From: Christian Franke <Christian.Franke@t-online.de>
To: cygwin <cygwin@cygwin.com>
Subject: Re: Question about slow access to file information
Date: Sat, 14 Jan 2023 17:38:42 +0100 [thread overview]
Message-ID: <0c9c111e-9e63-bf8c-8049-06fd23f66351@t-online.de> (raw)
In-Reply-To: <797a8935-e38b-0c0f-87d8-b8df1e9fd76f@cs.umass.edu>
Eliot Moss via Cygwin wrote:
> I have a separate drive mounted this way:
>
> d:/ /cygdrive/d ntfs binary,posix=0,user,noacl,auto 0 0
>
> One thing I use it for is to store backup files. These tend to be 2 Gb
> chunks, and there can be hundreds of them in the backup directory.
> (The drive
> is 5Tb.) The Windows Disk Management tool describes it as NTFS, Basic
> Data
> Partition.
>
> Doing ls (for example) takes a very perceptible numbers of seconds
> (though
> whatever takes a long time seems to be cached, at least for a while,
> since a
> second ls soon after is fast).
The problem is the 'noacl' mount option and the fact that POSIX only
offers the *stat*() functions to retrieve file information. These
functions always need to provide the full file information, even if only
a small subset is needed.
To determine the 'x'-permission bits in the 'stat.st_mode' field on a
'noacl'-mount, Cygwin reads the first bytes of most files (all except
*.exe, *.lnk, *.com). The 'x' bits are set if the file starts with "#!"
(script), ":\n" (?) or "MZ" (Windows executable).
On 'noacl' mounts, this behavior could be suppressed by 'exec' or
'noexec' mount options.
--
Regards,
Christian
next prev parent reply other threads:[~2023-01-14 16:38 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-14 0:42 Eliot Moss
2023-01-14 13:45 ` Adam Dinwoodie
2023-01-14 16:38 ` Christian Franke [this message]
2023-01-15 1:05 ` Eliot Moss
2023-01-15 3:24 ` gs-cygwin.com
2023-01-17 15:21 ` Christian Franke
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=0c9c111e-9e63-bf8c-8049-06fd23f66351@t-online.de \
--to=christian.franke@t-online.de \
--cc=cygwin@cygwin.com \
/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;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).