Kevin Wolf bf627788ef file-posix: Probe paths and retry SG_IO on potential path errors ... When scsi-block is used on a host multipath device, it runs into the problem that the kernel dm-mpath doesn't know anything about SCSI or SG_IO and therefore can't decide if a SG_IO request returned an error and needs to be retried on a different path. Instead of getting working failover, an error is returned to scsi-block and handled according to the configured error policy. Obviously, this is not what users want, they want working failover. QEMU can parse the SG_IO result and determine whether this could have been a path error, but just retrying the same request could just send it to the same failing path again and result in the same error. With a kernel that supports the DM_MPATH_PROBE_PATHS ioctl on dm-mpath block devices (queued in the device mapper tree for Linux 6.16), we can tell the kernel to probe all paths and tell us if any usable paths remained. If so, we can now retry the SG_IO ioctl and expect it to be sent to a working path. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-ID: <20250522130803.34738-1-kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Hanna Czenczek <hreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>		2025-05-22 17:56:50 +02:00
..
export	block/export: Add option to allow export of inactive nodes	2025-02-06 14:46:40 +01:00
monitor	nbd/server: Allow users to adjust handshake limit in QMP	2025-02-11 13:45:47 -06:00
accounting.c	include: Rename sysemu/ -> system/	2024-12-20 17:44:56 +01:00
aio_task.c	block: Remove unused aio_task_pool_empty	2024-09-30 10:53:18 +03:00
amend.c	block: Mark BlockDriver callbacks for amend job GRAPH_RDLOCK	2023-05-10 14:16:54 +02:00
backup.c	blockdev-backup: Add error handling option for copy-before-write jobs	2025-05-12 18:19:31 +03:00
blkdebug.c	block: Expand block status mode from bool to flags	2025-05-14 15:33:34 -05:00
blkio.c	include/system: Move exec/memory.h to system/memory.h	2025-04-23 14:08:21 -07:00
blklogwrites.c	qapi: Move include/qapi/qmp/ to include/qobject/	2025-02-10 15:33:16 +01:00
blkreplay.c	include: Rename sysemu/ -> system/	2024-12-20 17:44:56 +01:00
blkverify.c	qapi: Move include/qapi/qmp/ to include/qobject/	2025-02-10 15:33:16 +01:00
block-backend.c	block: Remove unused blk_op_is_blocked()	2025-03-11 15:49:14 +01:00
block-copy.c	include: Rename sysemu/ -> system/	2024-12-20 17:44:56 +01:00
block-gen.h	block-coroutine-wrapper.py: support also basic return types	2022-12-15 16:07:43 +01:00
block-ram-registrar.c	include: Rename sysemu/ -> system/	2024-12-20 17:44:56 +01:00
bochs.c	block: Take graph lock for most of .bdrv_open	2023-11-08 17:56:18 +01:00
cloop.c	block: Take graph lock for most of .bdrv_open	2023-11-08 17:56:18 +01:00
commit.c	block: allow commit to unmap zero blocks	2025-05-01 12:12:19 +03:00
copy-before-write.c	block: Expand block status mode from bool to flags	2025-05-14 15:33:34 -05:00
copy-before-write.h	blockdev-backup: Add error handling option for copy-before-write jobs	2025-05-12 18:19:31 +03:00
copy-on-read.c	qapi: Move include/qapi/qmp/ to include/qobject/	2025-02-10 15:33:16 +01:00
copy-on-read.h	block: Mark bdrv_(un)freeze_backing_chain() and callers GRAPH_RDLOCK	2023-11-07 19:14:19 +01:00
coroutines.h	block: Expand block status mode from bool to flags	2025-05-14 15:33:34 -05:00
create.c	qemu/compiler: Absorb 'clang-tsa.h'	2025-03-06 14:21:25 +01:00
crypto.c	include: Rename sysemu/ -> system/	2024-12-20 17:44:56 +01:00
crypto.h	block: Support detached LUKS header creation using qemu-img	2024-02-09 12:50:37 +00:00
curl.c	qapi: Move include/qapi/qmp/ to include/qobject/	2025-02-10 15:33:16 +01:00
dirty-bitmap.c	block: Mark bdrv_*_dirty_bitmap() and callers GRAPH_RDLOCK	2023-02-23 19:49:32 +01:00
dmg-bz2.c	Include qemu-common.h exactly where needed	2019-06-12 13:20:20 +02:00
dmg-lzfse.c	block/dmg: Ignore C99 prototype declaration mismatch from <lzfse.h>	2023-03-30 15:03:36 +02:00
dmg.c	block: Protect bs->file with graph_lock	2023-11-08 17:56:18 +01:00
dmg.h	block/dmg: Declare a type definition for DMG uncompress function	2023-04-24 13:53:44 -04:00
file-posix.c	file-posix: Probe paths and retry SG_IO on potential path errors	2025-05-22 17:56:50 +02:00
file-win32.c	qapi: Move include/qapi/qmp/ to include/qobject/	2025-02-10 15:33:16 +01:00
filter-compress.c	block: Take graph lock for most of .bdrv_open	2023-11-08 17:56:18 +01:00
gluster.c	file-posix, gluster: Handle zero block status hint better	2025-05-14 15:49:27 -05:00
graph-lock.c	graph-lock: remove AioContext locking	2023-12-21 22:49:27 +01:00
io.c	block: Add new bdrv_co_is_all_zeroes() function	2025-05-14 16:08:23 -05:00
io_uring.c	file-posix: Support FUA writes	2025-03-13 17:44:55 +01:00
iscsi-opts.c	modules: add block module annotations	2021-07-09 18:20:27 +02:00
iscsi.c	block: Expand block status mode from bool to flags	2025-05-14 15:33:34 -05:00
linux-aio.c	file-posix: Support FUA writes	2025-03-13 17:44:55 +01:00
meson.build	include: Rename sysemu/ -> system/	2024-12-20 17:44:56 +01:00
mirror.c	mirror: Reduce I/O when destination is detect-zeroes:unmap	2025-05-14 21:27:04 -05:00
nbd.c	block: Expand block status mode from bool to flags	2025-05-14 15:33:34 -05:00
nfs.c	qapi: Move include/qapi/qmp/ to include/qobject/	2025-02-10 15:33:16 +01:00
null.c	block: Expand block status mode from bool to flags	2025-05-14 15:33:34 -05:00
nvme.c	block/nvme: Use host PCI MMIO API	2025-05-08 10:21:10 -04:00
parallels-ext.c	qapi/crypto: Rename QCryptoHashAlgorithm to *Algo, and drop prefix	2024-09-10 14:02:16 +02:00
parallels.c	block: Expand block status mode from bool to flags	2025-05-14 15:33:34 -05:00
parallels.h	block: Protect bs->file with graph_lock	2023-11-08 17:56:18 +01:00
preallocate.c	block: Protect bs->file with graph_lock	2023-11-08 17:56:18 +01:00
progress_meter.c	coroutine: Clean up superfluous inclusion of qemu/lockable.h	2023-01-19 10:18:28 +01:00
qapi-system.c	qapi: Move include/qapi/qmp/ to include/qobject/	2025-02-10 15:33:16 +01:00
qapi.c	Block layer patches	2025-02-10 13:25:36 -05:00
qcow.c	block: Expand block status mode from bool to flags	2025-05-14 15:33:34 -05:00
qcow2-bitmap.c	block/qcow2-bitmap: Replace g_memdup() by g_memdup2()	2024-05-08 19:11:34 +02:00
qcow2-cache.c	qcow2: Mark qcow2_signal_corruption() and callers GRAPH_RDLOCK	2023-10-12 16:31:33 +02:00
qcow2-cluster.c	qcow2: Take locks for accessing bs->file	2023-11-08 17:56:17 +01:00
qcow2-refcount.c	qcow2: Mark qcow2_signal_corruption() and callers GRAPH_RDLOCK	2023-10-12 16:31:33 +02:00
qcow2-snapshot.c	include: Rename sysemu/ -> system/	2024-12-20 17:44:56 +01:00
qcow2-threads.c	thread-pool: avoid passing the pool parameter every time	2023-04-25 13:17:28 +02:00
qcow2.c	block: Expand block status mode from bool to flags	2025-05-14 15:33:34 -05:00
qcow2.h	qcow2: Take locks for accessing bs->file	2023-11-08 17:56:17 +01:00
qed-check.c	qed: mark more functions as coroutine_fns and GRAPH_RDLOCK	2023-06-28 09:46:20 +02:00
qed-cluster.c	qed: protect table cache with CoMutex	2017-07-17 11:34:11 +08:00
qed-l2-cache.c	osdep: Move memalign-related functions to their own header	2022-03-07 13:16:49 +00:00
qed-table.c	block: use bdrv_co_debug_event in coroutine context	2023-06-28 09:46:34 +02:00
qed.c	block: Expand block status mode from bool to flags	2025-05-14 15:33:34 -05:00
qed.h	block: Protect bs->file with graph_lock	2023-11-08 17:56:18 +01:00
quorum.c	block: Expand block status mode from bool to flags	2025-05-14 15:33:34 -05:00
raw-format.c	block: Expand block status mode from bool to flags	2025-05-14 15:33:34 -05:00
rbd.c	block: Expand block status mode from bool to flags	2025-05-14 15:33:34 -05:00
replication.c	blockdev-backup: Add error handling option for copy-before-write jobs	2025-05-12 18:19:31 +03:00
reqlist.c	block/reqlist: allow adding overlapping requests	2024-09-30 10:53:18 +03:00
snapshot-access.c	block: Expand block status mode from bool to flags	2025-05-14 15:33:34 -05:00
snapshot.c	block: Zero block driver state before reopening	2025-03-11 15:49:14 +01:00
ssh.c	qapi: Move include/qapi/qmp/ to include/qobject/	2025-02-10 15:33:16 +01:00
stream.c	qapi: Move include/qapi/qmp/ to include/qobject/	2025-02-10 15:33:16 +01:00
throttle-groups.c	qom: Make InterfaceInfo[] uses const	2025-04-25 17:00:41 +02:00
throttle.c	block: Take graph lock for most of .bdrv_open	2023-11-08 17:56:18 +01:00
trace-events	nbd/client: Accept 64-bit block status chunks	2023-10-05 11:02:08 -05:00
trace.h	trace: switch position of headers to what Meson requires	2020-08-21 06:18:24 -04:00
vdi.c	block: Expand block status mode from bool to flags	2025-05-14 15:33:34 -05:00
vhdx-endian.c	Include qemu-common.h exactly where needed	2019-06-12 13:20:20 +02:00
vhdx-log.c	vhdx: Take locks for accessing bs->file	2023-11-08 17:56:18 +01:00
vhdx.c	qapi: Move include/qapi/qmp/ to include/qobject/	2025-02-10 15:33:16 +01:00
vhdx.h	vhdx: Take locks for accessing bs->file	2023-11-08 17:56:18 +01:00
vmdk.c	block: Expand block status mode from bool to flags	2025-05-14 15:33:34 -05:00
vpc.c	block: Expand block status mode from bool to flags	2025-05-14 15:33:34 -05:00
vvfat.c	block: Expand block status mode from bool to flags	2025-05-14 15:33:34 -05:00
win32-aio.c	aio: remove aio_disable_external() API	2023-05-30 17:37:26 +02:00
write-threshold.c	block: remove AioContext locking	2023-12-21 22:49:27 +01:00