Merge branch 'wait_dev'

1 files changed, 35 insertions, 3 deletions

diff --git a/init b/init
index b0e2828..288f77b 100755
--- a/init
+++ b/init
@@ -114,6 +114,38 @@ function setup_encrypted {
 
 
 #
+# Waits up to a threshold (in seconds) for the specified path to appear as a
+# block device. A check for device presence occurs once per second.
+#
+# If the device appears within the threshold time, the function returns early
+# with error code 0 (all is well - no need to wait more).
+#
+# If the block device fails to appear within the threshold time, the function
+# returns code 2 (not found)
+#
+# @param dev     Path to the device to wait for
+# @param timeout Maximum time (in seconds) to wait for the device to appear
+#
+wait_dev() {
+  local dev=${1}
+  local timeout=${2}
+
+  local wait=0
+
+  while [ ${wait} -lt ${timeout} ]; do
+    # If the path exists as a block device, exit the wait loop
+    [ -b "${dev}" ] && return 0
+    # Increment the wait counter
+    wait=$(( wait + 1 ))
+    # Wait another second for the device to appear
+    sleep 1
+  done
+
+  return 2
+}
+
+
+#
 # Main function to keep the main operations code nicely separated from the
 # rest.
 #
@@ -140,11 +172,11 @@ function main {
 
   log "Root device: ${ROOTDEV}"
 
-  log "Waiting a few seconds for devices to settle."
-  sleep 2
+  log "Waiting up to 10 seconds for root device to appear."
+  wait_dev "${ROOTDEV}" 10
 
   # Drop to maintenance shell if root device does not exist.
-  if [[ ! -b ${ROOTDEV} ]]; then
+  if [[ $? -ne 0 ]]; then
     log "ERROR: Root device ${ROOTDEV} does not exist or can not be accessed."
     log "       Dropping to maintenance shell for troubleshooting."
     log "       (You may just need to wait longer for the root device)"