CVE-2025-71117: block: Remove queue freezing from several sysfs store callbacks

In the Linux kernel, the following vulnerability has been resolved:

block: Remove queue freezing from several sysfs store callbacks

Freezing the request queue from inside sysfs store callbacks may cause a deadlock in combination with the dm-multipath driver and the queueifnopath option. Additionally, freezing the request queue slows down system boot on systems where sysfs attributes are set synchronously.

Fix this by removing the blkmqfreezequeue() / blkmqunfreezequeue() calls from the store callbacks that do not strictly need these callbacks. Add the dataracy annotation to requestqueue.rqtimeout to suppress KCSAN data race reports about the rqtimeout reads.

This patch may cause a small delay in applying the new settings.

For all the attributes affected by this patch, I/O will complete correctly whether the old or the new value of the attribute is used.

This patch affects the following sysfs attributes: iopolldelay iotimeout nomerges readaheadkb rqaffinity

Here is an example of a deadlock triggered by running test srp/002 if this patch is not applied:

task:multipathd Call Trace: <TASK> schedule+0x8c1/0x1bf0 schedule+0xdd/0x270 schedulepreemptdisabled+0x1c/0x30 mutexlock+0xb89/0x1650 mutexlocknested+0x1f/0x30 dmtablesetrestrictions+0x823/0xdf0 bind+0x166/0x590 dmswaptable+0x2a7/0x490 doresume+0x1b1/0x610 devsuspend+0x55/0x1a0 ctlioctl+0x3a5/0x7e0 dmctlioctl+0x12/0x20 x64sysioctl+0x127/0x1a0 x64syscall+0xe2b/0x17d0 dosyscall64+0x96/0x3a0 entrySYSCALL64afterhwframe+0x4b/0x53 </TASK> task:(udev-worker) Call Trace: <TASK> schedule+0x8c1/0x1bf0 schedule+0xdd/0x270 blkmqfreezequeuewait+0xf2/0x140 blkmqfreezequeuenomemsave+0x23/0x30 queuerastore+0x14e/0x290 queueattrstore+0x23e/0x2c0 sysfskfwrite+0xde/0x140 kernfsfopwriteiter+0x3b2/0x630 vfswrite+0x4fd/0x1390 ksyswrite+0xfd/0x230 x64syswrite+0x76/0xc0 x64syscall+0x276/0x17d0 dosyscall64+0x96/0x3a0 entrySYSCALL64afterhwframe+0x4b/0x53 </TASK>