read_write_all: avoid arithmetic on void pointers.

[ccan] / ccan / tdb2 / lock.c

diff --git a/ccan/tdb2/lock.c b/ccan/tdb2/lock.c
index 98570d7627e7a38272c4f72ebcf60edece5dadfd..17e80d70caef02610af5fc76efcefc1556f614c6 100644 (file)
--- a/ccan/tdb2/lock.c
+++ b/ccan/tdb2/lock.c
@@ -29,6 +29,14 @@
 #include <assert.h>
 #include <ccan/build_assert/build_assert.h>
 
+/* If we were threaded, we could wait for unlock, but we're not, so fail. */
+static enum TDB_ERROR owner_conflict(struct tdb_context *tdb, const char *call)
+{
+       return tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_USE_ERROR,
+                         "%s: lock owned by another tdb in this process.",
+                         call);
+}
+
 static int fcntl_lock(struct tdb_context *tdb,
                      int rw, off_t off, off_t len, bool waitflag)
 {
@@ -215,6 +223,10 @@ enum TDB_ERROR tdb_allrecord_upgrade(struct tdb_context *tdb)
                                  " already upgraded?");
        }
 
+       if (tdb->file->allrecord_lock.owner != tdb) {
+               return owner_conflict(tdb, "tdb_allrecord_upgrade");
+       }
+
        while (count--) {
                struct timeval tv;
                if (tdb_brlock(tdb, F_WRLCK,
@@ -236,13 +248,15 @@ 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; i<tdb->file->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];
                }
        }
@@ -276,10 +290,11 @@ 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 +305,12 @@ 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 (new_lck->owner != tdb) {
+                       return owner_conflict(tdb, "tdb_nest_lock");
+               }
+
                if (new_lck->ltype == F_RDLCK && ltype == F_WRLCK) {
                        return tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_ERROR,
                                          "tdb_nest_lock:"
@@ -310,7 +329,7 @@ static enum TDB_ERROR tdb_nest_lock(struct tdb_context *tdb,
                                  "tdb_nest_lock: already have a hash lock?");
        }
 
-       new_lck = (struct tdb_lock_type *)realloc(
+       new_lck = (struct tdb_lock *)realloc(
                tdb->file->lockrecs,
                sizeof(*tdb->file->lockrecs) * (tdb->file->num_lockrecs+1));
        if (new_lck == NULL) {
@@ -348,6 +367,7 @@ static enum TDB_ERROR tdb_nest_lock(struct tdb_context *tdb,
                }
        }
 
+       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;
@@ -359,13 +379,13 @@ 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",
@@ -452,14 +472,17 @@ enum TDB_ERROR tdb_allrecord_lock(struct tdb_context *tdb, int ltype,
        enum TDB_ERROR ecode;
        tdb_bool_err berr;
 
-       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->file->allrecord_lock.count) {
+               if (tdb->file->allrecord_lock.owner != tdb) {
+                       return owner_conflict(tdb, "tdb_allrecord_lock");
+               }
+
+               if (ltype == F_RDLCK
+                   || tdb->file->allrecord_lock.ltype == F_WRLCK) {
+                       tdb->file->allrecord_lock.count++;
+                       return TDB_SUCCESS;
+               }
+
                /* 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",
@@ -508,6 +531,7 @@ again:
                return ecode;
        }
 
+       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. */
@@ -545,7 +569,7 @@ void tdb_unlock_open(struct tdb_context *tdb)
 bool tdb_has_open_lock(struct tdb_context *tdb)
 {
        return !(tdb->flags & TDB_NOLOCK)
-               && find_nestlock(tdb, TDB_OPEN_LOCK) != NULL;
+               && find_nestlock(tdb, TDB_OPEN_LOCK, tdb) != NULL;
 }
 
 enum TDB_ERROR tdb_lock_expand(struct tdb_context *tdb, int ltype)
@@ -569,12 +593,18 @@ void tdb_allrecord_unlock(struct tdb_context *tdb, int ltype)
                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->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;
        }
@@ -592,7 +622,7 @@ void tdb_allrecord_unlock(struct tdb_context *tdb, int ltype)
 
 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)
@@ -633,12 +663,14 @@ 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->file->allrecord_lock.count &&
-           (ltype == tdb->file->allrecord_lock.ltype || ltype == F_RDLCK)) {
-               return TDB_SUCCESS;
-       }
-
        if (tdb->file->allrecord_lock.count) {
+               if (tdb->file->allrecord_lock.owner != tdb)
+                       return owner_conflict(tdb, "tdb_lock_hashes");
+               if (ltype == tdb->file->allrecord_lock.ltype
+                   || ltype == F_RDLCK) {
+                       return TDB_SUCCESS;
+               }
+
                return tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_USE_ERROR,
                                  "tdb_lock_hashes:"
                                  " already have %s allrecordlock",
@@ -729,3 +761,22 @@ void tdb_unlock_free_bucket(struct tdb_context *tdb, tdb_off_t b_off)
 
        tdb_nest_unlock(tdb, free_lock_off(b_off), F_WRLCK);
 }
+
+void tdb_unlock_all(struct tdb_context *tdb)
+{
+       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; i<tdb->file->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--;
+               }
+       }
+}