X-Git-Url: http://git.ozlabs.org/?a=blobdiff_plain;f=ccan%2Ftdb2%2Flock.c;h=82fcdf17d1e6dfd0126d17232826cc53391329ee;hb=2960e90f2d036935273d163593839d3777be7980;hp=b57c53449466437c7cdd16cdc21ff4c67866b8a9;hpb=a39bf3aca1b60365efaf8b1eeb2b2c58b09ffab6;p=ccan diff --git a/ccan/tdb2/lock.c b/ccan/tdb2/lock.c index b57c5344..82fcdf17 100644 --- a/ccan/tdb2/lock.c +++ b/ccan/tdb2/lock.c @@ -29,6 +29,17 @@ #include #include +/* If we were threaded, we could wait for unlock, but we're not, so fail. */ +static bool owner_conflict(struct tdb_context *tdb, struct tdb_lock *lock) +{ + if (lock->owner != tdb) { + tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_USE_ERROR, + "Lock already owned by another opener"); + return true; + } + return false; +} + static int fcntl_lock(struct tdb_context *tdb, int rw, off_t off, off_t len, bool waitflag) { @@ -42,10 +53,10 @@ static int fcntl_lock(struct tdb_context *tdb, add_stat(tdb, lock_lowlevel, 1); if (waitflag) - return fcntl(tdb->fd, F_SETLKW, &fl); + return fcntl(tdb->file->fd, F_SETLKW, &fl); else { add_stat(tdb, lock_nonblock, 1); - return fcntl(tdb->fd, F_SETLK, &fl); + return fcntl(tdb->file->fd, F_SETLK, &fl); } } @@ -116,11 +127,11 @@ static int fcntl_unlock(struct tdb_context *tdb, int rw, off_t off, off_t len) fl.l_len = len; fl.l_pid = 0; - return fcntl(tdb->fd, F_SETLKW, &fl); + return fcntl(tdb->file->fd, F_SETLKW, &fl); } /* a byte range locking function - return 0 on success - this functions locks/unlocks 1 byte at the specified offset. + this functions locks len bytes at the specified offset. note that a len of zero means lock to end of file */ @@ -161,7 +172,7 @@ static enum TDB_ERROR tdb_brlock(struct tdb_context *tdb, "tdb_brlock failed (fd=%d) at" " offset %zu rw_type=%d flags=%d len=%zu:" " %s", - tdb->fd, (size_t)offset, rw_type, + tdb->file->fd, (size_t)offset, rw_type, flags, (size_t)len, strerror(errno)); } return TDB_ERR_LOCK; @@ -186,7 +197,7 @@ static enum TDB_ERROR tdb_brunlock(struct tdb_context *tdb, return tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_ERROR, "tdb_brunlock failed (fd=%d) at offset %zu" " rw_type=%d len=%zu", - tdb->fd, (size_t)offset, rw_type, + tdb->file->fd, (size_t)offset, rw_type, (size_t)len); } return TDB_SUCCESS; @@ -202,14 +213,14 @@ enum TDB_ERROR tdb_allrecord_upgrade(struct tdb_context *tdb) { int count = 1000; - if (tdb->allrecord_lock.count != 1) { + if (tdb->file->allrecord_lock.count != 1) { return tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_ERROR, "tdb_allrecord_upgrade failed:" " count %u too high", - tdb->allrecord_lock.count); + tdb->file->allrecord_lock.count); } - if (tdb->allrecord_lock.off != 1) { + if (tdb->file->allrecord_lock.off != 1) { return tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_ERROR, "tdb_allrecord_upgrade failed:" " already upgraded?"); @@ -220,8 +231,8 @@ enum TDB_ERROR tdb_allrecord_upgrade(struct tdb_context *tdb) if (tdb_brlock(tdb, F_WRLCK, TDB_HASH_LOCK_START, 0, TDB_LOCK_WAIT|TDB_LOCK_PROBE) == TDB_SUCCESS) { - tdb->allrecord_lock.ltype = F_WRLCK; - tdb->allrecord_lock.off = 0; + tdb->file->allrecord_lock.ltype = F_WRLCK; + tdb->file->allrecord_lock.off = 0; return TDB_SUCCESS; } if (errno != EDEADLK) { @@ -236,14 +247,16 @@ enum TDB_ERROR tdb_allrecord_upgrade(struct tdb_context *tdb) "tdb_allrecord_upgrade failed"); } -static struct tdb_lock_type *find_nestlock(struct tdb_context *tdb, - tdb_off_t offset) +static struct tdb_lock *find_nestlock(struct tdb_context *tdb, tdb_off_t offset, + const struct tdb_context *owner) { unsigned int i; - for (i=0; inum_lockrecs; i++) { - if (tdb->lockrecs[i].off == offset) { - return &tdb->lockrecs[i]; + for (i=0; ifile->num_lockrecs; i++) { + if (tdb->file->lockrecs[i].off == offset) { + if (owner && tdb->file->lockrecs[i].owner != owner) + return NULL; + return &tdb->file->lockrecs[i]; } } return NULL; @@ -276,10 +289,11 @@ static enum TDB_ERROR tdb_nest_lock(struct tdb_context *tdb, tdb_off_t offset, int ltype, enum tdb_lock_flags flags) { - struct tdb_lock_type *new_lck; + struct tdb_lock *new_lck; enum TDB_ERROR ecode; - if (offset > TDB_HASH_LOCK_START + TDB_HASH_LOCK_RANGE + tdb->map_size / 8) { + if (offset > (TDB_HASH_LOCK_START + TDB_HASH_LOCK_RANGE + + tdb->file->map_size / 8)) { return tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_ERROR, "tdb_nest_lock: invalid offset %zu ltype=%d", (size_t)offset, ltype); @@ -290,8 +304,11 @@ static enum TDB_ERROR tdb_nest_lock(struct tdb_context *tdb, add_stat(tdb, locks, 1); - new_lck = find_nestlock(tdb, offset); + new_lck = find_nestlock(tdb, offset, NULL); if (new_lck) { + if (owner_conflict(tdb, new_lck)) + return -1; + if (new_lck->ltype == F_RDLCK && ltype == F_WRLCK) { return tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_ERROR, "tdb_nest_lock:" @@ -303,23 +320,23 @@ static enum TDB_ERROR tdb_nest_lock(struct tdb_context *tdb, return TDB_SUCCESS; } - if (tdb->num_lockrecs + if (tdb->file->num_lockrecs && offset >= TDB_HASH_LOCK_START && offset < TDB_HASH_LOCK_START + TDB_HASH_LOCK_RANGE) { return tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_ERROR, "tdb_nest_lock: already have a hash lock?"); } - new_lck = (struct tdb_lock_type *)realloc( - tdb->lockrecs, - sizeof(*tdb->lockrecs) * (tdb->num_lockrecs+1)); + new_lck = (struct tdb_lock *)realloc( + tdb->file->lockrecs, + sizeof(*tdb->file->lockrecs) * (tdb->file->num_lockrecs+1)); if (new_lck == NULL) { return tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR, "tdb_nest_lock:" " unable to allocate %zu lock struct", - tdb->num_lockrecs + 1); + tdb->file->num_lockrecs + 1); } - tdb->lockrecs = new_lck; + tdb->file->lockrecs = new_lck; /* Since fcntl locks don't nest, we do a lock for the first one, and simply bump the count for future ones */ @@ -330,7 +347,7 @@ static enum TDB_ERROR tdb_nest_lock(struct tdb_context *tdb, /* First time we grab a lock, perhaps someone died in commit? */ if (!(flags & TDB_LOCK_NOCHECK) - && tdb->num_lockrecs == 0) { + && tdb->file->num_lockrecs == 0) { tdb_bool_err berr = tdb_needs_recovery(tdb); if (berr != false) { tdb_brunlock(tdb, ltype, offset, 1); @@ -348,10 +365,11 @@ static enum TDB_ERROR tdb_nest_lock(struct tdb_context *tdb, } } - tdb->lockrecs[tdb->num_lockrecs].off = offset; - tdb->lockrecs[tdb->num_lockrecs].count = 1; - tdb->lockrecs[tdb->num_lockrecs].ltype = ltype; - tdb->num_lockrecs++; + tdb->file->lockrecs[tdb->file->num_lockrecs].owner = tdb; + tdb->file->lockrecs[tdb->file->num_lockrecs].off = offset; + tdb->file->lockrecs[tdb->file->num_lockrecs].count = 1; + tdb->file->lockrecs[tdb->file->num_lockrecs].ltype = ltype; + tdb->file->num_lockrecs++; return TDB_SUCCESS; } @@ -359,13 +377,13 @@ static enum TDB_ERROR tdb_nest_lock(struct tdb_context *tdb, static enum TDB_ERROR tdb_nest_unlock(struct tdb_context *tdb, tdb_off_t off, int ltype) { - struct tdb_lock_type *lck; + struct tdb_lock *lck; enum TDB_ERROR ecode; if (tdb->flags & TDB_NOLOCK) return TDB_SUCCESS; - lck = find_nestlock(tdb, off); + lck = find_nestlock(tdb, off, tdb); if ((lck == NULL) || (lck->count == 0)) { return tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_ERROR, "tdb_nest_unlock: no lock for %zu", @@ -389,7 +407,7 @@ static enum TDB_ERROR tdb_nest_unlock(struct tdb_context *tdb, * Shrink the array by overwriting the element just unlocked with the * last array element. */ - *lck = tdb->lockrecs[--tdb->num_lockrecs]; + *lck = tdb->file->lockrecs[--tdb->file->num_lockrecs]; return ecode; } @@ -452,17 +470,18 @@ enum TDB_ERROR tdb_allrecord_lock(struct tdb_context *tdb, int ltype, enum TDB_ERROR ecode; tdb_bool_err berr; - if (tdb->allrecord_lock.count - && (ltype == F_RDLCK || tdb->allrecord_lock.ltype == F_WRLCK)) { - tdb->allrecord_lock.count++; + if (tdb->file->allrecord_lock.count + && (ltype == F_RDLCK + || tdb->file->allrecord_lock.ltype == F_WRLCK)) { + tdb->file->allrecord_lock.count++; return TDB_SUCCESS; } - if (tdb->allrecord_lock.count) { + if (tdb->file->allrecord_lock.count) { /* a global lock of a different type exists */ return tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_USE_ERROR, "tdb_allrecord_lock: already have %s lock", - tdb->allrecord_lock.ltype == F_RDLCK + tdb->file->allrecord_lock.ltype == F_RDLCK ? "read" : "write"); } @@ -507,11 +526,12 @@ again: return ecode; } - tdb->allrecord_lock.count = 1; + tdb->file->allrecord_lock.owner = tdb; + tdb->file->allrecord_lock.count = 1; /* If it's upgradable, it's actually exclusive so we can treat * it as a write lock. */ - tdb->allrecord_lock.ltype = upgradable ? F_WRLCK : ltype; - tdb->allrecord_lock.off = upgradable; + tdb->file->allrecord_lock.ltype = upgradable ? F_WRLCK : ltype; + tdb->file->allrecord_lock.off = upgradable; /* Now check for needing recovery. */ if (flags & TDB_LOCK_NOCHECK) @@ -543,7 +563,8 @@ void tdb_unlock_open(struct tdb_context *tdb) bool tdb_has_open_lock(struct tdb_context *tdb) { - return find_nestlock(tdb, TDB_OPEN_LOCK) != NULL; + return !(tdb->flags & TDB_NOLOCK) + && find_nestlock(tdb, TDB_OPEN_LOCK, tdb) != NULL; } enum TDB_ERROR tdb_lock_expand(struct tdb_context *tdb, int ltype) @@ -561,46 +582,52 @@ void tdb_unlock_expand(struct tdb_context *tdb, int ltype) /* unlock entire db */ void tdb_allrecord_unlock(struct tdb_context *tdb, int ltype) { - if (tdb->allrecord_lock.count == 0) { + if (tdb->file->allrecord_lock.count == 0) { tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_USE_ERROR, "tdb_allrecord_unlock: not locked!"); return; } + if (tdb->file->allrecord_lock.owner != tdb) { + tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_USE_ERROR, + "tdb_allrecord_unlock: not locked by us!"); + return; + } + /* Upgradable locks are marked as write locks. */ - if (tdb->allrecord_lock.ltype != ltype - && (!tdb->allrecord_lock.off || ltype != F_RDLCK)) { + if (tdb->file->allrecord_lock.ltype != ltype + && (!tdb->file->allrecord_lock.off || ltype != F_RDLCK)) { tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_ERROR, "tdb_allrecord_unlock: have %s lock", - tdb->allrecord_lock.ltype == F_RDLCK + tdb->file->allrecord_lock.ltype == F_RDLCK ? "read" : "write"); return; } - if (tdb->allrecord_lock.count > 1) { - tdb->allrecord_lock.count--; + if (tdb->file->allrecord_lock.count > 1) { + tdb->file->allrecord_lock.count--; return; } - tdb->allrecord_lock.count = 0; - tdb->allrecord_lock.ltype = 0; + tdb->file->allrecord_lock.count = 0; + tdb->file->allrecord_lock.ltype = 0; tdb_brunlock(tdb, ltype, TDB_HASH_LOCK_START, 0); } bool tdb_has_expansion_lock(struct tdb_context *tdb) { - return find_nestlock(tdb, TDB_EXPANSION_LOCK) != NULL; + return find_nestlock(tdb, TDB_EXPANSION_LOCK, tdb) != NULL; } bool tdb_has_hash_locks(struct tdb_context *tdb) { unsigned int i; - for (i=0; inum_lockrecs; i++) { - if (tdb->lockrecs[i].off >= TDB_HASH_LOCK_START - && tdb->lockrecs[i].off < (TDB_HASH_LOCK_START - + TDB_HASH_LOCK_RANGE)) + for (i=0; ifile->num_lockrecs; i++) { + if (tdb->file->lockrecs[i].off >= TDB_HASH_LOCK_START + && tdb->file->lockrecs[i].off < (TDB_HASH_LOCK_START + + TDB_HASH_LOCK_RANGE)) return true; } return false; @@ -610,8 +637,11 @@ static bool tdb_has_free_lock(struct tdb_context *tdb) { unsigned int i; - for (i=0; inum_lockrecs; i++) { - if (tdb->lockrecs[i].off + if (tdb->flags & TDB_NOLOCK) + return false; + + for (i=0; ifile->num_lockrecs; i++) { + if (tdb->file->lockrecs[i].off > TDB_HASH_LOCK_START + TDB_HASH_LOCK_RANGE) return true; } @@ -628,16 +658,16 @@ enum TDB_ERROR tdb_lock_hashes(struct tdb_context *tdb, + (hash_lock >> (64 - TDB_HASH_LOCK_RANGE_BITS)); /* a allrecord lock allows us to avoid per chain locks */ - if (tdb->allrecord_lock.count && - (ltype == tdb->allrecord_lock.ltype || ltype == F_RDLCK)) { + if (tdb->file->allrecord_lock.count && + (ltype == tdb->file->allrecord_lock.ltype || ltype == F_RDLCK)) { return TDB_SUCCESS; } - if (tdb->allrecord_lock.count) { + if (tdb->file->allrecord_lock.count) { return tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_USE_ERROR, "tdb_lock_hashes:" " already have %s allrecordlock", - tdb->allrecord_lock.ltype == F_RDLCK + tdb->file->allrecord_lock.ltype == F_RDLCK ? "read" : "write"); } @@ -662,9 +692,12 @@ enum TDB_ERROR tdb_unlock_hashes(struct tdb_context *tdb, unsigned lock = TDB_HASH_LOCK_START + (hash_lock >> (64 - TDB_HASH_LOCK_RANGE_BITS)); + if (tdb->flags & TDB_NOLOCK) + return 0; + /* a allrecord lock allows us to avoid per chain locks */ - if (tdb->allrecord_lock.count) { - if (tdb->allrecord_lock.ltype == F_RDLCK + if (tdb->file->allrecord_lock.count) { + if (tdb->file->allrecord_lock.ltype == F_RDLCK && ltype == F_WRLCK) { return tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_ERROR, "tdb_unlock_hashes RO allrecord!"); @@ -691,9 +724,12 @@ enum TDB_ERROR tdb_lock_free_bucket(struct tdb_context *tdb, tdb_off_t b_off, { assert(b_off >= sizeof(struct tdb_header)); + if (tdb->flags & TDB_NOLOCK) + return 0; + /* a allrecord lock allows us to avoid per chain locks */ - if (tdb->allrecord_lock.count) { - if (tdb->allrecord_lock.ltype == F_WRLCK) + if (tdb->file->allrecord_lock.count) { + if (tdb->file->allrecord_lock.ltype == F_WRLCK) return 0; return tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_ERROR, "tdb_lock_free_bucket with" @@ -713,15 +749,27 @@ enum TDB_ERROR tdb_lock_free_bucket(struct tdb_context *tdb, tdb_off_t b_off, void tdb_unlock_free_bucket(struct tdb_context *tdb, tdb_off_t b_off) { - if (tdb->allrecord_lock.count) + if (tdb->file->allrecord_lock.count) return; tdb_nest_unlock(tdb, free_lock_off(b_off), F_WRLCK); } -void tdb_lock_init(struct tdb_context *tdb) +void tdb_unlock_all(struct tdb_context *tdb) { - tdb->num_lockrecs = 0; - tdb->lockrecs = NULL; - tdb->allrecord_lock.count = 0; + unsigned int i; + + while (tdb->file->allrecord_lock.count + && tdb->file->allrecord_lock.owner == tdb) { + tdb_allrecord_unlock(tdb, tdb->file->allrecord_lock.ltype); + } + + for (i=0; ifile->num_lockrecs; i++) { + if (tdb->file->lockrecs[i].owner == tdb) { + tdb_nest_unlock(tdb, + tdb->file->lockrecs[i].off, + tdb->file->lockrecs[i].ltype); + i--; + } + } }