Zsh Mailing List Archive
Messages sorted by:
Reverse Date,
Date,
Thread,
Author
Re: No fsync on history file? I lost my history
- X-seq: zsh-users 23674
- From: lilydjwg <lilydjwg@xxxxxxxxx>
- To: Daniel Shahaf <d.s@xxxxxxxxxxxxxxxxxx>
- Subject: Re: No fsync on history file? I lost my history
- Date: Sun, 23 Sep 2018 23:25:46 +0800
- Cc: zsh-users@xxxxxxx
- Disposition-notification-to: lilydjwg@xxxxxxxxx
- Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:disposition-notification-to :user-agent; bh=2g/g89XxWV5B81heDDVb3gvWPC3fQla2QUUAkz8vPN0=; b=G/+vKlSwt3hF6VhkO7I6+4D3LmjcMLV+3J6dVK7HVj9Jf1oHN6dJDa/e+NaGnJ11hd KcHjCWayxMAsq+rJeFGkF/ntx/7w/N9ZFI69eQC1i4vdXSxqS+gpAkM1FNDpAl+Tab3y vxCzRZM7zFGsi8EomLrjblzgkEX4aQH3RdgJark/lqWYSDlzemanYLuNt6/kxsyTnUr4 4fykMhET9g62rfqRPpiCTSYQAOJGK3rDTYEQvlr2v4tXNBryJYqD60RL37ZBvGyx3Hwi DxlDV1XEsb9Qu6pVeh+qgYfMpqZXfUdAqJ/pQPuUWUPBqAPM1F1D8HMEyLg+ldPbSRMJ 8IUw==
- In-reply-to: <1537714011.118073.1517716184.0B2E8824@webmail.messagingengine.com>
- List-help: <mailto:zsh-users-help@zsh.org>
- List-id: Zsh Users List <zsh-users.zsh.org>
- List-post: <mailto:zsh-users@zsh.org>
- List-unsubscribe: <mailto:zsh-users-unsubscribe@zsh.org>
- Mailing-list: contact zsh-users-help@xxxxxxx; run by ezmlm
- References: <20180923085246.GA19251@lilyforest.localdomain> <1537709747.103981.1517680056.72C7A43E@webmail.messagingengine.com> <20180923142255.GA4931@lilyforest.localdomain> <1537714011.118073.1517716184.0B2E8824@webmail.messagingengine.com>
I'm sending an updated patch.
On Sun, Sep 23, 2018 at 02:46:51PM +0000, Daniel Shahaf wrote:
> fsync() is in POSIX. I assume we can just call it, but if somebody complains
> we'll need to use an HAVE_FSYNC guard.
I don't know how to add a HAVE_FSYNC macro to the build system, sorry.
> > +++ b/Src/hist.c
> > @@ -2933,6 +2933,9 @@ savehistfile(char *fn, int err, int writeflags)
> > lasthist.text = ztrdup(start);
> > }
> > }
> > + fflush(out); /* need to flush before fsync */
>
> Isn't the fflush() on line 2927 sufficient? (Even if it isn't, I would have
> expected a ret>=0 guard around this call.)
It should call write(2) to write out the buffered data. Then the kernel
can fsync the data to disk. A guard has been added.
> > + if (fsync(fileno(out)) < 0 && ret >= 0)
> > + ret = -1;
>
> fileno() can return -1.
It shouldn't matter, fsync will return EBADF for -1. Other parts of the
code don't check for this either, and I can't think a case when fileno
would fail after so many successful I/O operations on it (corrupted memory?)
> Shouldn't the ret>=0 check happen before the calls to fileno() and fsync()?
Yes, I've changed that.
--
Best regards,
lilydjwg
From 3c6c07733f12176c737d1f610f0dceafd07437df Mon Sep 17 00:00:00 2001
From: lilydjwg <lilydjwg@xxxxxxxxx>
Date: Sun, 23 Sep 2018 22:12:56 +0800
Subject: [PATCH] Call fsync after writing out new histfile
to ensure the data is on disk before the rename in case of a system crash.
---
Src/hist.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/Src/hist.c b/Src/hist.c
index dbdc1e4e5..d3370252d 100644
--- a/Src/hist.c
+++ b/Src/hist.c
@@ -2933,6 +2933,10 @@ savehistfile(char *fn, int err, int writeflags)
lasthist.text = ztrdup(start);
}
}
+ if (ret >= 0)
+ ret = fflush(out); /* need to flush before fsync */
+ if (ret >= 0 && fsync(fileno(out)) < 0)
+ ret = -1;
if (fclose(out) < 0 && ret >= 0)
ret = -1;
if (ret >= 0) {
--
2.19.0
Messages sorted by:
Reverse Date,
Date,
Thread,
Author