Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ecryptfs/ecryptfs-2.6

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ecryptfs/ecryptfs-2.6:
  eCryptfs: Remove ecryptfs_header_cache_2
  eCryptfs: Cleanup and optimize ecryptfs_lookup_interpose()
  eCryptfs: Return useful code from contains_ecryptfs_marker
  eCryptfs: Fix new inode race condition
  eCryptfs: Cleanup inode initialization code
  eCryptfs: Consolidate inode functions into inode.c

1 files changed, 173 insertions, 108 deletions

diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index 94ab3c06317a..7349ade17de6 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -51,6 +51,97 @@ static void unlock_dir(struct dentry *dir)
         dput(dir);
 }
 
+static int ecryptfs_inode_test(struct inode *inode, void *lower_inode)
+{
+        if (ecryptfs_inode_to_lower(inode) == (struct inode *)lower_inode)
+                return 1;
+        return 0;
+}
+
+static int ecryptfs_inode_set(struct inode *inode, void *opaque)
+{
+        struct inode *lower_inode = opaque;
+
+        ecryptfs_set_inode_lower(inode, lower_inode);
+        fsstack_copy_attr_all(inode, lower_inode);
+        /* i_size will be overwritten for encrypted regular files */
+        fsstack_copy_inode_size(inode, lower_inode);
+        inode->i_ino = lower_inode->i_ino;
+        inode->i_version++;
+        inode->i_mapping->a_ops = &ecryptfs_aops;
+
+        if (S_ISLNK(inode->i_mode))
+                inode->i_op = &ecryptfs_symlink_iops;
+        else if (S_ISDIR(inode->i_mode))
+                inode->i_op = &ecryptfs_dir_iops;
+        else
+                inode->i_op = &ecryptfs_main_iops;
+
+        if (S_ISDIR(inode->i_mode))
+                inode->i_fop = &ecryptfs_dir_fops;
+        else if (special_file(inode->i_mode))
+                init_special_inode(inode, inode->i_mode, inode->i_rdev);
+        else
+                inode->i_fop = &ecryptfs_main_fops;
+
+        return 0;
+}
+
+static struct inode *__ecryptfs_get_inode(struct inode *lower_inode,
+                                          struct super_block *sb)
+{
+        struct inode *inode;
+
+        if (lower_inode->i_sb != ecryptfs_superblock_to_lower(sb))
+                return ERR_PTR(-EXDEV);
+        if (!igrab(lower_inode))
+                return ERR_PTR(-ESTALE);
+        inode = iget5_locked(sb, (unsigned long)lower_inode,
+                             ecryptfs_inode_test, ecryptfs_inode_set,
+                             lower_inode);
+        if (!inode) {
+                iput(lower_inode);
+                return ERR_PTR(-EACCES);
+        }
+        if (!(inode->i_state & I_NEW))
+                iput(lower_inode);
+
+        return inode;
+}
+
+struct inode *ecryptfs_get_inode(struct inode *lower_inode,
+                                 struct super_block *sb)
+{
+        struct inode *inode = __ecryptfs_get_inode(lower_inode, sb);
+
+        if (!IS_ERR(inode) && (inode->i_state & I_NEW))
+                unlock_new_inode(inode);
+
+        return inode;
+}
+
+/**
+ * ecryptfs_interpose
+ * @lower_dentry: Existing dentry in the lower filesystem
+ * @dentry: ecryptfs' dentry
+ * @sb: ecryptfs's super_block
+ *
+ * Interposes upper and lower dentries.
+ *
+ * Returns zero on success; non-zero otherwise
+ */
+static int ecryptfs_interpose(struct dentry *lower_dentry,
+                              struct dentry *dentry, struct super_block *sb)
+{
+        struct inode *inode = ecryptfs_get_inode(lower_dentry->d_inode, sb);
+
+        if (IS_ERR(inode))
+                return PTR_ERR(inode);
+        d_instantiate(dentry, inode);
+
+        return 0;
+}
+
 /**
  * ecryptfs_create_underlying_file
  * @lower_dir_inode: inode of the parent in the lower fs of the new file
@@ -129,7 +220,7 @@ ecryptfs_do_create(struct inode *directory_inode,
                 goto out_lock;
         }
         rc = ecryptfs_interpose(lower_dentry, ecryptfs_dentry,
-                                directory_inode->i_sb, 0);
+                                directory_inode->i_sb);
         if (rc) {
                 ecryptfs_printk(KERN_ERR, "Failure in ecryptfs_interpose\n");
                 goto out_lock;
@@ -168,7 +259,8 @@ static int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry)
                                 "context; rc = [%d]\n", rc);
                 goto out;
         }
-        rc = ecryptfs_get_lower_file(ecryptfs_dentry);
+        rc = ecryptfs_get_lower_file(ecryptfs_dentry,
+                                     ecryptfs_dentry->d_inode);
         if (rc) {
                 printk(KERN_ERR "%s: Error attempting to initialize "
                         "the lower file for the dentry with name "
@@ -215,102 +307,90 @@ out:
         return rc;
 }
 
+static int ecryptfs_i_size_read(struct dentry *dentry, struct inode *inode)
+{
+        struct ecryptfs_crypt_stat *crypt_stat;
+        int rc;
+
+        rc = ecryptfs_get_lower_file(dentry, inode);
+        if (rc) {
+                printk(KERN_ERR "%s: Error attempting to initialize "
+                        "the lower file for the dentry with name "
+                        "[%s]; rc = [%d]\n", __func__,
+                        dentry->d_name.name, rc);
+                return rc;
+        }
+
+        crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
+        /* TODO: lock for crypt_stat comparison */
+        if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED))
+                ecryptfs_set_default_sizes(crypt_stat);
+
+        rc = ecryptfs_read_and_validate_header_region(inode);
+        ecryptfs_put_lower_file(inode);
+        if (rc) {
+                rc = ecryptfs_read_and_validate_xattr_region(dentry, inode);
+                if (!rc)
+                        crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;
+        }
+
+        /* Must return 0 to allow non-eCryptfs files to be looked up, too */
+        return 0;
+}
+
 /**
- * ecryptfs_lookup_and_interpose_lower - Perform a lookup
+ * ecryptfs_lookup_interpose - Dentry interposition for a lookup
  */
-int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry,
-                                        struct dentry *lower_dentry,
-                                        struct inode *ecryptfs_dir_inode)
+static int ecryptfs_lookup_interpose(struct dentry *dentry,
+                                     struct dentry *lower_dentry,
+                                     struct inode *dir_inode)
 {
-        struct dentry *lower_dir_dentry;
+        struct inode *inode, *lower_inode = lower_dentry->d_inode;
+        struct ecryptfs_dentry_info *dentry_info;
         struct vfsmount *lower_mnt;
-        struct inode *lower_inode;
-        struct ecryptfs_crypt_stat *crypt_stat;
-        char *page_virt = NULL;
-        int put_lower = 0, rc = 0;
-
-        lower_dir_dentry = lower_dentry->d_parent;
-        lower_mnt = mntget(ecryptfs_dentry_to_lower_mnt(
-                                   ecryptfs_dentry->d_parent));
-        lower_inode = lower_dentry->d_inode;
-        fsstack_copy_attr_atime(ecryptfs_dir_inode, lower_dir_dentry->d_inode);
+        int rc = 0;
+
+        lower_mnt = mntget(ecryptfs_dentry_to_lower_mnt(dentry->d_parent));
+        fsstack_copy_attr_atime(dir_inode, lower_dentry->d_parent->d_inode);
         BUG_ON(!lower_dentry->d_count);
-        ecryptfs_set_dentry_private(ecryptfs_dentry,
-                                    kmem_cache_alloc(ecryptfs_dentry_info_cache,
-                                                     GFP_KERNEL));
-        if (!ecryptfs_dentry_to_private(ecryptfs_dentry)) {
-                rc = -ENOMEM;
+
+        dentry_info = kmem_cache_alloc(ecryptfs_dentry_info_cache, GFP_KERNEL);
+        ecryptfs_set_dentry_private(dentry, dentry_info);
+        if (!dentry_info) {
                 printk(KERN_ERR "%s: Out of memory whilst attempting "
                        "to allocate ecryptfs_dentry_info struct\n",
                         __func__);
-                goto out_put;
+                dput(lower_dentry);
+                mntput(lower_mnt);
+                d_drop(dentry);
+                return -ENOMEM;
         }
-        ecryptfs_set_dentry_lower(ecryptfs_dentry, lower_dentry);
-        ecryptfs_set_dentry_lower_mnt(ecryptfs_dentry, lower_mnt);
+        ecryptfs_set_dentry_lower(dentry, lower_dentry);
+        ecryptfs_set_dentry_lower_mnt(dentry, lower_mnt);
+
         if (!lower_dentry->d_inode) {
                 /* We want to add because we couldn't find in lower */
-                d_add(ecryptfs_dentry, NULL);
-                goto out;
+                d_add(dentry, NULL);
+                return 0;
         }
-        rc = ecryptfs_interpose(lower_dentry, ecryptfs_dentry,
-                                ecryptfs_dir_inode->i_sb,
-                                ECRYPTFS_INTERPOSE_FLAG_D_ADD);
-        if (rc) {
-                printk(KERN_ERR "%s: Error interposing; rc = [%d]\n",
-                       __func__, rc);
-                goto out;
+        inode = __ecryptfs_get_inode(lower_inode, dir_inode->i_sb);
+        if (IS_ERR(inode)) {
+                printk(KERN_ERR "%s: Error interposing; rc = [%ld]\n",
+                       __func__, PTR_ERR(inode));
+                return PTR_ERR(inode);
         }
-        if (S_ISDIR(lower_inode->i_mode))
-                goto out;
-        if (S_ISLNK(lower_inode->i_mode))
-                goto out;
-        if (special_file(lower_inode->i_mode))
-                goto out;
-        /* Released in this function */
-        page_virt = kmem_cache_zalloc(ecryptfs_header_cache_2, GFP_USER);
-        if (!page_virt) {
-                printk(KERN_ERR "%s: Cannot kmem_cache_zalloc() a page\n",
-                       __func__);
-                rc = -ENOMEM;
-                goto out;
-        }
-        rc = ecryptfs_get_lower_file(ecryptfs_dentry);
-        if (rc) {
-                printk(KERN_ERR "%s: Error attempting to initialize "
-                        "the lower file for the dentry with name "
-                        "[%s]; rc = [%d]\n", __func__,
-                        ecryptfs_dentry->d_name.name, rc);
-                goto out_free_kmem;
-        }
-        put_lower = 1;
-        crypt_stat = &ecryptfs_inode_to_private(
-                                        ecryptfs_dentry->d_inode)->crypt_stat;
-        /* TODO: lock for crypt_stat comparison */
-        if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED))
-                        ecryptfs_set_default_sizes(crypt_stat);
-        rc = ecryptfs_read_and_validate_header_region(page_virt,
-                                                      ecryptfs_dentry->d_inode);
-        if (rc) {
-                memset(page_virt, 0, PAGE_CACHE_SIZE);
-                rc = ecryptfs_read_and_validate_xattr_region(page_virt,
-                                                             ecryptfs_dentry);
+        if (S_ISREG(inode->i_mode)) {
+                rc = ecryptfs_i_size_read(dentry, inode);
                 if (rc) {
-                        rc = 0;
-                        goto out_free_kmem;
+                        make_bad_inode(inode);
+                        return rc;
                 }
-                crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;
         }
-        ecryptfs_i_size_init(page_virt, ecryptfs_dentry->d_inode);
-out_free_kmem:
-        kmem_cache_free(ecryptfs_header_cache_2, page_virt);
-        goto out;
-out_put:
-        dput(lower_dentry);
-        mntput(lower_mnt);
-        d_drop(ecryptfs_dentry);
-out:
-        if (put_lower)
-                ecryptfs_put_lower_file(ecryptfs_dentry->d_inode);
+
+        if (inode->i_state & I_NEW)
+                unlock_new_inode(inode);
+        d_add(dentry, inode);
+
         return rc;
 }
 
@@ -353,12 +433,12 @@ static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
                 goto out_d_drop;
         }
         if (lower_dentry->d_inode)
-                goto lookup_and_interpose;
+                goto interpose;
         mount_crypt_stat = &ecryptfs_superblock_to_private(
                                 ecryptfs_dentry->d_sb)->mount_crypt_stat;
         if (!(mount_crypt_stat
             && (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)))
-                goto lookup_and_interpose;
+                goto interpose;
         dput(lower_dentry);
         rc = ecryptfs_encrypt_and_encode_filename(
                 &encrypted_and_encoded_name, &encrypted_and_encoded_name_size,
@@ -381,9 +461,9 @@ static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
                                 encrypted_and_encoded_name);
                 goto out_d_drop;
         }
-lookup_and_interpose:
-        rc = ecryptfs_lookup_and_interpose_lower(ecryptfs_dentry, lower_dentry,
-                                                 ecryptfs_dir_inode);
+interpose:
+        rc = ecryptfs_lookup_interpose(ecryptfs_dentry, lower_dentry,
+                                       ecryptfs_dir_inode);
         goto out;
 out_d_drop:
         d_drop(ecryptfs_dentry);
@@ -411,7 +491,7 @@ static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir,
                       lower_new_dentry);
         if (rc || !lower_new_dentry->d_inode)
                 goto out_lock;
-        rc = ecryptfs_interpose(lower_new_dentry, new_dentry, dir->i_sb, 0);
+        rc = ecryptfs_interpose(lower_new_dentry, new_dentry, dir->i_sb);
         if (rc)
                 goto out_lock;
         fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
@@ -478,7 +558,7 @@ static int ecryptfs_symlink(struct inode *dir, struct dentry *dentry,
         kfree(encoded_symname);
         if (rc || !lower_dentry->d_inode)
                 goto out_lock;
-        rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
+        rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
         if (rc)
                 goto out_lock;
         fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
@@ -502,7 +582,7 @@ static int ecryptfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
         rc = vfs_mkdir(lower_dir_dentry->d_inode, lower_dentry, mode);
         if (rc || !lower_dentry->d_inode)
                 goto out;
-        rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
+        rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
         if (rc)
                 goto out;
         fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
@@ -550,7 +630,7 @@ ecryptfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
         rc = vfs_mknod(lower_dir_dentry->d_inode, lower_dentry, mode, dev);
         if (rc || !lower_dentry->d_inode)
                 goto out;
-        rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
+        rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
         if (rc)
                 goto out;
         fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
@@ -750,7 +830,7 @@ static int truncate_upper(struct dentry *dentry, struct iattr *ia,
                 lower_ia->ia_valid &= ~ATTR_SIZE;
                 return 0;
         }
-        rc = ecryptfs_get_lower_file(dentry);
+        rc = ecryptfs_get_lower_file(dentry, inode);
         if (rc)
                 return rc;
         crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
@@ -906,7 +986,7 @@ static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
 
                 mount_crypt_stat = &ecryptfs_superblock_to_private(
                         dentry->d_sb)->mount_crypt_stat;
-                rc = ecryptfs_get_lower_file(dentry);
+                rc = ecryptfs_get_lower_file(dentry, inode);
                 if (rc) {
                         mutex_unlock(&crypt_stat->cs_mutex);
                         goto out;
@@ -1079,21 +1159,6 @@ out:
         return rc;
 }
 
-int ecryptfs_inode_test(struct inode *inode, void *candidate_lower_inode)
-{
-        if ((ecryptfs_inode_to_lower(inode)
-             == (struct inode *)candidate_lower_inode))
-                return 1;
-        else
-                return 0;
-}
-
-int ecryptfs_inode_set(struct inode *inode, void *lower_inode)
-{
-        ecryptfs_init_inode(inode, (struct inode *)lower_inode);
-        return 0;
-}
-
 const struct inode_operations ecryptfs_symlink_iops = {
         .readlink = ecryptfs_readlink,
         .follow_link = ecryptfs_follow_link,