1 files changed, 81 insertions, 85 deletions

diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c
index 760983d0f25e..cbd4e18adb20 100644
--- a/fs/ecryptfs/main.c
+++ b/fs/ecryptfs/main.c
@@ -281,7 +281,7 @@ static void ecryptfs_init_mount_crypt_stat(
  *
  * Returns zero on success; non-zero on error
  */
-static int ecryptfs_parse_options(struct super_block *sb, char *options)
+static int ecryptfs_parse_options(struct ecryptfs_sb_info *sbi, char *options)
 {
         char *p;
         int rc = 0;
@@ -293,7 +293,7 @@ static int ecryptfs_parse_options(struct super_block *sb, char *options)
         int fn_cipher_key_bytes;
         int fn_cipher_key_bytes_set = 0;
         struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
-                &ecryptfs_superblock_to_private(sb)->mount_crypt_stat;
+                &sbi->mount_crypt_stat;
         substring_t args[MAX_OPT_ARGS];
         int token;
         char *sig_src;
@@ -483,68 +483,7 @@ out:
 }
 
 struct kmem_cache *ecryptfs_sb_info_cache;
-
-/**
- * ecryptfs_fill_super
- * @sb: The ecryptfs super block
- * @raw_data: The options passed to mount
- * @silent: Not used but required by function prototype
- *
- * Sets up what we can of the sb, rest is done in ecryptfs_read_super
- *
- * Returns zero on success; non-zero otherwise
- */
-static int
-ecryptfs_fill_super(struct super_block *sb, void *raw_data, int silent)
-{
-        struct ecryptfs_sb_info *esi;
-        int rc = 0;
-
-        /* Released in ecryptfs_put_super() */
-        ecryptfs_set_superblock_private(sb,
-                                        kmem_cache_zalloc(ecryptfs_sb_info_cache,
-                                                         GFP_KERNEL));
-        esi = ecryptfs_superblock_to_private(sb);
-        if (!esi) {
-                ecryptfs_printk(KERN_WARNING, "Out of memory\n");
-                rc = -ENOMEM;
-                goto out;
-        }
-
-        rc = bdi_setup_and_register(&esi->bdi, "ecryptfs", BDI_CAP_MAP_COPY);
-        if (rc)
-                goto out;
-
-        sb->s_bdi = &esi->bdi;
-        sb->s_op = &ecryptfs_sops;
-        /* Released through deactivate_super(sb) from get_sb_nodev */
-        sb->s_root = d_alloc(NULL, &(const struct qstr) {
-                             .hash = 0,.name = "/",.len = 1});
-        if (!sb->s_root) {
-                ecryptfs_printk(KERN_ERR, "d_alloc failed\n");
-                rc = -ENOMEM;
-                goto out;
-        }
-        sb->s_root->d_op = &ecryptfs_dops;
-        sb->s_root->d_sb = sb;
-        sb->s_root->d_parent = sb->s_root;
-        /* Released in d_release when dput(sb->s_root) is called */
-        /* through deactivate_super(sb) from get_sb_nodev() */
-        ecryptfs_set_dentry_private(sb->s_root,
-                                    kmem_cache_zalloc(ecryptfs_dentry_info_cache,
-                                                     GFP_KERNEL));
-        if (!ecryptfs_dentry_to_private(sb->s_root)) {
-                ecryptfs_printk(KERN_ERR,
-                                "dentry_info_cache alloc failed\n");
-                rc = -ENOMEM;
-                goto out;
-        }
-        rc = 0;
-out:
-        /* Should be able to rely on deactivate_super called from
-         * get_sb_nodev */
-        return rc;
-}
+static struct file_system_type ecryptfs_fs_type;
 
 /**
  * ecryptfs_read_super
@@ -565,6 +504,13 @@ static int ecryptfs_read_super(struct super_block *sb, const char *dev_name)
                 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;
@@ -588,11 +534,8 @@ out:
  * @dev_name: The path to mount over
  * @raw_data: The options passed into the kernel
  *
- * The whole ecryptfs_get_sb process is broken into 4 functions:
+ * The whole ecryptfs_get_sb process is broken into 3 functions:
  * ecryptfs_parse_options(): handle options passed to ecryptfs, if any
- * ecryptfs_fill_super(): used by get_sb_nodev, fills out the super_block
- *                        with as much information as it can before needing
- *                        the lower filesystem.
  * 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)
@@ -601,30 +544,78 @@ static int ecryptfs_get_sb(struct file_system_type *fs_type, int flags,
                         const char *dev_name, void *raw_data,
                         struct vfsmount *mnt)
 {
+        struct super_block *s;
+        struct ecryptfs_sb_info *sbi;
+        struct ecryptfs_dentry_info *root_info;
+        const char *err = "Getting sb failed";
         int rc;
-        struct super_block *sb;
 
-        rc = get_sb_nodev(fs_type, flags, raw_data, ecryptfs_fill_super, mnt);
-        if (rc < 0) {
-                printk(KERN_ERR "Getting sb failed; rc = [%d]\n", rc);
+        sbi = kmem_cache_zalloc(ecryptfs_sb_info_cache, GFP_KERNEL);
+        if (!sbi) {
+                rc = -ENOMEM;
                 goto out;
         }
-        sb = mnt->mnt_sb;
-        rc = ecryptfs_parse_options(sb, raw_data);
+
+        rc = ecryptfs_parse_options(sbi, raw_data);
         if (rc) {
-                printk(KERN_ERR "Error parsing options; rc = [%d]\n", rc);
-                goto out_abort;
+                err = "Error parsing options";
+                goto out;
+        }
+
+        s = sget(fs_type, NULL, set_anon_super, NULL);
+        if (IS_ERR(s)) {
+                rc = PTR_ERR(s);
+                goto out;
         }
-        rc = ecryptfs_read_super(sb, dev_name);
+
+        s->s_flags = flags;
+        rc = bdi_setup_and_register(&sbi->bdi, "ecryptfs", BDI_CAP_MAP_COPY);
         if (rc) {
-                printk(KERN_ERR "Reading sb failed; rc = [%d]\n", rc);
-                goto out_abort;
+                deactivate_locked_super(s);
+                goto out;
         }
-        goto out;
-out_abort:
-        dput(sb->s_root); /* aka mnt->mnt_root, as set by get_sb_nodev() */
-        deactivate_locked_super(sb);
+
+        ecryptfs_set_superblock_private(s, sbi);
+        s->s_bdi = &sbi->bdi;
+
+        /* ->kill_sb() will take care of sbi after that point */
+        sbi = NULL;
+        s->s_op = &ecryptfs_sops;
+
+        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;
+        }
+        s->s_root->d_op = &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;
+        }
+        /* ->kill_sb() will take care of root_info */
+        ecryptfs_set_dentry_private(s->s_root, root_info);
+        s->s_flags |= MS_ACTIVE;
+        rc = ecryptfs_read_super(s, dev_name);
+        if (rc) {
+                deactivate_locked_super(s);
+                err = "Reading sb failed";
+                goto out;
+        }
+        simple_set_mnt(mnt, s);
+        return 0;
+
 out:
+        if (sbi) {
+                ecryptfs_destroy_mount_crypt_stat(&sbi->mount_crypt_stat);
+                kmem_cache_free(ecryptfs_sb_info_cache, sbi);
+        }
+        printk(KERN_ERR "%s; rc = [%d]\n", err, rc);
         return rc;
 }
 
@@ -633,11 +624,16 @@ out:
  * @sb: The ecryptfs super block
  *
  * Used to bring the superblock down and free the private data.
- * Private data is free'd in ecryptfs_put_super()
  */
 static void ecryptfs_kill_block_super(struct super_block *sb)
 {
-        generic_shutdown_super(sb);
+        struct ecryptfs_sb_info *sb_info = ecryptfs_superblock_to_private(sb);
+        kill_anon_super(sb);
+        if (!sb_info)
+                return;
+        ecryptfs_destroy_mount_crypt_stat(&sb_info->mount_crypt_stat);
+        bdi_destroy(&sb_info->bdi);
+        kmem_cache_free(ecryptfs_sb_info_cache, sb_info);
 }
 
 static struct file_system_type ecryptfs_fs_type = {