Need a long hold in zpl_mount_impl

In zpl_mount_impl, there is:
    dmu_objset_hold	; returns with pool & ds held
    dsl_pool_rele

    sget

    dsl_dataset_rele

As spelled out in the "DSL Pool Configuration Lock" in dsl_pool.c,
this requires a long hold.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Paul Zuchowski <pzuchowski@datto.com>
Signed-off-by: John Poduska <jpoduska@datto.com>
Closes #10936
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John Poduska 2020-09-17 13:53:02 -04:00 committed by GitHub
parent 741b20ce0c
commit 5bed68bdc4
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@ -274,8 +274,12 @@ zpl_mount_impl(struct file_system_type *fs_type, int flags, zfs_mnt_t *zm)
* a txg sync. If the dsl_pool lock is held over sget()
* this can prevent the pool sync and cause a deadlock.
*/
dsl_dataset_long_hold(dmu_objset_ds(os), FTAG);
dsl_pool_rele(dmu_objset_pool(os), FTAG);
s = sget(fs_type, zpl_test_super, set_anon_super, flags, os);
dsl_dataset_long_rele(dmu_objset_ds(os), FTAG);
dsl_dataset_rele(dmu_objset_ds(os), FTAG);
if (IS_ERR(s))