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>

1 files changed, 35 insertions, 3 deletions

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index f84bfd6d1867..1e92349272e0 100644
--- a/fs/ext4/inode.c
+++ b/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.
                  */