97 lines
2.9 KiB
C
97 lines
2.9 KiB
C
/*
|
|
* 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/time.h>
|
|
#include <linux/blkdev.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/writeback.h>
|
|
#include <linux/jbd.h>
|
|
#include <linux/ext3_fs.h>
|
|
#include <linux/ext3_jbd.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.
|
|
* 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.
|
|
*/
|
|
|
|
int ext3_sync_file(struct file *file, int datasync)
|
|
{
|
|
struct inode *inode = file->f_mapping->host;
|
|
struct ext3_inode_info *ei = EXT3_I(inode);
|
|
journal_t *journal = EXT3_SB(inode->i_sb)->s_journal;
|
|
int ret, needs_barrier = 0;
|
|
tid_t commit_tid;
|
|
|
|
if (inode->i_sb->s_flags & MS_RDONLY)
|
|
return 0;
|
|
|
|
J_ASSERT(ext3_journal_current_handle() == NULL);
|
|
|
|
/*
|
|
* data=writeback,ordered:
|
|
* The caller's filemap_fdatawrite()/wait will sync the data.
|
|
* Metadata is in the journal, we wait for a proper transaction
|
|
* to commit here.
|
|
*
|
|
* data=journal:
|
|
* filemap_fdatawrite won't do anything (the buffers are clean).
|
|
* ext3_force_commit will write the file data into the journal and
|
|
* will wait on that.
|
|
* filemap_fdatawait() will encounter a ton of newly-dirtied pages
|
|
* (they were dirtied by commit). But that's OK - the blocks are
|
|
* safe in-journal, which is all fsync() needs to ensure.
|
|
*/
|
|
if (ext3_should_journal_data(inode))
|
|
return ext3_force_commit(inode->i_sb);
|
|
|
|
if (datasync)
|
|
commit_tid = atomic_read(&ei->i_datasync_tid);
|
|
else
|
|
commit_tid = atomic_read(&ei->i_sync_tid);
|
|
|
|
if (test_opt(inode->i_sb, BARRIER) &&
|
|
!journal_trans_will_send_data_barrier(journal, commit_tid))
|
|
needs_barrier = 1;
|
|
log_start_commit(journal, commit_tid);
|
|
ret = log_wait_commit(journal, commit_tid);
|
|
|
|
/*
|
|
* In case we didn't commit a transaction, we have to flush
|
|
* disk caches manually so that data really is on persistent
|
|
* storage
|
|
*/
|
|
if (needs_barrier)
|
|
blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL,
|
|
BLKDEV_IFL_WAIT);
|
|
return ret;
|
|
}
|