[PATCH] assorted path_lookup() -> kern_path() conversions
[safe/jmp/linux-2.6] / fs / ecryptfs / main.c
index 4954595..64d2ba9 100644 (file)
@@ -30,9 +30,7 @@
 #include <linux/namei.h>
 #include <linux/skbuff.h>
 #include <linux/crypto.h>
-#include <linux/netlink.h>
 #include <linux/mount.h>
-#include <linux/dcache.h>
 #include <linux/pagemap.h>
 #include <linux/key.h>
 #include <linux/parser.h>
@@ -50,8 +48,7 @@ MODULE_PARM_DESC(ecryptfs_verbosity,
                 "0, which is Quiet)");
 
 /**
- * Module parameter that defines the number of netlink message buffer
- * elements
+ * Module parameter that defines the number of message buffer elements
  */
 unsigned int ecryptfs_message_buf_len = ECRYPTFS_DEFAULT_MSG_CTX_ELEMS;
 
@@ -61,9 +58,9 @@ MODULE_PARM_DESC(ecryptfs_message_buf_len,
 
 /**
  * Module parameter that defines the maximum guaranteed amount of time to wait
- * for a response through netlink.  The actual sleep time will be, more than
+ * for a response from ecryptfsd.  The actual sleep time will be, more than
  * likely, a small amount greater than this specified value, but only less if
- * the netlink message successfully arrives.
+ * the message successfully arrives.
  */
 signed long ecryptfs_message_wait_timeout = ECRYPTFS_MAX_MSG_CTX_TTL / HZ;
 
@@ -84,8 +81,6 @@ module_param(ecryptfs_number_of_users, uint, 0);
 MODULE_PARM_DESC(ecryptfs_number_of_users, "An estimate of the number of "
                 "concurrent users of eCryptfs");
 
-unsigned int ecryptfs_transport = ECRYPTFS_DEFAULT_TRANSPORT;
-
 void __ecryptfs_printk(const char *fmt, ...)
 {
        va_list args;
@@ -99,18 +94,65 @@ void __ecryptfs_printk(const char *fmt, ...)
 }
 
 /**
+ * ecryptfs_init_persistent_file
+ * @ecryptfs_dentry: Fully initialized eCryptfs dentry object, with
+ *                   the lower dentry and the lower mount set
+ *
+ * eCryptfs only ever keeps a single open file for every lower
+ * inode. All I/O operations to the lower inode occur through that
+ * file. When the first eCryptfs dentry that interposes with the first
+ * lower dentry for that inode is created, this function creates the
+ * persistent file struct and associates it with the eCryptfs
+ * inode. When the eCryptfs inode is destroyed, the file is closed.
+ *
+ * The persistent file will be opened with read/write permissions, if
+ * possible. Otherwise, it is opened read-only.
+ *
+ * This function does nothing if a lower persistent file is already
+ * associated with the eCryptfs inode.
+ *
+ * Returns zero on success; non-zero otherwise
+ */
+int ecryptfs_init_persistent_file(struct dentry *ecryptfs_dentry)
+{
+       struct ecryptfs_inode_info *inode_info =
+               ecryptfs_inode_to_private(ecryptfs_dentry->d_inode);
+       int rc = 0;
+
+       mutex_lock(&inode_info->lower_file_mutex);
+       if (!inode_info->lower_file) {
+               struct dentry *lower_dentry;
+               struct vfsmount *lower_mnt =
+                       ecryptfs_dentry_to_lower_mnt(ecryptfs_dentry);
+
+               lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
+               rc = ecryptfs_privileged_open(&inode_info->lower_file,
+                                                    lower_dentry, lower_mnt);
+               if (rc || IS_ERR(inode_info->lower_file)) {
+                       printk(KERN_ERR "Error opening lower persistent file "
+                              "for lower_dentry [0x%p] and lower_mnt [0x%p]; "
+                              "rc = [%d]\n", lower_dentry, lower_mnt, rc);
+                       rc = PTR_ERR(inode_info->lower_file);
+                       inode_info->lower_file = NULL;
+               }
+       }
+       mutex_unlock(&inode_info->lower_file_mutex);
+       return rc;
+}
+
+/**
  * ecryptfs_interpose
  * @lower_dentry: Existing dentry in the lower filesystem
  * @dentry: ecryptfs' dentry
  * @sb: ecryptfs's super_block
- * @flag: If set to true, then d_add is called, else d_instantiate is called
+ * @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, int flag)
+                      struct super_block *sb, u32 flags)
 {
        struct inode *lower_inode;
        struct inode *inode;
@@ -147,7 +189,7 @@ int ecryptfs_interpose(struct dentry *lower_dentry, struct dentry *dentry,
                init_special_inode(inode, lower_inode->i_mode,
                                   lower_inode->i_rdev);
        dentry->d_op = &ecryptfs_dops;
-       if (flag)
+       if (flags & ECRYPTFS_INTERPOSE_FLAG_D_ADD)
                d_add(dentry, inode);
        else
                d_instantiate(dentry, inode);
@@ -159,17 +201,15 @@ out:
        return rc;
 }
 
-enum { ecryptfs_opt_sig, ecryptfs_opt_ecryptfs_sig, ecryptfs_opt_debug,
-       ecryptfs_opt_ecryptfs_debug, ecryptfs_opt_cipher,
-       ecryptfs_opt_ecryptfs_cipher, ecryptfs_opt_ecryptfs_key_bytes,
+enum { ecryptfs_opt_sig, ecryptfs_opt_ecryptfs_sig,
+       ecryptfs_opt_cipher, ecryptfs_opt_ecryptfs_cipher,
+       ecryptfs_opt_ecryptfs_key_bytes,
        ecryptfs_opt_passthrough, ecryptfs_opt_xattr_metadata,
        ecryptfs_opt_encrypted_view, ecryptfs_opt_err };
 
-static match_table_t tokens = {
+static const match_table_t tokens = {
        {ecryptfs_opt_sig, "sig=%s"},
        {ecryptfs_opt_ecryptfs_sig, "ecryptfs_sig=%s"},
-       {ecryptfs_opt_debug, "debug=%u"},
-       {ecryptfs_opt_ecryptfs_debug, "ecryptfs_debug=%u"},
        {ecryptfs_opt_cipher, "cipher=%s"},
        {ecryptfs_opt_ecryptfs_cipher, "ecryptfs_cipher=%s"},
        {ecryptfs_opt_ecryptfs_key_bytes, "ecryptfs_key_bytes=%u"},
@@ -197,10 +237,11 @@ static int ecryptfs_init_global_auth_toks(
                               "session keyring for sig specified in mount "
                               "option: [%s]\n", global_auth_tok->sig);
                        global_auth_tok->flags |= ECRYPTFS_AUTH_TOK_INVALID;
-                       rc = 0;
+                       goto out;
                } else
                        global_auth_tok->flags &= ~ECRYPTFS_AUTH_TOK_INVALID;
        }
+out:
        return rc;
 }
 
@@ -246,11 +287,9 @@ static int ecryptfs_parse_options(struct super_block *sb, char *options)
        substring_t args[MAX_OPT_ARGS];
        int token;
        char *sig_src;
-       char *debug_src;
        char *cipher_name_dst;
        char *cipher_name_src;
        char *cipher_key_bytes_src;
-       int cipher_name_len;
 
        if (!options) {
                rc = -EINVAL;
@@ -274,16 +313,6 @@ static int ecryptfs_parse_options(struct super_block *sb, char *options)
                        }
                        sig_set = 1;
                        break;
-               case ecryptfs_opt_debug:
-               case ecryptfs_opt_ecryptfs_debug:
-                       debug_src = args[0].from;
-                       ecryptfs_verbosity =
-                               (int)simple_strtol(debug_src, &debug_src,
-                                                  0);
-                       ecryptfs_printk(KERN_DEBUG,
-                                       "Verbosity set to [%d]" "\n",
-                                       ecryptfs_verbosity);
-                       break;
                case ecryptfs_opt_cipher:
                case ecryptfs_opt_ecryptfs_cipher:
                        cipher_name_src = args[0].from;
@@ -341,24 +370,23 @@ static int ecryptfs_parse_options(struct super_block *sb, char *options)
                goto out;
        }
        if (!cipher_name_set) {
-               cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER);
-               if (unlikely(cipher_name_len
-                            >= ECRYPTFS_MAX_CIPHER_NAME_SIZE)) {
-                       rc = -EINVAL;
-                       BUG();
-                       goto out;
-               }
-               memcpy(mount_crypt_stat->global_default_cipher_name,
-                      ECRYPTFS_DEFAULT_CIPHER, cipher_name_len);
-               mount_crypt_stat->global_default_cipher_name[cipher_name_len]
-                   = '\0';
+               int cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER);
+
+               BUG_ON(cipher_name_len >= ECRYPTFS_MAX_CIPHER_NAME_SIZE);
+
+               strcpy(mount_crypt_stat->global_default_cipher_name,
+                      ECRYPTFS_DEFAULT_CIPHER);
        }
        if (!cipher_key_bytes_set) {
                mount_crypt_stat->global_default_cipher_key_size = 0;
        }
-       rc = ecryptfs_add_new_key_tfm(
-               NULL, mount_crypt_stat->global_default_cipher_name,
-               mount_crypt_stat->global_default_cipher_key_size);
+       mutex_lock(&key_tfm_list_mutex);
+       if (!ecryptfs_tfm_exists(mount_crypt_stat->global_default_cipher_name,
+                                NULL))
+               rc = ecryptfs_add_new_key_tfm(
+                       NULL, mount_crypt_stat->global_default_cipher_name,
+                       mount_crypt_stat->global_default_cipher_key_size);
+       mutex_unlock(&key_tfm_list_mutex);
        if (rc) {
                printk(KERN_ERR "Error attempting to initialize cipher with "
                       "name = [%s] and key size = [%td]; rc = [%d]\n",
@@ -372,7 +400,6 @@ static int ecryptfs_parse_options(struct super_block *sb, char *options)
                printk(KERN_WARNING "One or more global auth toks could not "
                       "properly register; rc = [%d]\n", rc);
        }
-       rc = 0;
 out:
        return rc;
 }
@@ -444,30 +471,26 @@ out:
  */
 static int ecryptfs_read_super(struct super_block *sb, const char *dev_name)
 {
+       struct path path;
        int rc;
-       struct nameidata nd;
-       struct dentry *lower_root;
-       struct vfsmount *lower_mnt;
 
-       memset(&nd, 0, sizeof(struct nameidata));
-       rc = path_lookup(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &nd);
+       rc = kern_path(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path);
        if (rc) {
                ecryptfs_printk(KERN_WARNING, "path_lookup() failed\n");
                goto out;
        }
-       lower_root = nd.dentry;
-       lower_mnt = nd.mnt;
-       ecryptfs_set_superblock_lower(sb, lower_root->d_sb);
-       sb->s_maxbytes = lower_root->d_sb->s_maxbytes;
-       ecryptfs_set_dentry_lower(sb->s_root, lower_root);
-       ecryptfs_set_dentry_lower_mnt(sb->s_root, lower_mnt);
-       rc = ecryptfs_interpose(lower_root, sb->s_root, sb, 0);
+       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_release(&nd);
+       path_put(&path);
 out:
        return rc;
 }
@@ -546,7 +569,7 @@ static struct file_system_type ecryptfs_fs_type = {
  * Initializes the ecryptfs_inode_info_cache when it is created
  */
 static void
-inode_info_init_once(void *vptr, struct kmem_cache *cachep, unsigned long flags)
+inode_info_init_once(void *vptr)
 {
        struct ecryptfs_inode_info *ei = (struct ecryptfs_inode_info *)vptr;
 
@@ -557,7 +580,7 @@ static struct ecryptfs_cache_info {
        struct kmem_cache **cache;
        const char *name;
        size_t size;
-       void (*ctor)(void*, struct kmem_cache *, unsigned long);
+       void (*ctor)(void *obj);
 } ecryptfs_cache_infos[] = {
        {
                .cache = &ecryptfs_auth_tok_list_item_cache,
@@ -586,11 +609,6 @@ static struct ecryptfs_cache_info {
                .size = sizeof(struct ecryptfs_sb_info),
        },
        {
-               .cache = &ecryptfs_header_cache_0,
-               .name = "ecryptfs_headers_0",
-               .size = PAGE_CACHE_SIZE,
-       },
-       {
                .cache = &ecryptfs_header_cache_1,
                .name = "ecryptfs_headers_1",
                .size = PAGE_CACHE_SIZE,
@@ -606,11 +624,6 @@ static struct ecryptfs_cache_info {
                .size = PAGE_CACHE_SIZE,
        },
        {
-               .cache = &ecryptfs_lower_page_cache,
-               .name = "ecryptfs_lower_page_cache",
-               .size = PAGE_CACHE_SIZE,
-       },
-       {
                .cache = &ecryptfs_key_record_cache,
                .name = "ecryptfs_key_record_cache",
                .size = sizeof(struct ecryptfs_key_record),
@@ -630,6 +643,11 @@ static struct ecryptfs_cache_info {
                .name = "ecryptfs_key_tfm_cache",
                .size = sizeof(struct ecryptfs_key_tfm),
        },
+       {
+               .cache = &ecryptfs_open_req_cache,
+               .name = "ecryptfs_open_req_cache",
+               .size = sizeof(struct ecryptfs_open_req),
+       },
 };
 
 static void ecryptfs_free_kmem_caches(void)
@@ -671,127 +689,40 @@ static int ecryptfs_init_kmem_caches(void)
        return 0;
 }
 
-struct ecryptfs_obj {
-       char *name;
-       struct list_head slot_list;
-       struct kobject kobj;
-};
+static struct kobject *ecryptfs_kobj;
 
-struct ecryptfs_attribute {
-       struct attribute attr;
-       ssize_t(*show) (struct ecryptfs_obj *, char *);
-       ssize_t(*store) (struct ecryptfs_obj *, const char *, size_t);
-};
-
-static ssize_t
-ecryptfs_attr_store(struct kobject *kobj,
-                   struct attribute *attr, const char *buf, size_t len)
-{
-       struct ecryptfs_obj *obj = container_of(kobj, struct ecryptfs_obj,
-                                               kobj);
-       struct ecryptfs_attribute *attribute =
-               container_of(attr, struct ecryptfs_attribute, attr);
-
-       return (attribute->store ? attribute->store(obj, buf, len) : 0);
-}
-
-static ssize_t
-ecryptfs_attr_show(struct kobject *kobj, struct attribute *attr, char *buf)
+static ssize_t version_show(struct kobject *kobj,
+                           struct kobj_attribute *attr, char *buff)
 {
-       struct ecryptfs_obj *obj = container_of(kobj, struct ecryptfs_obj,
-                                               kobj);
-       struct ecryptfs_attribute *attribute =
-               container_of(attr, struct ecryptfs_attribute, attr);
-
-       return (attribute->show ? attribute->show(obj, buf) : 0);
+       return snprintf(buff, PAGE_SIZE, "%d\n", ECRYPTFS_VERSIONING_MASK);
 }
 
-static struct sysfs_ops ecryptfs_sysfs_ops = {
-       .show = ecryptfs_attr_show,
-       .store = ecryptfs_attr_store
-};
+static struct kobj_attribute version_attr = __ATTR_RO(version);
 
-static struct kobj_type ecryptfs_ktype = {
-       .sysfs_ops = &ecryptfs_sysfs_ops
+static struct attribute *attributes[] = {
+       &version_attr.attr,
+       NULL,
 };
 
-static decl_subsys(ecryptfs, &ecryptfs_ktype, NULL);
-
-static ssize_t version_show(struct ecryptfs_obj *obj, char *buff)
-{
-       return snprintf(buff, PAGE_SIZE, "%d\n", ECRYPTFS_VERSIONING_MASK);
-}
-
-static struct ecryptfs_attribute sysfs_attr_version = __ATTR_RO(version);
-
-static struct ecryptfs_version_str_map_elem {
-       u32 flag;
-       char *str;
-} ecryptfs_version_str_map[] = {
-       {ECRYPTFS_VERSIONING_PASSPHRASE, "passphrase"},
-       {ECRYPTFS_VERSIONING_PUBKEY, "pubkey"},
-       {ECRYPTFS_VERSIONING_PLAINTEXT_PASSTHROUGH, "plaintext passthrough"},
-       {ECRYPTFS_VERSIONING_POLICY, "policy"},
-       {ECRYPTFS_VERSIONING_XATTR, "metadata in extended attribute"},
-       {ECRYPTFS_VERSIONING_MULTKEY, "multiple keys per file"}
+static struct attribute_group attr_group = {
+       .attrs = attributes,
 };
 
-static ssize_t version_str_show(struct ecryptfs_obj *obj, char *buff)
-{
-       int i;
-       int remaining = PAGE_SIZE;
-       int total_written = 0;
-
-       buff[0] = '\0';
-       for (i = 0; i < ARRAY_SIZE(ecryptfs_version_str_map); i++) {
-               int entry_size;
-
-               if (!(ECRYPTFS_VERSIONING_MASK
-                     & ecryptfs_version_str_map[i].flag))
-                       continue;
-               entry_size = strlen(ecryptfs_version_str_map[i].str);
-               if ((entry_size + 2) > remaining)
-                       goto out;
-               memcpy(buff, ecryptfs_version_str_map[i].str, entry_size);
-               buff[entry_size++] = '\n';
-               buff[entry_size] = '\0';
-               buff += entry_size;
-               total_written += entry_size;
-               remaining -= entry_size;
-       }
-out:
-       return total_written;
-}
-
-static struct ecryptfs_attribute sysfs_attr_version_str = __ATTR_RO(version_str);
-
 static int do_sysfs_registration(void)
 {
        int rc;
 
-       rc = subsystem_register(&ecryptfs_subsys);
-       if (rc) {
-               printk(KERN_ERR
-                      "Unable to register ecryptfs sysfs subsystem\n");
-               goto out;
-       }
-       rc = sysfs_create_file(&ecryptfs_subsys.kobj,
-                              &sysfs_attr_version.attr);
-       if (rc) {
-               printk(KERN_ERR
-                      "Unable to create ecryptfs version attribute\n");
-               subsystem_unregister(&ecryptfs_subsys);
+       ecryptfs_kobj = kobject_create_and_add("ecryptfs", fs_kobj);
+       if (!ecryptfs_kobj) {
+               printk(KERN_ERR "Unable to create ecryptfs kset\n");
+               rc = -ENOMEM;
                goto out;
        }
-       rc = sysfs_create_file(&ecryptfs_subsys.kobj,
-                              &sysfs_attr_version_str.attr);
+       rc = sysfs_create_group(ecryptfs_kobj, &attr_group);
        if (rc) {
                printk(KERN_ERR
-                      "Unable to create ecryptfs version_str attribute\n");
-               sysfs_remove_file(&ecryptfs_subsys.kobj,
-                                 &sysfs_attr_version.attr);
-               subsystem_unregister(&ecryptfs_subsys);
-               goto out;
+                      "Unable to create ecryptfs version attributes\n");
+               kobject_put(ecryptfs_kobj);
        }
 out:
        return rc;
@@ -799,11 +730,8 @@ out:
 
 static void do_sysfs_unregistration(void)
 {
-       sysfs_remove_file(&ecryptfs_subsys.kobj,
-                         &sysfs_attr_version.attr);
-       sysfs_remove_file(&ecryptfs_subsys.kobj,
-                         &sysfs_attr_version_str.attr);
-       subsystem_unregister(&ecryptfs_subsys);
+       sysfs_remove_group(ecryptfs_kobj, &attr_group);
+       kobject_put(ecryptfs_kobj);
 }
 
 static int __init ecryptfs_init(void)
@@ -831,27 +759,39 @@ static int __init ecryptfs_init(void)
                printk(KERN_ERR "Failed to register filesystem\n");
                goto out_free_kmem_caches;
        }
-       kobj_set_kset_s(&ecryptfs_subsys, fs_subsys);
        rc = do_sysfs_registration();
        if (rc) {
                printk(KERN_ERR "sysfs registration failed\n");
                goto out_unregister_filesystem;
        }
-       rc = ecryptfs_init_messaging(ecryptfs_transport);
+       rc = ecryptfs_init_kthread();
        if (rc) {
-               ecryptfs_printk(KERN_ERR, "Failure occured while attempting to "
-                               "initialize the eCryptfs netlink socket\n");
+               printk(KERN_ERR "%s: kthread initialization failed; "
+                      "rc = [%d]\n", __func__, rc);
                goto out_do_sysfs_unregistration;
        }
+       rc = ecryptfs_init_messaging();
+       if (rc) {
+               printk(KERN_ERR "Failure occured while attempting to "
+                               "initialize the communications channel to "
+                               "ecryptfsd\n");
+               goto out_destroy_kthread;
+       }
        rc = ecryptfs_init_crypto();
        if (rc) {
                printk(KERN_ERR "Failure whilst attempting to init crypto; "
                       "rc = [%d]\n", rc);
                goto out_release_messaging;
        }
+       if (ecryptfs_verbosity > 0)
+               printk(KERN_CRIT "eCryptfs verbosity set to %d. Secret values "
+                       "will be written to the syslog!\n", ecryptfs_verbosity);
+
        goto out;
 out_release_messaging:
-       ecryptfs_release_messaging(ecryptfs_transport);
+       ecryptfs_release_messaging();
+out_destroy_kthread:
+       ecryptfs_destroy_kthread();
 out_do_sysfs_unregistration:
        do_sysfs_unregistration();
 out_unregister_filesystem:
@@ -870,7 +810,8 @@ static void __exit ecryptfs_exit(void)
        if (rc)
                printk(KERN_ERR "Failure whilst attempting to destroy crypto; "
                       "rc = [%d]\n", rc);
-       ecryptfs_release_messaging(ecryptfs_transport);
+       ecryptfs_release_messaging();
+       ecryptfs_destroy_kthread();
        do_sysfs_unregistration();
        unregister_filesystem(&ecryptfs_fs_type);
        ecryptfs_free_kmem_caches();