generic/020: add and use _attr_get_max()

In preparation for taking into account the attr name length when
calculating $MAX_ATTRVAL_SIZE, put the current logic in a
_attr_get_max() helper function and set local $max_attrval_size /
$max_attrs variables instead of using export.

Signed-off-by: David Disseldorp <ddiss@suse.de>
Reviewed-by: Eryu Guan <guaneryu@gmail.com>
Signed-off-by: Eryu Guan <guaneryu@gmail.com>

diff --git a/tests/generic/020 b/tests/generic/020
index c2c285f60d595a6c22def6d4cf28dbfceec4eceb..cbd3f227398b21f6b5898efb632f305b4c5466f7 100755 (executable)
--- a/tests/generic/020
+++ b/tests/generic/020
@@ -51,81 +51,89 @@ _attr_list()
     fi
 }
 
-# set maximum total attr space based on fs type
-case "$FSTYP" in
-xfs|udf|pvfs2|9p|ceph|nfs)
-       MAX_ATTRS=1000
-       ;;
-ext2|ext3|ext4)
-       # For 4k blocksizes, most of the attributes have an attr_name of
-       # "attribute_NN" which is 12, and "value_NN" which is 8.
-       # But for larger block sizes, we start having extended attributes of the
-       # form "attribute_NNN" or "attribute_NNNN", and "value_NNN" and
-       # "value_NNNN", which causes the round(len(..), 4) to jump up by 4
-       # bytes.  So round_up(len(attr_name, 4)) becomes 16 instead of 12, and
-       # round_up(len(value, 4)) becomes 12 instead of 8.
-       #
-       # For 64K blocksize the calculation becomes
-       #       max_attrs = (block_size - 32) / (16 + 12 + 16)
-       # or
-       #       max_attrs = (block_size - 32) / 44
-       #
-       # For 4K blocksize:-
-       #       max_attrs = (block_size - 32) / (16 + 8 + 12)
-       # or
-       #       max_attrs = (block_size - 32) / 36
-       #
-       # Note (for 4K bs) above are exact calculations for attrs of type
-       # attribute_NN with values of type value_NN.
-       # With above calculations, for 4k blocksize max_attrs becomes 112.
-       # This means we can have few attrs of type attribute_NNN with values of
-       # type value_NNN. To avoid/handle this we need to add extra 4 bytes of
-       # headroom.
-       #
-       # So for 4K, the calculations becomes:-
-       #       max_attrs = (block_size - 32) / (16 + 8 + 12 + 4)
-       # or
-       #       max_attrs = (block_size - 32) / 40
-       #
-       # Assume max ~1 block of attrs
-       BLOCK_SIZE=`_get_block_size $TEST_DIR`
-       if [ $BLOCK_SIZE -le 4096 ]; then
-               let MAX_ATTRS=$((($BLOCK_SIZE - 32) / (16 + 8 + 12 + 4)))
-       else
-               let MAX_ATTRS=$((($BLOCK_SIZE - 32) / (16 + 12 + 16 )))
-       fi
-       ;;
-*)
-       # Assume max ~1 block of attrs
-       BLOCK_SIZE=`_get_block_size $TEST_DIR`
-       # user.attribute_XXX="value.XXX" is about 32 bytes; leave some overhead
-       let MAX_ATTRS=$BLOCK_SIZE/40
-esac
-
-export MAX_ATTRS
-
-# Set max attr value size based on fs type
-case "$FSTYP" in
-xfs|udf|btrfs)
-       MAX_ATTRVAL_SIZE=64
-       ;;
-pvfs2)
-       MAX_ATTRVAL_SIZE=8192
-       ;;
-9p|ceph|nfs)
-       MAX_ATTRVAL_SIZE=65536
-       ;;
-bcachefs)
-       MAX_ATTRVAL_SIZE=1024
-       ;;
-*)
-       # Assume max ~1 block of attrs
-       BLOCK_SIZE=`_get_block_size $TEST_DIR`
-       # leave a little overhead
-       let MAX_ATTRVAL_SIZE=$BLOCK_SIZE-256
-esac
-
-export MAX_ATTRVAL_SIZE
+# set fs-specific max_attrs and max_attrval_size values. The parameter
+# @max_attrval_namelen is required for filesystems which take into account attr
+# name lengths (including namespace prefix) when determining limits.
+_attr_get_max()
+{
+       local max_attrval_namelen="$1"
+
+       # set maximum total attr space based on fs type
+       case "$FSTYP" in
+       xfs|udf|pvfs2|9p|ceph|nfs)
+               max_attrs=1000
+               ;;
+       ext2|ext3|ext4)
+               # For 4k blocksizes, most of the attributes have an attr_name of
+               # "attribute_NN" which is 12, and "value_NN" which is 8.
+               # But for larger block sizes, we start having extended
+               # attributes of the
+               # form "attribute_NNN" or "attribute_NNNN", and "value_NNN" and
+               # "value_NNNN", which causes the round(len(..), 4) to jump up by
+               # 4 bytes.  So round_up(len(attr_name, 4)) becomes 16 instead of
+               # 12, and round_up(len(value, 4)) becomes 12 instead of 8.
+               #
+               # For 64K blocksize the calculation becomes
+               #       max_attrs = (block_size - 32) / (16 + 12 + 16)
+               # or
+               #       max_attrs = (block_size - 32) / 44
+               #
+               # For 4K blocksize:-
+               #       max_attrs = (block_size - 32) / (16 + 8 + 12)
+               # or
+               #       max_attrs = (block_size - 32) / 36
+               #
+               # Note (for 4K bs) above are exact calculations for attrs of
+               # type attribute_NN with values of type value_NN.
+               # With above calculations, for 4k blocksize max_attrs becomes
+               # 112.
+               # This means we can have few attrs of type attribute_NNN with
+               # values of
+               # type value_NNN. To avoid/handle this we need to add extra 4
+               # bytes of headroom.
+               #
+               # So for 4K, the calculations becomes:-
+               #       max_attrs = (block_size - 32) / (16 + 8 + 12 + 4)
+               # or
+               #       max_attrs = (block_size - 32) / 40
+               #
+               # Assume max ~1 block of attrs
+               BLOCK_SIZE=`_get_block_size $TEST_DIR`
+               if [ $BLOCK_SIZE -le 4096 ]; then
+                       let max_attrs=$((($BLOCK_SIZE - 32) / (16 + 8 + 12 + 4)))
+               else
+                       let max_attrs=$((($BLOCK_SIZE - 32) / (16 + 12 + 16 )))
+               fi
+               ;;
+       *)
+               # Assume max ~1 block of attrs
+               BLOCK_SIZE=`_get_block_size $TEST_DIR`
+               # user.attribute_XXX="value.XXX" is about 32 bytes; leave some
+               # overhead
+               let max_attrs=$BLOCK_SIZE/40
+       esac
+
+       # Set max attr value size based on fs type
+       case "$FSTYP" in
+       xfs|udf|btrfs)
+               max_attrval_size=64
+               ;;
+       pvfs2)
+               max_attrval_size=8192
+               ;;
+       9p|ceph|nfs)
+               max_attrval_size=65536
+               ;;
+       bcachefs)
+               max_attrval_size=1024
+               ;;
+       *)
+               # Assume max ~1 block of attrs
+               BLOCK_SIZE=`_get_block_size $TEST_DIR`
+               # leave a little overhead
+               let max_attrval_size=$BLOCK_SIZE-256
+       esac
+}
 
 # real QA test starts here
 _supported_fs generic
@@ -161,10 +169,13 @@ echo "*** remove attribute"
 _attr -r fish $testfile
 _attr_list $testfile
 
+max_attrval_name="long_attr"   # add 5 for "user." prefix
+_attr_get_max "$(( 5 + ${#max_attrval_name} ))"
+
 echo "*** add lots of attributes"
 v=0
 
-while [ $v -lt $MAX_ATTRS ]
+while [ $v -lt $max_attrs ]
 do
     echo -n "value_$v" | attr -s "attribute_$v" $testfile >>$seqres.full
     if [ $? -ne 0 ]
@@ -185,11 +196,11 @@ _getfattr --absolute-names $testfile \
        /^[     ]*$/ { next }
         { l++ } 
        END {print "   *** " (l - 1) " attribute(s)" }' \
-    | sed s/$MAX_ATTRS/MAX_ATTRS/
+    | sed s/$max_attrs/MAX_ATTRS/
 
 echo "*** remove lots of attributes"
 v=0
-while [ $v -lt $MAX_ATTRS ]
+while [ $v -lt $max_attrs ]
 do
     if ! $ATTR_PROG -r "attribute_$v" $testfile >>$seqres.full
     then
@@ -203,12 +214,13 @@ done
 _attr_list $testfile
 
 echo "*** really long value"
-dd if=/dev/zero bs=1 count=$MAX_ATTRVAL_SIZE 2>/dev/null \
-    | _attr -s "long_attr" $testfile >/dev/null
+dd if=/dev/zero bs=1 count=$max_attrval_size 2>/dev/null \
+    | _attr -s "$max_attrval_name" $testfile >/dev/null
 
-OCTAL_SIZE=`echo "obase=8; $MAX_ATTRVAL_SIZE" | bc`
-_attr -q -g "long_attr" $testfile | od -t x1 | sed -e "s/^0*$OCTAL_SIZE$/ATTRSIZE/"    
-_attr -r "long_attr" $testfile >/dev/null
+OCTAL_SIZE=`echo "obase=8; $max_attrval_size" | bc`
+_attr -q -g "$max_attrval_name" $testfile | od -t x1 \
+    | sed -e "s/^0*$OCTAL_SIZE$/ATTRSIZE/"
+_attr -r "$max_attrval_name" $testfile >/dev/null
 
 echo "*** set/get/remove really long names (expect failure)"
 short="XXXXXXXXXX"