Rename real_size to valid_size and add comment about this field.

[android-x86/external-exfat.git] / libexfat / node.c

diff --git a/libexfat/node.c b/libexfat/node.c
index f3207fb..8dd946f 100644 (file)
--- a/libexfat/node.c
+++ b/libexfat/node.c
@@ -194,7 +194,7 @@ static const struct exfat_entry* get_entry_ptr(const struct exfat* ef,
 }
 
 static bool check_node(const struct exfat_node* node, uint16_t actual_checksum,
-               uint16_t reference_checksum, uint64_t real_size)
+               uint16_t reference_checksum, uint64_t valid_size)
 {
        char buffer[UTF8_BYTES(EXFAT_NAME_MAX) + 1];
 
@@ -211,14 +211,16 @@ static bool check_node(const struct exfat_node* node, uint16_t actual_checksum,
        }
 
        /*
-          It's unclear what is real_size field needed for. It usually equals to
-          the size but may contain any value less than size (including 0).
+          exFAT does not support sparse files but allows files with uninitialized
+          clusters. For such files valid_size means initialized data size and
+          cannot be greater than file size. See SetFileValidData() function
+          description in MSDN.
        */
-       if (real_size > node->size)
+       if (valid_size > node->size)
        {
                exfat_get_name(node, buffer, sizeof(buffer) - 1);
-               exfat_error("'%s' has real size (%"PRIu64") greater than size "
-                               "(%"PRIu64")", buffer, real_size, node->size);
+               exfat_error("'%s' has valid size (%"PRIu64") greater than size "
+                               "(%"PRIu64")", buffer, valid_size, node->size);
                return false;
        }
 
@@ -244,7 +246,7 @@ static int readdir(struct exfat* ef, const struct exfat_node* parent,
        le16_t* namep = NULL;
        uint16_t reference_checksum = 0;
        uint16_t actual_checksum = 0;
-       uint64_t real_size = 0;
+       uint64_t valid_size = 0;
 
        *node = NULL;
 
@@ -315,7 +317,7 @@ static int readdir(struct exfat* ef, const struct exfat_node* parent,
                        }
                        init_node_meta2(*node, meta2);
                        actual_checksum = exfat_add_checksum(entry, actual_checksum);
-                       real_size = le64_to_cpu(meta2->real_size);
+                       valid_size = le64_to_cpu(meta2->valid_size);
                        /* empty files must be marked as non-contiguous */
                        if ((*node)->size == 0 && (meta2->flags & EXFAT_FLAG_CONTIGUOUS))
                        {
@@ -351,7 +353,7 @@ static int readdir(struct exfat* ef, const struct exfat_node* parent,
                        if (--continuations == 0)
                        {
                                if (!check_node(*node, actual_checksum, reference_checksum,
-                                               real_size))
+                                               valid_size))
                                        goto error;
                                if (fetch_next_entry(ef, parent, it) != 0)
                                        goto error;
@@ -630,7 +632,7 @@ int exfat_flush_node(struct exfat* ef, struct exfat_node* node)
        }
        if (meta2.type != EXFAT_ENTRY_FILE_INFO)
                exfat_bug("invalid type of meta2: 0x%hhx", meta2.type);
-       meta2.size = meta2.real_size = cpu_to_le64(node->size);
+       meta2.size = meta2.valid_size = cpu_to_le64(node->size);
        meta2.start_cluster = cpu_to_le32(node->start_cluster);
        meta2.flags = EXFAT_FLAG_ALWAYS1;
        /* empty files must not be marked as contiguous */