1 files changed, 7 insertions, 24 deletions

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 2d51cd9af225..d76ec8277d3f 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -331,33 +331,17 @@ static void ext4_put_nojournal(handle_t *handle)
  * journal_end calls result in the superblock being marked dirty, so
  * that sync() will call the filesystem's write_super callback if
  * appropriate.
- *
- * To avoid j_barrier hold in userspace when a user calls freeze(),
- * ext4 prevents a new handle from being started by s_frozen, which
- * is in an upper layer.
  */
 handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks)
 {
         journal_t *journal;
-        handle_t  *handle;
 
         trace_ext4_journal_start(sb, nblocks, _RET_IP_);
         if (sb->s_flags & MS_RDONLY)
                 return ERR_PTR(-EROFS);
 
+        WARN_ON(sb->s_writers.frozen == SB_FREEZE_COMPLETE);
         journal = EXT4_SB(sb)->s_journal;
-        handle = ext4_journal_current_handle();
-
-        /*
-         * If a handle has been started, it should be allowed to
-         * finish, otherwise deadlock could happen between freeze
-         * and others(e.g. truncate) due to the restart of the
-         * journal handle if the filesystem is forzen and active
-         * handles are not stopped.
-         */
-        if (!handle)
-                vfs_check_frozen(sb, SB_FREEZE_TRANS);
-
         if (!journal)
                 return ext4_get_nojournal();
         /*
@@ -2747,6 +2731,7 @@ static int ext4_run_li_request(struct ext4_li_request *elr)
         sb = elr->lr_super;
         ngroups = EXT4_SB(sb)->s_groups_count;
 
+        sb_start_write(sb);
         for (group = elr->lr_next_group; group < ngroups; group++) {
                 gdp = ext4_get_group_desc(sb, group, NULL);
                 if (!gdp) {
@@ -2773,6 +2758,7 @@ static int ext4_run_li_request(struct ext4_li_request *elr)
                 elr->lr_next_sched = jiffies + elr->lr_timeout;
                 elr->lr_next_group = group + 1;
         }
+        sb_end_write(sb);
 
         return ret;
 }
@@ -4460,10 +4446,8 @@ int ext4_force_commit(struct super_block *sb)
                 return 0;
 
         journal = EXT4_SB(sb)->s_journal;
-        if (journal) {
-                vfs_check_frozen(sb, SB_FREEZE_TRANS);
+        if (journal)
                 ret = ext4_journal_force_commit(journal);
-        }
 
         return ret;
 }
@@ -4493,9 +4477,8 @@ static int ext4_sync_fs(struct super_block *sb, int wait)
  * gives us a chance to flush the journal completely and mark the fs clean.
  *
  * Note that only this function cannot bring a filesystem to be in a clean
- * state independently, because ext4 prevents a new handle from being started
- * by @sb->s_frozen, which stays in an upper layer.  It thus needs help from
- * the upper layer.
+ * state independently. It relies on upper layer to stop all data & metadata
+ * modifications.
  */
 static int ext4_freeze(struct super_block *sb)
 {
@@ -4522,7 +4505,7 @@ static int ext4_freeze(struct super_block *sb)
         EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
         error = ext4_commit_super(sb, 1);
 out:
-        /* we rely on s_frozen to stop further updates */
+        /* we rely on upper layer to stop further updates */
         jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
         return error;
 }