mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-13 14:04:05 +08:00
c30dbb9cc7
struct ceph_buffer is a simple ref-counted buffer. We transparently choose between kmalloc for small buffers and vmalloc for large ones. This is currently used only for allocating memory for xattr data. Signed-off-by: Sage Weil <sage@newdream.net>
56 lines
1.0 KiB
C
56 lines
1.0 KiB
C
#ifndef __FS_CEPH_BUFFER_H
|
|
#define __FS_CEPH_BUFFER_H
|
|
|
|
#include <linux/mm.h>
|
|
#include <linux/vmalloc.h>
|
|
#include <linux/types.h>
|
|
#include <linux/uio.h>
|
|
|
|
/*
|
|
* a simple reference counted buffer.
|
|
*
|
|
* use kmalloc for small sizes (<= one page), vmalloc for larger
|
|
* sizes.
|
|
*/
|
|
struct ceph_buffer {
|
|
atomic_t nref;
|
|
struct kvec vec;
|
|
size_t alloc_len;
|
|
bool is_vmalloc;
|
|
};
|
|
|
|
struct ceph_buffer *ceph_buffer_new(gfp_t gfp);
|
|
int ceph_buffer_alloc(struct ceph_buffer *b, int len, gfp_t gfp);
|
|
|
|
static inline struct ceph_buffer *ceph_buffer_get(struct ceph_buffer *b)
|
|
{
|
|
atomic_inc(&b->nref);
|
|
return b;
|
|
}
|
|
|
|
static inline void ceph_buffer_put(struct ceph_buffer *b)
|
|
{
|
|
if (b && atomic_dec_and_test(&b->nref)) {
|
|
if (b->vec.iov_base) {
|
|
if (b->is_vmalloc)
|
|
vfree(b->vec.iov_base);
|
|
else
|
|
kfree(b->vec.iov_base);
|
|
}
|
|
kfree(b);
|
|
}
|
|
}
|
|
|
|
static inline struct ceph_buffer *ceph_buffer_new_alloc(int len, gfp_t gfp)
|
|
{
|
|
struct ceph_buffer *b = ceph_buffer_new(gfp);
|
|
|
|
if (b && ceph_buffer_alloc(b, len, gfp) < 0) {
|
|
ceph_buffer_put(b);
|
|
b = NULL;
|
|
}
|
|
return b;
|
|
}
|
|
|
|
#endif
|