zfs-builds-mm/zfs-0.8.2/cmd/zvol_wait/zvol_wait
2019-10-24 23:13:56 +02:00

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#!/bin/sh
count_zvols() {
if [ -z "$zvols" ]; then
echo 0
else
echo "$zvols" | wc -l
fi
}
filter_out_zvols_with_links() {
while read -r zvol; do
if [ ! -L "/dev/zvol/$zvol" ]; then
echo "$zvol"
fi
done
}
filter_out_deleted_zvols() {
while read -r zvol; do
if zfs list "$zvol" >/dev/null 2>&1; then
echo "$zvol"
fi
done
}
list_zvols() {
zfs list -t volume -H -o name,volmode,receive_resume_token |
while read -r zvol_line; do
name=$(echo "$zvol_line" | awk '{print $1}')
volmode=$(echo "$zvol_line" | awk '{print $2}')
token=$(echo "$zvol_line" | awk '{print $3}')
#
# /dev links are not created for zvols with volmode = "none".
#
[ "$volmode" = "none" ] && continue
#
# We also also ignore partially received zvols if it is
# not an incremental receive, as those won't even have a block
# device minor node created yet.
#
if [ "$token" != "-" ]; then
#
# Incremental receives create an invisible clone that
# is not automatically displayed by zfs list.
#
if ! zfs list "$name/%recv" >/dev/null 2>&1; then
continue
fi
fi
echo "$name"
done
}
zvols=$(list_zvols)
zvols_count=$(count_zvols)
if [ "$zvols_count" -eq 0 ]; then
echo "No zvols found, nothing to do."
exit 0
fi
echo "Testing $zvols_count zvol links"
outer_loop=0
while [ "$outer_loop" -lt 20 ]; do
outer_loop=$((outer_loop + 1))
old_zvols_count=$(count_zvols)
inner_loop=0
while [ "$inner_loop" -lt 30 ]; do
inner_loop=$((inner_loop + 1))
zvols="$(echo "$zvols" | filter_out_zvols_with_links)"
zvols_count=$(count_zvols)
if [ "$zvols_count" -eq 0 ]; then
echo "All zvol links are now present."
exit 0
fi
sleep 1
done
echo "Still waiting on $zvols_count zvol links ..."
#
# Although zvols should normally not be deleted at boot time,
# if that is the case then their links will be missing and
# we would stall.
#
if [ "$old_zvols_count" -eq "$zvols_count" ]; then
echo "No progress since last loop."
echo "Checking if any zvols were deleted."
zvols=$(echo "$zvols" | filter_out_deleted_zvols)
zvols_count=$(count_zvols)
if [ "$old_zvols_count" -ne "$zvols_count" ]; then
echo "$((old_zvols_count - zvols_count)) zvol(s) deleted."
fi
if [ "$zvols_count" -ne 0 ]; then
echo "Remaining zvols:"
echo "$zvols"
else
echo "All zvol links are now present."
exit 0
fi
fi
done
echo "Timed out waiting on zvol links"
exit 1