If we set non-empty param->name or param->uuid on the DM_LIST_DEVICES_CMD
ioctl, the set values are considered filter prefixes. The ioctl will only
return entries with matching name or uuid prefix.
Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx>
---
drivers/md/dm-ioctl.c | 28 ++++++++++++++++++++++++++++
1 file changed, 28 insertions(+)
Index: linux-2.6/drivers/md/dm-ioctl.c
===================================================================
--- linux-2.6.orig/drivers/md/dm-ioctl.c 2021-03-11 18:53:58.000000000 +0100
+++ linux-2.6/drivers/md/dm-ioctl.c 2021-03-11 19:16:06.000000000 +0100
@@ -540,6 +540,30 @@ static void *get_result_buffer(struct dm
return ((void *) param) + param->data_start;
}
+static bool filter_device(struct hash_cell *hc, const char *pfx_name, const char *pfx_uuid)
+{
+ const char *val;
+ size_t val_len, pfx_len;
+
+ val = hc->name;
+ val_len = strlen(val);
+ pfx_len = strnlen(pfx_name, DM_NAME_LEN);
+ if (pfx_len > val_len)
+ return false;
+ if (memcmp(val, pfx_name, pfx_len))
+ return false;
+
+ val = hc->uuid ? hc->uuid : "";
+ val_len = strlen(val);
+ pfx_len = strnlen(pfx_uuid, DM_UUID_LEN);
+ if (pfx_len > val_len)
+ return false;
+ if (memcmp(val, pfx_uuid, pfx_len))
+ return false;
+
+ return true;
+}
+
static int list_devices(struct file *filp, struct dm_ioctl *param, size_t param_size)
{
struct rb_node *n;
@@ -557,6 +581,8 @@ static int list_devices(struct file *fil
*/
for (n = rb_first(&name_rb_tree); n; n = rb_next(n)) {
hc = container_of(n, struct hash_cell, name_node);
+ if (!filter_device(hc, param->name, param->uuid))
+ continue;
needed += align_val(offsetof(struct dm_name_list, name) + strlen(hc->name) + 1);
needed += align_val(sizeof(uint32_t) * 2);
if (param->flags & DM_UUID_FLAG && hc->uuid)
@@ -581,6 +607,8 @@ static int list_devices(struct file *fil
for (n = rb_first(&name_rb_tree); n; n = rb_next(n)) {
void *uuid_ptr;
hc = container_of(n, struct hash_cell, name_node);
+ if (!filter_device(hc, param->name, param->uuid))
+ continue;
if (old_nl)
old_nl->next = (uint32_t) ((void *) nl -
(void *) old_nl);
--
dm-devel mailing list
dm-devel@xxxxxxxxxx
https://listman.redhat.com/mailman/listinfo/dm-devel
