Bug:
# btrfs-image -t0 -c9 /dev/sda6 /tmp/btrfs_image.img
(hang)
# btrfs-image -r -t0 /tmp/btrfs_image.img /dev/sda6
(hang)
Reason:
Program need to create at least 1 thread for compress/decompress.
but if user specify -t0 in argument, it overwrite the default value
of 1, then the program really created 0 thread, and caused above
error.
Fix:
We can add a check, to make program not allow -t0 argument,
but there are still exist another problem.
for ex, in node with 4 cpus:
btrfs-image -c9 -t1: 4 threads (1 means use nr_cpus)
-c9 -t2: 2 threads
-c9 -t3: 3 threads
...
(-t1 have more threads than -t2 and -t3)
So we change to use value of 0 as "use nr_cpus threads", then:
btrfs-image [no -t arg]: use nr_cpus threads
-t0: use nr_cpus threads
-t val: use val threads.
Signed-off-by: Zhao Lei <zhaolei@xxxxxxxxxxxxxx>
---
btrfs-image.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/btrfs-image.c b/btrfs-image.c
index f48d81a..7f49cce 100644
--- a/btrfs-image.c
+++ b/btrfs-image.c
@@ -2690,7 +2690,7 @@ int main(int argc, char *argv[])
{
char *source;
char *target;
- u64 num_threads = 1;
+ u64 num_threads = 0;
u64 compress_level = 0;
int create = 1;
int old_restore = 0;
@@ -2786,7 +2786,8 @@ int main(int argc, char *argv[])
}
}
- if (num_threads == 1 && compress_level > 0) {
+ if ((compress_level > 0 || create == 0) &&
+ num_threads == 0) {
num_threads = sysconf(_SC_NPROCESSORS_ONLN);
if (num_threads <= 0)
num_threads = 1;
--
1.8.5.1
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