Messages in this thread Patch in this message | | | Subject | ext4: call blkdev_issue_flush on fsync | From | Fernando Luis Vázquez Cao <> | Date | Fri, 16 Jan 2009 22:59:44 +0900 |
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To ensure that bits are truly on-disk after an fsync or fdatasync, we should force a disk flush explicitly when there is dirty data/metadata and the journal didn't emit a write barrier (either because metadata is not being synched or barriers are disabled).
Signed-off-by: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp> ---
--- linux-2.6.29-rc1-orig/fs/ext4/fsync.c 2008-12-25 08:26:37.000000000 +0900 +++ linux-2.6.29-rc1/fs/ext4/fsync.c 2009-01-16 22:18:51.000000000 +0900 @@ -48,6 +48,7 @@ int ext4_sync_file(struct file *file, st { struct inode *inode = dentry->d_inode; journal_t *journal = EXT4_SB(inode->i_sb)->s_journal; + unsigned long i_state = inode->i_state; int ret = 0; J_ASSERT(ext4_journal_current_handle() == NULL); @@ -76,25 +77,33 @@ int ext4_sync_file(struct file *file, st */ if (ext4_should_journal_data(inode)) { ret = ext4_force_commit(inode->i_sb); + if (!(journal->j_flags & JBD2_BARRIER)) + goto no_journal_barrier; goto out; } - if (datasync && !(inode->i_state & I_DIRTY_DATASYNC)) - goto out; + if (datasync && !(i_state & I_DIRTY_DATASYNC)) + goto flush_blkdev; /* * The VFS has written the file data. If the inode is unaltered * then we need not start a commit. */ - if (inode->i_state & (I_DIRTY_SYNC|I_DIRTY_DATASYNC)) { + if (i_state & (I_DIRTY_SYNC|I_DIRTY_DATASYNC)) { struct writeback_control wbc = { .sync_mode = WB_SYNC_ALL, .nr_to_write = 0, /* sys_fsync did this */ }; ret = sync_inode(inode, &wbc); - if (journal && (journal->j_flags & JBD2_BARRIER)) - blkdev_issue_flush(inode->i_sb->s_bdev, NULL); + if (journal && !(journal->j_flags & JBD2_BARRIER)) + goto no_journal_barrier; } + +flush_blkdev: + if (!(i_state & I_DIRTY_PAGES)) + goto out; +no_journal_barrier: + blkdev_issue_flush(inode->i_sb->s_bdev, NULL); out: return ret; }
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