under /sys/kernel/debug/fail_function. No boot option supported. + Configure fault-injection capabilities behavior ----------------------------------------------- @@ -123,6 +129,29 @@ configuration of fault-injection capabilities. default is 'N', setting it to 'Y' will disable failure injections when dealing with private (address space) futexes. +- /sys/kernel/debug/fail_function/inject: + + Format: { 'function-name' | '!function-name' | '' } + specifies the target function of error injection by name. + If the function name leads '!' prefix, given function is + removed from injection list. If nothing specified ('') + injection list is cleared. + +- /sys/kernel/debug/fail_function/injectable: + + (read only) shows error injectable functions and what type of + error values can be specified. The error type will be one of + below; + - NULL: retval must be 0. + - ERRNO: retval must be -1 to -MAX_ERRNO (-4096). + - ERR_NULL: retval must be 0 or -1 to -MAX_ERRNO (-4096). + +- /sys/kernel/debug/fail_function/<functiuon-name>/retval: + + specifies the "error" return value to inject to the given + function for given function. This will be created when + user specifies new injection entry. + o Boot option In order to inject faults while debugfs is not available (early boot time), @@ -268,6 +297,45 @@ trap "echo 0 > /sys/kernel/debug/$FAILTYPE/probability" SIGINT SIGTERM EXIT echo "Injecting errors into the module $module... (interrupt to stop)" sleep 1000000 +------------------------------------------------------------------------------ + +o Inject open_ctree error while btrfs mount + +#!/bin/bash + +rm -f testfile.img +dd if=/dev/zero of=testfile.img bs=1M seek=1000 count=1 +DEVICE=$(losetup --show -f testfile.img) +mkfs.btrfs -f $DEVICE +mkdir -p tmpmnt + +FAILTYPE=fail_function +FAILFUNC=open_ctree +echo $FAILFUNC > /sys/kernel/debug/$FAILTYPE/inject +echo -12 > /sys/kernel/debug/$FAILTYPE/$FAILFUNC/retval +echo N > /sys/kernel/debug/$FAILTYPE/task-filter +echo 100 > /sys/kernel/debug/$FAILTYPE/probability +echo 0 > /sys/kernel/debug/$FAILTYPE/interval +echo -1 > /sys/kernel/debug/$FAILTYPE/times +echo 0 > /sys/kernel/debug/$FAILTYPE/space +echo 1 > /sys/kernel/debug/$FAILTYPE/verbose + +mount -t btrfs $DEVICE tmpmnt +if [ $? -ne 0 ] +then + echo "SUCCESS!" +else + echo "FAILED!" + umount tmpmnt +fi + +echo > /sys/kernel/debug/$FAILTYPE/inject + +rmdir tmpmnt +losetup -d $DEVICE +rm testfile.img + + Tool to run command with failslab or fail_page_alloc ---------------------------------------------------- In order to make it easier to accomplish the tasks mentioned above, we can use |