The status display was reading the state while the task was updating
it. Use a mutex to prevent the race.
This race was detected using ThreadSanitizer and
misc-tests/005-convert-progress-thread-crash.
==================
WARNING: ThreadSanitizer: data race
Write of size 8 by main thread:
#0 ext2_copy_inodes btrfs-progs/convert/source-ext2.c:853
#1 copy_inodes btrfs-progs/convert/main.c:145
#2 do_convert btrfs-progs/convert/main.c:1297
#3 main btrfs-progs/convert/main.c:1924
Previous read of size 8 by thread T1:
#0 print_copied_inodes btrfs-progs/convert/main.c:124
Location is stack of main thread.
Thread T1 (running) created by main thread at:
#0 pthread_create <null>
#1 task_start btrfs-progs/task-utils.c:50
#2 do_convert btrfs-progs/convert/main.c:1295
#3 main btrfs-progs/convert/main.c:1924
SUMMARY: ThreadSanitizer: data race
btrfs-progs/convert/source-ext2.c:853 in ext2_copy_inodes
Signed-off-by: Adam Buchbinder <abuchbin...@google.com>
---
convert/main.c | 12 ++++++++++--
convert/source-ext2.c | 3 +++
convert/source-fs.h | 3 +++
3 files changed, 16 insertions(+), 2 deletions(-)
diff --git a/convert/main.c b/convert/main.c
index c56382e..c9c1fd4 100644
--- a/convert/main.c
+++ b/convert/main.c
@@ -88,6 +88,7 @@
#include <fcntl.h>
#include <unistd.h>
#include <getopt.h>
+#include <pthread.h>
#include <stdbool.h>
#include "ctree.h"
@@ -119,10 +120,12 @@ static void *print_copied_inodes(void *p)
task_period_start(priv->info, 1000 /* 1s */);
while (1) {
count++;
+ pthread_mutex_lock(&priv->mutex);
printf("copy inodes [%c] [%10llu/%10llu]\r",
work_indicator[count % 4],
- (unsigned long long)priv->cur_copy_inodes,
- (unsigned long long)priv->max_copy_inodes);
+ (u64)priv->cur_copy_inodes,
+ (u64)priv->max_copy_inodes);
+ pthread_mutex_unlock(&priv->mutex);
fflush(stdout);
task_period_wait(priv->info);
}
@@ -1286,6 +1289,11 @@ static int do_convert(const char *devname, u32
convert_flags, u32 nodesize,
}
printf("creating btrfs metadata");
+ ret = pthread_mutex_init(&ctx.mutex, NULL);
+ if (ret) {
+ error("failed to init mutex: %d", ret);
+ goto fail;
+ }
ctx.max_copy_inodes = (cctx.inodes_count - cctx.free_inodes_count);
ctx.cur_copy_inodes = 0;
diff --git a/convert/source-ext2.c b/convert/source-ext2.c
index 38c3cd3..4bce4b3 100644
--- a/convert/source-ext2.c
+++ b/convert/source-ext2.c
@@ -18,6 +18,7 @@
#include "kerncompat.h"
#include <linux/limits.h>
+#include <pthread.h>
#include "disk-io.h"
#include "transaction.h"
#include "utils.h"
@@ -850,7 +851,9 @@ static int ext2_copy_inodes(struct btrfs_convert_context
*cctx,
ret = ext2_copy_single_inode(trans, root,
objectid, ext2_fs, ext2_ino,
&ext2_inode, convert_flags);
+ pthread_mutex_lock(&p->mutex);
p->cur_copy_inodes++;
+ pthread_mutex_unlock(&p->mutex);
if (ret)
return ret;
if (trans->blocks_used >= 4096) {
diff --git a/convert/source-fs.h b/convert/source-fs.h
index ca32d15..7ae6edd 100644
--- a/convert/source-fs.h
+++ b/convert/source-fs.h
@@ -17,6 +17,8 @@
#ifndef __BTRFS_CONVERT_SOURCE_FS_H__
#define __BTRFS_CONVERT_SOURCE_FS_H__
+#include <pthread.h>
+
#include "kerncompat.h"
#define CONV_IMAGE_SUBVOL_OBJECTID BTRFS_FIRST_FREE_OBJECTID
@@ -37,6 +39,7 @@ extern const struct simple_range btrfs_reserved_ranges[3];
struct task_info;
struct task_ctx {
+ pthread_mutex_t mutex;
u64 max_copy_inodes;
u64 cur_copy_inodes;
struct task_info *info;
--
2.13.2.932.g7449e964c-goog
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