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 Emit syslog data on all active CaseFile%%s in the system. 139 */ 140 static void LogAll(); 141 142 /** 143 * \brief Destroy the in-core cache of CaseFile data. 144 * 145 * This routine does not disturb the on disk, serialized, CaseFile 146 * data. 147 */ 148 static void PurgeAll(); 149 150 DevdCtl::Guid PoolGUID() const; 151 DevdCtl::Guid VdevGUID() const; 152 vdev_state VdevState() const; 153 const string &PoolGUIDString() const; 154 const string &VdevGUIDString() const; 155 const string &PhysicalPath() const; 156 157 /** 158 * \brief Attempt to resolve this CaseFile using the disk 159 * resource at the given device/physical path/vdev object 160 * tuple. 161 * 162 * \param devPath The devfs path for the disk resource. 163 * \param physPath The physical path information reported by 164 * the disk resource. 165 * \param vdev If the disk contains ZFS label information, 166 * a pointer to the disk label's vdev object 167 * data. Otherwise NULL. 168 * 169 * \return True if this event was consumed by this CaseFile. 170 */ 171 bool ReEvaluate(const string &devPath, const string &physPath, 172 Vdev *vdev); 173 174 /** 175 * \brief Update this CaseFile in light of the provided ZfsEvent. 176 * 177 * Must be virtual so it can be overridden in the unit tests 178 * 179 * \param event The ZfsEvent to evaluate. 180 * 181 * \return True if this event was consumed by this CaseFile. 182 */ 183 virtual bool ReEvaluate(const ZfsEvent &event); 184 185 /** 186 * \brief Register an itimer callout for the given event, if necessary 187 */ 188 virtual void RegisterCallout(const DevdCtl::Event &event); 189 190 /** 191 * \brief Close a case if it is no longer relevant. 192 * 193 * This method deals with cases tracking soft errors. Soft errors 194 * will be discarded should a remove event occur within a short period 195 * of the soft errors being reported. We also discard the events 196 * if the vdev is marked degraded or failed. 197 * 198 * \return True if the case is closed. False otherwise. 199 */ 200 bool CloseIfSolved(); 201 202 /** 203 * \brief Emit data about this CaseFile via syslog(3). 204 */ 205 void Log(); 206 207 /** 208 * \brief Whether we should degrade this vdev 209 */ 210 bool ShouldDegrade() const; 211 212 /** 213 * \brief Whether we should fault this vdev 214 */ 215 bool ShouldFault() const; 216 217 protected: 218 enum { 219 /** 220 * The number of soft errors on a vdev required 221 * to transition a vdev from healthy to degraded 222 * status. 223 */ 224 ZFS_DEGRADE_IO_COUNT = 50 225 }; 226 227 static CalloutFunc_t OnGracePeriodEnded; 228 229 /** 230 * \brief scandir(3) filter function used to find files containing 231 * serialized CaseFile data. 232 * 233 * \param dirEntry Directory entry for the file to filter. 234 * 235 * \return Non-zero for a file to include in the selection, 236 * otherwise 0. 237 */ 238 static int DeSerializeSelector(const struct dirent *dirEntry); 239 240 /** 241 * \brief Given the name of a file containing serialized events from a 242 * CaseFile object, create/update an in-core CaseFile object 243 * representing the serialized data. 244 * 245 * \param fileName The name of a file containing serialized events 246 * from a CaseFile object. 247 */ 248 static void DeSerializeFile(const char *fileName); 249 250 /** Constructor. */ 251 CaseFile(const Vdev &vdev); 252 253 /** 254 * Destructor. 255 * Must be virtual so it can be subclassed in the unit tests 256 */ 257 virtual ~CaseFile(); 258 259 /** 260 * \brief Reload state for the vdev associated with this CaseFile. 261 * 262 * \return True if the refresh was successful. False if the system 263 * has no record of the pool or vdev for this CaseFile. 264 */ 265 virtual bool RefreshVdevState(); 266 267 /** 268 * \brief Free all events in the m_events list. 269 */ 270 void PurgeEvents(); 271 272 /** 273 * \brief Free all events in the m_tentativeEvents list. 274 */ 275 void PurgeTentativeEvents(); 276 277 /** 278 * \brief Commit to file system storage. 279 */ 280 void Serialize(); 281 282 /** 283 * \brief Retrieve event data from a serialization stream. 284 * 285 * \param caseStream The serializtion stream to parse. 286 */ 287 void DeSerialize(std::ifstream &caseStream); 288 289 /** 290 * \brief Serializes the supplied event list and writes it to fd 291 * 292 * \param prefix If not NULL, this prefix will be prepended to 293 * every event in the file. 294 */ 295 void SerializeEvList(const DevdCtl::EventList events, int fd, 296 const char* prefix=NULL) const; 297 298 /** 299 * \brief Unconditionally close a CaseFile. 300 */ 301 virtual void Close(); 302 303 /** 304 * \brief Callout callback invoked when the remove timer grace 305 * period expires. 306 * 307 * If no remove events are received prior to the grace period 308 * firing, then any tentative events are promoted and counted 309 * against the health of the vdev. 310 */ 311 void OnGracePeriodEnded(); 312 313 /** 314 * \brief Attempt to activate a spare on this case's pool. 315 * 316 * Call this whenever a pool becomes degraded. It will look for any 317 * spare devices and activate one to replace the casefile's vdev. It 318 * will _not_ close the casefile; that should only happen when the 319 * missing drive is replaced or the user promotes the spare. 320 * 321 * \return True if a spare was activated 322 */ 323 bool ActivateSpare(); 324 325 /** 326 * \brief replace a pool's vdev with another 327 * 328 * \param vdev_type The type of the new vdev. Usually either 329 * VDEV_TYPE_DISK or VDEV_TYPE_FILE 330 * \param path The file system path to the new vdev 331 * \param isspare Whether the new vdev is a spare 332 * 333 * \return true iff the replacement was successful 334 */ 335 bool Replace(const char* vdev_type, const char* path, bool isspare); 336 337 /** 338 * \brief Which vdev, if any, is replacing ours. 339 * 340 * \param zhp Pool handle state from the caller context 341 * 342 * \return the vdev that is currently replacing ours, 343 * or NonexistentVdev if there isn't one. 344 */ 345 Vdev BeingReplacedBy(zpool_handle_t *zhp); 346 347 /** 348 * \brief All CaseFiles being tracked by ZFSD. 349 */ 350 static CaseFileList s_activeCases; 351 352 /** 353 * \brief The file system path to serialized CaseFile data. 354 */ 355 static const string s_caseFilePath; 356 357 /** 358 * \brief The time ZFSD waits before promoting a tentative event 359 * into a permanent event. 360 */ 361 static const timeval s_removeGracePeriod; 362 363 /** 364 * \brief A list of soft error events counted against the health of 365 * a vdev. 366 */ 367 DevdCtl::EventList m_events; 368 369 /** 370 * \brief A list of soft error events waiting for a grace period 371 * expiration before being counted against the health of 372 * a vdev. 373 */ 374 DevdCtl::EventList m_tentativeEvents; 375 376 DevdCtl::Guid m_poolGUID; 377 DevdCtl::Guid m_vdevGUID; 378 vdev_state m_vdevState; 379 string m_poolGUIDString; 380 string m_vdevGUIDString; 381 string m_vdevPhysPath; 382 383 /** 384 * \brief Callout activated when a grace period 385 */ 386 Callout m_tentativeTimer; 387 388 private: 389 nvlist_t *CaseVdev(zpool_handle_t *zhp) const; 390 }; 391 392 inline DevdCtl::Guid 393 CaseFile::PoolGUID() const 394 { 395 return (m_poolGUID); 396 } 397 398 inline DevdCtl::Guid 399 CaseFile::VdevGUID() const 400 { 401 return (m_vdevGUID); 402 } 403 404 inline vdev_state 405 CaseFile::VdevState() const 406 { 407 return (m_vdevState); 408 } 409 410 inline const string & 411 CaseFile::PoolGUIDString() const 412 { 413 return (m_poolGUIDString); 414 } 415 416 inline const string & 417 CaseFile::VdevGUIDString() const 418 { 419 return (m_vdevGUIDString); 420 } 421 422 inline const string & 423 CaseFile::PhysicalPath() const 424 { 425 return (m_vdevPhysPath); 426 } 427 428 #endif /* _CASE_FILE_H_ */ 429