Kernel for Galaxy S24, rebased on CLO sources (WIP)
Go to file
Dave Wysochanski df9950d37d netfs: Only call folio_start_fscache() one time for each folio
[ Upstream commit df1c357f25d808e30b216188330e708e09e1a412 ]

If a network filesystem using netfs implements a clamp_length()
function, it can set subrequest lengths smaller than a page size.

When we loop through the folios in netfs_rreq_unlock_folios() to
set any folios to be written back, we need to make sure we only
call folio_start_fscache() once for each folio.

Otherwise, this simple testcase:

  mount -o fsc,rsize=1024,wsize=1024 127.0.0.1:/export /mnt/nfs
  dd if=/dev/zero of=/mnt/nfs/file.bin bs=4096 count=1
  1+0 records in
  1+0 records out
  4096 bytes (4.1 kB, 4.0 KiB) copied, 0.0126359 s, 324 kB/s
  echo 3 > /proc/sys/vm/drop_caches
  cat /mnt/nfs/file.bin > /dev/null

will trigger an oops similar to the following:

  page dumped because: VM_BUG_ON_FOLIO(folio_test_private_2(folio))
  ------------[ cut here ]------------
  kernel BUG at include/linux/netfs.h:44!
  ...
  CPU: 5 PID: 134 Comm: kworker/u16:5 Kdump: loaded Not tainted 6.4.0-rc5
  ...
  RIP: 0010:netfs_rreq_unlock_folios+0x68e/0x730 [netfs]
  ...
  Call Trace:
    netfs_rreq_assess+0x497/0x660 [netfs]
    netfs_subreq_terminated+0x32b/0x610 [netfs]
    nfs_netfs_read_completion+0x14e/0x1a0 [nfs]
    nfs_read_completion+0x2f9/0x330 [nfs]
    rpc_free_task+0x72/0xa0 [sunrpc]
    rpc_async_release+0x46/0x70 [sunrpc]
    process_one_work+0x3bd/0x710
    worker_thread+0x89/0x610
    kthread+0x181/0x1c0
    ret_from_fork+0x29/0x50

Fixes: 3d3c950467 ("netfs: Provide readahead and readpage netfs helpers"
Link: https://bugzilla.redhat.com/show_bug.cgi?id=2210612
Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20230608214137.856006-1-dwysocha@redhat.com/ # v1
Link: https://lore.kernel.org/r/20230915185704.1082982-1-dwysocha@redhat.com/ # v2
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-10-06 14:56:32 +02:00
arch x86/purgatory: Remove LTO flags 2023-09-23 11:11:09 +02:00
block block: factor out a bvec_set_page helper 2023-09-23 11:11:08 +02:00
certs certs: Fix build error when PKCS#11 URI contains semicolon 2023-02-09 11:28:11 +01:00
crypto crypto: lrw,xts - Replace strlcpy with strscpy 2023-09-23 11:11:01 +02:00
Documentation Revert "memcg: drop kmem.limit_in_bytes" 2023-09-23 11:11:12 +02:00
drivers media: via: Use correct dependency for camera sensor drivers 2023-10-06 14:56:32 +02:00
fs netfs: Only call folio_start_fscache() one time for each folio 2023-10-06 14:56:32 +02:00
include NFSv4.1: fix pnfs MDS=DS session trunking 2023-10-06 14:56:31 +02:00
init sched/psi: Select KERNFS as needed 2023-09-13 09:42:28 +02:00
io_uring io_uring/net: fix iter retargeting for selected buf 2023-09-23 11:11:10 +02:00
ipc ipc: fix memory leak in init_mqueue_fs() 2022-12-31 13:32:01 +01:00
kernel tracing: Have option files inc the trace array ref count 2023-09-23 11:11:11 +02:00
lib kobject: Add sanity check for kset->kobj.ktype in kset_register() 2023-09-23 11:11:07 +02:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
mm Revert "memcg: drop kmem.limit_in_bytes" 2023-09-23 11:11:12 +02:00
net NFSv4.1: fix pnfs MDS=DS session trunking 2023-10-06 14:56:31 +02:00
rust rust: allocator: Prevent mis-aligned allocation 2023-08-11 12:08:18 +02:00
samples samples/hw_breakpoint: fix building without module unloading 2023-09-23 11:11:09 +02:00
scripts kconfig: fix possible buffer overflow 2023-09-19 12:27:59 +02:00
security selinux: fix handling of empty opts in selinux_fs_context_submount() 2023-09-23 11:11:11 +02:00
sound ALSA: hda: intel-dsp-cfg: add LunarLake support 2023-09-23 11:11:04 +02:00
tools net/sched: Retire rsvp classifier 2023-09-23 11:11:13 +02:00
usr usr/gen_init_cpio.c: remove unnecessary -1 values from int file 2022-10-03 14:21:44 -07:00
virt kvm/vfio: ensure kvg instance stays around in kvm_vfio_group_add() 2023-09-13 09:42:46 +02:00
.clang-format inet: ping: use hlist_nulls rcu iterator during lookup 2022-12-01 12:42:46 +01:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore Kbuild: add Rust support 2022-09-28 09:02:20 +02:00
.mailmap 9 hotfixes. 6 for MM, 3 for other areas. Four of these patches address 2022-12-10 17:10:52 -08:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Remove Michal Marek from Kbuild maintainers 2022-11-16 14:53:00 +09:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS devlink: move code to a dedicated directory 2023-08-30 16:11:00 +02:00
Makefile Linux 6.1.55 2023-09-23 11:11:13 +02:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

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.