G_CONSUMER(9)

💖 G_CONSUMER(9) 💖

okay so bestie, welcome to G_CONSUMER(9) from the Kernel Developer's Manual — it's giving “niche kernel lore but make it cute” ✨. This page is literally about managing GEOM consumers, and yes, we're gonna keep every technical detail because the vibe check fails if the facts go missing. periodt 💅

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🎀 NAME 🎀

g_new_consumer, g_destroy_consumer — GEOM consumers management

✨ SYNOPSIS ✨

#include <geom/geom.h>

struct g_consumer *
g_new_consumer(struct g_geom *gp);

void
g_destroy_consumer(struct g_consumer *cp);

🦋 DESCRIPTION 🦋

okay so a GEOM consumer is the backdoor through which a geom connects to another GEOM provider and through which I/O requests are sent. main character energy, honestly 🔥.

The g_new_consumer() function creates a new consumer on geom gp. Before using the new consumer, it has to be attached to a provider with g_attach(9) and opened with g_access(9). no cap, those steps are required.

The g_destroy_consumer() function destroys the given consumer and cancels all related pending events. This function is the last stage of killing an unwanted consumer. bye-bye, consumer 👋.

🚨 RESTRICTIONS/CONDITIONS 🚨

🫶 g_new_consumer()

• The geom gp has to have an orphan method defined.
• The topology lock has to be held.

💅 g_destroy_consumer()

• The consumer must not be attached to a provider.
• The access count has to be 0.
• The topology lock has to be held.

🌈 RETURN VALUES 🌈

The g_new_consumer() function returns a pointer to the newly created consumer. that's it, that's the return value, bestie 💖.

🌸 EXAMPLES 🌸

Create consumer, attach it to given provider, gain read access and clean up.

             void
             some_function(struct g_geom *mygeom, struct g_provider *pp)
             {
                     struct g_consumer *cp;

                     g_topology_assert();

                     /* Create new consumer on 'mygeom' geom. */
                     cp = g_new_consumer(mygeom);
                     /* Attach newly created consumer to given provider. */
                     if (g_attach(cp, pp) != 0) {
                             g_destroy_consumer(cp);
                             return;
                     }
                     /* Open provider for reading through our consumer. */
                     if (g_access(cp, 1, 0, 0) != 0) {
                             g_detach(cp);
                             g_destroy_consumer(cp);
                             return;
                     }

                     g_topology_unlock();
                     /*
                      * Read data from provider.
                      */
                     g_topology_lock();

                     /* Disconnect from provider (release access count). */
                     g_access(cp, -1, 0, 0);
                     /* Detach from provider. */
                     g_detach(cp);
                     /* Destroy consumer. */
                     g_destroy_consumer(cp);
             }

👑 SEE ALSO 👑

• geom(4)
• DECLARE_GEOM_CLASS(9)
• g_access(9)
• g_attach(9)
• g_bio(9)
• g_data(9)
• g_event(9)
• g_geom(9)
• g_provider(9)
• g_provider_by_name(9)
• g_wither_geom(9)

🍓 AUTHORS 🍓

This manual page was written by Pawel Jakub Dawidek <pjd@FreeBSD.org>.

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and that's the whole page, bestie 🫶. this one came from Debian, dated January 16, 2004, and it's G_CONSUMER(9) 💅✨