linux/fs
Enzo Matsumiya 17d912d54f smb: client: fix (remove) drop_dir_cache module parameter
Being a module parameter, it's possible to do:

  # modprobe cifs drop_dir_cache=1

Which will lead to a crash, because cifs_tcp_ses_list hasn't been
initialized yet:

  [  168.242624] BUG: kernel NULL pointer dereference, address: 0000000000000010
  [  168.242952] #PF: supervisor read access in kernel mode
  [  168.243175] #PF: error_code(0x0000) - not-present page
  [  168.243394] PGD 0 P4D 0
  [  168.243524] Oops: Oops: 0000 [#1] SMP NOPTI
  [  168.243703] CPU: 2 UID: 0 PID: 1105 Comm: modprobe Not tainted 7.0.0-lku #5 PREEMPT(lazy)
  [  168.244054] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.17.0-2-g4f253b9b-prebuilt.qemu.org 04/01/2014
  [  168.244557] RIP: 0010:cifs_param_set_drop_dir_cache+0x7c/0x100 [cifs]
  ...
  [  168.248785] Call Trace:
  [  168.248915]  <TASK>
  [  168.249023]  parse_args+0x285/0x3a0
  [  168.249204]  ? __pfx_unknown_module_param_cb+0x10/0x10
  [  168.249448]  load_module+0x192b/0x1bb0
  [  168.249637]  ? __pfx_unknown_module_param_cb+0x10/0x10
  [  168.249882]  ? kernel_read_file+0x27d/0x2b0
  [  168.250088]  init_module_from_file+0xce/0xf0
  [  168.250291]  idempotent_init_module+0xfb/0x2f0
  [  168.250496]  __x64_sys_finit_module+0x5a/0xa0
  [  168.250694]  do_syscall_64+0xe0/0x5a0
  [  168.250863]  ? exc_page_fault+0x65/0x160
  [  168.251050]  entry_SYSCALL_64_after_hwframe+0x77/0x7f
  [  168.251284] RIP: 0033:0x7fcaa12b774d

Instead of fixing this with some kind of "is module initialized"
approach, this patch instead moves that functionality to procfs,
setting a write op for the existing open_dirs entry, where
writing a 0 to it will drop the cached directory entries.

Also make it available only when CONFIG_CIFS_DEBUG=y.

A small change needed now is to not call flush_delayed_work()
on invalidate_all_cached_dirs() when called from procfs (can't sleep in
that context).
So add a @sync arg to invalidate_all_cached_dirs() to control when to
flush the delayed works.

Fixes: dde6667fa3 ("smb: client: add drop_dir_cache module parameter to invalidate cached dirents")
Signed-off-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
2026-04-22 09:54:21 -05:00
..
9p treewide: change inode->i_ino from unsigned long to u64 2026-03-06 14:31:28 +01:00
adfs vfs-7.1-rc1.misc 2026-04-13 14:20:11 -07:00
affs affs-for-7.1-tag 2026-04-13 16:39:01 -07:00
afs mm.git review status for linus..mm-stable 2026-04-15 12:59:16 -07:00
autofs vfs-7.1-rc1.misc 2026-04-13 14:20:11 -07:00
befs treewide: change inode->i_ino from unsigned long to u64 2026-03-06 14:31:28 +01:00
bfs vfs-7.1-rc1.bh.metadata 2026-04-13 12:46:42 -07:00
btrfs mm.git review status for linus..mm-stable 2026-04-15 12:59:16 -07:00
cachefiles vfs-7.1-rc1.kino 2026-04-13 12:19:01 -07:00
ceph mm.git review status for linus..mm-stable 2026-04-15 12:59:16 -07:00
coda treewide: change inode->i_ino from unsigned long to u64 2026-03-06 14:31:28 +01:00
configfs Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
cramfs treewide: change inode->i_ino from unsigned long to u64 2026-03-06 14:31:28 +01:00
crypto fscrypt updates for 7.1 2026-04-13 17:29:12 -07:00
debugfs debugfs: fix placement of EXPORT_SYMBOL_GPL for debugfs_create_str() 2026-04-02 16:15:23 +02:00
devpts Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
dlm ipv6: convert CONFIG_IPV6 to built-in only and clean up Kconfigs 2026-03-29 11:21:22 -07:00
ecryptfs treewide: change inode->i_ino from unsigned long to u64 2026-03-06 14:31:28 +01:00
efivarfs Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
efs treewide: change inode->i_ino from unsigned long to u64 2026-03-06 14:31:28 +01:00
erofs mm.git review status for linus..mm-stable 2026-04-15 12:59:16 -07:00
exfat Description for this pull request: 2026-04-13 16:57:31 -07:00
exportfs treewide: change inode->i_ino from unsigned long to u64 2026-03-06 14:31:28 +01:00
ext2 \n 2026-04-15 19:22:16 -07:00
ext4 mm.git review status for linus..mm-stable 2026-04-15 12:59:16 -07:00
f2fs mm.git review status for linus..mm-stable 2026-04-15 12:59:16 -07:00
fat vfs-7.1-rc1.bh.metadata 2026-04-13 12:46:42 -07:00
freevxfs treewide: change inode->i_ino from unsigned long to u64 2026-03-06 14:31:28 +01:00
fuse fuse update for 7.1 2026-04-15 19:04:21 -07:00
gfs2 gfs2 changes 2026-04-15 19:12:04 -07:00
hfs vfs-7.1-rc1.misc 2026-04-13 14:20:11 -07:00
hfsplus hfs/hfsplus updates for v7.1 2026-04-13 16:50:38 -07:00
hostfs Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
hpfs treewide: change inode->i_ino from unsigned long to u64 2026-03-06 14:31:28 +01:00
hugetlbfs mm.git review status for linus..mm-stable 2026-04-15 12:59:16 -07:00
iomap fscrypt updates for 7.1 2026-04-13 17:29:12 -07:00
isofs treewide: fix missed i_ino format specifier conversions 2026-03-06 14:31:30 +01:00
jbd2 vfs-7.1-rc1.kino 2026-04-13 12:19:01 -07:00
jffs2 treewide: change inode->i_ino from unsigned long to u64 2026-03-06 14:31:28 +01:00
jfs More robust data integrity checking and some fixes. 2026-04-15 19:29:18 -07:00
kernfs Driver core changes for 7.1-rc1 2026-04-13 19:03:11 -07:00
lockd treewide: change inode->i_ino from unsigned long to u64 2026-03-06 14:31:28 +01:00
minix vfs-7.1-rc1.bh.metadata 2026-04-13 12:46:42 -07:00
netfs mm.git review status for linus..mm-stable 2026-04-15 12:59:16 -07:00
nfs mm.git review status for linus..mm-stable 2026-04-15 12:59:16 -07:00
nfs_common NFSD: Remove NFSERR_EAGAIN 2026-01-02 13:43:41 -05:00
nfsd vfs-7.1-rc1.kino 2026-04-13 12:19:01 -07:00
nilfs2 mm.git review status for linus..mm-stable 2026-04-15 12:59:16 -07:00
nls fs/nls: Fix inconsistency between utf8_to_utf32() and utf32_to_utf8() 2025-12-01 11:58:06 +02:00
notify \n 2026-04-15 19:18:51 -07:00
ntfs3 mm.git review status for linus..mm-stable 2026-04-15 12:59:16 -07:00
ocfs2 mm.git review status for linus..mm-stable 2026-04-15 12:59:16 -07:00
omfs vfs-7.1-rc1.misc 2026-04-13 14:20:11 -07:00
openpromfs
orangefs treewide: change inode->i_ino from unsigned long to u64 2026-03-06 14:31:28 +01:00
overlayfs lsm/stable-7.1 PR 20260410 2026-04-13 15:17:28 -07:00
proc mm.git review status for linus..mm-stable 2026-04-15 12:59:16 -07:00
pstore mm.git review status for linus..mm-stable 2026-04-15 12:59:16 -07:00
qnx4 vfs-7.1-rc1.bh.metadata 2026-04-13 12:46:42 -07:00
qnx6 vfs-7.1-rc1.bh.metadata 2026-04-13 12:46:42 -07:00
quota quota: Fix race of dquot_scan_active() with quota deactivation 2026-03-25 13:15:36 +01:00
ramfs folio_batch: rename pagevec.h to folio_batch.h 2026-04-05 13:53:07 -07:00
resctrl mm.git review status for linus..mm-stable 2026-04-15 12:59:16 -07:00
romfs mm.git review status for linus..mm-stable 2026-02-18 20:50:32 -08:00
smb smb: client: fix (remove) drop_dir_cache module parameter 2026-04-22 09:54:21 -05:00
squashfs Squashfs: check metadata block offset is within range 2026-02-24 11:13:27 -08:00
sysfs Driver core changes for 7.1-rc1 2026-04-13 19:03:11 -07:00
tests fs/tests: exec: Remove bad test vector 2026-03-18 11:41:53 -07:00
tracefs tracefs updates for 7.1: 2026-04-15 16:27:32 -07:00
ubifs treewide: change inode->i_ino from unsigned long to u64 2026-03-06 14:31:28 +01:00
udf \n 2026-04-15 19:22:16 -07:00
ufs vfs-7.1-rc1.bh.metadata 2026-04-13 12:46:42 -07:00
unicode Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
vboxsf Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
verity vfs-7.1-rc1.kino 2026-04-13 12:19:01 -07:00
xfs xfs: new code for Linux 7.1 2026-04-13 17:03:48 -07:00
zonefs mm.git review status for linus..mm-stable 2026-04-15 12:59:16 -07:00
aio.c aio: Stop using i_private_data and i_private_lock 2026-03-26 15:03:30 +01:00
anon_inodes.c anon_inodes: convert to FD_ADD() 2025-11-28 12:42:31 +01:00
attr.c fs: attr: fix comment formatting and spelling issues 2026-04-07 11:26:11 +02:00
backing-file.c lsm: add backing_file LSM hooks 2026-04-03 16:53:50 -04:00
bad_inode.c fs: refactor ->update_time handling 2026-01-12 14:01:32 +01:00
binfmt_elf_fdpic.c vfs-7.1-rc1.kino 2026-04-13 12:19:01 -07:00
binfmt_elf.c mm: unexport vm_brk_flags() and eliminate vm_flags parameter 2026-04-05 13:53:39 -07:00
binfmt_flat.c
binfmt_misc.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
binfmt_script.c
bpf_fs_kfuncs.c bpf: Remove redundant KF_TRUSTED_ARGS flag from all kfuncs 2026-01-02 12:04:28 -08:00
buffer.c mm.git review status for linus..mm-stable 2026-04-15 12:59:16 -07:00
char_dev.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
compat_binfmt_elf.c
coredump.c vfs-7.1-rc1.misc 2026-04-13 14:20:11 -07:00
d_path.c dcache: permit dynamic_dname()s up to NAME_MAX 2026-04-07 12:32:22 +02:00
dax.c fs: remove unncessary pagevec.h includes 2026-04-05 13:53:06 -07:00
dcache.c vfs: get rid of BUG_ON() in d_mark_tmpfile_name() 2026-04-14 12:01:12 -05:00
direct-io.c
drop_caches.c
eventfd.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
eventpoll.c vfs-7.1-rc1.kino 2026-04-13 12:19:01 -07:00
exec.c exec: use strnlen() in __set_task_comm 2026-04-01 12:26:07 -07:00
fcntl.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
fhandle.c Convert more 'alloc_obj' cases to default GFP_KERNEL arguments 2026-02-21 20:03:00 -08:00
file_attr.c vfs-7.0-rc2.fixes 2026-02-25 10:34:23 -08:00
file_table.c lsm/stable-7.1 PR 20260410 2026-04-13 15:17:28 -07:00
file.c vfs-7.1-rc1.misc 2026-04-13 14:20:11 -07:00
filesystems.c sysfs(2): fs_index() argument is _not_ a pathname 2026-01-16 12:52:04 -05:00
fs_context.c vfs-7.1-rc1.misc 2026-04-13 14:20:11 -07:00
fs_dirent.c fs: rename fs_types.h to fs_dirent.h 2025-11-05 09:51:30 +01:00
fs_parser.c fs: remove fsparam_path / fs_param_is_path 2026-02-19 14:34:26 +01:00
fs_pin.c
fs_struct.c fs: add <linux/init_task.h> for 'init_fs' 2026-01-14 16:50:37 +01:00
fs-writeback.c writeback: don't block sync for filesystems with no data integrity guarantees 2026-03-20 14:18:56 +01:00
fserror.c treewide: change inode->i_ino from unsigned long to u64 2026-03-06 14:31:28 +01:00
fsopen.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
init.c struct filename series 2026-02-09 16:58:28 -08:00
inode.c vfs-7.1-rc1.bh.metadata 2026-04-13 12:46:42 -07:00
internal.h lsm/stable-7.1 PR 20260410 2026-04-13 15:17:28 -07:00
ioctl.c
Kconfig
Kconfig.binfmt
kernel_read_file.c
libfs.c vfs-7.1-rc1.bh.metadata 2026-04-13 12:46:42 -07:00
locks.c treewide: change inode->i_ino from unsigned long to u64 2026-03-06 14:31:28 +01:00
Makefile vfs-7.0-rc1.nullfs 2026-02-09 13:41:34 -08:00
mbcache.c vfs-7.1-rc1.misc 2026-04-13 14:20:11 -07:00
mnt_idmapping.c treewide: Replace kmalloc with kmalloc_obj for non-scalar types 2026-02-21 01:02:28 -08:00
mount.h fs: add immutable rootfs 2026-01-12 16:52:09 +01:00
mpage.c mm.git review status for linus..mm-stable 2026-04-15 12:59:16 -07:00
namei.c vfs-7.1-rc1.misc 2026-04-13 14:20:11 -07:00
namespace.c mount: always duplicate mount 2026-04-14 09:30:15 +02:00
nsfs.c vfs-7.1-rc1.kino 2026-04-13 12:19:01 -07:00
nullfs.c fs: add immutable rootfs 2026-01-12 16:52:09 +01:00
open.c fs: remove do_sys_truncate 2026-03-23 12:41:58 +01:00
pidfs.c vfs-7.1-rc1.pidfs 2026-04-13 13:27:11 -07:00
pipe.c treewide: change inode->i_ino from unsigned long to u64 2026-03-06 14:31:28 +01:00
pnode.c
pnode.h
posix_acl.c treewide: Replace kmalloc with kmalloc_obj for non-scalar types 2026-02-21 01:02:28 -08:00
proc_namespace.c
read_write.c fs: add setlease to generic_ro_fops and read-only filesystem directory operations 2026-01-12 10:55:45 +01:00
readdir.c fs: Replace user_access_{begin/end} by scoped user access 2026-03-24 14:44:02 +01:00
remap_range.c
select.c vfs-7.1-rc1.misc 2026-04-13 14:20:11 -07:00
seq_file.c treewide: Replace kmalloc with kmalloc_obj for non-scalar types 2026-02-21 01:02:28 -08:00
signalfd.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
splice.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
stack.c
stat.c statx: switch to CLASS(filename_maybe_null) 2026-01-16 12:52:04 -05:00
statfs.c user_statfs(): switch to CLASS(filename) 2026-01-16 12:52:04 -05:00
super.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
sync.c treewide: Replace kmalloc with kmalloc_obj for non-scalar types 2026-02-21 01:02:28 -08:00
sysctls.c
timerfd.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
userfaultfd.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
utimes.c do_utimes_path(): switch to CLASS(filename_uflags) 2026-01-16 12:52:03 -05:00
xattr.c xattr: support extended attributes on sockets 2026-03-02 11:06:42 +01:00