ext4: let ext4 maintain extent status tree

This patch lets ext4 maintain extent status tree.

Currently it only tracks delay extent status in extent status tree.  When a
delay allocation is issued, the related delay extent will be inserted into
extent status tree.  When a delay extent is written out or invalidated, it will
be removed from this tree.

Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: Allison Henderson <achender@linux.vnet.ibm.com>
Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

fs/ext4/extents.c

@@ -4344,6 +4344,8 @@ void ext4_ext_truncate(struct inode *inode)
 
 	last_block = (inode->i_size + sb->s_blocksize - 1)
 			>> EXT4_BLOCK_SIZE_BITS(sb);
+	err = ext4_es_remove_extent(inode, last_block,
+				    EXT_MAX_BLOCKS - last_block);
 	err = ext4_ext_remove_space(inode, last_block, EXT_MAX_BLOCKS - 1);
 
 	/* In a multi-transaction truncate, we only make the final
@@ -4971,6 +4973,8 @@ int ext4_ext_punch_hole(struct file *file, loff_t offset, loff_t length)
 	ext4_ext_invalidate_cache(inode);
 	ext4_discard_preallocations(inode);
 
+	err = ext4_es_remove_extent(inode, first_block,
+				    stop_block - first_block);
 	err = ext4_ext_remove_space(inode, first_block, stop_block - 1);
 
 	ext4_ext_invalidate_cache(inode);

fs/ext4/indirect.c

@@ -1411,6 +1411,7 @@ void ext4_ind_truncate(struct inode *inode)
 	down_write(&ei->i_data_sem);
 
 	ext4_discard_preallocations(inode);
+	ext4_es_remove_extent(inode, last_block, EXT_MAX_BLOCKS - last_block);
 
 	/*
 	 * The orphan list entry will now protect us from any crash which

fs/ext4/inode.c

@@ -574,7 +574,16 @@ int ext4_map_blocks(handle_t *handle, struct inode *inode,
 		up_read((&EXT4_I(inode)->i_data_sem));
 
 	if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) {
-		int ret = check_block_validity(inode, map);
+		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);
 		if (ret != 0)
 			return ret;
 	}
@@ -656,8 +665,16 @@ int ext4_map_blocks(handle_t *handle, struct inode *inode,
 		 * set the BH_Da_Mapped bit on them. Its important to do this
 		 * under the protection of i_data_sem.
 		 */
-		if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED)
+		if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) {
+			int ret;
 			set_buffers_da_mapped(inode, map);
+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;
+		}
 	}
 
 	up_write((&EXT4_I(inode)->i_data_sem));
@@ -1303,6 +1320,7 @@ static void ext4_da_page_release_reservation(struct page *page,
 	struct inode *inode = page->mapping->host;
 	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
 	int num_clusters;
+	ext4_fsblk_t lblk;
 
 	head = page_buffers(page);
 	bh = head;
@@ -1317,11 +1335,15 @@ static void ext4_da_page_release_reservation(struct page *page,
 		curr_off = next_off;
 	} while ((bh = bh->b_this_page) != head);
 
+	if (to_release) {
+		lblk = page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
+		ext4_es_remove_extent(inode, lblk, to_release);
+	}
+
 	/* If we have released all the blocks belonging to a cluster, then we
 	 * need to release the reserved space for that cluster. */
 	num_clusters = EXT4_NUM_B2C(sbi, to_release);
 	while (num_clusters > 0) {
-		ext4_fsblk_t lblk;
 		lblk = (page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits)) +
 			((num_clusters - 1) << sbi->s_cluster_bits);
 		if (sbi->s_cluster_ratio == 1 ||
@@ -1502,9 +1524,15 @@ static void ext4_da_block_invalidatepages(struct mpage_da_data *mpd)
 	struct pagevec pvec;
 	struct inode *inode = mpd->inode;
 	struct address_space *mapping = inode->i_mapping;
+	ext4_lblk_t start, last;
 
 	index = mpd->first_page;
 	end   = mpd->next_page - 1;
+
+	start = index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
+	last = end << (PAGE_CACHE_SHIFT - inode->i_blkbits);
+	ext4_es_remove_extent(inode, start, last - start + 1);
+
 	while (index <= end) {
 		nr_pages = pagevec_lookup(&pvec, mapping, index, PAGEVEC_SIZE);
 		if (nr_pages == 0)
@@ -1816,6 +1844,10 @@ static int ext4_da_map_blocks(struct inode *inode, sector_t iblock,
 				goto out_unlock;
 		}
 
+		retval = ext4_es_insert_extent(inode, map->m_lblk, map->m_len);
+		if (retval)
+			goto out_unlock;
+
 		/* Clear EXT4_MAP_FROM_CLUSTER flag since its purpose is served
 		 * and it should not appear on the bh->b_state.
 		 */

fs/ext4/super.c

@@ -50,6 +50,7 @@
 #include "xattr.h"
 #include "acl.h"
 #include "mballoc.h"
+#include "ext4_extents.h"
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/ext4.h>
@@ -1033,6 +1034,7 @@ void ext4_clear_inode(struct inode *inode)
 	clear_inode(inode);
 	dquot_drop(inode);
 	ext4_discard_preallocations(inode);
+	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
 	if (EXT4_I(inode)->jinode) {
 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
 					       EXT4_I(inode)->jinode);
@@ -5296,9 +5298,14 @@ static int __init ext4_init_fs(void)
 		init_waitqueue_head(&ext4__ioend_wq[i]);
 	}
 
-	err = ext4_init_pageio();
+	err = ext4_init_es();
 	if (err)
 		return err;
+
+	err = ext4_init_pageio();
+	if (err)
+		goto out7;
+
 	err = ext4_init_system_zone();
 	if (err)
 		goto out6;
@@ -5348,6 +5355,9 @@ out5:
 	ext4_exit_system_zone();
 out6:
 	ext4_exit_pageio();
+out7:
+	ext4_exit_es();
+
 	return err;
 }