From: Theodore Ts'o Subject: [PATCH] ext4: remove ext4_mb_return_to_preallocation() Date: Sat, 8 Jan 2011 22:43:29 -0500 Message-ID: <1294544609-14225-1-git-send-email-tytso@mit.edu> References: <20110109030447.GX21922@thunk.org> Cc: Theodore Ts'o , Jiaying Zhang To: Ext4 Developers List Return-path: Received: from THUNK.ORG ([69.25.196.29]:43998 "EHLO thunker.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752226Ab1AIDnf (ORCPT ); Sat, 8 Jan 2011 22:43:35 -0500 In-Reply-To: <20110109030447.GX21922@thunk.org> Sender: linux-ext4-owner@vger.kernel.org List-ID: This function was never implemented, except for a BUG_ON which was tripping when ext4 is run without a journal. The problem is that although the comment asserts that "truncate (which is the only way to free block) discards all preallocations", ext4_free_blocks() is also called in various error recovery paths when blocks have been allocated, but for various reasons, we were not able to use those data blocks (for example, because we ran out of memory while trying to manipulate the extent tree, or some other similar situation). In addition to the fact that this function isn't implemented except for the incorrect BUG_ON, the single caller of this function, ext4_free_blocks(), doesn't use it all if the journal is enabled. So remove the (stub) function entirely for now. If we decide it's better to add it back, it's only going to be useful with a relatively large number of code changes anyway. Google-Bug-Id: 3236408 Cc: Jiaying Zhang Signed-off-by: "Theodore Ts'o" --- fs/ext4/mballoc.c | 14 -------------- 1 files changed, 0 insertions(+), 14 deletions(-) diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 5bbf6e3..85b6d44 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -3881,19 +3881,6 @@ repeat: } } -/* - * finds all preallocated spaces and return blocks being freed to them - * if preallocated space becomes full (no block is used from the space) - * then the function frees space in buddy - * XXX: at the moment, truncate (which is the only way to free blocks) - * discards all preallocations - */ -static void ext4_mb_return_to_preallocation(struct inode *inode, - struct ext4_buddy *e4b, - sector_t block, int count) -{ - BUG_ON(!list_empty(&EXT4_I(inode)->i_prealloc_list)); -} #ifdef CONFIG_EXT4_DEBUG static void ext4_mb_show_ac(struct ext4_allocation_context *ac) { @@ -4648,7 +4635,6 @@ do_more: ext4_lock_group(sb, block_group); mb_clear_bits(bitmap_bh->b_data, bit, count); mb_free_blocks(inode, &e4b, bit, count); - ext4_mb_return_to_preallocation(inode, &e4b, block, count); } ret = ext4_free_blks_count(sb, gdp) + count; -- 1.7.3.1