ocfs2: rollback alloc_dinode counts when ocfs2_block_group_set_bits() failed

After updating alloc_dinode counts in ocfs2_alloc_dinode_update_counts(),
if ocfs2_alloc_dinode_update_bitmap() failed, there is a rare case that
some space may be lost.

So, roll back alloc_dinode counts when ocfs2_block_group_set_bits()
failed.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Younger Liu <younger.liucn@gmail.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 32 insertions, 2 deletions

diff --git a/fs/ocfs2/move_extents.c b/fs/ocfs2/move_extents.c
index 3ca939552d9c..599eb4c4c8be 100644
--- a/fs/ocfs2/move_extents.c
+++ b/fs/ocfs2/move_extents.c
@@ -691,8 +691,11 @@ static int ocfs2_move_extent(struct ocfs2_move_extents_context *context,
 
         ret = ocfs2_block_group_set_bits(handle, gb_inode, gd, gd_bh,
                                          goal_bit, len);
-        if (ret)
+        if (ret) {
+                ocfs2_rollback_alloc_dinode_counts(gb_inode, gb_bh, len,
+                                               le16_to_cpu(gd->bg_chain));
                 mlog_errno(ret);
+        }
 
         /*
          * Here we should write the new page out first if we are
diff --git a/fs/ocfs2/suballoc.c b/fs/ocfs2/suballoc.c
index 482d6c2a3ea1..94fb1f3d9e62 100644
--- a/fs/ocfs2/suballoc.c
+++ b/fs/ocfs2/suballoc.c
@@ -1608,6 +1608,21 @@ out:
         return ret;
 }
 
+void ocfs2_rollback_alloc_dinode_counts(struct inode *inode,
+                                       struct buffer_head *di_bh,
+                                       u32 num_bits,
+                                       u16 chain)
+{
+        u32 tmp_used;
+        struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
+        struct ocfs2_chain_list *cl;
+
+        cl = (struct ocfs2_chain_list *)&di->id2.i_chain;
+        tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
+        di->id1.bitmap1.i_used = cpu_to_le32(tmp_used - num_bits);
+        le32_add_cpu(&cl->cl_recs[chain].c_free, num_bits);
+}
+
 static int ocfs2_bg_discontig_fix_by_rec(struct ocfs2_suballoc_result *res,
                                          struct ocfs2_extent_rec *rec,
                                          struct ocfs2_chain_list *cl)
@@ -1708,8 +1723,12 @@ static int ocfs2_search_one_group(struct ocfs2_alloc_context *ac,
 
         ret = ocfs2_block_group_set_bits(handle, alloc_inode, gd, group_bh,
                                          res->sr_bit_offset, res->sr_bits);
-        if (ret < 0)
+        if (ret < 0) {
+                ocfs2_rollback_alloc_dinode_counts(alloc_inode, ac->ac_bh,
+                                               res->sr_bits,
+                                               le16_to_cpu(gd->bg_chain));
                 mlog_errno(ret);
+        }
 
 out_loc_only:
         *bits_left = le16_to_cpu(gd->bg_free_bits_count);
@@ -1839,6 +1858,8 @@ static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
                                             res->sr_bit_offset,
                                             res->sr_bits);
         if (status < 0) {
+                ocfs2_rollback_alloc_dinode_counts(alloc_inode,
+                                        ac->ac_bh, res->sr_bits, chain);
                 mlog_errno(status);
                 goto bail;
         }
@@ -2150,6 +2171,8 @@ int ocfs2_claim_new_inode_at_loc(handle_t *handle,
                                          res->sr_bit_offset,
                                          res->sr_bits);
         if (ret < 0) {
+                ocfs2_rollback_alloc_dinode_counts(ac->ac_inode,
+                                               ac->ac_bh, res->sr_bits, chain);
                 mlog_errno(ret);
                 goto out;
         }
diff --git a/fs/ocfs2/suballoc.h b/fs/ocfs2/suballoc.h
index 218d8036b3e7..2d2501767c0c 100644
--- a/fs/ocfs2/suballoc.h
+++ b/fs/ocfs2/suballoc.h
@@ -91,6 +91,10 @@ int ocfs2_alloc_dinode_update_counts(struct inode *inode,
                          struct buffer_head *di_bh,
                          u32 num_bits,
                          u16 chain);
+void ocfs2_rollback_alloc_dinode_counts(struct inode *inode,
+                         struct buffer_head *di_bh,
+                         u32 num_bits,
+                         u16 chain);
 int ocfs2_block_group_set_bits(handle_t *handle,
                          struct inode *alloc_inode,
                          struct ocfs2_group_desc *bg,