Something went wrong. Try again.
Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Something went wrong. Try again.
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191// SPDX-License-Identifier: GPL-2.0/* * linux/fs/ext4/fsync.c * * Copyright (C) 1993 Stephen Tweedie (sct@redhat.com) * from * Copyright (C) 1992 Remy Card (card@masi.ibp.fr) * Laboratoire MASI - Institut Blaise Pascal * Universite Pierre et Marie Curie (Paris VI) * from * linux/fs/minix/truncate.c Copyright (C) 1991, 1992 Linus Torvalds * * ext4fs fsync primitive * * Big-endian to little-endian byte-swapping/bitmaps by * David S. Miller (davem@caip.rutgers.edu), 1995 * * Removed unnecessary code duplication for little endian machines * and excessive __inline__s. * Andi Kleen, 1997 * * Major simplications and cleanup - we only need to do the metadata, because * we can depend on generic_block_fdatasync() to sync the data blocks. */
#include <linux/time.h>#include <linux/fs.h>#include <linux/sched.h>#include <linux/writeback.h>#include <linux/blkdev.h>#include <linux/buffer_head.h>
#include "ext4.h"#include "ext4_jbd2.h"
#include <trace/events/ext4.h>
/* * If we're not journaling and this is a just-created file, we have to * sync our parent directory (if it was freshly created) since * otherwise it will only be written by writeback, leaving a huge * window during which a crash may lose the file. This may apply for * the parent directory's parent as well, and so on recursively, if * they are also freshly created. */static int ext4_sync_parent(struct inode *inode){ struct dentry *dentry, *next; int ret = 0;
if (!ext4_test_inode_state(inode, EXT4_STATE_NEWENTRY)) return 0; dentry = d_find_any_alias(inode); if (!dentry) return 0; while (ext4_test_inode_state(inode, EXT4_STATE_NEWENTRY)) { ext4_clear_inode_state(inode, EXT4_STATE_NEWENTRY);
next = dget_parent(dentry); dput(dentry); dentry = next; inode = dentry->d_inode;
/* * The directory inode may have gone through rmdir by now. But * the inode itself and its blocks are still allocated (we hold * a reference to the inode via its dentry), so it didn't go * through ext4_evict_inode()) and so we are safe to flush * metadata blocks and the inode. */ ret = mmb_sync(&EXT4_I(inode)->i_metadata_bhs); if (ret) break; ret = sync_inode_metadata(inode, 1); if (ret) break; } dput(dentry); return ret;}
static int ext4_fsync_nojournal(struct file *file, loff_t start, loff_t end, int datasync, bool *needs_barrier){ struct inode *inode = file->f_inode; struct writeback_control wbc = { .sync_mode = WB_SYNC_ALL, .nr_to_write = 0, }; int ret;
ret = mmb_fsync_noflush(file, &EXT4_I(inode)->i_metadata_bhs, start, end, datasync); if (ret) return ret;
/* Force writeout of inode table buffer to disk */ ret = ext4_write_inode(inode, &wbc); if (ret) return ret;
ret = ext4_sync_parent(inode);
if (test_opt(inode->i_sb, BARRIER)) *needs_barrier = true;
return ret;}
static int ext4_fsync_journal(struct inode *inode, bool datasync, bool *needs_barrier){ struct ext4_inode_info *ei = EXT4_I(inode); journal_t *journal = EXT4_SB(inode->i_sb)->s_journal; tid_t commit_tid = datasync ? ei->i_datasync_tid : ei->i_sync_tid;
/* * Fastcommit does not really support fsync on directories or other * special files. Force a full commit. */ if (!S_ISREG(inode->i_mode)) return ext4_force_commit(inode->i_sb);
if (journal->j_flags & JBD2_BARRIER && !jbd2_trans_will_send_data_barrier(journal, commit_tid)) *needs_barrier = true;
return ext4_fc_commit(journal, commit_tid);}
/* * akpm: A new design for ext4_sync_file(). * * This is only called from sys_fsync(), sys_fdatasync() and sys_msync(). * There cannot be a transaction open by this task. * Another task could have dirtied this inode. Its data can be in any * state in the journalling system. * * What we do is just kick off a commit and wait on it. This will snapshot the * inode to disk. */int ext4_sync_file(struct file *file, loff_t start, loff_t end, int datasync){ int ret = 0, err; bool needs_barrier = false; struct inode *inode = file->f_mapping->host;
ret = ext4_emergency_state(inode->i_sb); if (unlikely(ret)) return ret;
ASSERT(ext4_journal_current_handle() == NULL);
trace_ext4_sync_file_enter(file, datasync);
if (sb_rdonly(inode->i_sb)) goto out;
if (!EXT4_SB(inode->i_sb)->s_journal) { ret = ext4_fsync_nojournal(file, start, end, datasync, &needs_barrier); if (needs_barrier) goto issue_flush; goto out; }
ret = file_write_and_wait_range(file, start, end); if (ret) goto out;
/* * The caller's filemap_fdatawrite()/wait will sync the data. * Metadata is in the journal, we wait for proper transaction to * commit here. */ ret = ext4_fsync_journal(inode, datasync, &needs_barrier);
issue_flush: if (needs_barrier) { err = blkdev_issue_flush(inode->i_sb->s_bdev); if (!ret) ret = err; }out: err = file_check_and_advance_wb_err(file); if (ret == 0) ret = err; trace_ext4_sync_file_exit(inode, ret); return ret;}