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List:       yaffs
Subject:    Re: [Yaffs] a question about yaffs_hold_space
From:       Charles Manning <cdhmanning () gmail ! com>
Date:       2015-07-30 22:13:07
Message-ID: CAE21AQoKF=jY+nxUV_cYAEkhPKuc-zmX9xGJBb=0FT0Bxe6bTQ () mail ! gmail ! com
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The purpose of yaffs_hold_space() is to support the write_begin VFS method.

write_begin asks the file system to commit enough space to do the actual
write in write_end.

Strictly speaking this should really be handled with counter of committed
space that is incremented on every write_begin and decremented on every
write_end.

However, it is workable to just not expect there to be more than n writes
in progress at a time. n=20 seems rather conservative.

-- Charles


On Thu, Jul 30, 2015 at 3:04 PM, chenjie <chenjie6@huawei.com> wrote:

>
> Hi:
> why the yaffs_hold_space reserved 20 chunk?
>         return (n_free_chunks > 20) ? 1 : 0;
>
>
>
>

[Attachment #5 (text/html)]

<div dir="ltr"><div><div><div><div>The purpose of yaffs_hold_space() is to support \
the write_begin VFS method.<br><br></div>write_begin asks the file system to commit \
enough space to do the actual write in write_end.<br><br></div>Strictly speaking this \
should really be handled with counter of committed space that is incremented on every \
write_begin and decremented on every write_end.<br><br></div>However, it is workable \
to just not expect there to be more than n writes in progress at a time. n=20 seems \
rather conservative.<br><br></div>-- Charles<br><br></div><div \
class="gmail_extra"><br><div class="gmail_quote">On Thu, Jul 30, 2015 at 3:04 PM, \
chenjie <span dir="ltr">&lt;<a href="mailto:chenjie6@huawei.com" \
target="_blank">chenjie6@huawei.com</a>&gt;</span> wrote:<br><blockquote \
class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc \
solid;padding-left:1ex"><br> Hi:<br>
why the yaffs_hold_space reserved 20 chunk?<br>
            return (n_free_chunks &gt; 20) ? 1 : 0;<br>
<br>
<br>
<br>
</blockquote></div><br></div>



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