From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Sandeen Subject: Re: [PATCH 5/7] mke2fs: Change -K option to discard/nodiscard Date: Tue, 26 Oct 2010 13:41:34 -0500 Message-ID: <4CC720DE.6000901@redhat.com> References: <1288115658-7004-1-git-send-email-lczerner@redhat.com> <1288115658-7004-6-git-send-email-lczerner@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: linux-ext4@vger.kernel.org, tytso@mit.edu, adilger@dilger.ca To: Lukas Czerner Return-path: Received: from mx1.redhat.com ([209.132.183.28]:54661 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760050Ab0JZSlk (ORCPT ); Tue, 26 Oct 2010 14:41:40 -0400 In-Reply-To: <1288115658-7004-6-git-send-email-lczerner@redhat.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: Lukas Czerner wrote: > It would be nice to have consistent "discard" options in every system > tool (mount, fsck, mkfs) taking advantage of discards. Also "discard" > and "nodiscard" is more descriptive instead of just "-K" and can be > easily defaulted and it is something we can not do with "-K". > > With this commit you need to specify extended option like this: > > ./mke2fs -T -E nodiscard > > in order make a filesystem without discarding the device first. And > > ./mke2fs -T -E discard > > respectively. Sadly, we probably need to map -K onto -E nodiscard and deprecate it for now, rather than just removing it altogether? -Eric > Signed-off-by: Lukas Czerner > --- > misc/mke2fs.8.in | 18 +++++++++++------- > misc/mke2fs.c | 13 ++++++++----- > 2 files changed, 19 insertions(+), 12 deletions(-) > > diff --git a/misc/mke2fs.8.in b/misc/mke2fs.8.in > index b46e7e2..6b437bc 100644 > --- a/misc/mke2fs.8.in > +++ b/misc/mke2fs.8.in > @@ -45,9 +45,6 @@ mke2fs \- create an ext2/ext3/ext4 filesystem > .I journal-options > ] > [ > -.B \-K > -] > -[ > .B \-N > .I number-of-inodes > ] > @@ -240,6 +237,17 @@ enable lazy inode table initialization. > .B test_fs > Set a flag in the filesystem superblock indicating that it may be > mounted using experimental kernel code, such as the ext4dev filesystem. > +.TP > +.BI discard > +Attempt to discard blocks at mkfs time (discarding blocks initially is useful > +on solid state devices and sparse / thin-provisioned storage). When the device > +advertise that discard also zeroes data (any subsequent read after the discard > +and before write returns zero), then mark all not-yet-zeroed inode table as > +zeroed. This significantly speeds up filesystem initialization. This is set > +as default. > +.TP > +.BI nodiscard > +Do not attempt to discard blocks at mkfs time. > .RE > .TP > .BI \-f " fragment-size" > @@ -369,10 +377,6 @@ and may be no more than 102,400 filesystem blocks. > @JDEV@.BR size " or " device > @JDEV@options can be given for a filesystem. > .TP > -.BI \-K > -Keep, do not attempt to discard blocks at mkfs time (discarding blocks initially > -is useful on solid state devices and sparse / thin-provisioned storage). > -.TP > .BI \-l " filename" > Read the bad blocks list from > .IR filename . > diff --git a/misc/mke2fs.c b/misc/mke2fs.c > index 0980045..32e3a2b 100644 > --- a/misc/mke2fs.c > +++ b/misc/mke2fs.c > @@ -753,6 +753,10 @@ static void parse_extended_opts(struct ext2_super_block *param, > lazy_itable_init = strtoul(arg, &p, 0); > else > lazy_itable_init = 1; > + } else if (!strcmp(token, "discard")) { > + discard = 1; > + } else if (!strcmp(token, "nodiscard")) { > + discard = 0; > } else { > r_usage++; > badopt = token; > @@ -768,7 +772,9 @@ static void parse_extended_opts(struct ext2_super_block *param, > "\tstripe-width=\n" > "\tresize=\n" > "\tlazy_itable_init=<0 to disable, 1 to enable>\n" > - "\ttest_fs\n\n"), > + "\ttest_fs\n" > + "\tdiscard\n" > + "\tnodiscard\n\n"), > badopt ? badopt : ""); > free(buf); > exit(1); > @@ -1168,7 +1174,7 @@ static void PRS(int argc, char *argv[]) > } > > while ((c = getopt (argc, argv, > - "b:cf:g:G:i:jl:m:no:qr:s:t:vE:FI:J:KL:M:N:O:R:ST:U:V")) != EOF) { > + "b:cf:g:G:i:jl:m:no:qr:s:t:vE:FI:J:L:M:N:O:R:ST:U:V")) != EOF) { > switch (c) { > case 'b': > blocksize = strtol(optarg, &tmp, 0); > @@ -1247,9 +1253,6 @@ static void PRS(int argc, char *argv[]) > case 'J': > parse_journal_opts(optarg); > break; > - case 'K': > - discard = 0; > - break; > case 'j': > if (!journal_size) > journal_size = -1;