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Eric Blake

2019-Apr-23 19:06 UTC

[Libguestfs] [nbdkit PATCH 0/4] Start using cleanup macros in filters/plugins

There's more that can be done (in particular, use of CLEANUP_FREE),
but this is enough to at least see if I'm on the right track.

I couldn't figure out an obvious difference between common/include and
common/utils, but it looks like the former is for things that are
inlineable via .h only, while the latter is when you need to link in
a convenience library, so this landed in the latter.

Eric Blake (4):
  cleanup: Move cleanup.c to common
  filters: Utilize CLEANUP_EXTENTS_FREE
  filters: Utilize ACQUIRE_LOCK_FOR_CURRENT_SCOPE
  plugins: Utilize ACQUIRE_LOCK_FOR_CURRENT_SCOPE

 common/utils/cleanup.h             | 48 ++++++++++++++++++++++++++++++
 server/internal.h                  | 12 +-------
 {server => common/utils}/cleanup.c |  5 ++--
 filters/log/log.c                  | 10 +++----
 filters/offset/offset.c            | 13 ++++----
 filters/partition/partition.c      | 12 +++-----
 filters/readahead/readahead.c      | 15 ++++------
 filters/truncate/truncate.c        | 12 +++-----
 plugins/data/data.c                | 26 +++++-----------
 plugins/file/file.c                | 18 ++++-------
 plugins/memory/memory.c            | 26 +++++-----------
 plugins/nbd/nbd.c                  |  4 +--
 common/utils/Makefile.am           |  4 ++-
 filters/log/Makefile.am            |  5 +++-
 filters/offset/Makefile.am         |  5 +++-
 filters/partition/Makefile.am      |  5 +++-
 filters/readahead/Makefile.am      |  5 +++-
 filters/truncate/Makefile.am       |  5 +++-
 plugins/data/Makefile.am           |  4 ++-
 plugins/file/Makefile.am           |  5 +++-
 plugins/memory/Makefile.am         |  6 ++--
 plugins/nbd/Makefile.am            |  4 ++-
 server/Makefile.am                 |  7 +++--
 23 files changed, 137 insertions(+), 119 deletions(-)
 create mode 100644 common/utils/cleanup.h
 rename {server => common/utils}/cleanup.c (96%)

-- 
2.20.1

Eric Blake

2019-Apr-23 19:06 UTC

head link

[Libguestfs] [nbdkit PATCH 1/4] cleanup: Move cleanup.c to common

The CLEANUP_FREE macro and friends can be useful to filters and
in-tree plugins; as such, move them to common/ so more than just the
server/ code can take advantage of our compiler magic.

Signed-off-by: Eric Blake <eblake@redhat.com>
---
 common/utils/cleanup.h             | 48 ++++++++++++++++++++++++++++++
 server/internal.h                  | 12 +-------
 {server => common/utils}/cleanup.c |  5 ++--
 common/utils/Makefile.am           |  4 ++-
 server/Makefile.am                 |  7 +++--
 5 files changed, 58 insertions(+), 18 deletions(-)
 create mode 100644 common/utils/cleanup.h
 rename {server => common/utils}/cleanup.c (96%)

diff --git a/common/utils/cleanup.h b/common/utils/cleanup.h
new file mode 100644
index 0000000..e6e6140
--- /dev/null
+++ b/common/utils/cleanup.h
@@ -0,0 +1,48 @@
+/* nbdkit
+ * Copyright (C) 2013-2019 Red Hat Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * * Neither the name of Red Hat nor the names of its contributors may be
+ * used to endorse or promote products derived from this software without
+ * specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS
IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+ * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef NBDKIT_CLEANUP_H
+#define NBDKIT_CLEANUP_H
+
+#include <pthread.h>
+
+extern void cleanup_free (void *ptr);
+#define CLEANUP_FREE __attribute__((cleanup (cleanup_free)))
+extern void cleanup_extents_free (void *ptr);
+#define CLEANUP_EXTENTS_FREE __attribute__((cleanup (cleanup_extents_free)))
+extern void cleanup_unlock (pthread_mutex_t **ptr);
+#define CLEANUP_UNLOCK __attribute__((cleanup (cleanup_unlock)))
+#define ACQUIRE_LOCK_FOR_CURRENT_SCOPE(mutex) \
+  CLEANUP_UNLOCK pthread_mutex_t *_lock = mutex; \
+  pthread_mutex_lock (_lock)
+
+#endif /* NBDKIT_CLEANUP_H */
diff --git a/server/internal.h b/server/internal.h
index 817f022..67fccfc 100644
--- a/server/internal.h
+++ b/server/internal.h
@@ -42,6 +42,7 @@
 #define NBDKIT_API_VERSION 2
 #include "nbdkit-plugin.h"
 #include "nbdkit-filter.h"
+#include "cleanup.h"

 #ifdef __APPLE__
 #define UNIX_PATH_MAX 104
@@ -135,17 +136,6 @@ extern unsigned int get_socket_activation (void);
 /* usergroup.c */
 extern void change_user (void);

-/* cleanup.c */
-extern void cleanup_free (void *ptr);
-#define CLEANUP_FREE __attribute__((cleanup (cleanup_free)))
-extern void cleanup_extents_free (void *ptr);
-#define CLEANUP_EXTENTS_FREE __attribute__((cleanup (cleanup_extents_free)))
-extern void cleanup_unlock (pthread_mutex_t **ptr);
-#define CLEANUP_UNLOCK __attribute__((cleanup (cleanup_unlock)))
-#define ACQUIRE_LOCK_FOR_CURRENT_SCOPE(mutex) \
-  CLEANUP_UNLOCK pthread_mutex_t *_lock = mutex; \
-  pthread_mutex_lock (_lock)
-
 /* connections.c */
 struct connection;

diff --git a/server/cleanup.c b/common/utils/cleanup.c
similarity index 96%
rename from server/cleanup.c
rename to common/utils/cleanup.c
index 292f1ce..196d910 100644
--- a/server/cleanup.c
+++ b/common/utils/cleanup.c
@@ -34,10 +34,9 @@

 #include <stdio.h>
 #include <stdlib.h>
-#include <stdarg.h>
-#include <string.h>

-#include "internal.h"
+#include "cleanup.h"
+#include "nbdkit-filter.h"

 void
 cleanup_free (void *ptr)
diff --git a/common/utils/Makefile.am b/common/utils/Makefile.am
index 1773ece..d40d6cf 100644
--- a/common/utils/Makefile.am
+++ b/common/utils/Makefile.am
@@ -34,7 +34,9 @@ include $(top_srcdir)/common-rules.mk
 noinst_LTLIBRARIES = libutils.la

 libutils_la_SOURCES = \
-        utils.c \
+	cleanup.c \
+	cleanup.h \
+	utils.c \
 	utils.h
 libutils_la_CPPFLAGS = \
 	-I$(top_srcdir)/include
diff --git a/server/Makefile.am b/server/Makefile.am
index 9e13c03..8aa8d3a 100644
--- a/server/Makefile.am
+++ b/server/Makefile.am
@@ -38,7 +38,6 @@ sbin_PROGRAMS = nbdkit
 nbdkit_SOURCES = \
 	background.c \
 	captive.c \
-	cleanup.c \
 	connections.c \
 	crypto.c \
 	debug.c \
@@ -124,9 +123,11 @@ check_PROGRAMS = test-utils
 test_utils_SOURCES = \
 	test-utils.c \
 	utils.c \
-	cleanup.c \
 	extents.c
 test_utils_CPPFLAGS = \
 	-I$(top_srcdir)/include \
-	-I$(top_srcdir)/common/include
+	-I$(top_srcdir)/common/include \
+	-I$(top_srcdir)/common/utils
 test_utils_CFLAGS = $(WARNINGS_CFLAGS) $(VALGRIND_CFLAGS)
+test_utils_LDADD = \
+	$(top_builddir)/common/utils/libutils.la
-- 
2.20.1

Eric Blake

2019-Apr-23 19:06 UTC

head link

[Libguestfs] [nbdkit PATCH 2/4] filters: Utilize CLEANUP_EXTENTS_FREE

Now that cleanup.h is in common code, we can use it in our
filters. The first round focuses just on places that called
nbdkit_extents_free(), as all three callers had multiple exit paths
that definitely benefit from the macro.

Signed-off-by: Eric Blake <eblake@redhat.com>
---
 filters/offset/offset.c       | 13 +++++--------
 filters/partition/partition.c | 12 ++++--------
 filters/truncate/truncate.c   | 12 ++++--------
 filters/offset/Makefile.am    |  5 ++++-
 filters/partition/Makefile.am |  5 ++++-
 filters/truncate/Makefile.am  |  5 ++++-
 6 files changed, 25 insertions(+), 27 deletions(-)

diff --git a/filters/offset/offset.c b/filters/offset/offset.c
index ebd590b..24ccb4c 100644
--- a/filters/offset/offset.c
+++ b/filters/offset/offset.c
@@ -39,6 +39,8 @@

 #include <nbdkit-filter.h>

+#include "cleanup.h"
+
 #define THREAD_MODEL NBDKIT_THREAD_MODEL_PARALLEL

 static int64_t offset = 0, range = -1;
@@ -138,7 +140,7 @@ offset_extents (struct nbdkit_next_ops *next_ops, void
*nxdata,
                 struct nbdkit_extents *extents, int *err)
 {
   size_t i;
-  struct nbdkit_extents *extents2;
+  CLEANUP_EXTENTS_FREE struct nbdkit_extents *extents2 = NULL;
   struct nbdkit_extent e;
   int64_t real_size = next_ops->get_size (nxdata);

@@ -149,20 +151,15 @@ offset_extents (struct nbdkit_next_ops *next_ops, void
*nxdata,
   }
   if (next_ops->extents (nxdata, count, offs + offset,
                          flags, extents2, err) == -1)
-    goto error;
+    return -1;

   for (i = 0; i < nbdkit_extents_count (extents2); ++i) {
     e = nbdkit_get_extent (extents2, i);
     e.offset -= offset;
     if (nbdkit_add_extent (extents, e.offset, e.length, e.type) == -1)
-      goto error;
+      return -1;
   }
-  nbdkit_extents_free (extents2);
   return 0;
-
- error:
-  nbdkit_extents_free (extents2);
-  return -1;
 }

 static struct nbdkit_filter filter = {
diff --git a/filters/partition/partition.c b/filters/partition/partition.c
index ab692ba..a89dbec 100644
--- a/filters/partition/partition.c
+++ b/filters/partition/partition.c
@@ -41,6 +41,7 @@
 #include <nbdkit-filter.h>

 #include "byte-swapping.h"
+#include "cleanup.h"

 #include "partition.h"

@@ -229,7 +230,7 @@ partition_extents (struct nbdkit_next_ops *next_ops, void
*nxdata,
 {
   struct handle *h = handle;
   size_t i;
-  struct nbdkit_extents *extents2;
+  CLEANUP_EXTENTS_FREE struct nbdkit_extents *extents2 = NULL;
   struct nbdkit_extent e;
   int64_t real_size = next_ops->get_size (nxdata);

@@ -240,20 +241,15 @@ partition_extents (struct nbdkit_next_ops *next_ops, void
*nxdata,
   }
   if (next_ops->extents (nxdata, count, offs + h->offset,
                          flags, extents2, err) == -1)
-    goto error;
+    return -1;

   for (i = 0; i < nbdkit_extents_count (extents2); ++i) {
     e = nbdkit_get_extent (extents2, i);
     e.offset -= h->offset;
     if (nbdkit_add_extent (extents, e.offset, e.length, e.type) == -1)
-      goto error;
+      return -1;
   }
-  nbdkit_extents_free (extents2);
   return 0;
-
- error:
-  nbdkit_extents_free (extents2);
-  return -1;
 }

 static struct nbdkit_filter filter = {
diff --git a/filters/truncate/truncate.c b/filters/truncate/truncate.c
index dfc6873..076ae22 100644
--- a/filters/truncate/truncate.c
+++ b/filters/truncate/truncate.c
@@ -43,6 +43,7 @@

 #include <nbdkit-filter.h>

+#include "cleanup.h"
 #include "ispowerof2.h"
 #include "iszero.h"
 #include "rounding.h"
@@ -292,7 +293,7 @@ truncate_extents (struct nbdkit_next_ops *next_ops, void
*nxdata,
 {
   uint32_t n;
   uint64_t real_size_copy;
-  struct nbdkit_extents *extents2;
+  CLEANUP_EXTENTS_FREE struct nbdkit_extents *extents2 = NULL;
   size_t i;

   pthread_mutex_lock (&lock);
@@ -322,20 +323,15 @@ truncate_extents (struct nbdkit_next_ops *next_ops, void
*nxdata,
     n = count;
   else
     n = real_size_copy - offset;
-  if (next_ops->extents (nxdata, n, offset, flags, extents2, err) == -1) {
-    nbdkit_extents_free (extents2);
+  if (next_ops->extents (nxdata, n, offset, flags, extents2, err) == -1)
     return -1;
-  }

   for (i = 0; i < nbdkit_extents_count (extents2); ++i) {
     struct nbdkit_extent e = nbdkit_get_extent (extents2, i);

-    if (nbdkit_add_extent (extents, e.offset, e.length, e.type) == -1) {
-      nbdkit_extents_free (extents2);
+    if (nbdkit_add_extent (extents, e.offset, e.length, e.type) == -1)
       return -1;
-    }
   }
-  nbdkit_extents_free (extents2);

   return 0;
 }
diff --git a/filters/offset/Makefile.am b/filters/offset/Makefile.am
index 14591bb..525d9b6 100644
--- a/filters/offset/Makefile.am
+++ b/filters/offset/Makefile.am
@@ -40,12 +40,15 @@ nbdkit_offset_filter_la_SOURCES = \
 	$(top_srcdir)/include/nbdkit-filter.h

 nbdkit_offset_filter_la_CPPFLAGS = \
-	-I$(top_srcdir)/include
+	-I$(top_srcdir)/include \
+	-I$(top_srcdir)/common/utils
 nbdkit_offset_filter_la_CFLAGS = \
 	$(WARNINGS_CFLAGS)
 nbdkit_offset_filter_la_LDFLAGS = \
 	-module -avoid-version -shared \
 	-Wl,--version-script=$(top_srcdir)/filters/filters.syms
+nbdkit_offset_filter_la_LIBADD = \
+	$(top_builddir)/common/utils/libutils.la

 if HAVE_POD

diff --git a/filters/partition/Makefile.am b/filters/partition/Makefile.am
index 6fbbe17..f335bdc 100644
--- a/filters/partition/Makefile.am
+++ b/filters/partition/Makefile.am
@@ -45,12 +45,15 @@ nbdkit_partition_filter_la_SOURCES = \
 nbdkit_partition_filter_la_CPPFLAGS = \
 	-I$(top_srcdir)/include \
 	-I$(top_srcdir)/common/gpt \
-	-I$(top_srcdir)/common/include
+	-I$(top_srcdir)/common/include \
+	-I$(top_srcdir)/common/utils
 nbdkit_partition_filter_la_CFLAGS = \
 	$(WARNINGS_CFLAGS)
 nbdkit_partition_filter_la_LDFLAGS = \
 	-module -avoid-version -shared \
 	-Wl,--version-script=$(top_srcdir)/filters/filters.syms
+nbdkit_partition_filter_la_LIBADD = \
+	$(top_builddir)/common/utils/libutils.la

 if HAVE_POD

diff --git a/filters/truncate/Makefile.am b/filters/truncate/Makefile.am
index 86709d4..c591703 100644
--- a/filters/truncate/Makefile.am
+++ b/filters/truncate/Makefile.am
@@ -41,12 +41,15 @@ nbdkit_truncate_filter_la_SOURCES = \

 nbdkit_truncate_filter_la_CPPFLAGS = \
 	-I$(top_srcdir)/include \
-	-I$(top_srcdir)/common/include
+	-I$(top_srcdir)/common/include \
+	-I$(top_srcdir)/common/utils
 nbdkit_truncate_filter_la_CFLAGS = \
 	$(WARNINGS_CFLAGS)
 nbdkit_truncate_filter_la_LDFLAGS = \
 	-module -avoid-version -shared \
 	-Wl,--version-script=$(top_srcdir)/filters/filters.syms
+nbdkit_truncate_filter_la_LIBADD = \
+	$(top_builddir)/common/utils/libutils.la

 if HAVE_POD

-- 
2.20.1

Eric Blake

2019-Apr-23 19:06 UTC

head link

[Libguestfs] [nbdkit PATCH 3/4] filters: Utilize ACQUIRE_LOCK_FOR_CURRENT_SCOPE

Now that cleanup.h is in common code, we can use it in our filters
where it makes sense. Many uses of pthread_mutex_unlock() are not
function-wide, and over small enough snippets of code as to be easier
to read when left as-is; but when the scope is indeed function-wide or
across multiple exit paths, it is nicer to use the macro for automatic
unlock.

Signed-off-by: Eric Blake <eblake@redhat.com>
---
 filters/log/log.c             | 10 ++++------
 filters/readahead/readahead.c | 15 +++++----------
 filters/log/Makefile.am       |  5 ++++-
 filters/readahead/Makefile.am |  5 ++++-
 4 files changed, 17 insertions(+), 18 deletions(-)

diff --git a/filters/log/log.c b/filters/log/log.c
index 02a2522..513d390 100644
--- a/filters/log/log.c
+++ b/filters/log/log.c
@@ -45,6 +45,8 @@

 #include <nbdkit-filter.h>

+#include "cleanup.h"
+
 #define THREAD_MODEL NBDKIT_THREAD_MODEL_PARALLEL

 static uint64_t connections;
@@ -114,12 +116,8 @@ struct handle {
 static uint64_t
 get_id (struct handle *h)
 {
-  uint64_t r;
-
-  pthread_mutex_lock (&lock);
-  r = ++h->id;
-  pthread_mutex_unlock (&lock);
-  return r;
+  ACQUIRE_LOCK_FOR_CURRENT_SCOPE(&lock);
+  return ++h->id;
 }

 /* Output a timestamp and the log message. */
diff --git a/filters/readahead/readahead.c b/filters/readahead/readahead.c
index 5e14347..f46b6b0 100644
--- a/filters/readahead/readahead.c
+++ b/filters/readahead/readahead.c
@@ -42,6 +42,7 @@

 #include <nbdkit-filter.h>

+#include "cleanup.h"
 #include "minmax.h"

 #define THREAD_MODEL NBDKIT_THREAD_MODEL_PARALLEL
@@ -150,7 +151,7 @@ readahead_pread (struct nbdkit_next_ops *next_ops, void
*nxdata,
                  void *handle, void *buf, uint32_t count, uint64_t offset,
                  uint32_t flags, int *err)
 {
-  pthread_mutex_lock (&lock);
+  ACQUIRE_LOCK_FOR_CURRENT_SCOPE (&lock);

   while (count > 0) {
     if (length == 0) {
@@ -159,7 +160,7 @@ readahead_pread (struct nbdkit_next_ops *next_ops, void
*nxdata,
        */
       window = READAHEAD_MIN;
       if (fill_readahead (next_ops, nxdata, count, offset, flags, err) == -1)
-        goto err;
+        return -1;
     }

     /* Can we satisfy this request partly or entirely from the prefetch
@@ -179,7 +180,7 @@ readahead_pread (struct nbdkit_next_ops *next_ops, void
*nxdata,
     else if (offset == position + length) {
       window = MIN (window * 2, READAHEAD_MAX);
       if (fill_readahead (next_ops, nxdata, count, offset, flags, err) == -1)
-        goto err;
+        return -1;
     }

     /* Else it's a “miss”.  Reset everything and start again. */
@@ -187,12 +188,7 @@ readahead_pread (struct nbdkit_next_ops *next_ops, void
*nxdata,
       length = 0;
   }

-  pthread_mutex_unlock (&lock);
   return 0;
-
- err:
-  pthread_mutex_unlock (&lock);
-  return -1;
 }

 /* Any writes or write-like operations kill the prefetch buffer.
@@ -204,10 +200,9 @@ readahead_pread (struct nbdkit_next_ops *next_ops, void
*nxdata,
 static void
 kill_readahead (void)
 {
-  pthread_mutex_lock (&lock);
+  ACQUIRE_LOCK_FOR_CURRENT_SCOPE (&lock);
   window = READAHEAD_MIN;
   length = 0;
-  pthread_mutex_unlock (&lock);
 }

 static int
diff --git a/filters/log/Makefile.am b/filters/log/Makefile.am
index 271d54e..08cdd00 100644
--- a/filters/log/Makefile.am
+++ b/filters/log/Makefile.am
@@ -40,12 +40,15 @@ nbdkit_log_filter_la_SOURCES = \
 	$(top_srcdir)/include/nbdkit-filter.h

 nbdkit_log_filter_la_CPPFLAGS = \
-	-I$(top_srcdir)/include
+	-I$(top_srcdir)/include \
+	-I$(top_srcdir)/common/utils
 nbdkit_log_filter_la_CFLAGS = \
 	$(WARNINGS_CFLAGS)
 nbdkit_log_filter_la_LDFLAGS = \
 	-module -avoid-version -shared \
 	-Wl,--version-script=$(top_srcdir)/filters/filters.syms
+nbdkit_log_filter_la_LIBADD = \
+	$(top_builddir)/common/utils/libutils.la

 if HAVE_POD

diff --git a/filters/readahead/Makefile.am b/filters/readahead/Makefile.am
index 0e7a4a8..54adfb8 100644
--- a/filters/readahead/Makefile.am
+++ b/filters/readahead/Makefile.am
@@ -41,12 +41,15 @@ nbdkit_readahead_filter_la_SOURCES = \

 nbdkit_readahead_filter_la_CPPFLAGS = \
 	-I$(top_srcdir)/include \
-	-I$(top_srcdir)/common/include
+	-I$(top_srcdir)/common/include \
+	-I$(top_srcdir)/common/utils
 nbdkit_readahead_filter_la_CFLAGS = \
 	$(WARNINGS_CFLAGS)
 nbdkit_readahead_filter_la_LDFLAGS = \
 	-module -avoid-version -shared \
 	-Wl,--version-script=$(top_srcdir)/filters/filters.syms
+nbdkit_readahead_filter_la_LIBADD = \
+	$(top_builddir)/common/utils/libutils.la

 if HAVE_POD

-- 
2.20.1

Eric Blake

2019-Apr-23 19:06 UTC

head link

[Libguestfs] [nbdkit PATCH 4/4] plugins: Utilize ACQUIRE_LOCK_FOR_CURRENT_SCOPE

Now that cleanup.h is in common code, we can use it in our plugins
where it makes sense. Many uses of pthread_mutex_unlock() are not
function-wide, and over small enough snippets of code as to be easier
to read when left as-is; but when the scope is indeed function-wide or
across multiple exit paths, it is nicer to use the macro for automatic
unlock.

Signed-off-by: Eric Blake <eblake@redhat.com>
---
 plugins/data/data.c        | 26 ++++++++------------------
 plugins/file/file.c        | 18 +++++-------------
 plugins/memory/memory.c    | 26 ++++++++------------------
 plugins/nbd/nbd.c          |  4 ++--
 plugins/data/Makefile.am   |  4 +++-
 plugins/file/Makefile.am   |  5 ++++-
 plugins/memory/Makefile.am |  6 ++++--
 plugins/nbd/Makefile.am    |  4 +++-
 8 files changed, 37 insertions(+), 56 deletions(-)

diff --git a/plugins/data/data.c b/plugins/data/data.c
index 4f872ce..77cae14 100644
--- a/plugins/data/data.c
+++ b/plugins/data/data.c
@@ -46,6 +46,7 @@

 #include <nbdkit-plugin.h>

+#include "cleanup.h"
 #include "sparse.h"

 /* If raw|base64|data parameter seen. */
@@ -339,9 +340,8 @@ data_can_multi_conn (void *handle)
 static int
 data_pread (void *handle, void *buf, uint32_t count, uint64_t offset)
 {
-  pthread_mutex_lock (&lock);
+  ACQUIRE_LOCK_FOR_CURRENT_SCOPE (&lock);
   sparse_array_read (sa, buf, count, offset);
-  pthread_mutex_unlock (&lock);
   return 0;
 }

@@ -349,21 +349,16 @@ data_pread (void *handle, void *buf, uint32_t count,
uint64_t offset)
 static int
 data_pwrite (void *handle, const void *buf, uint32_t count, uint64_t offset)
 {
-  int r;
-
-  pthread_mutex_lock (&lock);
-  r = sparse_array_write (sa, buf, count, offset);
-  pthread_mutex_unlock (&lock);
-  return r;
+  ACQUIRE_LOCK_FOR_CURRENT_SCOPE (&lock);
+  return sparse_array_write (sa, buf, count, offset);
 }

 /* Zero. */
 static int
 data_zero (void *handle, uint32_t count, uint64_t offset, int may_trim)
 {
-  pthread_mutex_lock (&lock);
+  ACQUIRE_LOCK_FOR_CURRENT_SCOPE (&lock);
   sparse_array_zero (sa, count, offset);
-  pthread_mutex_unlock (&lock);
   return 0;
 }

@@ -371,9 +366,8 @@ data_zero (void *handle, uint32_t count, uint64_t offset,
int may_trim)
 static int
 data_trim (void *handle, uint32_t count, uint64_t offset)
 {
-  pthread_mutex_lock (&lock);
+  ACQUIRE_LOCK_FOR_CURRENT_SCOPE (&lock);
   sparse_array_zero (sa, count, offset);
-  pthread_mutex_unlock (&lock);
   return 0;
 }

@@ -382,12 +376,8 @@ static int
 data_extents (void *handle, uint32_t count, uint64_t offset,
               uint32_t flags, struct nbdkit_extents *extents)
 {
-  int r;
-
-  pthread_mutex_lock (&lock);
-  r = sparse_array_extents (sa, count, offset, extents);
-  pthread_mutex_unlock (&lock);
-  return r;
+  ACQUIRE_LOCK_FOR_CURRENT_SCOPE (&lock);
+  return sparse_array_extents (sa, count, offset, extents);
 }

 static struct nbdkit_plugin plugin = {
diff --git a/plugins/file/file.c b/plugins/file/file.c
index 2785399..ebfb71d 100644
--- a/plugins/file/file.c
+++ b/plugins/file/file.c
@@ -58,6 +58,7 @@

 #include <nbdkit-plugin.h>

+#include "cleanup.h"
 #include "isaligned.h"

 #ifndef O_CLOEXEC
@@ -250,12 +251,8 @@ file_get_size (void *handle)
   struct handle *h = handle;

   if (h->is_block_device) {
-    int64_t size;
-
-    pthread_mutex_lock (&lseek_lock);
-    size = block_device_size (h->fd);
-    pthread_mutex_unlock (&lseek_lock);
-    return size;
+    ACQUIRE_LOCK_FOR_CURRENT_SCOPE (&lseek_lock);
+    return block_device_size (h->fd);
   } else {
     /* Regular file. */
     struct stat statbuf;
@@ -607,13 +604,8 @@ static int
 file_extents (void *handle, uint32_t count, uint64_t offset,
               uint32_t flags, struct nbdkit_extents *extents)
 {
-  int r;
-
-  pthread_mutex_lock (&lseek_lock);
-  r = do_extents (handle, count, offset, flags, extents);
-  pthread_mutex_unlock (&lseek_lock);
-
-  return r;
+  ACQUIRE_LOCK_FOR_CURRENT_SCOPE (&lseek_lock);
+  return do_extents (handle, count, offset, flags, extents);
 }
 #endif /* SEEK_HOLE */

diff --git a/plugins/memory/memory.c b/plugins/memory/memory.c
index 0685b93..90fa99e 100644
--- a/plugins/memory/memory.c
+++ b/plugins/memory/memory.c
@@ -45,6 +45,7 @@

 #include <nbdkit-plugin.h>

+#include "cleanup.h"
 #include "sparse.h"

 /* The size of disk in bytes (initialized by size=<SIZE> parameter). */
@@ -131,9 +132,8 @@ memory_can_multi_conn (void *handle)
 static int
 memory_pread (void *handle, void *buf, uint32_t count, uint64_t offset)
 {
-  pthread_mutex_lock (&lock);
+  ACQUIRE_LOCK_FOR_CURRENT_SCOPE (&lock);
   sparse_array_read (sa, buf, count, offset);
-  pthread_mutex_unlock (&lock);
   return 0;
 }

@@ -141,21 +141,16 @@ memory_pread (void *handle, void *buf, uint32_t count,
uint64_t offset)
 static int
 memory_pwrite (void *handle, const void *buf, uint32_t count, uint64_t offset)
 {
-  int r;
-
-  pthread_mutex_lock (&lock);
-  r = sparse_array_write (sa, buf, count, offset);
-  pthread_mutex_unlock (&lock);
-  return r;
+  ACQUIRE_LOCK_FOR_CURRENT_SCOPE (&lock);
+  return sparse_array_write (sa, buf, count, offset);
 }

 /* Zero. */
 static int
 memory_zero (void *handle, uint32_t count, uint64_t offset, int may_trim)
 {
-  pthread_mutex_lock (&lock);
+  ACQUIRE_LOCK_FOR_CURRENT_SCOPE (&lock);
   sparse_array_zero (sa, count, offset);
-  pthread_mutex_unlock (&lock);
   return 0;
 }

@@ -163,9 +158,8 @@ memory_zero (void *handle, uint32_t count, uint64_t offset,
int may_trim)
 static int
 memory_trim (void *handle, uint32_t count, uint64_t offset)
 {
-  pthread_mutex_lock (&lock);
+  ACQUIRE_LOCK_FOR_CURRENT_SCOPE (&lock);
   sparse_array_zero (sa, count, offset);
-  pthread_mutex_unlock (&lock);
   return 0;
 }

@@ -174,12 +168,8 @@ static int
 memory_extents (void *handle, uint32_t count, uint64_t offset,
                 uint32_t flags, struct nbdkit_extents *extents)
 {
-  int r;
-
-  pthread_mutex_lock (&lock);
-  r = sparse_array_extents (sa, count, offset, extents);
-  pthread_mutex_unlock (&lock);
-  return r;
+  ACQUIRE_LOCK_FOR_CURRENT_SCOPE (&lock);
+  return sparse_array_extents (sa, count, offset, extents);
 }

 static struct nbdkit_plugin plugin = {
diff --git a/plugins/nbd/nbd.c b/plugins/nbd/nbd.c
index 57ffc2a..af25a67 100644
--- a/plugins/nbd/nbd.c
+++ b/plugins/nbd/nbd.c
@@ -50,6 +50,7 @@
 #include <nbdkit-plugin.h>
 #include "protocol.h"
 #include "byte-swapping.h"
+#include "cleanup.h"

 static char *sockname = NULL;
 static char *export = NULL;
@@ -266,14 +267,13 @@ nbd_request_raw (struct handle *h, uint16_t flags,
uint16_t type,
   };
   int r;

-  pthread_mutex_lock (&h->write_lock);
+  ACQUIRE_LOCK_FOR_CURRENT_SCOPE (&h->write_lock);
   nbdkit_debug ("sending request type %d (%s), flags %#x, offset %#"
PRIx64
                 ", count %#x, cookie %#" PRIx64, type,
name_of_nbd_cmd(type),
                 flags, offset, count, cookie);
   r = write_full (h->fd, &req, sizeof req);
   if (buf && !r)
     r = write_full (h->fd, buf, count);
-  pthread_mutex_unlock (&h->write_lock);
   return r;
 }

diff --git a/plugins/data/Makefile.am b/plugins/data/Makefile.am
index 022fdbc..9a36185 100644
--- a/plugins/data/Makefile.am
+++ b/plugins/data/Makefile.am
@@ -44,7 +44,8 @@ nbdkit_data_plugin_la_SOURCES = \
 nbdkit_data_plugin_la_CPPFLAGS = \
 	-I$(top_srcdir)/include \
 	-I$(top_srcdir)/common/include \
-	-I$(top_srcdir)/common/sparse
+	-I$(top_srcdir)/common/sparse \
+	-I$(top_srcdir)/common/utils
 nbdkit_data_plugin_la_CFLAGS = \
 	$(WARNINGS_CFLAGS) \
 	$(GNUTLS_CFLAGS)
@@ -53,6 +54,7 @@ nbdkit_data_plugin_la_LDFLAGS = \
 	-Wl,--version-script=$(top_srcdir)/plugins/plugins.syms
 nbdkit_data_plugin_la_LIBADD = \
 	$(top_builddir)/common/sparse/libsparse.la \
+	$(top_builddir)/common/utils/libutils.la \
 	$(GNUTLS_LIBS)

 if HAVE_POD
diff --git a/plugins/file/Makefile.am b/plugins/file/Makefile.am
index f3b3f97..1d28d26 100644
--- a/plugins/file/Makefile.am
+++ b/plugins/file/Makefile.am
@@ -41,12 +41,15 @@ nbdkit_file_plugin_la_SOURCES = \

 nbdkit_file_plugin_la_CPPFLAGS = \
 	-I$(top_srcdir)/include \
-	-I$(top_srcdir)/common/include
+	-I$(top_srcdir)/common/include \
+	-I$(top_srcdir)/common/utils
 nbdkit_file_plugin_la_CFLAGS = \
 	$(WARNINGS_CFLAGS)
 nbdkit_file_plugin_la_LDFLAGS = \
 	-module -avoid-version -shared \
 	-Wl,--version-script=$(top_srcdir)/plugins/plugins.syms
+nbdkit_file_plugin_la_LIBADD = \
+	$(top_builddir)/common/utils/libutils.la

 if HAVE_POD

diff --git a/plugins/memory/Makefile.am b/plugins/memory/Makefile.am
index 45df69d..337863e 100644
--- a/plugins/memory/Makefile.am
+++ b/plugins/memory/Makefile.am
@@ -41,14 +41,16 @@ nbdkit_memory_plugin_la_SOURCES = \

 nbdkit_memory_plugin_la_CPPFLAGS = \
 	-I$(top_srcdir)/include \
-	-I$(top_srcdir)/common/sparse
+	-I$(top_srcdir)/common/sparse \
+	-I$(top_srcdir)/common/utils
 nbdkit_memory_plugin_la_CFLAGS = \
 	$(WARNINGS_CFLAGS)
 nbdkit_memory_plugin_la_LDFLAGS = \
 	-module -avoid-version -shared \
 	-Wl,--version-script=$(top_srcdir)/plugins/plugins.syms
 nbdkit_memory_plugin_la_LIBADD = \
-	$(top_builddir)/common/sparse/libsparse.la
+	$(top_builddir)/common/sparse/libsparse.la \
+	$(top_builddir)/common/utils/libutils.la

 if HAVE_POD

diff --git a/plugins/nbd/Makefile.am b/plugins/nbd/Makefile.am
index b9d486f..7368e59 100644
--- a/plugins/nbd/Makefile.am
+++ b/plugins/nbd/Makefile.am
@@ -43,6 +43,7 @@ nbdkit_nbd_plugin_la_CPPFLAGS = \
 	-I$(top_srcdir)/include \
 	-I$(top_srcdir)/common/include \
 	-I$(top_srcdir)/common/protocol \
+	-I$(top_srcdir)/common/utils \
 	-I$(top_srcdir)/server
 nbdkit_nbd_plugin_la_CFLAGS = \
 	$(WARNINGS_CFLAGS)
@@ -50,7 +51,8 @@ nbdkit_nbd_plugin_la_LDFLAGS = \
 	-module -avoid-version -shared \
 	-Wl,--version-script=$(top_srcdir)/plugins/plugins.syms
 nbdkit_nbd_plugin_la_LIBADD = \
-	$(top_builddir)/common/protocol/libprotocol.la
+	$(top_builddir)/common/protocol/libprotocol.la \
+	$(top_builddir)/common/utils/libutils.la

 if HAVE_POD

-- 
2.20.1

Eric Blake

2019-Apr-23 19:11 UTC

head link

Re: [Libguestfs] [nbdkit PATCH 2/4] filters: Utilize CLEANUP_EXTENTS_FREE

On 4/23/19 2:06 PM, Eric Blake wrote:> Now that cleanup.h is in common code, we can use it in our
> filters. The first round focuses just on places that called
> nbdkit_extents_free(), as all three callers had multiple exit paths
> that definitely benefit from the macro.
> 
> Signed-off-by: Eric Blake <eblake@redhat.com>
> ---
>  filters/offset/offset.c       | 13 +++++--------
>  filters/partition/partition.c | 12 ++++--------
>  filters/truncate/truncate.c   | 12 ++++--------
>  filters/offset/Makefile.am    |  5 ++++-
>  filters/partition/Makefile.am |  5 ++++-
>  filters/truncate/Makefile.am  |  5 ++++-
>  6 files changed, 25 insertions(+), 27 deletions(-)
> 
> @@ -322,20 +323,15 @@ truncate_extents (struct nbdkit_next_ops *next_ops,
void *nxdata,
>      n = count;
>    else
>      n = real_size_copy - offset;
> -  if (next_ops->extents (nxdata, n, offset, flags, extents2, err) ==
-1) {
> -    nbdkit_extents_free (extents2);
> +  if (next_ops->extents (nxdata, n, offset, flags, extents2, err) ==
-1)
>      return -1;
> -  }
> 
>    for (i = 0; i < nbdkit_extents_count (extents2); ++i) {
>      struct nbdkit_extent e = nbdkit_get_extent (extents2, i);
> 
> -    if (nbdkit_add_extent (extents, e.offset, e.length, e.type) == -1) {
> -      nbdkit_extents_free (extents2);
> +    if (nbdkit_add_extent (extents, e.offset, e.length, e.type) == -1)
>        return -1;
> -    }
Of course, we have to re-add the {} if we fix nbdkit_add_extent() to set
reasonable errno so that we can '*err = errno' on failure...

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org

Richard W.M. Jones

2019-Apr-24 07:42 UTC

head link

Re: [Libguestfs] [nbdkit PATCH 1/4] cleanup: Move cleanup.c to common

On Tue, Apr 23, 2019 at 02:06:33PM -0500, Eric Blake
wrote:> The CLEANUP_FREE macro and friends can be useful to filters and
> in-tree plugins; as such, move them to common/ so more than just the
> server/ code can take advantage of our compiler magic.
> 
> Signed-off-by: Eric Blake <eblake@redhat.com>
> ---
>  common/utils/cleanup.h             | 48 ++++++++++++++++++++++++++++++
>  server/internal.h                  | 12 +-------
>  {server => common/utils}/cleanup.c |  5 ++--
>  common/utils/Makefile.am           |  4 ++-
>  server/Makefile.am                 |  7 +++--
>  5 files changed, 58 insertions(+), 18 deletions(-)
>  create mode 100644 common/utils/cleanup.h
>  rename {server => common/utils}/cleanup.c (96%)
> 
> diff --git a/common/utils/cleanup.h b/common/utils/cleanup.h
> new file mode 100644
> index 0000000..e6e6140
> --- /dev/null
> +++ b/common/utils/cleanup.h
> @@ -0,0 +1,48 @@
> +/* nbdkit
> + * Copyright (C) 2013-2019 Red Hat Inc.
> + *
> + * Redistribution and use in source and binary forms, with or without
> + * modification, are permitted provided that the following conditions are
> + * met:
> + *
> + * * Redistributions of source code must retain the above copyright
> + * notice, this list of conditions and the following disclaimer.
> + *
> + * * Redistributions in binary form must reproduce the above copyright
> + * notice, this list of conditions and the following disclaimer in the
> + * documentation and/or other materials provided with the distribution.
> + *
> + * * Neither the name of Red Hat nor the names of its contributors may be
> + * used to endorse or promote products derived from this software without
> + * specific prior written permission.
> + *
> + * THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS
IS'' AND
> + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
> + * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
> + * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR
> + * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
> + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
> + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
> + * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
> + * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
> + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
> + * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
> + * SUCH DAMAGE.
> + */
> +
> +#ifndef NBDKIT_CLEANUP_H
> +#define NBDKIT_CLEANUP_H
> +
> +#include <pthread.h>
> +
> +extern void cleanup_free (void *ptr);
> +#define CLEANUP_FREE __attribute__((cleanup (cleanup_free)))
> +extern void cleanup_extents_free (void *ptr);
> +#define CLEANUP_EXTENTS_FREE __attribute__((cleanup
(cleanup_extents_free)))
> +extern void cleanup_unlock (pthread_mutex_t **ptr);
> +#define CLEANUP_UNLOCK __attribute__((cleanup (cleanup_unlock)))
> +#define ACQUIRE_LOCK_FOR_CURRENT_SCOPE(mutex) \
> +  CLEANUP_UNLOCK pthread_mutex_t *_lock = mutex; \
> +  pthread_mutex_lock (_lock)
> +
> +#endif /* NBDKIT_CLEANUP_H */
> diff --git a/server/internal.h b/server/internal.h
> index 817f022..67fccfc 100644
> --- a/server/internal.h
> +++ b/server/internal.h
> @@ -42,6 +42,7 @@
>  #define NBDKIT_API_VERSION 2
>  #include "nbdkit-plugin.h"
>  #include "nbdkit-filter.h"
> +#include "cleanup.h"
> 
>  #ifdef __APPLE__
>  #define UNIX_PATH_MAX 104
> @@ -135,17 +136,6 @@ extern unsigned int get_socket_activation (void);
>  /* usergroup.c */
>  extern void change_user (void);
> 
> -/* cleanup.c */
> -extern void cleanup_free (void *ptr);
> -#define CLEANUP_FREE __attribute__((cleanup (cleanup_free)))
> -extern void cleanup_extents_free (void *ptr);
> -#define CLEANUP_EXTENTS_FREE __attribute__((cleanup
(cleanup_extents_free)))
> -extern void cleanup_unlock (pthread_mutex_t **ptr);
> -#define CLEANUP_UNLOCK __attribute__((cleanup (cleanup_unlock)))
> -#define ACQUIRE_LOCK_FOR_CURRENT_SCOPE(mutex) \
> -  CLEANUP_UNLOCK pthread_mutex_t *_lock = mutex; \
> -  pthread_mutex_lock (_lock)
> -
>  /* connections.c */
>  struct connection;
> 
> diff --git a/server/cleanup.c b/common/utils/cleanup.c
> similarity index 96%
> rename from server/cleanup.c
> rename to common/utils/cleanup.c
> index 292f1ce..196d910 100644
> --- a/server/cleanup.c
> +++ b/common/utils/cleanup.c
> @@ -34,10 +34,9 @@
> 
>  #include <stdio.h>
>  #include <stdlib.h>
> -#include <stdarg.h>
> -#include <string.h>
> 
> -#include "internal.h"
> +#include "cleanup.h"
> +#include "nbdkit-filter.h"
> 
>  void
>  cleanup_free (void *ptr)
> diff --git a/common/utils/Makefile.am b/common/utils/Makefile.am
> index 1773ece..d40d6cf 100644
> --- a/common/utils/Makefile.am
> +++ b/common/utils/Makefile.am
> @@ -34,7 +34,9 @@ include $(top_srcdir)/common-rules.mk
>  noinst_LTLIBRARIES = libutils.la
> 
>  libutils_la_SOURCES = \
> -        utils.c \
> +	cleanup.c \
> +	cleanup.h \
> +	utils.c \
>  	utils.h
>  libutils_la_CPPFLAGS = \
>  	-I$(top_srcdir)/include
> diff --git a/server/Makefile.am b/server/Makefile.am
> index 9e13c03..8aa8d3a 100644
> --- a/server/Makefile.am
> +++ b/server/Makefile.am
> @@ -38,7 +38,6 @@ sbin_PROGRAMS = nbdkit
>  nbdkit_SOURCES = \
>  	background.c \
>  	captive.c \
> -	cleanup.c \
>  	connections.c \
>  	crypto.c \
>  	debug.c \
> @@ -124,9 +123,11 @@ check_PROGRAMS = test-utils
>  test_utils_SOURCES = \
>  	test-utils.c \
>  	utils.c \
> -	cleanup.c \
>  	extents.c
>  test_utils_CPPFLAGS = \
>  	-I$(top_srcdir)/include \
> -	-I$(top_srcdir)/common/include
> +	-I$(top_srcdir)/common/include \
> +	-I$(top_srcdir)/common/utils
>  test_utils_CFLAGS = $(WARNINGS_CFLAGS) $(VALGRIND_CFLAGS)
> +test_utils_LDADD = \
> +	$(top_builddir)/common/utils/libutils.la
This is a simple code motion, looks fine so:

ACK

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
virt-builder quickly builds VMs from scratch
http://libguestfs.org/virt-builder.1.html

Richard W.M. Jones

2019-Apr-24 08:00 UTC

head link

Re: [Libguestfs] [nbdkit PATCH 3/4] filters: Utilize ACQUIRE_LOCK_FOR_CURRENT_SCOPE

Yes this makes the code a lot neater, so:

ACK

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
virt-df lists disk usage of guests without needing to install any
software inside the virtual machine.  Supports Linux and Windows.
http://people.redhat.com/~rjones/virt-df/

Richard W.M. Jones

2019-Apr-24 08:01 UTC

head link

Re: [Libguestfs] [nbdkit PATCH 4/4] plugins: Utilize ACQUIRE_LOCK_FOR_CURRENT_SCOPE

Again much nicer:

ACK series

I will push this in a moment.

Thanks,

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
virt-builder quickly builds VMs from scratch
http://libguestfs.org/virt-builder.1.html

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