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: Turn lower lookup error messages into debug messages eCryptfs: Copy lower directory inode times and size on link ecryptfs: fix use with tmpfs by removing d_drop from ecryptfs_destroy_inode ecryptfs: fix error code for missing xattrs in lower fs eCryptfs: Decrypt symlink target for stat size eCryptfs: Strip metadata in xattr flag in encrypted view eCryptfs: Clear buffer before reading in metadata xattr eCryptfs: Rename ecryptfs_crypt_stat.num_header_bytes_at_front eCryptfs: Fix metadata in xattr feature regression
2010-04-19 14:20:32 -07:00 · 2010-04-19 14:20:32 -07:00 · 9b030e2006
commit 9b030e2006
parent 76e506a754 9f37622f89
5 changed files with 118 additions and 100 deletions
--- a/fs/ecryptfs/crypto.c
+++ b/fs/ecryptfs/crypto.c
@ -382,8 +382,8 @@ static int encrypt_scatterlist(struct ecryptfs_crypt_stat *crypt_stat,
 static void ecryptfs_lower_offset_for_extent(loff_t *offset, loff_t extent_num,
 					     struct ecryptfs_crypt_stat *crypt_stat)
 {
-	(*offset) = (crypt_stat->num_header_bytes_at_front
-		     + (crypt_stat->extent_size * extent_num));
+	(*offset) = ecryptfs_lower_header_size(crypt_stat)
+		    + (crypt_stat->extent_size * extent_num);
 }

 /**
@ -835,13 +835,13 @@ void ecryptfs_set_default_sizes(struct ecryptfs_crypt_stat *crypt_stat)
 	set_extent_mask_and_shift(crypt_stat);
 	crypt_stat->iv_bytes = ECRYPTFS_DEFAULT_IV_BYTES;
 	if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR)
-		crypt_stat->num_header_bytes_at_front = 0;
+		crypt_stat->metadata_size = ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE;
 	else {
 		if (PAGE_CACHE_SIZE <= ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE)
-			crypt_stat->num_header_bytes_at_front =
+			crypt_stat->metadata_size =
 				ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE;
 		else
-			crypt_stat->num_header_bytes_at_front =	PAGE_CACHE_SIZE;
+			crypt_stat->metadata_size = PAGE_CACHE_SIZE;
 	}
 }

@ -1108,9 +1108,9 @@ static void write_ecryptfs_marker(char *page_virt, size_t *written)
 	(*written) = MAGIC_ECRYPTFS_MARKER_SIZE_BYTES;
 }

-static void
-write_ecryptfs_flags(char *page_virt, struct ecryptfs_crypt_stat *crypt_stat,
-		     size_t *written)
+void ecryptfs_write_crypt_stat_flags(char *page_virt,
+				     struct ecryptfs_crypt_stat *crypt_stat,
+				     size_t *written)
 {
 	u32 flags = 0;
 	int i;
@ -1238,8 +1238,7 @@ ecryptfs_write_header_metadata(char *virt,

 	header_extent_size = (u32)crypt_stat->extent_size;
 	num_header_extents_at_front =
-		(u16)(crypt_stat->num_header_bytes_at_front
-		      / crypt_stat->extent_size);
+		(u16)(crypt_stat->metadata_size / crypt_stat->extent_size);
 	put_unaligned_be32(header_extent_size, virt);
 	virt += 4;
 	put_unaligned_be16(num_header_extents_at_front, virt);
@ -1292,7 +1291,8 @@ static int ecryptfs_write_headers_virt(char *page_virt, size_t max,
 	offset = ECRYPTFS_FILE_SIZE_BYTES;
 	write_ecryptfs_marker((page_virt + offset), &written);
 	offset += written;
-	write_ecryptfs_flags((page_virt + offset), crypt_stat, &written);
+	ecryptfs_write_crypt_stat_flags((page_virt + offset), crypt_stat,
+					&written);
 	offset += written;
 	ecryptfs_write_header_metadata((page_virt + offset), crypt_stat,
 				       &written);
@ -1382,7 +1382,7 @@ int ecryptfs_write_metadata(struct dentry *ecryptfs_dentry)
 		rc = -EINVAL;
 		goto out;
 	}
-	virt_len = crypt_stat->num_header_bytes_at_front;
+	virt_len = crypt_stat->metadata_size;
 	order = get_order(virt_len);
 	/* Released in this function */
 	virt = (char *)ecryptfs_get_zeroed_pages(GFP_KERNEL, order);
@ -1428,16 +1428,15 @@ static int parse_header_metadata(struct ecryptfs_crypt_stat *crypt_stat,
 	header_extent_size = get_unaligned_be32(virt);
 	virt += sizeof(__be32);
 	num_header_extents_at_front = get_unaligned_be16(virt);
-	crypt_stat->num_header_bytes_at_front =
-		(((size_t)num_header_extents_at_front
-		  * (size_t)header_extent_size));
+	crypt_stat->metadata_size = (((size_t)num_header_extents_at_front
+				     * (size_t)header_extent_size));
 	(*bytes_read) = (sizeof(__be32) + sizeof(__be16));
 	if ((validate_header_size == ECRYPTFS_VALIDATE_HEADER_SIZE)
-	    && (crypt_stat->num_header_bytes_at_front
+	    && (crypt_stat->metadata_size
 		< ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE)) {
 		rc = -EINVAL;
 		printk(KERN_WARNING "Invalid header size: [%zd]\n",
-		       crypt_stat->num_header_bytes_at_front);
+		       crypt_stat->metadata_size);
 	}
 	return rc;
 }
@ -1452,8 +1451,7 @@ static int parse_header_metadata(struct ecryptfs_crypt_stat *crypt_stat,
 */
 static void set_default_header_data(struct ecryptfs_crypt_stat *crypt_stat)
 {
-	crypt_stat->num_header_bytes_at_front =
-		ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE;
+	crypt_stat->metadata_size = ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE;
 }

 /**
@ -1607,6 +1605,7 @@ int ecryptfs_read_metadata(struct dentry *ecryptfs_dentry)
 						ecryptfs_dentry,
 						ECRYPTFS_VALIDATE_HEADER_SIZE);
 	if (rc) {
+		memset(page_virt, 0, PAGE_CACHE_SIZE);
 		rc = ecryptfs_read_xattr_region(page_virt, ecryptfs_inode);
 		if (rc) {
 			printk(KERN_DEBUG "Valid eCryptfs headers not found in "
--- a/fs/ecryptfs/ecryptfs_kernel.h
+++ b/fs/ecryptfs/ecryptfs_kernel.h
@ -273,7 +273,7 @@ struct ecryptfs_crypt_stat {
 	u32 flags;
 	unsigned int file_version;
 	size_t iv_bytes;
-	size_t num_header_bytes_at_front;
+	size_t metadata_size;
 	size_t extent_size; /* Data extent size; default is 4096 */
 	size_t key_size;
 	size_t extent_shift;
@ -464,6 +464,14 @@ struct ecryptfs_daemon {

 extern struct mutex ecryptfs_daemon_hash_mux;

+static inline size_t
+ecryptfs_lower_header_size(struct ecryptfs_crypt_stat *crypt_stat)
+{
+	if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR)
+		return 0;
+	return crypt_stat->metadata_size;
+}
+
 static inline struct ecryptfs_file_info *
 ecryptfs_file_to_private(struct file *file)
 {
@ -651,6 +659,9 @@ int ecryptfs_decrypt_page(struct page *page);
 int ecryptfs_write_metadata(struct dentry *ecryptfs_dentry);
 int ecryptfs_read_metadata(struct dentry *ecryptfs_dentry);
 int ecryptfs_new_file_context(struct dentry *ecryptfs_dentry);
+void ecryptfs_write_crypt_stat_flags(char *page_virt,
+				     struct ecryptfs_crypt_stat *crypt_stat,
+				     size_t *written);
 int ecryptfs_read_and_validate_header_region(char *data,
 					     struct inode *ecryptfs_inode);
 int ecryptfs_read_and_validate_xattr_region(char *page_virt,
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@ -324,6 +324,7 @@ int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry,
 	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 (rc) {
@ -336,7 +337,7 @@ int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry,
 		ecryptfs_dentry->d_sb)->mount_crypt_stat;
 	if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) {
 		if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR)
-			file_size = (crypt_stat->num_header_bytes_at_front
+			file_size = (crypt_stat->metadata_size
 				     + i_size_read(lower_dentry->d_inode));
 		else
 			file_size = i_size_read(lower_dentry->d_inode);
@ -388,9 +389,9 @@ static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
 	mutex_unlock(&lower_dir_dentry->d_inode->i_mutex);
 	if (IS_ERR(lower_dentry)) {
 		rc = PTR_ERR(lower_dentry);
-		printk(KERN_ERR "%s: lookup_one_len() returned [%d] on "
-		       "lower_dentry = [%s]\n", __func__, rc,
-		       ecryptfs_dentry->d_name.name);
+		ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
+				"[%d] on lower_dentry = [%s]\n", __func__, rc,
+				encrypted_and_encoded_name);
 		goto out_d_drop;
 	}
 	if (lower_dentry->d_inode)
@ -417,9 +418,9 @@ static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
 	mutex_unlock(&lower_dir_dentry->d_inode->i_mutex);
 	if (IS_ERR(lower_dentry)) {
 		rc = PTR_ERR(lower_dentry);
-		printk(KERN_ERR "%s: lookup_one_len() returned [%d] on "
-		       "lower_dentry = [%s]\n", __func__, rc,
-		       encrypted_and_encoded_name);
+		ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
+				"[%d] on lower_dentry = [%s]\n", __func__, rc,
+				encrypted_and_encoded_name);
 		goto out_d_drop;
 	}
 lookup_and_interpose:
@ -456,8 +457,8 @@ static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir,
 	rc = ecryptfs_interpose(lower_new_dentry, new_dentry, dir->i_sb, 0);
 	if (rc)
 		goto out_lock;
-	fsstack_copy_attr_times(dir, lower_new_dentry->d_inode);
-	fsstack_copy_inode_size(dir, lower_new_dentry->d_inode);
+	fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
+	fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
 	old_dentry->d_inode->i_nlink =
 		ecryptfs_inode_to_lower(old_dentry->d_inode)->i_nlink;
 	i_size_write(new_dentry->d_inode, file_size_save);
@ -648,38 +649,17 @@ ecryptfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 	return rc;
 }

-static int
-ecryptfs_readlink(struct dentry *dentry, char __user *buf, int bufsiz)
+static int ecryptfs_readlink_lower(struct dentry *dentry, char **buf,
+				   size_t *bufsiz)
 {
+	struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
 	char *lower_buf;
-	size_t lower_bufsiz;
-	struct dentry *lower_dentry;
-	struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
-	char *plaintext_name;
-	size_t plaintext_name_size;
+	size_t lower_bufsiz = PATH_MAX;
 	mm_segment_t old_fs;
 	int rc;

-	lower_dentry = ecryptfs_dentry_to_lower(dentry);
-	if (!lower_dentry->d_inode->i_op->readlink) {
-		rc = -EINVAL;
-		goto out;
-	}
-	mount_crypt_stat = &ecryptfs_superblock_to_private(
-						dentry->d_sb)->mount_crypt_stat;
-	/*
-	 * If the lower filename is encrypted, it will result in a significantly
-	 * longer name.  If needed, truncate the name after decode and decrypt.
-	 */
-	if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)
-		lower_bufsiz = PATH_MAX;
-	else
-		lower_bufsiz = bufsiz;
-	/* Released in this function */
 	lower_buf = kmalloc(lower_bufsiz, GFP_KERNEL);
-	if (lower_buf == NULL) {
-		printk(KERN_ERR "%s: Out of memory whilst attempting to "
-		       "kmalloc [%zd] bytes\n", __func__, lower_bufsiz);
+	if (!lower_buf) {
 		rc = -ENOMEM;
 		goto out;
 	}
@ -689,29 +669,31 @@ ecryptfs_readlink(struct dentry *dentry, char __user *buf, int bufsiz)
 						   (char __user *)lower_buf,
 						   lower_bufsiz);
 	set_fs(old_fs);
-	if (rc >= 0) {
-		rc = ecryptfs_decode_and_decrypt_filename(&plaintext_name,
-							  &plaintext_name_size,
-							  dentry, lower_buf,
-							  rc);
-		if (rc) {
-			printk(KERN_ERR "%s: Error attempting to decode and "
-			       "decrypt filename; rc = [%d]\n", __func__,
-				rc);
-			goto out_free_lower_buf;
-		}
-		/* Check for bufsiz <= 0 done in sys_readlinkat() */
-		rc = copy_to_user(buf, plaintext_name,
-				  min((size_t) bufsiz, plaintext_name_size));
-		if (rc)
-			rc = -EFAULT;
-		else
-			rc = plaintext_name_size;
-		kfree(plaintext_name);
-		fsstack_copy_attr_atime(dentry->d_inode, lower_dentry->d_inode);
-	}
-out_free_lower_buf:
+	if (rc < 0)
+		goto out;
+	lower_bufsiz = rc;
+	rc = ecryptfs_decode_and_decrypt_filename(buf, bufsiz, dentry,
+						  lower_buf, lower_bufsiz);
+out:
 	kfree(lower_buf);
+	return rc;
+}
+
+static int
+ecryptfs_readlink(struct dentry *dentry, char __user *buf, int bufsiz)
+{
+	char *kbuf;
+	size_t kbufsiz, copied;
+	int rc;
+
+	rc = ecryptfs_readlink_lower(dentry, &kbuf, &kbufsiz);
+	if (rc)
+		goto out;
+	copied = min_t(size_t, bufsiz, kbufsiz);
+	rc = copy_to_user(buf, kbuf, copied) ? -EFAULT : copied;
+	kfree(kbuf);
+	fsstack_copy_attr_atime(dentry->d_inode,
+				ecryptfs_dentry_to_lower(dentry)->d_inode);
 out:
 	return rc;
 }
@ -769,7 +751,7 @@ upper_size_to_lower_size(struct ecryptfs_crypt_stat *crypt_stat,
 {
 	loff_t lower_size;

-	lower_size = crypt_stat->num_header_bytes_at_front;
+	lower_size = ecryptfs_lower_header_size(crypt_stat);
 	if (upper_size != 0) {
 		loff_t num_extents;

@ -1016,6 +998,28 @@ static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
 	return rc;
 }

+int ecryptfs_getattr_link(struct vfsmount *mnt, struct dentry *dentry,
+			  struct kstat *stat)
+{
+	struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
+	int rc = 0;
+
+	mount_crypt_stat = &ecryptfs_superblock_to_private(
+						dentry->d_sb)->mount_crypt_stat;
+	generic_fillattr(dentry->d_inode, stat);
+	if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) {
+		char *target;
+		size_t targetsiz;
+
+		rc = ecryptfs_readlink_lower(dentry, &target, &targetsiz);
+		if (!rc) {
+			kfree(target);
+			stat->size = targetsiz;
+		}
+	}
+	return rc;
+}
+
 int ecryptfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
 		     struct kstat *stat)
 {
@ -1040,7 +1044,7 @@ ecryptfs_setxattr(struct dentry *dentry, const char *name, const void *value,

 	lower_dentry = ecryptfs_dentry_to_lower(dentry);
 	if (!lower_dentry->d_inode->i_op->setxattr) {
-		rc = -ENOSYS;
+		rc = -EOPNOTSUPP;
 		goto out;
 	}
 	mutex_lock(&lower_dentry->d_inode->i_mutex);
@ -1058,7 +1062,7 @@ ecryptfs_getxattr_lower(struct dentry *lower_dentry, const char *name,
 	int rc = 0;

 	if (!lower_dentry->d_inode->i_op->getxattr) {
-		rc = -ENOSYS;
+		rc = -EOPNOTSUPP;
 		goto out;
 	}
 	mutex_lock(&lower_dentry->d_inode->i_mutex);
@ -1085,7 +1089,7 @@ ecryptfs_listxattr(struct dentry *dentry, char *list, size_t size)

 	lower_dentry = ecryptfs_dentry_to_lower(dentry);
 	if (!lower_dentry->d_inode->i_op->listxattr) {
-		rc = -ENOSYS;
+		rc = -EOPNOTSUPP;
 		goto out;
 	}
 	mutex_lock(&lower_dentry->d_inode->i_mutex);
@ -1102,7 +1106,7 @@ static int ecryptfs_removexattr(struct dentry *dentry, const char *name)

 	lower_dentry = ecryptfs_dentry_to_lower(dentry);
 	if (!lower_dentry->d_inode->i_op->removexattr) {
-		rc = -ENOSYS;
+		rc = -EOPNOTSUPP;
 		goto out;
 	}
 	mutex_lock(&lower_dentry->d_inode->i_mutex);
@ -1133,6 +1137,7 @@ const struct inode_operations ecryptfs_symlink_iops = {
 	.put_link = ecryptfs_put_link,
 	.permission = ecryptfs_permission,
 	.setattr = ecryptfs_setattr,
+	.getattr = ecryptfs_getattr_link,
 	.setxattr = ecryptfs_setxattr,
 	.getxattr = ecryptfs_getxattr,
 	.listxattr = ecryptfs_listxattr,
--- a/fs/ecryptfs/mmap.c
+++ b/fs/ecryptfs/mmap.c
@ -83,6 +83,19 @@ static int ecryptfs_writepage(struct page *page, struct writeback_control *wbc)
 	return rc;
 }

+static void strip_xattr_flag(char *page_virt,
+			     struct ecryptfs_crypt_stat *crypt_stat)
+{
+	if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) {
+		size_t written;
+
+		crypt_stat->flags &= ~ECRYPTFS_METADATA_IN_XATTR;
+		ecryptfs_write_crypt_stat_flags(page_virt, crypt_stat,
+						&written);
+		crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;
+	}
+}
+
 /**
 *   Header Extent:
 *     Octets 0-7:        Unencrypted file size (big-endian)
@ -98,19 +111,6 @@ static int ecryptfs_writepage(struct page *page, struct writeback_control *wbc)
 *                        (big-endian)
 *     Octet  26:         Begin RFC 2440 authentication token packet set
 */
-static void set_header_info(char *page_virt,
-			    struct ecryptfs_crypt_stat *crypt_stat)
-{
-	size_t written;
-	size_t save_num_header_bytes_at_front =
-		crypt_stat->num_header_bytes_at_front;
-
-	crypt_stat->num_header_bytes_at_front =
-		ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE;
-	ecryptfs_write_header_metadata(page_virt + 20, crypt_stat, &written);
-	crypt_stat->num_header_bytes_at_front =
-		save_num_header_bytes_at_front;
-}

 /**
 * ecryptfs_copy_up_encrypted_with_header
@ -136,8 +136,7 @@ ecryptfs_copy_up_encrypted_with_header(struct page *page,
 					   * num_extents_per_page)
 					  + extent_num_in_page);
 		size_t num_header_extents_at_front =
-			(crypt_stat->num_header_bytes_at_front
-			 / crypt_stat->extent_size);
+			(crypt_stat->metadata_size / crypt_stat->extent_size);

 		if (view_extent_num < num_header_extents_at_front) {
 			/* This is a header extent */
@ -147,9 +146,14 @@ ecryptfs_copy_up_encrypted_with_header(struct page *page,
 			memset(page_virt, 0, PAGE_CACHE_SIZE);
 			/* TODO: Support more than one header extent */
 			if (view_extent_num == 0) {
+				size_t written;
+
 				rc = ecryptfs_read_xattr_region(
 					page_virt, page->mapping->host);
-				set_header_info(page_virt, crypt_stat);
+				strip_xattr_flag(page_virt + 16, crypt_stat);
+				ecryptfs_write_header_metadata(page_virt + 20,
+							       crypt_stat,
+							       &written);
 			}
 			kunmap_atomic(page_virt, KM_USER0);
 			flush_dcache_page(page);
@ -162,7 +166,7 @@ ecryptfs_copy_up_encrypted_with_header(struct page *page,
 			/* This is an encrypted data extent */
 			loff_t lower_offset =
 				((view_extent_num * crypt_stat->extent_size)
-				 - crypt_stat->num_header_bytes_at_front);
+				 - crypt_stat->metadata_size);

 			rc = ecryptfs_read_lower_page_segment(
 				page, (lower_offset >> PAGE_CACHE_SHIFT),
--- a/fs/ecryptfs/super.c
+++ b/fs/ecryptfs/super.c
@ -86,7 +86,6 @@ static void ecryptfs_destroy_inode(struct inode *inode)
 		if (lower_dentry->d_inode) {
 			fput(inode_info->lower_file);
 			inode_info->lower_file = NULL;
-			d_drop(lower_dentry);
 		}
 	}
 	ecryptfs_destroy_crypt_stat(&inode_info->crypt_stat);