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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>
Eric Sandeend755fb32008-07-11 19:27:31 -040029#include <linux/blkdev.h>
Theodore Ts'o9bffad12009-06-17 11:48:11 -040030
Christoph Hellwig3dcf5452008-04-29 18:13:32 -040031#include "ext4.h"
32#include "ext4_jbd2.h"
Dave Kleikampac27a0e2006-10-11 01:20:50 -070033
Theodore Ts'o9bffad12009-06-17 11:48:11 -040034#include <trace/events/ext4.h>
35
Dave Kleikampac27a0e2006-10-11 01:20:50 -070036/*
Frank Mayhar14ece102010-05-17 08:00:00 -040037 * If we're not journaling and this is a just-created file, we have to
38 * sync our parent directory (if it was freshly created) since
39 * otherwise it will only be written by writeback, leaving a huge
40 * window during which a crash may lose the file. This may apply for
41 * the parent directory's parent as well, and so on recursively, if
42 * they are also freshly created.
43 */
Curt Wohlgemuth0893ed42011-04-10 22:05:31 -040044static int ext4_sync_parent(struct inode *inode)
Frank Mayhar14ece102010-05-17 08:00:00 -040045{
46 struct dentry *dentry = NULL;
Theodore Ts'od59729f2011-07-30 12:34:19 -040047 struct inode *next;
Curt Wohlgemuth0893ed42011-04-10 22:05:31 -040048 int ret = 0;
Frank Mayhar14ece102010-05-17 08:00:00 -040049
Theodore Ts'od59729f2011-07-30 12:34:19 -040050 if (!ext4_test_inode_state(inode, EXT4_STATE_NEWENTRY))
51 return 0;
52 inode = igrab(inode);
53 while (ext4_test_inode_state(inode, EXT4_STATE_NEWENTRY)) {
Frank Mayhar14ece102010-05-17 08:00:00 -040054 ext4_clear_inode_state(inode, EXT4_STATE_NEWENTRY);
Al Viro9f713872012-06-09 13:19:12 -040055 dentry = d_find_any_alias(inode);
Theodore Ts'od59729f2011-07-30 12:34:19 -040056 if (!dentry)
Frank Mayhar14ece102010-05-17 08:00:00 -040057 break;
David Howells2b0143b2015-03-17 22:25:59 +000058 next = igrab(d_inode(dentry->d_parent));
Theodore Ts'od59729f2011-07-30 12:34:19 -040059 dput(dentry);
60 if (!next)
61 break;
62 iput(inode);
63 inode = next;
Curt Wohlgemuth0893ed42011-04-10 22:05:31 -040064 ret = sync_mapping_buffers(inode->i_mapping);
65 if (ret)
66 break;
Guo Chao64744e02012-12-10 14:06:03 -050067 ret = sync_inode_metadata(inode, 1);
Curt Wohlgemuth0893ed42011-04-10 22:05:31 -040068 if (ret)
69 break;
Frank Mayhar14ece102010-05-17 08:00:00 -040070 }
Theodore Ts'od59729f2011-07-30 12:34:19 -040071 iput(inode);
Curt Wohlgemuth0893ed42011-04-10 22:05:31 -040072 return ret;
Frank Mayhar14ece102010-05-17 08:00:00 -040073}
74
75/*
Mingming Cao617ba132006-10-11 01:20:53 -070076 * akpm: A new design for ext4_sync_file().
Dave Kleikampac27a0e2006-10-11 01:20:50 -070077 *
78 * This is only called from sys_fsync(), sys_fdatasync() and sys_msync().
79 * There cannot be a transaction open by this task.
80 * Another task could have dirtied this inode. Its data can be in any
81 * state in the journalling system.
82 *
83 * What we do is just kick off a commit and wait on it. This will snapshot the
84 * inode to disk.
85 */
86
Josef Bacik02c24a82011-07-16 20:44:56 -040087int ext4_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
Dave Kleikampac27a0e2006-10-11 01:20:50 -070088{
Christoph Hellwig7ea80852010-05-26 17:53:25 +020089 struct inode *inode = file->f_mapping->host;
Jan Karab436b9b2009-12-08 23:51:10 -050090 struct ext4_inode_info *ei = EXT4_I(inode);
Eric Sandeend755fb32008-07-11 19:27:31 -040091 journal_t *journal = EXT4_SB(inode->i_sb)->s_journal;
Jan Kara37b10dd2013-06-04 14:40:09 -040092 int ret = 0, err;
Jan Karab436b9b2009-12-08 23:51:10 -050093 tid_t commit_tid;
Jan Kara93628ff2011-05-24 12:00:54 -040094 bool needs_barrier = false;
Dave Kleikampac27a0e2006-10-11 01:20:50 -070095
Aneesh Kumar K.Vac398492007-10-16 18:38:25 -040096 J_ASSERT(ext4_journal_current_handle() == NULL);
Dave Kleikampac27a0e2006-10-11 01:20:50 -070097
Jiaying Zhang0562e0b2011-03-21 21:38:05 -040098 trace_ext4_sync_file_enter(file, datasync);
Theodore Ts'oede86cc2008-10-05 20:50:06 -040099
Dmitry Monakhov4418e1412013-06-12 22:38:04 -0400100 if (inode->i_sb->s_flags & MS_RDONLY) {
101 /* Make sure that we read updated s_mount_flags value */
102 smp_rmb();
103 if (EXT4_SB(inode->i_sb)->s_mount_flags & EXT4_MF_FS_ABORTED)
104 ret = -EROFS;
Jan Kara92e62222013-06-04 14:40:39 -0400105 goto out;
Dmitry Monakhov4418e1412013-06-12 22:38:04 -0400106 }
Jan Kara37b10dd2013-06-04 14:40:09 -0400107
108 if (!journal) {
109 ret = generic_file_fsync(file, start, end, datasync);
110 if (!ret && !hlist_empty(&inode->i_dentry))
111 ret = ext4_sync_parent(inode);
Jan Kara92e62222013-06-04 14:40:39 -0400112 goto out;
Jan Kara37b10dd2013-06-04 14:40:09 -0400113 }
114
Josef Bacik02c24a82011-07-16 20:44:56 -0400115 ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
116 if (ret)
117 return ret;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700118 /*
Jan Karab436b9b2009-12-08 23:51:10 -0500119 * data=writeback,ordered:
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700120 * The caller's filemap_fdatawrite()/wait will sync the data.
Jan Karab436b9b2009-12-08 23:51:10 -0500121 * Metadata is in the journal, we wait for proper transaction to
122 * commit here.
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700123 *
124 * data=journal:
125 * filemap_fdatawrite won't do anything (the buffers are clean).
Mingming Cao617ba132006-10-11 01:20:53 -0700126 * ext4_force_commit will write the file data into the journal and
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700127 * will wait on that.
128 * filemap_fdatawait() will encounter a ton of newly-dirtied pages
129 * (they were dirtied by commit). But that's OK - the blocks are
130 * safe in-journal, which is all fsync() needs to ensure.
131 */
Jiaying Zhang0562e0b2011-03-21 21:38:05 -0400132 if (ext4_should_journal_data(inode)) {
133 ret = ext4_force_commit(inode->i_sb);
134 goto out;
135 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700136
Jan Karab436b9b2009-12-08 23:51:10 -0500137 commit_tid = datasync ? ei->i_datasync_tid : ei->i_sync_tid;
Jan Kara93628ff2011-05-24 12:00:54 -0400138 if (journal->j_flags & JBD2_BARRIER &&
139 !jbd2_trans_will_send_data_barrier(journal, commit_tid))
140 needs_barrier = true;
Theodore Ts'od76a3a772013-04-03 22:02:52 -0400141 ret = jbd2_complete_transaction(journal, commit_tid);
Theodore Ts'oa4a39042012-08-17 09:58:17 -0400142 if (needs_barrier) {
143 err = blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL);
144 if (!ret)
145 ret = err;
146 }
Jan Kara37b10dd2013-06-04 14:40:09 -0400147out:
Jiaying Zhang0562e0b2011-03-21 21:38:05 -0400148 trace_ext4_sync_file_exit(inode, ret);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700149 return ret;
150}