tdb2: add TDB_RDONLY flag, allow setting/unsetting it.

[ccan] / ccan / tdb2 / io.c

diff --git a/ccan/tdb2/io.c b/ccan/tdb2/io.c
index 4166cd4c67caf0475684fc03a0e9de86e714500e..24c70084e9719a513cafae66be5ed30d3c7dcbf6 100644 (file)
--- a/ccan/tdb2/io.c
+++ b/ccan/tdb2/io.c
@@ -42,16 +42,23 @@ void tdb_munmap(struct tdb_file *file)
 
 void tdb_mmap(struct tdb_context *tdb)
 {
+       int mmap_flags;
+
        if (tdb->flags & TDB_INTERNAL)
                return;
 
        if (tdb->flags & TDB_NOMMAP)
                return;
 
+       if ((tdb->open_flags & O_ACCMODE) == O_RDONLY)
+               mmap_flags = PROT_READ;
+       else
+               mmap_flags = PROT_READ | PROT_WRITE;
+
        /* size_t can be smaller than off_t. */
        if ((size_t)tdb->file->map_size == tdb->file->map_size) {
                tdb->file->map_ptr = mmap(NULL, tdb->file->map_size,
-                                         tdb->mmap_flags,
+                                         mmap_flags,
                                          MAP_SHARED, tdb->file->fd, 0);
        } else
                tdb->file->map_ptr = MAP_FAILED;
@@ -193,7 +200,7 @@ enum TDB_ERROR zero_out(struct tdb_context *tdb, tdb_off_t off, tdb_len_t len)
        void *p = tdb->methods->direct(tdb, off, len, true);
        enum TDB_ERROR ecode = TDB_SUCCESS;
 
-       assert(!tdb->read_only);
+       assert(!(tdb->flags & TDB_RDONLY));
        if (TDB_PTR_IS_ERR(p)) {
                return TDB_PTR_ERR(p);
        }
@@ -241,7 +248,7 @@ static enum TDB_ERROR tdb_write(struct tdb_context *tdb, tdb_off_t off,
 {
        enum TDB_ERROR ecode;
 
-       if (tdb->read_only) {
+       if (tdb->flags & TDB_RDONLY) {
                return tdb_logerr(tdb, TDB_ERR_RDONLY, TDB_LOG_USE_ERROR,
                                  "Write to read-only database");
        }
@@ -330,7 +337,7 @@ enum TDB_ERROR tdb_read_convert(struct tdb_context *tdb, tdb_off_t off,
 enum TDB_ERROR tdb_write_off(struct tdb_context *tdb,
                             tdb_off_t off, tdb_off_t val)
 {
-       if (tdb->read_only) {
+       if (tdb->flags & TDB_RDONLY) {
                return tdb_logerr(tdb, TDB_ERR_RDONLY, TDB_LOG_USE_ERROR,
                                  "Write to read-only database");
        }
@@ -409,7 +416,7 @@ static enum TDB_ERROR tdb_expand_file(struct tdb_context *tdb,
        char buf[8192];
        enum TDB_ERROR ecode;
 
-       if (tdb->read_only) {
+       if (tdb->flags & TDB_RDONLY) {
                return tdb_logerr(tdb, TDB_ERR_RDONLY, TDB_LOG_USE_ERROR,
                                  "Expand on read-only database");
        }
@@ -481,7 +488,7 @@ void *tdb_access_write(struct tdb_context *tdb,
 {
        void *ret = NULL;
 
-       if (tdb->read_only) {
+       if (tdb->flags & TDB_RDONLY) {
                tdb_logerr(tdb, TDB_ERR_RDONLY, TDB_LOG_USE_ERROR,
                           "Write to read-only database");
                return TDB_ERR_PTR(TDB_ERR_RDONLY);