// SPDX-License-Identifier: GPL-2.0

#include <linux/ceph/ceph_debug.h>

#include <linux/module.h>
#include <linux/slab.h>

#include <linux/ceph/buffer.h>
#include <linux/ceph/decode.h>
#include <linux/ceph/libceph.h> /* for kvmalloc */

struct ceph_buffer *ceph_buffer_new(size_t len, gfp_t gfp)
{
        struct ceph_buffer *b;

        b = kmalloc_obj(*b, gfp);
        if (!b)
                return NULL;

        b->vec.iov_base = kvmalloc(len, gfp);
        if (!b->vec.iov_base) {
                kfree(b);
                return NULL;
        }

        kref_init(&b->kref);
        b->alloc_len = len;
        b->vec.iov_len = len;
        dout("buffer_new %p\n", b);
        return b;
}
EXPORT_SYMBOL(ceph_buffer_new);

void ceph_buffer_release(struct kref *kref)
{
        struct ceph_buffer *b = container_of(kref, struct ceph_buffer, kref);

        dout("buffer_release %p\n", b);
        kvfree(b->vec.iov_base);
        kfree(b);
}
EXPORT_SYMBOL(ceph_buffer_release);

int ceph_decode_buffer(struct ceph_buffer **b, void **p, void *end)
{
        size_t len;

        ceph_decode_need(p, end, sizeof(u32), bad);
        len = ceph_decode_32(p);
        dout("decode_buffer len %d\n", (int)len);
        ceph_decode_need(p, end, len, bad);
        *b = ceph_buffer_new(len, GFP_NOFS);
        if (!*b)
                return -ENOMEM;
        ceph_decode_copy(p, (*b)->vec.iov_base, len);
        return 0;
bad:
        return -EINVAL;
}