Removed an unnecessary return statement at the end of xen_gnttab_free_callback(), which has the return type void.

Fixed xbd_max_request_segments being incorrectly set to 0

Ping

Ping.

Thoughts on changing the condition mentioned in the previous comment to a KASSERT?

Committed by Roger as rS334205

Committed by Roger as rS336895

Committed by Roger as rS336896

Before you commit this, I just noticed that gnttab_free_grant_references() does

if (head == GNTTAB_LIST_END)
	return;

Turned the check into a KASSERT.

Probably a difference in the tab width. I don't get why there is indentation with both tabs and spaces in a single line. The entire blkfront code is like that. Some places its all tabs, some places it is a mix of tabs and spaces for indentation. Its weird and confusing.

Ping.

Updated the diff to add flag M_NOWAIT to the contigmalloc() used to allocate the indirection pages. Also, added a NULL check there in case contigmalloc fails.

The contigmalloc(9) man page says only 2 flags can be used: M_NOWAIT and M_ZERO. All other flags (if present) will be ignored. So M_WAITOK can not be used.

I asked on freebsd-hackers@ mailing list, and Conrad Meyer says that contigmalloc() can fail even when M_NOWAIT is not specified. Link to the email.

Removed the NULL check.

I updated the diff. Your call if you want to commit the change or leave it as it is.

Any comments?