1ac27a0ecSDave Kleikamp /* 2617ba13bSMingming Cao * linux/fs/ext4/fsync.c 3ac27a0ecSDave Kleikamp * 4ac27a0ecSDave Kleikamp * Copyright (C) 1993 Stephen Tweedie (sct@redhat.com) 5ac27a0ecSDave Kleikamp * from 6ac27a0ecSDave Kleikamp * Copyright (C) 1992 Remy Card (card@masi.ibp.fr) 7ac27a0ecSDave Kleikamp * Laboratoire MASI - Institut Blaise Pascal 8ac27a0ecSDave Kleikamp * Universite Pierre et Marie Curie (Paris VI) 9ac27a0ecSDave Kleikamp * from 10ac27a0ecSDave Kleikamp * linux/fs/minix/truncate.c Copyright (C) 1991, 1992 Linus Torvalds 11ac27a0ecSDave Kleikamp * 12617ba13bSMingming Cao * ext4fs fsync primitive 13ac27a0ecSDave Kleikamp * 14ac27a0ecSDave Kleikamp * Big-endian to little-endian byte-swapping/bitmaps by 15ac27a0ecSDave Kleikamp * David S. Miller (davem@caip.rutgers.edu), 1995 16ac27a0ecSDave Kleikamp * 17ac27a0ecSDave Kleikamp * Removed unnecessary code duplication for little endian machines 18ac27a0ecSDave Kleikamp * and excessive __inline__s. 19ac27a0ecSDave Kleikamp * Andi Kleen, 1997 20ac27a0ecSDave Kleikamp * 21ac27a0ecSDave Kleikamp * Major simplications and cleanup - we only need to do the metadata, because 22ac27a0ecSDave Kleikamp * we can depend on generic_block_fdatasync() to sync the data blocks. 23ac27a0ecSDave Kleikamp */ 24ac27a0ecSDave Kleikamp 25ac27a0ecSDave Kleikamp #include <linux/time.h> 26ac27a0ecSDave Kleikamp #include <linux/fs.h> 27ac27a0ecSDave Kleikamp #include <linux/sched.h> 28ac27a0ecSDave Kleikamp #include <linux/writeback.h> 29dab291afSMingming Cao #include <linux/jbd2.h> 30d755fb38SEric Sandeen #include <linux/blkdev.h> 319bffad1eSTheodore Ts'o 323dcf5451SChristoph Hellwig #include "ext4.h" 333dcf5451SChristoph Hellwig #include "ext4_jbd2.h" 34ac27a0ecSDave Kleikamp 359bffad1eSTheodore Ts'o #include <trace/events/ext4.h> 369bffad1eSTheodore Ts'o 37ac27a0ecSDave Kleikamp /* 38617ba13bSMingming Cao * akpm: A new design for ext4_sync_file(). 39ac27a0ecSDave Kleikamp * 40ac27a0ecSDave Kleikamp * This is only called from sys_fsync(), sys_fdatasync() and sys_msync(). 41ac27a0ecSDave Kleikamp * There cannot be a transaction open by this task. 42ac27a0ecSDave Kleikamp * Another task could have dirtied this inode. Its data can be in any 43ac27a0ecSDave Kleikamp * state in the journalling system. 44ac27a0ecSDave Kleikamp * 45ac27a0ecSDave Kleikamp * What we do is just kick off a commit and wait on it. This will snapshot the 46ac27a0ecSDave Kleikamp * inode to disk. 478d5d02e6SMingming Cao * 488d5d02e6SMingming Cao * i_mutex lock is held when entering and exiting this function 49ac27a0ecSDave Kleikamp */ 50ac27a0ecSDave Kleikamp 51617ba13bSMingming Cao int ext4_sync_file(struct file *file, struct dentry *dentry, int datasync) 52ac27a0ecSDave Kleikamp { 53ac27a0ecSDave Kleikamp struct inode *inode = dentry->d_inode; 54b436b9beSJan Kara struct ext4_inode_info *ei = EXT4_I(inode); 55d755fb38SEric Sandeen journal_t *journal = EXT4_SB(inode->i_sb)->s_journal; 56b436b9beSJan Kara int ret; 57b436b9beSJan Kara tid_t commit_tid; 58ac27a0ecSDave Kleikamp 59ac39849dSAneesh Kumar K.V J_ASSERT(ext4_journal_current_handle() == NULL); 60ac27a0ecSDave Kleikamp 619bffad1eSTheodore Ts'o trace_ext4_sync_file(file, dentry, datasync); 62ede86cc4STheodore Ts'o 63b436b9beSJan Kara if (inode->i_sb->s_flags & MS_RDONLY) 64b436b9beSJan Kara return 0; 65b436b9beSJan Kara 668d5d02e6SMingming Cao ret = flush_aio_dio_completed_IO(inode); 678d5d02e6SMingming Cao if (ret < 0) 686b17d902STheodore Ts'o return ret; 69b436b9beSJan Kara 70b436b9beSJan Kara if (!journal) 71b436b9beSJan Kara return simple_fsync(file, dentry, datasync); 72b436b9beSJan Kara 73ac27a0ecSDave Kleikamp /* 74b436b9beSJan Kara * data=writeback,ordered: 75ac27a0ecSDave Kleikamp * The caller's filemap_fdatawrite()/wait will sync the data. 76b436b9beSJan Kara * Metadata is in the journal, we wait for proper transaction to 77b436b9beSJan Kara * commit here. 78ac27a0ecSDave Kleikamp * 79ac27a0ecSDave Kleikamp * data=journal: 80ac27a0ecSDave Kleikamp * filemap_fdatawrite won't do anything (the buffers are clean). 81617ba13bSMingming Cao * ext4_force_commit will write the file data into the journal and 82ac27a0ecSDave Kleikamp * will wait on that. 83ac27a0ecSDave Kleikamp * filemap_fdatawait() will encounter a ton of newly-dirtied pages 84ac27a0ecSDave Kleikamp * (they were dirtied by commit). But that's OK - the blocks are 85ac27a0ecSDave Kleikamp * safe in-journal, which is all fsync() needs to ensure. 86ac27a0ecSDave Kleikamp */ 876b17d902STheodore Ts'o if (ext4_should_journal_data(inode)) 886b17d902STheodore Ts'o return ext4_force_commit(inode->i_sb); 89ac27a0ecSDave Kleikamp 90b436b9beSJan Kara commit_tid = datasync ? ei->i_datasync_tid : ei->i_sync_tid; 91cc3e1beaSTheodore Ts'o if (jbd2_log_start_commit(journal, commit_tid)) { 92cc3e1beaSTheodore Ts'o /* 93cc3e1beaSTheodore Ts'o * When the journal is on a different device than the 94cc3e1beaSTheodore Ts'o * fs data disk, we need to issue the barrier in 95cc3e1beaSTheodore Ts'o * writeback mode. (In ordered mode, the jbd2 layer 96cc3e1beaSTheodore Ts'o * will take care of issuing the barrier. In 97cc3e1beaSTheodore Ts'o * data=journal, all of the data blocks are written to 98cc3e1beaSTheodore Ts'o * the journal device.) 99cc3e1beaSTheodore Ts'o */ 100cc3e1beaSTheodore Ts'o if (ext4_should_writeback_data(inode) && 101cc3e1beaSTheodore Ts'o (journal->j_fs_dev != journal->j_dev) && 102cc3e1beaSTheodore Ts'o (journal->j_flags & JBD2_BARRIER)) 103cc3e1beaSTheodore Ts'o blkdev_issue_flush(inode->i_sb->s_bdev, NULL); 104b436b9beSJan Kara jbd2_log_wait_commit(journal, commit_tid); 105cc3e1beaSTheodore Ts'o } else if (journal->j_flags & JBD2_BARRIER) 1065f3481e9SChristoph Hellwig blkdev_issue_flush(inode->i_sb->s_bdev, NULL); 107ac27a0ecSDave Kleikamp return ret; 108ac27a0ecSDave Kleikamp } 109