linux-master/fs/fs_struct.c

5 #include <linux/fs.h>
12  * Replace the fs->{rootmnt,root} with {mnt,dentry}. Put the old values.
15 void set_fs_root(struct fs_struct *fs, const struct path *path)
20 	spin_lock(&fs->lock);
21 	write_seqcount_begin(&fs->seq);
22 	old_root = fs->root;
23 	fs->root = *path;
24 	write_seqcount_end(&fs->seq);
25 	spin_unlock(&fs->lock);
31  * Replace the fs->{pwdmnt,pwd} with {mnt,dentry}. Put the old values.
34 void set_fs_pwd(struct fs_struct *fs, const struct path *path)
39 	spin_lock(&fs->lock);
40 	write_seqcount_begin(&fs->seq);
41 	old_pwd = fs->pwd;
42 	fs->pwd = *path;
43 	write_seqcount_end(&fs->seq);
44 	spin_unlock(&fs->lock);
61 	struct fs_struct *fs;
67 		fs = p->fs;
68 		if (fs) {
70 			spin_lock(&fs->lock);
71 			write_seqcount_begin(&fs->seq);
72 			hits += replace_path(&fs->root, old_root, new_root);
73 			hits += replace_path(&fs->pwd, old_root, new_root);
74 			write_seqcount_end(&fs->seq);
79 			spin_unlock(&fs->lock);
88 void free_fs_struct(struct fs_struct *fs)
90 	path_put(&fs->root);
91 	path_put(&fs->pwd);
92 	kmem_cache_free(fs_cachep, fs);
97 	struct fs_struct *fs = tsk->fs;
99 	if (fs) {
102 		spin_lock(&fs->lock);
103 		tsk->fs = NULL;
104 		kill = !--fs->users;
105 		spin_unlock(&fs->lock);
108 			free_fs_struct(fs);
114 	struct fs_struct *fs = kmem_cache_alloc(fs_cachep, GFP_KERNEL);
115 	/* We don't need to lock fs - think why ;-) */
116 	if (fs) {
117 		fs->users = 1;
118 		fs->in_exec = 0;
119 		spin_lock_init(&fs->lock);
120 		seqcount_spinlock_init(&fs->seq, &fs->lock);
121 		fs->umask = old->umask;
124 		fs->root = old->root;
125 		path_get(&fs->root);
126 		fs->pwd = old->pwd;
127 		path_get(&fs->pwd);
130 	return fs;
135 	struct fs_struct *fs = current->fs;
136 	struct fs_struct *new_fs = copy_fs_struct(fs);
143 	spin_lock(&fs->lock);
144 	kill = !--fs->users;
145 	current->fs = new_fs;
146 	spin_unlock(&fs->lock);
150 		free_fs_struct(fs);
158 	return current->fs->umask;