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/*

 *  linux/fs/ext3/fsync.c

 *

 *  Copyright (C) 1993  Stephen Tweedie (sct@redhat.com)

 *  from

 *  Copyright (C) 1992  Remy Card (card@masi.ibp.fr)

 *                      Laboratoire MASI - Institut Blaise Pascal

 *                      Universite Pierre et Marie Curie (Paris VI)

 *  from

 *  linux/fs/minix/truncate.c   Copyright (C) 1991, 1992  Linus Torvalds

 *

 *  ext3fs fsync primitive

 *

 *  Big-endian to little-endian byte-swapping/bitmaps by

 *        David S. Miller (davem@caip.rutgers.edu), 1995

 *

 *  Removed unnecessary code duplication for little endian machines

 *  and excessive __inline__s.

 *        Andi Kleen, 1997

 *

 * Major simplications and cleanup - we only need to do the metadata, because

 * we can depend on generic_block_fdatasync() to sync the data blocks.

 */

#include <linux/sched.h>

#include <linux/fs.h>

#include <linux/jbd.h>

#include <linux/ext3_fs.h>

#include <linux/ext3_jbd.h>

#include <linux/jbd.h>

#include <linux/smp_lock.h>

/*

 * akpm: A new design for ext3_sync_file().

 *

 * This is only called from sys_fsync(), sys_fdatasync() and sys_msync().

 * There cannot be a transaction open by this task. (AKPM: quotas?)

 * Another task could have dirtied this inode.  Its data can be in any

 * state in the journalling system.

 *

 * What we do is just kick off a commit and wait on it.  This will snapshot the

 * inode to disk.

 *

 * Note that there is a serious optimisation we can make here: if the current

 * inode is not part of j_running_transaction or j_committing_transaction

 * then we have nothing to do.  That would require implementation of t_ilist,

 * which isn't too hard.

 */

int ext3_sync_file(struct file * file, struct dentry *dentry, int datasync)

{

        struct inode *inode = dentry->d_inode;

        int ret;

        J_ASSERT(ext3_journal_current_handle() == 0);

        /*

         * fsync_inode_buffers() just walks i_dirty_buffers and waits

         * on them.  It's a no-op for full data journalling because

         * i_dirty_buffers will be ampty.

         * Really, we only need to start I/O on the dirty buffers -

         * we'll end up waiting on them in commit.

         */

        ret = fsync_inode_buffers(inode);

        /* In writeback mode, we need to force out data buffers too.  In

         * the other modes, ext3_force_commit takes care of forcing out

         * just the right data blocks. */

        if (test_opt(inode->i_sb, DATA_FLAGS) == EXT3_MOUNT_WRITEBACK_DATA)

                ret |= fsync_inode_data_buffers(inode);

        ext3_force_commit(inode->i_sb);

        return ret;

}