diff options
| author | Christian Brauner <brauner@kernel.org> | 2024-12-13 00:03:44 +0100 |
|---|---|---|
| committer | Christian Brauner <brauner@kernel.org> | 2025-01-09 16:58:52 +0100 |
| commit | 4368898b271ad4ea3b6ae64f5cd16486a6d65430 (patch) | |
| tree | 341031d0e6be4cba439efc4dd9928095943bc4f2 /fs/nsfs.c | |
| parent | 67d676bb135cd4de9647616e73cfd059ef57c9a6 (diff) | |
fs: lockless mntns lookup for nsfs
We already made the rbtree lookup lockless for the simple lookup case.
However, walking the list of mount namespaces via nsfs still happens
with taking the read lock blocking concurrent additions of new mount
namespaces pointlessly. Plus, such additions are rare anyway so allow
lockless lookup of the previous and next mount namespace by keeping a
separate list. This also allows to make some things simpler in the code.
Link: https://lore.kernel.org/r/20241213-work-mount-rbtree-lockless-v3-5-6e3cdaf9b280@kernel.org
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Diffstat (limited to 'fs/nsfs.c')
| -rw-r--r-- | fs/nsfs.c | 5 |
1 files changed, 1 insertions, 4 deletions
diff --git a/fs/nsfs.c b/fs/nsfs.c index c675fc40ce2d..663f8656158d 100644 --- a/fs/nsfs.c +++ b/fs/nsfs.c @@ -274,10 +274,7 @@ static long ns_ioctl(struct file *filp, unsigned int ioctl, if (usize < MNT_NS_INFO_SIZE_VER0) return -EINVAL; - if (previous) - mnt_ns = lookup_prev_mnt_ns(to_mnt_ns(ns)); - else - mnt_ns = lookup_next_mnt_ns(to_mnt_ns(ns)); + mnt_ns = get_sequential_mnt_ns(to_mnt_ns(ns), previous); if (IS_ERR(mnt_ns)) return PTR_ERR(mnt_ns); |