mirror_zfs/module/os/freebsd/zfs
rob-wing f786232b2a FreeBSD: don't verify recycled vnode for zfs control directory
Under certain loads, the following panic is hit:

    panic: page fault
    KDB: stack backtrace:
    #0 0xffffffff805db025 at kdb_backtrace+0x65
    #1 0xffffffff8058e86f at vpanic+0x17f
    #2 0xffffffff8058e6e3 at panic+0x43
    #3 0xffffffff808adc15 at trap_fatal+0x385
    #4 0xffffffff808adc6f at trap_pfault+0x4f
    #5 0xffffffff80886da8 at calltrap+0x8
    #6 0xffffffff80669186 at vgonel+0x186
    #7 0xffffffff80669841 at vgone+0x31
    #8 0xffffffff8065806d at vfs_hash_insert+0x26d
    #9 0xffffffff81a39069 at sfs_vgetx+0x149
    #10 0xffffffff81a39c54 at zfsctl_snapdir_lookup+0x1e4
    #11 0xffffffff8065a28c at lookup+0x45c
    #12 0xffffffff806594b9 at namei+0x259
    #13 0xffffffff80676a33 at kern_statat+0xf3
    #14 0xffffffff8067712f at sys_fstatat+0x2f
    #15 0xffffffff808ae50c at amd64_syscall+0x10c
    #16 0xffffffff808876bb at fast_syscall_common+0xf8

The page fault occurs because vgonel() will call VOP_CLOSE() for active
vnodes. For this reason, define vop_close for zfsctl_ops_snapshot. While
here, define vop_open for consistency.

After adding the necessary vop, the bug progresses to the following
panic:

    panic: VERIFY3(vrecycle(vp) == 1) failed (0 == 1)
    cpuid = 17
    KDB: stack backtrace:
    #0 0xffffffff805e29c5 at kdb_backtrace+0x65
    #1 0xffffffff8059620f at vpanic+0x17f
    #2 0xffffffff81a27f4a at spl_panic+0x3a
    #3 0xffffffff81a3a4d0 at zfsctl_snapshot_inactive+0x40
    #4 0xffffffff8066fdee at vinactivef+0xde
    #5 0xffffffff80670b8a at vgonel+0x1ea
    #6 0xffffffff806711e1 at vgone+0x31
    #7 0xffffffff8065fa0d at vfs_hash_insert+0x26d
    #8 0xffffffff81a39069 at sfs_vgetx+0x149
    #9 0xffffffff81a39c54 at zfsctl_snapdir_lookup+0x1e4
    #10 0xffffffff80661c2c at lookup+0x45c
    #11 0xffffffff80660e59 at namei+0x259
    #12 0xffffffff8067e3d3 at kern_statat+0xf3
    #13 0xffffffff8067eacf at sys_fstatat+0x2f
    #14 0xffffffff808b5ecc at amd64_syscall+0x10c
    #15 0xffffffff8088f07b at fast_syscall_common+0xf8

This is caused by a race condition that can occur when allocating a new
vnode and adding that vnode to the vfs hash. If the newly created vnode
loses the race when being inserted into the vfs hash, it will not be
recycled as its usecount is greater than zero, hitting the above
assertion.

Fix this by dropping the assertion.

FreeBSD-issue: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=252700
Reviewed-by: Andriy Gapon <avg@FreeBSD.org>
Reviewed-by: Mateusz Guzik <mjguzik@gmail.com>
Reviewed-by: Alek Pinchuk <apinchuk@axcient.com>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Rob Wing <rob.wing@klarasystems.com>
Co-authored-by: Rob Wing <rob.wing@klarasystems.com>
Submitted-by: Klara, Inc.
Sponsored-by: rsync.net
Closes #14501
2023-05-30 08:53:21 -07:00
..
abd_os.c Avoid small buffer copying on write 2022-07-26 10:10:37 -07:00
arc_os.c FreeBSD: Remove extra arc_reduce_target_size() call 2023-03-24 12:27:52 -05:00
crypto_os.c FreeBSD: Improve crypto_dispatch() handling 2022-07-26 10:10:37 -07:00
dmu_os.c FreeBSD: Clean up ASSERT/VERIFY use in module 2021-09-14 12:02:23 -07:00
hkdf.c
kmod_core.c FreeBSD: Remove stray debug printf 2023-01-19 12:50:36 -08:00
spa_os.c FreeBSD: Fix potential boot panic with bad label 2023-01-05 11:00:09 -08:00
sysctl_os.c Turn default_bs and default_ibs into ZFS_MODULE_PARAMs 2023-03-07 13:58:36 -08:00
vdev_file.c module: zfs: fix unused, remove argsused 2022-02-16 17:58:56 -08:00
vdev_geom.c Improve too large physical ashift handling 2022-09-21 13:15:15 -07:00
vdev_label_os.c FreeBSD: Clean up ASSERT/VERIFY use in module 2021-09-14 12:02:23 -07:00
zfs_acl.c Fix ACL checks for NFS kernel server 2022-03-20 21:21:18 -07:00
zfs_ctldir.c FreeBSD: don't verify recycled vnode for zfs control directory 2023-05-30 08:53:21 -07:00
zfs_debug.c Annotated dprintf as printf-like 2021-06-24 13:12:36 -07:00
zfs_dir.c FreeBSD: Clean up ASSERT/VERIFY use in module 2021-09-14 12:02:23 -07:00
zfs_file_os.c FreeBSD: handle V_PCATCH 2022-09-28 10:35:13 -07:00
zfs_ioctl_compat.c FreeBSD: Fix out of bounds read in zfs_ioctl_ozfs_to_legacy() 2022-12-01 12:39:43 -08:00
zfs_ioctl_os.c FreeBSD: make zfs_vfs_held() definition consistent with declaration 2023-05-30 08:53:21 -07:00
zfs_racct.c module: zfs: fix unused, remove argsused 2022-02-16 17:58:56 -08:00
zfs_vfsops.c Avoid a null pointer dereference in zfs_mount() on FreeBSD 2023-02-06 10:40:16 -08:00
zfs_vnops_os.c FreeBSD: catch up to 1400068 2022-09-28 10:35:13 -07:00
zfs_znode.c FreeBSD: catch up to 1400077 2023-01-19 12:50:42 -08:00
zio_crypt.c module: zfs: fix unused, remove argsused 2022-02-16 17:58:56 -08:00
zvol_os.c Additional limits on hole reporting 2023-03-29 10:40:49 -07:00