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authorIan Kent2021-07-16 17:28:29 +0800
committerGreg Kroah-Hartman2021-07-27 09:29:15 +0200
commit7ba0273b2f34a55efe967d3c7381fb1da2ca195f (patch)
treeb8c0df46d2918cd7fc27c87fa1f9e058bbfd6aeb /fs/kernfs/mount.c
parentc7e7c04274b13f98f758fb69b03f2ab61976ea80 (diff)
kernfs: switch kernfs to use an rwsem
The kernfs global lock restricts the ability to perform kernfs node lookup operations in parallel during path walks. Change the kernfs mutex to an rwsem so that, when opportunity arises, node searches can be done in parallel with path walk lookups. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Ian Kent <raven@themaw.net> Link: https://lore.kernel.org/r/162642770946.63632.2218304587223241374.stgit@web.messagingengine.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/kernfs/mount.c')
-rw-r--r--fs/kernfs/mount.c12
1 files changed, 6 insertions, 6 deletions
diff --git a/fs/kernfs/mount.c b/fs/kernfs/mount.c
index 9dc7e7a64e10..baa4155ba2ed 100644
--- a/fs/kernfs/mount.c
+++ b/fs/kernfs/mount.c
@@ -255,9 +255,9 @@ static int kernfs_fill_super(struct super_block *sb, struct kernfs_fs_context *k
sb->s_shrink.seeks = 0;
/* get root inode, initialize and unlock it */
- mutex_lock(&kernfs_mutex);
+ down_write(&kernfs_rwsem);
inode = kernfs_get_inode(sb, info->root->kn);
- mutex_unlock(&kernfs_mutex);
+ up_write(&kernfs_rwsem);
if (!inode) {
pr_debug("kernfs: could not get root inode\n");
return -ENOMEM;
@@ -344,9 +344,9 @@ int kernfs_get_tree(struct fs_context *fc)
}
sb->s_flags |= SB_ACTIVE;
- mutex_lock(&kernfs_mutex);
+ down_write(&kernfs_rwsem);
list_add(&info->node, &info->root->supers);
- mutex_unlock(&kernfs_mutex);
+ up_write(&kernfs_rwsem);
}
fc->root = dget(sb->s_root);
@@ -372,9 +372,9 @@ void kernfs_kill_sb(struct super_block *sb)
{
struct kernfs_super_info *info = kernfs_info(sb);
- mutex_lock(&kernfs_mutex);
+ down_write(&kernfs_rwsem);
list_del(&info->node);
- mutex_unlock(&kernfs_mutex);
+ up_write(&kernfs_rwsem);
/*
* Remove the superblock from fs_supers/s_instances