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 { 4708adf452SEric Biggers struct dentry *dentry, *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; 529f713878SAl Viro dentry = d_find_any_alias(inode); 53d59729f4STheodore Ts'o if (!dentry) 5408adf452SEric Biggers return 0; 5508adf452SEric Biggers while (ext4_test_inode_state(inode, EXT4_STATE_NEWENTRY)) { 5608adf452SEric Biggers ext4_clear_inode_state(inode, EXT4_STATE_NEWENTRY); 5708adf452SEric Biggers 5808adf452SEric Biggers next = dget_parent(dentry); 59d59729f4STheodore Ts'o dput(dentry); 6008adf452SEric Biggers dentry = next; 6108adf452SEric Biggers inode = dentry->d_inode; 6208adf452SEric Biggers 636ae4c5a6SJan Kara /* 646ae4c5a6SJan Kara * The directory inode may have gone through rmdir by now. But 656ae4c5a6SJan Kara * the inode itself and its blocks are still allocated (we hold 6608adf452SEric Biggers * a reference to the inode via its dentry), so it didn't go 6708adf452SEric Biggers * through ext4_evict_inode()) and so we are safe to flush 6808adf452SEric Biggers * metadata blocks and the inode. 696ae4c5a6SJan Kara */ 700893ed45SCurt Wohlgemuth ret = sync_mapping_buffers(inode->i_mapping); 710893ed45SCurt Wohlgemuth if (ret) 720893ed45SCurt Wohlgemuth break; 7364744e03SGuo Chao ret = sync_inode_metadata(inode, 1); 740893ed45SCurt Wohlgemuth if (ret) 750893ed45SCurt Wohlgemuth break; 7614ece102SFrank Mayhar } 7708adf452SEric Biggers dput(dentry); 780893ed45SCurt Wohlgemuth return ret; 7914ece102SFrank Mayhar } 8014ece102SFrank Mayhar 813eaf9cc6SMatthew Bobrowski static int ext4_fsync_nojournal(struct inode *inode, bool datasync, 823eaf9cc6SMatthew Bobrowski bool *needs_barrier) 833eaf9cc6SMatthew Bobrowski { 843eaf9cc6SMatthew Bobrowski int ret, err; 853eaf9cc6SMatthew Bobrowski 863eaf9cc6SMatthew Bobrowski ret = sync_mapping_buffers(inode->i_mapping); 873eaf9cc6SMatthew Bobrowski if (!(inode->i_state & I_DIRTY_ALL)) 883eaf9cc6SMatthew Bobrowski return ret; 893eaf9cc6SMatthew Bobrowski if (datasync && !(inode->i_state & I_DIRTY_DATASYNC)) 903eaf9cc6SMatthew Bobrowski return ret; 913eaf9cc6SMatthew Bobrowski 923eaf9cc6SMatthew Bobrowski err = sync_inode_metadata(inode, 1); 933eaf9cc6SMatthew Bobrowski if (!ret) 943eaf9cc6SMatthew Bobrowski ret = err; 953eaf9cc6SMatthew Bobrowski 963eaf9cc6SMatthew Bobrowski if (!ret) 973eaf9cc6SMatthew Bobrowski ret = ext4_sync_parent(inode); 983eaf9cc6SMatthew Bobrowski if (test_opt(inode->i_sb, BARRIER)) 993eaf9cc6SMatthew Bobrowski *needs_barrier = true; 1003eaf9cc6SMatthew Bobrowski 1013eaf9cc6SMatthew Bobrowski return ret; 1023eaf9cc6SMatthew Bobrowski } 1033eaf9cc6SMatthew Bobrowski 1043eaf9cc6SMatthew Bobrowski static int ext4_fsync_journal(struct inode *inode, bool datasync, 1053eaf9cc6SMatthew Bobrowski bool *needs_barrier) 1063eaf9cc6SMatthew Bobrowski { 1073eaf9cc6SMatthew Bobrowski struct ext4_inode_info *ei = EXT4_I(inode); 1083eaf9cc6SMatthew Bobrowski journal_t *journal = EXT4_SB(inode->i_sb)->s_journal; 1093eaf9cc6SMatthew Bobrowski tid_t commit_tid = datasync ? ei->i_datasync_tid : ei->i_sync_tid; 1103eaf9cc6SMatthew Bobrowski 1113eaf9cc6SMatthew Bobrowski if (journal->j_flags & JBD2_BARRIER && 1123eaf9cc6SMatthew Bobrowski !jbd2_trans_will_send_data_barrier(journal, commit_tid)) 1133eaf9cc6SMatthew Bobrowski *needs_barrier = true; 1143eaf9cc6SMatthew Bobrowski 1153eaf9cc6SMatthew Bobrowski return jbd2_complete_transaction(journal, commit_tid); 1163eaf9cc6SMatthew Bobrowski } 1173eaf9cc6SMatthew Bobrowski 11814ece102SFrank Mayhar /* 119617ba13bSMingming Cao * akpm: A new design for ext4_sync_file(). 120ac27a0ecSDave Kleikamp * 121ac27a0ecSDave Kleikamp * This is only called from sys_fsync(), sys_fdatasync() and sys_msync(). 122ac27a0ecSDave Kleikamp * There cannot be a transaction open by this task. 123ac27a0ecSDave Kleikamp * Another task could have dirtied this inode. Its data can be in any 124ac27a0ecSDave Kleikamp * state in the journalling system. 125ac27a0ecSDave Kleikamp * 126ac27a0ecSDave Kleikamp * What we do is just kick off a commit and wait on it. This will snapshot the 127ac27a0ecSDave Kleikamp * inode to disk. 128ac27a0ecSDave Kleikamp */ 12902c24a82SJosef Bacik int ext4_sync_file(struct file *file, loff_t start, loff_t end, int datasync) 130ac27a0ecSDave Kleikamp { 13137b10dd0SJan Kara int ret = 0, err; 13293628ffbSJan Kara bool needs_barrier = false; 1333eaf9cc6SMatthew Bobrowski struct inode *inode = file->f_mapping->host; 1343eaf9cc6SMatthew Bobrowski struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 135ac27a0ecSDave Kleikamp 1363eaf9cc6SMatthew Bobrowski if (unlikely(ext4_forced_shutdown(sbi))) 1370db1ff22STheodore Ts'o return -EIO; 1380db1ff22STheodore Ts'o 139ac39849dSAneesh Kumar K.V J_ASSERT(ext4_journal_current_handle() == NULL); 140ac27a0ecSDave Kleikamp 1410562e0baSJiaying Zhang trace_ext4_sync_file_enter(file, datasync); 142ede86cc4STheodore Ts'o 143bc98a42cSDavid Howells if (sb_rdonly(inode->i_sb)) { 1444418e141SDmitry Monakhov /* Make sure that we read updated s_mount_flags value */ 1454418e141SDmitry Monakhov smp_rmb(); 1463eaf9cc6SMatthew Bobrowski if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) 1474418e141SDmitry Monakhov ret = -EROFS; 14892e6222dSJan Kara goto out; 1494418e141SDmitry Monakhov } 15037b10dd0SJan Kara 1518fdd60f2STheodore Ts'o ret = file_write_and_wait_range(file, start, end); 1528fdd60f2STheodore Ts'o if (ret) 1532be7d717SZhang Qilong goto out; 1543eaf9cc6SMatthew Bobrowski 155ac27a0ecSDave Kleikamp /* 156b436b9beSJan Kara * data=writeback,ordered: 157ac27a0ecSDave Kleikamp * The caller's filemap_fdatawrite()/wait will sync the data. 158b436b9beSJan Kara * Metadata is in the journal, we wait for proper transaction to 159b436b9beSJan Kara * commit here. 160ac27a0ecSDave Kleikamp * 161ac27a0ecSDave Kleikamp * data=journal: 162ac27a0ecSDave Kleikamp * filemap_fdatawrite won't do anything (the buffers are clean). 163617ba13bSMingming Cao * ext4_force_commit will write the file data into the journal and 164ac27a0ecSDave Kleikamp * will wait on that. 165ac27a0ecSDave Kleikamp * filemap_fdatawait() will encounter a ton of newly-dirtied pages 166ac27a0ecSDave Kleikamp * (they were dirtied by commit). But that's OK - the blocks are 167ac27a0ecSDave Kleikamp * safe in-journal, which is all fsync() needs to ensure. 168ac27a0ecSDave Kleikamp */ 1693eaf9cc6SMatthew Bobrowski if (!sbi->s_journal) 1703eaf9cc6SMatthew Bobrowski ret = ext4_fsync_nojournal(inode, datasync, &needs_barrier); 1713eaf9cc6SMatthew Bobrowski else if (ext4_should_journal_data(inode)) 1720562e0baSJiaying Zhang ret = ext4_force_commit(inode->i_sb); 1733eaf9cc6SMatthew Bobrowski else 1743eaf9cc6SMatthew Bobrowski ret = ext4_fsync_journal(inode, datasync, &needs_barrier); 175ac27a0ecSDave Kleikamp 176a4a39040STheodore Ts'o if (needs_barrier) { 1779398554fSChristoph Hellwig err = blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL); 178a4a39040STheodore Ts'o if (!ret) 179a4a39040STheodore Ts'o ret = err; 180a4a39040STheodore Ts'o } 1810562e0baSJiaying Zhang out: 18295cb6713STheodore Ts'o err = file_check_and_advance_wb_err(file); 18395cb6713STheodore Ts'o if (ret == 0) 18495cb6713STheodore Ts'o ret = err; 1850562e0baSJiaying Zhang trace_ext4_sync_file_exit(inode, ret); 186ac27a0ecSDave Kleikamp return ret; 187ac27a0ecSDave Kleikamp } 188