ocfs2: fix a tiny race when truncate dio orohaned entry

Once dio crashed it will leave an entry in orphan dir.  And orphan scan
will take care of the clean up.  There is a tiny race case that the same
entry will be truncated twice and then trigger the BUG in
ocfs2_del_inode_from_orphan.

Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

4 files changed, 39 insertions, 46 deletions

diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c
index f906a250da6a..395f4b356baa 100644
--- a/fs/ocfs2/aops.c
+++ b/fs/ocfs2/aops.c
@@ -925,13 +925,23 @@ clean_orphan:
                 int update_isize = written > 0 ? 1 : 0;
                 loff_t end = update_isize ? offset + written : 0;
 
-                tmp_ret = ocfs2_del_inode_from_orphan(osb, inode,
+                tmp_ret = ocfs2_inode_lock(inode, &di_bh, 1);
+                if (tmp_ret < 0) {
+                        ret = tmp_ret;
+                        mlog_errno(ret);
+                        goto out;
+                }
+
+                tmp_ret = ocfs2_del_inode_from_orphan(osb, inode, di_bh,
                                 update_isize, end);
                 if (tmp_ret < 0) {
                         ret = tmp_ret;
+                        mlog_errno(ret);
                         goto out;
                 }
 
+                ocfs2_inode_unlock(inode, 1);
+
                 tmp_ret = jbd2_journal_force_commit(journal);
                 if (tmp_ret < 0) {
                         ret = tmp_ret;
diff --git a/fs/ocfs2/journal.c b/fs/ocfs2/journal.c
index ff531928269e..4205da06000d 100644
--- a/fs/ocfs2/journal.c
+++ b/fs/ocfs2/journal.c
@@ -2137,6 +2137,8 @@ static int ocfs2_recover_orphans(struct ocfs2_super *osb,
         struct inode *inode = NULL;
         struct inode *iter;
         struct ocfs2_inode_info *oi;
+        struct buffer_head *di_bh = NULL;
+        struct ocfs2_dinode *di = NULL;
 
         trace_ocfs2_recover_orphans(slot);
 
@@ -2157,16 +2159,22 @@ static int ocfs2_recover_orphans(struct ocfs2_super *osb,
                 iter = oi->ip_next_orphan;
                 oi->ip_next_orphan = NULL;
 
+                ret = ocfs2_rw_lock(inode, 1);
+                if (ret < 0) {
+                        mlog_errno(ret);
+                        goto next;
+                }
                 /*
                  * We need to take and drop the inode lock to
                  * force read inode from disk.
                  */
-                ret = ocfs2_inode_lock(inode, NULL, 0);
+                ret = ocfs2_inode_lock(inode, &di_bh, 1);
                 if (ret) {
                         mlog_errno(ret);
-                        goto next;
+                        goto unlock_rw;
                 }
-                ocfs2_inode_unlock(inode, 0);
+
+                di = (struct ocfs2_dinode *)di_bh->b_data;
 
                 if (inode->i_nlink == 0) {
                         spin_lock(&oi->ip_lock);
@@ -2174,43 +2182,30 @@ static int ocfs2_recover_orphans(struct ocfs2_super *osb,
                          * ocfs2_delete_inode. */
                         oi->ip_flags |= OCFS2_INODE_MAYBE_ORPHANED;
                         spin_unlock(&oi->ip_lock);
-                } else if (orphan_reco_type == ORPHAN_NEED_TRUNCATE) {
-                        struct buffer_head *di_bh = NULL;
-
-                        ret = ocfs2_rw_lock(inode, 1);
-                        if (ret) {
-                                mlog_errno(ret);
-                                goto next;
-                        }
-
-                        ret = ocfs2_inode_lock(inode, &di_bh, 1);
-                        if (ret < 0) {
-                                ocfs2_rw_unlock(inode, 1);
-                                mlog_errno(ret);
-                                goto next;
-                        }
-
+                } else if ((orphan_reco_type == ORPHAN_NEED_TRUNCATE) &&
+                                (di->i_flags & cpu_to_le32(OCFS2_DIO_ORPHANED_FL))) {
                         ret = ocfs2_truncate_file(inode, di_bh,
                                         i_size_read(inode));
-                        ocfs2_inode_unlock(inode, 1);
-                        ocfs2_rw_unlock(inode, 1);
-                        brelse(di_bh);
                         if (ret < 0) {
                                 if (ret != -ENOSPC)
                                         mlog_errno(ret);
-                                goto next;
+                                goto unlock_inode;
                         }
 
-                        ret = ocfs2_del_inode_from_orphan(osb, inode, 0, 0);
+                        ret = ocfs2_del_inode_from_orphan(osb, inode, di_bh, 0, 0);
                         if (ret)
                                 mlog_errno(ret);
 
                         wake_up(&OCFS2_I(inode)->append_dio_wq);
                 } /* else if ORPHAN_NO_NEED_TRUNCATE, do nothing */
-
+unlock_inode:
+                ocfs2_inode_unlock(inode, 1);
+unlock_rw:
+                ocfs2_rw_unlock(inode, 1);
 next:
                 iput(inode);
-
+                brelse(di_bh);
+                di_bh = NULL;
                 inode = iter;
         }
 
diff --git a/fs/ocfs2/namei.c b/fs/ocfs2/namei.c
index 176fe6afd94e..08a7a5b70494 100644
--- a/fs/ocfs2/namei.c
+++ b/fs/ocfs2/namei.c
@@ -2670,30 +2670,22 @@ bail:
 }
 
 int ocfs2_del_inode_from_orphan(struct ocfs2_super *osb,
-                struct inode *inode, int update_isize,
-                loff_t end)
+                struct inode *inode, struct buffer_head *di_bh,
+                int update_isize, loff_t end)
 {
         struct inode *orphan_dir_inode = NULL;
         struct buffer_head *orphan_dir_bh = NULL;
-        struct buffer_head *di_bh = NULL;
-        struct ocfs2_dinode *di = NULL;
+        struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
         handle_t *handle = NULL;
         int status = 0;
 
-        status = ocfs2_inode_lock(inode, &di_bh, 1);
-        if (status < 0) {
-                mlog_errno(status);
-                goto bail;
-        }
-        di = (struct ocfs2_dinode *) di_bh->b_data;
-
         orphan_dir_inode = ocfs2_get_system_file_inode(osb,
                         ORPHAN_DIR_SYSTEM_INODE,
                         le16_to_cpu(di->i_dio_orphaned_slot));
         if (!orphan_dir_inode) {
                 status = -ENOENT;
                 mlog_errno(status);
-                goto bail_unlock_inode;
+                goto bail;
         }
 
         mutex_lock(&orphan_dir_inode->i_mutex);
@@ -2702,7 +2694,7 @@ int ocfs2_del_inode_from_orphan(struct ocfs2_super *osb,
                 mutex_unlock(&orphan_dir_inode->i_mutex);
                 iput(orphan_dir_inode);
                 mlog_errno(status);
-                goto bail_unlock_inode;
+                goto bail;
         }
 
         handle = ocfs2_start_trans(osb,
@@ -2749,10 +2741,6 @@ bail_unlock_orphan:
         brelse(orphan_dir_bh);
         iput(orphan_dir_inode);
 
-bail_unlock_inode:
-        ocfs2_inode_unlock(inode, 1);
-        brelse(di_bh);
-
 bail:
         return status;
 }
diff --git a/fs/ocfs2/namei.h b/fs/ocfs2/namei.h
index 5ddecce172fa..e173329eb830 100644
--- a/fs/ocfs2/namei.h
+++ b/fs/ocfs2/namei.h
@@ -42,8 +42,8 @@ int ocfs2_create_inode_in_orphan(struct inode *dir,
 int ocfs2_add_inode_to_orphan(struct ocfs2_super *osb,
                 struct inode *inode);
 int ocfs2_del_inode_from_orphan(struct ocfs2_super *osb,
-                struct inode *inode, int update_isize,
-                loff_t end);
+                struct inode *inode, struct buffer_head *di_bh,
+                int update_isize, loff_t end);
 int ocfs2_mv_orphaned_inode_to_new(struct inode *dir,
                                    struct inode *new_inode,
                                    struct dentry *new_dentry);