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> 29d755fb38SEric Sandeen #include <linux/blkdev.h> 309bffad1eSTheodore Ts'o 313dcf5451SChristoph Hellwig #include "ext4.h" 323dcf5451SChristoph Hellwig #include "ext4_jbd2.h" 33ac27a0ecSDave Kleikamp 349bffad1eSTheodore Ts'o #include <trace/events/ext4.h> 359bffad1eSTheodore Ts'o 36ac27a0ecSDave Kleikamp /* 3714ece102SFrank Mayhar * If we're not journaling and this is a just-created file, we have to 3814ece102SFrank Mayhar * sync our parent directory (if it was freshly created) since 3914ece102SFrank Mayhar * otherwise it will only be written by writeback, leaving a huge 4014ece102SFrank Mayhar * window during which a crash may lose the file. This may apply for 4114ece102SFrank Mayhar * the parent directory's parent as well, and so on recursively, if 4214ece102SFrank Mayhar * they are also freshly created. 4314ece102SFrank Mayhar */ 440893ed45SCurt Wohlgemuth static int ext4_sync_parent(struct inode *inode) 4514ece102SFrank Mayhar { 4614ece102SFrank Mayhar struct dentry *dentry = NULL; 47d59729f4STheodore Ts'o struct inode *next; 480893ed45SCurt Wohlgemuth int ret = 0; 4914ece102SFrank Mayhar 50d59729f4STheodore Ts'o if (!ext4_test_inode_state(inode, EXT4_STATE_NEWENTRY)) 51d59729f4STheodore Ts'o return 0; 52d59729f4STheodore Ts'o inode = igrab(inode); 53d59729f4STheodore Ts'o while (ext4_test_inode_state(inode, EXT4_STATE_NEWENTRY)) { 5414ece102SFrank Mayhar ext4_clear_inode_state(inode, EXT4_STATE_NEWENTRY); 559f713878SAl Viro dentry = d_find_any_alias(inode); 56d59729f4STheodore Ts'o if (!dentry) 5714ece102SFrank Mayhar break; 582b0143b5SDavid Howells next = igrab(d_inode(dentry->d_parent)); 59d59729f4STheodore Ts'o dput(dentry); 60d59729f4STheodore Ts'o if (!next) 61d59729f4STheodore Ts'o break; 62d59729f4STheodore Ts'o iput(inode); 63d59729f4STheodore Ts'o inode = next; 646ae4c5a6SJan Kara /* 656ae4c5a6SJan Kara * The directory inode may have gone through rmdir by now. But 666ae4c5a6SJan Kara * the inode itself and its blocks are still allocated (we hold 676ae4c5a6SJan Kara * a reference to the inode so it didn't go through 686ae4c5a6SJan Kara * ext4_evict_inode()) and so we are safe to flush metadata 696ae4c5a6SJan Kara * blocks and the inode. 706ae4c5a6SJan Kara */ 710893ed45SCurt Wohlgemuth ret = sync_mapping_buffers(inode->i_mapping); 720893ed45SCurt Wohlgemuth if (ret) 730893ed45SCurt Wohlgemuth break; 7464744e03SGuo Chao ret = sync_inode_metadata(inode, 1); 750893ed45SCurt Wohlgemuth if (ret) 760893ed45SCurt Wohlgemuth break; 7714ece102SFrank Mayhar } 78d59729f4STheodore Ts'o iput(inode); 790893ed45SCurt Wohlgemuth return ret; 8014ece102SFrank Mayhar } 8114ece102SFrank Mayhar 8214ece102SFrank Mayhar /* 83617ba13bSMingming Cao * akpm: A new design for ext4_sync_file(). 84ac27a0ecSDave Kleikamp * 85ac27a0ecSDave Kleikamp * This is only called from sys_fsync(), sys_fdatasync() and sys_msync(). 86ac27a0ecSDave Kleikamp * There cannot be a transaction open by this task. 87ac27a0ecSDave Kleikamp * Another task could have dirtied this inode. Its data can be in any 88ac27a0ecSDave Kleikamp * state in the journalling system. 89ac27a0ecSDave Kleikamp * 90ac27a0ecSDave Kleikamp * What we do is just kick off a commit and wait on it. This will snapshot the 91ac27a0ecSDave Kleikamp * inode to disk. 92ac27a0ecSDave Kleikamp */ 93ac27a0ecSDave Kleikamp 9402c24a82SJosef Bacik int ext4_sync_file(struct file *file, loff_t start, loff_t end, int datasync) 95ac27a0ecSDave Kleikamp { 967ea80859SChristoph Hellwig struct inode *inode = file->f_mapping->host; 97b436b9beSJan Kara struct ext4_inode_info *ei = EXT4_I(inode); 98d755fb38SEric Sandeen journal_t *journal = EXT4_SB(inode->i_sb)->s_journal; 9937b10dd0SJan Kara int ret = 0, err; 100b436b9beSJan Kara tid_t commit_tid; 10193628ffbSJan Kara bool needs_barrier = false; 102ac27a0ecSDave Kleikamp 1030db1ff22STheodore Ts'o if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb)))) 1040db1ff22STheodore Ts'o return -EIO; 1050db1ff22STheodore Ts'o 106ac39849dSAneesh Kumar K.V J_ASSERT(ext4_journal_current_handle() == NULL); 107ac27a0ecSDave Kleikamp 1080562e0baSJiaying Zhang trace_ext4_sync_file_enter(file, datasync); 109ede86cc4STheodore Ts'o 110bc98a42cSDavid Howells if (sb_rdonly(inode->i_sb)) { 1114418e141SDmitry Monakhov /* Make sure that we read updated s_mount_flags value */ 1124418e141SDmitry Monakhov smp_rmb(); 1134418e141SDmitry Monakhov if (EXT4_SB(inode->i_sb)->s_mount_flags & EXT4_MF_FS_ABORTED) 1144418e141SDmitry Monakhov ret = -EROFS; 11592e6222dSJan Kara goto out; 1164418e141SDmitry Monakhov } 11737b10dd0SJan Kara 11837b10dd0SJan Kara if (!journal) { 11978d96251STheodore Ts'o ret = __generic_file_fsync(file, start, end, datasync); 1206ae4c5a6SJan Kara if (!ret) 12137b10dd0SJan Kara ret = ext4_sync_parent(inode); 12278d96251STheodore Ts'o if (test_opt(inode->i_sb, BARRIER)) 12378d96251STheodore Ts'o goto issue_flush; 12492e6222dSJan Kara goto out; 12537b10dd0SJan Kara } 12637b10dd0SJan Kara 1276acec592SJeff Layton ret = file_write_and_wait_range(file, start, end); 12802c24a82SJosef Bacik if (ret) 12902c24a82SJosef Bacik return ret; 130ac27a0ecSDave Kleikamp /* 131b436b9beSJan Kara * data=writeback,ordered: 132ac27a0ecSDave Kleikamp * The caller's filemap_fdatawrite()/wait will sync the data. 133b436b9beSJan Kara * Metadata is in the journal, we wait for proper transaction to 134b436b9beSJan Kara * commit here. 135ac27a0ecSDave Kleikamp * 136ac27a0ecSDave Kleikamp * data=journal: 137ac27a0ecSDave Kleikamp * filemap_fdatawrite won't do anything (the buffers are clean). 138617ba13bSMingming Cao * ext4_force_commit will write the file data into the journal and 139ac27a0ecSDave Kleikamp * will wait on that. 140ac27a0ecSDave Kleikamp * filemap_fdatawait() will encounter a ton of newly-dirtied pages 141ac27a0ecSDave Kleikamp * (they were dirtied by commit). But that's OK - the blocks are 142ac27a0ecSDave Kleikamp * safe in-journal, which is all fsync() needs to ensure. 143ac27a0ecSDave Kleikamp */ 1440562e0baSJiaying Zhang if (ext4_should_journal_data(inode)) { 1450562e0baSJiaying Zhang ret = ext4_force_commit(inode->i_sb); 1460562e0baSJiaying Zhang goto out; 1470562e0baSJiaying Zhang } 148ac27a0ecSDave Kleikamp 149b436b9beSJan Kara commit_tid = datasync ? ei->i_datasync_tid : ei->i_sync_tid; 15093628ffbSJan Kara if (journal->j_flags & JBD2_BARRIER && 15193628ffbSJan Kara !jbd2_trans_will_send_data_barrier(journal, commit_tid)) 15293628ffbSJan Kara needs_barrier = true; 153d76a3a77STheodore Ts'o ret = jbd2_complete_transaction(journal, commit_tid); 154a4a39040STheodore Ts'o if (needs_barrier) { 15578d96251STheodore Ts'o issue_flush: 156a4a39040STheodore Ts'o err = blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL); 157a4a39040STheodore Ts'o if (!ret) 158a4a39040STheodore Ts'o ret = err; 159a4a39040STheodore Ts'o } 1600562e0baSJiaying Zhang out: 1610562e0baSJiaying Zhang trace_ext4_sync_file_exit(inode, ret); 162ac27a0ecSDave Kleikamp return ret; 163ac27a0ecSDave Kleikamp } 164