From a2f998a78a425edde5a1a1973c1d4854fe9d019f Mon Sep 17 00:00:00 2001 From: Hou Tao Date: Fri, 16 Dec 2022 12:23:53 +0800 Subject: dm ioctl: remove unnecessary check when using dm_get_mdptr() __hash_remove() removes hash_cell with _hash_lock locked, so acquiring _hash_lock can guarantee no-NULL hc returned from dm_get_mdptr() must have not been removed and hc->md must still be md. __hash_remove() also acquires dm_hash_cells_mutex before setting mdptr as NULL. So in dm_copy_name_and_uuid(), after acquiring dm_hash_cells_mutex and ensuring returned hc is not NULL, the returned hc must still be alive and hc->md must still be md. Remove the unnecessary hc->md != md checks when using dm_get_mdptr() with _hash_lock or dm_hash_cells_mutex acquired. Signed-off-by: Hou Tao Signed-off-by: Mike Snitzer --- drivers/md/dm-ioctl.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'drivers/md/dm-ioctl.c') diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c index 067dfc08d4c3..50a1259294d1 100644 --- a/drivers/md/dm-ioctl.c +++ b/drivers/md/dm-ioctl.c @@ -789,7 +789,7 @@ static struct dm_table *dm_get_inactive_table(struct mapped_device *md, int *src down_read(&_hash_lock); hc = dm_get_mdptr(md); - if (!hc || hc->md != md) { + if (!hc) { DMERR("device has been removed from the dev hash table."); goto out; } @@ -1500,7 +1500,7 @@ static int table_load(struct file *filp, struct dm_ioctl *param, size_t param_si /* stage inactive table */ down_write(&_hash_lock); hc = dm_get_mdptr(md); - if (!hc || hc->md != md) { + if (!hc) { DMERR("device has been removed from the dev hash table."); up_write(&_hash_lock); r = -ENXIO; @@ -2152,7 +2152,7 @@ int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid) mutex_lock(&dm_hash_cells_mutex); hc = dm_get_mdptr(md); - if (!hc || hc->md != md) { + if (!hc) { r = -ENXIO; goto out; } -- cgit v1.2.3