mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Andrey Savochkin <saw@saw.sw.com.sg>
To: linux-kernel@vger.kernel.org
Subject: Q about pagecache data never written to disk
Date: Sun, 5 Sep 2004 12:01:47 +0400	[thread overview]
Message-ID: <20040905120147.A9202@castle.nmd.msu.ru> (raw)

Let's suppose an mmap'ed (SHARED, RW) file has a hole.
AFAICS, we allow to dirty the file pages without allocating the space for the
hole - filemap_nopage just "reads" the page filling it with zeroes, and
nothing is done about the on-disk data until writepage.

So, if the page can't be written to disk (no space), the dirty data just
stays in the pagecache.  The data can be read or seen via mmap, but it isn't
and never be on disk.  The pagecache stays unsynchronized with the on-disk
content forever.

Is it the intended behavior?
Shouldn't we call the filesystem to fill the hole at the moment of the first
write access?

	Andrey

             reply	other threads:[~2004-09-05  8:01 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-09-05  8:01 Andrey Savochkin [this message]
2004-09-05  9:22 ` William Lee Irwin III
2004-09-05 10:52 ` Andrew Morton
2004-09-05 11:43   ` Andrey Savochkin
2004-09-05 21:00     ` Andrew Morton
2004-09-06  7:06       ` Andrey Savochkin
2004-09-09 12:39       ` Pavel Machek
2004-09-09 13:15         ` Nick Piggin
2004-09-09 13:37           ` Pavel Machek
2004-09-09 13:32             ` Nick Piggin
2004-09-09 17:24               ` William Lee Irwin III
2004-09-09 17:14                 ` Nick Piggin
2004-09-09 17:35                   ` William Lee Irwin III
2004-09-05 16:33   ` William Lee Irwin III
2004-09-06  6:24     ` William Lee Irwin III
2004-09-06  7:02       ` Andrew Morton
2004-09-06 15:12         ` William Lee Irwin III

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20040905120147.A9202@castle.nmd.msu.ru \
    --to=saw@saw.sw.com.sg \
    --cc=linux-kernel@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox

all inboxes | Powered by JetHome®