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dm mpath: don't call dm_get_device in multipath_message

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When mutipath_message is called with an action and a device, it needs to
find the pgpath that matches that device. dm_get_device() is not the
right function for this. dm_get_device() will look for a table_device
matching the requested path in use by either the live or inactive table.
If it doesn't find the device, dm_get_device() will open it and add it
to the table. Means that multipath_message will accept any block device,
add it to the table if not present, and then look through the pgpaths
to see if it finds a match. Afterwards it will remove the device if it
was not previously in the table devices list.

This is the only function that can modify the device list of a table
besides the constructors and destructors, and it can only do this when
it was passed an invalid message.  Instead, multipath_message() should
call dm_devt_from_path() to get the device dev_t, and match that against
its pgpaths.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
This commit is contained in:
Benjamin Marzinski 2024-07-04 16:18:44 +02:00 committed by Mikulas Patocka
parent a21f9edb13
commit a48f6b82c5
1 changed files with 4 additions and 7 deletions
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11
drivers/md/dm-mpath.c
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@ -1419,8 +1419,7 @@ out:
/*
* Fail or reinstate all paths that match the provided struct dm_dev.
*/
static int action_dev(struct multipath *m, struct dm_dev *dev,
action_fn action)
static int action_dev(struct multipath *m, dev_t dev, action_fn action)
{
int r = -EINVAL;
struct pgpath *pgpath;
@ -1428,7 +1427,7 @@ static int action_dev(struct multipath *m, struct dm_dev *dev,
list_for_each_entry(pg, &m->priority_groups, list) {
list_for_each_entry(pgpath, &pg->pgpaths, list) {
if (pgpath->path.dev == dev)
if (pgpath->path.dev->bdev->bd_dev == dev)
r = action(pgpath);
}
}
@ -1959,7 +1958,7 @@ static int multipath_message(struct dm_target *ti, unsigned int argc, char **arg
char *result, unsigned int maxlen)
{
int r = -EINVAL;
struct dm_dev *dev;
dev_t dev;
struct multipath *m = ti->private;
action_fn action;
unsigned long flags;
@ -2008,7 +2007,7 @@ static int multipath_message(struct dm_target *ti, unsigned int argc, char **arg
goto out;
}
r = dm_get_device(ti, argv[1], dm_table_get_mode(ti->table), &dev);
r = dm_devt_from_path(argv[1], &dev);
if (r) {
DMWARN("message: error getting device %s",
argv[1]);
@ -2017,8 +2016,6 @@ static int multipath_message(struct dm_target *ti, unsigned int argc, char **arg
r = action_dev(m, dev, action);
dm_put_device(ti, dev);
out:
mutex_unlock(&m->work_mutex);
return r;