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Date: Tue, 12 Feb 2013 22:46:22 -0500
From: Theodore Ts'o <tytso@....edu>
To: Ext4 Developers List <linux-ext4@...r.kernel.org>
Cc: Zheng Liu <wenqing.lz@...bao.com>, "Theodore Ts'o" <tytso@....edu>,
Jan kara <jack@...e.cz>
Subject: [PATCH 2/2] ext4: track all extent status in extent status tree
From: Zheng Liu <wenqing.lz@...bao.com>
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. The hole
extent is inserted in ext4_ext_put_gap_in_cache(). If there is no any
extent, we will not insert a hole extent [0, ~0] into the extent status
tree in order to reduce the complextiy of code.
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.
Signed-off-by: Zheng Liu <wenqing.lz@...bao.com>
Signed-off-by: "Theodore Ts'o" <tytso@....edu>
Cc: Jan kara <jack@...e.cz>
---
fs/ext4/extents_status.c | 18 ++++++++++++----
fs/ext4/inode.c | 53 ++++++++++++++++++++++++++++++------------------
2 files changed, 47 insertions(+), 24 deletions(-)
diff --git a/fs/ext4/extents_status.c b/fs/ext4/extents_status.c
index df72e95..839a91d 100644
--- a/fs/ext4/extents_status.c
+++ b/fs/ext4/extents_status.c
@@ -267,15 +267,25 @@ ext4_lblk_t ext4_es_find_delayed_extent(struct inode *inode,
es1 = __es_tree_search(&tree->root, es->es_lblk);
out:
- if (es1) {
+ if (es1 && !ext4_es_is_delayed(es1)) {
+ while ((node = rb_next(&es1->rb_node)) != NULL) {
+ es1 = rb_entry(node, struct extent_status, rb_node);
+ if (ext4_es_is_delayed(es1))
+ break;
+ }
+ }
+
+ if (es1 && ext4_es_is_delayed(es1)) {
tree->cache_es = es1;
es->es_lblk = es1->es_lblk;
es->es_len = es1->es_len;
es->es_pblk = es1->es_pblk;
- node = rb_next(&es1->rb_node);
- if (node) {
+ while ((node = rb_next(&es1->rb_node)) != NULL) {
es1 = rb_entry(node, struct extent_status, rb_node);
- ret = es1->es_lblk;
+ if (ext4_es_is_delayed(es1)) {
+ ret = es1->es_lblk;
+ break;
+ }
}
}
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index cd75f65..01875fe 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -524,20 +524,22 @@ 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;
+ 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;
}
@@ -606,18 +608,19 @@ 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;
+ 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));
@@ -1787,6 +1790,16 @@ 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:
--
1.7.12.rc0.22.gcdd159b
--
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