[Ocfs2-devel] [PATCH 01/17] ocfs2: Define data structures for discontiguous block groups.
Tao Ma
tao.ma at oracle.com
Wed Apr 21 23:40:15 PDT 2010
From: Joel Becker <joel.becker at oracle.com>
Defines the OCFS2_FEATURE_INCOMPAT_DISCONTIG_BG feature bit and modifies
struct ocfs2_group_desc for the feature.
Signed-off-by: Joel Becker <joel.becker at oracle.com>
Signed-off-by: Tao Ma <tao.ma at oracle.com>
---
fs/ocfs2/localalloc.c | 2 +-
fs/ocfs2/ocfs2_fs.h | 53 ++++++++++++++++++++++++++++++++++++++++++------
fs/ocfs2/resize.c | 4 +-
fs/ocfs2/suballoc.c | 2 +-
fs/ocfs2/super.c | 2 +-
5 files changed, 51 insertions(+), 12 deletions(-)
diff --git a/fs/ocfs2/localalloc.c b/fs/ocfs2/localalloc.c
index 2882f79..cb06315 100644
--- a/fs/ocfs2/localalloc.c
+++ b/fs/ocfs2/localalloc.c
@@ -122,7 +122,7 @@ unsigned int ocfs2_la_default_mb(struct ocfs2_super *osb)
struct super_block *sb = osb->sb;
gd_mb = ocfs2_clusters_to_megabytes(osb->sb,
- 8 * ocfs2_group_bitmap_size(sb));
+ 8 * ocfs2_group_bitmap_size(sb, 0));
/*
* This takes care of files systems with very small group
diff --git a/fs/ocfs2/ocfs2_fs.h b/fs/ocfs2/ocfs2_fs.h
index d61a152..448aa8d 100644
--- a/fs/ocfs2/ocfs2_fs.h
+++ b/fs/ocfs2/ocfs2_fs.h
@@ -165,6 +165,9 @@
/* Refcount tree support */
#define OCFS2_FEATURE_INCOMPAT_REFCOUNT_TREE 0x1000
+/* Discontigous block groups */
+#define OCFS2_FEATURE_INCOMPAT_DISCONTIG_BG 0x2000
+
/*
* backup superblock flag is used to indicate that this volume
* has backup superblocks.
@@ -832,6 +835,13 @@ struct ocfs2_dx_leaf {
};
/*
+ * Largest bitmap for a block (suballocator) group in bytes. This limit
+ * does not affect cluster groups (global allocator). Cluster group
+ * bitmaps run to the end of the block.
+ */
+#define OCFS2_MAX_BG_BITMAP_SIZE 256
+
+/*
* On disk allocator group structure for OCFS2
*/
struct ocfs2_group_desc
@@ -852,7 +862,29 @@ struct ocfs2_group_desc
__le64 bg_blkno; /* Offset on disk, in blocks */
/*30*/ struct ocfs2_block_check bg_check; /* Error checking */
__le64 bg_reserved2;
-/*40*/ __u8 bg_bitmap[0];
+/*40*/ union {
+ __u8 bg_bitmap[0];
+ struct {
+ /*
+ * Block groups may be discontiguous when
+ * OCFS2_FEATURE_INCOMPAT_DISCONTIG_BG is set.
+ * The extents of a discontigous block group are
+ * stored in bg_list. It is a flat list.
+ * l_tree_depth must always be zero. A
+ * discontiguous group is signified by a non-zero
+ * bg_list->l_next_free_rec. Only block groups
+ * can be discontiguous; Cluster groups cannot.
+ * We've never made a block group with more than
+ * 2048 blocks (256 bytes of bg_bitmap). This
+ * codifies that limit so that we can fit bg_list.
+ * bg_size of a discontiguous block group will
+ * be 256 to match bg_bitmap_filler.
+ */
+ __u8 bg_bitmap_filler[OCFS2_MAX_BG_BITMAP_SIZE];
+/*140*/ struct ocfs2_extent_list bg_list;
+ };
+ };
+/* Actual on-disk size is one block */
};
struct ocfs2_refcount_rec {
@@ -1276,12 +1308,16 @@ static inline u16 ocfs2_local_alloc_size(struct super_block *sb)
return size;
}
-static inline int ocfs2_group_bitmap_size(struct super_block *sb)
+static inline int ocfs2_group_bitmap_size(struct super_block *sb,
+ int suballocator)
{
int size;
- size = sb->s_blocksize -
- offsetof(struct ocfs2_group_desc, bg_bitmap);
+ if (suballocator)
+ size = OCFS2_MAX_BG_BITMAP_SIZE;
+ else
+ size = sb->s_blocksize -
+ offsetof(struct ocfs2_group_desc, bg_bitmap);
return size;
}
@@ -1404,12 +1440,15 @@ static inline int ocfs2_local_alloc_size(int blocksize)
return size;
}
-static inline int ocfs2_group_bitmap_size(int blocksize)
+static inline int ocfs2_group_bitmap_size(int blocksize, int suballocator)
{
int size;
- size = blocksize -
- offsetof(struct ocfs2_group_desc, bg_bitmap);
+ if (suballocator)
+ size = OCFS2_MAX_BG_BITMAP_SIZE;
+ else
+ size = blocksize -
+ offsetof(struct ocfs2_group_desc, bg_bitmap);
return size;
}
diff --git a/fs/ocfs2/resize.c b/fs/ocfs2/resize.c
index a821f66..5bbfc12 100644
--- a/fs/ocfs2/resize.c
+++ b/fs/ocfs2/resize.c
@@ -315,7 +315,7 @@ int ocfs2_group_extend(struct inode * inode, int new_clusters)
BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
if (le16_to_cpu(fe->id2.i_chain.cl_cpg) !=
- ocfs2_group_bitmap_size(osb->sb) * 8) {
+ ocfs2_group_bitmap_size(osb->sb, 0) * 8) {
mlog(ML_ERROR, "The disk is too old and small. "
"Force to do offline resize.");
ret = -EINVAL;
@@ -496,7 +496,7 @@ int ocfs2_group_add(struct inode *inode, struct ocfs2_new_group_input *input)
fe = (struct ocfs2_dinode *)main_bm_bh->b_data;
if (le16_to_cpu(fe->id2.i_chain.cl_cpg) !=
- ocfs2_group_bitmap_size(osb->sb) * 8) {
+ ocfs2_group_bitmap_size(osb->sb, 0) * 8) {
mlog(ML_ERROR, "The disk is too old and small."
" Force to do offline resize.");
ret = -EINVAL;
diff --git a/fs/ocfs2/suballoc.c b/fs/ocfs2/suballoc.c
index f8aedb3..b82a667 100644
--- a/fs/ocfs2/suballoc.c
+++ b/fs/ocfs2/suballoc.c
@@ -364,7 +364,7 @@ static int ocfs2_block_group_fill(handle_t *handle,
memset(bg, 0, sb->s_blocksize);
strcpy(bg->bg_signature, OCFS2_GROUP_DESC_SIGNATURE);
bg->bg_generation = cpu_to_le32(OCFS2_SB(sb)->fs_generation);
- bg->bg_size = cpu_to_le16(ocfs2_group_bitmap_size(sb));
+ bg->bg_size = cpu_to_le16(ocfs2_group_bitmap_size(sb, 1));
bg->bg_bits = cpu_to_le16(ocfs2_bits_per_group(cl));
bg->bg_chain = cpu_to_le16(my_chain);
bg->bg_next_group = cl->cl_recs[my_chain].c_blkno;
diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
index 79d7d4c..9bbed28 100644
--- a/fs/ocfs2/super.c
+++ b/fs/ocfs2/super.c
@@ -2277,7 +2277,7 @@ static int ocfs2_initialize_super(struct super_block *sb,
osb->osb_clusters_at_boot = OCFS2_I(inode)->ip_clusters;
iput(inode);
- osb->bitmap_cpg = ocfs2_group_bitmap_size(sb) * 8;
+ osb->bitmap_cpg = ocfs2_group_bitmap_size(sb, 0) * 8;
status = ocfs2_init_slot_info(osb);
if (status < 0) {
--
1.5.5
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