X-Git-Url: http://git.ozlabs.org/?p=ccan;a=blobdiff_plain;f=ccan%2Ftdb2%2Fio.c;h=24c70084e9719a513cafae66be5ed30d3c7dcbf6;hp=240a1c038da368c274363cb3cfcd37945a517a0e;hb=fab544c24c1ad6523f95893abcaec4e6cce6c2b4;hpb=8cca0397ef6f6017b13ce9ab4999bf3d92a2dee5

diff --git a/ccan/tdb2/io.c b/ccan/tdb2/io.c
index 240a1c03..24c70084 100644
--- a/ccan/tdb2/io.c
+++ b/ccan/tdb2/io.c
@@ -42,14 +42,26 @@ 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;
 
-	tdb->file->map_ptr = mmap(NULL, tdb->file->map_size, tdb->mmap_flags,
-				  MAP_SHARED, tdb->file->fd, 0);
+	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,
+					  mmap_flags,
+					  MAP_SHARED, tdb->file->fd, 0);
+	} else
+		tdb->file->map_ptr = MAP_FAILED;
 
 	/*
 	 * NB. When mmap fails it returns MAP_FAILED *NOT* NULL !!!!
@@ -65,7 +77,9 @@ void tdb_mmap(struct tdb_context *tdb)
 /* check for an out of bounds access - if it is out of bounds then
    see if the database has been expanded by someone else and expand
    if necessary
-   note that "len" is the minimum length needed for the db
+   note that "len" is the minimum length needed for the db.
+
+   If probe is true, len being too large isn't a failure.
 */
 static enum TDB_ERROR tdb_oob(struct tdb_context *tdb, tdb_off_t len,
 			      bool probe)
@@ -79,15 +93,16 @@ static enum TDB_ERROR tdb_oob(struct tdb_context *tdb, tdb_off_t len,
 	       || tdb_has_expansion_lock(tdb));
 
 	if (len <= tdb->file->map_size)
-		return 0;
+		return TDB_SUCCESS;
 	if (tdb->flags & TDB_INTERNAL) {
-		if (!probe) {
-			tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
-				 "tdb_oob len %lld beyond internal"
-				 " malloc size %lld",
-				 (long long)len,
-				 (long long)tdb->file->map_size);
-		}
+		if (probe)
+			return TDB_SUCCESS;
+
+		tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
+			   "tdb_oob len %lld beyond internal"
+			   " malloc size %lld",
+			   (long long)len,
+			   (long long)tdb->file->map_size);
 		return TDB_ERR_IO;
 	}
 
@@ -106,11 +121,12 @@ static enum TDB_ERROR tdb_oob(struct tdb_context *tdb, tdb_off_t len,
 	tdb_unlock_expand(tdb, F_RDLCK);
 
 	if (st.st_size < (size_t)len) {
-		if (!probe) {
-			tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
-				   "tdb_oob len %zu beyond eof at %zu",
-				   (size_t)len, st.st_size);
-		}
+		if (probe)
+			return TDB_SUCCESS;
+
+		tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
+			   "tdb_oob len %zu beyond eof at %zu",
+			   (size_t)len, st.st_size);
 		return TDB_ERR_IO;
 	}
 
@@ -125,6 +141,7 @@ static enum TDB_ERROR tdb_oob(struct tdb_context *tdb, tdb_off_t len,
 /* Endian conversion: we only ever deal with 8 byte quantities */
 void *tdb_convert(const struct tdb_context *tdb, void *buf, tdb_len_t size)
 {
+	assert(size % 8 == 0);
 	if (unlikely((tdb->flags & TDB_CONVERT)) && buf) {
 		uint64_t i, *p = (uint64_t *)buf;
 		for (i = 0; i < size / 8; i++)
@@ -183,7 +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);
 	}
@@ -231,12 +248,12 @@ 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");
 	}
 
-	ecode = tdb->methods->oob(tdb, off + len, 0);
+	ecode = tdb->methods->oob(tdb, off + len, false);
 	if (ecode != TDB_SUCCESS) {
 		return ecode;
 	}
@@ -266,7 +283,7 @@ static enum TDB_ERROR tdb_read(struct tdb_context *tdb, tdb_off_t off,
 {
 	enum TDB_ERROR ecode;
 
-	ecode = tdb->methods->oob(tdb, off + len, 0);
+	ecode = tdb->methods->oob(tdb, off + len, false);
 	if (ecode != TDB_SUCCESS) {
 		return ecode;
 	}
@@ -320,7 +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");
 	}
@@ -399,7 +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");
 	}
@@ -471,7 +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);
@@ -557,7 +574,7 @@ static void *tdb_direct(struct tdb_context *tdb, tdb_off_t off, size_t len,
 	if (unlikely(!tdb->file->map_ptr))
 		return NULL;
 
-	ecode = tdb_oob(tdb, off + len, true);
+	ecode = tdb_oob(tdb, off + len, false);
 	if (unlikely(ecode != TDB_SUCCESS))
 		return TDB_ERR_PTR(ecode);
 	return (char *)tdb->file->map_ptr + off;