You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
mdadm/SOURCES/0160-Fix-race-of-mdadm-add-...

142 lines
4.5 KiB

This file contains ambiguous Unicode characters!

This file contains ambiguous Unicode characters that may be confused with others in your current locale. If your use case is intentional and legitimate, you can safely ignore this warning. Use the Escape button to highlight these characters.

From ed2c2cb3d440f3bd2692f1896446c4bcc703f05c Mon Sep 17 00:00:00 2001
From: Li Xiao Keng <lixiaokeng@huawei.com>
Date: Thu, 7 Sep 2023 19:37:44 +0800
Subject: [PATCH 160/165] Fix race of "mdadm --add" and "mdadm --incremental"
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
There is a raid1 with sda and sdb. And we add sdc to this raid,
it may return -EBUSY.
The main process of --add:
1. dev_opensdc) in Manage_add
2. store_super1(st, di->fd) in write_init_super1
3. fsync(fd) in store_super1
4. close(di->fd) in write_init_super1
5. ioctl(ADD_NEW_DISK)
Step 2 and 3 will add sdc to metadata of raid1. There will be
udev(change of sdc) event after step4. Then "/usr/sbin/mdadm
--incremental --export $devnode --offroot $env{DEVLINKS}"
will be run, and the sdc will be added to the raid1. Then
step 5 will return -EBUSY because it checks if device isn't
claimed in md_import_device()->lock_rdev()->blkdev_get_by_dev()
->blkdev_get().
It will be confusing for users because sdc is added first time.
The "incremental" will get map_lock before add sdc to raid1.
So we add map_lock before write_init_super in "mdadm --add"
to fix the race of "add" and "incremental".
Signed-off-by: Li Xiao Keng <lixiaokeng@huawei.com>
Signed-off-by: Guanqin Miao <miaoguanqin@huawei.com>
Reviewed-by: Mariusz Tkaczyk <mariusz.tkaczyk@linux.intel.com>
Signed-off-by: Jes Sorensen <jes@trained-monkey.org>
---
Manage.c | 24 ++++++++++++++++--------
1 file changed, 16 insertions(+), 8 deletions(-)
diff --git a/Manage.c b/Manage.c
index f997b163..075dd720 100644
--- a/Manage.c
+++ b/Manage.c
@@ -704,6 +704,7 @@ int Manage_add(int fd, int tfd, struct mddev_dev *dv,
struct supertype *dev_st;
int j;
mdu_disk_info_t disc;
+ struct map_ent *map = NULL;
if (!get_dev_size(tfd, dv->devname, &ldsize)) {
if (dv->disposition == 'M')
@@ -907,6 +908,9 @@ int Manage_add(int fd, int tfd, struct mddev_dev *dv,
disc.raid_disk = 0;
}
+ if (map_lock(&map))
+ pr_err("failed to get exclusive lock on mapfile when add disk\n");
+
if (array->not_persistent==0) {
int dfd;
if (dv->disposition == 'j')
@@ -918,9 +922,9 @@ int Manage_add(int fd, int tfd, struct mddev_dev *dv,
dfd = dev_open(dv->devname, O_RDWR | O_EXCL|O_DIRECT);
if (tst->ss->add_to_super(tst, &disc, dfd,
dv->devname, INVALID_SECTORS))
- return -1;
+ goto unlock;
if (tst->ss->write_init_super(tst))
- return -1;
+ goto unlock;
} else if (dv->disposition == 'A') {
/* this had better be raid1.
* As we are "--re-add"ing we must find a spare slot
@@ -978,14 +982,14 @@ int Manage_add(int fd, int tfd, struct mddev_dev *dv,
pr_err("add failed for %s: could not get exclusive access to container\n",
dv->devname);
tst->ss->free_super(tst);
- return -1;
+ goto unlock;
}
/* Check if metadata handler is able to accept the drive */
if (!tst->ss->validate_geometry(tst, LEVEL_CONTAINER, 0, 1, NULL,
0, 0, dv->devname, NULL, 0, 1)) {
close(container_fd);
- return -1;
+ goto unlock;
}
Kill(dv->devname, NULL, 0, -1, 0);
@@ -994,7 +998,7 @@ int Manage_add(int fd, int tfd, struct mddev_dev *dv,
dv->devname, INVALID_SECTORS)) {
close(dfd);
close(container_fd);
- return -1;
+ goto unlock;
}
if (!mdmon_running(tst->container_devnm))
tst->ss->sync_metadata(tst);
@@ -1005,7 +1009,7 @@ int Manage_add(int fd, int tfd, struct mddev_dev *dv,
dv->devname);
close(container_fd);
tst->ss->free_super(tst);
- return -1;
+ goto unlock;
}
sra->array.level = LEVEL_CONTAINER;
/* Need to set data_offset and component_size */
@@ -1020,7 +1024,7 @@ int Manage_add(int fd, int tfd, struct mddev_dev *dv,
pr_err("add new device to external metadata failed for %s\n", dv->devname);
close(container_fd);
sysfs_free(sra);
- return -1;
+ goto unlock;
}
ping_monitor(devnm);
sysfs_free(sra);
@@ -1034,7 +1038,7 @@ int Manage_add(int fd, int tfd, struct mddev_dev *dv,
else
pr_err("add new device failed for %s as %d: %s\n",
dv->devname, j, strerror(errno));
- return -1;
+ goto unlock;
}
if (dv->disposition == 'j') {
pr_err("Journal added successfully, making %s read-write\n", devname);
@@ -1045,7 +1049,11 @@ int Manage_add(int fd, int tfd, struct mddev_dev *dv,
}
if (verbose >= 0)
pr_err("added %s\n", dv->devname);
+ map_unlock(&map);
return 1;
+unlock:
+ map_unlock(&map);
+ return -1;
}
int Manage_remove(struct supertype *tst, int fd, struct mddev_dev *dv,
--
2.40.1