fs/ceph/buffer.c

   1
   2 #include "ceph_debug.h"
   3
   4 #include <linux/slab.h>
   5
   6 #include "buffer.h"
   7 #include "decode.h"
   8
   9 struct ceph_buffer *ceph_buffer_new(size_t len, gfp_t gfp)
  10 {
  11         struct ceph_buffer *b;
  12
  13         b = kmalloc(sizeof(*b), gfp);
  14         if (!b)
  15                 return NULL;
  16
  17         b->vec.iov_base = kmalloc(len, gfp | __GFP_NOWARN);
  18         if (b->vec.iov_base) {
  19                 b->is_vmalloc = false;
  20         } else {
  21                 b->vec.iov_base = __vmalloc(len, gfp, PAGE_KERNEL);
  22                 if (!b->vec.iov_base) {
  23                         kfree(b);
  24                         return NULL;
  25                 }
  26                 b->is_vmalloc = true;
  27         }
  28
  29         kref_init(&b->kref);
  30         b->alloc_len = len;
  31         b->vec.iov_len = len;
  32         dout("buffer_new %p\n", b);
  33         return b;
  34 }
  35
  36 void ceph_buffer_release(struct kref *kref)
  37 {
  38         struct ceph_buffer *b = container_of(kref, struct ceph_buffer, kref);
  39
  40         dout("buffer_release %p\n", b);
  41         if (b->vec.iov_base) {
  42                 if (b->is_vmalloc)
  43                         vfree(b->vec.iov_base);
  44                 else
  45                         kfree(b->vec.iov_base);
  46         }
  47         kfree(b);
  48 }
  49
  50 int ceph_buffer_alloc(struct ceph_buffer *b, int len, gfp_t gfp)
  51 {
  52         b->vec.iov_base = kmalloc(len, gfp | __GFP_NOWARN);
  53         if (b->vec.iov_base) {
  54                 b->is_vmalloc = false;
  55         } else {
  56                 b->vec.iov_base = __vmalloc(len, gfp, PAGE_KERNEL);
  57                 b->is_vmalloc = true;
  58         }
  59         if (!b->vec.iov_base)
  60                 return -ENOMEM;
  61         b->alloc_len = len;
  62         b->vec.iov_len = len;
  63         return 0;
  64 }
  65
  66 int ceph_decode_buffer(struct ceph_buffer **b, void **p, void *end)
  67 {
  68         size_t len;
  69
  70         ceph_decode_need(p, end, sizeof(u32), bad);
  71         len = ceph_decode_32(p);
  72         dout("decode_buffer len %d\n", (int)len);
  73         ceph_decode_need(p, end, len, bad);
  74         *b = ceph_buffer_new(len, GFP_NOFS);
  75         if (!*b)
  76                 return -ENOMEM;
  77         ceph_decode_copy(p, (*b)->vec.iov_base, len);
  78         return 0;
  79 bad:
  80         return -EINVAL;
  81 }