Date: Sun, 2 Apr 2000 15:23:46 -0700 (PDT) From: Matthew Dillon <dillon@apollo.backplane.com> To: Poul-Henning Kamp <phk@FreeBSD.org> Cc: cvs-committers@FreeBSD.org, cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/kern subr_devstat.c src/sys/ufs/ufs ufs_disksubr.c src/sys/sys buf.h devicestat.h disklabel.h Message-ID: <200004022223.PAA51020@apollo.backplane.com> References: <200004021908.MAA17247@freefall.freebsd.org>
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:phk 2000/04/02 12:08:06 PDT
:
: Modified files:
: sys/kern subr_devstat.c
: sys/ufs/ufs ufs_disksubr.c
: sys/sys buf.h devicestat.h disklabel.h
: Log:
: Clone bio versions of certain bits of infrastructure:
: devstat_end_transaction_bio()
: bioq_* versions of bufq_* incl bioqdisksort()
: the corresponding "buf" versions will disappear when no longer used.
:
: Move b_offset, b_data and b_bcount to struct bio.
:
: Add BIO_FORMAT as a hack for fd.c etc.
:
: We are now largely ready to start converting drivers to use struct
: bio instead of struct buf.
b_data is integral to buffer cache KVA management & operation and
should be in the main struct buf structure, not the bio structure.
For example, at the moment device drivers that want to override b_data
must restore the original value prior to disposing of the buffer (this
was, in fact, one of the bugs in Greg's vinum code a few months
ago in his use of geteblk()).
b_bufsize is also integral to buffer cache management and should also
not be moved, just in case you are thinking of moving it.
This stuff should really be discussed before you make these sorts
of commits, you are getting perilously close to interfering with Kirk's
shared-lock work. It makes sense to isolate device-adjustable fields
in your struct bio, but it does not make sense to move buffer cache
management fields to the struct bio.
-Matt
Matthew Dillon
<dillon@backplane.com>
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