/* * Copyright (C) 1986-2005 The Free Software Foundation, Inc. * * Portions Copyright (C) 1998-2005 Derek Price, Ximbiot , * and others. * * Portions Copyright (C) 1992, Brian Berliner and Jeff Polk * Portions Copyright (C) 1989-1992, Brian Berliner * * You may distribute under the terms of the GNU General Public License as * specified in the README file that comes with the CVS source distribution. * * Set Lock * * Lock file support for CVS. * * $FreeBSD$ */ /* The node Concurrency in doc/cvs.texinfo has a brief introduction to how CVS locks function, and some of the user-visible consequences of their existence. Here is a summary of why they exist (and therefore, the consequences of hacking CVS to read a repository without creating locks): There are two uses. One is the ability to prevent there from being two writers at the same time. This is necessary for any number of reasons (fileattr code, probably others). Commit needs to lock the whole tree so that nothing happens between the up-to-date check and the actual checkin. The second use is the ability to ensure that there is not a writer and a reader at the same time (several readers are allowed). Reasons for this are: * Readlocks ensure that once CVS has found a collection of rcs files using Find_Names, the files will still exist when it reads them (they may have moved in or out of the attic). * Readlocks provide some modicum of consistency, although this is kind of limited--see the node Concurrency in cvs.texinfo. * Readlocks ensure that the RCS file does not change between RCS_parse and RCS_reparsercsfile time. This one strikes me as important, although I haven't thought up what bad scenarios might be. * Readlocks ensure that we won't find the file in the state in which it is in between the calls to add_rcs_file and RCS_checkin in commit.c (when a file is being added). This state is a state in which the RCS file parsing routines in rcs.c cannot parse the file. * Readlocks ensure that a reader won't try to look at a half-written fileattr file (fileattr is not updated atomically). (see also the description of anonymous read-only access in "Password authentication security" node in doc/cvs.texinfo). While I'm here, I'll try to summarize a few random suggestions which periodically get made about how locks might be different: 1. Check for EROFS. Maybe useful, although in the presence of NFS EROFS does *not* mean that the file system is unchanging. 2. Provide an option to disable locks for operations which only read (see above for some of the consequences). 3. Have a server internally do the locking. Probably a good long-term solution, and many people have been working hard on code changes which would eventually make it possible to have a server which can handle various connections in one process, but there is much, much work still to be done before this is feasible. */ #include "cvs.h" #include #ifdef HAVE_NANOSLEEP # include "xtime.h" #else /* HAVE_NANOSLEEP */ # if !defined HAVE_USLEEP && defined HAVE_SELECT /* use select as a workaround */ # include "xselect.h" # endif /* !defined HAVE_USLEEP && defined HAVE_SELECT */ #endif /* !HAVE_NANOSLEEP */ struct lock { /* This is the directory in which we may have a lock named by the readlock variable, a lock named by the writelock variable, and/or a lock named CVSLCK. The storage is not allocated along with the struct lock; it is allocated by the Reader_Lock caller or in the case of writelocks, it is just a pointer to the storage allocated for the ->key field. */ char *repository; /* The name of the master lock dir. Usually CVSLCK. */ const char *lockdirname; /* The full path to the lock dir, if we are currently holding it. * * This will be LOCKDIRNAME catted onto REPOSITORY. We waste a little * space by storing it, but save a later malloc/free. */ char *lockdir; /* Note there is no way of knowing whether the readlock and writelock exist. The code which sets the locks doesn't use SIG_beginCrSect to set a flag like we do for CVSLCK. */ }; static void remove_locks PROTO((void)); static int readers_exist PROTO((char *repository)); static int set_lock PROTO ((struct lock *lock, int will_wait)); static void clear_lock PROTO ((struct lock *lock)); static void set_lockers_name PROTO((struct stat *statp)); static int set_writelock_proc PROTO((Node * p, void *closure)); static int unlock_proc PROTO((Node * p, void *closure)); static int write_lock PROTO ((struct lock *lock)); static void lock_simple_remove PROTO ((struct lock *lock)); static void lock_wait PROTO((char *repository)); static void lock_obtained PROTO((char *repository)); /* Malloc'd array containing the username of the whoever has the lock. Will always be non-NULL in the cases where it is needed. */ static char *lockers_name; /* Malloc'd array specifying name of a readlock within a directory. Or NULL if none. */ static char *readlock; /* Malloc'd array specifying name of a writelock within a directory. Or NULL if none. */ static char *writelock; /* Malloc'd array specifying the name of a CVSLCK file (absolute pathname). Will always be non-NULL in the cases where it is used. */ static List *locklist; #define L_OK 0 /* success */ #define L_ERROR 1 /* error condition */ #define L_LOCKED 2 /* lock owned by someone else */ /* This is the (single) readlock which is set by Reader_Lock. The repository field is NULL if there is no such lock. */ static struct lock global_readlock = {NULL, CVSLCK, NULL}; static struct lock global_history_lock = {NULL, CVSHISTORYLCK, NULL}; static struct lock global_val_tags_lock = {NULL, CVSVALTAGSLCK, NULL}; /* List of locks set by lock_tree_for_write. This is redundant with locklist, sort of. */ static List *lock_tree_list; /* If we set locks with lock_dir_for_write, then locked_dir contains the malloc'd name of the repository directory which we have locked. locked_list is the same thing packaged into a list and is redundant with locklist the same way that lock_tree_list is. */ static char *locked_dir; static List *locked_list; /* LockDir from CVSROOT/config. */ char *lock_dir; static char *lock_name PROTO ((const char *repository, const char *name)); /* Return a newly malloc'd string containing the name of the lock for the repository REPOSITORY and the lock file name within that directory NAME. Also create the directories in which to put the lock file if needed (if we need to, could save system call(s) by doing that only if the actual operation fails. But for now we'll keep things simple). */ static char * lock_name (repository, name) const char *repository; const char *name; { char *retval; const char *p; char *q; const char *short_repos; mode_t save_umask = 0; int saved_umask = 0; if (lock_dir == NULL) { /* This is the easy case. Because the lock files go directly in the repository, no need to create directories or anything. */ retval = xmalloc (strlen (repository) + strlen (name) + 10); (void) sprintf (retval, "%s/%s", repository, name); } else { struct stat sb; mode_t new_mode = 0; /* The interesting part of the repository is the part relative to CVSROOT. */ assert (current_parsed_root != NULL); assert (current_parsed_root->directory != NULL); assert (strncmp (repository, current_parsed_root->directory, strlen (current_parsed_root->directory)) == 0); short_repos = repository + strlen (current_parsed_root->directory) + 1; if (strcmp (repository, current_parsed_root->directory) == 0) short_repos = "."; else assert (short_repos[-1] == '/'); retval = xmalloc (strlen (lock_dir) + strlen (short_repos) + strlen (name) + 10); strcpy (retval, lock_dir); q = retval + strlen (retval); *q++ = '/'; strcpy (q, short_repos); /* In the common case, where the directory already exists, let's keep it to one system call. */ if (CVS_STAT (retval, &sb) < 0) { /* If we need to be creating more than one directory, we'll get the existence_error here. */ if (!existence_error (errno)) error (1, errno, "cannot stat directory %s", retval); } else { if (S_ISDIR (sb.st_mode)) goto created; else error (1, 0, "%s is not a directory", retval); } /* Now add the directories one at a time, so we can create them if needed. The idea behind the new_mode stuff is that the directory we end up creating will inherit permissions from its parent directory (we re-set new_mode with each EEXIST). CVSUMASK isn't right, because typically the reason for LockDir is to use a different set of permissions. We probably want to inherit group ownership also (but we don't try to deal with that, some systems do it for us either always or when g+s is on). We don't try to do anything about the permissions on the lock files themselves. The permissions don't really matter so much because the locks will generally be removed by the process which created them. */ if (CVS_STAT (lock_dir, &sb) < 0) error (1, errno, "cannot stat %s", lock_dir); new_mode = sb.st_mode; save_umask = umask (0000); saved_umask = 1; p = short_repos; while (1) { while (!ISDIRSEP (*p) && *p != '\0') ++p; if (ISDIRSEP (*p)) { strncpy (q, short_repos, p - short_repos); q[p - short_repos] = '\0'; if (!ISDIRSEP (q[p - short_repos - 1]) && CVS_MKDIR (retval, new_mode) < 0) { int saved_errno = errno; if (saved_errno != EEXIST) error (1, errno, "cannot make directory %s", retval); else { if (CVS_STAT (retval, &sb) < 0) error (1, errno, "cannot stat %s", retval); new_mode = sb.st_mode; } } ++p; } else { strcpy (q, short_repos); if (CVS_MKDIR (retval, new_mode) < 0 && errno != EEXIST) error (1, errno, "cannot make directory %s", retval); goto created; } } created:; strcat (retval, "/"); strcat (retval, name); if (saved_umask) { assert (umask (save_umask) == 0000); saved_umask = 0; } } return retval; } /* * Clean up all outstanding locks */ void Lock_Cleanup () { /* FIXME: error handling here is kind of bogus; we sometimes will call error, which in turn can call us again. For the moment work around this by refusing to reenter this function (this is a kludge). */ /* FIXME-reentrancy: the workaround isn't reentrant. */ static int in_lock_cleanup = 0; if (trace) (void) fprintf (stderr, "%s-> Lock_Cleanup()\n", CLIENT_SERVER_STR); if (in_lock_cleanup) return; in_lock_cleanup = 1; remove_locks (); dellist (&lock_tree_list); if (locked_dir != NULL) { dellist (&locked_list); free (locked_dir); locked_dir = NULL; locked_list = NULL; } if (global_history_lock.repository) clear_history_lock (); if (global_val_tags_lock.repository) clear_val_tags_lock (); in_lock_cleanup = 0; } /* * Remove locks without discarding the lock information */ static void remove_locks () { /* clean up simple locks (if any) */ if (global_readlock.repository != NULL) { lock_simple_remove (&global_readlock); global_readlock.repository = NULL; } /* clean up multiple locks (if any) */ if (locklist != (List *) NULL) { (void) walklist (locklist, unlock_proc, NULL); locklist = (List *) NULL; } } /* * walklist proc for removing a list of locks */ static int unlock_proc (p, closure) Node *p; void *closure; { lock_simple_remove (p->data); return (0); } /* Remove the lock files. */ static void lock_simple_remove (lock) struct lock *lock; { char *tmp; /* If readlock is set, the lock directory *might* have been created, but since Reader_Lock doesn't use SIG_beginCrSect the way that set_lock does, we don't know that. That is why we need to check for existence_error here. */ if (readlock != NULL) { tmp = lock_name (lock->repository, readlock); if (CVS_UNLINK (tmp) < 0 && ! existence_error (errno)) error (0, errno, "failed to remove lock %s", tmp); free (tmp); } /* If writelock is set, the lock directory *might* have been created, but since write_lock doesn't use SIG_beginCrSect the way that set_lock does, we don't know that. That is why we need to check for existence_error here. */ if (writelock != NULL) { tmp = lock_name (lock->repository, writelock); if (CVS_UNLINK (tmp) < 0 && ! existence_error (errno)) error (0, errno, "failed to remove lock %s", tmp); free (tmp); } clear_lock (lock); } /* * Create a lock file for readers */ int Reader_Lock (xrepository) char *xrepository; { int err = 0; FILE *fp; char *tmp; if (trace) (void) fprintf (stderr, "%s-> Reader_Lock(%s)\n", CLIENT_SERVER_STR, xrepository); if (noexec || readonlyfs) return 0; /* we only do one directory at a time for read locks! */ if (global_readlock.repository != NULL) { error (0, 0, "Reader_Lock called while read locks set - Help!"); return 1; } if (readlock == NULL) { readlock = xmalloc (strlen (hostname) + sizeof (CVSRFL) + 40); (void) sprintf (readlock, #ifdef HAVE_LONG_FILE_NAMES "%s.%s.%ld", CVSRFL, hostname, #else "%s.%ld", CVSRFL, #endif (long) getpid ()); } /* remember what we're locking (for Lock_Cleanup) */ global_readlock.repository = xrepository; /* get the lock dir for our own */ if (set_lock (&global_readlock, 1) != L_OK) { error (0, 0, "failed to obtain dir lock in repository `%s'", xrepository); if (readlock != NULL) free (readlock); readlock = NULL; /* We don't set global_readlock.repository to NULL. I think this only works because recurse.c will give a fatal error if we return a nonzero value. */ return 1; } /* write a read-lock */ tmp = lock_name (xrepository, readlock); if ((fp = CVS_FOPEN (tmp, "w+")) == NULL || fclose (fp) == EOF) { error (0, errno, "cannot create read lock in repository `%s'", xrepository); if (readlock != NULL) free (readlock); readlock = NULL; err = 1; } free (tmp); /* free the lock dir */ clear_lock (&global_readlock); return err; } /* * Lock a list of directories for writing */ static char *lock_error_repos; static int lock_error; static int Writer_Lock PROTO ((List * list)); static int Writer_Lock (list) List *list; { char *wait_repos; if (noexec) return 0; if (readonlyfs) { error (0, 0, "write lock failed - read-only repository"); return (1); } /* We only know how to do one list at a time */ if (locklist != (List *) NULL) { error (0, 0, "Writer_Lock called while write locks set - Help!"); return 1; } wait_repos = NULL; for (;;) { /* try to lock everything on the list */ lock_error = L_OK; /* init for set_writelock_proc */ lock_error_repos = (char *) NULL; /* init for set_writelock_proc */ locklist = list; /* init for Lock_Cleanup */ if (lockers_name != NULL) free (lockers_name); lockers_name = xstrdup ("unknown"); (void) walklist (list, set_writelock_proc, NULL); switch (lock_error) { case L_ERROR: /* Real Error */ if (wait_repos != NULL) free (wait_repos); Lock_Cleanup (); /* clean up any locks we set */ error (0, 0, "lock failed - giving up"); return 1; case L_LOCKED: /* Someone already had a lock */ remove_locks (); /* clean up any locks we set */ lock_wait (lock_error_repos); /* sleep a while and try again */ wait_repos = xstrdup (lock_error_repos); continue; case L_OK: /* we got the locks set */ if (wait_repos != NULL) { lock_obtained (wait_repos); free (wait_repos); } return 0; default: if (wait_repos != NULL) free (wait_repos); error (0, 0, "unknown lock status %d in Writer_Lock", lock_error); return 1; } } } /* * walklist proc for setting write locks */ static int set_writelock_proc (p, closure) Node *p; void *closure; { /* if some lock was not OK, just skip this one */ if (lock_error != L_OK) return 0; /* apply the write lock */ lock_error_repos = p->key; lock_error = write_lock (p->data); return 0; } /* * Create a lock file for writers returns L_OK if lock set ok, L_LOCKED if * lock held by someone else or L_ERROR if an error occurred */ static int write_lock (lock) struct lock *lock; { int status; FILE *fp; char *tmp; if (trace) (void) fprintf (stderr, "%s-> write_lock(%s)\n", CLIENT_SERVER_STR, lock->repository); if (writelock == NULL) { writelock = xmalloc (strlen (hostname) + sizeof (CVSWFL) + 40); (void) sprintf (writelock, #ifdef HAVE_LONG_FILE_NAMES "%s.%s.%ld", CVSWFL, hostname, #else "%s.%ld", CVSWFL, #endif (long) getpid()); } /* make sure the lock dir is ours (not necessarily unique to us!) */ status = set_lock (lock, 0); if (status == L_OK) { /* we now own a writer - make sure there are no readers */ if (readers_exist (lock->repository)) { /* clean up the lock dir if we created it */ if (status == L_OK) { clear_lock (lock); } /* indicate we failed due to read locks instead of error */ return L_LOCKED; } /* write the write-lock file */ tmp = lock_name (lock->repository, writelock); if ((fp = CVS_FOPEN (tmp, "w+")) == NULL || fclose (fp) == EOF) { int xerrno = errno; if ( CVS_UNLINK (tmp) < 0 && ! existence_error (errno)) error (0, errno, "failed to remove lock %s", tmp); /* free the lock dir if we created it */ if (status == L_OK) { clear_lock (lock); } /* return the error */ error (0, xerrno, "cannot create write lock in repository `%s'", lock->repository); free (tmp); return L_ERROR; } free (tmp); return L_OK; } else return status; } /* * readers_exist() returns 0 if there are no reader lock files remaining in * the repository; else 1 is returned, to indicate that the caller should * sleep a while and try again. */ static int readers_exist (repository) char *repository; { char *lockdir; char *line; DIR *dirp; struct dirent *dp; struct stat sb; int ret; #ifdef CVS_FUDGELOCKS time_t now; (void)time (&now); #endif lockdir = lock_name (repository, ""); assert (lockdir != NULL); lockdir[strlen (lockdir) - 1] = '\0'; /* remove trailing slash */ do { if ((dirp = CVS_OPENDIR (lockdir)) == NULL) error (1, 0, "cannot open directory %s", lockdir); ret = 0; errno = 0; while ((dp = CVS_READDIR (dirp)) != NULL) { if (CVS_FNMATCH (CVSRFLPAT, dp->d_name, 0) == 0) { line = xmalloc (strlen (lockdir) + 1 + strlen (dp->d_name) + 1); (void)sprintf (line, "%s/%s", lockdir, dp->d_name); if (CVS_STAT (line, &sb) != -1) { #ifdef CVS_FUDGELOCKS /* * If the create time of the file is more than CVSLCKAGE * seconds ago, try to clean-up the lock file, and if * successful, re-open the directory and try again. */ if (now >= (sb.st_ctime + CVSLCKAGE) && CVS_UNLINK (line) != -1) { free (line); ret = -1; break; } #endif set_lockers_name (&sb); } else { /* If the file doesn't exist, it just means that it * disappeared between the time we did the readdir and the * time we did the stat. */ if (!existence_error (errno)) error (0, errno, "cannot stat %s", line); } errno = 0; free (line); ret = 1; break; } errno = 0; } if (errno != 0) error (0, errno, "error reading directory %s", repository); CVS_CLOSEDIR (dirp); } while (ret < 0); if (lockdir != NULL) free (lockdir); return ret; } /* * Set the static variable lockers_name appropriately, based on the stat * structure passed in. */ static void set_lockers_name (statp) struct stat *statp; { struct passwd *pw; if (lockers_name != NULL) free (lockers_name); if ((pw = (struct passwd *)getpwuid (statp->st_uid)) != (struct passwd *)NULL) { lockers_name = xstrdup (pw->pw_name); } else { lockers_name = xmalloc (20); (void)sprintf (lockers_name, "uid%lu", (unsigned long) statp->st_uid); } } /* * Persistently tries to make the directory "lckdir", which serves as a * lock. * * #ifdef CVS_FUDGELOCKS * If the create time on the directory is greater than CVSLCKAGE * seconds old, just try to remove the directory. * #endif * */ static int set_lock (lock, will_wait) struct lock *lock; int will_wait; { int waited; long us; struct stat sb; mode_t omask; char *masterlock; int status; #ifdef CVS_FUDGELOCKS time_t now; #endif masterlock = lock_name (lock->repository, lock->lockdirname); /* * Note that it is up to the callers of set_lock() to arrange for signal * handlers that do the appropriate things, like remove the lock * directory before they exit. */ waited = 0; us = 1; for (;;) { status = -1; omask = umask (cvsumask); SIG_beginCrSect (); if (CVS_MKDIR (masterlock, 0777) == 0) { lock->lockdir = masterlock; SIG_endCrSect (); status = L_OK; if (waited) lock_obtained (lock->repository); goto after_sig_unblock; } SIG_endCrSect (); after_sig_unblock: (void) umask (omask); if (status != -1) goto done; if (errno != EEXIST) { error (0, errno, "failed to create lock directory for `%s' (%s)", lock->repository, masterlock); status = L_ERROR; goto done; } /* Find out who owns the lock. If the lock directory is non-existent, re-try the loop since someone probably just removed it (thus releasing the lock). */ if (CVS_STAT (masterlock, &sb) < 0) { if (existence_error (errno)) continue; error (0, errno, "couldn't stat lock directory `%s'", masterlock); status = L_ERROR; goto done; } #ifdef CVS_FUDGELOCKS /* * If the create time of the directory is more than CVSLCKAGE seconds * ago, try to clean-up the lock directory, and if successful, just * quietly retry to make it. */ (void) time (&now); if (now >= (sb.st_ctime + CVSLCKAGE)) { if (CVS_RMDIR (masterlock) >= 0) continue; } #endif /* set the lockers name */ set_lockers_name (&sb); /* if he wasn't willing to wait, return an error */ if (!will_wait) { status = L_LOCKED; goto done; } /* if possible, try a very short sleep without a message */ if (!waited && us < 1000) { us += us; #if defined HAVE_NANOSLEEP { struct timespec ts; ts.tv_sec = 0; ts.tv_nsec = us * 1000; (void)nanosleep (&ts, NULL); continue; } #elif defined HAVE_USLEEP (void)usleep (us); continue; #elif defined HAVE_SELECT { struct timeval tv; tv.tv_sec = 0; tv.tv_usec = us; (void)select (0, (fd_set *)NULL, (fd_set *)NULL, (fd_set *)NULL, &tv); continue; } #endif } lock_wait (lock->repository); waited = 1; } done: if (!lock->lockdir) free (masterlock); return status; } /* * Clear master lock. * * INPUTS * lock The lock information. * * OUTPUTS * Sets LOCK->lockdir to NULL after removing the directory it names and * freeing the storage. * * ASSUMPTIONS * If we own the master lock directory, its name is stored in LOCK->lockdir. * We may free LOCK->lockdir. * */ static void clear_lock (lock) struct lock *lock; { SIG_beginCrSect (); if (lock->lockdir) { if (CVS_RMDIR (lock->lockdir) < 0) error (0, errno, "failed to remove lock dir `%s'", lock->lockdir); free (lock->lockdir); lock->lockdir = NULL; } SIG_endCrSect (); } /* * Print out a message that the lock is still held, then sleep a while. */ static void lock_wait (repos) char *repos; { time_t now; char *msg; struct tm *tm_p; (void) time (&now); tm_p = gmtime (&now); msg = xmalloc (100 + strlen (lockers_name) + strlen (repos)); sprintf (msg, "[%8.8s] waiting for %s's lock in %s", (tm_p ? asctime (tm_p) : ctime (&now)) + 11, lockers_name, repos); error (0, 0, "%s", msg); /* Call cvs_flusherr to ensure that the user sees this message as soon as possible. */ cvs_flusherr (); free (msg); (void) sleep (CVSLCKSLEEP); } /* * Print out a message when we obtain a lock. */ static void lock_obtained (repos) char *repos; { time_t now; char *msg; struct tm *tm_p; (void) time (&now); tm_p = gmtime (&now); msg = xmalloc (100 + strlen (repos)); sprintf (msg, "[%8.8s] obtained lock in %s", (tm_p ? asctime (tm_p) : ctime (&now)) + 11, repos); error (0, 0, "%s", msg); /* Call cvs_flusherr to ensure that the user sees this message as soon as possible. */ cvs_flusherr (); free (msg); } static int lock_filesdoneproc PROTO ((void *callerdat, int err, const char *repository, const char *update_dir, List *entries)); /* * Create a list of repositories to lock */ /* ARGSUSED */ static int lock_filesdoneproc (callerdat, err, repository, update_dir, entries) void *callerdat; int err; const char *repository; const char *update_dir; List *entries; { Node *p; p = getnode (); p->type = LOCK; p->key = xstrdup (repository); p->data = xmalloc (sizeof (struct lock)); ((struct lock *)p->data)->repository = p->key; ((struct lock *)p->data)->lockdirname = CVSLCK; ((struct lock *)p->data)->lockdir = NULL; /* FIXME-KRP: this error condition should not simply be passed by. */ if (p->key == NULL || addnode (lock_tree_list, p) != 0) freenode (p); return (err); } void lock_tree_for_write (argc, argv, local, which, aflag) int argc; char **argv; int local; int which; int aflag; { /* * Run the recursion processor to find all the dirs to lock and lock all * the dirs */ lock_tree_list = getlist (); start_recursion ((FILEPROC) NULL, lock_filesdoneproc, (DIRENTPROC) NULL, (DIRLEAVEPROC) NULL, NULL, argc, argv, local, which, aflag, CVS_LOCK_NONE, (char *) NULL, 0, (char *) NULL); sortlist (lock_tree_list, fsortcmp); if (Writer_Lock (lock_tree_list) != 0) error (1, 0, "lock failed - giving up"); } /* Lock a single directory in REPOSITORY. It is OK to call this if a lock has been set with lock_dir_for_write; the new lock will replace the old one. If REPOSITORY is NULL, don't do anything. */ void lock_dir_for_write (repository) char *repository; { if (repository != NULL && (locked_dir == NULL || strcmp (locked_dir, repository) != 0)) { Node *node; if (locked_dir != NULL) Lock_Cleanup (); locked_dir = xstrdup (repository); locked_list = getlist (); node = getnode (); node->type = LOCK; node->key = xstrdup (repository); node->data = xmalloc (sizeof (struct lock)); ((struct lock *)node->data)->repository = node->key; ((struct lock *)node->data)->lockdirname = CVSLCK; ((struct lock *)node->data)->lockdir = NULL; (void) addnode (locked_list, node); Writer_Lock (locked_list); } } /* This is the internal implementation behind history_lock & val_tags_lock. It * gets a write lock for the history or val-tags file. * * RETURNS * true, on success * false, on error */ static int internal_lock PROTO ((struct lock *lock, const char *xrepository)); static int internal_lock (lock, xrepository) struct lock *lock; const char *xrepository; { /* remember what we're locking (for Lock_Cleanup) */ assert (!lock->repository); lock->repository = xmalloc (strlen (xrepository) + sizeof (CVSROOTADM) + 2); sprintf (lock->repository, "%s/%s", xrepository, CVSROOTADM); /* get the lock dir for our own */ if (set_lock (lock, 1) != L_OK) { if (!really_quiet) error (0, 0, "failed to obtain history lock in repository `%s'", xrepository); return 0; } return 1; } /* This is the internal implementation behind history_lock & val_tags_lock. It * removes the write lock for the history or val-tags file, when it exists. */ static void internal_clear_lock PROTO((struct lock *lock)); static void internal_clear_lock (lock) struct lock *lock; { SIG_beginCrSect (); if (lock->repository) { free (lock->repository); lock->repository = NULL; } SIG_endCrSect (); clear_lock (lock); } /* Lock the CVSROOT/history file for write. */ int history_lock (xrepository) const char *xrepository; { return internal_lock (&global_history_lock, xrepository); } /* Remove the CVSROOT/history lock, if it exists. */ void clear_history_lock () { internal_clear_lock (&global_history_lock); } /* Lock the CVSROOT/val-tags file for write. */ int val_tags_lock (xrepository) const char *xrepository; { return internal_lock (&global_val_tags_lock, xrepository); } /* Remove the CVSROOT/val-tags lock, if it exists. */ void clear_val_tags_lock () { internal_clear_lock (&global_val_tags_lock); }