From: Dongsheng Yang <dongsheng.yang@easystack.cn>
Date: Thu, 3 Nov 2016 06:34:10 +0000 (-0400)
Subject: rbd: import: use read() instead of lseek() when from_stdin is true
X-Git-Tag: v12.0.1~342^2~1
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=fedf772ba1e84a7ee0296177dcaba6f3c6ebe263;p=ceph.git

rbd: import: use read() instead of lseek() when from_stdin is true

Signed-off-by: Dongsheng Yang <dongsheng.yang@easystack.cn>
---

diff --git a/src/tools/rbd/action/Export.cc b/src/tools/rbd/action/Export.cc
index f938590d3a28..485b0ad841da 100644
--- a/src/tools/rbd/action/Export.cc
+++ b/src/tools/rbd/action/Export.cc
@@ -375,7 +375,6 @@ static int do_export_v2(librbd::Image& image, librbd::image_info_t &info, int fd
 		        uint64_t period, int max_concurrent_ops, utils::ProgressContext &pc)
 {
   int r = 0;
-  size_t offset = 0;
   // header
   bufferlist bl;
   bl.append(utils::RBD_IMAGE_BANNER_V2);
@@ -424,9 +423,6 @@ static int do_export_v2(librbd::Image& image, librbd::image_info_t &info, int fd
   if (r < 0) {
     return r;
   }
-  offset += bl.length();
-
-  lseek(fd, offset, SEEK_SET);
 
   // header for snapshots
   bl.clear();
@@ -446,26 +442,22 @@ static int do_export_v2(librbd::Image& image, librbd::image_info_t &info, int fd
     return r;
   }
 
-  if (0 == diff_num) {
-    return r;
-  } else {
-    const char *last_snap = NULL;
-    for (size_t i = 0; i < snaps.size(); ++i) {
-      utils::snap_set(image, snaps[i].name.c_str());
-      r = do_export_diff_fd(image, last_snap, snaps[i].name.c_str(), false, fd, true, 2);
-      if (r < 0) {
-	return r;
-      }
-      pc.update_progress(i, snaps.size() + 1);
-      last_snap = snaps[i].name.c_str();
-    }
-    utils::snap_set(image, std::string(""));
-    r = do_export_diff_fd(image, last_snap, nullptr, false, fd, true, 2);
+  const char *last_snap = NULL;
+  for (size_t i = 0; i < snaps.size(); ++i) {
+    utils::snap_set(image, snaps[i].name.c_str());
+    r = do_export_diff_fd(image, last_snap, snaps[i].name.c_str(), false, fd, true, 2);
     if (r < 0) {
       return r;
     }
-    pc.update_progress(snaps.size() + 1, snaps.size() + 1);
+    pc.update_progress(i, snaps.size() + 1);
+    last_snap = snaps[i].name.c_str();
+  }
+  utils::snap_set(image, std::string(""));
+  r = do_export_diff_fd(image, last_snap, nullptr, false, fd, true, 2);
+  if (r < 0) {
+    return r;
   }
+  pc.update_progress(snaps.size() + 1, snaps.size() + 1);
   return r;
 }
 
@@ -492,7 +484,12 @@ static int do_export_v1(librbd::Image& image, librbd::image_info_t &info, int fd
   if (fd != 1) {
     if (r >= 0) {
       r = ftruncate(fd, file_size);
-      r = lseek(fd, file_size, SEEK_SET);
+      if (r < 0)
+	return r;
+
+      uint64_t chkret = lseek64(fd, file_size, SEEK_SET);
+      if (chkret != file_size)
+	r = errno;
     }
   }
   return r;
diff --git a/src/tools/rbd/action/Import.cc b/src/tools/rbd/action/Import.cc
index 0fa76f2f5c53..75c07c67d1aa 100644
--- a/src/tools/rbd/action/Import.cc
+++ b/src/tools/rbd/action/Import.cc
@@ -152,11 +152,22 @@ int do_import_diff_fd(librbd::Image &image, int fd,
       } else {
 	std::cerr << "unrecognized tag byte " << (int)tag
 		  << " in stream; aborting" << std::endl;
-	if (format == 2) {
-	  ::lseek(fd, length, SEEK_CUR);
+	if (from_stdin) {
+	  char buf[4096];
+	  uint64_t len = min(length, uint64_t(4096));
+	  while (len > 0) {
+	    r = safe_read_exact(fd, buf, len);
+	    if (r < 0)
+	      return r;
+	    length -= len;
+	    len = min(length, uint64_t(4096));
+	  }
 	} else {
-	  r = -EINVAL;
-	  goto done;
+	  off64_t offs = lseek64(fd, length, SEEK_CUR);
+	  if (offs < 0) {
+	    r = -errno;
+	    goto done;
+	  }
 	}
       }
     }
@@ -409,7 +420,23 @@ static int do_import_header(int fd, int import_format, uint64_t &size, librbd::I
 	}
       } else {
 	std::cerr << "rbd: invalid tag in image properties zone: " << tag << "Skip it." << std::endl;
-	::lseek(fd, length, SEEK_CUR);
+	if (fd == STDIN_FILENO) {
+	  // read the appending data out to skip this tag.
+	  char buf[4096];
+	  uint64_t len = min(length, uint64_t(4096));
+	  while (len > 0) {
+	    r = safe_read_exact(fd, buf, len);
+	    if (r < 0)
+	      return r;
+	    length -= len;
+	    len = min(length, uint64_t(4096));
+	  }
+	} else {
+	  // lseek to skip this tag
+	  off64_t offs = lseek64(fd, length, SEEK_CUR);
+	  if (offs < 0)
+	    return -errno;
+	}
       }
     }
   }