We need to flush the write cache unconditionally in ->fsync, otherwise writes into already allocated blocks can get lost. Writes into fully allocated files are very common when using disk images for virtualization, and without this fix can easily lose data after an fdatasync, which is the typical implementation for a cache flush on the virtual drive. Signed-off-by: Christoph Hellwig <hch@xxxxxx> Index: linux-2.6/fs/ext4/fsync.c =================================================================== --- linux-2.6.orig/fs/ext4/fsync.c +++ linux-2.6/fs/ext4/fsync.c @@ -92,9 +92,9 @@ int ext4_sync_file(struct file *file, st .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); } out: + if (journal && (journal->j_flags & JBD2_BARRIER)) + blkdev_issue_flush(inode->i_sb->s_bdev, NULL); return ret; } -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
