plugins/vddk/vddk.h

   1 /* nbdkit
   2  * Copyright Red Hat
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions are
   6  * met:
   7  *
   8  * * Redistributions of source code must retain the above copyright
   9  * notice, this list of conditions and the following disclaimer.
  10  *
  11  * * Redistributions in binary form must reproduce the above copyright
  12  * notice, this list of conditions and the following disclaimer in the
  13  * documentation and/or other materials provided with the distribution.
  14  *
  15  * * Neither the name of Red Hat nor the names of its contributors may be
  16  * used to endorse or promote products derived from this software without
  17  * specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  21  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
  22  * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR
  23  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  24  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  25  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
  26  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  27  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  28  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  29  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32
  33 #ifndef NBDKIT_VDDK_H
  34 #define NBDKIT_VDDK_H
  35
  36 #include <stdbool.h>
  37 #include <stdint.h>
  38 #include <sys/time.h>
  39
  40 #include <pthread.h>
  41
  42 #include "isaligned.h"
  43 #include "tvdiff.h"
  44 #include "vector.h"
  45
  46 #include "vddk-structs.h"
  47
  48 enum compression_type { NONE = 0, ZLIB, FASTLZ, SKIPZ };
  49
  50 extern void *dl;
  51 extern bool init_called;
  52 extern __thread int error_suppression;
  53 extern int library_version;
  54 extern bool is_remote;
  55
  56 extern enum compression_type compression;
  57 extern char *config;
  58 extern const char *cookie;
  59 extern bool create;
  60 extern enum VixDiskLibAdapterType create_adapter_type;
  61 extern uint16_t create_hwversion;
  62 extern uint64_t create_size;
  63 extern enum VixDiskLibDiskType create_type;
  64 extern const char *filename;
  65 extern char *libdir;
  66 extern uint16_t nfc_host_port;
  67 extern char *password;
  68 extern uint16_t port;
  69 extern const char *server_name;
  70 extern bool single_link;
  71 extern const char *snapshot_moref;
  72 extern const char *thumb_print;
  73 extern const char *transport_modes;
  74 extern bool unbuffered;
  75 extern const char *username;
  76 extern const char *vmx_spec;
  77
  78 extern int vddk_debug_diskinfo;
  79 extern int vddk_debug_extents;
  80 extern int vddk_debug_datapath;
  81 extern int vddk_debug_stats;
  82
  83 #define STUB(fn, ret, args) extern ret (*fn) args
  84 #define OPTIONAL_STUB(fn, ret, args) STUB (fn, ret, args)
  85 #include "vddk-stubs.h"
  86 #undef STUB
  87 #undef OPTIONAL_STUB
  88
  89 /* Macros to bracket each VDDK API call, for printing debugging
  90  * information and collecting statistics.
  91  */
  92 #define VDDK_CALL_START(fn, fs, ...)                                    \
  93   do {                                                                  \
  94   struct timeval start_t, end_t;                                        \
  95   /* GCC can optimize this away at compile time: */                     \
  96   const bool datapath =                                                 \
  97     strcmp (#fn, "VixDiskLib_Read") == 0 ||                             \
  98     strcmp (#fn, "VixDiskLib_ReadAsync") == 0 ||                        \
  99     strcmp (#fn, "VixDiskLib_Write") == 0 ||                            \
 100     strcmp (#fn, "VixDiskLib_WriteAsync") == 0;                         \
 101   if (vddk_debug_stats)                                                 \
 102     gettimeofday (&start_t, NULL);                                      \
 103   if (!datapath || vddk_debug_datapath)                                 \
 104     nbdkit_debug ("VDDK call: %s (" fs ")", #fn, ##__VA_ARGS__);        \
 105   do
 106 #define VDDK_CALL_END(fn, bytes_)                       \
 107   while (0);                                            \
 108   if (vddk_debug_stats) {                               \
 109     gettimeofday (&end_t, NULL);                        \
 110     ACQUIRE_LOCK_FOR_CURRENT_SCOPE (&stats_lock);       \
 111     stats_##fn.usecs += tvdiff_usec (&start_t, &end_t); \
 112     stats_##fn.calls++;                                 \
 113     stats_##fn.bytes += bytes_;                         \
 114   }                                                     \
 115   } while (0)
 116
 117 /* Print VDDK errors. */
 118 #define VDDK_ERROR(err, fs, ...)                                \
 119   do {                                                          \
 120     char *vddk_err_msg;                                         \
 121     VDDK_CALL_START (VixDiskLib_GetErrorText, "%lu", err)       \
 122       vddk_err_msg = VixDiskLib_GetErrorText ((err), NULL);     \
 123     VDDK_CALL_END (VixDiskLib_GetErrorText, 0);                 \
 124     nbdkit_error (fs ": %s", ##__VA_ARGS__, vddk_err_msg);      \
 125     VDDK_CALL_START (VixDiskLib_FreeErrorText, "")              \
 126       VixDiskLib_FreeErrorText (vddk_err_msg);                  \
 127     VDDK_CALL_END (VixDiskLib_FreeErrorText, 0);                \
 128   } while (0)
 129
 130 /* Queue of asynchronous commands sent to the background thread. */
 131 enum command_type { INFO, READ, WRITE, FLUSH, CAN_EXTENTS, EXTENTS, STOP };
 132 struct command {
 133   /* These fields are set by the caller. */
 134   enum command_type type;       /* command */
 135   void *ptr;                    /* buffer, extents list, return values */
 136   uint32_t count;               /* READ, WRITE, EXTENTS */
 137   uint64_t offset;              /* READ, WRITE, EXTENTS */
 138   bool req_one;                 /* EXTENTS NBDKIT_FLAG_REQ_ONE */
 139
 140   /* This field is set to a unique value by send_command_and_wait. */
 141   uint64_t id;                  /* serial number */
 142
 143   /* These fields are used by the internal implementation. */
 144   pthread_mutex_t mutex;        /* completion mutex */
 145   pthread_cond_t cond;          /* completion condition */
 146   enum { SUBMITTED, SUCCEEDED, FAILED } status;
 147 };
 148
 149 DEFINE_VECTOR_TYPE (command_queue, struct command *);
 150
 151 /* The per-connection handle. */
 152 struct vddk_handle {
 153   VixDiskLibConnectParams *params; /* connection parameters */
 154   VixDiskLibConnection connection; /* connection */
 155   VixDiskLibHandle handle;         /* disk handle */
 156
 157   pthread_t thread;                /* background thread for asynch work */
 158
 159   /* Command queue of commands sent to the background thread.  Use
 160    * send_command_and_wait to add a command.  Only the background
 161    * thread must make VDDK API calls (apart from opening and closing).
 162    * The lock protects all of these fields.
 163    */
 164   pthread_mutex_t commands_lock;   /* lock */
 165   command_queue commands;          /* command queue */
 166   pthread_cond_t commands_cond;    /* condition (queue size 0 -> 1) */
 167   uint64_t id;                     /* next command ID */
 168 };
 169
 170 /* reexec.c */
 171 extern bool noreexec;
 172 extern char *reexeced;
 173 extern void reexec_if_needed (const char *prepend);
 174 extern int restore_ld_library_path (void);
 175
 176 /* stats.c */
 177 struct vddk_stat {
 178   const char *name;             /* function name */
 179   int64_t usecs;                /* total number of usecs consumed */
 180   uint64_t calls;               /* number of times called */
 181   uint64_t bytes;               /* bytes transferred, datapath calls only */
 182 };
 183 extern pthread_mutex_t stats_lock;
 184 #define STUB(fn, ret, args) extern struct vddk_stat stats_##fn;
 185 #define OPTIONAL_STUB(fn, ret, args) STUB (fn, ret, args)
 186 #include "vddk-stubs.h"
 187 #undef STUB
 188 #undef OPTIONAL_STUB
 189 extern void display_stats (void);
 190
 191 /* utils.c */
 192 extern void trim (char *str);
 193
 194 /* worker.c */
 195 extern const char *command_type_string (enum command_type type);
 196 extern int send_command_and_wait (struct vddk_handle *h, struct command *cmd);
 197 extern void *vddk_worker_thread (void *handle);
 198
 199 #endif /* NBDKIT_VDDK_H */