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authorTim Chase <[email protected]>2013-06-24 22:03:56 -0500
committerBrian Behlendorf <[email protected]>2013-07-01 14:51:45 -0700
commitab68b6e5db29abcd20c0c7b12a8c2fa570031c8b (patch)
treeb63560481a046181a28132572591f4e406d89701 /module
parent64d7b6cf75e52a4698d9bdec61745573c39d2e5a (diff)
Fix zfs_sb_teardown/zfs_resume_fs NULL dereference
Fix a pair of conditions in which a concurrent umount can cause NULL pointer dereferences: * zfs_sb_teardown - prevent a NULL dereference by not calling dmu_objset_pool with a null z_os. * zfs_resume_fs - don't try to unmount with a null z_os. This change makes the ZoL code more consistent with both Illumos and FreeBSD. Signed-off-by: Brian Behlendorf <[email protected]> Closes #1543
Diffstat (limited to 'module')
-rw-r--r--module/zfs/zfs_vfsops.c13
1 files changed, 8 insertions, 5 deletions
diff --git a/module/zfs/zfs_vfsops.c b/module/zfs/zfs_vfsops.c
index e618f2bbf..602c332ea 100644
--- a/module/zfs/zfs_vfsops.c
+++ b/module/zfs/zfs_vfsops.c
@@ -1056,10 +1056,12 @@ zfs_sb_teardown(zfs_sb_t *zsb, boolean_t unmounting)
}
/*
- * Drain the iput_taskq to ensure all active references to the
+ * If someone has not already unmounted this file system,
+ * drain the iput_taskq to ensure all active references to the
* zfs_sb_t have been handled only then can it be safely destroyed.
*/
- taskq_wait(dsl_pool_iput_taskq(dmu_objset_pool(zsb->z_os)));
+ if (zsb->z_os)
+ taskq_wait(dsl_pool_iput_taskq(dmu_objset_pool(zsb->z_os)));
/*
* Close the zil. NB: Can't close the zil while zfs_inactive
@@ -1480,10 +1482,11 @@ bail:
if (err) {
/*
- * Since we couldn't reopen zfs_sb_t, force
- * unmount this file system.
+ * Since we couldn't reopen zfs_sb_t or, setup the
+ * sa framework, force unmount this file system.
*/
- (void) zfs_umount(zsb->z_sb);
+ if (zsb->z_os)
+ (void) zfs_umount(zsb->z_sb);
}
return (err);
}