linux.git/fs/fs_struct.c, branch v6.18.21

fs: add for 'init_fs'

2026-02-26T22:58:57+00:00

[ Upstream commit 589cff4975afe1a4eaaa1d961652f50b1628d78d ]

The init_fs symbol is defined in  but was
not included in fs/fs_struct.c so fix by adding the include.

Fixes the following sparse warning:
fs/fs_struct.c:150:18: warning: symbol 'init_fs' was not declared. Should it be static?

Fixes: 3e93cd671813e ("Take fs_struct handling to new file")
Signed-off-by: Ben Dooks 
Link: https://patch.msgid.link/20260108115856.238027-1-ben.dooks@codethink.co.uk
Reviewed-by: Jan Kara 
Signed-off-by: Christian Brauner 
Signed-off-by: Sasha Levin

fold fs_struct->{lock,seq} into a seqlock

2025-07-08T08:25:19+00:00

	The combination of spinlock_t lock and seqcount_spinlock_t seq
in struct fs_struct is an open-coded seqlock_t (see linux/seqlock_types.h).
	Combine and switch to equivalent seqlock_t primitives.  AFAICS,
that does end up with the same sequence of underlying operations in all
cases.
	While we are at it, get_fs_pwd() is open-coded verbatim in
get_path_from_fd(); rather than applying conversion to it, replace with
the call of get_fs_pwd() there.  Not worth splitting the commit for that,
IMO...

	A bit of historical background - conversion of seqlock_t to
use of seqcount_spinlock_t happened several months after the same
had been done to struct fs_struct; switching fs_struct to seqlock_t
could've been done immediately after that, but it looks like nobody
had gotten around to that until now.

Signed-off-by: Al Viro 
Link: https://lore.kernel.org/20250702053437.GC1880847@ZenIV
Acked-by: Ahmed S. Darwish 
Acked-by: Peter Zijlstra (Intel) 
Reviewed-by: Christian Brauner 
Signed-off-by: Christian Brauner

kill do_each_thread()

2023-08-21T20:46:25+00:00

Eric has pointed out that we still have 3 users of do_each_thread().
Change them to use for_each_process_thread() and kill this helper.

There is a subtle change, after do_each_thread/while_each_thread g == t ==
&init_task, while after for_each_process_thread() they both point to
nowhere, but this doesn't matter.

> Why is for_each_process_thread() better than do_each_thread()?

Say, for_each_process_thread() is rcu safe, do_each_thread() is not.

And certainly

	for_each_process_thread(p, t) {
		do_something(p, t);
	}

looks better than

	do_each_thread(p, t) {
		do_something(p, t);
	} while_each_thread(p, t);

And again, there are only 3 users of this awkward helper left.  It should
have been killed years ago and in fact I thought it had already been
killed.  It uses while_each_thread() which needs some changes.

Link: https://lkml.kernel.org/r/20230817163708.GA8248@redhat.com
Signed-off-by: Oleg Nesterov 
Reviewed-by: Kees Cook 
Cc: "Christian Brauner (Microsoft)" 
Cc: Eric W. Biederman 
Cc: Jiri Slaby  # tty/serial
Signed-off-by: Andrew Morton

vfs: Use sequence counter with associated spinlock

2020-07-29T14:14:27+00:00

A sequence counter write side critical section must be protected by some
form of locking to serialize writers. A plain seqcount_t does not
contain the information of which lock must be held when entering a write
side critical section.

Use the new seqcount_spinlock_t data type, which allows to associate a
spinlock with the sequence counter. This enables lockdep to verify that
the spinlock used for writer serialization is held when the write side
critical section is entered.

If lockdep is disabled this lock association is compiled out and has
neither storage size nor runtime overhead.

Signed-off-by: Ahmed S. Darwish 
Signed-off-by: Peter Zijlstra (Intel) 
Link: https://lkml.kernel.org/r/20200720155530.1173732-19-a.darwish@linutronix.de

treewide: Add SPDX license identifier for missed files

2019-05-21T08:50:45+00:00

Add SPDX license identifiers to all files which:

 - Have no license information of any form

 - Have EXPORT_.*_SYMBOL_GPL inside which was used in the
   initial scan/conversion to ignore the file

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

  GPL-2.0-only

Signed-off-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman

sched/headers: Prepare for new header dependencies before moving code to

2017-03-02T07:42:35+00:00

We are going to split  out of , which
will have to be picked up from other headers and a couple of .c files.

Create a trivial placeholder  file that just
maps to  to make this patch obviously correct and
bisectable.

Include the new header in the files that are going to need it.

Acked-by: Linus Torvalds 
Cc: Mike Galbraith 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar

sched/headers: Prepare for new header dependencies before moving code to

2017-03-02T07:42:29+00:00

We are going to split  out of , which
will have to be picked up from other headers and a couple of .c files.

Create a trivial placeholder  file that just
maps to  to make this patch obviously correct and
bisectable.

Include the new header in the files that are going to need it.

Acked-by: Linus Torvalds 
Cc: Mike Galbraith 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar

seqcount: Add lockdep functionality to seqcount/seqlock structures

2013-11-06T11:40:26+00:00

Currently seqlocks and seqcounts don't support lockdep.

After running across a seqcount related deadlock in the timekeeping
code, I used a less-refined and more focused variant of this patch
to narrow down the cause of the issue.

This is a first-pass attempt to properly enable lockdep functionality
on seqlocks and seqcounts.

Since seqcounts are used in the vdso gettimeofday code, I've provided
non-lockdep accessors for those needs.

I've also handled one case where there were nested seqlock writers
and there may be more edge cases.

Comments and feedback would be appreciated!

Signed-off-by: John Stultz 
Signed-off-by: Peter Zijlstra 
Cc: Eric Dumazet 
Cc: Li Zefan 
Cc: Mathieu Desnoyers 
Cc: Steven Rostedt 
Cc: "David S. Miller" 
Cc: netdev@vger.kernel.org
Link: http://lkml.kernel.org/r/1381186321-4906-3-git-send-email-john.stultz@linaro.org
Signed-off-by: Ingo Molnar

constify path_get/path_put and fs_struct.c stuff

2013-03-02T04:51:07+00:00

Signed-off-by: Al Viro

kill daemonize()

2012-11-29T02:49:02+00:00

Signed-off-by: Al Viro