From 26b60474691ad4bdb91f61b667819e22aabc202f Mon Sep 17 00:00:00 2001 From: Pavel Zakharov Date: Wed, 17 Jul 2019 18:33:05 -0400 Subject: New service that waits on zvol links to be created MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The zfs-volume-wait.service scans existing zvols and waits for their links under /dev to be created. Any service that depends on zvol links to be there should add a dependency on zfs-volumes.target. By default, this target is not enabled. Reviewed-by: Fabian Grünbichler Reviewed-by: Antonio Russo Reviewed-by: Richard Laager Reviewed-by: loli10K Reviewed-by: John Gallagher Reviewed-by: George Wilson Reviewed-by: Brian Behlendorf Signed-off-by: Pavel Zakharov Closes #8975 --- cmd/Makefile.am | 2 +- cmd/zvol_wait/Makefile.am | 1 + cmd/zvol_wait/zvol_wait | 93 +++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 95 insertions(+), 1 deletion(-) create mode 100644 cmd/zvol_wait/Makefile.am create mode 100755 cmd/zvol_wait/zvol_wait (limited to 'cmd') diff --git a/cmd/Makefile.am b/cmd/Makefile.am index 0d990789b..88609e455 100644 --- a/cmd/Makefile.am +++ b/cmd/Makefile.am @@ -5,4 +5,4 @@ if USING_PYTHON SUBDIRS += arcstat arc_summary dbufstat endif -SUBDIRS += mount_zfs zed zvol_id +SUBDIRS += mount_zfs zed zvol_id zvol_wait diff --git a/cmd/zvol_wait/Makefile.am b/cmd/zvol_wait/Makefile.am new file mode 100644 index 000000000..564031c97 --- /dev/null +++ b/cmd/zvol_wait/Makefile.am @@ -0,0 +1 @@ +dist_bin_SCRIPTS = zvol_wait diff --git a/cmd/zvol_wait/zvol_wait b/cmd/zvol_wait/zvol_wait new file mode 100755 index 000000000..d512be41b --- /dev/null +++ b/cmd/zvol_wait/zvol_wait @@ -0,0 +1,93 @@ +#!/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 | while read -r zvol_line; do + name=$(echo "$zvol_line" | awk '{print $1}') + volmode=$(echo "$zvol_line" | awk '{print $2}') + # /dev links are not created for zvols with volmode = "none". + [ "$volmode" = "none" ] || 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 -- cgit v1.2.3