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| author | Andy Fiddaman <omnios@citrus-it.co.uk> | 2020-05-22 16:20:54 +0000 |
|---|---|---|
| committer | Andy Fiddaman <omnios@citrus-it.co.uk> | 2020-06-01 23:23:46 +0000 |
| commit | b39b008f8a57ea7ddfd0f69b24529deba7c25ae1 (patch) | |
| tree | e94251ef48b1fcaa5ac9f0490ffbc29b3527d408 | |
| parent | 94bce860c16a04a3d8eaeaa18807723c026e23b5 (diff) | |
| download | illumos-joyent-b39b008f8a57ea7ddfd0f69b24529deba7c25ae1.tar.gz | |
12783 async unlinked drain races with ZFS unmount
Reviewed by: Jerry Jelinek <jerry.jelinek@joyent.com>
Reviewed by: Joshua M. Clulow <josh@sysmgr.org>
Reviewed by: Jason King <jason.king@joyent.com>
Approved by: Robert Mustacchi <rm@fingolfin.org>
| -rw-r--r-- | usr/src/uts/common/fs/zfs/zfs_vfsops.c | 39 |
1 files changed, 28 insertions, 11 deletions
diff --git a/usr/src/uts/common/fs/zfs/zfs_vfsops.c b/usr/src/uts/common/fs/zfs/zfs_vfsops.c index d504e15457..9e2758aab0 100644 --- a/usr/src/uts/common/fs/zfs/zfs_vfsops.c +++ b/usr/src/uts/common/fs/zfs/zfs_vfsops.c @@ -25,6 +25,7 @@ * Copyright 2016 Nexenta Systems, Inc. All rights reserved. * Copyright 2019 Joyent, Inc. * Copyright 2020 Joshua M. Clulow <josh@sysmgr.org> + * Copyright 2020 OmniOS Community Edition (OmniOSce) Association. */ /* Portions Copyright 2010 Robert Milkowski */ @@ -2228,18 +2229,34 @@ zfs_umount(vfs_t *vfsp, int fflag, cred_t *cr) * Our count is maintained in the vfs structure, but the * number is off by 1 to indicate a hold on the vfs * structure itself. - * - * The '.zfs' directory maintains a reference of its - * own, and any active references underneath are - * reflected in the vnode count. */ - if (zfsvfs->z_ctldir == NULL) { - if (vfsp->vfs_count > 1) - return (SET_ERROR(EBUSY)); - } else { - if (vfsp->vfs_count > 2 || - zfsvfs->z_ctldir->v_count > 1) - return (SET_ERROR(EBUSY)); + boolean_t draining; + uint_t thresh = 1; + + /* + * The '.zfs' directory maintains a reference of its own, and + * any active references underneath are reflected in the vnode + * count. Allow one additional reference for it. + */ + if (zfsvfs->z_ctldir != NULL) + thresh++; + + /* + * If it's running, the asynchronous unlinked drain task needs + * to be stopped before the number of active vnodes can be + * reliably checked. + */ + draining = zfsvfs->z_draining; + if (draining) + zfs_unlinked_drain_stop_wait(zfsvfs); + + if (vfsp->vfs_count > thresh || (zfsvfs->z_ctldir != NULL && + zfsvfs->z_ctldir->v_count > 1)) { + if (draining) { + /* If it was draining, restart the task */ + zfs_unlinked_drain(zfsvfs); + } + return (SET_ERROR(EBUSY)); } } |