4.19-stable review patch. If anyone has any objections, please let me know.
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From: Khazhismel Kumykov khazhy@google.com
commit 7a636b4f03af9d541205f69e373672e7b2b60a8a upstream.
If the dm_resume method is called on a device that is not suspended, the method will suspend the device briefly, before resuming it (so that the table will be swapped).
However, there was a bug that the return value of dm_suspended_md was not checked. dm_suspended_md may return an error when it is interrupted by a signal. In this case, do_resume would call dm_swap_table, which would return -EINVAL.
This commit fixes the logic, so that error returned by dm_suspend is checked and the resume operation is undone.
Signed-off-by: Mikulas Patocka mpatocka@redhat.com Signed-off-by: Khazhismel Kumykov khazhy@google.com Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/md/dm-ioctl.c | 22 ++++++++++++++++++++-- 1 file changed, 20 insertions(+), 2 deletions(-)
--- a/drivers/md/dm-ioctl.c +++ b/drivers/md/dm-ioctl.c @@ -1039,8 +1039,26 @@ static int do_resume(struct dm_ioctl *pa suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG; if (param->flags & DM_NOFLUSH_FLAG) suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG; - if (!dm_suspended_md(md)) - dm_suspend(md, suspend_flags); + if (!dm_suspended_md(md)) { + r = dm_suspend(md, suspend_flags); + if (r) { + down_write(&_hash_lock); + hc = dm_get_mdptr(md); + if (hc && !hc->new_map) { + hc->new_map = new_map; + new_map = NULL; + } else { + r = -ENXIO; + } + up_write(&_hash_lock); + if (new_map) { + dm_sync_table(md); + dm_table_destroy(new_map); + } + dm_put(md); + return r; + } + }
old_map = dm_swap_table(md, new_map); if (IS_ERR(old_map)) {