Processing TRIM requests in disk filter driver

[RRockhold]

I'm implementing a disk filter driver and am trying to intercept TRIM commands sent from NTFS to the SSD, but haven't been able to intercept any. I'm looking for an ATA TRIM command to come through via IOCTL_STORAGE_PROTOCOL_COMMAND, IOCTL_ATA_PASS_THROUGH or IOCTL_ATA_PASS_THROUGH_DIRECT, but haven't seen any.

To trigger TRIM, I'm creating (then deleting) a large file. I've also tried the "Defragment and Optimize Drives" and the Optimize-Volume cmdlet.

I've also verified that TRIM is enabled via fsutil.

Am I looking in the wrong place to intercept TRIM?

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