get rid of ->mnt_longterm

it's enough to set ->mnt_ns of internal vfsmounts to something
distinct from all struct mnt_namespace out there; then we can
just use the check for ->mnt_ns != NULL in the fast path of
mntput_no_expire()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro
2012-06-09 00:59:08 -04:00
parent d187663ef2
commit f7a99c5b7c
5 changed files with 26 additions and 72 deletions

View File

@@ -6,18 +6,6 @@
#include <linux/fs_struct.h>
#include "internal.h"
static inline void path_get_longterm(struct path *path)
{
path_get(path);
mnt_make_longterm(path->mnt);
}
static inline void path_put_longterm(struct path *path)
{
mnt_make_shortterm(path->mnt);
path_put(path);
}
/*
* Replace the fs->{rootmnt,root} with {mnt,dentry}. Put the old values.
* It can block.
@@ -26,7 +14,7 @@ void set_fs_root(struct fs_struct *fs, struct path *path)
{
struct path old_root;
path_get_longterm(path);
path_get(path);
spin_lock(&fs->lock);
write_seqcount_begin(&fs->seq);
old_root = fs->root;
@@ -34,7 +22,7 @@ void set_fs_root(struct fs_struct *fs, struct path *path)
write_seqcount_end(&fs->seq);
spin_unlock(&fs->lock);
if (old_root.dentry)
path_put_longterm(&old_root);
path_put(&old_root);
}
/*
@@ -45,7 +33,7 @@ void set_fs_pwd(struct fs_struct *fs, struct path *path)
{
struct path old_pwd;
path_get_longterm(path);
path_get(path);
spin_lock(&fs->lock);
write_seqcount_begin(&fs->seq);
old_pwd = fs->pwd;
@@ -54,7 +42,7 @@ void set_fs_pwd(struct fs_struct *fs, struct path *path)
spin_unlock(&fs->lock);
if (old_pwd.dentry)
path_put_longterm(&old_pwd);
path_put(&old_pwd);
}
static inline int replace_path(struct path *p, const struct path *old, const struct path *new)
@@ -84,7 +72,7 @@ void chroot_fs_refs(struct path *old_root, struct path *new_root)
write_seqcount_end(&fs->seq);
while (hits--) {
count++;
path_get_longterm(new_root);
path_get(new_root);
}
spin_unlock(&fs->lock);
}
@@ -92,13 +80,13 @@ void chroot_fs_refs(struct path *old_root, struct path *new_root)
} while_each_thread(g, p);
read_unlock(&tasklist_lock);
while (count--)
path_put_longterm(old_root);
path_put(old_root);
}
void free_fs_struct(struct fs_struct *fs)
{
path_put_longterm(&fs->root);
path_put_longterm(&fs->pwd);
path_put(&fs->root);
path_put(&fs->pwd);
kmem_cache_free(fs_cachep, fs);
}
@@ -132,9 +120,9 @@ struct fs_struct *copy_fs_struct(struct fs_struct *old)
spin_lock(&old->lock);
fs->root = old->root;
path_get_longterm(&fs->root);
path_get(&fs->root);
fs->pwd = old->pwd;
path_get_longterm(&fs->pwd);
path_get(&fs->pwd);
spin_unlock(&old->lock);
}
return fs;