From 4725e543be32f74d3a0a46ce3bb5c8e89280b471 Mon Sep 17 00:00:00 2001 From: Rob N Date: Tue, 16 Apr 2024 06:52:20 +1000 Subject: [PATCH] zinject: "no-op" error injection When injected, this causes the matching IO to appear to succeed, but the actual work is never submitted to the physical device. This can be used to simulate a write-back cache servicing a write, but the backing device has failed and the cache cannot complete the operation in the background. Sponsored-by: Klara, Inc. Sponsored-by: Wasabi Technology, Inc. Reviewed-by: Brian Behlendorf Signed-off-by: Rob Norris Closes #16085 --- cmd/zinject/zinject.c | 7 ++++--- man/man8/zinject.8 | 6 ++++-- module/zfs/zio.c | 10 ++++++++++ .../tests/functional/cli_root/zinject/zinject_args.ksh | 2 +- 4 files changed, 19 insertions(+), 6 deletions(-) diff --git a/cmd/zinject/zinject.c b/cmd/zinject/zinject.c index a1afa4a63f..e9141fb4ba 100644 --- a/cmd/zinject/zinject.c +++ b/cmd/zinject/zinject.c @@ -221,6 +221,7 @@ static const struct errstr errstrtable[] = { { ENXIO, "nxio" }, { ECHILD, "dtl" }, { EILSEQ, "corrupt" }, + { ENOSYS, "noop" }, { 0, NULL }, }; @@ -269,8 +270,8 @@ usage(void) "\t\tInject a fault into a particular device or the device's\n" "\t\tlabel. Label injection can either be 'nvlist', 'uber',\n " "\t\t'pad1', or 'pad2'.\n" - "\t\t'errno' can be 'nxio' (the default), 'io', 'dtl', or\n" - "\t\t'corrupt' (bit flip).\n" + "\t\t'errno' can be 'nxio' (the default), 'io', 'dtl',\n" + "\t\t'corrupt' (bit flip), or 'noop' (successfully do nothing).\n" "\t\t'frequency' is a value between 0.0001 and 100.0 that limits\n" "\t\tdevice error injection to a percentage of the IOs.\n" "\n" @@ -889,7 +890,7 @@ main(int argc, char **argv) if (error < 0) { (void) fprintf(stderr, "invalid error type " "'%s': must be one of: io decompress " - "decrypt nxio dtl corrupt\n", + "decrypt nxio dtl corrupt noop\n", optarg); usage(); libzfs_fini(g_zfs); diff --git a/man/man8/zinject.8 b/man/man8/zinject.8 index 817dcb7fe3..f67b5e378d 100644 --- a/man/man8/zinject.8 +++ b/man/man8/zinject.8 @@ -211,9 +211,11 @@ to flip a bit in the data after a read, .It Sy dtl for an ECHILD error, .It Sy io -for an EIO error where reopening the device will succeed, or +for an EIO error where reopening the device will succeed, .It Sy nxio -for an ENXIO error where reopening the device will fail. +for an ENXIO error where reopening the device will fail, or +.It Sy noop +to drop the IO without executing it, and return success. .El .Pp For EIO and ENXIO, the "failed" reads or writes still occur. diff --git a/module/zfs/zio.c b/module/zfs/zio.c index 8d8523038e..414e3d4e93 100644 --- a/module/zfs/zio.c +++ b/module/zfs/zio.c @@ -4058,6 +4058,16 @@ zio_vdev_io_start(zio_t *zio) zio->io_type == ZIO_TYPE_WRITE || zio->io_type == ZIO_TYPE_TRIM)) { + if (zio_handle_device_injection(vd, zio, ENOSYS) != 0) { + /* + * "no-op" injections return success, but do no actual + * work. Just skip the remaining vdev stages. + */ + zio_vdev_io_bypass(zio); + zio_interrupt(zio); + return (NULL); + } + if ((zio = vdev_queue_io(zio)) == NULL) return (NULL); diff --git a/tests/zfs-tests/tests/functional/cli_root/zinject/zinject_args.ksh b/tests/zfs-tests/tests/functional/cli_root/zinject/zinject_args.ksh index f8a8ffbb7b..dd9ef9ddd2 100755 --- a/tests/zfs-tests/tests/functional/cli_root/zinject/zinject_args.ksh +++ b/tests/zfs-tests/tests/functional/cli_root/zinject/zinject_args.ksh @@ -47,7 +47,7 @@ function cleanup function test_device_fault { - typeset -a errno=("io" "decompress" "decrypt" "nxio" "dtl" "corrupt") + typeset -a errno=("io" "decompress" "decrypt" "nxio" "dtl" "corrupt" "noop") for e in ${errno[@]}; do log_must eval \ "zinject -d $DISK1 -e $e -T read -f 0.001 $TESTPOOL"