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Dave Kleikampac27a0e2006-10-11 01:20:50 -07001/*
Mingming Cao617ba132006-10-11 01:20:53 -07002 * linux/fs/ext4/fsync.c
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003 *
4 * Copyright (C) 1993 Stephen Tweedie (sct@redhat.com)
5 * from
6 * Copyright (C) 1992 Remy Card (card@masi.ibp.fr)
7 * Laboratoire MASI - Institut Blaise Pascal
8 * Universite Pierre et Marie Curie (Paris VI)
9 * from
10 * linux/fs/minix/truncate.c Copyright (C) 1991, 1992 Linus Torvalds
11 *
Mingming Cao617ba132006-10-11 01:20:53 -070012 * ext4fs fsync primitive
Dave Kleikampac27a0e2006-10-11 01:20:50 -070013 *
14 * Big-endian to little-endian byte-swapping/bitmaps by
15 * David S. Miller (davem@caip.rutgers.edu), 1995
16 *
17 * Removed unnecessary code duplication for little endian machines
18 * and excessive __inline__s.
19 * Andi Kleen, 1997
20 *
21 * Major simplications and cleanup - we only need to do the metadata, because
22 * we can depend on generic_block_fdatasync() to sync the data blocks.
23 */
24
25#include <linux/time.h>
26#include <linux/fs.h>
27#include <linux/sched.h>
28#include <linux/writeback.h>
Mingming Caodab291a2006-10-11 01:21:01 -070029#include <linux/jbd2.h>
Eric Sandeend755fb32008-07-11 19:27:31 -040030#include <linux/blkdev.h>
Theodore Ts'o9bffad12009-06-17 11:48:11 -040031
Christoph Hellwig3dcf5452008-04-29 18:13:32 -040032#include "ext4.h"
33#include "ext4_jbd2.h"
Dave Kleikampac27a0e2006-10-11 01:20:50 -070034
Theodore Ts'o9bffad12009-06-17 11:48:11 -040035#include <trace/events/ext4.h>
36
Dave Kleikampac27a0e2006-10-11 01:20:50 -070037/*
Frank Mayhar14ece102010-05-17 08:00:00 -040038 * If we're not journaling and this is a just-created file, we have to
39 * sync our parent directory (if it was freshly created) since
40 * otherwise it will only be written by writeback, leaving a huge
41 * window during which a crash may lose the file. This may apply for
42 * the parent directory's parent as well, and so on recursively, if
43 * they are also freshly created.
44 */
Curt Wohlgemuth0893ed42011-04-10 22:05:31 -040045static int ext4_sync_parent(struct inode *inode)
Frank Mayhar14ece102010-05-17 08:00:00 -040046{
47 struct dentry *dentry = NULL;
Theodore Ts'od59729f2011-07-30 12:34:19 -040048 struct inode *next;
Curt Wohlgemuth0893ed42011-04-10 22:05:31 -040049 int ret = 0;
Frank Mayhar14ece102010-05-17 08:00:00 -040050
Theodore Ts'od59729f2011-07-30 12:34:19 -040051 if (!ext4_test_inode_state(inode, EXT4_STATE_NEWENTRY))
52 return 0;
53 inode = igrab(inode);
54 while (ext4_test_inode_state(inode, EXT4_STATE_NEWENTRY)) {
Frank Mayhar14ece102010-05-17 08:00:00 -040055 ext4_clear_inode_state(inode, EXT4_STATE_NEWENTRY);
Al Viro9f713872012-06-09 13:19:12 -040056 dentry = d_find_any_alias(inode);
Theodore Ts'od59729f2011-07-30 12:34:19 -040057 if (!dentry)
Frank Mayhar14ece102010-05-17 08:00:00 -040058 break;
Theodore Ts'od59729f2011-07-30 12:34:19 -040059 next = igrab(dentry->d_parent->d_inode);
60 dput(dentry);
61 if (!next)
62 break;
63 iput(inode);
64 inode = next;
Curt Wohlgemuth0893ed42011-04-10 22:05:31 -040065 ret = sync_mapping_buffers(inode->i_mapping);
66 if (ret)
67 break;
Guo Chao64744e02012-12-10 14:06:03 -050068 ret = sync_inode_metadata(inode, 1);
Curt Wohlgemuth0893ed42011-04-10 22:05:31 -040069 if (ret)
70 break;
Frank Mayhar14ece102010-05-17 08:00:00 -040071 }
Theodore Ts'od59729f2011-07-30 12:34:19 -040072 iput(inode);
Curt Wohlgemuth0893ed42011-04-10 22:05:31 -040073 return ret;
Frank Mayhar14ece102010-05-17 08:00:00 -040074}
75
76/*
Mingming Cao617ba132006-10-11 01:20:53 -070077 * akpm: A new design for ext4_sync_file().
Dave Kleikampac27a0e2006-10-11 01:20:50 -070078 *
79 * This is only called from sys_fsync(), sys_fdatasync() and sys_msync().
80 * There cannot be a transaction open by this task.
81 * Another task could have dirtied this inode. Its data can be in any
82 * state in the journalling system.
83 *
84 * What we do is just kick off a commit and wait on it. This will snapshot the
85 * inode to disk.
86 */
87
Josef Bacik02c24a82011-07-16 20:44:56 -040088int ext4_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
Dave Kleikampac27a0e2006-10-11 01:20:50 -070089{
Christoph Hellwig7ea80852010-05-26 17:53:25 +020090 struct inode *inode = file->f_mapping->host;
Jan Karab436b9b2009-12-08 23:51:10 -050091 struct ext4_inode_info *ei = EXT4_I(inode);
Eric Sandeend755fb32008-07-11 19:27:31 -040092 journal_t *journal = EXT4_SB(inode->i_sb)->s_journal;
Jan Kara37b10dd2013-06-04 14:40:09 -040093 int ret = 0, err;
Jan Karab436b9b2009-12-08 23:51:10 -050094 tid_t commit_tid;
Jan Kara93628ff2011-05-24 12:00:54 -040095 bool needs_barrier = false;
Dave Kleikampac27a0e2006-10-11 01:20:50 -070096
Aneesh Kumar K.Vac398492007-10-16 18:38:25 -040097 J_ASSERT(ext4_journal_current_handle() == NULL);
Dave Kleikampac27a0e2006-10-11 01:20:50 -070098
Jiaying Zhang0562e0b2011-03-21 21:38:05 -040099 trace_ext4_sync_file_enter(file, datasync);
Theodore Ts'oede86cc2008-10-05 20:50:06 -0400100
Dmitry Monakhov4418e1412013-06-12 22:38:04 -0400101 if (inode->i_sb->s_flags & MS_RDONLY) {
102 /* Make sure that we read updated s_mount_flags value */
103 smp_rmb();
104 if (EXT4_SB(inode->i_sb)->s_mount_flags & EXT4_MF_FS_ABORTED)
105 ret = -EROFS;
Jan Kara92e62222013-06-04 14:40:39 -0400106 goto out;
Dmitry Monakhov4418e1412013-06-12 22:38:04 -0400107 }
Jan Kara37b10dd2013-06-04 14:40:09 -0400108
109 if (!journal) {
110 ret = generic_file_fsync(file, start, end, datasync);
111 if (!ret && !hlist_empty(&inode->i_dentry))
112 ret = ext4_sync_parent(inode);
Jan Kara92e62222013-06-04 14:40:39 -0400113 goto out;
Jan Kara37b10dd2013-06-04 14:40:09 -0400114 }
115
Josef Bacik02c24a82011-07-16 20:44:56 -0400116 ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
117 if (ret)
118 return ret;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700119 /*
Jan Karab436b9b2009-12-08 23:51:10 -0500120 * data=writeback,ordered:
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700121 * The caller's filemap_fdatawrite()/wait will sync the data.
Jan Karab436b9b2009-12-08 23:51:10 -0500122 * Metadata is in the journal, we wait for proper transaction to
123 * commit here.
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700124 *
125 * data=journal:
126 * filemap_fdatawrite won't do anything (the buffers are clean).
Mingming Cao617ba132006-10-11 01:20:53 -0700127 * ext4_force_commit will write the file data into the journal and
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700128 * will wait on that.
129 * filemap_fdatawait() will encounter a ton of newly-dirtied pages
130 * (they were dirtied by commit). But that's OK - the blocks are
131 * safe in-journal, which is all fsync() needs to ensure.
132 */
Jiaying Zhang0562e0b2011-03-21 21:38:05 -0400133 if (ext4_should_journal_data(inode)) {
134 ret = ext4_force_commit(inode->i_sb);
135 goto out;
136 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700137
Jan Karab436b9b2009-12-08 23:51:10 -0500138 commit_tid = datasync ? ei->i_datasync_tid : ei->i_sync_tid;
Jan Kara93628ff2011-05-24 12:00:54 -0400139 if (journal->j_flags & JBD2_BARRIER &&
140 !jbd2_trans_will_send_data_barrier(journal, commit_tid))
141 needs_barrier = true;
Theodore Ts'od76a3a772013-04-03 22:02:52 -0400142 ret = jbd2_complete_transaction(journal, commit_tid);
Theodore Ts'oa4a39042012-08-17 09:58:17 -0400143 if (needs_barrier) {
144 err = blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL);
145 if (!ret)
146 ret = err;
147 }
Jan Kara37b10dd2013-06-04 14:40:09 -0400148out:
Jiaying Zhang0562e0b2011-03-21 21:38:05 -0400149 trace_ext4_sync_file_exit(inode, ret);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700150 return ret;
151}