1 /*- 2 * Copyright (c) 2011, 2012, 2013 Spectra Logic Corporation 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions, and the following disclaimer, 10 * without modification. 11 * 2. Redistributions in binary form must reproduce at minimum a disclaimer 12 * substantially similar to the "NO WARRANTY" disclaimer below 13 * ("Disclaimer") and any redistribution must be conditioned upon 14 * including a substantially similar Disclaimer requirement for further 15 * binary redistribution. 16 * 17 * NO WARRANTY 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR 21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 22 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 26 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 27 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 28 * POSSIBILITY OF SUCH DAMAGES. 29 * 30 * Authors: Justin T. Gibbs (Spectra Logic Corporation) 31 * 32 * $FreeBSD$ 33 */ 34 35 /** 36 * \file case_file.h 37 * 38 * CaseFile objects aggregate vdev faults that may require ZFSD action 39 * in order to maintain the health of a ZFS pool. 40 * 41 * Header requirements: 42 * 43 * #include <list> 44 * 45 * #include "callout.h" 46 * #include "zfsd_event.h" 47 */ 48 #ifndef _CASE_FILE_H_ 49 #define _CASE_FILE_H_ 50 51 /*=========================== Forward Declarations ===========================*/ 52 class CaseFile; 53 class Vdev; 54 55 /*============================= Class Definitions ============================*/ 56 /*------------------------------- CaseFileList -------------------------------*/ 57 /** 58 * CaseFileList is a specialization of the standard list STL container. 59 */ 60 typedef std::list< CaseFile *> CaseFileList; 61 62 /*--------------------------------- CaseFile ---------------------------------*/ 63 /** 64 * A CaseFile object is instantiated anytime a vdev for an active pool 65 * experiences an I/O error, is faulted by ZFS, or is determined to be 66 * missing/removed. 67 * 68 * A vdev may have at most one CaseFile. 69 * 70 * CaseFiles are retired when a vdev leaves an active pool configuration 71 * or an action is taken to resolve the issues recorded in the CaseFile. 72 * 73 * Logging a case against a vdev does not imply that an immediate action 74 * to resolve a fault is required or even desired. For example, a CaseFile 75 * must accumulate a number of I/O errors in order to flag a device as 76 * degraded. 77 * 78 * Vdev I/O errors are not recorded in ZFS label inforamation. For this 79 * reasons, CaseFile%%s with accumulated I/O error events are serialized 80 * to the file system so that they survive across boots. Currently all 81 * other fault types can be reconstructed from ZFS label information, so 82 * CaseFile%%s for missing, faulted, or degradded members are just recreated 83 * at ZFSD startup instead of being deserialized from the file system. 84 */ 85 class CaseFile 86 { 87 public: 88 /** 89 * \brief Find a CaseFile object by a vdev's pool/vdev GUID tuple. 90 * 91 * \param poolGUID Pool GUID for the vdev of the CaseFile to find. 92 * If InvalidGuid, then only match the vdev GUID 93 * instead of both pool and vdev GUIDs. 94 * \param vdevGUID Vdev GUID for the vdev of the CaseFile to find. 95 * 96 * \return If found, a pointer to a valid CaseFile object. 97 * Otherwise NULL. 98 */ 99 static CaseFile *Find(DevdCtl::Guid poolGUID, DevdCtl::Guid vdevGUID); 100 101 /** 102 * \brief Find a CaseFile object by a vdev's current/last known 103 * physical path. 104 * 105 * \param physPath Physical path of the vdev of the CaseFile to find. 106 * 107 * \return If found, a pointer to a valid CaseFile object. 108 * Otherwise NULL. 109 */ 110 static CaseFile *Find(const string &physPath); 111 112 /** 113 * \brief ReEvaluate all open cases whose pool guid matches the argument 114 * 115 * \param poolGUID Only reevaluate cases for this pool 116 * \param event Try to consume this event with the casefile 117 */ 118 static void ReEvaluateByGuid(DevdCtl::Guid poolGUID, 119 const ZfsEvent &event); 120 121 /** 122 * \brief Create or return an existing active CaseFile for the 123 * specified vdev. 124 * 125 * \param vdev The vdev object for which to find/create a CaseFile. 126 * 127 * \return A reference to a valid CaseFile object. 128 */ 129 static CaseFile &Create(Vdev &vdev); 130 131 /** 132 * \brief Deserialize all serialized CaseFile objects found in 133 * the file system. 134 */ 135 static void DeSerialize(); 136 137 /** 138 * \brief returns true if there are no CaseFiles 139 */ 140 static bool Empty(); 141 142 /** 143 * \brief Emit syslog data on all active CaseFile%%s in the system. 144 */ 145 static void LogAll(); 146 147 /** 148 * \brief Destroy the in-core cache of CaseFile data. 149 * 150 * This routine does not disturb the on disk, serialized, CaseFile 151 * data. 152 */ 153 static void PurgeAll(); 154 155 DevdCtl::Guid PoolGUID() const; 156 DevdCtl::Guid VdevGUID() const; 157 vdev_state VdevState() const; 158 const string &PoolGUIDString() const; 159 const string &VdevGUIDString() const; 160 const string &PhysicalPath() const; 161 162 /** 163 * \brief Attempt to resolve this CaseFile using the disk 164 * resource at the given device/physical path/vdev object 165 * tuple. 166 * 167 * \param devPath The devfs path for the disk resource. 168 * \param physPath The physical path information reported by 169 * the disk resource. 170 * \param vdev If the disk contains ZFS label information, 171 * a pointer to the disk label's vdev object 172 * data. Otherwise NULL. 173 * 174 * \return True if this event was consumed by this CaseFile. 175 */ 176 bool ReEvaluate(const string &devPath, const string &physPath, 177 Vdev *vdev); 178 179 /** 180 * \brief Update this CaseFile in light of the provided ZfsEvent. 181 * 182 * Must be virtual so it can be overridden in the unit tests 183 * 184 * \param event The ZfsEvent to evaluate. 185 * 186 * \return True if this event was consumed by this CaseFile. 187 */ 188 virtual bool ReEvaluate(const ZfsEvent &event); 189 190 /** 191 * \brief Register an itimer callout for the given event, if necessary 192 */ 193 virtual void RegisterCallout(const DevdCtl::Event &event); 194 195 /** 196 * \brief Close a case if it is no longer relevant. 197 * 198 * This method deals with cases tracking soft errors. Soft errors 199 * will be discarded should a remove event occur within a short period 200 * of the soft errors being reported. We also discard the events 201 * if the vdev is marked degraded or failed. 202 * 203 * \return True if the case is closed. False otherwise. 204 */ 205 bool CloseIfSolved(); 206 207 /** 208 * \brief Emit data about this CaseFile via syslog(3). 209 */ 210 void Log(); 211 212 /** 213 * \brief Whether we should degrade this vdev 214 */ 215 bool ShouldDegrade() const; 216 217 /** 218 * \brief Whether we should fault this vdev 219 */ 220 bool ShouldFault() const; 221 222 protected: 223 enum { 224 /** 225 * The number of soft errors on a vdev required 226 * to transition a vdev from healthy to degraded 227 * status. 228 */ 229 ZFS_DEGRADE_IO_COUNT = 50 230 }; 231 232 static CalloutFunc_t OnGracePeriodEnded; 233 234 /** 235 * \brief scandir(3) filter function used to find files containing 236 * serialized CaseFile data. 237 * 238 * \param dirEntry Directory entry for the file to filter. 239 * 240 * \return Non-zero for a file to include in the selection, 241 * otherwise 0. 242 */ 243 static int DeSerializeSelector(const struct dirent *dirEntry); 244 245 /** 246 * \brief Given the name of a file containing serialized events from a 247 * CaseFile object, create/update an in-core CaseFile object 248 * representing the serialized data. 249 * 250 * \param fileName The name of a file containing serialized events 251 * from a CaseFile object. 252 */ 253 static void DeSerializeFile(const char *fileName); 254 255 /** Constructor. */ 256 CaseFile(const Vdev &vdev); 257 258 /** 259 * Destructor. 260 * Must be virtual so it can be subclassed in the unit tests 261 */ 262 virtual ~CaseFile(); 263 264 /** 265 * \brief Reload state for the vdev associated with this CaseFile. 266 * 267 * \return True if the refresh was successful. False if the system 268 * has no record of the pool or vdev for this CaseFile. 269 */ 270 virtual bool RefreshVdevState(); 271 272 /** 273 * \brief Free all events in the m_events list. 274 */ 275 void PurgeEvents(); 276 277 /** 278 * \brief Free all events in the m_tentativeEvents list. 279 */ 280 void PurgeTentativeEvents(); 281 282 /** 283 * \brief Commit to file system storage. 284 */ 285 void Serialize(); 286 287 /** 288 * \brief Retrieve event data from a serialization stream. 289 * 290 * \param caseStream The serializtion stream to parse. 291 */ 292 void DeSerialize(std::ifstream &caseStream); 293 294 /** 295 * \brief Serializes the supplied event list and writes it to fd 296 * 297 * \param prefix If not NULL, this prefix will be prepended to 298 * every event in the file. 299 */ 300 void SerializeEvList(const DevdCtl::EventList events, int fd, 301 const char* prefix=NULL) const; 302 303 /** 304 * \brief Unconditionally close a CaseFile. 305 */ 306 virtual void Close(); 307 308 /** 309 * \brief Callout callback invoked when the remove timer grace 310 * period expires. 311 * 312 * If no remove events are received prior to the grace period 313 * firing, then any tentative events are promoted and counted 314 * against the health of the vdev. 315 */ 316 void OnGracePeriodEnded(); 317 318 /** 319 * \brief Attempt to activate a spare on this case's pool. 320 * 321 * Call this whenever a pool becomes degraded. It will look for any 322 * spare devices and activate one to replace the casefile's vdev. It 323 * will _not_ close the casefile; that should only happen when the 324 * missing drive is replaced or the user promotes the spare. 325 * 326 * \return True if a spare was activated 327 */ 328 bool ActivateSpare(); 329 330 /** 331 * \brief replace a pool's vdev with another 332 * 333 * \param vdev_type The type of the new vdev. Usually either 334 * VDEV_TYPE_DISK or VDEV_TYPE_FILE 335 * \param path The file system path to the new vdev 336 * \param isspare Whether the new vdev is a spare 337 * 338 * \return true iff the replacement was successful 339 */ 340 bool Replace(const char* vdev_type, const char* path, bool isspare); 341 342 /** 343 * \brief Which vdev, if any, is replacing ours. 344 * 345 * \param zhp Pool handle state from the caller context 346 * 347 * \return the vdev that is currently replacing ours, 348 * or NonexistentVdev if there isn't one. 349 */ 350 Vdev BeingReplacedBy(zpool_handle_t *zhp); 351 352 /** 353 * \brief All CaseFiles being tracked by ZFSD. 354 */ 355 static CaseFileList s_activeCases; 356 357 /** 358 * \brief The file system path to serialized CaseFile data. 359 */ 360 static const string s_caseFilePath; 361 362 /** 363 * \brief The time ZFSD waits before promoting a tentative event 364 * into a permanent event. 365 */ 366 static const timeval s_removeGracePeriod; 367 368 /** 369 * \brief A list of soft error events counted against the health of 370 * a vdev. 371 */ 372 DevdCtl::EventList m_events; 373 374 /** 375 * \brief A list of soft error events waiting for a grace period 376 * expiration before being counted against the health of 377 * a vdev. 378 */ 379 DevdCtl::EventList m_tentativeEvents; 380 381 DevdCtl::Guid m_poolGUID; 382 DevdCtl::Guid m_vdevGUID; 383 vdev_state m_vdevState; 384 string m_poolGUIDString; 385 string m_vdevGUIDString; 386 string m_vdevPhysPath; 387 388 /** 389 * \brief Callout activated when a grace period 390 */ 391 Callout m_tentativeTimer; 392 393 private: 394 nvlist_t *CaseVdev(zpool_handle_t *zhp) const; 395 }; 396 397 inline DevdCtl::Guid 398 CaseFile::PoolGUID() const 399 { 400 return (m_poolGUID); 401 } 402 403 inline DevdCtl::Guid 404 CaseFile::VdevGUID() const 405 { 406 return (m_vdevGUID); 407 } 408 409 inline vdev_state 410 CaseFile::VdevState() const 411 { 412 return (m_vdevState); 413 } 414 415 inline const string & 416 CaseFile::PoolGUIDString() const 417 { 418 return (m_poolGUIDString); 419 } 420 421 inline const string & 422 CaseFile::VdevGUIDString() const 423 { 424 return (m_vdevGUIDString); 425 } 426 427 inline const string & 428 CaseFile::PhysicalPath() const 429 { 430 return (m_vdevPhysPath); 431 } 432 433 #endif /* _CASE_FILE_H_ */ 434