sanitize ecryptfs ->mount()
kill ecryptfs_read_super(), reorder code allowing to use
normal d_alloc_root() instead of opencoding it.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c
index 3510386..9ed4769 100644
--- a/fs/ecryptfs/main.c
+++ b/fs/ecryptfs/main.c
@@ -141,21 +141,9 @@
return rc;
}
-/**
- * ecryptfs_interpose
- * @lower_dentry: Existing dentry in the lower filesystem
- * @dentry: ecryptfs' dentry
- * @sb: ecryptfs's super_block
- * @flags: flags to govern behavior of interpose procedure
- *
- * Interposes upper and lower dentries.
- *
- * Returns zero on success; non-zero otherwise
- */
-int ecryptfs_interpose(struct dentry *lower_dentry, struct dentry *dentry,
- struct super_block *sb, u32 flags)
+static inode *ecryptfs_get_inode(struct inode *lower_inode,
+ struct super_block *sb)
{
- struct inode *lower_inode;
struct inode *inode;
int rc = 0;
@@ -189,17 +177,38 @@
if (special_file(lower_inode->i_mode))
init_special_inode(inode, lower_inode->i_mode,
lower_inode->i_rdev);
- d_set_d_op(dentry, &ecryptfs_dops);
fsstack_copy_attr_all(inode, lower_inode);
/* This size will be overwritten for real files w/ headers and
* other metadata */
fsstack_copy_inode_size(inode, lower_inode);
+ return inode;
+out:
+ return ERR_PTR(rc);
+}
+
+/**
+ * ecryptfs_interpose
+ * @lower_dentry: Existing dentry in the lower filesystem
+ * @dentry: ecryptfs' dentry
+ * @sb: ecryptfs's super_block
+ * @flags: flags to govern behavior of interpose procedure
+ *
+ * Interposes upper and lower dentries.
+ *
+ * Returns zero on success; non-zero otherwise
+ */
+int ecryptfs_interpose(struct dentry *lower_dentry, struct dentry *dentry,
+ struct super_block *sb, u32 flags)
+{
+ struct inode *lower_inode = lower_dentry->d_inode;
+ struct inode *inode = ecryptfs_get_inode(lower_inode, sb);
+ if (IS_ERR(inode)
+ return PTR_ERR(inode);
if (flags & ECRYPTFS_INTERPOSE_FLAG_D_ADD)
d_add(dentry, inode);
else
d_instantiate(dentry, inode);
-out:
- return rc;
+ return 0;
}
enum { ecryptfs_opt_sig, ecryptfs_opt_ecryptfs_sig,
@@ -492,59 +501,11 @@
static struct file_system_type ecryptfs_fs_type;
/**
- * ecryptfs_read_super
- * @sb: The ecryptfs super block
- * @dev_name: The path to mount over
- *
- * Read the super block of the lower filesystem, and use
- * ecryptfs_interpose to create our initial inode and super block
- * struct.
- */
-static int ecryptfs_read_super(struct super_block *sb, const char *dev_name)
-{
- struct path path;
- int rc;
-
- rc = kern_path(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path);
- if (rc) {
- ecryptfs_printk(KERN_WARNING, "path_lookup() failed\n");
- goto out;
- }
- if (path.dentry->d_sb->s_type == &ecryptfs_fs_type) {
- rc = -EINVAL;
- printk(KERN_ERR "Mount on filesystem of type "
- "eCryptfs explicitly disallowed due to "
- "known incompatibilities\n");
- goto out_free;
- }
- ecryptfs_set_superblock_lower(sb, path.dentry->d_sb);
- sb->s_maxbytes = path.dentry->d_sb->s_maxbytes;
- sb->s_blocksize = path.dentry->d_sb->s_blocksize;
- ecryptfs_set_dentry_lower(sb->s_root, path.dentry);
- ecryptfs_set_dentry_lower_mnt(sb->s_root, path.mnt);
- rc = ecryptfs_interpose(path.dentry, sb->s_root, sb, 0);
- if (rc)
- goto out_free;
- rc = 0;
- goto out;
-out_free:
- path_put(&path);
-out:
- return rc;
-}
-
-/**
* ecryptfs_get_sb
* @fs_type
* @flags
* @dev_name: The path to mount over
* @raw_data: The options passed into the kernel
- *
- * The whole ecryptfs_get_sb process is broken into 3 functions:
- * ecryptfs_parse_options(): handle options passed to ecryptfs, if any
- * ecryptfs_read_super(): this accesses the lower filesystem and uses
- * ecryptfs_interpose to perform most of the linking
- * ecryptfs_interpose(): links the lower filesystem into ecryptfs (inode.c)
*/
static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags,
const char *dev_name, void *raw_data)
@@ -553,6 +514,8 @@
struct ecryptfs_sb_info *sbi;
struct ecryptfs_dentry_info *root_info;
const char *err = "Getting sb failed";
+ struct inode *inode;
+ struct path path;
int rc;
sbi = kmem_cache_zalloc(ecryptfs_sb_info_cache, GFP_KERNEL);
@@ -575,10 +538,8 @@
s->s_flags = flags;
rc = bdi_setup_and_register(&sbi->bdi, "ecryptfs", BDI_CAP_MAP_COPY);
- if (rc) {
- deactivate_locked_super(s);
- goto out;
- }
+ if (rc)
+ goto out1;
ecryptfs_set_superblock_private(s, sbi);
s->s_bdi = &sbi->bdi;
@@ -586,34 +547,54 @@
/* ->kill_sb() will take care of sbi after that point */
sbi = NULL;
s->s_op = &ecryptfs_sops;
+ s->s_d_op = &ecryptfs_dops;
+
+ err = "Reading sb failed";
+ rc = kern_path(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path);
+ if (rc) {
+ ecryptfs_printk(KERN_WARNING, "kern_path() failed\n");
+ goto out1;
+ }
+ if (path.dentry->d_sb->s_type == &ecryptfs_fs_type) {
+ rc = -EINVAL;
+ printk(KERN_ERR "Mount on filesystem of type "
+ "eCryptfs explicitly disallowed due to "
+ "known incompatibilities\n");
+ goto out_free;
+ }
+ ecryptfs_set_superblock_lower(s, path.dentry->d_sb);
+ s->s_maxbytes = path.dentry->d_sb->s_maxbytes;
+ s->s_blocksize = path.dentry->d_sb->s_blocksize;
+
+ inode = ecryptfs_get_inode(path.dentry->d_inode, s);
+ rc = PTR_ERR(inode);
+ if (IS_ERR(inode))
+ goto out_free;
+
+ s->s_root = d_alloc_root(inode);
+ if (!s->s_root) {
+ iput(inode);
+ rc = -ENOMEM;
+ goto out_free;
+ }
rc = -ENOMEM;
- s->s_root = d_alloc(NULL, &(const struct qstr) {
- .hash = 0,.name = "/",.len = 1});
- if (!s->s_root) {
- deactivate_locked_super(s);
- goto out;
- }
- d_set_d_op(s->s_root, &ecryptfs_dops);
- s->s_root->d_sb = s;
- s->s_root->d_parent = s->s_root;
-
root_info = kmem_cache_zalloc(ecryptfs_dentry_info_cache, GFP_KERNEL);
- if (!root_info) {
- deactivate_locked_super(s);
- goto out;
- }
+ if (!root_info)
+ goto out_free;
+
/* ->kill_sb() will take care of root_info */
ecryptfs_set_dentry_private(s->s_root, root_info);
+ ecryptfs_set_dentry_lower(s->s_root, path.dentry);
+ ecryptfs_set_dentry_lower_mnt(s->s_root, path.mnt);
+
s->s_flags |= MS_ACTIVE;
- rc = ecryptfs_read_super(s, dev_name);
- if (rc) {
- deactivate_locked_super(s);
- err = "Reading sb failed";
- goto out;
- }
return dget(s->s_root);
+out_free:
+ path_put(&path);
+out1:
+ deactivate_locked_super(s);
out:
if (sbi) {
ecryptfs_destroy_mount_crypt_stat(&sbi->mount_crypt_stat);