From 6d307d5391ba58cf3d058a97e6aa7b6a68f63399 Mon Sep 17 00:00:00 2001
From: Vitaliy Filippov <vitalif@yourcmc.ru>
Date: Sun, 26 Sep 2021 11:32:42 +0300
Subject: [PATCH] Ignore "readonly" flag when merging snapshots

---
 src/cli_merge.cpp      |  2 ++
 src/cluster_client.cpp | 17 ++++++++++-------
 src/cluster_client.h   |  5 ++++-
 3 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/src/cli_merge.cpp b/src/cli_merge.cpp
index 50066d46e..4d2649e70 100644
--- a/src/cli_merge.cpp
+++ b/src/cli_merge.cpp
@@ -458,6 +458,7 @@ struct snap_merger_t
         subop->offset = rwo->offset+start;
         subop->len = end-start;
         subop->version = version;
+        subop->flags = OSD_OP_IGNORE_READONLY;
         subop->iov.push_back(rwo->buf+start, end-start);
         subop->callback = [this, rwo](cluster_op_t *subop)
         {
@@ -493,6 +494,7 @@ struct snap_merger_t
         subop->inode = inode_num;
         subop->offset = offset;
         subop->len = 0;
+        subop->flags = OSD_OP_IGNORE_READONLY;
         subop->callback = [this](cluster_op_t *subop)
         {
             if (subop->retval != 0)
diff --git a/src/cluster_client.cpp b/src/cluster_client.cpp
index b6e077eed..45688c246 100644
--- a/src/cluster_client.cpp
+++ b/src/cluster_client.cpp
@@ -12,7 +12,7 @@
 #define CACHE_DIRTY 1
 #define CACHE_FLUSHING 2
 #define CACHE_REPEATING 3
-#define OP_FLUSH_BUFFER 2
+#define OP_FLUSH_BUFFER 0x02
 
 cluster_client_t::cluster_client_t(ring_loop_t *ringloop, timerfd_manager_t *tfd, json11::Json & config)
 {
@@ -559,7 +559,7 @@ void cluster_client_t::flush_buffer(const object_id & oid, cluster_buffer_t *wr)
 {
     wr->state = CACHE_REPEATING;
     cluster_op_t *op = new cluster_op_t;
-    op->flags = OP_FLUSH_BUFFER;
+    op->flags = OSD_OP_IGNORE_READONLY|OP_FLUSH_BUFFER;
     op->opcode = OSD_OP_WRITE;
     op->cur_inode = op->inode = oid.inode;
     op->offset = oid.stripe;
@@ -620,12 +620,15 @@ resume_0:
     }
     if (op->opcode == OSD_OP_WRITE || op->opcode == OSD_OP_DELETE)
     {
-        auto ino_it = st_cli.inode_config.find(op->inode);
-        if (ino_it != st_cli.inode_config.end() && ino_it->second.readonly)
+        if (!(op->flags & OSD_OP_IGNORE_READONLY))
         {
-            op->retval = -EINVAL;
-            erase_op(op);
-            return 1;
+            auto ino_it = st_cli.inode_config.find(op->inode);
+            if (ino_it != st_cli.inode_config.end() && ino_it->second.readonly)
+            {
+                op->retval = -EINVAL;
+                erase_op(op);
+                return 1;
+            }
         }
         if (op->opcode == OSD_OP_WRITE && !immediate_commit && !(op->flags & OP_FLUSH_BUFFER))
         {
diff --git a/src/cluster_client.h b/src/cluster_client.h
index 08b543d76..77b1b63d1 100644
--- a/src/cluster_client.h
+++ b/src/cluster_client.h
@@ -14,6 +14,8 @@
 #define INODE_LIST_HAS_UNSTABLE 2
 #define OSD_OP_READ_BITMAP OSD_OP_SEC_READ_BMP
 
+#define OSD_OP_IGNORE_READONLY 0x08
+
 struct cluster_op_t;
 
 struct cluster_op_part_t
@@ -37,6 +39,8 @@ struct cluster_op_t
     // for reads and writes within a single object (stripe),
     // reads can return current version and writes can use "CAS" semantics
     uint64_t version = 0;
+    // now only OSD_OP_IGNORE_READONLY is supported
+    uint64_t flags = 0;
     int retval;
     osd_op_buf_list_t iov;
     // READ and READ_BITMAP return the bitmap here
@@ -44,7 +48,6 @@ struct cluster_op_t
     std::function<void(cluster_op_t*)> callback;
     ~cluster_op_t();
 protected:
-    uint64_t flags = 0;
     int state = 0;
     uint64_t cur_inode; // for snapshot reads
     void *buf = NULL;