fs/ceph/buffer.c

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