linux.git/fs/proc/root.c, branch v6.12.80

procfs: make freeing proc_fs_info rcu-delayed

2024-02-25T07:10:32+00:00

makes proc_pid_ns() safe from rcu pathwalk (put_pid_ns()
is still synchronous, but that's not a problem - it does
rcu-delay everything that needs to be)

Reviewed-by: Christian Brauner 
Signed-off-by: Al Viro

fs: super: dynamically allocate the s_shrink

2023-10-04T17:32:26+00:00

In preparation for implementing lockless slab shrink, use new APIs to
dynamically allocate the s_shrink, so that it can be freed asynchronously
via RCU. Then it doesn't need to wait for RCU read-side critical section
when releasing the struct super_block.

Link: https://lkml.kernel.org/r/20230911094444.68966-39-zhengqi.arch@bytedance.com
Signed-off-by: Qi Zheng 
Reviewed-by: Muchun Song 
Acked-by: David Sterba 
Cc: Chris Mason 
Cc: Josef Bacik 
Cc: Alexander Viro 
Cc: Christian Brauner 
Cc: Abhinav Kumar 
Cc: Alasdair Kergon 
Cc: Alyssa Rosenzweig 
Cc: Andreas Dilger 
Cc: Andreas Gruenbacher 
Cc: Anna Schumaker 
Cc: Arnd Bergmann 
Cc: Bob Peterson 
Cc: Borislav Petkov 
Cc: Carlos Llamas 
Cc: Chandan Babu R 
Cc: Chao Yu 
Cc: Christian Koenig 
Cc: Chuck Lever 
Cc: Coly Li 
Cc: Dai Ngo 
Cc: Daniel Vetter 
Cc: Daniel Vetter 
Cc: "Darrick J. Wong" 
Cc: Dave Chinner 
Cc: Dave Hansen 
Cc: David Airlie 
Cc: David Hildenbrand 
Cc: Dmitry Baryshkov 
Cc: Gao Xiang 
Cc: Greg Kroah-Hartman 
Cc: Huang Rui 
Cc: Ingo Molnar 
Cc: Jaegeuk Kim 
Cc: Jani Nikula 
Cc: Jan Kara 
Cc: Jason Wang 
Cc: Jeff Layton 
Cc: Jeffle Xu 
Cc: Joel Fernandes (Google) 
Cc: Joonas Lahtinen 
Cc: Juergen Gross 
Cc: Kent Overstreet 
Cc: Kirill Tkhai 
Cc: Marijn Suijten 
Cc: "Michael S. Tsirkin" 
Cc: Mike Snitzer 
Cc: Minchan Kim 
Cc: Muchun Song 
Cc: Nadav Amit 
Cc: Neil Brown 
Cc: Oleksandr Tyshchenko 
Cc: Olga Kornievskaia 
Cc: Paul E. McKenney 
Cc: Richard Weinberger 
Cc: Rob Clark 
Cc: Rob Herring 
Cc: Rodrigo Vivi 
Cc: Roman Gushchin 
Cc: Sean Paul 
Cc: Sergey Senozhatsky 
Cc: Song Liu 
Cc: Stefano Stabellini 
Cc: Steven Price 
Cc: "Theodore Ts'o" 
Cc: Thomas Gleixner 
Cc: Tomeu Vizoso 
Cc: Tom Talpey 
Cc: Trond Myklebust 
Cc: Tvrtko Ursulin 
Cc: Vlastimil Babka 
Cc: Xuan Zhuo 
Cc: Yue Hu 
Signed-off-by: Andrew Morton

fs: pass the request_mask to generic_fillattr

2023-08-09T06:56:36+00:00

generic_fillattr just fills in the entire stat struct indiscriminately
today, copying data from the inode. There is at least one attribute
(STATX_CHANGE_COOKIE) that can have side effects when it is reported,
and we're looking at adding more with the addition of multigrain
timestamps.

Add a request_mask argument to generic_fillattr and have most callers
just pass in the value that is passed to getattr. Have other callers
(e.g. ksmbd) just pass in STATX_BASIC_STATS. Also move the setting of
STATX_CHANGE_COOKIE into generic_fillattr.

Acked-by: Joseph Qi 
Reviewed-by: Xiubo Li 
Reviewed-by: "Paulo Alcantara (SUSE)" 
Reviewed-by: Jan Kara 
Signed-off-by: Jeff Layton 
Message-Id: <20230807-mgctime-v7-2-d1dec143a704@kernel.org>
Signed-off-by: Christian Brauner

fs: port ->getattr() to pass mnt_idmap

2023-01-19T08:24:25+00:00

Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Christian Brauner (Microsoft)

proc: add some (hopefully) insightful comments

2022-07-30T01:12:35+00:00

* /proc/${pid}/net status
* removing PDE vs last close stuff (again!)
* random small stuff

Link: https://lkml.kernel.org/r/YtwrM6sDC0OQ53YB@localhost.localdomain
Signed-off-by: Alexey Dobriyan 
Signed-off-by: Andrew Morton

proc: delete unused includes

2022-07-18T00:31:39+00:00

Those aren't necessary after seq files won.

Link: https://lkml.kernel.org/r/YqnA3mS7KBt8Z4If@localhost.localdomain
Signed-off-by: Alexey Dobriyan 
Signed-off-by: Andrew Morton

fs: make helpers idmap mount aware

2021-01-24T13:27:20+00:00

Extend some inode methods with an additional user namespace argument. A
filesystem that is aware of idmapped mounts will receive the user
namespace the mount has been marked with. This can be used for
additional permission checking and also to enable filesystems to
translate between uids and gids if they need to. We have implemented all
relevant helpers in earlier patches.

As requested we simply extend the exisiting inode method instead of
introducing new ones. This is a little more code churn but it's mostly
mechanical and doesnt't leave us with additional inode methods.

Link: https://lore.kernel.org/r/20210121131959.646623-25-christian.brauner@ubuntu.com
Cc: Christoph Hellwig 
Cc: David Howells 
Cc: Al Viro 
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig 
Signed-off-by: Christian Brauner

stat: handle idmapped mounts

2021-01-24T13:27:17+00:00

The generic_fillattr() helper fills in the basic attributes associated
with an inode. Enable it to handle idmapped mounts. If the inode is
accessed through an idmapped mount map it into the mount's user
namespace before we store the uid and gid. If the initial user namespace
is passed nothing changes so non-idmapped mounts will see identical
behavior as before.

Link: https://lore.kernel.org/r/20210121131959.646623-12-christian.brauner@ubuntu.com
Cc: Christoph Hellwig 
Cc: David Howells 
Cc: Al Viro 
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig 
Reviewed-by: James Morris 
Signed-off-by: Christian Brauner

proc: s_fs_info may be NULL when proc_kill_sb is called

2020-06-10T19:54:54+00:00

syzbot found that proc_fill_super() fails before filling up sb->s_fs_info,
deactivate_locked_super() will be called and sb->s_fs_info will be NULL.
The proc_kill_sb() does not expect fs_info to be NULL which is wrong.

Link: https://lore.kernel.org/lkml/0000000000002d7ca605a7b8b1c5@google.com
Reported-by: syzbot+4abac52934a48af5ff19@syzkaller.appspotmail.com
Fixes: fa10fed30f25 ("proc: allow to mount many instances of proc in one pid namespace")
Signed-off-by: Alexey Gladkov 
Signed-off-by: Eric W. Biederman

proc: use named enums for better readability

2020-04-22T15:51:22+00:00

Signed-off-by: Alexey Gladkov 
Reviewed-by: Alexey Dobriyan 
Reviewed-by: Kees Cook 
Signed-off-by: Eric W. Biederman