188 lines
5.2 KiB
C
188 lines
5.2 KiB
C
|
// SPDX-License-Identifier: GPL-2.0
|
||
|
/*
|
||
|
* linux/fs/ext4/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
|
||
|
*
|
||
|
* ext4fs 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/fs.h>
|
||
|
#include <linux/sched.h>
|
||
|
#include <linux/writeback.h>
|
||
|
#include <linux/blkdev.h>
|
||
|
|
||
|
#include "ext4.h"
|
||
|
#include "ext4_jbd2.h"
|
||
|
|
||
|
#include <trace/events/ext4.h>
|
||
|
|
||
|
/*
|
||
|
* If we're not journaling and this is a just-created file, we have to
|
||
|
* sync our parent directory (if it was freshly created) since
|
||
|
* otherwise it will only be written by writeback, leaving a huge
|
||
|
* window during which a crash may lose the file. This may apply for
|
||
|
* the parent directory's parent as well, and so on recursively, if
|
||
|
* they are also freshly created.
|
||
|
*/
|
||
|
static int ext4_sync_parent(struct inode *inode)
|
||
|
{
|
||
|
struct dentry *dentry, *next;
|
||
|
int ret = 0;
|
||
|
|
||
|
if (!ext4_test_inode_state(inode, EXT4_STATE_NEWENTRY))
|
||
|
return 0;
|
||
|
dentry = d_find_any_alias(inode);
|
||
|
if (!dentry)
|
||
|
return 0;
|
||
|
while (ext4_test_inode_state(inode, EXT4_STATE_NEWENTRY)) {
|
||
|
ext4_clear_inode_state(inode, EXT4_STATE_NEWENTRY);
|
||
|
|
||
|
next = dget_parent(dentry);
|
||
|
dput(dentry);
|
||
|
dentry = next;
|
||
|
inode = dentry->d_inode;
|
||
|
|
||
|
/*
|
||
|
* The directory inode may have gone through rmdir by now. But
|
||
|
* the inode itself and its blocks are still allocated (we hold
|
||
|
* a reference to the inode via its dentry), so it didn't go
|
||
|
* through ext4_evict_inode()) and so we are safe to flush
|
||
|
* metadata blocks and the inode.
|
||
|
*/
|
||
|
ret = sync_mapping_buffers(inode->i_mapping);
|
||
|
if (ret)
|
||
|
break;
|
||
|
ret = sync_inode_metadata(inode, 1);
|
||
|
if (ret)
|
||
|
break;
|
||
|
}
|
||
|
dput(dentry);
|
||
|
return ret;
|
||
|
}
|
||
|
|
||
|
static int ext4_fsync_nojournal(struct inode *inode, bool datasync,
|
||
|
bool *needs_barrier)
|
||
|
{
|
||
|
int ret, err;
|
||
|
|
||
|
ret = sync_mapping_buffers(inode->i_mapping);
|
||
|
if (!(inode->i_state & I_DIRTY_ALL))
|
||
|
return ret;
|
||
|
if (datasync && !(inode->i_state & I_DIRTY_DATASYNC))
|
||
|
return ret;
|
||
|
|
||
|
err = sync_inode_metadata(inode, 1);
|
||
|
if (!ret)
|
||
|
ret = err;
|
||
|
|
||
|
if (!ret)
|
||
|
ret = ext4_sync_parent(inode);
|
||
|
if (test_opt(inode->i_sb, BARRIER))
|
||
|
*needs_barrier = true;
|
||
|
|
||
|
return ret;
|
||
|
}
|
||
|
|
||
|
static int ext4_fsync_journal(struct inode *inode, bool datasync,
|
||
|
bool *needs_barrier)
|
||
|
{
|
||
|
struct ext4_inode_info *ei = EXT4_I(inode);
|
||
|
journal_t *journal = EXT4_SB(inode->i_sb)->s_journal;
|
||
|
tid_t commit_tid = datasync ? ei->i_datasync_tid : ei->i_sync_tid;
|
||
|
|
||
|
if (journal->j_flags & JBD2_BARRIER &&
|
||
|
!jbd2_trans_will_send_data_barrier(journal, commit_tid))
|
||
|
*needs_barrier = true;
|
||
|
|
||
|
return ext4_fc_commit(journal, commit_tid);
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
* akpm: A new design for ext4_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 ext4_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
|
||
|
{
|
||
|
int ret = 0, err;
|
||
|
bool needs_barrier = false;
|
||
|
struct inode *inode = file->f_mapping->host;
|
||
|
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
|
||
|
|
||
|
if (unlikely(ext4_forced_shutdown(sbi)))
|
||
|
return -EIO;
|
||
|
|
||
|
ASSERT(ext4_journal_current_handle() == NULL);
|
||
|
|
||
|
trace_ext4_sync_file_enter(file, datasync);
|
||
|
|
||
|
if (sb_rdonly(inode->i_sb)) {
|
||
|
/* Make sure that we read updated s_mount_flags value */
|
||
|
smp_rmb();
|
||
|
if (ext4_test_mount_flag(inode->i_sb, EXT4_MF_FS_ABORTED))
|
||
|
ret = -EROFS;
|
||
|
goto out;
|
||
|
}
|
||
|
|
||
|
ret = file_write_and_wait_range(file, start, end);
|
||
|
if (ret)
|
||
|
goto out;
|
||
|
|
||
|
/*
|
||
|
* data=writeback,ordered:
|
||
|
* The caller's filemap_fdatawrite()/wait will sync the data.
|
||
|
* Metadata is in the journal, we wait for proper transaction to
|
||
|
* commit here.
|
||
|
*
|
||
|
* data=journal:
|
||
|
* filemap_fdatawrite won't do anything (the buffers are clean).
|
||
|
* ext4_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 (!sbi->s_journal)
|
||
|
ret = ext4_fsync_nojournal(inode, datasync, &needs_barrier);
|
||
|
else if (ext4_should_journal_data(inode))
|
||
|
ret = ext4_force_commit(inode->i_sb);
|
||
|
else
|
||
|
ret = ext4_fsync_journal(inode, datasync, &needs_barrier);
|
||
|
|
||
|
if (needs_barrier) {
|
||
|
err = blkdev_issue_flush(inode->i_sb->s_bdev);
|
||
|
if (!ret)
|
||
|
ret = err;
|
||
|
}
|
||
|
out:
|
||
|
err = file_check_and_advance_wb_err(file);
|
||
|
if (ret == 0)
|
||
|
ret = err;
|
||
|
trace_ext4_sync_file_exit(inode, ret);
|
||
|
return ret;
|
||
|
}
|