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 * \param vdevGUID Vdev GUID for the vdev of the CaseFile to find. 93 * 94 * \return If found, a pointer to a valid CaseFile object. 95 * Otherwise NULL. 96 */ 97 static CaseFile *Find(DevdCtl::Guid poolGUID, DevdCtl::Guid vdevGUID); 98 99 /** 100 * \brief Find a CaseFile object by a vdev's current/last known 101 * physical path. 102 * 103 * \param physPath Physical path of the vdev of the CaseFile to find. 104 * 105 * \return If found, a pointer to a valid CaseFile object. 106 * Otherwise NULL. 107 */ 108 static CaseFile *Find(const string &physPath); 109 110 /** 111 * \brief ReEvaluate all open cases whose pool guid matches the argument 112 * 113 * \param poolGUID Only reevaluate cases for this pool 114 * \param event Try to consume this event with the casefile 115 */ 116 static void ReEvaluateByGuid(DevdCtl::Guid poolGUID, 117 const ZfsEvent &event); 118 119 /** 120 * \brief Create or return an existing active CaseFile for the 121 * specified vdev. 122 * 123 * \param vdev The vdev object for which to find/create a CaseFile. 124 * 125 * \return A reference to a valid CaseFile object. 126 */ 127 static CaseFile &Create(Vdev &vdev); 128 129 /** 130 * \brief Deserialize all serialized CaseFile objects found in 131 * the file system. 132 */ 133 static void DeSerialize(); 134 135 /** 136 * \brief Emit syslog data on all active CaseFile%%s in the system. 137 */ 138 static void LogAll(); 139 140 /** 141 * \brief Destroy the in-core cache of CaseFile data. 142 * 143 * This routine does not disturb the on disk, serialized, CaseFile 144 * data. 145 */ 146 static void PurgeAll(); 147 148 DevdCtl::Guid PoolGUID() const; 149 DevdCtl::Guid VdevGUID() const; 150 vdev_state VdevState() const; 151 const string &PoolGUIDString() const; 152 const string &VdevGUIDString() const; 153 const string &PhysicalPath() const; 154 155 /** 156 * \brief Attempt to resolve this CaseFile using the disk 157 * resource at the given device/physical path/vdev object 158 * tuple. 159 * 160 * \param devPath The devfs path for the disk resource. 161 * \param physPath The physical path information reported by 162 * the disk resource. 163 * \param vdev If the disk contains ZFS label information, 164 * a pointer to the disk label's vdev object 165 * data. Otherwise NULL. 166 * 167 * \return True if this event was consumed by this CaseFile. 168 */ 169 bool ReEvaluate(const string &devPath, const string &physPath, 170 Vdev *vdev); 171 172 /** 173 * \brief Update this CaseFile in light of the provided ZfsEvent. 174 * 175 * Must be virtual so it can be overridden in the unit tests 176 * 177 * \param event The ZfsEvent to evaluate. 178 * 179 * \return True if this event was consumed by this CaseFile. 180 */ 181 virtual bool ReEvaluate(const ZfsEvent &event); 182 183 /** 184 * \brief Register an itimer callout for the given event, if necessary 185 */ 186 virtual void RegisterCallout(const DevdCtl::Event &event); 187 188 /** 189 * \brief Close a case if it is no longer relevant. 190 * 191 * This method deals with cases tracking soft errors. Soft errors 192 * will be discarded should a remove event occur within a short period 193 * of the soft errors being reported. We also discard the events 194 * if the vdev is marked degraded or failed. 195 * 196 * \return True if the case is closed. False otherwise. 197 */ 198 bool CloseIfSolved(); 199 200 /** 201 * \brief Emit data about this CaseFile via syslog(3). 202 */ 203 void Log(); 204 205 /** 206 * \brief Whether we should degrade this vdev 207 */ 208 bool ShouldDegrade() const; 209 210 /** 211 * \brief Whether we should fault this vdev 212 */ 213 bool ShouldFault() const; 214 215 protected: 216 enum { 217 /** 218 * The number of soft errors on a vdev required 219 * to transition a vdev from healthy to degraded 220 * status. 221 */ 222 ZFS_DEGRADE_IO_COUNT = 50 223 }; 224 225 static CalloutFunc_t OnGracePeriodEnded; 226 227 /** 228 * \brief scandir(3) filter function used to find files containing 229 * serialized CaseFile data. 230 * 231 * \param dirEntry Directory entry for the file to filter. 232 * 233 * \return Non-zero for a file to include in the selection, 234 * otherwise 0. 235 */ 236 static int DeSerializeSelector(const struct dirent *dirEntry); 237 238 /** 239 * \brief Given the name of a file containing serialized events from a 240 * CaseFile object, create/update an in-core CaseFile object 241 * representing the serialized data. 242 * 243 * \param fileName The name of a file containing serialized events 244 * from a CaseFile object. 245 */ 246 static void DeSerializeFile(const char *fileName); 247 248 /** Constructor. */ 249 CaseFile(const Vdev &vdev); 250 251 /** 252 * Destructor. 253 * Must be virtual so it can be subclassed in the unit tests 254 */ 255 virtual ~CaseFile(); 256 257 /** 258 * \brief Reload state for the vdev associated with this CaseFile. 259 * 260 * \return True if the refresh was successful. False if the system 261 * has no record of the pool or vdev for this CaseFile. 262 */ 263 virtual bool RefreshVdevState(); 264 265 /** 266 * \brief Free all events in the m_events list. 267 */ 268 void PurgeEvents(); 269 270 /** 271 * \brief Free all events in the m_tentativeEvents list. 272 */ 273 void PurgeTentativeEvents(); 274 275 /** 276 * \brief Commit to file system storage. 277 */ 278 void Serialize(); 279 280 /** 281 * \brief Retrieve event data from a serialization stream. 282 * 283 * \param caseStream The serializtion stream to parse. 284 */ 285 void DeSerialize(std::ifstream &caseStream); 286 287 /** 288 * \brief Serializes the supplied event list and writes it to fd 289 * 290 * \param prefix If not NULL, this prefix will be prepended to 291 * every event in the file. 292 */ 293 void SerializeEvList(const DevdCtl::EventList events, int fd, 294 const char* prefix=NULL) const; 295 296 /** 297 * \brief Unconditionally close a CaseFile. 298 */ 299 virtual void Close(); 300 301 /** 302 * \brief Callout callback invoked when the remove timer grace 303 * period expires. 304 * 305 * If no remove events are received prior to the grace period 306 * firing, then any tentative events are promoted and counted 307 * against the health of the vdev. 308 */ 309 void OnGracePeriodEnded(); 310 311 /** 312 * \brief Attempt to activate a spare on this case's pool. 313 * 314 * Call this whenever a pool becomes degraded. It will look for any 315 * spare devices and activate one to replace the casefile's vdev. It 316 * will _not_ close the casefile; that should only happen when the 317 * missing drive is replaced or the user promotes the spare. 318 * 319 * \return True if a spare was activated 320 */ 321 bool ActivateSpare(); 322 323 /** 324 * \brief replace a pool's vdev with another 325 * 326 * \param vdev_type The type of the new vdev. Usually either 327 * VDEV_TYPE_DISK or VDEV_TYPE_FILE 328 * \param path The file system path to the new vdev 329 * \param isspare Whether the new vdev is a spare 330 * 331 * \return true iff the replacement was successful 332 */ 333 bool Replace(const char* vdev_type, const char* path, bool isspare); 334 335 /** 336 * \brief Which vdev, if any, is replacing ours. 337 * 338 * \param zhp Pool handle state from the caller context 339 * 340 * \return the vdev that is currently replacing ours, 341 * or NonexistentVdev if there isn't one. 342 */ 343 Vdev BeingReplacedBy(zpool_handle_t *zhp); 344 345 /** 346 * \brief All CaseFiles being tracked by ZFSD. 347 */ 348 static CaseFileList s_activeCases; 349 350 /** 351 * \brief The file system path to serialized CaseFile data. 352 */ 353 static const string s_caseFilePath; 354 355 /** 356 * \brief The time ZFSD waits before promoting a tentative event 357 * into a permanent event. 358 */ 359 static const timeval s_removeGracePeriod; 360 361 /** 362 * \brief A list of soft error events counted against the health of 363 * a vdev. 364 */ 365 DevdCtl::EventList m_events; 366 367 /** 368 * \brief A list of soft error events waiting for a grace period 369 * expiration before being counted against the health of 370 * a vdev. 371 */ 372 DevdCtl::EventList m_tentativeEvents; 373 374 DevdCtl::Guid m_poolGUID; 375 DevdCtl::Guid m_vdevGUID; 376 vdev_state m_vdevState; 377 string m_poolGUIDString; 378 string m_vdevGUIDString; 379 string m_vdevPhysPath; 380 381 /** 382 * \brief Callout activated when a grace period 383 */ 384 Callout m_tentativeTimer; 385 386 private: 387 nvlist_t *CaseVdev(zpool_handle_t *zhp) const; 388 }; 389 390 inline DevdCtl::Guid 391 CaseFile::PoolGUID() const 392 { 393 return (m_poolGUID); 394 } 395 396 inline DevdCtl::Guid 397 CaseFile::VdevGUID() const 398 { 399 return (m_vdevGUID); 400 } 401 402 inline vdev_state 403 CaseFile::VdevState() const 404 { 405 return (m_vdevState); 406 } 407 408 inline const string & 409 CaseFile::PoolGUIDString() const 410 { 411 return (m_poolGUIDString); 412 } 413 414 inline const string & 415 CaseFile::VdevGUIDString() const 416 { 417 return (m_vdevGUIDString); 418 } 419 420 inline const string & 421 CaseFile::PhysicalPath() const 422 { 423 return (m_vdevPhysPath); 424 } 425 426 #endif /* _CASE_FILE_H_ */ 427