1 files changed, 39 insertions, 5 deletions

diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c
index 7ef18fc656c2..469086b9f99b 100644
--- a/fs/nilfs2/segment.c
+++ b/fs/nilfs2/segment.c
@@ -305,7 +305,6 @@ static void nilfs_transaction_lock(struct super_block *sb,
         ti->ti_count = 0;
         ti->ti_save = cur_ti;
         ti->ti_magic = NILFS_TI_MAGIC;
-        INIT_LIST_HEAD(&ti->ti_garbage);
         current->journal_info = ti;
 
         for (;;) {
@@ -332,8 +331,6 @@ static void nilfs_transaction_unlock(struct super_block *sb)
 
         up_write(&nilfs->ns_segctor_sem);
         current->journal_info = ti->ti_save;
-        if (!list_empty(&ti->ti_garbage))
-                nilfs_dispose_list(nilfs, &ti->ti_garbage, 0);
 }
 
 static void *nilfs_segctor_map_segsum_entry(struct nilfs_sc_info *sci,
@@ -746,6 +743,15 @@ static void nilfs_dispose_list(struct the_nilfs *nilfs,
         }
 }
 
+static void nilfs_iput_work_func(struct work_struct *work)
+{
+        struct nilfs_sc_info *sci = container_of(work, struct nilfs_sc_info,
+                                                 sc_iput_work);
+        struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
+
+        nilfs_dispose_list(nilfs, &sci->sc_iput_queue, 0);
+}
+
 static int nilfs_test_metadata_dirty(struct the_nilfs *nilfs,
                                      struct nilfs_root *root)
 {
@@ -1900,8 +1906,8 @@ static int nilfs_segctor_collect_dirty_files(struct nilfs_sc_info *sci,
 static void nilfs_segctor_drop_written_files(struct nilfs_sc_info *sci,
                                              struct the_nilfs *nilfs)
 {
-        struct nilfs_transaction_info *ti = current->journal_info;
         struct nilfs_inode_info *ii, *n;
+        int defer_iput = false;
 
         spin_lock(&nilfs->ns_inode_lock);
         list_for_each_entry_safe(ii, n, &sci->sc_dirty_files, i_dirty) {
@@ -1912,9 +1918,24 @@ static void nilfs_segctor_drop_written_files(struct nilfs_sc_info *sci,
                 clear_bit(NILFS_I_BUSY, &ii->i_state);
                 brelse(ii->i_bh);
                 ii->i_bh = NULL;
-                list_move_tail(&ii->i_dirty, &ti->ti_garbage);
+                list_del_init(&ii->i_dirty);
+                if (!ii->vfs_inode.i_nlink) {
+                        /*
+                         * Defer calling iput() to avoid a deadlock
+                         * over I_SYNC flag for inodes with i_nlink == 0
+                         */
+                        list_add_tail(&ii->i_dirty, &sci->sc_iput_queue);
+                        defer_iput = true;
+                } else {
+                        spin_unlock(&nilfs->ns_inode_lock);
+                        iput(&ii->vfs_inode);
+                        spin_lock(&nilfs->ns_inode_lock);
+                }
         }
         spin_unlock(&nilfs->ns_inode_lock);
+
+        if (defer_iput)
+                schedule_work(&sci->sc_iput_work);
 }
 
 /*
@@ -2583,6 +2604,8 @@ static struct nilfs_sc_info *nilfs_segctor_new(struct super_block *sb,
         INIT_LIST_HEAD(&sci->sc_segbufs);
         INIT_LIST_HEAD(&sci->sc_write_logs);
         INIT_LIST_HEAD(&sci->sc_gc_inodes);
+        INIT_LIST_HEAD(&sci->sc_iput_queue);
+        INIT_WORK(&sci->sc_iput_work, nilfs_iput_work_func);
         init_timer(&sci->sc_timer);
 
         sci->sc_interval = HZ * NILFS_SC_DEFAULT_TIMEOUT;
@@ -2609,6 +2632,8 @@ static void nilfs_segctor_write_out(struct nilfs_sc_info *sci)
                 ret = nilfs_segctor_construct(sci, SC_LSEG_SR);
                 nilfs_transaction_unlock(sci->sc_super);
 
+                flush_work(&sci->sc_iput_work);
+
         } while (ret && retrycount-- > 0);
 }
 
@@ -2633,6 +2658,9 @@ static void nilfs_segctor_destroy(struct nilfs_sc_info *sci)
                 || sci->sc_seq_request != sci->sc_seq_done);
         spin_unlock(&sci->sc_state_lock);
 
+        if (flush_work(&sci->sc_iput_work))
+                flag = true;
+
         if (flag || !nilfs_segctor_confirm(sci))
                 nilfs_segctor_write_out(sci);
 
@@ -2642,6 +2670,12 @@ static void nilfs_segctor_destroy(struct nilfs_sc_info *sci)
                 nilfs_dispose_list(nilfs, &sci->sc_dirty_files, 1);
         }
 
+        if (!list_empty(&sci->sc_iput_queue)) {
+                nilfs_warning(sci->sc_super, __func__,
+                              "iput queue is not empty\n");
+                nilfs_dispose_list(nilfs, &sci->sc_iput_queue, 1);
+        }
+
         WARN_ON(!list_empty(&sci->sc_segbufs));
         WARN_ON(!list_empty(&sci->sc_write_logs));