libext2fs: Add callback functions for _alloc_block() and _block_alloc_stats()

Add callback functions for ext2fs_alloc_block() and
ext2fs_block_alloc_stats().  This is needed so e2fsck can be informed
when the extent_set_bmap() function needs to allocate or deallocate
blocks.

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

diff --git a/lib/ext2fs/alloc.c b/lib/ext2fs/alloc.c
index 65f3ea1c3a135511290e4199e45d24964be6a11b..f8d8a5fbb289b562412d2ec61c3b5621e3d509cf 100644 (file)
--- a/lib/ext2fs/alloc.c
+++ b/lib/ext2fs/alloc.c
@@ -118,15 +118,24 @@ errcode_t ext2fs_alloc_block(ext2_filsys fs, blk_t goal,
        }
        memset(block_buf, 0, fs->blocksize);
 
-       if (!fs->block_map) {
-               retval = ext2fs_read_block_bitmap(fs);
+       if (fs->get_alloc_block) {
+               blk64_t new;
+
+               retval = (fs->get_alloc_block)(fs, (blk64_t) goal, &new);
                if (retval)
                        goto fail;
-       }
+               block = (blk_t) new;
+       } else {
+               if (!fs->block_map) {
+                       retval = ext2fs_read_block_bitmap(fs);
+                       if (retval)
+                               goto fail;
+               }
 
-       retval = ext2fs_new_block(fs, goal, 0, &block);
-       if (retval)
-               goto fail;
+               retval = ext2fs_new_block(fs, goal, 0, &block);
+               if (retval)
+                       goto fail;
+       }
 
        retval = io_channel_write_blk(fs->io, block, 1, block_buf);
        if (retval)
@@ -170,3 +179,19 @@ errcode_t ext2fs_get_free_blocks(ext2_filsys fs, blk_t start, blk_t finish,
        return EXT2_ET_BLOCK_ALLOC_FAIL;
 }
 
+void ext2fs_set_alloc_block_callback(ext2_filsys fs, 
+                                    errcode_t (*func)(ext2_filsys fs,
+                                                      blk64_t goal,
+                                                      blk64_t *ret),
+                                    errcode_t (**old)(ext2_filsys fs,
+                                                      blk64_t goal,
+                                                      blk64_t *ret))
+{
+       if (!fs || fs->magic != EXT2_ET_MAGIC_EXT2FS_FILSYS)
+               return;
+
+       if (old)
+               *old = fs->get_alloc_block;
+
+       fs->get_alloc_block = func;
+}

diff --git a/lib/ext2fs/alloc_stats.c b/lib/ext2fs/alloc_stats.c
index 3956528f9992f0996c515f54840f5048ae3f83d4..a8514cc2efdefeb56188e4e43486dc793be15304 100644 (file)
--- a/lib/ext2fs/alloc_stats.c
+++ b/lib/ext2fs/alloc_stats.c
@@ -69,4 +69,22 @@ void ext2fs_block_alloc_stats(ext2_filsys fs, blk_t blk, int inuse)
        fs->super->s_free_blocks_count -= inuse;
        ext2fs_mark_super_dirty(fs);
        ext2fs_mark_bb_dirty(fs);
+       if (fs->block_alloc_stats)
+               (fs->block_alloc_stats)(fs, (blk64_t) blk, inuse);
+}
+
+void ext2fs_set_block_alloc_stats_callback(ext2_filsys fs, 
+                                          void (*func)(ext2_filsys fs,
+                                                       blk64_t blk,
+                                                       int inuse),
+                                          void (**old)(ext2_filsys fs,
+                                                       blk64_t blk,
+                                                       int inuse))
+{
+       if (!fs || fs->magic != EXT2_ET_MAGIC_EXT2FS_FILSYS)
+               return;
+       if (old)
+               *old = fs->block_alloc_stats;
+
+       fs->block_alloc_stats = func;
 }

diff --git a/lib/ext2fs/ext2fs.h b/lib/ext2fs/ext2fs.h
index 3ef3b0dc2c23819cdbe27e0f49c2ae4e2e69a97e..ebad54e6a79e144fd6dbc2c0a636f68f66c40cac 100644 (file)
--- a/lib/ext2fs/ext2fs.h
+++ b/lib/ext2fs/ext2fs.h
@@ -229,6 +229,13 @@ struct struct_ext2_filsys {
         */
        struct ext2_inode_cache         *icache;
        io_channel                      image_io;
+
+       /*
+        * More callback functions
+        */
+       errcode_t (*get_alloc_block)(ext2_filsys fs, blk64_t goal,
+                                    blk64_t *ret);
+       void (*block_alloc_stats)(ext2_filsys fs, blk64_t blk, int inuse);
 };
 
 #if EXT2_FLAT_INCLUDES
@@ -552,11 +559,25 @@ extern errcode_t ext2fs_get_free_blocks(ext2_filsys fs, blk_t start,
                                        blk_t *ret);
 extern errcode_t ext2fs_alloc_block(ext2_filsys fs, blk_t goal,
                                    char *block_buf, blk_t *ret);
+extern void ext2fs_set_alloc_block_callback(ext2_filsys fs, 
+                                           errcode_t (*func)(ext2_filsys fs,
+                                                             blk64_t goal,
+                                                             blk64_t *ret),
+                                           errcode_t (**old)(ext2_filsys fs,
+                                                             blk64_t goal,
+                                                             blk64_t *ret));
 
 /* alloc_sb.c */
 extern int ext2fs_reserve_super_and_bgd(ext2_filsys fs, 
                                        dgrp_t group,
                                        ext2fs_block_bitmap bmap);
+extern void ext2fs_set_block_alloc_stats_callback(ext2_filsys fs, 
+                                                 void (*func)(ext2_filsys fs,
+                                                              blk64_t blk,
+                                                              int inuse),
+                                                 void (**old)(ext2_filsys fs,
+                                                              blk64_t blk,
+                                                              int inuse));
 
 /* alloc_stats.c */
 void ext2fs_inode_alloc_stats(ext2_filsys fs, ext2_ino_t ino, int inuse);