5.15-stable patches

added patches:
	block-fix-default-io-priority-handling-again.patch

diff --git a/queue-5.15/block-fix-default-io-priority-handling-again.patch b/queue-5.15/block-fix-default-io-priority-handling-again.patch
new file mode 100644 (file)
index 0000000..5efb46c
--- /dev/null
+++ b/queue-5.15/block-fix-default-io-priority-handling-again.patch
@@ -0,0 +1,86 @@
+From e589f46445960c274cc813a1cc8e2fc73b2a1849 Mon Sep 17 00:00:00 2001
+From: Jan Kara <jack@suse.cz>
+Date: Thu, 23 Jun 2022 09:48:26 +0200
+Subject: block: fix default IO priority handling again
+
+From: Jan Kara <jack@suse.cz>
+
+commit e589f46445960c274cc813a1cc8e2fc73b2a1849 upstream.
+
+Commit e70344c05995 ("block: fix default IO priority handling")
+introduced an inconsistency in get_current_ioprio() that tasks without
+IO context return IOPRIO_DEFAULT priority while tasks with freshly
+allocated IO context will return 0 (IOPRIO_CLASS_NONE/0) IO priority.
+Tasks without IO context used to be rare before 5a9d041ba2f6 ("block:
+move io_context creation into where it's needed") but after this commit
+they became common because now only BFQ IO scheduler setups task's IO
+context. Similar inconsistency is there for get_task_ioprio() so this
+inconsistency is now exposed to userspace and userspace will see
+different IO priority for tasks operating on devices with BFQ compared
+to devices without BFQ. Furthemore the changes done by commit
+e70344c05995 change the behavior when no IO priority is set for BFQ IO
+scheduler which is also documented in ioprio_set(2) manpage:
+
+"If no I/O scheduler has been set for a thread, then by default the I/O
+priority will follow the CPU nice value (setpriority(2)).  In Linux
+kernels before version 2.6.24, once an I/O priority had been set using
+ioprio_set(), there was no way to reset the I/O scheduling behavior to
+the default. Since Linux 2.6.24, specifying ioprio as 0 can be used to
+reset to the default I/O scheduling behavior."
+
+So make sure we default to IOPRIO_CLASS_NONE as used to be the case
+before commit e70344c05995. Also cleanup alloc_io_context() to
+explicitely set this IO priority for the allocated IO context to avoid
+future surprises. Note that we tweak ioprio_best() to maintain
+ioprio_get(2) behavior and make this commit easily backportable.
+
+CC: stable@vger.kernel.org
+Fixes: e70344c05995 ("block: fix default IO priority handling")
+Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
+Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
+Signed-off-by: Jan Kara <jack@suse.cz>
+Reviewed-by: Christoph Hellwig <hch@lst.de>
+Link: https://lore.kernel.org/r/20220623074840.5960-1-jack@suse.cz
+Signed-off-by: Jens Axboe <axboe@kernel.dk>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ block/blk-ioc.c        |    1 +
+ block/ioprio.c         |    4 ++--
+ include/linux/ioprio.h |    2 +-
+ 3 files changed, 4 insertions(+), 3 deletions(-)
+
+--- a/block/blk-ioc.c
++++ b/block/blk-ioc.c
+@@ -265,6 +265,7 @@ int create_task_io_context(struct task_s
+       INIT_RADIX_TREE(&ioc->icq_tree, GFP_ATOMIC);
+       INIT_HLIST_HEAD(&ioc->icq_list);
+       INIT_WORK(&ioc->release_work, ioc_release_fn);
++      ioc->ioprio = IOPRIO_DEFAULT;
+ 
+       /*
+        * Try to install.  ioc shouldn't be installed if someone else
+--- a/block/ioprio.c
++++ b/block/ioprio.c
+@@ -189,9 +189,9 @@ out:
+ int ioprio_best(unsigned short aprio, unsigned short bprio)
+ {
+       if (!ioprio_valid(aprio))
+-              aprio = IOPRIO_DEFAULT;
++              aprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, IOPRIO_BE_NORM);
+       if (!ioprio_valid(bprio))
+-              bprio = IOPRIO_DEFAULT;
++              bprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, IOPRIO_BE_NORM);
+ 
+       return min(aprio, bprio);
+ }
+--- a/include/linux/ioprio.h
++++ b/include/linux/ioprio.h
+@@ -11,7 +11,7 @@
+ /*
+  * Default IO priority.
+  */
+-#define IOPRIO_DEFAULT        IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, IOPRIO_BE_NORM)
++#define IOPRIO_DEFAULT        IOPRIO_PRIO_VALUE(IOPRIO_CLASS_NONE, 0)
+ 
+ /*
+  * Check that a priority value has a valid class.

diff --git a/queue-5.15/series b/queue-5.15/series
index 9ff183a5001b8fcbab13c687393ecc77fe1eb09b..4f226cadbee53247ddda6d1e8edb811381627200 100644 (file)
--- a/queue-5.15/series
+++ b/queue-5.15/series
@@ -1,3 +1,4 @@
 x86-speculation-make-all-retbleed-mitigations-64-bit-only.patch
 selftests-bpf-extend-verifier-and-bpf_sock-tests-for-dst_port-loads.patch
 selftests-bpf-check-dst_port-only-on-the-client-socket.patch
+block-fix-default-io-priority-handling-again.patch