From 68629f29c6764c37ebdceec2f6bbef6637eaf420 Mon Sep 17 00:00:00 2001 From: "Aneesh Kumar K.V" Date: Mon, 8 Sep 2008 23:09:17 -0400 Subject: [PATCH] ext4: Fix ext4 nomballoc allocator for ENOSPC We run into ENOSPC error on nonmballoc ext4, even when there is free blocks on the filesystem. The patch includes two changes: a) Set reservation to NULL if we trying to allocate near group_target_block from the goal group if the free block in the group is less than windows. This should give us a better chance to allocate near group_target_block. This also ensures that if we are not allocating near group_target_block then we don't trun off reservation. This should enable us to allocate with reservation from other groups that have large free blocks count. b) we don't need to check the window size if the block reservation is off. Signed-off-by: Aneesh Kumar K.V Signed-off-by: Mingming Cao Signed-off-by: "Theodore Ts'o" --- fs/ext4/balloc.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c index a425e78c73eb..ae26c37e398e 100644 --- a/fs/ext4/balloc.c +++ b/fs/ext4/balloc.c @@ -1804,15 +1804,17 @@ retry_alloc: goto io_error; free_blocks = le16_to_cpu(gdp->bg_free_blocks_count); - /* - * if there is not enough free blocks to make a new resevation - * turn off reservation for this allocation - */ - if (my_rsv && (free_blocks < windowsz) - && (rsv_is_empty(&my_rsv->rsv_window))) - my_rsv = NULL; if (free_blocks > 0) { + /* + * try to allocate with group target block + * in the goal group. If we have low free_blocks + * count turn off reservation + */ + if (my_rsv && (free_blocks < windowsz) + && (rsv_is_empty(&my_rsv->rsv_window))) + my_rsv = NULL; + bitmap_bh = ext4_read_block_bitmap(sb, group_no); if (!bitmap_bh) goto io_error; @@ -1845,7 +1847,7 @@ retry_alloc: * free blocks is less than half of the reservation * window size. */ - if (free_blocks <= (windowsz/2)) + if (my_rsv && (free_blocks <= (windowsz/2))) continue; brelse(bitmap_bh); -- 2.30.2