/*
   * Interface between ext4 and JBD
   */

  #include "ext4_jbd2.h"

  #include <trace/events/ext4.h>

  int __ext4_journal_get_write_access(const char *where, unsigned int line,
  				    handle_t *handle, struct buffer_head *bh)

  {

  	int err = 0;
  
  	if (ext4_handle_valid(handle)) {
  		err = jbd2_journal_get_write_access(handle, bh);
  		if (err)

  			ext4_journal_abort_handle(where, line, __func__, bh,

  						  handle, err);
  	}

  	return err;
  }

  /*
   * The ext4 forget function must perform a revoke if we are freeing data
   * which has been journaled.  Metadata (eg. indirect blocks) must be
   * revoked in all cases.
   *
   * "bh" may be NULL: a metadata block may have been freed from memory
   * but there may still be a record of it in the journal, and that record
   * still needs to be revoked.
   *
   * If the handle isn't valid we're not journaling, but we still need to
   * call into ext4_journal_revoke() to put the buffer head.
   */

  int __ext4_forget(const char *where, unsigned int line, handle_t *handle,
  		  int is_metadata, struct inode *inode,
  		  struct buffer_head *bh, ext4_fsblk_t blocknr)

  {
  	int err;
  
  	might_sleep();
  
  	trace_ext4_forget(inode, is_metadata, blocknr);
  	BUFFER_TRACE(bh, "enter");
  
  	jbd_debug(4, "forgetting bh %p: is_metadata = %d, mode %o, "
  		  "data mode %x
  ",
  		  bh, is_metadata, inode->i_mode,
  		  test_opt(inode->i_sb, DATA_FLAGS));

  	/* In the no journal case, we can just do a bforget and return */
  	if (!ext4_handle_valid(handle)) {
  		bforget(bh);
  		return 0;
  	}

  	/* Never use the revoke function if we are doing full data
  	 * journaling: there is no need to, and a V1 superblock won't
  	 * support it.  Otherwise, only skip the revoke on un-journaled
  	 * data blocks. */
  
  	if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ||
  	    (!is_metadata && !ext4_should_journal_data(inode))) {
  		if (bh) {
  			BUFFER_TRACE(bh, "call jbd2_journal_forget");

  			err = jbd2_journal_forget(handle, bh);
  			if (err)

  				ext4_journal_abort_handle(where, line, __func__,
  							  bh, handle, err);

  			return err;

  		}
  		return 0;
  	}
  
  	/*
  	 * data!=journal && (is_metadata || should_journal_data(inode))
  	 */

  	BUFFER_TRACE(bh, "call jbd2_journal_revoke");
  	err = jbd2_journal_revoke(handle, blocknr, bh);
  	if (err) {

  		ext4_journal_abort_handle(where, line, __func__,
  					  bh, handle, err);

  		__ext4_abort(inode->i_sb, where, line,
  			   "error %d when attempting revoke", err);

  	}

  	BUFFER_TRACE(bh, "exit");
  	return err;
  }

  int __ext4_journal_get_create_access(const char *where, unsigned int line,

  				handle_t *handle, struct buffer_head *bh)
  {

  	int err = 0;
  
  	if (ext4_handle_valid(handle)) {
  		err = jbd2_journal_get_create_access(handle, bh);
  		if (err)

  			ext4_journal_abort_handle(where, line, __func__,
  						  bh, handle, err);

  	}

  	return err;
  }

  int __ext4_handle_dirty_metadata(const char *where, unsigned int line,
  				 handle_t *handle, struct inode *inode,
  				 struct buffer_head *bh)

  {

  	int err = 0;
  
  	if (ext4_handle_valid(handle)) {
  		err = jbd2_journal_dirty_metadata(handle, bh);

  		if (err) {
  			/* Errors can only happen if there is a bug */
  			handle->h_err = err;
  			__ext4_journal_stop(where, line, handle);
  		}

  	} else {

  		if (inode)

  			mark_buffer_dirty_inode(bh, inode);
  		else
  			mark_buffer_dirty(bh);

  		if (inode && inode_needs_sync(inode)) {
  			sync_dirty_buffer(bh);
  			if (buffer_req(bh) && !buffer_uptodate(bh)) {

  				struct ext4_super_block *es;
  
  				es = EXT4_SB(inode->i_sb)->s_es;
  				es->s_last_error_block =
  					cpu_to_le64(bh->b_blocknr);

  				ext4_error_inode(inode, where, line,
  						 bh->b_blocknr,
  					"IO error syncing itable block");

  				err = -EIO;
  			}
  		}
  	}

  	return err;
  }

  int __ext4_handle_dirty_super(const char *where, unsigned int line,
  			      handle_t *handle, struct super_block *sb)

  {
  	struct buffer_head *bh = EXT4_SB(sb)->s_sbh;
  	int err = 0;
  
  	if (ext4_handle_valid(handle)) {
  		err = jbd2_journal_dirty_metadata(handle, bh);
  		if (err)

  			ext4_journal_abort_handle(where, line, __func__,
  						  bh, handle, err);

  	} else
  		sb->s_dirt = 1;
  	return err;
  }