Was Gallipoli about Russia or the Ottoman Empire?

Was the primary objective to resupply Russia or knock the Ottoman Empire out of the war?

Both, but resupplying Russia was probably the larger objective because it kept a powerful eastern front in the war.

Knocking the Ottoman Empire out of the war would release Allied forces and transform the Balkans and Middle East. Reopening the Dardanelles would also restore the movement of food, exports, weapons, and industrial goods through Russia's Black Sea ports. Sustained supply to Russia ranks first because an equipped eastern ally preserves the two-front pressure that Germany could least afford. The distinction helps explain why Constantinople mattered as a logistical gateway as much as a political prize.