Merge pull request #10970 from xiexingguo/xxg-wip-honour-alloweio-flag

os/bluestore: honour allow-eio flag; use global compressor if possible

Reviewed-by: Sage Weil <sage@redhat.com>

src/os/bluestore/BlueStore.cc

@@ -3697,6 +3697,7 @@ int BlueStore::read(
   }
 
  out:
+  assert(allow_eio || r != -EIO);
   c->cache->trim(
     g_conf->bluestore_onode_cache_size,
     g_conf->bluestore_buffer_cache_size);
@@ -3847,14 +3848,19 @@ int BlueStore::_do_read(
     if (bptr->get_blob().has_flag(bluestore_blob_t::FLAG_COMPRESSED)) {
       bufferlist compressed_bl, raw_bl;
       IOContext ioc(NULL);   // FIXME?
-      bptr->get_blob().map(
+      r = bptr->get_blob().map(
 	0, bptr->get_blob().get_ondisk_length(),
 	[&](uint64_t offset, uint64_t length) {
 	  bufferlist t;
 	  int r = bdev->read(offset, length, &t, &ioc, false);
-	  assert(r == 0);
+	  if (r < 0)
+            return r;
 	  compressed_bl.claim_append(t);
+          return 0;
 	});
+      if (r < 0)
+        return r;
+
       if (_verify_csum(o, &bptr->get_blob(), 0, compressed_bl) < 0) {
 	return -EIO;
       }
@@ -3893,14 +3899,19 @@ int BlueStore::_do_read(
 	// read it
 	IOContext ioc(NULL);  // FIXME?
 	bufferlist bl;
-	bptr->get_blob().map(r_off, r_len,
+	r = bptr->get_blob().map(r_off, r_len,
 			     [&](uint64_t offset, uint64_t length) {
 	    bufferlist t;
 	    int r = bdev->read(offset, length, &t, &ioc, false);
-	    assert(r == 0);
+	    if (r < 0)
+              return r;
 	    bl.claim_append(t);
+            return 0;
 	  });
-	int r = _verify_csum(o, &bptr->get_blob(), r_off, bl);
+        if (r < 0)
+          return r;
+
+	r = _verify_csum(o, &bptr->get_blob(), r_off, bl);
 	if (r < 0) {
 	  return -EIO;
 	}
@@ -3958,12 +3969,14 @@ int BlueStore::_verify_csum(OnodeRef& o,
   if (r < 0) {
     if (r == -1) {
       vector<bluestore_pextent_t> pex;
-      blob->map(
+      int r = blob->map(
 	bad,
 	blob->get_csum_chunk_size(),
 	[&](uint64_t offset, uint64_t length) {
 	  pex.emplace_back(bluestore_pextent_t(offset, length));
+          return 0;
 	});
+      assert(r == 0);
       derr << __func__ << " bad " << blob->get_csum_type_string(blob->csum_type)
 	   << "/0x" << std::hex << blob->get_csum_chunk_size()
 	   << " checksum at blob offset 0x" << bad
@@ -3988,14 +4001,17 @@ int BlueStore::_decompress(bufferlist& source, bufferlist* result)
   bluestore_compression_header_t chdr;
   ::decode(chdr, i);
   string name = bluestore_blob_t::get_comp_alg_name(chdr.type);
-  CompressorRef compressor = Compressor::create(cct, name);
-  if (!compressor.get()) {
+  CompressorRef cp = compressor;
+  if (!cp || cp->get_type() != name)
+    cp = Compressor::create(cct, name);
+
+  if (!cp.get()) {
     // if compressor isn't available - error, because cannot return
     // decompressed data?
     derr << __func__ << " can't load decompressor " << chdr.type << dendl;
     r = -EIO;
   } else {
-    r = compressor->decompress(i, chdr.length, *result);
+    r = cp->decompress(i, chdr.length, *result);
     if (r < 0) {
       derr << __func__ << " decompression failed with exit code " << r << dendl;
       r = -EIO;
@@ -6167,11 +6183,13 @@ void BlueStore::_do_write_small(
       _buffer_cache_write(txc, b, b_off, padded,
 			  wctx->buffered ? 0 : Buffer::FLAG_NOCACHE);
 
-      b->get_blob().map(
+      int r = b->get_blob().map(
 	b_off, b_len,
 	[&](uint64_t offset, uint64_t length) {
 	  op->extents.emplace_back(bluestore_pextent_t(offset, length));
+          return 0;
 	});
+      assert(r == 0);
       if (b->get_blob().csum_type) {
 	txc->add_deferred_csum(o, blob, b_off, padded);
       }

src/os/bluestore/bluestore_types.h

@@ -458,8 +458,8 @@ struct bluestore_blob_t {
                uint64_t offset, uint64_t length,  uint64_t min_alloc_size,
                vector<bluestore_pextent_t> *r);
 
-  void map(uint64_t x_off, uint64_t x_len,
-	   std::function<void(uint64_t,uint64_t)> f) const {
+  int map(uint64_t x_off, uint64_t x_len,
+	   std::function<int(uint64_t,uint64_t)> f) const {
     auto p = extents.begin();
     assert(p != extents.end());
     while (x_off >= p->length) {
@@ -470,11 +470,14 @@ struct bluestore_blob_t {
     while (x_len > 0) {
       assert(p != extents.end());
       uint64_t l = MIN(p->length - x_off, x_len);
-      f(p->offset + x_off, l);
+      int r = f(p->offset + x_off, l);
+      if (r < 0)
+        return r;
       x_off = 0;
       x_len -= l;
       ++p;
     }
+    return 0;
   }
   void map_bl(uint64_t x_off,
 	      bufferlist& bl,