--- /dev/null
+#!/bin/bash
+
+set -ex
+shopt -s nullglob # fns glob expansion in expect_alloc_hint_eq()
+
+#
+# Helpers
+#
+
+function get_xml_val() {
+ local xml="$1"
+ local tag="$2"
+
+ local regex=".*<${tag}>(.*)</${tag}>.*"
+ if [[ ! "${xml}" =~ ${regex} ]]; then
+ echo "'${xml}' xml doesn't match '${tag}' tag regex" >&2
+ return 2
+ fi
+
+ echo "${BASH_REMATCH[1]}"
+}
+
+function get_conf_val() {
+ set -e
+
+ local entity="$1"
+ local option="$2"
+
+ local val
+ val="$(sudo ceph daemon "${entity}" config get --format=xml "${option}")"
+ val="$(get_xml_val "${val}" "${option}")"
+
+ echo "${val}"
+}
+
+function setup_osd_data() {
+ for (( i = 0 ; i < "${NUM_OSDS}" ; i++ )); do
+ OSD_DATA[i]="$(get_conf_val "osd.$i" "osd_data")"
+ done
+}
+
+function setup_pgid() {
+ local poolname="$1"
+ local objname="$2"
+
+ local pgid
+ pgid="$(ceph osd map "${poolname}" "${objname}" --format=xml)"
+ pgid="$(get_xml_val "${pgid}" "pgid")"
+
+ PGID="${pgid}"
+}
+
+function expect_alloc_hint_eq() {
+ local expected_extsize="$1"
+
+ for (( i = 0 ; i < "${NUM_OSDS}" ; i++ )); do
+ # e.g., .../25.6_head/foo__head_7FC1F406__19
+ # .../26.bs1_head/bar__head_EFE6384B__1a_ffffffffffffffff_1
+ local fns=(${OSD_DATA[i]}/current/${PGID}*_head/${OBJ}_*)
+ local count="${#fns[@]}"
+ if [ "${count}" -ne 1 ]; then
+ echo "bad fns count: ${count}" >&2
+ return 2
+ fi
+
+ local extsize
+ extsize="$(sudo xfs_io -c extsize "${fns[0]}")"
+ local extsize_regex="^\[(.*)\] ${fns[0]}$"
+ if [[ ! "${extsize}" =~ ${extsize_regex} ]]; then
+ echo "extsize doesn't match extsize_regex: ${extsize}" >&2
+ return 2
+ fi
+ extsize="${BASH_REMATCH[1]}"
+
+ if [ "${extsize}" -ne "${expected_extsize}" ]; then
+ echo "FAIL: alloc_hint: actual ${extsize}, expected ${expected_extsize}" >&2
+ return 1
+ fi
+ done
+}
+
+#
+# Global setup
+#
+
+EC_K="2"
+EC_M="1"
+NUM_OSDS="$((EC_K + EC_M))"
+
+NUM_PG="12"
+NUM_PGP="${NUM_PG}"
+
+LOW_CAP="$(get_conf_val "osd.0" "filestore_max_alloc_hint_size")"
+HIGH_CAP="$((LOW_CAP * 10))" # 10M, assuming 1M default cap
+SMALL_HINT="$((LOW_CAP / 4))" # 256K, assuming 1M default cap
+BIG_HINT="$((LOW_CAP * 6))" # 6M, assuming 1M default cap
+
+setup_osd_data
+
+#
+# ReplicatedBackend tests
+#
+
+POOL="alloc_hint-rep"
+ceph osd pool create "${POOL}" "${NUM_PG}"
+ceph osd pool set "${POOL}" size "${NUM_OSDS}" # just in case
+
+OBJ="foo"
+setup_pgid "${POOL}" "${OBJ}"
+rados -p "${POOL}" create "${OBJ}"
+
+# Empty object, SMALL_HINT - expect SMALL_HINT
+rados -p "${POOL}" set-alloc-hint "${OBJ}" "${SMALL_HINT}" "${SMALL_HINT}"
+expect_alloc_hint_eq "${SMALL_HINT}"
+
+# Try changing to BIG_HINT (1) - expect LOW_CAP (BIG_HINT > LOW_CAP)
+rados -p "${POOL}" set-alloc-hint "${OBJ}" "${BIG_HINT}" "${BIG_HINT}"
+expect_alloc_hint_eq "${LOW_CAP}"
+
+# Bump the cap to HIGH_CAP
+ceph tell 'osd.*' injectargs "--filestore_max_alloc_hint_size ${HIGH_CAP}"
+
+# Try changing to BIG_HINT (2) - expect BIG_HINT (BIG_HINT < HIGH_CAP)
+rados -p "${POOL}" set-alloc-hint "${OBJ}" "${BIG_HINT}" "${BIG_HINT}"
+expect_alloc_hint_eq "${BIG_HINT}"
+
+ceph tell 'osd.*' injectargs "--filestore_max_alloc_hint_size ${LOW_CAP}"
+
+# Populate object with some data
+rados -p "${POOL}" put "${OBJ}" /etc/passwd
+
+# Try changing back to SMALL_HINT - expect BIG_HINT (non-empty object)
+rados -p "${POOL}" set-alloc-hint "${OBJ}" "${SMALL_HINT}" "${SMALL_HINT}"
+expect_alloc_hint_eq "${BIG_HINT}"
+
+OBJ="bar"
+setup_pgid "${POOL}" "${OBJ}"
+
+# Non-existent object, SMALL_HINT - expect SMALL_HINT (object creation)
+rados -p "${POOL}" set-alloc-hint "${OBJ}" "${SMALL_HINT}" "${SMALL_HINT}"
+expect_alloc_hint_eq "${SMALL_HINT}"
+
+ceph osd pool delete "${POOL}" "${POOL}" --yes-i-really-really-mean-it
+
+#
+# ECBackend tests
+#
+
+POOL="alloc_hint-ec"
+RULE="ecruleset"
+ceph osd crush rule create-erasure "${RULE}" erasure-code-k="${EC_K}" erasure-code-m="${EC_M}" erasure-code-ruleset-failure-domain=osd
+ceph osd pool create "${POOL}" "${NUM_PG}" "${NUM_PGP}" erasure crush_ruleset="${RULE}" erasure-code-k="${EC_K}" erasure-code-m="${EC_M}" erasure-code-ruleset-failure-domain=osd
+
+OBJ="baz"
+setup_pgid "${POOL}" "${OBJ}"
+rados -p "${POOL}" create "${OBJ}"
+
+# Empty object, SMALL_HINT - expect scaled-down SMALL_HINT
+rados -p "${POOL}" set-alloc-hint "${OBJ}" "${SMALL_HINT}" "${SMALL_HINT}"
+expect_alloc_hint_eq "$((SMALL_HINT / EC_K))"
+
+ceph osd pool delete "${POOL}" "${POOL}" --yes-i-really-really-mean-it
+
+#
+# Global teardown
+#
+
+echo "OK"