From: Christoph Hellwig <hch-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>
To: Linus Torvalds
<torvalds-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>
Cc: Theodore Ts'o <tytso-3s7WtUTddSA@public.gmane.org>,
"Darrick J. Wong"
<darrick.wong-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>,
Jens Axboe <axboe-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org>,
Christoph Hellwig <hch-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>,
Andrew Morton
<akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>,
"Martin K. Petersen"
<martin.petersen-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>,
Linux API <linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
Linux Kernel Mailing List
<linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
shane.seymour-ZPxbGqLxI0U@public.gmane.org,
Bruce Fields <bfields-uC3wQj2KruNg9hUCZPvPmw@public.gmane.org>,
linux-fsdevel
<linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
Jeff Layton <jlayton-vpEMnDpepFuMZCB2o+C8xQ@public.gmane.org>
Subject: Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks
Date: Thu, 3 Mar 2016 10:00:03 -0800 [thread overview]
Message-ID: <20160303180003.GA6969@infradead.org> (raw)
In-Reply-To: <CA+55aFwPA1X8XGTdVZmP5uzkWMwj+X=bjkGVcEkZDme+qskrzQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
On Thu, Mar 03, 2016 at 09:55:38AM -0800, Linus Torvalds wrote:
> Ugh.
>
> But that essentially says that we shouldn't expose this interface at
> all (unless we trust our white-lists - I'm sure they are getting
> better, but if nobody has ever really _relied_ on the zeroing behavior
> of trim, then I guess there could be tons of bugs lurking).
Fortunately what Ted said is close to the truth, but a little off.
The mess about ATA is all real, and we work around it by never claiming
discard zeroes data for any ATA device except those specificly
whitelisted because the vendors gave guarantees for it (see the
ATA_HORKAGE_ZERO_AFTER_TRIM flag and the commit introducing it).
The reason why we don't use it unconditionally is simply because
there are users that want blocks zeroed without deallocating the
physical blocks. Now if you want to opt into the trim/unmap
behavior is one question, but we clearly need the split.
WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@infradead.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Theodore Ts'o <tytso@mit.edu>,
"Darrick J. Wong" <darrick.wong@oracle.com>,
Jens Axboe <axboe@kernel.dk>,
Christoph Hellwig <hch@infradead.org>,
Andrew Morton <akpm@linux-foundation.org>,
"Martin K. Petersen" <martin.petersen@oracle.com>,
Linux API <linux-api@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
shane.seymour@hpe.com, Bruce Fields <bfields@fieldses.org>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
Jeff Layton <jlayton@poochiereds.net>
Subject: Re: [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks
Date: Thu, 3 Mar 2016 10:00:03 -0800 [thread overview]
Message-ID: <20160303180003.GA6969@infradead.org> (raw)
In-Reply-To: <CA+55aFwPA1X8XGTdVZmP5uzkWMwj+X=bjkGVcEkZDme+qskrzQ@mail.gmail.com>
On Thu, Mar 03, 2016 at 09:55:38AM -0800, Linus Torvalds wrote:
> Ugh.
>
> But that essentially says that we shouldn't expose this interface at
> all (unless we trust our white-lists - I'm sure they are getting
> better, but if nobody has ever really _relied_ on the zeroing behavior
> of trim, then I guess there could be tons of bugs lurking).
Fortunately what Ted said is close to the truth, but a little off.
The mess about ATA is all real, and we work around it by never claiming
discard zeroes data for any ATA device except those specificly
whitelisted because the vendors gave guarantees for it (see the
ATA_HORKAGE_ZERO_AFTER_TRIM flag and the commit introducing it).
The reason why we don't use it unconditionally is simply because
there are users that want blocks zeroed without deallocating the
physical blocks. Now if you want to opt into the trim/unmap
behavior is one question, but we clearly need the split.
next prev parent reply other threads:[~2016-03-03 18:00 UTC|newest]
Thread overview: 135+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-02 4:09 [PATCH v5.1 0/2] create BLKZEROOUT ioctl that invalidates page cache Darrick J. Wong
2016-03-02 4:09 ` [PATCH 1/2] block: invalidate the page cache when issuing BLKZEROOUT Darrick J. Wong
2016-03-02 9:19 ` Christoph Hellwig
2016-03-02 4:09 ` [PATCH 2/2] block: create ioctl to discard-or-zeroout a range of blocks Darrick J. Wong
2016-03-02 9:20 ` Christoph Hellwig
[not found] ` <20160302040947.16685.42926.stgit-PTl6brltDGh4DFYR7WNSRA@public.gmane.org>
2016-03-02 18:52 ` Linus Torvalds
2016-03-02 18:52 ` Linus Torvalds
2016-03-02 22:56 ` Darrick J. Wong
2016-03-02 23:49 ` Linus Torvalds
2016-03-03 17:02 ` Theodore Ts'o
[not found] ` <20160303170205.GD24012-AKGzg7BKzIDYtjvyW6yDsg@public.gmane.org>
2016-03-03 17:55 ` Linus Torvalds
2016-03-03 17:55 ` Linus Torvalds
[not found] ` <CA+55aFwPA1X8XGTdVZmP5uzkWMwj+X=bjkGVcEkZDme+qskrzQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2016-03-03 18:00 ` Christoph Hellwig [this message]
2016-03-03 18:00 ` Christoph Hellwig
2016-03-03 18:14 ` Martin K. Petersen
2016-03-03 18:14 ` Martin K. Petersen
2016-03-03 18:21 ` Theodore Ts'o
2016-03-03 18:21 ` Theodore Ts'o
[not found] ` <CA+55aFyNPnjJ-Nsu3bMr+HuLQnkj1B8FMddNnXW7HJqxdUzJmQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2016-03-03 18:01 ` Martin K. Petersen
2016-03-03 18:01 ` Martin K. Petersen
[not found] ` <yq1bn6v8mqg.fsf-+q57XtR/GgMb6DWv4sQWN6xOck334EZe@public.gmane.org>
2016-03-03 18:09 ` Christoph Hellwig
2016-03-03 18:09 ` Christoph Hellwig
[not found] ` <20160303180924.GA4116-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>
2016-03-03 18:12 ` Darrick J. Wong
2016-03-03 18:12 ` Darrick J. Wong
2016-03-03 18:54 ` Martin K. Petersen
[not found] ` <yq1vb5375oh.fsf-+q57XtR/GgMb6DWv4sQWN6xOck334EZe@public.gmane.org>
2016-03-03 22:39 ` Theodore Ts'o
2016-03-03 22:39 ` Theodore Ts'o
[not found] ` <20160303223952.GE24012-AKGzg7BKzIDYtjvyW6yDsg@public.gmane.org>
2016-03-03 23:10 ` Dave Chinner
2016-03-03 23:10 ` Dave Chinner
2016-03-04 0:20 ` Theodore Ts'o
2016-03-04 0:20 ` Theodore Ts'o
2016-03-09 22:20 ` Gregory Farnum
2016-03-09 22:20 ` Gregory Farnum
2016-03-09 23:08 ` Theodore Ts'o
2016-03-10 14:58 ` Ric Wheeler
[not found] ` <56E18B9B.5070503-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2016-03-10 18:33 ` Linus Torvalds
2016-03-10 18:33 ` Linus Torvalds
[not found] ` <CA+55aFyw1nN4ze3-AGGE27evOZuXnkJC9C-W5QRUR=zKHqObGg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2016-03-10 21:47 ` Theodore Ts'o
2016-03-10 21:47 ` Theodore Ts'o
2016-03-11 4:42 ` Ric Wheeler
2016-03-11 13:59 ` One Thousand Gnomes
[not found] ` <20160311135952.57a44931-qBU/x9rampVanCEyBjwyrvXRex20P6io@public.gmane.org>
2016-03-11 15:27 ` Theodore Ts'o
2016-03-11 15:27 ` Theodore Ts'o
2016-03-11 17:23 ` Linus Torvalds
[not found] ` <CA+55aFwX2GYYN53E9qaTym=gp1aRjSA5f1G+N5WEiRd1dOJhFA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2016-03-11 17:30 ` Andy Lutomirski
2016-03-11 17:30 ` Andy Lutomirski
2016-03-11 18:25 ` Linus Torvalds
[not found] ` <CA+55aFxQOgDjL643J33d-3q7gYGvyN84vCn4qJq-Ox8E-WRx9w-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2016-03-11 22:30 ` Dave Chinner
2016-03-11 22:30 ` Dave Chinner
2016-03-12 0:33 ` Linus Torvalds
2016-03-12 0:33 ` Linus Torvalds
2016-03-12 0:35 ` Theodore Ts'o
2016-03-12 0:35 ` Theodore Ts'o
[not found] ` <20160312003556.GF32214-AKGzg7BKzIDYtjvyW6yDsg@public.gmane.org>
2016-03-12 0:44 ` Linus Torvalds
2016-03-12 0:44 ` Linus Torvalds
2016-03-12 7:19 ` Theodore Ts'o
[not found] ` <20160312071945.GA3419-AKGzg7BKzIDYtjvyW6yDsg@public.gmane.org>
2016-03-12 10:11 ` Thomas Schoebel-Theuer
2016-03-12 10:11 ` Thomas Schoebel-Theuer
2016-03-13 23:30 ` Dave Chinner
2016-03-13 23:30 ` Dave Chinner
2016-03-14 10:34 ` Ric Wheeler
2016-03-14 10:34 ` Ric Wheeler
[not found] ` <56E69398.7030508-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2016-03-14 14:46 ` Theodore Ts'o
2016-03-14 14:46 ` Theodore Ts'o
2016-03-15 20:14 ` Dave Chinner
2016-03-15 20:43 ` Linus Torvalds
2016-03-15 20:43 ` Linus Torvalds
[not found] ` <CA+55aFwHLJffmN-Dw=yZCGKzxe_2Tm9h2GjdaFL3JdvYXNstRw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2016-03-15 21:29 ` Theodore Ts'o
2016-03-15 21:29 ` Theodore Ts'o
2016-03-15 22:33 ` Dave Chinner
2016-03-15 22:33 ` Dave Chinner
2016-03-15 22:52 ` Theodore Ts'o
2016-03-16 1:51 ` Darrick J. Wong
[not found] ` <20160316015139.GC5826-PTl6brltDGh4DFYR7WNSRA@public.gmane.org>
2016-03-16 21:45 ` Andreas Dilger
2016-03-16 21:45 ` Andreas Dilger
[not found] ` <7674C689-C07E-4D38-85EB-4FD9B55CBB35-m1MBpc4rdrD3fQ9qLvQP4Q@public.gmane.org>
2016-03-17 0:15 ` Theodore Ts'o
2016-03-17 0:15 ` Theodore Ts'o
[not found] ` <20160317001502.GF23593-AKGzg7BKzIDYtjvyW6yDsg@public.gmane.org>
2016-03-17 0:33 ` Eric Sandeen
2016-03-17 0:33 ` Eric Sandeen
2016-03-17 0:59 ` Theodore Ts'o
[not found] ` <56E9FB73.6040803-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2016-03-17 5:18 ` Gregory Farnum
2016-03-17 5:18 ` Gregory Farnum
2016-03-17 12:36 ` Theodore Ts'o
[not found] ` <CAC6JEv-CGaphHj6hVXUhFS+Dc4jS46nO1yOfKF5yA8AnDwqgOw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2016-03-17 17:47 ` Linus Torvalds
2016-03-17 17:47 ` Linus Torvalds
2016-03-17 17:50 ` Ric Wheeler
2016-03-17 17:59 ` Linus Torvalds
2016-03-17 18:35 ` Chris Mason
2016-03-17 18:35 ` Chris Mason
[not found] ` <20160317183512.GA76233-HIXDwvFErZjFYCXBM6kdu7fOX0fSgVTm@public.gmane.org>
2016-03-17 20:49 ` Andreas Dilger
2016-03-17 20:49 ` Andreas Dilger
[not found] ` <819F38A3-51A7-4874-8314-8A6004495716-m1MBpc4rdrD3fQ9qLvQP4Q@public.gmane.org>
2016-03-17 21:00 ` Chris Mason
2016-03-17 21:00 ` Chris Mason
[not found] ` <20160317210018.GA78710-HIXDwvFErZjFYCXBM6kdu7fOX0fSgVTm@public.gmane.org>
2016-03-18 3:20 ` Theodore Ts'o
2016-03-18 3:20 ` Theodore Ts'o
[not found] ` <20160318032023.GK23593-AKGzg7BKzIDYtjvyW6yDsg@public.gmane.org>
2016-03-18 15:15 ` Jeff Moyer
2016-03-18 15:15 ` Jeff Moyer
[not found] ` <x491t7795ro.fsf-RRHT56Q3PSP4kTEheFKJxxDDeQx5vsVwAInAS/Ez/D0@public.gmane.org>
2016-03-18 20:05 ` Martin K. Petersen
2016-03-18 20:05 ` Martin K. Petersen
[not found] ` <CA+55aFzbzXb9ApP5FnVZihWRpWGO1-YnJj_Giip5LfD6=uvf0w-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2016-03-18 6:52 ` Gregory Farnum
2016-03-18 6:52 ` Gregory Farnum
[not found] ` <CAC6JEv-MuU2sWSvftjHhOhZsE2Fz49Ffv6cm1FMnju5egcyvmQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2016-03-18 7:19 ` Linus Torvalds
2016-03-18 7:19 ` Linus Torvalds
2016-03-17 1:01 ` Dave Chinner
2016-03-17 1:01 ` Dave Chinner
2016-03-17 2:38 ` Darrick J. Wong
[not found] ` <20160315225224.GD23848-AKGzg7BKzIDYtjvyW6yDsg@public.gmane.org>
2016-03-18 22:55 ` NeilBrown
2016-03-18 22:55 ` NeilBrown
2016-03-15 23:06 ` Linus Torvalds
[not found] ` <CA+55aFxCpza3_3J8kP9E0gLKHiSitZHjC4UMS_ZfZ_HBTC9=Bg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2016-03-15 23:14 ` Linus Torvalds
2016-03-15 23:14 ` Linus Torvalds
[not found] ` <CA+55aFw80NXB9L7ooxV0zr3oaf4zWzZAJcb87ib58n=toiCn7g-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2016-03-16 0:08 ` Dave Chinner
2016-03-16 0:08 ` Dave Chinner
2016-03-15 23:52 ` Dave Chinner
2016-03-16 0:06 ` Linus Torvalds
[not found] ` <CA+55aFxZ=feGd+QGdhCN28kjd2XJO3PCj9NBoJJZ5E8_WMJiMA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2016-03-16 0:30 ` Eric Sandeen
2016-03-16 0:30 ` Eric Sandeen
[not found] ` <56E8A916.8050702-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2016-03-16 0:51 ` Chris Mason
2016-03-16 0:51 ` Chris Mason
[not found] ` <20160316005117.GA34410-HIXDwvFErZjFYCXBM6kdu7fOX0fSgVTm@public.gmane.org>
2016-03-16 22:23 ` Chris Mason
2016-03-16 22:23 ` Chris Mason
[not found] ` <20160316222343.GA53649-HIXDwvFErZjFYCXBM6kdu7fOX0fSgVTm@public.gmane.org>
2016-03-17 13:49 ` Ric Wheeler
2016-03-17 13:49 ` Ric Wheeler
2016-03-15 22:38 ` Eric Sandeen
2016-03-15 22:38 ` Eric Sandeen
2016-03-03 22:56 ` Dave Chinner
2016-03-04 2:30 ` Thomas Schoebel-Theuer
2016-03-04 2:30 ` Thomas Schoebel-Theuer
2016-03-03 18:14 ` Linus Torvalds
2016-03-03 18:14 ` Linus Torvalds
2016-03-02 9:15 ` [PATCH v5.1 0/2] create BLKZEROOUT ioctl that invalidates page cache Arnd Bergmann
2016-03-02 9:44 ` Christoph Hellwig
2016-03-02 9:44 ` Christoph Hellwig
[not found] ` <20160302094416.GA16631-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>
2016-03-02 10:55 ` Arnd Bergmann
2016-03-02 10:55 ` Arnd Bergmann
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