On Mon, Jul 14, 2008 at 04:13:40PM -0600, Chris Torek wrote:
> The implementation of xfs_fsync() in 2.6.2x, for reasonably late x,
> reads as follows in xfs_vnodeops.c:
What kernel(s), exactly, is/are showing this problem?
> error = filemap_fdatawait(vn_to_inode(XFS_ITOV(ip))->i_mapping);
> We have a customer who is seeing data not "make it" to disk on a
> stress test that involves doing an fsync() or fdatasync() and then
> deliberately rebooting the machine (to simulate a failure; note
> that the underlying RAID has its own battery backup and this is
> just one of many different parts of the stress-test).
What is the symptom? The file size does not change? The file the
right size but has no data in it?
> Looking into this, I am now wondering if this call should read:
> error = filemap_write_and_wait(vn_to_inode(XFS_ITOV(ip))->i_mapping);
No, the filemap_fdatawrite() has already been executed by this
point. We only need to wait for I/O completion here. See do_fsync():
78 long do_fsync(struct file *file, int datasync)
90 ret = filemap_fdatawrite(mapping);
97 err = file->f_op->fsync(file, file->f_path.dentry, datasync);
The ->fsync() method in XFS is xfs_fsync()....
However, I do ask exactly what kernel version you are running,
because this mod that has gone into 2.6.26:
might be the fix you need for .24 or .25 kernels, (not sure about .22 or .23
where all this changed, nor .21 or earlier which I don't think even had the