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Diffstat (limited to 'fs/fs_struct.c')
-rw-r--r--fs/fs_struct.c36
1 files changed, 26 insertions, 10 deletions
diff --git a/fs/fs_struct.c b/fs/fs_struct.c
index ed45a9cf5f3d..68ca487bedb1 100644
--- a/fs/fs_struct.c
+++ b/fs/fs_struct.c
@@ -14,12 +14,14 @@ void set_fs_root(struct fs_struct *fs, struct path *path)
struct path old_root;
spin_lock(&fs->lock);
+ write_seqcount_begin(&fs->seq);
old_root = fs->root;
fs->root = *path;
- path_get(path);
+ path_get_long(path);
+ write_seqcount_end(&fs->seq);
spin_unlock(&fs->lock);
if (old_root.dentry)
- path_put(&old_root);
+ path_put_long(&old_root);
}
/*
@@ -31,13 +33,15 @@ void set_fs_pwd(struct fs_struct *fs, struct path *path)
struct path old_pwd;
spin_lock(&fs->lock);
+ write_seqcount_begin(&fs->seq);
old_pwd = fs->pwd;
fs->pwd = *path;
- path_get(path);
+ path_get_long(path);
+ write_seqcount_end(&fs->seq);
spin_unlock(&fs->lock);
if (old_pwd.dentry)
- path_put(&old_pwd);
+ path_put_long(&old_pwd);
}
void chroot_fs_refs(struct path *old_root, struct path *new_root)
@@ -52,31 +56,33 @@ void chroot_fs_refs(struct path *old_root, struct path *new_root)
fs = p->fs;
if (fs) {
spin_lock(&fs->lock);
+ write_seqcount_begin(&fs->seq);
if (fs->root.dentry == old_root->dentry
&& fs->root.mnt == old_root->mnt) {
- path_get(new_root);
+ path_get_long(new_root);
fs->root = *new_root;
count++;
}
if (fs->pwd.dentry == old_root->dentry
&& fs->pwd.mnt == old_root->mnt) {
- path_get(new_root);
+ path_get_long(new_root);
fs->pwd = *new_root;
count++;
}
+ write_seqcount_end(&fs->seq);
spin_unlock(&fs->lock);
}
task_unlock(p);
} while_each_thread(g, p);
read_unlock(&tasklist_lock);
while (count--)
- path_put(old_root);
+ path_put_long(old_root);
}
void free_fs_struct(struct fs_struct *fs)
{
- path_put(&fs->root);
- path_put(&fs->pwd);
+ path_put_long(&fs->root);
+ path_put_long(&fs->pwd);
kmem_cache_free(fs_cachep, fs);
}
@@ -88,8 +94,10 @@ void exit_fs(struct task_struct *tsk)
int kill;
task_lock(tsk);
spin_lock(&fs->lock);
+ write_seqcount_begin(&fs->seq);
tsk->fs = NULL;
kill = !--fs->users;
+ write_seqcount_end(&fs->seq);
spin_unlock(&fs->lock);
task_unlock(tsk);
if (kill)
@@ -105,8 +113,15 @@ struct fs_struct *copy_fs_struct(struct fs_struct *old)
fs->users = 1;
fs->in_exec = 0;
spin_lock_init(&fs->lock);
+ seqcount_init(&fs->seq);
fs->umask = old->umask;
- get_fs_root_and_pwd(old, &fs->root, &fs->pwd);
+
+ spin_lock(&old->lock);
+ fs->root = old->root;
+ path_get_long(&fs->root);
+ fs->pwd = old->pwd;
+ path_get_long(&fs->pwd);
+ spin_unlock(&old->lock);
}
return fs;
}
@@ -144,6 +159,7 @@ EXPORT_SYMBOL(current_umask);
struct fs_struct init_fs = {
.users = 1,
.lock = __SPIN_LOCK_UNLOCKED(init_fs.lock),
+ .seq = SEQCNT_ZERO,
.umask = 0022,
};