ext4: add a hole extent entry in cache after punch

In order to cache hole extents in the extent status tree and keep the
hole length as long as possible, re-add a hole entry to the cache just
after punching a hole.

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20240127015825.1608160-5-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index b040337..af205b4 100644 (file)
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4007,12 +4007,12 @@ int ext4_punch_hole(struct file *file, loff_t offset, loff_t length)
 
        /* If there are blocks to remove, do it */
        if (stop_block > first_block) {
+               ext4_lblk_t hole_len = stop_block - first_block;
 
                down_write(&EXT4_I(inode)->i_data_sem);
                ext4_discard_preallocations(inode);
 
-               ext4_es_remove_extent(inode, first_block,
-                                     stop_block - first_block);
+               ext4_es_remove_extent(inode, first_block, hole_len);
 
                if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
                        ret = ext4_ext_remove_space(inode, first_block,
@@ -4021,6 +4021,8 @@ int ext4_punch_hole(struct file *file, loff_t offset, loff_t length)
                        ret = ext4_ind_remove_space(handle, inode, first_block,
                                                    stop_block);
 
+               ext4_es_insert_extent(inode, first_block, hole_len, ~0,
+                                     EXTENT_STATUS_HOLE);
                up_write(&EXT4_I(inode)->i_data_sem);
        }
        ext4_fc_track_range(handle, inode, first_block, stop_block);