From: Theodore Ts'o Subject: [PATCH 2.6.33.y 25/40] ext4: stop issuing discards if not supported by device Date: Tue, 1 Jun 2010 08:03:12 -0400 Message-ID: <1275393807-14369-25-git-send-email-tytso@mit.edu> References: <1275393807-14369-1-git-send-email-tytso@mit.edu> Cc: Ext4 Developers List , Eric Sandeen , "Theodore Ts'o" To: stable@vger.kernel.org Return-path: Received: from THUNK.ORG ([69.25.196.29]:47319 "EHLO thunker.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756093Ab0FAMDh (ORCPT ); Tue, 1 Jun 2010 08:03:37 -0400 In-Reply-To: <1275393807-14369-1-git-send-email-tytso@mit.edu> Sender: linux-ext4-owner@vger.kernel.org List-ID: From: Eric Sandeen commit a30eec2a8650a77f754e84b2e15f062fe652baa7 upstream (as of v2.6.34-git13) Turn off issuance of discard requests if the device does not support it - similar to the action we take for barriers. This will save a little computation time if a non-discardable device is mounted with -o discard, and also makes it obvious that it's not doing what was asked at mount time ... Signed-off-by: Eric Sandeen Signed-off-by: "Theodore Ts'o" --- fs/ext4/mballoc.c | 8 +++++++- 1 files changed, 7 insertions(+), 1 deletions(-) diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index e71593f..d0ddea0 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -2536,6 +2536,7 @@ static void release_blocks_on_commit(journal_t *journal, transaction_t *txn) entry->count, entry->group, entry); if (test_opt(sb, DISCARD)) { + int ret; ext4_fsblk_t discard_block; discard_block = entry->start_blk + @@ -2543,7 +2544,12 @@ static void release_blocks_on_commit(journal_t *journal, transaction_t *txn) trace_ext4_discard_blocks(sb, (unsigned long long)discard_block, entry->count); - sb_issue_discard(sb, discard_block, entry->count); + ret = sb_issue_discard(sb, discard_block, entry->count); + if (ret == EOPNOTSUPP) { + ext4_warning(sb, __func__, + "discard not supported, disabling"); + clear_opt(EXT4_SB(sb)->s_mount_opt, DISCARD); + } } err = ext4_mb_load_buddy(sb, entry->group, &e4b); -- 1.6.6.1.1.g974db.dirty