From: Theodore Ts'o Subject: [PATCH 2.6.33.y 28/40] ext4: clean up inode bitmaps manipulation in ext4_free_inode Date: Tue, 1 Jun 2010 08:03:15 -0400 Message-ID: <1275393807-14369-28-git-send-email-tytso@mit.edu> References: <1275393807-14369-1-git-send-email-tytso@mit.edu> Cc: Ext4 Developers List , Dmitry Monakhov , "Theodore Ts'o" To: stable@vger.kernel.org Return-path: Received: from THUNK.ORG ([69.25.196.29]:47309 "EHLO thunker.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756089Ab0FAMDf (ORCPT ); Tue, 1 Jun 2010 08:03:35 -0400 In-Reply-To: <1275393807-14369-1-git-send-email-tytso@mit.edu> Sender: linux-ext4-owner@vger.kernel.org List-ID: From: Dmitry Monakhov commit d17413c08cd2b1dd2bf2cfdbb0f7b736b2b2b15c upstrea (as of v2..34-git13) - Reorganize locking scheme to batch two atomic operation in to one. This also allow us to state what healthy group must obey following rule ext4_free_inodes_count(sb, gdp) == ext4_count_free(inode_bitmap, NUM); - Fix possible undefined pointer dereference. - Even if group descriptor stats aren't accessible we have to update inode bitmaps. - Move non-group members update out of group_lock. Note: this commit has been observed to fix fs corruption problems under heavy fs load Signed-off-by: Dmitry Monakhov Signed-off-by: "Theodore Ts'o" --- fs/ext4/ialloc.c | 83 ++++++++++++++++++++++++----------------------------- 1 files changed, 38 insertions(+), 45 deletions(-) diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c index 8b4bb11..c55275a 100644 --- a/fs/ext4/ialloc.c +++ b/fs/ext4/ialloc.c @@ -244,57 +244,50 @@ void ext4_free_inode(handle_t *handle, struct inode *inode) if (fatal) goto error_return; - /* Ok, now we can actually update the inode bitmaps.. */ - cleared = ext4_clear_bit_atomic(ext4_group_lock_ptr(sb, block_group), - bit, bitmap_bh->b_data); - if (!cleared) - ext4_error(sb, "ext4_free_inode", - "bit already cleared for inode %lu", ino); - else { - gdp = ext4_get_group_desc(sb, block_group, &bh2); - + fatal = -ESRCH; + gdp = ext4_get_group_desc(sb, block_group, &bh2); + if (gdp) { BUFFER_TRACE(bh2, "get_write_access"); fatal = ext4_journal_get_write_access(handle, bh2); - if (fatal) goto error_return; - - if (gdp) { - ext4_lock_group(sb, block_group); - count = ext4_free_inodes_count(sb, gdp) + 1; - ext4_free_inodes_set(sb, gdp, count); - if (is_directory) { - count = ext4_used_dirs_count(sb, gdp) - 1; - ext4_used_dirs_set(sb, gdp, count); - if (sbi->s_log_groups_per_flex) { - ext4_group_t f; - - f = ext4_flex_group(sbi, block_group); - atomic_dec(&sbi->s_flex_groups[f].used_dirs); - } + } + ext4_lock_group(sb, block_group); + cleared = ext4_clear_bit(bit, bitmap_bh->b_data); + if (fatal || !cleared) { + ext4_unlock_group(sb, block_group); + goto out; + } - } - gdp->bg_checksum = ext4_group_desc_csum(sbi, - block_group, gdp); - ext4_unlock_group(sb, block_group); - percpu_counter_inc(&sbi->s_freeinodes_counter); - if (is_directory) - percpu_counter_dec(&sbi->s_dirs_counter); - - if (sbi->s_log_groups_per_flex) { - ext4_group_t f; - - f = ext4_flex_group(sbi, block_group); - atomic_inc(&sbi->s_flex_groups[f].free_inodes); - } - } - BUFFER_TRACE(bh2, "call ext4_handle_dirty_metadata"); - err = ext4_handle_dirty_metadata(handle, NULL, bh2); - if (!fatal) fatal = err; + count = ext4_free_inodes_count(sb, gdp) + 1; + ext4_free_inodes_set(sb, gdp, count); + if (is_directory) { + count = ext4_used_dirs_count(sb, gdp) - 1; + ext4_used_dirs_set(sb, gdp, count); + percpu_counter_dec(&sbi->s_dirs_counter); } - BUFFER_TRACE(bitmap_bh, "call ext4_handle_dirty_metadata"); - err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh); - if (!fatal) - fatal = err; - sb->s_dirt = 1; + gdp->bg_checksum = ext4_group_desc_csum(sbi, block_group, gdp); + ext4_unlock_group(sb, block_group); + + percpu_counter_inc(&sbi->s_freeinodes_counter); + if (sbi->s_log_groups_per_flex) { + ext4_group_t f = ext4_flex_group(sbi, block_group); + + atomic_inc(&sbi->s_flex_groups[f].free_inodes); + if (is_directory) + atomic_dec(&sbi->s_flex_groups[f].used_dirs); + } + BUFFER_TRACE(bh2, "call ext4_handle_dirty_metadata"); + fatal = ext4_handle_dirty_metadata(handle, NULL, bh2); +out: + if (cleared) { + BUFFER_TRACE(bitmap_bh, "call ext4_handle_dirty_metadata"); + err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh); + if (!fatal) + fatal = err; + sb->s_dirt = 1; + } else + ext4_error(sb, "ext4_free_inode", + "bit already cleared for inode %lu", ino); + error_return: brelse(bitmap_bh); ext4_std_error(sb, fatal); -- 1.6.6.1.1.g974db.dirty