G_PROVIDER(9)

💖 G_PROVIDER(9) — the kernel dev manual, but make it cute 💖

okay bestie, gather round — this is the page for the GEOM providers management trio: g_new_providerf, g_destroy_provider, and g_error_provider. Kernel devs only, no cap. 🫶

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✨ NAME ✨

g_new_providerf, g_destroy_provider, g_error_provider — GEOM providers management 💅

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🌸 SYNOPSIS 🌸

#include <geom/geom.h>

struct g_provider *
g_new_providerf(struct g_geom *gp, const char *fmt, ...);

void
g_destroy_provider(struct g_provider *pp);

void
g_error_provider(struct g_provider *pp, int error);

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🦋 DESCRIPTION 🦋

So like, a GEOM provider is the front gate at which a geom offers service. Think of it as "a disk-like thing which appears in /dev" — a logical disk, in other words. 🌈 Every single provider has three main properties: name, sectorsize, and size. Those are the big three, the holy trinity, the main characters. 👑

g_new_providerf() — this one creates a new provider on the given geom gp. 🎀 The name of the provider, which is gonna show up as a device in devfs(5), gets built in a printf(3)-like way from the rest of the arguments. Very "fill in the blanks" of it. ✨

⚠️ But listen — after creation, the caller has to set the provider's mediasize and sectorsize, plus any other initializations it wants. Then it has to call g_error_provider() to reset the provider's error, which is initially set to ENXIO. Don't skip that step, bestie, it's giving unfinished business. 😭

g_destroy_provider() — destroys the given provider, cancels all related pending events, and removes the corresponding devfs entry. 🧹 Cleanup era. Bye bye, provider. 👋

g_error_provider() — used to set the provider's error value. 🚨 If you set it to a nonzero value, all I/O requests will be denied, and increasing its access count will not be possible either (the error you passed in will be returned). It's giving "we're closed, go home." 💀

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🔥 RESTRICTIONS/CONDITIONS 🔥

rules are rules, bestie, and these ones are non-negotiable fr fr

g_new_provider():

• The provider name should be unique, but this is not enforced by GEOM. 😳 If the name isn't unique, you'll end up with two (or more) files with the same name — and that is a programmer error.
• The geom gp has to have a start method defined. Periodt.
• The topology lock has to be held. 🔒

g_destroy_provider():

• The provider must not have consumers attached. 🙅
• The access count has to be 0.
• The topology lock has to be held. 🔒

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⭐ RETURN VALUES ⭐

The g_new_providerf() function returns a pointer to the newly created provider. That's it, that's the return value. 🎁

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🎀 EXAMPLES 🎀

Create an example provider, set its parameters, and make it usable. Iconic behavior, honestly.

struct g_provider *
create_example_provider(struct g_geom *gp)
{
        struct g_provider *pp;

        g_topology_lock();
        pp = g_new_providerf(gp, "example_provider");
        g_topology_unlock();
        pp->mediasize = 65536;
        pp->sectorsize = 512;
        g_error_provider(pp, 0);

        return (pp);
}

Look at her. Locked, created, unlocked, sized up, error reset, returned. 🌟 Ate and left no crumbs.

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👀 SEE ALSO 👀

geom(4), DECLARE_GEOM_CLASS(9), g_access(9), g_attach(9), g_bio(9), g_consumer(9), g_data(9), g_event(9), g_geom(9), g_provider_by_name(9), g_wither_geom(9)

iykyk — go read those next, the lore runs deep. 📚

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💜 AUTHORS 💜

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

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okay that's the whole page, you're officially a GEOM provider girlie now 💅✨ This little beauty comes to you from Debian, dated January 16, 2004 — yes, she's an elder but she still serves. 🎀🦋🌸 bye bestie, go hold that topology lock 💖