From d5e2003c2bcda93a8f2e668eb4642d70c9c38301 Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Thu, 4 Aug 2011 14:52:27 +0000 Subject: Btrfs: detect wether a device supports discard We have a problem where if a user specifies discard but doesn't actually support it we will return EOPNOTSUPP from btrfs_discard_extent. This is a problem because this gets called (in a fashion) from the tree log recovery code, which has a nice little BUG_ON(ret) after it, which causes us to fail the tree log replay. So instead detect wether our devices support discard when we're adding them and then don't issue discards if we know that the device doesn't support it. And just for good measure set ret = 0 in btrfs_issue_discard just in case we still get EOPNOTSUPP so we don't screw anybody up like this again. Thanks, Signed-off-by: Josef Bacik Signed-off-by: Chris Mason --- fs/btrfs/extent-tree.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) (limited to 'fs/btrfs/extent-tree.c') diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 66bac226944..059dfa048cc 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -1782,6 +1782,9 @@ static int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr, for (i = 0; i < multi->num_stripes; i++, stripe++) { + if (!stripe->dev->can_discard) + continue; + ret = btrfs_issue_discard(stripe->dev->bdev, stripe->physical, stripe->length); @@ -1789,11 +1792,16 @@ static int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr, discarded_bytes += stripe->length; else if (ret != -EOPNOTSUPP) break; + + /* + * Just in case we get back EOPNOTSUPP for some reason, + * just ignore the return value so we don't screw up + * people calling discard_extent. + */ + ret = 0; } kfree(multi); } - if (discarded_bytes && ret == -EOPNOTSUPP) - ret = 0; if (actual_bytes) *actual_bytes = discarded_bytes; -- cgit v1.2.3-70-g09d2