From 6bc6e63fcd7dac9e633ea29f1fddd9580ab28f3f Mon Sep 17 00:00:00 2001 From: "Aneesh Kumar K.V" Date: Fri, 10 Oct 2008 09:39:00 -0400 Subject: ext4: Add percpu dirty block accounting. This patch adds dirty block accounting using percpu_counters. Delayed allocation block reservation is now done by updating dirty block counter. In a later patch we switch to non delalloc mode if the filesystem free blocks is greater than 150% of total filesystem dirty blocks Signed-off-by: Aneesh Kumar K.V Signed-off-by: Mingming Cao Signed-off-by: "Theodore Ts'o" --- fs/ext4/balloc.c | 62 ++++++++++++++++++++++++++++++++++++-------------------- 1 file changed, 40 insertions(+), 22 deletions(-) (limited to 'fs/ext4/balloc.c') diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c index 57909882c08..edef0023e6e 100644 --- a/fs/ext4/balloc.c +++ b/fs/ext4/balloc.c @@ -1605,26 +1605,38 @@ out: int ext4_claim_free_blocks(struct ext4_sb_info *sbi, ext4_fsblk_t nblocks) { - s64 free_blocks; + s64 free_blocks, dirty_blocks; ext4_fsblk_t root_blocks = 0; struct percpu_counter *fbc = &sbi->s_freeblocks_counter; + struct percpu_counter *dbc = &sbi->s_dirtyblocks_counter; - free_blocks = percpu_counter_read(fbc); + free_blocks = percpu_counter_read_positive(fbc); + dirty_blocks = percpu_counter_read_positive(dbc); if (!capable(CAP_SYS_RESOURCE) && sbi->s_resuid != current->fsuid && (sbi->s_resgid == 0 || !in_group_p(sbi->s_resgid))) root_blocks = ext4_r_blocks_count(sbi->s_es); - if (free_blocks - (nblocks + root_blocks) < EXT4_FREEBLOCKS_WATERMARK) - free_blocks = percpu_counter_sum(&sbi->s_freeblocks_counter); - - if (free_blocks < (root_blocks + nblocks)) + if (free_blocks - (nblocks + root_blocks + dirty_blocks) < + EXT4_FREEBLOCKS_WATERMARK) { + free_blocks = percpu_counter_sum(fbc); + dirty_blocks = percpu_counter_sum(dbc); + if (dirty_blocks < 0) { + printk(KERN_CRIT "Dirty block accounting " + "went wrong %lld\n", + dirty_blocks); + } + } + /* Check whether we have space after + * accounting for current dirty blocks + */ + if (free_blocks < ((s64)(root_blocks + nblocks) + dirty_blocks)) /* we don't have free space */ return -ENOSPC; - /* reduce fs free blocks counter */ - percpu_counter_sub(fbc, nblocks); + /* Add the blocks to nblocks */ + percpu_counter_add(dbc, nblocks); return 0; } @@ -1640,23 +1652,28 @@ int ext4_claim_free_blocks(struct ext4_sb_info *sbi, ext4_fsblk_t ext4_has_free_blocks(struct ext4_sb_info *sbi, ext4_fsblk_t nblocks) { - ext4_fsblk_t free_blocks; + ext4_fsblk_t free_blocks, dirty_blocks; ext4_fsblk_t root_blocks = 0; + struct percpu_counter *fbc = &sbi->s_freeblocks_counter; + struct percpu_counter *dbc = &sbi->s_dirtyblocks_counter; - free_blocks = percpu_counter_read_positive(&sbi->s_freeblocks_counter); + free_blocks = percpu_counter_read_positive(fbc); + dirty_blocks = percpu_counter_read_positive(dbc); if (!capable(CAP_SYS_RESOURCE) && sbi->s_resuid != current->fsuid && (sbi->s_resgid == 0 || !in_group_p(sbi->s_resgid))) root_blocks = ext4_r_blocks_count(sbi->s_es); - if (free_blocks - (nblocks + root_blocks) < EXT4_FREEBLOCKS_WATERMARK) - free_blocks = percpu_counter_sum_positive(&sbi->s_freeblocks_counter); - - if (free_blocks <= root_blocks) + if (free_blocks - (nblocks + root_blocks + dirty_blocks) < + EXT4_FREEBLOCKS_WATERMARK) { + free_blocks = percpu_counter_sum_positive(fbc); + dirty_blocks = percpu_counter_sum_positive(dbc); + } + if (free_blocks <= (root_blocks + dirty_blocks)) /* we don't have free space */ return 0; - if (free_blocks - root_blocks < nblocks) + if (free_blocks - (root_blocks + dirty_blocks) < nblocks) return free_blocks - root_blocks; return nblocks; } @@ -1943,13 +1960,14 @@ allocated: le16_add_cpu(&gdp->bg_free_blocks_count, -num); gdp->bg_checksum = ext4_group_desc_csum(sbi, group_no, gdp); spin_unlock(sb_bgl_lock(sbi, group_no)); - if (!EXT4_I(inode)->i_delalloc_reserved_flag && (*count != num)) { - /* - * we allocated less blocks than we - * claimed. Add the difference back. - */ - percpu_counter_add(&sbi->s_freeblocks_counter, *count - num); - } + percpu_counter_sub(&sbi->s_freeblocks_counter, num); + /* + * Now reduce the dirty block count also. Should not go negative + */ + if (!EXT4_I(inode)->i_delalloc_reserved_flag) + percpu_counter_sub(&sbi->s_dirtyblocks_counter, *count); + else + percpu_counter_sub(&sbi->s_dirtyblocks_counter, num); if (sbi->s_log_groups_per_flex) { ext4_group_t flex_group = ext4_flex_group(sbi, group_no); spin_lock(sb_bgl_lock(sbi, flex_group)); -- cgit v1.2.3