libext2fs: refactor common code into ext2fs_dx_csum()

ext2fs_dx_csum() is currently a static function, so this has no
visible changes except shrinking the text size of csum.o by
approximately 100 bytes.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/lib/ext2fs/csum.c b/lib/ext2fs/csum.c
index 9823613760a94389028c70e2618fd6f1f1e68bde..bc80939957b0c319add45aa1c5128711d8e83858 100644 (file)
--- a/lib/ext2fs/csum.c
+++ b/lib/ext2fs/csum.c
@@ -360,18 +360,29 @@ static errcode_t ext2fs_dirent_csum_set(ext2_filsys fs, ext2_ino_t inum,
 
 static errcode_t ext2fs_dx_csum(ext2_filsys fs, ext2_ino_t inum,
                                struct ext2_dir_entry *dirent,
-                               __u32 *crc, int count_offset, int count,
-                               struct ext2_dx_tail *t)
+                               __u32 *crc, struct ext2_dx_tail **ret_t)
 {
        errcode_t retval;
        char *buf = (char *)dirent;
        int size;
-       __u32 old_csum, gen;
+       __u32 gen, dummy_csum = 0;
        struct ext2_inode inode;
+       struct ext2_dx_tail *t;
+       struct ext2_dx_countlimit *c;
+       int count_offset, limit, count;
+
+       retval = __get_dx_countlimit(fs, dirent, &c, &count_offset, 1);
+       if (retval)
+               return retval;
+       limit = ext2fs_le16_to_cpu(c->limit);
+       count = ext2fs_le16_to_cpu(c->count);
+       if (count_offset + (limit * sizeof(struct ext2_dx_entry)) >
+           fs->blocksize - sizeof(struct ext2_dx_tail))
+               return EXT2_ET_DIR_NO_SPACE_FOR_CSUM;
+       /* htree structs are accessed in LE order */
+       t = (struct ext2_dx_tail *)(((struct ext2_dx_entry *)c) + limit);
 
        size = count_offset + (count * sizeof(struct ext2_dx_entry));
-       old_csum = t->dt_checksum;
-       t->dt_checksum = 0;
 
        retval = ext2fs_read_inode(fs, inum, &inode);
        if (retval)
@@ -383,10 +394,11 @@ static errcode_t ext2fs_dx_csum(ext2_filsys fs, ext2_ino_t inum,
                                sizeof(inum));
        *crc = ext2fs_crc32c_le(*crc, (unsigned char *)&gen, sizeof(gen));
        *crc = ext2fs_crc32c_le(*crc, (unsigned char *)buf, size);
-       *crc = ext2fs_crc32c_le(*crc, (unsigned char *)t,
-                               sizeof(struct ext2_dx_tail));
-       t->dt_checksum = old_csum;
+       *crc = ext2fs_crc32c_le(*crc, (unsigned char *)t, 4);
+       *crc = ext2fs_crc32c_le(*crc, (unsigned char *)&dummy_csum, 4);
 
+       if (ret_t)
+               *ret_t = t;
        return 0;
 }
 
@@ -395,22 +407,9 @@ static int ext2fs_dx_csum_verify(ext2_filsys fs, ext2_ino_t inum,
 {
        __u32 calculated;
        errcode_t retval;
-       struct ext2_dx_countlimit *c;
        struct ext2_dx_tail *t;
-       int count_offset, limit, count;
 
-       retval = __get_dx_countlimit(fs, dirent, &c, &count_offset, 1);
-       if (retval)
-               return 1;
-       limit = ext2fs_le16_to_cpu(c->limit);
-       count = ext2fs_le16_to_cpu(c->count);
-       if (count_offset + (limit * sizeof(struct ext2_dx_entry)) >
-           fs->blocksize - sizeof(struct ext2_dx_tail))
-               return 0;
-       /* htree structs are accessed in LE order */
-       t = (struct ext2_dx_tail *)(((struct ext2_dx_entry *)c) + limit);
-       retval = ext2fs_dx_csum(fs, inum, dirent, &calculated, count_offset,
-                               count, t);
+       retval = ext2fs_dx_csum(fs, inum, dirent, &calculated, &t);
        if (retval)
                return 0;
 
@@ -422,22 +421,9 @@ static errcode_t ext2fs_dx_csum_set(ext2_filsys fs, ext2_ino_t inum,
 {
        __u32 crc;
        errcode_t retval = 0;
-       struct ext2_dx_countlimit *c;
        struct ext2_dx_tail *t;
-       int count_offset, limit, count;
 
-       retval = __get_dx_countlimit(fs, dirent, &c, &count_offset, 1);
-       if (retval)
-               return retval;
-       limit = ext2fs_le16_to_cpu(c->limit);
-       count = ext2fs_le16_to_cpu(c->count);
-       if (count_offset + (limit * sizeof(struct ext2_dx_entry)) >
-           fs->blocksize - sizeof(struct ext2_dx_tail))
-               return EXT2_ET_DIR_NO_SPACE_FOR_CSUM;
-       t = (struct ext2_dx_tail *)(((struct ext2_dx_entry *)c) + limit);
-
-       /* htree structs are accessed in LE order */
-       retval = ext2fs_dx_csum(fs, inum, dirent, &crc, count_offset, count, t);
+       retval = ext2fs_dx_csum(fs, inum, dirent, &crc, &t);
        if (retval)
                return retval;
        t->dt_checksum = ext2fs_cpu_to_le32(crc);