github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-05-24 23:22:31 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

kernfs: switch global kernfs_idr_lock to per-fs lock

Browse Source 
The kernfs implementation has big lock granularity(kernfs_idr_lock) so
every kernfs-based(e.g., sysfs, cgroup) fs are able to compete the lock.

This patch switches the global kernfs_idr_lock to per-fs lock, which
put the spinlock into kernfs_root.

Signed-off-by: Jinliang Zheng <alexjlzheng@tencent.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20250415153659.14950-2-alexjlzheng@tencent.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Jinliang Zheng 2025-04-15 23:36:58 +08:00 committed by Greg Kroah-Hartman
parent 2806c6b8f3
commit cec59c440a
2 changed files with 8 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
fs/kernfs/dir.c
View File

@ -27,7 +27,6 @@ DEFINE_RWLOCK(kernfs_rename_lock); /* kn->parent and ->name */
*/
static DEFINE_SPINLOCK(kernfs_pr_cont_lock);
static char kernfs_pr_cont_buf[PATH_MAX]; /* protected by pr_cont_lock */
static DEFINE_SPINLOCK(kernfs_idr_lock); /* root->ino_idr */
#define rb_to_kn(X) rb_entry((X), struct kernfs_node, rb)
@ -584,9 +583,9 @@ void kernfs_put(struct kernfs_node *kn)
if (kernfs_type(kn) == KERNFS_LINK)
kernfs_put(kn->symlink.target_kn);
spin_lock(&kernfs_idr_lock);
spin_lock(&root->kernfs_idr_lock);
idr_remove(&root->ino_idr, (u32)kernfs_ino(kn));
spin_unlock(&kernfs_idr_lock);
spin_unlock(&root->kernfs_idr_lock);
call_rcu(&kn->rcu, kernfs_free_rcu);
@ -639,13 +638,13 @@ static struct kernfs_node *__kernfs_new_node(struct kernfs_root *root,
goto err_out1;
idr_preload(GFP_KERNEL);
spin_lock(&kernfs_idr_lock);
spin_lock(&root->kernfs_idr_lock);
ret = idr_alloc_cyclic(&root->ino_idr, kn, 1, 0, GFP_ATOMIC);
if (ret >= 0 && ret < root->last_id_lowbits)
root->id_highbits++;
id_highbits = root->id_highbits;
root->last_id_lowbits = ret;
spin_unlock(&kernfs_idr_lock);
spin_unlock(&root->kernfs_idr_lock);
idr_preload_end();
if (ret < 0)
goto err_out2;
@ -681,9 +680,9 @@ static struct kernfs_node *__kernfs_new_node(struct kernfs_root *root,
return kn;
err_out3:
spin_lock(&kernfs_idr_lock);
spin_lock(&root->kernfs_idr_lock);
idr_remove(&root->ino_idr, (u32)kernfs_ino(kn));
spin_unlock(&kernfs_idr_lock);
spin_unlock(&root->kernfs_idr_lock);
err_out2:
kmem_cache_free(kernfs_node_cache, kn);
err_out1:
@ -989,6 +988,7 @@ struct kernfs_root *kernfs_create_root(struct kernfs_syscall_ops *scops,
return ERR_PTR(-ENOMEM);
idr_init(&root->ino_idr);
spin_lock_init(&root->kernfs_idr_lock);
init_rwsem(&root->kernfs_rwsem);
init_rwsem(&root->kernfs_iattr_rwsem);
init_rwsem(&root->kernfs_supers_rwsem);

1
fs/kernfs/kernfs-internal.h
View File

@ -40,6 +40,7 @@ struct kernfs_root {
/* private fields, do not use outside kernfs proper */
struct idr ino_idr;
spinlock_t kernfs_idr_lock; /* root->ino_idr */
u32 last_id_lowbits;
u32 id_highbits;
struct kernfs_syscall_ops *syscall_ops;