--- /dev/null
+From ffec85d53d0f39ee4680a2cf0795255e000e1feb Mon Sep 17 00:00:00 2001
+From: Eric Biggers <ebiggers@google.com>
+Date: Thu, 2 Feb 2023 16:55:03 -0800
+Subject: ext4: fix cgroup writeback accounting with fs-layer encryption
+
+From: Eric Biggers <ebiggers@google.com>
+
+commit ffec85d53d0f39ee4680a2cf0795255e000e1feb upstream.
+
+When writing a page from an encrypted file that is using
+filesystem-layer encryption (not inline encryption), ext4 encrypts the
+pagecache page into a bounce page, then writes the bounce page.
+
+It also passes the bounce page to wbc_account_cgroup_owner(). That's
+incorrect, because the bounce page is a newly allocated temporary page
+that doesn't have the memory cgroup of the original pagecache page.
+This makes wbc_account_cgroup_owner() not account the I/O to the owner
+of the pagecache page as it should.
+
+Fix this by always passing the pagecache page to
+wbc_account_cgroup_owner().
+
+Fixes: 001e4a8775f6 ("ext4: implement cgroup writeback support")
+Cc: stable@vger.kernel.org
+Reported-by: Matthew Wilcox (Oracle) <willy@infradead.org>
+Signed-off-by: Eric Biggers <ebiggers@google.com>
+Acked-by: Tejun Heo <tj@kernel.org>
+Link: https://lore.kernel.org/r/20230203005503.141557-1-ebiggers@kernel.org
+Signed-off-by: Theodore Ts'o <tytso@mit.edu>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ fs/ext4/page-io.c | 11 ++++++-----
+ 1 file changed, 6 insertions(+), 5 deletions(-)
+
+--- a/fs/ext4/page-io.c
++++ b/fs/ext4/page-io.c
+@@ -388,7 +388,8 @@ static int io_submit_init_bio(struct ext
+
+ static int io_submit_add_bh(struct ext4_io_submit *io,
+ struct inode *inode,
+- struct page *page,
++ struct page *pagecache_page,
++ struct page *bounce_page,
+ struct buffer_head *bh)
+ {
+ int ret;
+@@ -403,10 +404,11 @@ submit_and_retry:
+ return ret;
+ io->io_bio->bi_write_hint = inode->i_write_hint;
+ }
+- ret = bio_add_page(io->io_bio, page, bh->b_size, bh_offset(bh));
++ ret = bio_add_page(io->io_bio, bounce_page ?: pagecache_page,
++ bh->b_size, bh_offset(bh));
+ if (ret != bh->b_size)
+ goto submit_and_retry;
+- wbc_account_io(io->io_wbc, page, bh->b_size);
++ wbc_account_io(io->io_wbc, pagecache_page, bh->b_size);
+ io->io_next_block++;
+ return 0;
+ }
+@@ -514,8 +516,7 @@ int ext4_bio_write_page(struct ext4_io_s
+ do {
+ if (!buffer_async_write(bh))
+ continue;
+- ret = io_submit_add_bh(io, inode,
+- data_page ? data_page : page, bh);
++ ret = io_submit_add_bh(io, inode, page, data_page, bh);
+ if (ret) {
+ /*
+ * We only get here on ENOMEM. Not much else
--- /dev/null
+From ebiggers@kernel.org Fri Mar 17 13:57:17 2023
+From: Eric Biggers <ebiggers@kernel.org>
+Date: Thu, 16 Mar 2023 23:27:43 -0700
+Subject: fs: sysfs_emit_at: Remove PAGE_SIZE alignment check
+To: stable@vger.kernel.org
+Cc: Joe Perches <joe@perches.com>, Lucas Wei <lucaswei@google.com>, linux-mm@kvack.org, kernel test robot <yujie.liu@intel.com>
+Message-ID: <20230317062743.313169-1-ebiggers@kernel.org>
+
+From: Eric Biggers <ebiggers@kernel.org>
+
+From: Eric Biggers <ebiggers@google.com>
+
+[No upstream commit because this fixes a bug in a backport.]
+
+Before upstream commit 59bb47985c1d ("mm, sl[aou]b: guarantee natural
+alignment for kmalloc(power-of-two)") which went into v5.4, kmalloc did
+*not* always guarantee that PAGE_SIZE allocations are PAGE_SIZE-aligned.
+
+Upstream commit 2efc459d06f1 ("sysfs: Add sysfs_emit and sysfs_emit_at
+to format sysfs output") added two WARN()s that trigger when PAGE_SIZE
+allocations are not PAGE_SIZE-aligned. This was backported to old
+kernels that don't guarantee PAGE_SIZE alignment.
+
+Commit 10ddfb495232 ("fs: sysfs_emit: Remove PAGE_SIZE alignment check")
+in 4.19.y, and its equivalent in 4.14.y and 4.9.y, tried to fix this
+bug. However, only it handled sysfs_emit(), not sysfs_emit_at().
+
+Fix it in sysfs_emit_at() too.
+
+A reproducer is to build the kernel with the following options:
+
+ CONFIG_SLUB=y
+ CONFIG_SLUB_DEBUG=y
+ CONFIG_SLUB_DEBUG_ON=y
+ CONFIG_PM=y
+ CONFIG_SUSPEND=y
+ CONFIG_PM_WAKELOCKS=y
+
+Then run:
+
+ echo foo > /sys/power/wake_lock && cat /sys/power/wake_lock
+
+Fixes: cb1f69d53ac8 ("sysfs: Add sysfs_emit and sysfs_emit_at to format sysfs output")
+Reported-by: kernel test robot <yujie.liu@intel.com>
+Link: https://lore.kernel.org/r/202303141634.1e64fd76-yujie.liu@intel.com
+Signed-off-by: Eric Biggers <ebiggers@google.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ fs/sysfs/file.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/fs/sysfs/file.c
++++ b/fs/sysfs/file.c
+@@ -592,7 +592,7 @@ int sysfs_emit_at(char *buf, int at, con
+ va_list args;
+ int len;
+
+- if (WARN(!buf || offset_in_page(buf) || at < 0 || at >= PAGE_SIZE,
++ if (WARN(!buf || at < 0 || at >= PAGE_SIZE,
+ "invalid sysfs_emit_at: buf:%p at:%d\n", buf, at))
+ return 0;
+
projects / thirdparty / kernel / stable-queue.git / commitdiff
