buffer.c

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#include <linux/ceph/ceph_debug.h>

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

#include <linux/ceph/buffer.h>
#include <linux/ceph/decode.h>

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

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

    b->vec.iov_base = kmalloc(len, gfp | __GFP_NOWARN);
    if (b->vec.iov_base) {
        b->is_vmalloc = false;
    } else {
        b->vec.iov_base = __vmalloc(len, gfp | __GFP_HIGHMEM, PAGE_KERNEL);
        if (!b->vec.iov_base) {
            kfree(b);
            return NULL;
        }
        b->is_vmalloc = true;
    }

    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);
    if (b->vec.iov_base) {
        if (b->is_vmalloc)
            vfree(b->vec.iov_base);
        else
            kfree(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;
}