ext4: refine extent status tree

This commit refines the extent status tree code.

1) A prefix 'es_' is added to to the extent status tree structure
members.

2) Refactored es_remove_extent() so that __es_remove_extent() can be
used by es_insert_extent() to remove the old extent entry(-ies) before
inserting a new one.

3) Rename extent_status_end() to ext4_es_end()

4) ext4_es_can_be_merged() is define to check whether two extents can
be merged or not.

5) Update and clarified comments.

Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
This commit is contained in:
Zheng Liu
2013-02-18 00:26:51 -05:00
committed by Theodore Ts'o
parent 0f70b40613
commit 06b0c88621
5 changed files with 221 additions and 182 deletions

View File

@ -464,10 +464,9 @@ static loff_t ext4_seek_data(struct file *file, loff_t offset, loff_t maxsize)
* If there is a delay extent at this offset,
* it will be as a data.
*/
es.start = last;
es.es_lblk = last;
(void)ext4_es_find_extent(inode, &es);
if (last >= es.start &&
last < es.start + es.len) {
if (es.es_len != 0 && in_range(last, es.es_lblk, es.es_len)) {
if (last != start)
dataoff = last << blkbits;
break;
@ -549,11 +548,10 @@ static loff_t ext4_seek_hole(struct file *file, loff_t offset, loff_t maxsize)
* If there is a delay extent at this offset,
* we will skip this extent.
*/
es.start = last;
es.es_lblk = last;
(void)ext4_es_find_extent(inode, &es);
if (last >= es.start &&
last < es.start + es.len) {
last = es.start + es.len;
if (es.es_len != 0 && in_range(last, es.es_lblk, es.es_len)) {
last = es.es_lblk + es.es_len;
holeoff = last << blkbits;
continue;
}