mirror_zfs/module/os/linux/zfs
Rob Norris 670147be53 zvol: ensure device minors are properly cleaned up
Currently, if a minor is in use when we try to remove it, we'll skip it
and never come back to it again. Since the zvol state is hung off the
minor in the kernel, this can get us into weird situations if something
tries to use it after the removal fails. It's even worse at pool export,
as there's now a vestigial zvol state with no pool under it. It's
weirder again if the pool is subsequently reimported, as the zvol code
(reasonably) assumes the zvol state has been properly setup, when it's
actually left over from the previous import of the pool.

This commit attempts to tackle that by setting a flag on the zvol if its
minor can't be removed, and then checking that flag when a request is
made and rejecting it, thus stopping new work coming in.

The flag also causes a condvar to be signaled when the last client
finishes. For the case where a single minor is being removed (eg
changing volmode), it will wait for this signal before proceeding.
Meanwhile, when removing all minors, a background task is created for
each minor that couldn't be removed on the spot, and those tasks then
wake and clean up.

Since any new tasks are queued on to the pool's spa_zvol_taskq,
spa_export_common() will continue to wait at export until all minors are
removed.

Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes #14872
Closes #16364
2024-08-06 12:08:14 -07:00
..
abd_os.c Linux: Report reclaimable memory to kernel as such (#16385) 2024-07-30 11:40:47 -07:00
arc_os.c Several improvements to ARC shrinking (#16197) 2024-07-25 10:31:14 -07:00
mmp_os.c Cleanup: 64-bit kernel module parameters should use fixed width types 2022-10-13 10:03:29 -07:00
policy.c Linux 6.3 compat: idmapped mount API changes 2023-04-10 14:15:36 -07:00
qat_compress.c Intel QAT 1.7 compatibility 2023-09-07 14:38:17 -07:00
qat_crypt.c Replace dead opensolaris.org license link 2022-07-11 14:16:13 -07:00
qat.c Replace dead opensolaris.org license link 2022-07-11 14:16:13 -07:00
spa_misc_os.c Selectable block allocators 2023-09-01 18:00:30 -07:00
trace.c Replace dead opensolaris.org license link 2022-07-11 14:16:13 -07:00
vdev_disk.c Linux 5.16: use bdev_nr_bytes() to get device capacity 2024-07-15 17:10:06 -07:00
vdev_file.c zio: rename ZIO_TYPE_IOCTL to ZIO_TYPE_FLUSH 2024-04-11 17:17:23 -07:00
vdev_label_os.c RAID-Z expansion feature 2023-11-08 10:19:41 -08:00
zfs_acl.c Fixed parameter passing error when calling zfs_acl_chmod 2024-02-26 11:41:44 -08:00
zfs_ctldir.c Linux 6.7 compat: use inode atime/mtime accessors 2023-12-20 11:47:40 -08:00
zfs_debug.c zdb/ztest: send dbgmsg output to stderr 2024-05-14 09:49:00 -07:00
zfs_dir.c Linux 6.3 compat: idmapped mount API changes 2023-04-10 14:15:36 -07:00
zfs_file_os.c Cleanup: Remove branches that always evaluate the same way 2022-11-03 10:47:48 -07:00
zfs_ioctl_os.c Linux 6.3 compat: idmapped mount API changes 2023-04-10 14:15:36 -07:00
zfs_racct.c module: zfs: fix unused, remove argsused 2021-12-23 09:42:47 -08:00
zfs_sysfs.c Introduce kmem_scnprintf() 2022-10-29 13:05:11 -07:00
zfs_uio.c Use kmap_local_page instead of kmap_atomic (#16329) 2024-07-16 17:27:29 -07:00
zfs_vfsops.c Linux 6.7 compat: handle superblock shrinker member change 2023-12-20 11:47:50 -08:00
zfs_vnops_os.c Fix corruption caused by mmap flushing problems 2024-03-25 14:56:49 -07:00
zfs_znode.c Linux: Report reclaimable memory to kernel as such (#16385) 2024-07-30 11:40:47 -07:00
zio_crypt.c ZIL: Assert record sizes in different places 2023-11-28 13:35:14 -08:00
zpl_ctldir.c Linux 6.6 compat: generic_fillattr has a new u32 request_mask added at arg2 2023-09-21 18:38:40 -07:00
zpl_export.c Replace dead opensolaris.org license link 2022-07-11 14:16:13 -07:00
zpl_file_range.c Linux 6.8 compat: use splice_copy_file_range() for fallback 2024-03-20 16:46:15 -07:00
zpl_file.c Fix corruption caused by mmap flushing problems 2024-03-25 14:56:49 -07:00
zpl_inode.c Linux 6.7 compat: use inode atime/mtime accessors 2023-12-20 11:47:40 -08:00
zpl_super.c Unify arc_prune_async() code 2023-10-30 16:56:04 -07:00
zpl_xattr.c Linux 6.6 compat: use inode_get/set_ctime*(...) 2023-09-21 18:38:31 -07:00
zvol_os.c zvol: ensure device minors are properly cleaned up 2024-08-06 12:08:14 -07:00