From 3d9b96ff98a809ae87c6b86e3354e3191aefb0a3 Mon Sep 17 00:00:00 2001 From: Zheng Liu Date: Mon, 18 Feb 2013 00:28:47 -0500 Subject: [PATCH] ext4: track all extent status in extent status tree By recording the phycisal block and status, extent status tree is able to track the status of every extents. When we call _map_blocks functions to lookup an extent or create a new written/unwritten/delayed extent, this extent will be inserted into extent status tree. We don't load all extents from disk in alloc_inode() because it costs too much memory, and if a file is opened and closed frequently it will takes too much time to load all extent information. So currently when we create/lookup an extent, this extent will be inserted into extent status tree. Hence, the extent status tree may not comprehensively contain all of the extents found in the file. Here a condition we need to take care is that an extent might contains unwritten and delayed status simultaneously because an extent is delayed allocated and could be allocated by fallocate. At this time we need to keep delayed status because later we need to update delayed reservation space using it. Signed-off-by: Zheng Liu Signed-off-by: "Theodore Ts'o" Cc: Jan kara --- fs/ext4/ext4.h | 3 ++ fs/ext4/extents.c | 20 +++++++++---- fs/ext4/inode.c | 76 +++++++++++++++++++++++++++++++---------------- 3 files changed, 69 insertions(+), 30 deletions(-) diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 110018a7f6f3..1d72eddcfa92 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -2602,6 +2602,9 @@ extern struct ext4_ext_path *ext4_ext_find_extent(struct inode *, ext4_lblk_t, struct ext4_ext_path *); extern void ext4_ext_drop_refs(struct ext4_ext_path *); extern int ext4_ext_check_inode(struct inode *inode); +extern int ext4_find_delalloc_range(struct inode *inode, + ext4_lblk_t lblk_start, + ext4_lblk_t lblk_end); extern int ext4_find_delalloc_cluster(struct inode *inode, ext4_lblk_t lblk); extern int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, __u64 start, __u64 len); diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 1aba9660f8a4..deabfacb3455 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -2076,8 +2076,18 @@ static int ext4_fill_fiemap_extents(struct inode *inode, break; } - /* This is possible iff next == next_del == EXT_MAX_BLOCKS */ - if (next == next_del) { + /* + * This is possible iff next == next_del == EXT_MAX_BLOCKS. + * we need to check next == EXT_MAX_BLOCKS because it is + * possible that an extent is with unwritten and delayed + * status due to when an extent is delayed allocated and + * is allocated by fallocate status tree will track both of + * them in a extent. + * + * So we could return a unwritten and delayed extent, and + * its block is equal to 'next'. + */ + if (next == next_del && next == EXT_MAX_BLOCKS) { flags |= FIEMAP_EXTENT_LAST; if (unlikely(next_del != EXT_MAX_BLOCKS || next != EXT_MAX_BLOCKS)) { @@ -3522,9 +3532,9 @@ out: * * Return 1 if there is a delalloc block in the range, otherwise 0. */ -static int ext4_find_delalloc_range(struct inode *inode, - ext4_lblk_t lblk_start, - ext4_lblk_t lblk_end) +int ext4_find_delalloc_range(struct inode *inode, + ext4_lblk_t lblk_start, + ext4_lblk_t lblk_end) { struct extent_status es; diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 084b8212cf95..576b586b61aa 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -526,20 +526,26 @@ int ext4_map_blocks(handle_t *handle, struct inode *inode, retval = ext4_ind_map_blocks(handle, inode, map, flags & EXT4_GET_BLOCKS_KEEP_SIZE); } + if (retval > 0) { + int ret; + unsigned long long status; + + status = map->m_flags & EXT4_MAP_UNWRITTEN ? + EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN; + if (!(flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) && + ext4_find_delalloc_range(inode, map->m_lblk, + map->m_lblk + map->m_len - 1)) + status |= EXTENT_STATUS_DELAYED; + ret = ext4_es_insert_extent(inode, map->m_lblk, + map->m_len, map->m_pblk, status); + if (ret < 0) + retval = ret; + } if (!(flags & EXT4_GET_BLOCKS_NO_LOCK)) up_read((&EXT4_I(inode)->i_data_sem)); if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) { - int ret; - if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) { - /* delayed alloc may be allocated by fallocate and - * coverted to initialized by directIO. - * we need to handle delayed extent here. - */ - down_write((&EXT4_I(inode)->i_data_sem)); - goto delayed_mapped; - } - ret = check_block_validity(inode, map); + int ret = check_block_validity(inode, map); if (ret != 0) return ret; } @@ -608,18 +614,23 @@ int ext4_map_blocks(handle_t *handle, struct inode *inode, (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)) ext4_da_update_reserve_space(inode, retval, 1); } - if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) { + if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) ext4_clear_inode_state(inode, EXT4_STATE_DELALLOC_RESERVED); - if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) { - int ret; -delayed_mapped: - /* delayed allocation blocks has been allocated */ - ret = ext4_es_remove_extent(inode, map->m_lblk, - map->m_len); - if (ret < 0) - retval = ret; - } + if (retval > 0) { + int ret; + unsigned long long status; + + status = map->m_flags & EXT4_MAP_UNWRITTEN ? + EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN; + if (!(flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) && + ext4_find_delalloc_range(inode, map->m_lblk, + map->m_lblk + map->m_len - 1)) + status |= EXTENT_STATUS_DELAYED; + ret = ext4_es_insert_extent(inode, map->m_lblk, map->m_len, + map->m_pblk, status); + if (ret < 0) + retval = ret; } up_write((&EXT4_I(inode)->i_data_sem)); @@ -1765,6 +1776,7 @@ static int ext4_da_map_blocks(struct inode *inode, sector_t iblock, retval = ext4_ind_map_blocks(NULL, inode, map, 0); if (retval == 0) { + int ret; /* * XXX: __block_prepare_write() unmaps passed block, * is it OK? @@ -1772,16 +1784,20 @@ static int ext4_da_map_blocks(struct inode *inode, sector_t iblock, /* If the block was allocated from previously allocated cluster, * then we dont need to reserve it again. */ if (!(map->m_flags & EXT4_MAP_FROM_CLUSTER)) { - retval = ext4_da_reserve_space(inode, iblock); - if (retval) + ret = ext4_da_reserve_space(inode, iblock); + if (ret) { /* not enough space to reserve */ + retval = ret; goto out_unlock; + } } - retval = ext4_es_insert_extent(inode, map->m_lblk, map->m_len, - ~0, EXTENT_STATUS_DELAYED); - if (retval) + ret = ext4_es_insert_extent(inode, map->m_lblk, map->m_len, + ~0, EXTENT_STATUS_DELAYED); + if (ret) { + retval = ret; goto out_unlock; + } /* Clear EXT4_MAP_FROM_CLUSTER flag since its purpose is served * and it should not appear on the bh->b_state. @@ -1791,6 +1807,16 @@ static int ext4_da_map_blocks(struct inode *inode, sector_t iblock, map_bh(bh, inode->i_sb, invalid_block); set_buffer_new(bh); set_buffer_delay(bh); + } else if (retval > 0) { + int ret; + unsigned long long status; + + status = map->m_flags & EXT4_MAP_UNWRITTEN ? + EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN; + ret = ext4_es_insert_extent(inode, map->m_lblk, map->m_len, + map->m_pblk, status); + if (ret != 0) + retval = ret; } out_unlock: -- 2.39.5