ext4: update delalloc data reserve spcae in ext4_es_insert_extent()

Now that we update data reserved space for delalloc after allocating
new blocks in ext4_{ind|ext}_map_blocks(), and if bigalloc feature is
enabled, we also need to query the extents_status tree to calculate the
exact reserved clusters. This is complicated now and it appears that
it's better to do this job in ext4_es_insert_extent(), because
__es_remove_extent() have already count delalloc blocks when removing
delalloc extents and __revise_pending() return new adding pending count,
we could update the reserved blocks easily in ext4_es_insert_extent().

We direct reduce the reserved cluster count when replacing a delalloc
extent. However, thers are two special cases need to concern about the
quota claiming when doing direct block allocation (e.g. from fallocate).

A),
fallocate a range that covers a delalloc extent but start with
non-delayed allocated blocks, e.g. a hole.

  hhhhhhh+ddddddd+ddddddd
  ^^^^^^^^^^^^^^^^^^^^^^^  fallocate this range

Current ext4_map_blocks() can't always trim the extent since it may
release i_data_sem before calling ext4_map_create_blocks() and raced by
another delayed allocation. Hence the EXT4_GET_BLOCKS_DELALLOC_RESERVE
may not set even when we are replacing a delalloc extent, without this
flag set, the quota has already been claimed by ext4_mb_new_blocks(), so
we should release the quota reservations instead of claim them again.

B),
bigalloc feature is enabled, fallocate a range that contains non-delayed
allocated blocks.

  |<         one cluster       >|
  hhhhhhh+hhhhhhh+hhhhhhh+ddddddd
  ^^^^^^^  fallocate this range

This case is similar to above case, the EXT4_GET_BLOCKS_DELALLOC_RESERVE
flag is also not set.

Hence we should release the quota reservations if we replace a delalloc
extent but without EXT4_GET_BLOCKS_DELALLOC_RESERVE set.

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://patch.msgid.link/20240813123452.2824659-7-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

1 files changed, 0 insertions, 37 deletions

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 671dacd7c873..db8f9d79477c 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -4358,43 +4358,6 @@ got_allocated_blocks:
 	}
 
 	/*
-	 * Reduce the reserved cluster count to reflect successful deferred
-	 * allocation of delayed allocated clusters or direct allocation of
-	 * clusters discovered to be delayed allocated.  Once allocated, a
-	 * cluster is not included in the reserved count.
-	 */
-	if (test_opt(inode->i_sb, DELALLOC) && allocated_clusters) {
-		if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
-			/*
-			 * When allocating delayed allocated clusters, simply
-			 * reduce the reserved cluster count and claim quota
-			 */
-			ext4_da_update_reserve_space(inode, allocated_clusters,
-							1);
-		} else {
-			ext4_lblk_t lblk, len;
-			unsigned int n;
-
-			/*
-			 * When allocating non-delayed allocated clusters
-			 * (from fallocate, filemap, DIO, or clusters
-			 * allocated when delalloc has been disabled by
-			 * ext4_nonda_switch), reduce the reserved cluster
-			 * count by the number of allocated clusters that
-			 * have previously been delayed allocated.  Quota
-			 * has been claimed by ext4_mb_new_blocks() above,
-			 * so release the quota reservations made for any
-			 * previously delayed allocated clusters.
-			 */
-			lblk = EXT4_LBLK_CMASK(sbi, map->m_lblk);
-			len = allocated_clusters << sbi->s_cluster_bits;
-			n = ext4_es_delayed_clu(inode, lblk, len);
-			if (n > 0)
-				ext4_da_update_reserve_space(inode, (int) n, 0);
-		}
-	}
-
-	/*
 	 * Cache the extent and update transaction to commit on fdatasync only
 	 * when it is _not_ an unwritten extent.
 	 */