From e244a0aeb6a599c19a7c802cda6e2d67c847b154 Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@lst.de>
Date: Wed, 14 Oct 2009 09:24:59 -0400
Subject: Btrfs: add -o discard option
Enable discard by default is not a good idea given the the trim speed
of SSD prototypes we've seen, and the carecteristics for many high-end
arrays. Turn of discards by default and require the -o discard option
to enable them on.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
---
fs/btrfs/super.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
(limited to 'fs/btrfs/super.c')
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 3fbbf0761ac2..939b68f0612d 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -66,7 +66,8 @@ enum {
Opt_degraded, Opt_subvol, Opt_device, Opt_nodatasum, Opt_nodatacow,
Opt_max_extent, Opt_max_inline, Opt_alloc_start, Opt_nobarrier,
Opt_ssd, Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl,
- Opt_compress, Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_err,
+ Opt_compress, Opt_notreelog, Opt_ratio, Opt_flushoncommit,
+ Opt_discard, Opt_err,
};
static match_table_t tokens = {
@@ -88,6 +89,7 @@ static match_table_t tokens = {
{Opt_notreelog, "notreelog"},
{Opt_flushoncommit, "flushoncommit"},
{Opt_ratio, "metadata_ratio=%d"},
+ {Opt_discard, "discard"},
{Opt_err, NULL},
};
@@ -257,6 +259,9 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
info->metadata_ratio);
}
break;
+ case Opt_discard:
+ btrfs_set_opt(info->mount_opt, DISCARD);
+ break;
default:
break;
}
--
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