nilfs2: add free entries count only if clear bit operation succeeded

Three functions of the current persistent object allocator,
nilfs_palloc_commit_free_entry, nilfs_palloc_abort_alloc_entry, and
nilfs_palloc_freev functions unconditionally add a counter after doing
clear bit operation on a bitmap block.

If the clear bit operation overlapped, the counter will not add up.
This fixes the issue by making the counter operations conditional.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

1 files changed, 7 insertions, 5 deletions

diff --git a/fs/nilfs2/alloc.c b/fs/nilfs2/alloc.c
index d7fd696e595c..0a0a66d98cce 100644
--- a/fs/nilfs2/alloc.c
+++ b/fs/nilfs2/alloc.c
@@ -521,8 +521,8 @@ void nilfs_palloc_commit_free_entry(struct inode *inode,
                                     group_offset, bitmap))
                 printk(KERN_WARNING "%s: entry number %llu already freed\n",
                        __func__, (unsigned long long)req->pr_entry_nr);
-
-        nilfs_palloc_group_desc_add_entries(inode, group, desc, 1);
+        else
+                nilfs_palloc_group_desc_add_entries(inode, group, desc, 1);
 
         kunmap(req->pr_bitmap_bh->b_page);
         kunmap(req->pr_desc_bh->b_page);
@@ -558,8 +558,8 @@ void nilfs_palloc_abort_alloc_entry(struct inode *inode,
                                     group_offset, bitmap))
                 printk(KERN_WARNING "%s: entry number %llu already freed\n",
                        __func__, (unsigned long long)req->pr_entry_nr);
-
-        nilfs_palloc_group_desc_add_entries(inode, group, desc, 1);
+        else
+                nilfs_palloc_group_desc_add_entries(inode, group, desc, 1);
 
         kunmap(req->pr_bitmap_bh->b_page);
         kunmap(req->pr_desc_bh->b_page);
@@ -665,7 +665,7 @@ int nilfs_palloc_freev(struct inode *inode, __u64 *entry_nrs, size_t nitems)
                 for (j = i, n = 0;
                      (j < nitems) && nilfs_palloc_group_is_in(inode, group,
                                                               entry_nrs[j]);
-                     j++, n++) {
+                     j++) {
                         nilfs_palloc_group(inode, entry_nrs[j], &group_offset);
                         if (!nilfs_clear_bit_atomic(
                                     nilfs_mdt_bgl_lock(inode, group),
@@ -674,6 +674,8 @@ int nilfs_palloc_freev(struct inode *inode, __u64 *entry_nrs, size_t nitems)
                                        "%s: entry number %llu already freed\n",
                                        __func__,
                                        (unsigned long long)entry_nrs[j]);
+                        } else {
+                                n++;
                         }
                 }
                 nilfs_palloc_group_desc_add_entries(inode, group, desc, n);