ceph/src/os/filestore/chain_xattr.h

   1 // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
   2 // vim: ts=8 sw=2 smarttab
   3
   4 #ifndef __CEPH_OSD_CHAIN_XATTR_H
   5 #define __CEPH_OSD_CHAIN_XATTR_H
   6
   7 #include "include/compat.h"
   8 #include <errno.h>
   9 #include <stdio.h>
  10 #include "os_xattr.h"
  11 #include "include/ceph_assert.h"
  12 #include "include/buffer_fwd.h"
  13
  14 #if defined(__linux__)
  15 #include <linux/limits.h>
  16 #define CHAIN_XATTR_MAX_NAME_LEN ((XATTR_NAME_MAX + 1) / 2)
  17 #elif defined(__APPLE__)
  18 #include <sys/xattr.h>
  19 #define CHAIN_XATTR_MAX_NAME_LEN ((XATTR_MAXNAMELEN + 1) / 2)
  20 #else
  21 #define CHAIN_XATTR_MAX_NAME_LEN  128
  22 #endif
  23
  24 #define CHAIN_XATTR_MAX_BLOCK_LEN 2048
  25
  26 /*
  27  * XFS will only inline xattrs < 255 bytes, so for xattrs that are
  28  * likely to fit in the inode, stripe over short xattrs.
  29  */
  30 #define CHAIN_XATTR_SHORT_BLOCK_LEN 250
  31 #define CHAIN_XATTR_SHORT_LEN_THRESHOLD 1000
  32
  33 // wrappers to hide annoying errno handling.
  34
  35 inline int sys_fgetxattr(int fd, const char *name, void *val, size_t size)
  36 {
  37   int r = ::ceph_os_fgetxattr(fd, name, val, size);
  38   return (r < 0 ? -errno : r);
  39 }
  40 inline int sys_getxattr(const char *fn, const char *name, void *val, size_t size)
  41 {
  42   int r = ::ceph_os_getxattr(fn, name, val, size);
  43   return (r < 0 ? -errno : r);
  44 }
  45
  46 inline int sys_setxattr(const char *fn, const char *name, const void *val, size_t size)
  47 {
  48   int r = ::ceph_os_setxattr(fn, name, val, size);
  49   return (r < 0 ? -errno : r);
  50 }
  51 inline int sys_fsetxattr(int fd, const char *name, const void *val, size_t size)
  52 {
  53   int r = ::ceph_os_fsetxattr(fd, name, val, size);
  54   return (r < 0 ? -errno : r);
  55 }
  56
  57 inline int sys_listxattr(const char *fn, char *names, size_t len)
  58 {
  59   int r = ::ceph_os_listxattr(fn, names, len);
  60   return (r < 0 ? -errno : r);
  61 }
  62 inline int sys_flistxattr(int fd, char *names, size_t len)
  63 {
  64   int r = ::ceph_os_flistxattr(fd, names, len);
  65   return (r < 0 ? -errno : r);
  66 }
  67
  68 inline int sys_removexattr(const char *fn, const char *name)
  69 {
  70   int r = ::ceph_os_removexattr(fn, name);
  71   return (r < 0 ? -errno : r);
  72 }
  73 inline int sys_fremovexattr(int fd, const char *name)
  74 {
  75   int r = ::ceph_os_fremovexattr(fd, name);
  76   return (r < 0 ? -errno : r);
  77 }
  78
  79
  80 // wrappers to chain large values across multiple xattrs
  81
  82 int chain_getxattr(const char *fn, const char *name, void *val, size_t size);
  83 int chain_getxattr_buf(const char *fn, const char *name, ceph::buffer::ptr *bp);
  84 int chain_fgetxattr(int fd, const char *name, void *val, size_t size);
  85
  86 int get_xattr_block_size(size_t size);
  87 void get_raw_xattr_name(const char *name, int i, char *raw_name, int raw_len);
  88
  89 template <bool skip_chain_cleanup=false, bool ensure_single_attr=false>
  90 int chain_setxattr(
  91   const char *fn, const char *name, const void *val, size_t size)
  92 {
  93   int i = 0, pos = 0;
  94   char raw_name[CHAIN_XATTR_MAX_NAME_LEN * 2 + 16];
  95   int ret = 0;
  96   size_t max_chunk_size =
  97     ensure_single_attr ? size : get_xattr_block_size(size);
  98
  99   static_assert(
 100     !skip_chain_cleanup || ensure_single_attr,
 101     "skip_chain_cleanup must imply ensure_single_attr");
 102
 103   do {
 104     size_t chunk_size = (size < max_chunk_size ? size : max_chunk_size);
 105     get_raw_xattr_name(name, i, raw_name, sizeof(raw_name));
 106     size -= chunk_size;
 107
 108     int r = sys_setxattr(fn, raw_name, (char *)val + pos, chunk_size);
 109     if (r < 0) {
 110       ret = r;
 111       break;
 112     }
 113     pos  += chunk_size;
 114     ret = pos;
 115     i++;
 116     ceph_assert(size == 0 || !ensure_single_attr);
 117   } while (size);
 118
 119   if (ret >= 0 && !skip_chain_cleanup) {
 120     int r;
 121     do {
 122       get_raw_xattr_name(name, i, raw_name, sizeof(raw_name));
 123       r = sys_removexattr(fn, raw_name);
 124       if (r < 0 && r != -ENODATA)
 125         ret = r;
 126       i++;
 127     } while (r != -ENODATA);
 128   }
 129
 130   return ret;
 131 }
 132
 133 template <bool skip_chain_cleanup=false, bool ensure_single_attr=false>
 134 int chain_fsetxattr(
 135   int fd, const char *name, const void *val, size_t size)
 136 {
 137   int i = 0, pos = 0;
 138   char raw_name[CHAIN_XATTR_MAX_NAME_LEN * 2 + 16];
 139   int ret = 0;
 140   size_t max_chunk_size =
 141     ensure_single_attr ? size : get_xattr_block_size(size);
 142
 143   static_assert(
 144     !skip_chain_cleanup || ensure_single_attr,
 145     "skip_chain_cleanup must imply ensure_single_attr");
 146
 147   do {
 148     size_t chunk_size = (size < max_chunk_size ? size : max_chunk_size);
 149     get_raw_xattr_name(name, i, raw_name, sizeof(raw_name));
 150     size -= chunk_size;
 151
 152     int r = sys_fsetxattr(fd, raw_name, (char *)val + pos, chunk_size);
 153     if (r < 0) {
 154       ret = r;
 155       break;
 156     }
 157     pos  += chunk_size;
 158     ret = pos;
 159     i++;
 160     ceph_assert(size == 0 || !ensure_single_attr);
 161   } while (size);
 162
 163   if (ret >= 0 && !skip_chain_cleanup) {
 164     int r;
 165     do {
 166       get_raw_xattr_name(name, i, raw_name, sizeof(raw_name));
 167       r = sys_fremovexattr(fd, raw_name);
 168       if (r < 0 && r != -ENODATA)
 169         ret = r;
 170       i++;
 171     } while (r != -ENODATA);
 172   }
 173
 174   return ret;
 175 }
 176
 177 int chain_listxattr(const char *fn, char *names, size_t len);
 178 int chain_flistxattr(int fd, char *names, size_t len);
 179 int chain_removexattr(const char *fn, const char *name);
 180 int chain_fremovexattr(int fd, const char *name);
 181
 182 #endif