mon: add proxy to cache tier options

When we set the proxy mode to remove a writeback cache according to
the ceph official documentation an error occurred:

[root@controller-1 root]# ceph osd tier cache-mode cachepool proxy
Invalid command: proxy not in writeback|readproxy|readonly|none
osd tier cache-mode writeback|readproxy|readonly|none [--yes-i-really-mean-it]:
specify the caching mode for cache tier

According to the description of the official website document: since
a writeback cache may have modified data, you must take steps to ensure
that you do not lose any recent changes to objects in the cache before
you disable and remove it. Change the cache mode to proxy so that new and
modified objects will flush to the backing storage pool.

Fixes: https://tracker.ceph.com/issues/54576
Signed-off-by: tan changzhi <544463199@qq.com>
(cherry picked from commit 77ad5a8)

doc/man/8/ceph.rst

@@ -1314,7 +1314,7 @@ Subcommand ``cache-mode`` specifies the caching mode for cache tier <pool>.
 
 Usage::
 
-	ceph osd tier cache-mode <poolname> writeback|readproxy|readonly|none
+	ceph osd tier cache-mode <poolname> writeback|proxy|readproxy|readonly|none
 
 Subcommand ``remove`` removes the tier <tierpool> (the second one) from base pool
 <pool> (the first one).

qa/workunits/cephtool/test.sh

@@ -350,28 +350,29 @@ function test_tiering_1()
   ceph osd pool ls detail -f json | jq '.[] | select(.pool_name == "slow2") | .application_metadata["rados"]' | grep '{}'
   ceph osd pool ls detail -f json | jq '.[] | select(.pool_name == "cache") | .application_metadata["rados"]' | grep '{}'
   ceph osd pool ls detail -f json | jq '.[] | select(.pool_name == "cache2") | .application_metadata["rados"]' | grep '{}'
-  # forward and proxy are removed/deprecated
+  # forward is removed/deprecated
   expect_false ceph osd tier cache-mode cache forward
   expect_false ceph osd tier cache-mode cache forward --yes-i-really-mean-it
-  expect_false ceph osd tier cache-mode cache proxy
-  expect_false ceph osd tier cache-mode cache proxy --yes-i-really-mean-it
   # test some state transitions
   ceph osd tier cache-mode cache writeback
   expect_false ceph osd tier cache-mode cache readonly
   expect_false ceph osd tier cache-mode cache readonly --yes-i-really-mean-it
+  ceph osd tier cache-mode cache proxy
   ceph osd tier cache-mode cache readproxy
   ceph osd tier cache-mode cache none
   ceph osd tier cache-mode cache readonly --yes-i-really-mean-it
   ceph osd tier cache-mode cache none
   ceph osd tier cache-mode cache writeback
+  ceph osd tier cache-mode cache proxy
+  ceph osd tier cache-mode cache writeback
   expect_false ceph osd tier cache-mode cache none
   expect_false ceph osd tier cache-mode cache readonly --yes-i-really-mean-it
   # test with dirty objects in the tier pool
   # tier pool currently set to 'writeback'
   rados -p cache put /etc/passwd /etc/passwd
   flush_pg_stats
   # 1 dirty object in pool 'cache'
-  ceph osd tier cache-mode cache readproxy
+  ceph osd tier cache-mode cache proxy
   expect_false ceph osd tier cache-mode cache none
   expect_false ceph osd tier cache-mode cache readonly --yes-i-really-mean-it
   ceph osd tier cache-mode cache writeback
@@ -380,7 +381,7 @@ function test_tiering_1()
   rados -p cache cache-flush-evict-all
   flush_pg_stats
   # no dirty objects in pool 'cache'
-  ceph osd tier cache-mode cache readproxy
+  ceph osd tier cache-mode cache proxy
   ceph osd tier cache-mode cache none
   ceph osd tier cache-mode cache readonly --yes-i-really-mean-it
   TRIES=0
@@ -1113,7 +1114,7 @@ function test_mon_mds()
 
   # Removing tier should be permitted because the underlying pool is
   # replicated (#11504 case)
-  ceph osd tier cache-mode mds-tier readproxy
+  ceph osd tier cache-mode mds-tier proxy
   ceph osd tier remove-overlay fs_metadata
   ceph osd tier remove fs_metadata mds-tier
   ceph osd pool delete mds-tier mds-tier --yes-i-really-really-mean-it

src/mon/MonCommands.h

@@ -1199,7 +1199,7 @@ COMMAND_WITH_FLAG("osd tier remove "
     FLAG(DEPRECATED))
 COMMAND("osd tier cache-mode "
 	"name=pool,type=CephPoolname "
-	"name=mode,type=CephChoices,strings=writeback|readproxy|readonly|none "
+	"name=mode,type=CephChoices,strings=writeback|proxy|readproxy|readonly|none "
 	"name=yes_i_really_mean_it,type=CephBool,req=false",
 	"specify the caching mode for cache tier <pool>", "osd", "rw")
 COMMAND("osd tier set-overlay "

src/mon/OSDMonitor.cc

@@ -13533,6 +13533,8 @@ bool OSDMonitor::prepare_command_impl(MonOpRequestRef op,
       ss << "unable to set cache-mode '" << pg_pool_t::get_cache_mode_name(mode)
          << "' on a '" << pg_pool_t::get_cache_mode_name(p->cache_mode)
          << "' pool; only '"
+         << pg_pool_t::get_cache_mode_name(pg_pool_t::CACHEMODE_PROXY)
+         << "','"
          << pg_pool_t::get_cache_mode_name(pg_pool_t::CACHEMODE_READPROXY)
         << "' allowed.";
       err = -EINVAL;