tdb: add proper OOM/ENOSPC handling to tdb_expand()
[obnox/samba/samba-obnox.git] / lib / tdb / common / io.c
index 7e29c38440fb11e49a890f60c36668e7cc224991..87d47b970b0a239117c9d20903d8929837c7668a 100644 (file)
@@ -40,8 +40,8 @@ static int tdb_oob(struct tdb_context *tdb, tdb_off_t off, tdb_len_t len,
                if (!probe) {
                        /* Ensure ecode is set for log fn. */
                        tdb->ecode = TDB_ERR_IO;
-                       TDB_LOG((tdb, TDB_DEBUG_FATAL,"tdb_oob off %d len %d wrap\n",
-                                (int)off, (int)len));
+                       TDB_LOG((tdb, TDB_DEBUG_FATAL,"tdb_oob off %u len %u wrap\n",
+                                off, len));
                }
                return -1;
        }
@@ -127,8 +127,8 @@ static int tdb_write(struct tdb_context *tdb, tdb_off_t off,
                        /* try once more */
                        tdb->ecode = TDB_ERR_IO;
                        TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_write: wrote only "
-                                "%d of %d bytes at %d, trying once more\n",
-                                (int)written, len, off));
+                                "%zi of %u bytes at %u, trying once more\n",
+                                written, len, off));
                        written = pwrite(tdb->fd, (const char *)buf+written,
                                         len-written,
                                         off+written);
@@ -136,13 +136,13 @@ static int tdb_write(struct tdb_context *tdb, tdb_off_t off,
                if (written == -1) {
                        /* Ensure ecode is set for log fn. */
                        tdb->ecode = TDB_ERR_IO;
-                       TDB_LOG((tdb, TDB_DEBUG_FATAL,"tdb_write failed at %d "
-                                "len=%d (%s)\n", off, len, strerror(errno)));
+                       TDB_LOG((tdb, TDB_DEBUG_FATAL,"tdb_write failed at %u "
+                                "len=%u (%s)\n", off, len, strerror(errno)));
                        return -1;
                } else if (written != (ssize_t)len) {
                        tdb->ecode = TDB_ERR_IO;
                        TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_write: failed to "
-                                "write %d bytes at %d in two attempts\n",
+                                "write %u bytes at %u in two attempts\n",
                                 len, off));
                        return -1;
                }
@@ -180,10 +180,10 @@ static int tdb_read(struct tdb_context *tdb, tdb_off_t off, void *buf,
                if (ret != (ssize_t)len) {
                        /* Ensure ecode is set for log fn. */
                        tdb->ecode = TDB_ERR_IO;
-                       TDB_LOG((tdb, TDB_DEBUG_FATAL,"tdb_read failed at %d "
-                                "len=%d ret=%d (%s) map_size=%d\n",
-                                (int)off, (int)len, (int)ret, strerror(errno),
-                                (int)tdb->map_size));
+                       TDB_LOG((tdb, TDB_DEBUG_FATAL,"tdb_read failed at %u "
+                                "len=%u ret=%zi (%s) map_size=%u\n",
+                                off, len, ret, strerror(errno),
+                                tdb->map_size));
                        return -1;
                }
 #endif
@@ -266,7 +266,7 @@ int tdb_mmap(struct tdb_context *tdb)
 
                if (tdb->map_ptr == MAP_FAILED) {
                        tdb->map_ptr = NULL;
-                       TDB_LOG((tdb, TDB_DEBUG_WARNING, "tdb_mmap failed for size %d (%s)\n",
+                       TDB_LOG((tdb, TDB_DEBUG_WARNING, "tdb_mmap failed for size %u (%s)\n",
                                 tdb->map_size, strerror(errno)));
 #ifdef HAVE_INCOHERENT_MMAP
                        tdb->ecode = TDB_ERR_IO;
@@ -287,26 +287,37 @@ int tdb_mmap(struct tdb_context *tdb)
 static int tdb_expand_file(struct tdb_context *tdb, tdb_off_t size, tdb_off_t addition)
 {
        char buf[8192];
+       tdb_off_t new_size;
 
        if (tdb->read_only || tdb->traverse_read) {
                tdb->ecode = TDB_ERR_RDONLY;
                return -1;
        }
 
-       if (ftruncate(tdb->fd, size+addition) == -1) {
+       if (!tdb_add_off_t(size, addition, &new_size)) {
+               tdb->ecode = TDB_ERR_OOM;
+               TDB_LOG((tdb, TDB_DEBUG_FATAL, "expand_file write "
+                       "overflow detected current size[%u] addition[%u]!\n",
+                       (unsigned)size, (unsigned)addition));
+               errno = ENOSPC;
+               return -1;
+       }
+
+       if (ftruncate(tdb->fd, new_size) == -1) {
                char b = 0;
-               ssize_t written = pwrite(tdb->fd,  &b, 1, (size+addition) - 1);
+               ssize_t written = pwrite(tdb->fd,  &b, 1, new_size - 1);
                if (written == 0) {
                        /* try once more, potentially revealing errno */
-                       written = pwrite(tdb->fd,  &b, 1, (size+addition) - 1);
+                       written = pwrite(tdb->fd,  &b, 1, new_size - 1);
                }
                if (written == 0) {
                        /* again - give up, guessing errno */
                        errno = ENOSPC;
                }
                if (written != 1) {
-                       TDB_LOG((tdb, TDB_DEBUG_FATAL, "expand_file to %d failed (%s)\n",
-                                size+addition, strerror(errno)));
+                       tdb->ecode = TDB_ERR_OOM;
+                       TDB_LOG((tdb, TDB_DEBUG_FATAL, "expand_file to %u failed (%s)\n",
+                                (unsigned)new_size, strerror(errno)));
                        return -1;
                }
        }
@@ -324,21 +335,23 @@ static int tdb_expand_file(struct tdb_context *tdb, tdb_off_t size, tdb_off_t ad
                }
                if (written == 0) {
                        /* give up, trying to provide a useful errno */
+                       tdb->ecode = TDB_ERR_OOM;
                        TDB_LOG((tdb, TDB_DEBUG_FATAL, "expand_file write "
                                "returned 0 twice: giving up!\n"));
                        errno = ENOSPC;
                        return -1;
                }
                if (written == -1) {
+                       tdb->ecode = TDB_ERR_OOM;
                        TDB_LOG((tdb, TDB_DEBUG_FATAL, "expand_file write of "
-                                "%d bytes failed (%s)\n", (int)n,
+                                "%u bytes failed (%s)\n", (int)n,
                                 strerror(errno)));
                        return -1;
                }
                if (written != n) {
                        TDB_LOG((tdb, TDB_DEBUG_WARNING, "expand_file: wrote "
-                                "only %d of %d bytes - retrying\n", (int)written,
-                                (int)n));
+                                "only %zu of %zi bytes - retrying\n", written,
+                                n));
                }
                addition -= written;
                size += written;
@@ -350,14 +363,32 @@ static int tdb_expand_file(struct tdb_context *tdb, tdb_off_t size, tdb_off_t ad
 /* You need 'size', this tells you how much you should expand by. */
 tdb_off_t tdb_expand_adjust(tdb_off_t map_size, tdb_off_t size, int page_size)
 {
-       tdb_off_t new_size, top_size;
+       tdb_off_t new_size, top_size, increment;
+       tdb_off_t max_size = UINT32_MAX - map_size;
+
+       if (size > max_size) {
+               /*
+                * We can't round up anymore, just give back
+                * what we're asked for.
+                *
+                * The caller has to take care of the ENOSPC handling.
+                */
+               return size;
+       }
 
        /* limit size in order to avoid using up huge amounts of memory for
         * in memory tdbs if an oddball huge record creeps in */
        if (size > 100 * 1024) {
-               top_size = map_size + size * 2;
+               increment = size * 2;
        } else {
-               top_size = map_size + size * 100;
+               increment = size * 100;
+       }
+       if (increment < size) {
+               goto overflow;
+       }
+
+       if (!tdb_add_off_t(map_size, increment, &top_size)) {
+               goto overflow;
        }
 
        /* always make room for at least top_size more records, and at
@@ -368,10 +399,20 @@ tdb_off_t tdb_expand_adjust(tdb_off_t map_size, tdb_off_t size, int page_size)
        } else {
                new_size = map_size * 1.25;
        }
+       if (new_size < map_size) {
+               goto overflow;
+       }
 
        /* Round the database up to a multiple of the page size */
        new_size = MAX(top_size, new_size);
        return TDB_ALIGN(new_size, page_size) - map_size;
+
+overflow:
+       /*
+        * Somewhere in between we went over 4GB. Make one big jump to
+        * exactly 4GB database size.
+        */
+       return max_size;
 }
 
 /* expand the database at least size bytes by expanding the underlying
@@ -380,6 +421,7 @@ int tdb_expand(struct tdb_context *tdb, tdb_off_t size)
 {
        struct tdb_record rec;
        tdb_off_t offset;
+       tdb_off_t new_size;
 
        if (tdb_lock(tdb, -1, F_WRLCK) == -1) {
                TDB_LOG((tdb, TDB_DEBUG_ERROR, "lock failed in tdb_expand\n"));
@@ -391,10 +433,12 @@ int tdb_expand(struct tdb_context *tdb, tdb_off_t size)
 
        size = tdb_expand_adjust(tdb->map_size, size, tdb->page_size);
 
-       /* expand the file itself */
-       if (!(tdb->flags & TDB_INTERNAL)) {
-               if (tdb->methods->tdb_expand_file(tdb, tdb->map_size, size) != 0)
-                       goto fail;
+       if (!tdb_add_off_t(tdb->map_size, size, &new_size)) {
+               tdb->ecode = TDB_ERR_OOM;
+               TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_expand "
+                       "overflow detected current map_size[%u] size[%u]!\n",
+                       (unsigned)tdb->map_size, (unsigned)size));
+               goto fail;
        }
 
        /* form a new freelist record */
@@ -403,18 +447,30 @@ int tdb_expand(struct tdb_context *tdb, tdb_off_t size)
        rec.rec_len = size - sizeof(rec);
 
        if (tdb->flags & TDB_INTERNAL) {
-               char *new_map_ptr = (char *)realloc(tdb->map_ptr,
-                                                   tdb->map_size + size);
+               char *new_map_ptr;
+
+               new_map_ptr = (char *)realloc(tdb->map_ptr, new_size);
                if (!new_map_ptr) {
+                       tdb->ecode = TDB_ERR_OOM;
                        goto fail;
                }
                tdb->map_ptr = new_map_ptr;
-               tdb->map_size += size;
+               tdb->map_size = new_size;
        } else {
+               int ret;
+
+               /*
+                * expand the file itself
+                */
+               ret = tdb->methods->tdb_expand_file(tdb, tdb->map_size, size);
+               if (ret != 0) {
+                       goto fail;
+               }
+
                /* Explicitly remap: if we're in a transaction, this won't
                 * happen automatically! */
                tdb_munmap(tdb);
-               tdb->map_size += size;
+               tdb->map_size = new_size;
                if (tdb_mmap(tdb) != 0) {
                        goto fail;
                }
@@ -454,7 +510,7 @@ unsigned char *tdb_alloc_read(struct tdb_context *tdb, tdb_off_t offset, tdb_len
        if (!(buf = (unsigned char *)malloc(len ? len : 1))) {
                /* Ensure ecode is set for log fn. */
                tdb->ecode = TDB_ERR_OOM;
-               TDB_LOG((tdb, TDB_DEBUG_ERROR,"tdb_alloc_read malloc failed len=%d (%s)\n",
+               TDB_LOG((tdb, TDB_DEBUG_ERROR,"tdb_alloc_read malloc failed len=%u (%s)\n",
                           len, strerror(errno)));
                return NULL;
        }
@@ -507,7 +563,7 @@ int tdb_rec_read(struct tdb_context *tdb, tdb_off_t offset, struct tdb_record *r
        if (TDB_BAD_MAGIC(rec)) {
                /* Ensure ecode is set for log fn. */
                tdb->ecode = TDB_ERR_CORRUPT;
-               TDB_LOG((tdb, TDB_DEBUG_FATAL,"tdb_rec_read bad magic 0x%x at offset=%d\n", rec->magic, offset));
+               TDB_LOG((tdb, TDB_DEBUG_FATAL,"tdb_rec_read bad magic 0x%x at offset=%u\n", rec->magic, offset));
                return -1;
        }
        return tdb->methods->tdb_oob(tdb, rec->next, sizeof(*rec), 0);