From: Paolo Bonzini <pbonzini@redhat.com>
To: Kevin Wolf <kwolf@redhat.com>
Cc: qemu-devel@nongnu.org, stefanha@linux.vnet.ibm.com
Subject: Re: [Qemu-devel] [PATCH 1.1 19/22] block: implement is_allocated for raw
Date: Wed, 09 May 2012 16:24:16 +0200 [thread overview]
Message-ID: <4FAA7E10.5020206@redhat.com> (raw)
In-Reply-To: <4FAA7AD2.3060308@redhat.com>
Il 09/05/2012 16:10, Kevin Wolf ha scritto:
> > While SEEK_* is not guaranteed by POSIX to be 0/1/2, the values is so
> > old that there may still exist programs that hard-code the values
> > (similar to O_RDONLY/O_WRONLY/O_RDWR, though probably not any other O_*
> > constant). It would be quite unwise to define them to something else.
> > Even MS-DOS reused the values!
> >
> > AFAIK this is the only extension of lseek that's ever been added. It
> > was done on Solaris first and then in Linux and the BSDs. It used 3/4
> > there too, see for example http://bugs.python.org/msg119551 (Solaris)
> > and http://mail-index.netbsd.org/tech-kern/2011/08/17/msg011231.html
> > (NetBSD).
>
> Why not simply #ifdef the whole code out and fall back to the current
> "everything is allocated" behaviour when SEEK_DATA/HOLE aren't defined?
That would be okay too of course.
When I wrote it Google Code existed still, so I must have taken the
idiom from some place. Now it doesn't anymore, so I cannot check and
it's okay to keep it safe. The code is a little bit uglier though.
Paolo
next prev parent reply other threads:[~2012-05-09 14:24 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-05-08 14:51 [Qemu-devel] [PATCH 1.1 00/22] Rebased queue of block patches Paolo Bonzini
2012-05-08 14:51 ` [Qemu-devel] [PATCH 1.1 01/22] block: fix snapshot on QED Paolo Bonzini
2012-05-09 12:15 ` Kevin Wolf
2012-05-08 14:51 ` [Qemu-devel] [PATCH 1.1 02/22] block: another bdrv_append fix Paolo Bonzini
2012-05-08 14:51 ` [Qemu-devel] [PATCH 1.1 03/22] block: do not reuse the backing file across bdrv_close/bdrv_open Paolo Bonzini
2012-05-08 14:51 ` [Qemu-devel] [PATCH 1.1 04/22] block: fully delete bs->file when closing Paolo Bonzini
2012-05-09 12:22 ` Kevin Wolf
2012-05-09 12:59 ` Paolo Bonzini
2012-05-08 14:51 ` [Qemu-devel] [PATCH 1.1 05/22] block: add block_job_sleep_ns Paolo Bonzini
2012-05-08 14:51 ` [Qemu-devel] [PATCH 1.1 06/22] block: wait for job callback in block_job_cancel_sync Paolo Bonzini
2012-05-08 14:51 ` [Qemu-devel] [PATCH 1.1 07/22] block: simplify path_is_absolute Paolo Bonzini
2012-05-08 14:51 ` [Qemu-devel] [PATCH 1.1 08/22] block: protect path_has_protocol from filenames with colons Paolo Bonzini
2012-05-08 14:51 ` [Qemu-devel] [PATCH 1.1 09/22] block: move field reset from bdrv_open_common to bdrv_close Paolo Bonzini
2012-05-08 14:51 ` [Qemu-devel] [PATCH 1.1 10/22] qemu-img: make "info" backing file output correct and easier to use Paolo Bonzini
2012-05-08 14:51 ` [Qemu-devel] [PATCH 1.1 11/22] qemu-io: correctly print non-integer values as decimals Paolo Bonzini
2012-05-09 12:46 ` Kevin Wolf
2012-05-09 12:48 ` Paolo Bonzini
2012-05-08 14:51 ` [Qemu-devel] [PATCH 1.1 12/22] qemu-io: fix the alloc command Paolo Bonzini
2012-05-08 14:51 ` [Qemu-devel] [PATCH 1.1 13/22] stream: fix sectors not allocated test Paolo Bonzini
2012-05-08 14:51 ` [Qemu-devel] [PATCH 1.1 14/22] stream: add testcase for partial streaming Paolo Bonzini
2012-05-09 12:59 ` Kevin Wolf
2012-05-09 13:05 ` [Qemu-devel] [PATCH 1.1 v2 " Paolo Bonzini
2012-05-08 14:51 ` [Qemu-devel] [PATCH 1.1 15/22] stream: pass new base image format to bdrv_change_backing_file Paolo Bonzini
2012-05-08 14:51 ` [Qemu-devel] [PATCH 1.1 16/22] stream: fix HMP block_job_set_speed Paolo Bonzini
2012-05-08 14:51 ` [Qemu-devel] [PATCH 1.1 17/22] stream: fix ratelimiting corner case Paolo Bonzini
2012-05-08 14:51 ` [Qemu-devel] [PATCH 1.1 18/22] stream: do not copy unallocated sectors from the base Paolo Bonzini
2012-05-08 14:51 ` [Qemu-devel] [PATCH 1.1 19/22] block: implement is_allocated for raw Paolo Bonzini
2012-05-09 13:40 ` Kevin Wolf
2012-05-09 14:05 ` Paolo Bonzini
2012-05-09 14:10 ` Kevin Wolf
2012-05-09 14:24 ` Paolo Bonzini [this message]
2012-05-09 14:49 ` [Qemu-devel] [PATCH next v2 " Paolo Bonzini
2012-05-08 14:52 ` [Qemu-devel] [PATCH 1.1 20/22] stream: tweak usage of bdrv_co_is_allocated Paolo Bonzini
2012-05-08 14:52 ` [Qemu-devel] [PATCH 1.1 21/22] stream: move is_allocated_above to block.c Paolo Bonzini
2012-05-08 14:52 ` [Qemu-devel] [PATCH 1.1 22/22] stream: move rate limiting to a separate header file Paolo Bonzini
2012-05-09 13:52 ` Kevin Wolf
2012-05-09 14:09 ` [Qemu-devel] [PATCH 1.1 v2 " Paolo Bonzini
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