[PATCH 09/15][e2fsprogs] Add 64-bit closefs interface.

Jose R. Santos
2008-07-15T16:51:04Z

From: Jose R. Santos <jrs@us.ibm.com>

Add 64-bit closefs interface.

Add new ext2fs_super_and_bgd_loc2() that returns blk64_t pointers.
The function now returns the number of blocks used by super block and
group descriptors since with flex_bg, it can no longer be assumed that
bitmaps and inode tables still resided within the block group.

Signed-off-by: Jose R. Santos <jrs@us.ibm.com>
--

lib/ext2fs/closefs.c | 120 +++++++++++++++++++++++++++++++++++---------------
lib/ext2fs/ext2fs.h | 6 +++
2 files changed, 90 insertions(+), 36 deletions(-)
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
--

lib/ext2fs/closefs.c | 120 +++++++++++++++++++++++++++++++++++---------------
lib/ext2fs/ext2fs.h | 6 +++
2 files changed, 90 insertions(+), 36 deletions(-)

diff --git a/lib/ext2fs/closefs.c b/lib/ext2fs/closefs.c
index 206faa6..8231ca6 100644
--- a/lib/ext2fs/closefs.c
+++ b/lib/ext2fs/closefs.c
@@ -46,31 +46,33 @@ int ext2fs_bg_has_super(ext2_filsys fs, int group_block)
}

/*
- * This function returns the location of the superblock, block group
- * descriptors for a given block group. It currently returns the
- * number of free blocks assuming that inode table and allocation
- * bitmaps will be in the group. This is not necessarily the case
- * when the flex_bg feature is enabled, so callers should take care!
- * It was only really intended for use by mke2fs, and even there it's
- * not that useful. In the future, when we redo this function for
- * 64-bit block numbers, we should probably return the number of
- * blocks used by the super block and group descriptors instead.
+ * ext2fs_super_and_bgd_loc2()
+ * @fs: ext2 fs pointer
+ * @group given block group
+ * @ret_super_blk: if !NULL, returns super block location
+ * @ret_old_desc_blk: if !NULL, returns location of the old block
+ * group descriptor
+ * @ret_new_desc_blk: if !NULL, returns location of meta_bg block
+ * group descriptor
+ * @ret_used_blks: if !NULL, returns number of blocks used by
+ * super block and group_descriptors.
*
- * See also the comment for ext2fs_reserve_super_and_bgd()
+ * Returns errcode_t of 0
*/
-int ext2fs_super_and_bgd_loc(ext2_filsys fs,
- dgrp_t group,
- blk_t *ret_super_blk,
- blk_t *ret_old_desc_blk,
- blk_t *ret_new_desc_blk,
- int *ret_meta_bg)
+errcode_t ext2fs_super_and_bgd_loc2(ext2_filsys fs,
+ dgrp_t group,
+ blk64_t *ret_super_blk,
+ blk64_t *ret_old_desc_blk,
+ blk64_t *ret_new_desc_blk,
+ blk_t *ret_used_blks)
{
- blk_t group_block, super_blk = 0, old_desc_blk = 0, new_desc_blk = 0;
+ blk64_t group_block, super_blk = 0, old_desc_blk = 0, new_desc_blk = 0;
unsigned int meta_bg, meta_bg_size;
- blk_t numblocks, old_desc_blocks;
+ blk_t numblocks = 0;
+ blk64_t old_desc_blocks;
int has_super;

- group_block = ext2fs_group_first_block(fs, group);
+ group_block = ext2fs_group_first_block2(fs, group);

if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG)
old_desc_blocks = fs->super->s_first_meta_bg;
@@ -78,20 +80,11 @@ int ext2fs_super_and_bgd_loc(ext2_filsys fs,
old_desc_blocks =
fs->desc_blocks + fs->super->s_reserved_gdt_blocks;

- if (group == fs->group_desc_count-1) {
- numblocks = (fs->super->s_blocks_count -
- fs->super->s_first_data_block) %
- fs->super->s_blocks_per_group;
- if (!numblocks)
- numblocks = fs->super->s_blocks_per_group;
- } else
- numblocks = fs->super->s_blocks_per_group;
-
has_super = ext2fs_bg_has_super(fs, group);

if (has_super) {
super_blk = group_block;
- numblocks--;
+ numblocks++;
}
meta_bg_size = EXT2_DESC_PER_BLOCK(fs->super);
meta_bg = group / meta_bg_size;
@@ -100,7 +93,7 @@ int ext2fs_super_and_bgd_loc(ext2_filsys fs,
(meta_bg < fs->super->s_first_meta_bg)) {
if (has_super) {
old_desc_blk = group_block + 1;
- numblocks -= old_desc_blocks;
+ numblocks += old_desc_blocks;
}
} else {
if (((group % meta_bg_size) == 0) ||
@@ -109,11 +102,9 @@ int ext2fs_super_and_bgd_loc(ext2_filsys fs,
if (has_super)
has_super = 1;
new_desc_blk = group_block + has_super;
- numblocks--;
+ numblocks++;
}
}
-
- numblocks -= 2 + fs->inode_blocks_per_group;

if (ret_super_blk)
*ret_super_blk = super_blk;
@@ -121,11 +112,68 @@ int ext2fs_super_and_bgd_loc(ext2_filsys fs,
*ret_old_desc_blk = old_desc_blk;
if (ret_new_desc_blk)
*ret_new_desc_blk = new_desc_blk;
- if (ret_meta_bg)
- *ret_meta_bg = meta_bg;
- return (numblocks);
+ if (ret_used_blks)
+ *ret_used_blks = numblocks;
+
+ return 0;
}

+/*
+ * This function returns the location of the superblock, block group
+ * descriptors for a given block group. It currently returns the
+ * number of free blocks assuming that inode table and allocation
+ * bitmaps will be in the group. This is not necessarily the case
+ * when the flex_bg feature is enabled, so callers should take care!
+ * It was only really intended for use by mke2fs, and even there it's
+ * not that useful.
+ *
+ * The ext2fs_super_and_bgd_loc2() function is 64-bit block number
+ * capable and returns the number of blocks used by super block and
+ * group descriptors.
+ */
+int ext2fs_super_and_bgd_loc(ext2_filsys fs,
+ dgrp_t group,
+ blk_t *ret_super_blk,
+ blk_t *ret_old_desc_blk,
+ blk_t *ret_new_desc_blk,
+ int *ret_meta_bg)
+{
+ blk64_t ret_super_blk2;
+ blk64_t ret_old_desc_blk2;
+ blk64_t ret_new_desc_blk2;
+ blk_t ret_used_blks;
+ blk_t numblocks;
+ unsigned int meta_bg_size;
+
+ ext2fs_super_and_bgd_loc2(fs, group, &ret_super_blk2,
+ &ret_old_desc_blk2,
+ &ret_new_desc_blk2,
+ &ret_used_blks);
+
+ if (group == fs->group_desc_count-1) {
+ numblocks = (fs->super->s_blocks_count -
+ fs->super->s_first_data_block) %
+ fs->super->s_blocks_per_group;
+ if (!numblocks)
+ numblocks = fs->super->s_blocks_per_group;
+ } else
+ numblocks = fs->super->s_blocks_per_group;
+
+ if (ret_super_blk)
+ *ret_super_blk = (blk_t)ret_super_blk2;
+ if (ret_old_desc_blk)
+ *ret_old_desc_blk = (blk_t)ret_old_desc_blk2;
+ if (ret_new_desc_blk)
+ *ret_new_desc_blk = (blk_t)ret_new_desc_blk2;
+ if (ret_meta_bg) {
+ meta_bg_size = EXT2_DESC_PER_BLOCK(fs->super);
+ *ret_meta_bg = group / meta_bg_size;
+ }
+
+ numblocks -= 2 + fs->inode_blocks_per_group + ret_used_blks;
+
+ return numblocks;
+}

/*
* This function forces out the primary superblock. We need to only
diff --git a/lib/ext2fs/ext2fs.h b/lib/ext2fs/ext2fs.h
index d576181..464d323 100644
--- a/lib/ext2fs/ext2fs.h
+++ b/lib/ext2fs/ext2fs.h
@@ -763,6 +763,12 @@ extern errcode_t ext2fs_check_desc(ext2_filsys fs);
extern errcode_t ext2fs_close(ext2_filsys fs);
extern errcode_t ext2fs_flush(ext2_filsys fs);
extern int ext2fs_bg_has_super(ext2_filsys fs, int group_block);
+extern errcode_t ext2fs_super_and_bgd_loc2(ext2_filsys fs,
+ dgrp_t group,
+ blk64_t *ret_super_blk,
+ blk64_t *ret_old_desc_blk,
+ blk64_t *ret_new_desc_blk,
+ blk_t *ret_used_blks);
extern int ext2fs_super_and_bgd_loc(ext2_filsys fs,
dgrp_t group,
blk_t *ret_super_blk,