libext2fs: add default_bitmap_type to the ext2_filsys structure

This allows a program to control the bitmap backend implementation
that will get used without needing to change the current library API.

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

diff --git a/lib/ext2fs/bitmaps.c b/lib/ext2fs/bitmaps.c
index e518295..8402191 100644 (file)
--- a/lib/ext2fs/bitmaps.c
+++ b/lib/ext2fs/bitmaps.c
@@ -67,9 +67,9 @@ errcode_t ext2fs_allocate_inode_bitmap(ext2_filsys fs,
        /* Are we permitted to use new-style bitmaps? */
        if (fs->flags & EXT2_FLAG_64BITS)
                return (ext2fs_alloc_generic_bmap(fs,
-                                 EXT2_ET_MAGIC_INODE_BITMAP64,
-                                 EXT2FS_BMAP64_BITARRAY,
-                                 start, end, real_end, descr, ret));
+                               EXT2_ET_MAGIC_INODE_BITMAP64,
+                               fs->default_bitmap_type,
+                               start, end, real_end, descr, ret));
 
        /* Otherwise, check to see if the file system is small enough
         * to use old-style 32-bit bitmaps */
@@ -99,9 +99,9 @@ errcode_t ext2fs_allocate_block_bitmap(ext2_filsys fs,
 
        if (fs->flags & EXT2_FLAG_64BITS)
                return (ext2fs_alloc_generic_bmap(fs,
-                                 EXT2_ET_MAGIC_BLOCK_BITMAP64,
-                                 EXT2FS_BMAP64_BITARRAY,
-                                 start, end, real_end, descr, ret));
+                               EXT2_ET_MAGIC_BLOCK_BITMAP64,
+                               fs->default_bitmap_type,
+                               start, end, real_end, descr, ret));
 
        if ((end > ~0U) || (real_end > ~0U))
                return EXT2_ET_CANT_USE_LEGACY_BITMAPS;
@@ -143,7 +143,7 @@ errcode_t ext2fs_allocate_subcluster_bitmap(ext2_filsys fs,
                    * (__u64) fs->group_desc_count)-1 + start;
 
        retval = ext2fs_alloc_generic_bmap(fs, EXT2_ET_MAGIC_BLOCK_BITMAP64,
-                                          EXT2FS_BMAP64_BITARRAY, start,
+                                          fs->default_bitmap_type, start,
                                           end, real_end, descr, &bmap);
        if (retval)
                return retval;

diff --git a/lib/ext2fs/ext2fs.h b/lib/ext2fs/ext2fs.h
index 227ee58..d90a8b1 100644 (file)
--- a/lib/ext2fs/ext2fs.h
+++ b/lib/ext2fs/ext2fs.h
@@ -244,10 +244,12 @@ struct struct_ext2_filsys {
        __u32                           umask;
        time_t                          now;
        int                             cluster_ratio_bits;
+       __u16                           default_bitmap_type;
+       __u16                           pad;
        /*
         * Reserved for future expansion
         */
-       __u32                           reserved[6];
+       __u32                           reserved[5];
 
        /*
         * Reserved for the use of the calling application.
@@ -287,6 +289,12 @@ struct struct_ext2_filsys {
 #endif
 
 /*
+ * 64-bit bitmap backend types
+ */
+
+#define EXT2FS_BMAP64_BITARRAY 1
+
+/*
  * Return flags for the block iterator functions
  */
 #define BLOCK_CHANGED  1

diff --git a/lib/ext2fs/ext2fsP.h b/lib/ext2fs/ext2fsP.h
index 82e1ba0..729d5c5 100644 (file)
--- a/lib/ext2fs/ext2fsP.h
+++ b/lib/ext2fs/ext2fsP.h
@@ -109,8 +109,6 @@ extern void ext2fs_numeric_progress_close(ext2_filsys fs,
  * 64-bit bitmap support
  */
 
-#define EXT2FS_BMAP64_BITARRAY 1
-
 extern errcode_t ext2fs_alloc_generic_bmap(ext2_filsys fs, errcode_t magic,
                                           int type, __u64 start, __u64 end,
                                           __u64 real_end,

diff --git a/lib/ext2fs/gen_bitmap64.c b/lib/ext2fs/gen_bitmap64.c
index 4dc4e08..e1b4f42 100644 (file)
--- a/lib/ext2fs/gen_bitmap64.c
+++ b/lib/ext2fs/gen_bitmap64.c
@@ -88,6 +88,9 @@ errcode_t ext2fs_alloc_generic_bmap(ext2_filsys fs, errcode_t magic,
        struct ext2_bitmap_ops  *ops;
        errcode_t retval;
 
+       if (!type)
+               type = EXT2FS_BMAP64_BITARRAY;
+
        switch (type) {
        case EXT2FS_BMAP64_BITARRAY:
                ops = &ext2fs_blkmap64_bitarray;