read_write_all: avoid arithmetic on void pointers.

[ccan] / ccan / tdb2 / open.c

diff --git a/ccan/tdb2/open.c b/ccan/tdb2/open.c
index 56f606664519ba286b0ffc1443d200480182fee7..f7d6b3c5f3e5dbe356d9b842fcb1c30c36e93800 100644 (file)
--- a/ccan/tdb2/open.c
+++ b/ccan/tdb2/open.c
@@ -1,4 +1,5 @@
 #include "private.h"
+#include <assert.h>
 
 /* all lock info, to detect double-opens (fcntl file don't nest!) */
 static struct tdb_file *files = NULL;
@@ -9,6 +10,7 @@ static struct tdb_file *find_file(dev_t device, ino_t ino)
 
        for (i = files; i; i = i->next) {
                if (i->device == device && i->inode == ino) {
+                       i->refcnt++;
                        break;
                }
        }
@@ -105,6 +107,7 @@ static enum TDB_ERROR tdb_new_database(struct tdb_context *tdb,
                                         tdb->hash_priv);
        newdb.hdr.recovery = 0;
        newdb.hdr.features_used = newdb.hdr.features_offered = TDB_FEATURE_MASK;
+       newdb.hdr.seqnum = 0;
        memset(newdb.hdr.reserved, 0, sizeof(newdb.hdr.reserved));
        /* Initial hashes are empty. */
        memset(newdb.hdr.hashtable, 0, sizeof(newdb.hdr.hashtable));
@@ -174,6 +177,7 @@ static enum TDB_ERROR tdb_new_file(struct tdb_context *tdb)
        tdb->file->num_lockrecs = 0;
        tdb->file->lockrecs = NULL;
        tdb->file->allrecord_lock.count = 0;
+       tdb->file->refcnt = 1;
        return TDB_SUCCESS;
 }
 
@@ -205,6 +209,7 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
        tdb->transaction = NULL;
        tdb->stats = NULL;
        tdb->access = NULL;
+       tdb->last_error = TDB_SUCCESS;
        tdb->file = NULL;
        tdb_hash_init(tdb);
        tdb_io_init(tdb);
@@ -240,7 +245,7 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
        }
 
        if (tdb_flags & ~(TDB_INTERNAL | TDB_NOLOCK | TDB_NOMMAP | TDB_CONVERT
-                         | TDB_NOSYNC)) {
+                         | TDB_NOSYNC | TDB_SEQNUM)) {
                ecode = tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
                                   "tdb_open: unknown flags %u", tdb_flags);
                goto fail;
@@ -273,6 +278,16 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
                if (ecode != TDB_SUCCESS) {
                        goto fail;
                }
+               if (name) {
+                       tdb->name = strdup(name);
+                       if (!tdb->name) {
+                               ecode = tdb_logerr(tdb, TDB_ERR_OOM,
+                                                  TDB_LOG_ERROR,
+                                                  "tdb_open: failed to"
+                                                  " allocate name");
+                               goto fail;
+                       }
+               }
                tdb_convert(tdb, &hdr.hash_seed, sizeof(hdr.hash_seed));
                tdb->hash_seed = hdr.hash_seed;
                tdb_ftable_init(tdb);
@@ -291,7 +306,7 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
                        tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
                                   "tdb_open: could not open file %s: %s",
                                   name, strerror(errno));
-                       goto fail;
+                       goto fail_errno;
                }
 
                /* on exec, don't inherit the fd */
@@ -303,7 +318,7 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
                        tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
                                   "tdb_open: could not stat open %s: %s",
                                   name, strerror(errno));
-                       goto fail;
+                       goto fail_errno;
                }
 
                ecode = tdb_new_file(tdb);
@@ -316,13 +331,6 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
                tdb->file->inode = st.st_ino;
                tdb->file->map_ptr = NULL;
                tdb->file->map_size = sizeof(struct tdb_header);
-       } else {
-               /* FIXME */
-               ecode = tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
-                                  "tdb_open: %s (%d,%d) is already open in"
-                                  " this process",
-                                  name, (int)st.st_dev, (int)st.st_ino);
-               goto fail;
        }
 
        /* ensure there is only one process initialising at once */
@@ -332,7 +340,7 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
        }
 
        /* If they used O_TRUNC, read will return 0. */
-       rlen = read(tdb->file->fd, &hdr, sizeof(hdr));
+       rlen = pread(tdb->file->fd, &hdr, sizeof(hdr), 0);
        if (rlen == 0 && (open_flags & O_CREAT)) {
                ecode = tdb_new_database(tdb, seed, &hdr);
                if (ecode != TDB_SUCCESS) {
@@ -416,51 +424,54 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
                goto fail;
        }
 
-       /* Add to linked list. */
-       files = tdb->file;
+       /* Add to linked list if we're new. */
+       if (tdb->file->refcnt == 1)
+               files = tdb->file;
        return tdb;
 
  fail:
        /* Map ecode to some logical errno. */
-       if (!saved_errno) {
-               switch (ecode) {
-               case TDB_ERR_CORRUPT:
-               case TDB_ERR_IO:
-                       saved_errno = EIO;
-                       break;
-               case TDB_ERR_LOCK:
-                       saved_errno = EWOULDBLOCK;
-                       break;
-               case TDB_ERR_OOM:
-                       saved_errno = ENOMEM;
-                       break;
-               case TDB_ERR_EINVAL:
-                       saved_errno = EINVAL;
-                       break;
-               default:
-                       saved_errno = EINVAL;
-                       break;
-               }
+       switch (ecode) {
+       case TDB_ERR_CORRUPT:
+       case TDB_ERR_IO:
+               saved_errno = EIO;
+               break;
+       case TDB_ERR_LOCK:
+               saved_errno = EWOULDBLOCK;
+               break;
+       case TDB_ERR_OOM:
+               saved_errno = ENOMEM;
+               break;
+       case TDB_ERR_EINVAL:
+               saved_errno = EINVAL;
+               break;
+       default:
+               saved_errno = EINVAL;
+               break;
        }
 
+fail_errno:
 #ifdef TDB_TRACE
        close(tdb->tracefd);
 #endif
-       free((char *)tdb->name);
+       free(cast_const(char *, tdb->name));
        if (tdb->file) {
                tdb_unlock_all(tdb);
-               if (tdb->file->map_ptr) {
-                       if (tdb->flags & TDB_INTERNAL) {
-                               free(tdb->file->map_ptr);
-                       } else
-                               tdb_munmap(tdb->file);
+               if (--tdb->file->refcnt == 0) {
+                       assert(tdb->file->num_lockrecs == 0);
+                       if (tdb->file->map_ptr) {
+                               if (tdb->flags & TDB_INTERNAL) {
+                                       free(tdb->file->map_ptr);
+                               } else
+                                       tdb_munmap(tdb->file);
+                       }
+                       if (close(tdb->file->fd) != 0)
+                               tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
+                                          "tdb_open: failed to close tdb fd"
+                                          " on error: %s", strerror(errno));
+                       free(tdb->file->lockrecs);
+                       free(tdb->file);
                }
-               if (close(tdb->file->fd) != 0)
-                       tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
-                                  "tdb_open: failed to close tdb fd"
-                                  " on error: %s", strerror(errno));
-               free(tdb->file->lockrecs);
-               free(tdb->file);
        }
 
        free(tdb);
@@ -484,20 +495,24 @@ int tdb_close(struct tdb_context *tdb)
                else
                        tdb_munmap(tdb->file);
        }
-       free((char *)tdb->name);
+       free(cast_const(char *, tdb->name));
        if (tdb->file) {
                struct tdb_file **i;
-               ret = close(tdb->file->fd);
 
-               /* Remove from files list */
-               for (i = &files; *i; i = &(*i)->next) {
-                       if (*i == tdb->file) {
-                               *i = tdb->file->next;
-                               break;
+               tdb_unlock_all(tdb);
+               if (--tdb->file->refcnt == 0) {
+                       ret = close(tdb->file->fd);
+
+                       /* Remove from files list */
+                       for (i = &files; *i; i = &(*i)->next) {
+                               if (*i == tdb->file) {
+                                       *i = tdb->file->next;
+                                       break;
+                               }
                        }
+                       free(tdb->file->lockrecs);
+                       free(tdb->file);
                }
-               free(tdb->file->lockrecs);
-               free(tdb->file);
        }
 
 #ifdef TDB_TRACE