ocfs2: Some tiny bug fixes for discontiguous block allocation.

The fixes include:
1. some endian problems.
2. we should use bit/bpc in ocfs2_block_group_grow_discontig to
   allocate clusters.
3. set num_clusters properly in __ocfs2_claim_clusters.
4. change name from ocfs2_supports_discontig_bh to
   ocfs2_supports_discontig_bg.

Signed-off-by: Tao Ma <tao.ma@oracle.com>

2 files changed, 25 insertions, 15 deletions

diff --git a/fs/ocfs2/ocfs2.h b/fs/ocfs2/ocfs2.h
index d389f2714c96..c67003b6b5a2 100644
--- a/fs/ocfs2/ocfs2.h
+++ b/fs/ocfs2/ocfs2.h
@@ -491,7 +491,7 @@ static inline int ocfs2_supports_indexed_dirs(struct ocfs2_super *osb)
         return 0;
 }
 
-static inline int ocfs2_supports_discontig_bh(struct ocfs2_super *osb)
+static inline int ocfs2_supports_discontig_bg(struct ocfs2_super *osb)
 {
         if (osb->s_feature_incompat & OCFS2_FEATURE_INCOMPAT_DISCONTIG_BG)
                 return 1;
diff --git a/fs/ocfs2/suballoc.c b/fs/ocfs2/suballoc.c
index 5852a46647a2..b7491e2481ca 100644
--- a/fs/ocfs2/suballoc.c
+++ b/fs/ocfs2/suballoc.c
@@ -341,15 +341,17 @@ static void ocfs2_bg_discontig_add_extent(struct ocfs2_super *osb,
         struct ocfs2_extent_list *el = &bg->bg_list;
         struct ocfs2_extent_rec *rec;
 
-        BUG_ON(!ocfs2_supports_discontig_bh(osb));
+        BUG_ON(!ocfs2_supports_discontig_bg(osb));
         if (!el->l_next_free_rec)
                 el->l_count = cpu_to_le16(ocfs2_extent_recs_per_gd(osb->sb));
         rec = &el->l_recs[le16_to_cpu(el->l_next_free_rec)];
-        rec->e_blkno = p_blkno;
+        rec->e_blkno = cpu_to_le64(p_blkno);
         rec->e_cpos = cpu_to_le32(le16_to_cpu(bg->bg_bits) /
                                   le16_to_cpu(cl->cl_bpc));
         rec->e_leaf_clusters = cpu_to_le32(clusters);
         le16_add_cpu(&bg->bg_bits, clusters * le16_to_cpu(cl->cl_bpc));
+        le16_add_cpu(&bg->bg_free_bits_count,
+                     clusters * le16_to_cpu(cl->cl_bpc));
         le16_add_cpu(&el->l_next_free_rec, 1);
 }
 
@@ -397,7 +399,7 @@ static int ocfs2_block_group_fill(handle_t *handle,
         if (group_clusters == le16_to_cpu(cl->cl_cpg))
                 bg->bg_bits = cpu_to_le16(ocfs2_bits_per_group(cl));
         else
-                ocfs2_bg_discontig_add_extent(osb, bg, cl, bg->bg_blkno,
+                ocfs2_bg_discontig_add_extent(osb, bg, cl, group_blkno,
                                               group_clusters);
 
         /* set the 1st bit in the bitmap to account for the descriptor block */
@@ -506,8 +508,8 @@ static int ocfs2_block_group_grow_discontig(handle_t *handle,
         struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
         struct ocfs2_group_desc *bg =
                 (struct ocfs2_group_desc *)bg_bh->b_data;
-        unsigned int needed =
-                ocfs2_bits_per_group(cl) - le16_to_cpu(bg->bg_bits);
+        unsigned int needed = le16_to_cpu(cl->cl_cpg) -
+                         le16_to_cpu(bg->bg_bits) / le16_to_cpu(cl->cl_bpc);
         u32 p_cpos, clusters;
         u64 p_blkno;
         struct ocfs2_extent_list *el = &bg->bg_list;
@@ -538,10 +540,17 @@ static int ocfs2_block_group_grow_discontig(handle_t *handle,
                                               clusters);
 
                 min_bits = clusters;
-                needed = ocfs2_bits_per_group(cl) - le16_to_cpu(bg->bg_bits);
+                needed = le16_to_cpu(cl->cl_cpg) -
+                         le16_to_cpu(bg->bg_bits) / le16_to_cpu(cl->cl_bpc);
         }
 
         if (needed > 0) {
+                /*
+                 * We have used up all the extent rec but can't fill up
+                 * the cpg. So bail out.
+                 */
+                status = -ENOSPC;
+                goto bail;
         }
 
         ocfs2_journal_dirty(handle, bg_bh);
@@ -594,7 +603,7 @@ ocfs2_block_group_alloc_discontig(handle_t *handle,
         unsigned int alloc_rec = ocfs2_find_smallest_chain(cl);
         struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
 
-        if (!ocfs2_supports_discontig_bh(osb)) {
+        if (!ocfs2_supports_discontig_bg(osb)) {
                 status = -ENOSPC;
                 goto bail;
         }
@@ -670,7 +679,7 @@ static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
         struct ocfs2_chain_list *cl;
         struct ocfs2_alloc_context *ac = NULL;
         handle_t *handle = NULL;
-        u64 bg_blkno;
+        u16 alloc_rec;
         struct buffer_head *bg_bh = NULL;
         struct ocfs2_group_desc *bg;
 
@@ -726,11 +735,12 @@ static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
                 goto bail;
         }
 
-        le32_add_cpu(&cl->cl_recs[bg->bg_chain].c_free,
+        alloc_rec = le16_to_cpu(bg->bg_chain);
+        le32_add_cpu(&cl->cl_recs[alloc_rec].c_free,
                      le16_to_cpu(bg->bg_free_bits_count));
-        le32_add_cpu(&cl->cl_recs[bg->bg_chain].c_total,
+        le32_add_cpu(&cl->cl_recs[alloc_rec].c_total,
                      le16_to_cpu(bg->bg_bits));
-        cl->cl_recs[bg->bg_chain].c_blkno  = cpu_to_le64(bg_blkno);
+        cl->cl_recs[alloc_rec].c_blkno  = cpu_to_le64(bg->bg_blkno);
         if (le16_to_cpu(cl->cl_next_free_rec) < le16_to_cpu(cl->cl_count))
                 le16_add_cpu(&cl->cl_next_free_rec, 1);
 
@@ -1622,7 +1632,7 @@ static void ocfs2_bg_discontig_fix_result(struct ocfs2_alloc_context *ac,
 
         res->sr_blkno = res->sr_bg_blkno + res->sr_bit_offset;
         res->sr_bg_blkno = 0;  /* Clear it for contig block groups */
-        if (!ocfs2_supports_discontig_bh(OCFS2_SB(ac->ac_inode->i_sb)) ||
+        if (!ocfs2_supports_discontig_bg(OCFS2_SB(ac->ac_inode->i_sb)) ||
             !bg->bg_list.l_next_free_rec)
                 return;
 
@@ -2162,6 +2172,7 @@ int __ocfs2_claim_clusters(handle_t *handle,
                                                                  res.sr_bg_blkno,
                                                                  res.sr_bit_offset);
                         atomic_inc(&osb->alloc_stats.bitmap_data);
+                        *num_clusters = res.sr_bits;
                 }
         }
         if (status < 0) {
@@ -2170,8 +2181,7 @@ int __ocfs2_claim_clusters(handle_t *handle,
                 goto bail;
         }
 
-        ac->ac_bits_given += res.sr_bits;
-        *num_clusters = res.sr_bits;
+        ac->ac_bits_given += *num_clusters;
 
 bail:
         mlog_exit(status);