1b2441318SGreg Kroah-Hartman // SPDX-License-Identifier: GPL-2.0 2ac27a0ecSDave Kleikamp /* 3617ba13bSMingming Cao * linux/fs/ext4/fsync.c 4ac27a0ecSDave Kleikamp * 5ac27a0ecSDave Kleikamp * Copyright (C) 1993 Stephen Tweedie (sct@redhat.com) 6ac27a0ecSDave Kleikamp * from 7ac27a0ecSDave Kleikamp * Copyright (C) 1992 Remy Card (card@masi.ibp.fr) 8ac27a0ecSDave Kleikamp * Laboratoire MASI - Institut Blaise Pascal 9ac27a0ecSDave Kleikamp * Universite Pierre et Marie Curie (Paris VI) 10ac27a0ecSDave Kleikamp * from 11ac27a0ecSDave Kleikamp * linux/fs/minix/truncate.c Copyright (C) 1991, 1992 Linus Torvalds 12ac27a0ecSDave Kleikamp * 13617ba13bSMingming Cao * ext4fs fsync primitive 14ac27a0ecSDave Kleikamp * 15ac27a0ecSDave Kleikamp * Big-endian to little-endian byte-swapping/bitmaps by 16ac27a0ecSDave Kleikamp * David S. Miller (davem@caip.rutgers.edu), 1995 17ac27a0ecSDave Kleikamp * 18ac27a0ecSDave Kleikamp * Removed unnecessary code duplication for little endian machines 19ac27a0ecSDave Kleikamp * and excessive __inline__s. 20ac27a0ecSDave Kleikamp * Andi Kleen, 1997 21ac27a0ecSDave Kleikamp * 22ac27a0ecSDave Kleikamp * Major simplications and cleanup - we only need to do the metadata, because 23ac27a0ecSDave Kleikamp * we can depend on generic_block_fdatasync() to sync the data blocks. 24ac27a0ecSDave Kleikamp */ 25ac27a0ecSDave Kleikamp 26ac27a0ecSDave Kleikamp #include <linux/time.h> 27ac27a0ecSDave Kleikamp #include <linux/fs.h> 28ac27a0ecSDave Kleikamp #include <linux/sched.h> 29ac27a0ecSDave Kleikamp #include <linux/writeback.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 /* 3814ece102SFrank Mayhar * If we're not journaling and this is a just-created file, we have to 3914ece102SFrank Mayhar * sync our parent directory (if it was freshly created) since 4014ece102SFrank Mayhar * otherwise it will only be written by writeback, leaving a huge 4114ece102SFrank Mayhar * window during which a crash may lose the file. This may apply for 4214ece102SFrank Mayhar * the parent directory's parent as well, and so on recursively, if 4314ece102SFrank Mayhar * they are also freshly created. 4414ece102SFrank Mayhar */ 450893ed45SCurt Wohlgemuth static int ext4_sync_parent(struct inode *inode) 4614ece102SFrank Mayhar { 4714ece102SFrank Mayhar struct dentry *dentry = NULL; 48d59729f4STheodore Ts'o struct inode *next; 490893ed45SCurt Wohlgemuth int ret = 0; 5014ece102SFrank Mayhar 51d59729f4STheodore Ts'o if (!ext4_test_inode_state(inode, EXT4_STATE_NEWENTRY)) 52d59729f4STheodore Ts'o return 0; 53d59729f4STheodore Ts'o inode = igrab(inode); 54d59729f4STheodore Ts'o while (ext4_test_inode_state(inode, EXT4_STATE_NEWENTRY)) { 5514ece102SFrank Mayhar ext4_clear_inode_state(inode, EXT4_STATE_NEWENTRY); 569f713878SAl Viro dentry = d_find_any_alias(inode); 57d59729f4STheodore Ts'o if (!dentry) 5814ece102SFrank Mayhar break; 592b0143b5SDavid Howells next = igrab(d_inode(dentry->d_parent)); 60d59729f4STheodore Ts'o dput(dentry); 61d59729f4STheodore Ts'o if (!next) 62d59729f4STheodore Ts'o break; 63d59729f4STheodore Ts'o iput(inode); 64d59729f4STheodore Ts'o inode = next; 656ae4c5a6SJan Kara /* 666ae4c5a6SJan Kara * The directory inode may have gone through rmdir by now. But 676ae4c5a6SJan Kara * the inode itself and its blocks are still allocated (we hold 686ae4c5a6SJan Kara * a reference to the inode so it didn't go through 696ae4c5a6SJan Kara * ext4_evict_inode()) and so we are safe to flush metadata 706ae4c5a6SJan Kara * blocks and the inode. 716ae4c5a6SJan Kara */ 720893ed45SCurt Wohlgemuth ret = sync_mapping_buffers(inode->i_mapping); 730893ed45SCurt Wohlgemuth if (ret) 740893ed45SCurt Wohlgemuth break; 7564744e03SGuo Chao ret = sync_inode_metadata(inode, 1); 760893ed45SCurt Wohlgemuth if (ret) 770893ed45SCurt Wohlgemuth break; 7814ece102SFrank Mayhar } 79d59729f4STheodore Ts'o iput(inode); 800893ed45SCurt Wohlgemuth return ret; 8114ece102SFrank Mayhar } 8214ece102SFrank Mayhar 8314ece102SFrank Mayhar /* 84617ba13bSMingming Cao * akpm: A new design for ext4_sync_file(). 85ac27a0ecSDave Kleikamp * 86ac27a0ecSDave Kleikamp * This is only called from sys_fsync(), sys_fdatasync() and sys_msync(). 87ac27a0ecSDave Kleikamp * There cannot be a transaction open by this task. 88ac27a0ecSDave Kleikamp * Another task could have dirtied this inode. Its data can be in any 89ac27a0ecSDave Kleikamp * state in the journalling system. 90ac27a0ecSDave Kleikamp * 91ac27a0ecSDave Kleikamp * What we do is just kick off a commit and wait on it. This will snapshot the 92ac27a0ecSDave Kleikamp * inode to disk. 93ac27a0ecSDave Kleikamp */ 94ac27a0ecSDave Kleikamp 9502c24a82SJosef Bacik int ext4_sync_file(struct file *file, loff_t start, loff_t end, int datasync) 96ac27a0ecSDave Kleikamp { 977ea80859SChristoph Hellwig struct inode *inode = file->f_mapping->host; 98b436b9beSJan Kara struct ext4_inode_info *ei = EXT4_I(inode); 99d755fb38SEric Sandeen journal_t *journal = EXT4_SB(inode->i_sb)->s_journal; 10037b10dd0SJan Kara int ret = 0, err; 101b436b9beSJan Kara tid_t commit_tid; 10293628ffbSJan Kara bool needs_barrier = false; 103ac27a0ecSDave Kleikamp 1040db1ff22STheodore Ts'o if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb)))) 1050db1ff22STheodore Ts'o return -EIO; 1060db1ff22STheodore Ts'o 107ac39849dSAneesh Kumar K.V J_ASSERT(ext4_journal_current_handle() == NULL); 108ac27a0ecSDave Kleikamp 1090562e0baSJiaying Zhang trace_ext4_sync_file_enter(file, datasync); 110ede86cc4STheodore Ts'o 111bc98a42cSDavid Howells if (sb_rdonly(inode->i_sb)) { 1124418e141SDmitry Monakhov /* Make sure that we read updated s_mount_flags value */ 1134418e141SDmitry Monakhov smp_rmb(); 1144418e141SDmitry Monakhov if (EXT4_SB(inode->i_sb)->s_mount_flags & EXT4_MF_FS_ABORTED) 1154418e141SDmitry Monakhov ret = -EROFS; 11692e6222dSJan Kara goto out; 1174418e141SDmitry Monakhov } 11837b10dd0SJan Kara 119ad211f3eSTheodore Ts'o ret = file_write_and_wait_range(file, start, end); 120ad211f3eSTheodore Ts'o if (ret) 121ad211f3eSTheodore Ts'o return ret; 122ad211f3eSTheodore Ts'o 12337b10dd0SJan Kara if (!journal) { 124ad211f3eSTheodore Ts'o struct writeback_control wbc = { 125ad211f3eSTheodore Ts'o .sync_mode = WB_SYNC_ALL 126ad211f3eSTheodore Ts'o }; 127ad211f3eSTheodore Ts'o 128ad211f3eSTheodore Ts'o ret = ext4_write_inode(inode, &wbc); 1296ae4c5a6SJan Kara if (!ret) 13037b10dd0SJan Kara ret = ext4_sync_parent(inode); 13178d96251STheodore Ts'o if (test_opt(inode->i_sb, BARRIER)) 13278d96251STheodore Ts'o goto issue_flush; 13392e6222dSJan Kara goto out; 13437b10dd0SJan Kara } 13537b10dd0SJan Kara 136ac27a0ecSDave Kleikamp /* 137b436b9beSJan Kara * data=writeback,ordered: 138ac27a0ecSDave Kleikamp * The caller's filemap_fdatawrite()/wait will sync the data. 139b436b9beSJan Kara * Metadata is in the journal, we wait for proper transaction to 140b436b9beSJan Kara * commit here. 141ac27a0ecSDave Kleikamp * 142ac27a0ecSDave Kleikamp * data=journal: 143ac27a0ecSDave Kleikamp * filemap_fdatawrite won't do anything (the buffers are clean). 144617ba13bSMingming Cao * ext4_force_commit will write the file data into the journal and 145ac27a0ecSDave Kleikamp * will wait on that. 146ac27a0ecSDave Kleikamp * filemap_fdatawait() will encounter a ton of newly-dirtied pages 147ac27a0ecSDave Kleikamp * (they were dirtied by commit). But that's OK - the blocks are 148ac27a0ecSDave Kleikamp * safe in-journal, which is all fsync() needs to ensure. 149ac27a0ecSDave Kleikamp */ 1500562e0baSJiaying Zhang if (ext4_should_journal_data(inode)) { 1510562e0baSJiaying Zhang ret = ext4_force_commit(inode->i_sb); 1520562e0baSJiaying Zhang goto out; 1530562e0baSJiaying Zhang } 154ac27a0ecSDave Kleikamp 155b436b9beSJan Kara commit_tid = datasync ? ei->i_datasync_tid : ei->i_sync_tid; 15693628ffbSJan Kara if (journal->j_flags & JBD2_BARRIER && 15793628ffbSJan Kara !jbd2_trans_will_send_data_barrier(journal, commit_tid)) 15893628ffbSJan Kara needs_barrier = true; 159d76a3a77STheodore Ts'o ret = jbd2_complete_transaction(journal, commit_tid); 160a4a39040STheodore Ts'o if (needs_barrier) { 16178d96251STheodore Ts'o issue_flush: 162a4a39040STheodore Ts'o err = blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL); 163a4a39040STheodore Ts'o if (!ret) 164a4a39040STheodore Ts'o ret = err; 165a4a39040STheodore Ts'o } 1660562e0baSJiaying Zhang out: 16795cb6713STheodore Ts'o err = file_check_and_advance_wb_err(file); 16895cb6713STheodore Ts'o if (ret == 0) 16995cb6713STheodore Ts'o ret = err; 1700562e0baSJiaying Zhang trace_ext4_sync_file_exit(inode, ret); 171ac27a0ecSDave Kleikamp return ret; 172ac27a0ecSDave Kleikamp } 173