Reclaim extent block when removing non-root dir

When removing a directory, the extent block was not reclaimed properly.

This fix ensures that extent blocks for non-root directories are
reclaimed during removal. The root directory is excluded from this
process, as it serves as the mount point and cannot be removed.

The reclaim mechanism is designed to run when a directory is actually
removed, not just when it becomes empty.

close #65

Author: RoyWFHuang

inode.c

@@ -603,8 +603,6 @@ static int simplefs_unlink(struct inode *dir, struct dentry *dentry)
     if (!bh)
         goto clean_inode;
     file_block = (struct simplefs_file_ei_block *) bh->b_data;
-    if (S_ISDIR(inode->i_mode))
-        goto scrub;
 
     for (ei = 0; ei < SIMPLEFS_MAX_EXTENTS; ei++) {
         char *block;
@@ -627,7 +625,6 @@ static int simplefs_unlink(struct inode *dir, struct dentry *dentry)
         }
     }
 
-scrub:
     /* Scrub index block */
     memset(file_block, 0, SIMPLEFS_BLOCK_SIZE);
     mark_buffer_dirty(bh);

script/test.sh

@@ -1,5 +1,7 @@
 #!/usr/bin/env bash
 
+. script/test_large_file.sh
+
 SIMPLEFS_MOD=simplefs.ko
 IMAGE=$1
 IMAGESIZE=$2
@@ -47,13 +49,6 @@ dd if=/dev/zero of=$IMAGE bs=1M count=$IMAGESIZE status=none && \
 sudo mount -t simplefs -o loop $IMAGE test && \
 pushd test >/dev/null
 
-# mkdir
-test_op 'mkdir dir'
-test_op 'mkdir dir' # expected to fail
-
-# create file
-test_op 'touch file'
-
 # create 40920 files
 for ((i=0; i<=$MAXFILES; i++))
 do
@@ -98,6 +93,21 @@ do
     fi
 done
 find . -name 'file_[0-9]*.txt' | xargs sudo rm || { echo "Failed to delete files"; exit 1; }
+sync
+
+popd >/dev/null || { echo "popd failed"; exit 1; }
+ls test -laR
+rm test/* -rf
+nr_free_blk=$(($(dd if=$IMAGE bs=1 skip=28 count=4 2>/dev/null | hexdump -v -e '1/4 "0x%08x\n"')))
+echo "$nr_free_blk"
+pushd test >/dev/null || { echo "pushd failed"; exit 1; }
+
+# mkdir
+test_op 'mkdir dir'
+test_op 'mkdir dir' # expected to fail
+
+# create file
+test_op 'touch file'
 
 # hard link
 test_op 'ln file hdlink'
@@ -119,21 +129,11 @@ test_op 'echo abc > file'
 test $(cat file) = "abc" || echo "Failed to write"
 
 # file too large
-test_op 'dd if=/dev/zero of=file bs=1M count=12 status=none'
-filesize=$(sudo ls -lR  | grep -e "$F_MOD 2".*file | awk '{print $5}')
-test $filesize -le $MAXFILESIZE || echo "Failed, file size over the limit"
+test_too_large_file
 
 # Write the file size larger than BLOCK_SIZE
 # test serial to write
-test_op 'printf \"%.0s123456789\" {1..1600} > file.txt'
-count=$(awk '{count += gsub(/123456789/, "")} END {print count}' "file.txt")
-echo "test $count"
-test "$count" -eq 1600 || echo "Failed, file size not matching"
-# test block to write
-test_op 'cat file.txt > checkfile.txt'
-count=$(awk '{count += gsub(/123456789/, "")} END {print count}' "checkfile.txt")
-echo "test $count"
-test "$count" -eq 1600 || echo "Failed, file size not matching"
+test_file_size_larger_than_block_size
 
 # test remove symbolic link
 test_op 'ln -s file symlink_fake'
@@ -152,7 +152,13 @@ check_exist $S_MOD 1 symlink
 check_exist $F_MOD 1 symlink_fake
 check_exist $F_MOD 1 symlink_hard_fake
 
+# clean all files and directories
+test_op 'rm -rf ./*'
+
 sleep 1
 popd >/dev/null
 sudo umount test
 sudo rmmod simplefs
+
+af_nr_free_blk=$(($(dd if=$IMAGE bs=1 skip=28 count=4 2>/dev/null | hexdump -v -e '1/4 "0x%08x\n"')))
+test $nr_free_blk -eq $af_nr_free_blk || echo "Failed, some blocks are not be reclaimed"

script/test_large_file.sh

@@ -0,0 +1,20 @@
+# file too large
+test_too_large_file() {
+    test_op 'dd if=/dev/zero of=file bs=1M count=12 status=none'
+    filesize=$(sudo ls -lR  | grep -e "$F_MOD 2".*file | awk '{print $5}')
+    test $filesize -le $MAXFILESIZE || echo "Failed, file size over the limit"
+}
+
+# Write the file size larger than BLOCK_SIZE
+# test serial to write
+test_file_size_larger_than_block_size() {
+    test_op 'yes 123456789 | head -n 1600 | tr -d "\n" > file.txt'
+    count=$(awk '{count += gsub(/123456789/, "")} END {print count}' "file.txt")
+    echo "test $count"
+    test "$count" -eq 1600 || echo "Failed, file size not matching"
+    # test block to write
+    test_op 'cat file.txt > checkfile.txt'
+    count=$(awk '{count += gsub(/123456789/, "")} END {print count}' "checkfile.txt")
+    echo "test $count"
+    test "$count" -eq 1600 || echo "Failed, file size not matching"
+}