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sanitize ecryptfs ->mount()

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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>
This commit is contained in:
Al Viro 2011-01-12 20:04:37 -05:00
parent d61dcce297
commit 66cb76666d
2 changed files with 70 additions and 90 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

1
fs/ecryptfs/inode.c
View file

@ -441,7 +441,6 @@ static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
struct qstr lower_name;
int rc = 0;
d_set_d_op(ecryptfs_dentry, &ecryptfs_dops);
if ((ecryptfs_dentry->d_name.len == 1
&& !strcmp(ecryptfs_dentry->d_name.name, "."))
|| (ecryptfs_dentry->d_name.len == 2

159
fs/ecryptfs/main.c
View file

@ -141,21 +141,9 @@ int ecryptfs_init_persistent_file(struct dentry *ecryptfs_dentry)
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 @@ int ecryptfs_interpose(struct dentry *lower_dentry, struct dentry *dentry,
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,
@ -491,60 +500,12 @@ static int ecryptfs_parse_options(struct ecryptfs_sb_info *sbi, char *options)
struct kmem_cache *ecryptfs_sb_info_cache;
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 @@ static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags
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 @@ static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags
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 @@ static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags
/* ->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);