This is a note to let you know that I've just added the patch titled
zram: revalidate disk under init_lock
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
zram-revalidate-disk-under-init_lock.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From e7ccfc4ccb703e0f033bd4617580039898e912dd Mon Sep 17 00:00:00 2001
From: Minchan Kim <minchan@xxxxxxxxxx>
Date: Tue, 10 Jan 2017 16:58:18 -0800
Subject: zram: revalidate disk under init_lock
From: Minchan Kim <minchan@xxxxxxxxxx>
commit e7ccfc4ccb703e0f033bd4617580039898e912dd upstream.
Commit b4c5c60920e3 ("zram: avoid lockdep splat by revalidate_disk")
moved revalidate_disk call out of init_lock to avoid lockdep
false-positive splat. However, commit 08eee69fcf6b ("zram: remove
init_lock in zram_make_request") removed init_lock in IO path so there
is no worry about lockdep splat. So, let's restore it.
This patch is needed to set BDI_CAP_STABLE_WRITES atomically in next
patch.
Fixes: da9556a2367c ("zram: user per-cpu compression streams")
Link: http://lkml.kernel.org/r/1482366980-3782-3-git-send-email-minchan@xxxxxxxxxx
Signed-off-by: Minchan Kim <minchan@xxxxxxxxxx>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>
Cc: Takashi Iwai <tiwai@xxxxxxx>
Cc: Hyeoncheol Lee <cheol.lee@xxxxxxx>
Cc: <yjay.kim@xxxxxxx>
Cc: Sangseok Lee <sangseok.lee@xxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/block/zram/zram_drv.c | 8 +-------
1 file changed, 1 insertion(+), 7 deletions(-)
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -1094,14 +1094,8 @@ static ssize_t disksize_store(struct dev
zram->comp = comp;
zram->disksize = disksize;
set_capacity(zram->disk, zram->disksize >> SECTOR_SHIFT);
- up_write(&zram->init_lock);
-
- /*
- * Revalidate disk out of the init_lock to avoid lockdep splat.
- * It's okay because disk's capacity is protected by init_lock
- * so that revalidate_disk always sees up-to-date capacity.
- */
revalidate_disk(zram->disk);
+ up_write(&zram->init_lock);
return len;
Patches currently in stable-queue which might be from minchan@xxxxxxxxxx are
queue-4.9/zram-support-bdi_cap_stable_writes.patch
queue-4.9/zram-revalidate-disk-under-init_lock.patch
queue-4.9/mm-pmd-dirty-emulation-in-page-fault-handler.patch
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