Commit 66cb7666 authored by Al Viro's avatar Al Viro

sanitize ecryptfs ->mount()

kill ecryptfs_read_super(), reorder code allowing to use
normal d_alloc_root() instead of opencoding it.
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent d61dcce2
...@@ -441,7 +441,6 @@ static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode, ...@@ -441,7 +441,6 @@ static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
struct qstr lower_name; struct qstr lower_name;
int rc = 0; int rc = 0;
d_set_d_op(ecryptfs_dentry, &ecryptfs_dops);
if ((ecryptfs_dentry->d_name.len == 1 if ((ecryptfs_dentry->d_name.len == 1
&& !strcmp(ecryptfs_dentry->d_name.name, ".")) && !strcmp(ecryptfs_dentry->d_name.name, "."))
|| (ecryptfs_dentry->d_name.len == 2 || (ecryptfs_dentry->d_name.len == 2
......
...@@ -141,21 +141,9 @@ int ecryptfs_init_persistent_file(struct dentry *ecryptfs_dentry) ...@@ -141,21 +141,9 @@ int ecryptfs_init_persistent_file(struct dentry *ecryptfs_dentry)
return rc; return rc;
} }
/** static inode *ecryptfs_get_inode(struct inode *lower_inode,
* ecryptfs_interpose struct super_block *sb)
* @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;
struct inode *inode; struct inode *inode;
int rc = 0; int rc = 0;
...@@ -189,17 +177,38 @@ int ecryptfs_interpose(struct dentry *lower_dentry, struct dentry *dentry, ...@@ -189,17 +177,38 @@ int ecryptfs_interpose(struct dentry *lower_dentry, struct dentry *dentry,
if (special_file(lower_inode->i_mode)) if (special_file(lower_inode->i_mode))
init_special_inode(inode, lower_inode->i_mode, init_special_inode(inode, lower_inode->i_mode,
lower_inode->i_rdev); lower_inode->i_rdev);
d_set_d_op(dentry, &ecryptfs_dops);
fsstack_copy_attr_all(inode, lower_inode); fsstack_copy_attr_all(inode, lower_inode);
/* This size will be overwritten for real files w/ headers and /* This size will be overwritten for real files w/ headers and
* other metadata */ * other metadata */
fsstack_copy_inode_size(inode, lower_inode); 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) if (flags & ECRYPTFS_INTERPOSE_FLAG_D_ADD)
d_add(dentry, inode); d_add(dentry, inode);
else else
d_instantiate(dentry, inode); d_instantiate(dentry, inode);
out: return 0;
return rc;
} }
enum { ecryptfs_opt_sig, ecryptfs_opt_ecryptfs_sig, enum { ecryptfs_opt_sig, ecryptfs_opt_ecryptfs_sig,
...@@ -491,60 +500,12 @@ static int ecryptfs_parse_options(struct ecryptfs_sb_info *sbi, char *options) ...@@ -491,60 +500,12 @@ static int ecryptfs_parse_options(struct ecryptfs_sb_info *sbi, char *options)
struct kmem_cache *ecryptfs_sb_info_cache; struct kmem_cache *ecryptfs_sb_info_cache;
static struct file_system_type ecryptfs_fs_type; 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 * ecryptfs_get_sb
* @fs_type * @fs_type
* @flags * @flags
* @dev_name: The path to mount over * @dev_name: The path to mount over
* @raw_data: The options passed into the kernel * @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, static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags,
const char *dev_name, void *raw_data) const char *dev_name, void *raw_data)
...@@ -553,6 +514,8 @@ static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags ...@@ -553,6 +514,8 @@ static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags
struct ecryptfs_sb_info *sbi; struct ecryptfs_sb_info *sbi;
struct ecryptfs_dentry_info *root_info; struct ecryptfs_dentry_info *root_info;
const char *err = "Getting sb failed"; const char *err = "Getting sb failed";
struct inode *inode;
struct path path;
int rc; int rc;
sbi = kmem_cache_zalloc(ecryptfs_sb_info_cache, GFP_KERNEL); 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 ...@@ -575,10 +538,8 @@ static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags
s->s_flags = flags; s->s_flags = flags;
rc = bdi_setup_and_register(&sbi->bdi, "ecryptfs", BDI_CAP_MAP_COPY); rc = bdi_setup_and_register(&sbi->bdi, "ecryptfs", BDI_CAP_MAP_COPY);
if (rc) { if (rc)
deactivate_locked_super(s); goto out1;
goto out;
}
ecryptfs_set_superblock_private(s, sbi); ecryptfs_set_superblock_private(s, sbi);
s->s_bdi = &sbi->bdi; s->s_bdi = &sbi->bdi;
...@@ -586,34 +547,54 @@ static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags ...@@ -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 */ /* ->kill_sb() will take care of sbi after that point */
sbi = NULL; sbi = NULL;
s->s_op = &ecryptfs_sops; s->s_op = &ecryptfs_sops;
s->s_d_op = &ecryptfs_dops;
rc = -ENOMEM; err = "Reading sb failed";
s->s_root = d_alloc(NULL, &(const struct qstr) { rc = kern_path(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path);
.hash = 0,.name = "/",.len = 1}); 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) { if (!s->s_root) {
deactivate_locked_super(s); iput(inode);
goto out; rc = -ENOMEM;
goto out_free;
} }
d_set_d_op(s->s_root, &ecryptfs_dops);
s->s_root->d_sb = s;
s->s_root->d_parent = s->s_root;
rc = -ENOMEM;
root_info = kmem_cache_zalloc(ecryptfs_dentry_info_cache, GFP_KERNEL); root_info = kmem_cache_zalloc(ecryptfs_dentry_info_cache, GFP_KERNEL);
if (!root_info) { if (!root_info)
deactivate_locked_super(s); goto out_free;
goto out;
}
/* ->kill_sb() will take care of root_info */ /* ->kill_sb() will take care of root_info */
ecryptfs_set_dentry_private(s->s_root, 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; 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); return dget(s->s_root);
out_free:
path_put(&path);
out1:
deactivate_locked_super(s);
out: out:
if (sbi) { if (sbi) {
ecryptfs_destroy_mount_crypt_stat(&sbi->mount_crypt_stat); ecryptfs_destroy_mount_crypt_stat(&sbi->mount_crypt_stat);
......
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