Retry OCF ENOMEM errors in ZFS

[mav]

Summary

ZFS does not expect transient errors from crypto. For read they are counted as checksum errors, while for write end up in panic. To not panic on random low memory conditions retry ENOMEM errors in OCF wrapper function.

While there remove unneeded timeout and priority parameters from msleep().

[markj]

sys/contrib/openzfs/module/os/freebsd/zfs/crypto_os.c

177

BTW, the locking here and freebsd_zfs_crypt_done() is unnecessary for synchronous drivers like aesni. Same for the wakeup() call. You can check CRYPTO_SESS_SYNC(session->fs_sid) to determine if this is the case, if profiles suggest it is worth doing.

181

Presumably it should be else if.

193

This does not apply to the ENOMEM case, but I think it's harmless.

[asomers]

sys/contrib/openzfs/module/os/freebsd/zfs/crypto_os.c

180

You should probably continue after the pause, don't you think?

[mav]

sys/contrib/openzfs/module/os/freebsd/zfs/crypto_os.c

177

I haven't profiled this code very much, but I have suspect it won't be visible, comparing to cryptography.

180

No, I meant "else" there.

181

Yes. Thanks.