MFC r309097: MFV r308987: 7180 potential race between

zfs_suspend_fs+zfs_resume_fs and zfs_ioc_rename

3 files changed, 18 insertions, 11 deletions

diff --git a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/zfs_vfsops.h b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/zfs_vfsops.h
index df5ce05..bcf22cd 100644
--- a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/zfs_vfsops.h
+++ b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/zfs_vfsops.h
@@ -142,7 +142,7 @@ extern uint_t zfs_fsyncer_key;
 extern int zfs_super_owner;
 
 extern int zfs_suspend_fs(zfsvfs_t *zfsvfs);
-extern int zfs_resume_fs(zfsvfs_t *zfsvfs, const char *osname);
+extern int zfs_resume_fs(zfsvfs_t *zfsvfs, struct dsl_dataset *ds);
 extern int zfs_userspace_one(zfsvfs_t *zfsvfs, zfs_userquota_prop_t type,
     const char *domain, uint64_t rid, uint64_t *valuep);
 extern int zfs_userspace_many(zfsvfs_t *zfsvfs, zfs_userquota_prop_t type,
diff --git a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_ioctl.c b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_ioctl.c
index 52b9c83..0e2ba77 100644
--- a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_ioctl.c
+++ b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_ioctl.c
@@ -3788,12 +3788,15 @@ zfs_ioc_rollback(const char *fsname, nvlist_t *args, nvlist_t *outnvl)
 	int error;
 
 	if (getzfsvfs(fsname, &zfsvfs) == 0) {
+		dsl_dataset_t *ds;
+
+		ds = dmu_objset_ds(zfsvfs->z_os);
 		error = zfs_suspend_fs(zfsvfs);
 		if (error == 0) {
 			int resume_err;
 
 			error = dsl_dataset_rollback(fsname, zfsvfs, outnvl);
-			resume_err = zfs_resume_fs(zfsvfs, fsname);
+			resume_err = zfs_resume_fs(zfsvfs, ds);
 			error = error ? error : resume_err;
 		}
 #ifdef illumos
@@ -4444,8 +4447,10 @@ zfs_ioc_recv(zfs_cmd_t *zc)
 
 		if (getzfsvfs(tofs, &zfsvfs) == 0) {
 			/* online recv */
+			dsl_dataset_t *ds;
 			int end_err;
 
+			ds = dmu_objset_ds(zfsvfs->z_os);
 			error = zfs_suspend_fs(zfsvfs);
 			/*
 			 * If the suspend fails, then the recv_end will
@@ -4453,7 +4458,7 @@ zfs_ioc_recv(zfs_cmd_t *zc)
 			 */
 			end_err = dmu_recv_end(&drc, zfsvfs);
 			if (error == 0)
-				error = zfs_resume_fs(zfsvfs, tofs);
+				error = zfs_resume_fs(zfsvfs, ds);
 			error = error ? error : end_err;
 #ifdef illumos
 			VFS_RELE(zfsvfs->z_vfs);
@@ -4999,11 +5004,14 @@ zfs_ioc_userspace_upgrade(zfs_cmd_t *zc)
 			 * objset needs to be closed & reopened (to grow the
 			 * objset_phys_t).  Suspend/resume the fs will do that.
 			 */
+			dsl_dataset_t *ds;
+
+			ds = dmu_objset_ds(zfsvfs->z_os);
 			error = zfs_suspend_fs(zfsvfs);
 			if (error == 0) {
 				dmu_objset_refresh_ownership(zfsvfs->z_os,
 				    zfsvfs);
-				error = zfs_resume_fs(zfsvfs, zc->zc_name);
+				error = zfs_resume_fs(zfsvfs, ds);
 			}
 		}
 		if (error == 0)
diff --git a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vfsops.c b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vfsops.c
index fbaa324..ffc5f57 100644
--- a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vfsops.c
+++ b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vfsops.c
@@ -2225,7 +2225,7 @@ zfs_suspend_fs(zfsvfs_t *zfsvfs)
  * zfsvfs, held, and long held on entry.
  */
 int
-zfs_resume_fs(zfsvfs_t *zfsvfs, const char *osname)
+zfs_resume_fs(zfsvfs_t *zfsvfs, dsl_dataset_t *ds)
 {
 	int err;
 	znode_t *zp;
@@ -2234,14 +2234,13 @@ zfs_resume_fs(zfsvfs_t *zfsvfs, const char *osname)
 	ASSERT(RW_WRITE_HELD(&zfsvfs->z_teardown_inactive_lock));
 
 	/*
-	 * We already own this, so just hold and rele it to update the
-	 * objset_t, as the one we had before may have been evicted.
+	 * We already own this, so just update the objset_t, as the one we
+	 * had before may have been evicted.
 	 */
 	objset_t *os;
-	VERIFY0(dmu_objset_hold(osname, zfsvfs, &os));
-	VERIFY3P(os->os_dsl_dataset->ds_owner, ==, zfsvfs);
-	VERIFY(dsl_dataset_long_held(os->os_dsl_dataset));
-	dmu_objset_rele(os, zfsvfs);
+	VERIFY3P(ds->ds_owner, ==, zfsvfs);
+	VERIFY(dsl_dataset_long_held(ds));
+	VERIFY0(dmu_objset_from_ds(ds, &os));
 
 	err = zfsvfs_init(zfsvfs, os);
 	if (err != 0)