include/sys/flock.h

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*      Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
  23 /*        All Rights Reserved   */
  24
  25
  26 /*
  27  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
  28  * Use is subject to license terms.
  29  */
  30 /*
  31  * Copyright 2013 Nexenta Systems, Inc.  All rights reserved.
  32  * Copyright 2015 Joyent, Inc.
  33  */
  34
  35 #ifndef _SYS_FLOCK_H
  36 #define _SYS_FLOCK_H
  37
  38 #include <sys/types.h>
  39 #include <sys/fcntl.h>
  40 #include <sys/vnode.h>
  41 #include <sys/t_lock.h>         /* for <sys/callb.h> */
  42 #include <sys/callb.h>
  43 #include <sys/param.h>
  44 #include <sys/zone.h>
  45 #if defined(_KERNEL)
  46 #include <sys/file.h>
  47 #endif
  48
  49 #ifdef  __cplusplus
  50 extern "C" {
  51 #endif
  52
  53 /*
  54  * Private declarations and instrumentation for local locking.
  55  */
  56
  57 /*
  58  * The command passed to reclock() is made by ORing together one or more of
  59  * the following values.
  60  */
  61
  62 #define INOFLCK         0x01    /* Vnode is locked when reclock() is called. */
  63 #define SETFLCK         0x02    /* Set a file lock. */
  64 #define SLPFLCK         0x04    /* Wait if blocked. */
  65 #define RCMDLCK         0x08    /* F_REMOTELOCK specified */
  66 #define NBMLCK          0x20    /* non-blocking mandatory locking */
  67
  68 /*
  69  * Special pid value that can be passed to cleanlocks().  It means that
  70  * cleanlocks() should flush all locks for the given sysid, not just the
  71  * locks owned by a specific process.
  72  */
  73
  74 #define IGN_PID         (-1)
  75
  76 /* file locking structure (connected to vnode) */
  77
  78 #define l_end           l_len
  79
  80 /*
  81  * The lock manager is allowed to use unsigned offsets and lengths, though
  82  * regular Unix processes are still required to use signed offsets and
  83  * lengths.
  84  */
  85 typedef ulong_t u_off_t;
  86
  87 #define MAX_U_OFF_T     ((u_off_t)~0)
  88 #define MAX_U_OFFSET_T  ((uoff_t)~0)
  89
  90 /*
  91  * define MAXEND as the largest positive value the signed offset_t will hold.
  92  */
  93 #define MAXEND          MAXOFFSET_T
  94
  95 /*
  96  * Definitions for accessing the l_pad area of struct flock.  The
  97  * descriminant of the pad_info_t union is the fcntl command used in
  98  * conjunction with the flock struct.
  99  */
 100
 101 typedef union {
 102         int     pi_pad[4];              /* (original pad area) */
 103         int     pi_has_rmt;             /* F_HASREMOTELOCKS */
 104 } pad_info_t;
 105
 106 #define l_has_rmt(flockp)       (((pad_info_t *)((flockp)->l_pad))->pi_has_rmt)
 107
 108 /*
 109  * Optional callbacks for blocking lock requests.  Each function is called
 110  * twice.
 111  * The first call is after the request is put in the "sleeping" list, but
 112  *   before waiting.  At most one callback may return a callb_cpr_t object;
 113  *   the others must return NULL.  If a callb_cpr_t is returned, the thread
 114  *   will be marked as safe to suspend while waiting for the lock.
 115  * The second call is after the request wakes up.  Note that the request
 116  *   might not have been granted at the second call (e.g., the request was
 117  *   signalled).
 118  * New callbacks should be added to the head of the list.  For the first
 119  * call the list is walked in order.  For the second call the list is
 120  * walked backwards (in case the callbacks need to reacquire locks).
 121  */
 122
 123 typedef enum {FLK_BEFORE_SLEEP, FLK_AFTER_SLEEP} flk_cb_when_t;
 124
 125 struct flk_callback {
 126         struct flk_callback *cb_next;   /* circular linked list */
 127         struct flk_callback *cb_prev;
 128         callb_cpr_t     *(*cb_callback)(flk_cb_when_t, void *); /* fcn ptr */
 129         void            *cb_data;       /* ptr to callback data */
 130 };
 131
 132 typedef struct flk_callback flk_callback_t;
 133
 134 /*
 135  * This structure members are not used any more inside the kernel.
 136  * The structure is used for casting some pointer assignments only.
 137  */
 138
 139 typedef struct filock {
 140         kcondvar_t cv;
 141         struct  flock set;      /* contains type, start, and end */
 142         struct  {
 143                 int granted_flag;       /* granted flag */
 144                 struct filock *blk;     /* for sleeping locks only */
 145                 struct attacher *blocking_list;
 146                 struct attacher *my_attacher;
 147         }       stat;
 148         struct  filock *prev;
 149         struct  filock *next;
 150 } filock_t;
 151
 152 #define FLP_DELAYED_FREE        -1      /* special value for granted_flag */
 153
 154 /* structure that contains list of locks to be granted */
 155
 156 #define MAX_GRANT_LOCKS         52
 157
 158 typedef struct grant_lock {
 159         struct filock *grant_lock_list[MAX_GRANT_LOCKS];
 160         struct grant_lock *next;
 161 } grant_lock_t;
 162
 163 /*
 164  * Provide a way to cleanly enable and disable Network Lock Manager locking
 165  * requests (i.e., requests from remote clients):
 166  *    FLK_NLM_SHUTTING_DOWN: Forces all blocked NLM requests to bail out
 167  *      and return ENOLCK.
 168  *    FLK_NLM_DOWN: Clears all granted NLM server locks.  Both status
 169  *      codes cause new NLM lock requests to fail immediately with ENOLCK.
 170  *    FLK_NLM_UP: Changes the state of all locks to UP, after a server has
 171  *      shutdown and is restarting on the same node.
 172  */
 173
 174 /*
 175  * Enumerated type of the four possible states an NLM server can be in.
 176  */
 177 typedef enum {
 178         FLK_NLM_UP,
 179         FLK_NLM_SHUTTING_DOWN,
 180         FLK_NLM_DOWN,
 181         FLK_NLM_UNKNOWN
 182 } flk_nlm_status_t;
 183
 184 /*
 185  * Provide a way to cleanly enable and disable lock manager locking
 186  * requests (i.e., requests from remote clients).  FLK_WAKEUP_SLEEPERS
 187  * forces all blocked lock manager requests to bail out and return ENOLCK.
 188  * FLK_LOCKMGR_DOWN clears all granted lock manager locks.  Both status
 189  * codes cause new lock manager requests to fail immediately with ENOLCK.
 190  */
 191
 192 typedef enum {
 193     FLK_LOCKMGR_UP,
 194     FLK_WAKEUP_SLEEPERS,
 195     FLK_LOCKMGR_DOWN
 196 } flk_lockmgr_status_t;
 197
 198 #if defined(_KERNEL)
 199
 200 /*
 201  * The following structure is used to hold a list of locks returned
 202  * by the F_ACTIVELIST or F_SLEEPINGLIST commands to fs_frlock.
 203  *
 204  * N.B. The lists returned by these commands are dynamically
 205  * allocated and must be freed by the caller.  The vnodes returned
 206  * in the lists are held and must be released when the caller is done.
 207  */
 208
 209 typedef struct locklist {
 210         struct vnode *ll_vp;
 211         struct flock64 ll_flock;
 212         struct locklist *ll_next;
 213 } locklist_t;
 214
 215 #define FLK_QUERY_ACTIVE        0x1
 216 #define FLK_QUERY_SLEEPING      0x2
 217
 218 #if defined(_KERNEL)
 219 int     ofdlock(file_t *, int, struct flock64 *, int, uoff_t);
 220 void    ofdcleanlock(file_t *);
 221 #endif
 222 int     reclock(struct vnode *, struct flock64 *, int, int, uoff_t,
 223                 flk_callback_t *);
 224 int     chklock(struct vnode *, int, uoff_t, ssize_t, int,
 225                 caller_context_t *);
 226 int     convoff(struct vnode *, struct flock64 *, int, offset_t);
 227 void    cleanlocks(struct vnode *, pid_t, int);
 228 locklist_t *flk_get_sleeping_locks(int sysid, pid_t pid);
 229 locklist_t *flk_get_active_locks(int sysid, pid_t pid);
 230 locklist_t *flk_active_locks_for_vp(const struct vnode *vp);
 231 locklist_t *flk_active_nbmand_locks_for_vp(const struct vnode *vp);
 232 locklist_t *flk_active_nbmand_locks(pid_t pid);
 233 void    flk_free_locklist(locklist_t *);
 234 int     flk_convert_lock_data(struct vnode *, struct flock64 *,
 235                 uoff_t *, uoff_t *, offset_t);
 236 int     flk_check_lock_data(uoff_t, uoff_t, offset_t);
 237 int     flk_has_remote_locks(struct vnode *vp);
 238 void    flk_set_lockmgr_status(flk_lockmgr_status_t status);
 239 int     flk_sysid_has_locks(int sysid, int chklck);
 240 int     flk_has_remote_locks_for_sysid(vnode_t *vp, int);
 241 void    flk_init_callback(flk_callback_t *,
 242                 callb_cpr_t *(*)(flk_cb_when_t, void *), void *);
 243 void    flk_add_callback(flk_callback_t *,
 244                 callb_cpr_t *(*)(flk_cb_when_t, void *), void *,
 245                 flk_callback_t *);
 246 void    flk_del_callback(flk_callback_t *);
 247 callb_cpr_t *flk_invoke_callbacks(flk_callback_t *, flk_cb_when_t);
 248
 249 /* Zones hooks */
 250 extern  zone_key_t flock_zone_key;
 251
 252 void    *flk_zone_init(zoneid_t);
 253 void    flk_zone_fini(zoneid_t, void *);
 254
 255 #endif /* _KERNEL */
 256
 257 #ifdef  __cplusplus
 258 }
 259 #endif
 260
 261 #endif  /* _SYS_FLOCK_H */