Re: True ACID under linux (no fsync)?

On 31 Oct 2000, Gary Howland wrote:

> Just a quickie - I heard that linux does not have a working fsync() call

At least the manpage for fsync says that it does.

The implementation:

/* .. finally sync the buffers to disk */
dev = inode->i_dev;
return sync_buffers(dev, 1);

It really looks like it IS implemented. But probably on Linux not just the
file data/metadata is synced, also all that device's data, which makes it
very inefficient, but presumably `safe'.

NB: don't forget that fsync() merely ensures that data was sent to the
disk controller. Maybe this one has a cache (e.g. a fast SCSI harddrive),
and if power fails, well. If fsync() was calling the SCSI FLUSH command,
maybe that could be done, but that would not just sync the file.