+ zram-revalidate-disk-under-init_lock.patch added to -mm tree

The patch titled
     Subject: zram: revalidate disk under init_lock
has been added to the -mm tree.  Its filename is
     zram-revalidate-disk-under-init_lock.patch

This patch should soon appear at
    http://ozlabs.org/~akpm/mmots/broken-out/zram-revalidate-disk-under-init_lock.patch
and later at
    http://ozlabs.org/~akpm/mmotm/broken-out/zram-revalidate-disk-under-init_lock.patch

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------------------------------------------------------
From: Minchan Kim <minchan@kernel.org>
Subject: zram: revalidate disk under init_lock

[1] moved revalidate_disk call out of init_lock to avoid lockdep
false-positive splat. However, [2] remove init_lock in IO path
so there is no worry about lockdep splat. So, let's restore it.
This patch need to set BDI_CAP_STABLE_WRITES atomically in
next patch.

[1] b4c5c60920e3: zram: avoid lockdep splat by revalidate_disk
[2] 08eee69fcf6b: zram: remove init_lock in zram_make_request

Fixes: da9556a2367c ("zram: user per-cpu compression streams")
Link: http://lkml.kernel.org/r/1482366980-3782-3-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Sergey Senozhatsky <redacted>
Cc: Takashi Iwai <redacted>
Cc: Hyeoncheol Lee <redacted>
Cc: <redacted>
Cc: Sangseok Lee <redacted>
Cc: Hugh Dickins <hughd@google.com>
Cc: Darrick J. Wong <redacted>
Cc: <redacted> [4.7+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 drivers/block/zram/zram_drv.c |    8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff -puN drivers/block/zram/zram_drv.c~zram-revalidate-disk-under-init_lock drivers/block/zram/zram_drv.c

--- a/drivers/block/zram/zram_drv.c~zram-revalidate-disk-under-init_lock
+++ a/drivers/block/zram/zram_drv.c

@@ -1095,14 +1095,8 @@ 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 -mm which might be from minchan@kernel.org are

mm-pmd-dirty-emulation-in-page-fault-handler.patch
mm-support-anonymous-stable-page.patch
zram-revalidate-disk-under-init_lock.patch
zram-support-bdi_cap_stable_writes.patch