e8f1d2fd81
commit 37887783b3fef877bf34b8992c9199864da4afcb upstream.
This reverts commit e7be8d1dd983156b ("zram: remove double compression
logic") as it causes zram failures. It does not revert cleanly, PTR_ERR
handling was introduced in the meantime. This is handled by appropriate
IS_ERR.
When under memory pressure, zs_malloc() can fail. Before the above
commit, the allocation was retried with direct reclaim enabled (GFP_NOIO).
After the commit, it is not -- only __GFP_KSWAPD_RECLAIM is tried.
So when the failure occurs under memory pressure, the overlaying
filesystem such as ext2 (mounted by ext4 module in this case) can emit
failures, making the (file)system unusable:
EXT4-fs warning (device zram0): ext4_end_bio:343: I/O error 10 writing to inode 16386 starting block 159744)
Buffer I/O error on device zram0, logical block 159744
With direct reclaim, memory is really reclaimed and allocation succeeds,
eventually. In the worst case, the oom killer is invoked, which is proper
outcome if user sets up zram too large (in comparison to available RAM).
This very diff doesn't apply to 5.19 (stable) cleanly (see PTR_ERR note
above). Use revert of e7be8d1dd983 directly.
Link: https://bugzilla.suse.com/show_bug.cgi?id=1202203
Link: https://lkml.kernel.org/r/20220810070609.14402-1-jslaby@suse.cz
Fixes: e7be8d1dd983 ("zram: remove double compression logic")
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Alexey Romanov <avromanov@sberdevices.ru>
Cc: Dmitry Rokosov <ddrokosov@sberdevices.ru>
Cc: Lukas Czerner <lczerner@redhat.com>
Cc: <stable@vger.kernel.org> [5.19]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.