2 * Copyright (c) 2011, 2012, 2013 Spectra Logic Corporation
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30 * Authors: Justin T. Gibbs (Spectra Logic Corporation)
38 * CaseFile objects aggregate vdev faults that may require ZFSD action
39 * in order to maintain the health of a ZFS pool.
41 * Header requirements:
45 * #include "callout.h"
46 * #include "zfsd_event.h"
51 /*=========================== Forward Declarations ===========================*/
55 /*============================= Class Definitions ============================*/
56 /*------------------------------- CaseFileList -------------------------------*/
58 * CaseFileList is a specialization of the standard list STL container.
60 typedef std::list< CaseFile *> CaseFileList;
62 /*--------------------------------- CaseFile ---------------------------------*/
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
68 * A vdev may have at most one CaseFile.
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.
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
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.
89 * \brief Find a CaseFile object by a vdev's pool/vdev GUID tuple.
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.
94 * \return If found, a pointer to a valid CaseFile object.
97 static CaseFile *Find(DevdCtl::Guid poolGUID, DevdCtl::Guid vdevGUID);
100 * \brief Find a CaseFile object by a vdev's current/last known
103 * \param physPath Physical path of the vdev of the CaseFile to find.
105 * \return If found, a pointer to a valid CaseFile object.
108 static CaseFile *Find(const string &physPath);
111 * \brief ReEvaluate all open cases whose pool guid matches the argument
113 * \param poolGUID Only reevaluate cases for this pool
114 * \param event Try to consume this event with the casefile
116 static void ReEvaluateByGuid(DevdCtl::Guid poolGUID,
117 const ZfsEvent &event);
120 * \brief Create or return an existing active CaseFile for the
123 * \param vdev The vdev object for which to find/create a CaseFile.
125 * \return A reference to a valid CaseFile object.
127 static CaseFile &Create(Vdev &vdev);
130 * \brief Deserialize all serialized CaseFile objects found in
133 static void DeSerialize();
136 * \brief Emit syslog data on all active CaseFile%%s in the system.
138 static void LogAll();
141 * \brief Destroy the in-core cache of CaseFile data.
143 * This routine does not disturb the on disk, serialized, CaseFile
146 static void PurgeAll();
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;
156 * \brief Attempt to resolve this CaseFile using the disk
157 * resource at the given device/physical path/vdev object
160 * \param devPath The devfs path for the disk resource.
161 * \param physPath The physical path information reported by
163 * \param vdev If the disk contains ZFS label information,
164 * a pointer to the disk label's vdev object
165 * data. Otherwise NULL.
167 * \return True if this event was consumed by this CaseFile.
169 bool ReEvaluate(const string &devPath, const string &physPath,
173 * \brief Update this CaseFile in light of the provided ZfsEvent.
175 * Must be virtual so it can be overridden in the unit tests
177 * \param event The ZfsEvent to evaluate.
179 * \return True if this event was consumed by this CaseFile.
181 virtual bool ReEvaluate(const ZfsEvent &event);
184 * \brief Register an itimer callout for the given event, if necessary
186 virtual void RegisterCallout(const DevdCtl::Event &event);
189 * \brief Close a case if it is no longer relevant.
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.
196 * \return True if the case is closed. False otherwise.
198 bool CloseIfSolved();
201 * \brief Emit data about this CaseFile via syslog(3).
206 * \brief Whether we should degrade this vdev
208 bool ShouldDegrade() const;
211 * \brief Whether we should fault this vdev
213 bool ShouldFault() const;
218 * The number of soft errors on a vdev required
219 * to transition a vdev from healthy to degraded
222 ZFS_DEGRADE_IO_COUNT = 50
225 static CalloutFunc_t OnGracePeriodEnded;
228 * \brief scandir(3) filter function used to find files containing
229 * serialized CaseFile data.
231 * \param dirEntry Directory entry for the file to filter.
233 * \return Non-zero for a file to include in the selection,
236 static int DeSerializeSelector(const struct dirent *dirEntry);
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.
243 * \param fileName The name of a file containing serialized events
244 * from a CaseFile object.
246 static void DeSerializeFile(const char *fileName);
249 CaseFile(const Vdev &vdev);
253 * Must be virtual so it can be subclassed in the unit tests
258 * \brief Reload state for the vdev associated with this CaseFile.
260 * \return True if the refresh was successful. False if the system
261 * has no record of the pool or vdev for this CaseFile.
263 virtual bool RefreshVdevState();
266 * \brief Free all events in the m_events list.
271 * \brief Free all events in the m_tentativeEvents list.
273 void PurgeTentativeEvents();
276 * \brief Commit to file system storage.
281 * \brief Retrieve event data from a serialization stream.
283 * \param caseStream The serializtion stream to parse.
285 void DeSerialize(std::ifstream &caseStream);
288 * \brief Serializes the supplied event list and writes it to fd
290 * \param prefix If not NULL, this prefix will be prepended to
291 * every event in the file.
293 void SerializeEvList(const DevdCtl::EventList events, int fd,
294 const char* prefix=NULL) const;
297 * \brief Unconditionally close a CaseFile.
299 virtual void Close();
302 * \brief Callout callback invoked when the remove timer grace
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.
309 void OnGracePeriodEnded();
312 * \brief Attempt to activate a spare on this case's pool.
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.
319 * \return True if a spare was activated
321 bool ActivateSpare();
324 * \brief replace a pool's vdev with another
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
331 * \return true iff the replacement was successful
333 bool Replace(const char* vdev_type, const char* path, bool isspare);
336 * \brief Which vdev, if any, is replacing ours.
338 * \param zhp Pool handle state from the caller context
340 * \return the vdev that is currently replacing ours,
341 * or NonexistentVdev if there isn't one.
343 Vdev BeingReplacedBy(zpool_handle_t *zhp);
346 * \brief All CaseFiles being tracked by ZFSD.
348 static CaseFileList s_activeCases;
351 * \brief The file system path to serialized CaseFile data.
353 static const string s_caseFilePath;
356 * \brief The time ZFSD waits before promoting a tentative event
357 * into a permanent event.
359 static const timeval s_removeGracePeriod;
362 * \brief A list of soft error events counted against the health of
365 DevdCtl::EventList m_events;
368 * \brief A list of soft error events waiting for a grace period
369 * expiration before being counted against the health of
372 DevdCtl::EventList m_tentativeEvents;
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;
382 * \brief Callout activated when a grace period
384 Callout m_tentativeTimer;
387 nvlist_t *CaseVdev(zpool_handle_t *zhp) const;
391 CaseFile::PoolGUID() const
397 CaseFile::VdevGUID() const
403 CaseFile::VdevState() const
405 return (m_vdevState);
408 inline const string &
409 CaseFile::PoolGUIDString() const
411 return (m_poolGUIDString);
414 inline const string &
415 CaseFile::VdevGUIDString() const
417 return (m_vdevGUIDString);
420 inline const string &
421 CaseFile::PhysicalPath() const
423 return (m_vdevPhysPath);
426 #endif /* _CASE_FILE_H_ */