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List: kde-frameworks-devel
Subject: Re: Review Request 129259: Fix the buffersize in certain situations.
From: Jonathan Doman <jonathan.doman () gmail ! com>
Date: 2016-10-26 19:54:47
Message-ID: 20161026195447.9507.60419 () mimi ! kde ! org
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> On Oct. 26, 2016, 9:48 a.m., Andreas Hartmetz wrote:
> > If a workaround was really necessary I'd agree with Jonathan. But it looks like a \
> > workaround to fix up st_size is not necessary, because both Krusader and ls (just \
> > two examples I could easily find) work without changing st_size. Note that they \
> > use a different way to check whether the current file is a symlink, not sure if \
> > that makes the difference though. \
> > https://quickgit.kde.org/?p=krusader.git&a=blob&h=932340774d439b1ea770204903c1f8c4 \
> > 31dc86db&hb=f1660b241d195a31a904a1706fb8022b99e4c709&f=krusader%2FVFS%2Fnormal_vfs.cpp
> > http://git.savannah.gnu.org/cgit/coreutils.git/tree/src/ls.c
Actually, take a look at the readlink implementation that ls calls: \
http://git.savannah.gnu.org/gitweb/?p=gnulib.git;a=blob;f=lib/areadlink-with-size.c;hb=HEAD
It does almost exactly what is proposed by this review, for the same reasons ("Some \
buggy file systems report garbage in st_size").
- Jonathan
-----------------------------------------------------------
This is an automatically generated e-mail. To reply, visit:
https://git.reviewboard.kde.org/r/129259/#review100304
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On Oct. 25, 2016, 9:51 a.m., taro yamada wrote:
>
> -----------------------------------------------------------
> This is an automatically generated e-mail. To reply, visit:
> https://git.reviewboard.kde.org/r/129259/
> -----------------------------------------------------------
>
> (Updated Oct. 25, 2016, 9:51 a.m.)
>
>
> Review request for KDE Frameworks.
>
>
> Bugs: 369275
> https://bugs.kde.org/show_bug.cgi?id=369275
>
>
> Repository: kio
>
>
> Description
> -------
>
> Currently, KIO uses lstat to get the buffersize for readlink.
> But in certain situations, it returns inappropriate value.
>
> For example, "/proc/self" or "/sys/bus/cpu/devices/*" returns its size is 0 , and \
> then readlink fails with EINVAL.(so link won't be shown in kde application.) TMSU \
> seems it returns its target's actual filesize insted of the link's filesize itself. \
> This patch changes the buffersize to 1024 bytes if it is 0.
> And later truncate it to actual size.
>
>
> Diffs
> -----
>
> src/ioslaves/file/file.cpp 8b17d31
>
> Diff: https://git.reviewboard.kde.org/r/129259/diff/
>
>
> Testing
> -------
>
>
> Thanks,
>
> taro yamada
>
>
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This is an automatically generated e-mail. To reply, visit:
<a href="https://git.reviewboard.kde.org/r/129259/">https://git.reviewboard.kde.org/r/129259/</a>
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<br />
<blockquote style="margin-left: 1em; border-left: 2px solid #d0d0d0; padding-left: \
10px;"> <p style="margin-top: 0;">On October 26th, 2016, 9:48 a.m. CDT, <b>Andreas \
Hartmetz</b> wrote:</p> <blockquote style="margin-left: 1em; border-left: 2px solid \
#d0d0d0; padding-left: 10px;"> <pre style="white-space: pre-wrap; white-space: \
-moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: \
break-word;"><p style="padding: 0;text-rendering: inherit;margin: 0;line-height: \
inherit;white-space: inherit;">If a workaround was really necessary I'd agree with \
Jonathan. But it looks like a workaround to fix up st_size is not necessary, because \
both Krusader and ls (just two examples I could easily find) work without changing \
st_size. Note that they use a different way to check whether the current file is a \
symlink, not sure if that makes the difference though. \
https://quickgit.kde.org/?p=krusader.git&a=blob&h=932340774d439b1ea770204903c1 \
f8c431dc86db&hb=f1660b241d195a31a904a1706fb8022b99e4c709&f=krusader%2FVFS%2Fnormal_vfs.cpp
http://git.savannah.gnu.org/cgit/coreutils.git/tree/src/ls.c</p></pre>
</blockquote>
</blockquote>
<pre style="white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: \
-pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;"><p style="padding: \
0;text-rendering: inherit;margin: 0;line-height: inherit;white-space: \
inherit;">Actually, take a look at the readlink implementation that ls calls: \
http://git.savannah.gnu.org/gitweb/?p=gnulib.git;a=blob;f=lib/areadlink-with-size.c;hb=HEAD</p>
<p style="padding: 0;text-rendering: inherit;margin: 0;line-height: \
inherit;white-space: inherit;">It does almost exactly what is proposed by this \
review, for the same reasons ("Some buggy file systems report garbage in \
st_size").</p></pre> <br />
<p>- Jonathan</p>
<br />
<p>On October 25th, 2016, 9:51 a.m. CDT, taro yamada wrote:</p>
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<div>Review request for KDE Frameworks.</div>
<div>By taro yamada.</div>
<p style="color: grey;"><i>Updated Oct. 25, 2016, 9:51 a.m.</i></p>
<div style="margin-top: 1.5em;">
<b style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Bugs: </b>
<a href="https://bugs.kde.org/show_bug.cgi?id=369275">369275</a>
</div>
<div style="margin-top: 1.5em;">
<b style="color: #575012; font-size: 10pt;">Repository: </b>
kio
</div>
<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Description </h1>
<table width="100%" bgcolor="#ffffff" cellspacing="0" cellpadding="10" \
style="border: 1px solid #b8b5a0"> <tr>
<td>
<pre style="margin: 0; padding: 0; white-space: pre-wrap; white-space: \
-moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: \
break-word;"><p style="padding: 0;text-rendering: inherit;margin: 0;line-height: \
inherit;white-space: inherit;">Currently, KIO uses lstat to get the buffersize for \
readlink. But in certain situations, it returns inappropriate value.</p>
<p style="padding: 0;text-rendering: inherit;margin: 0;line-height: \
inherit;white-space: inherit;">For example, "/proc/self" or "/sys/bus/cpu/devices/*" \
returns its size is 0 , and then readlink fails with EINVAL.(so link won't be shown \
in kde application.) TMSU seems it returns its target's actual filesize insted of the \
link's filesize itself.</p> <p style="padding: 0;text-rendering: inherit;margin: \
0;line-height: inherit;white-space: inherit;">This patch changes the buffersize to \
1024 bytes if it is 0. And later truncate it to actual size.</p></pre>
</td>
</tr>
</table>
<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Diffs</b> </h1>
<ul style="margin-left: 3em; padding-left: 0;">
<li>src/ioslaves/file/file.cpp <span style="color: grey">(8b17d31)</span></li>
</ul>
<p><a href="https://git.reviewboard.kde.org/r/129259/diff/" style="margin-left: \
3em;">View Diff</a></p>
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