1 files changed, 47 insertions, 11 deletions

diff --git a/fs/ext4/ext4_jbd2.c b/fs/ext4/ext4_jbd2.c
index 451eb4045330..72a3600aedbd 100644
--- a/fs/ext4/ext4_jbd2.c
+++ b/fs/ext4/ext4_jbd2.c
@@ -38,31 +38,43 @@ static void ext4_put_nojournal(handle_t *handle)
 /*
  * Wrappers for jbd2_journal_start/end.
  */
-handle_t *__ext4_journal_start_sb(struct super_block *sb, unsigned int line,
-                                  int type, int nblocks)
+static int ext4_journal_check_start(struct super_block *sb)
 {
         journal_t *journal;
 
         might_sleep();
-
-        trace_ext4_journal_start(sb, nblocks, _RET_IP_);
         if (sb->s_flags & MS_RDONLY)
-                return ERR_PTR(-EROFS);
-
+                return -EROFS;
         WARN_ON(sb->s_writers.frozen == SB_FREEZE_COMPLETE);
         journal = EXT4_SB(sb)->s_journal;
-        if (!journal)
-                return ext4_get_nojournal();
         /*
          * Special case here: if the journal has aborted behind our
          * backs (eg. EIO in the commit thread), then we still need to
          * take the FS itself readonly cleanly.
          */
-        if (is_journal_aborted(journal)) {
+        if (journal && is_journal_aborted(journal)) {
                 ext4_abort(sb, "Detected aborted journal");
-                return ERR_PTR(-EROFS);
+                return -EROFS;
         }
-        return jbd2__journal_start(journal, nblocks, GFP_NOFS, type, line);
+        return 0;
+}
+
+handle_t *__ext4_journal_start_sb(struct super_block *sb, unsigned int line,
+                                  int type, int blocks, int rsv_blocks)
+{
+        journal_t *journal;
+        int err;
+
+        trace_ext4_journal_start(sb, blocks, rsv_blocks, _RET_IP_);
+        err = ext4_journal_check_start(sb);
+        if (err < 0)
+                return ERR_PTR(err);
+
+        journal = EXT4_SB(sb)->s_journal;
+        if (!journal)
+                return ext4_get_nojournal();
+        return jbd2__journal_start(journal, blocks, rsv_blocks, GFP_NOFS,
+                                   type, line);
 }
 
 int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle)
@@ -86,6 +98,30 @@ int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle)
         return err;
 }
 
+handle_t *__ext4_journal_start_reserved(handle_t *handle, unsigned int line,
+                                        int type)
+{
+        struct super_block *sb;
+        int err;
+
+        if (!ext4_handle_valid(handle))
+                return ext4_get_nojournal();
+
+        sb = handle->h_journal->j_private;
+        trace_ext4_journal_start_reserved(sb, handle->h_buffer_credits,
+                                          _RET_IP_);
+        err = ext4_journal_check_start(sb);
+        if (err < 0) {
+                jbd2_journal_free_reserved(handle);
+                return ERR_PTR(err);
+        }
+
+        err = jbd2_journal_start_reserved(handle, type, line);
+        if (err < 0)
+                return ERR_PTR(err);
+        return handle;
+}
+
 void ext4_journal_abort_handle(const char *caller, unsigned int line,
                                const char *err_fn, struct buffer_head *bh,
                                handle_t *handle, int err)