The commit is pushed to "branch-rh9-5.14.vz9.1.x-ovz" and will appear at
https://src.openvz.org/scm/ovz/vzkernel.git
after ark-5.14
------>
commit 7e108c9027dd32bbc09d63d054f36491ef2932a6
Author: Kirill Tkhai <ktk...@virtuozzo.com>
Date: Tue Sep 28 19:17:30 2021 +0300
push_backup: Do not take write lock on ENOTTY
Userspace may pass wrong command. Do not take write lock then.
To_merge: 69eac404315a ("dm: Add push backup driver")
Signed-off-by: Kirill Tkhai <ktk...@virtuozzo.com>
---
drivers/md/dm-push-backup.c | 23 +++++++++++------------
1 file changed, 11 insertions(+), 12 deletions(-)
diff --git a/drivers/md/dm-push-backup.c b/drivers/md/dm-push-backup.c
index 6d7b1859298a..1500d0681cee 100644
--- a/drivers/md/dm-push-backup.c
+++ b/drivers/md/dm-push-backup.c
@@ -329,11 +329,10 @@ static void pb_release_clone(struct request *clone,
blk_put_request(clone);
}
-static bool msg_wants_down_read(const char *cmd)
+static bool msg_wants_down_write(const char *cmd)
{
- if (!strcmp(cmd, "push_backup_read") ||
- !strcmp(cmd, "push_backup_write") ||
- !strcmp(cmd, "push_backup_statistics"))
+ if (!strcmp(cmd, "push_backup_start") ||
+ !strcmp(cmd, "push_backup_stop"))
return true;
return false;
@@ -567,7 +566,7 @@ static int pb_message(struct dm_target *ti, unsigned int
argc, char **argv,
struct push_backup *pb = ti->private;
int ret = -EPERM;
u64 val, val2;
- bool read;
+ bool write;
if (!capable(CAP_SYS_ADMIN))
goto out;
@@ -576,11 +575,11 @@ static int pb_message(struct dm_target *ti, unsigned int
argc, char **argv,
if (argc < 1)
goto out;
- read = msg_wants_down_read(argv[0]);
- if (read)
- ret = down_read_killable(&pb->ctl_rwsem);
- else
+ write = msg_wants_down_write(argv[0]);
+ if (write)
ret = down_write_killable(&pb->ctl_rwsem);
+ else
+ ret = down_read_killable(&pb->ctl_rwsem);
if (unlikely(ret))
goto out;
@@ -612,10 +611,10 @@ static int pb_message(struct dm_target *ti, unsigned int
argc, char **argv,
}
unlock:
- if (read)
- up_read(&pb->ctl_rwsem);
- else
+ if (write)
up_write(&pb->ctl_rwsem);
+ else
+ up_read(&pb->ctl_rwsem);
out:
return ret;
}
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