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: Flush dirty pages in setattr
  eCryptfs: Handle failed metadata read in lookup
  eCryptfs: Add reference counting to lower files
  eCryptfs: dput dentries returned from dget_parent
  eCryptfs: Remove extra d_delete in ecryptfs_rmdir

7 files changed, 128 insertions, 79 deletions

diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
index d2a70a4..b8d5c80 100644
--- a/fs/ecryptfs/crypto.c
+++ b/fs/ecryptfs/crypto.c
@@ -1452,6 +1452,25 @@ static void set_default_header_data(struct ecryptfs_crypt_stat *crypt_stat)
 	crypt_stat->metadata_size = ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE;
 }
 
+void ecryptfs_i_size_init(const char *page_virt, struct inode *inode)
+{
+	struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
+	struct ecryptfs_crypt_stat *crypt_stat;
+	u64 file_size;
+
+	crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
+	mount_crypt_stat =
+		&ecryptfs_superblock_to_private(inode->i_sb)->mount_crypt_stat;
+	if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) {
+		file_size = i_size_read(ecryptfs_inode_to_lower(inode));
+		if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR)
+			file_size += crypt_stat->metadata_size;
+	} else
+		file_size = get_unaligned_be64(page_virt);
+	i_size_write(inode, (loff_t)file_size);
+	crypt_stat->flags |= ECRYPTFS_I_SIZE_INITIALIZED;
+}
+
 /**
  * ecryptfs_read_headers_virt
  * @page_virt: The virtual address into which to read the headers
@@ -1482,6 +1501,8 @@ static int ecryptfs_read_headers_virt(char *page_virt,
 		rc = -EINVAL;
 		goto out;
 	}
+	if (!(crypt_stat->flags & ECRYPTFS_I_SIZE_INITIALIZED))
+		ecryptfs_i_size_init(page_virt, ecryptfs_dentry->d_inode);
 	offset += MAGIC_ECRYPTFS_MARKER_SIZE_BYTES;
 	rc = ecryptfs_process_flags(crypt_stat, (page_virt + offset),
 				    &bytes_read);
diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h
index bd3cafd..e702827 100644
--- a/fs/ecryptfs/ecryptfs_kernel.h
+++ b/fs/ecryptfs/ecryptfs_kernel.h
@@ -269,6 +269,7 @@ struct ecryptfs_crypt_stat {
 #define ECRYPTFS_ENCFN_USE_MOUNT_FNEK 0x00000800
 #define ECRYPTFS_ENCFN_USE_FEK        0x00001000
 #define ECRYPTFS_UNLINK_SIGS          0x00002000
+#define ECRYPTFS_I_SIZE_INITIALIZED   0x00004000
 	u32 flags;
 	unsigned int file_version;
 	size_t iv_bytes;
@@ -295,6 +296,8 @@ struct ecryptfs_crypt_stat {
 struct ecryptfs_inode_info {
 	struct inode vfs_inode;
 	struct inode *wii_inode;
+	struct mutex lower_file_mutex;
+	atomic_t lower_file_count;
 	struct file *lower_file;
 	struct ecryptfs_crypt_stat crypt_stat;
 };
@@ -626,6 +629,7 @@ struct ecryptfs_open_req {
 int ecryptfs_interpose(struct dentry *hidden_dentry,
 		       struct dentry *this_dentry, struct super_block *sb,
 		       u32 flags);
+void ecryptfs_i_size_init(const char *page_virt, struct inode *inode);
 int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry,
 					struct dentry *lower_dentry,
 					struct inode *ecryptfs_dir_inode);
@@ -757,7 +761,8 @@ int ecryptfs_privileged_open(struct file **lower_file,
 			     struct dentry *lower_dentry,
 			     struct vfsmount *lower_mnt,
 			     const struct cred *cred);
-int ecryptfs_init_persistent_file(struct dentry *ecryptfs_dentry);
+int ecryptfs_get_lower_file(struct dentry *ecryptfs_dentry);
+void ecryptfs_put_lower_file(struct inode *inode);
 int
 ecryptfs_write_tag_70_packet(char *dest, size_t *remaining_bytes,
 			     size_t *packet_size,
diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c
index cedc913..566e547 100644
--- a/fs/ecryptfs/file.c
+++ b/fs/ecryptfs/file.c
@@ -191,10 +191,10 @@ static int ecryptfs_open(struct inode *inode, struct file *file)
 				      | ECRYPTFS_ENCRYPTED);
 	}
 	mutex_unlock(&crypt_stat->cs_mutex);
-	rc = ecryptfs_init_persistent_file(ecryptfs_dentry);
+	rc = ecryptfs_get_lower_file(ecryptfs_dentry);
 	if (rc) {
 		printk(KERN_ERR "%s: Error attempting to initialize "
-			"the persistent file for the dentry with name "
+			"the lower file for the dentry with name "
 			"[%s]; rc = [%d]\n", __func__,
 			ecryptfs_dentry->d_name.name, rc);
 		goto out_free;
@@ -202,9 +202,9 @@ static int ecryptfs_open(struct inode *inode, struct file *file)
 	if ((ecryptfs_inode_to_private(inode)->lower_file->f_flags & O_ACCMODE)
 	    == O_RDONLY && (file->f_flags & O_ACCMODE) != O_RDONLY) {
 		rc = -EPERM;
-		printk(KERN_WARNING "%s: Lower persistent file is RO; eCryptfs "
+		printk(KERN_WARNING "%s: Lower file is RO; eCryptfs "
 		       "file must hence be opened RO\n", __func__);
-		goto out_free;
+		goto out_put;
 	}
 	ecryptfs_set_file_lower(
 		file, ecryptfs_inode_to_private(inode)->lower_file);
@@ -232,10 +232,11 @@ static int ecryptfs_open(struct inode *inode, struct file *file)
 				       "Plaintext passthrough mode is not "
 				       "enabled; returning -EIO\n");
 				mutex_unlock(&crypt_stat->cs_mutex);
-				goto out_free;
+				goto out_put;
 			}
 			rc = 0;
-			crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
+			crypt_stat->flags &= ~(ECRYPTFS_I_SIZE_INITIALIZED
+					       | ECRYPTFS_ENCRYPTED);
 			mutex_unlock(&crypt_stat->cs_mutex);
 			goto out;
 		}
@@ -245,6 +246,8 @@ static int ecryptfs_open(struct inode *inode, struct file *file)
 			"[0x%.16lx] size: [0x%.16llx]\n", inode, inode->i_ino,
 			(unsigned long long)i_size_read(inode));
 	goto out;
+out_put:
+	ecryptfs_put_lower_file(inode);
 out_free:
 	kmem_cache_free(ecryptfs_file_info_cache,
 			ecryptfs_file_to_private(file));
@@ -254,17 +257,13 @@ out:
 
 static int ecryptfs_flush(struct file *file, fl_owner_t td)
 {
-	int rc = 0;
-	struct file *lower_file = NULL;
-
-	lower_file = ecryptfs_file_to_lower(file);
-	if (lower_file->f_op && lower_file->f_op->flush)
-		rc = lower_file->f_op->flush(lower_file, td);
-	return rc;
+	return file->f_mode & FMODE_WRITE
+	       ? filemap_write_and_wait(file->f_mapping) : 0;
 }
 
 static int ecryptfs_release(struct inode *inode, struct file *file)
 {
+	ecryptfs_put_lower_file(inode);
 	kmem_cache_free(ecryptfs_file_info_cache,
 			ecryptfs_file_to_private(file));
 	return 0;
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index f99051b..4d4cc6a 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -168,19 +168,18 @@ static int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry)
 				"context; rc = [%d]\n", rc);
 		goto out;
 	}
-	rc = ecryptfs_init_persistent_file(ecryptfs_dentry);
+	rc = ecryptfs_get_lower_file(ecryptfs_dentry);
 	if (rc) {
 		printk(KERN_ERR "%s: Error attempting to initialize "
-			"the persistent file for the dentry with name "
+			"the lower file for the dentry with name "
 			"[%s]; rc = [%d]\n", __func__,
 			ecryptfs_dentry->d_name.name, rc);
 		goto out;
 	}
 	rc = ecryptfs_write_metadata(ecryptfs_dentry);
-	if (rc) {
+	if (rc)
 		printk(KERN_ERR "Error writing headers; rc = [%d]\n", rc);
-		goto out;
-	}
+	ecryptfs_put_lower_file(ecryptfs_dentry->d_inode);
 out:
 	return rc;
 }
@@ -226,11 +225,9 @@ int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry,
 	struct dentry *lower_dir_dentry;
 	struct vfsmount *lower_mnt;
 	struct inode *lower_inode;
-	struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
 	struct ecryptfs_crypt_stat *crypt_stat;
 	char *page_virt = NULL;
-	u64 file_size;
-	int rc = 0;
+	int put_lower = 0, rc = 0;
 
 	lower_dir_dentry = lower_dentry->d_parent;
 	lower_mnt = mntget(ecryptfs_dentry_to_lower_mnt(
@@ -277,14 +274,15 @@ int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry,
 		rc = -ENOMEM;
 		goto out;
 	}
-	rc = ecryptfs_init_persistent_file(ecryptfs_dentry);
+	rc = ecryptfs_get_lower_file(ecryptfs_dentry);
 	if (rc) {
 		printk(KERN_ERR "%s: Error attempting to initialize "
-			"the persistent file for the dentry with name "
+			"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 */
@@ -302,18 +300,7 @@ int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry,
 		}
 		crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;
 	}
-	mount_crypt_stat = &ecryptfs_superblock_to_private(
-		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->metadata_size
-				     + i_size_read(lower_dentry->d_inode));
-		else
-			file_size = i_size_read(lower_dentry->d_inode);
-	} else {
-		file_size = get_unaligned_be64(page_virt);
-	}
-	i_size_write(ecryptfs_dentry->d_inode, (loff_t)file_size);
+	ecryptfs_i_size_init(page_virt, ecryptfs_dentry->d_inode);
 out_free_kmem:
 	kmem_cache_free(ecryptfs_header_cache_2, page_virt);
 	goto out;
@@ -322,6 +309,8 @@ out_put:
 	mntput(lower_mnt);
 	d_drop(ecryptfs_dentry);
 out:
+	if (put_lower)
+		ecryptfs_put_lower_file(ecryptfs_dentry->d_inode);
 	return rc;
 }
 
@@ -538,8 +527,6 @@ static int ecryptfs_rmdir(struct inode *dir, struct dentry *dentry)
 	dget(lower_dentry);
 	rc = vfs_rmdir(lower_dir_dentry->d_inode, lower_dentry);
 	dput(lower_dentry);
-	if (!rc)
-		d_delete(lower_dentry);
 	fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
 	dir->i_nlink = lower_dir_dentry->d_inode->i_nlink;
 	unlock_dir(lower_dir_dentry);
@@ -610,8 +597,8 @@ ecryptfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 		fsstack_copy_attr_all(old_dir, lower_old_dir_dentry->d_inode);
 out_lock:
 	unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
-	dput(lower_new_dentry->d_parent);
-	dput(lower_old_dentry->d_parent);
+	dput(lower_new_dir_dentry);
+	dput(lower_old_dir_dentry);
 	dput(lower_new_dentry);
 	dput(lower_old_dentry);
 	return rc;
@@ -759,8 +746,11 @@ static int truncate_upper(struct dentry *dentry, struct iattr *ia,
 
 	if (unlikely((ia->ia_size == i_size))) {
 		lower_ia->ia_valid &= ~ATTR_SIZE;
-		goto out;
+		return 0;
 	}
+	rc = ecryptfs_get_lower_file(dentry);
+	if (rc)
+		return rc;
 	crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
 	/* Switch on growing or shrinking file */
 	if (ia->ia_size > i_size) {
@@ -838,6 +828,7 @@ static int truncate_upper(struct dentry *dentry, struct iattr *ia,
 			lower_ia->ia_valid &= ~ATTR_SIZE;
 	}
 out:
+	ecryptfs_put_lower_file(inode);
 	return rc;
 }
 
@@ -913,7 +904,13 @@ 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);
+		if (rc) {
+			mutex_unlock(&crypt_stat->cs_mutex);
+			goto out;
+		}
 		rc = ecryptfs_read_metadata(dentry);
+		ecryptfs_put_lower_file(inode);
 		if (rc) {
 			if (!(mount_crypt_stat->flags
 			      & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)) {
@@ -927,10 +924,17 @@ static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
 				goto out;
 			}
 			rc = 0;
-			crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
+			crypt_stat->flags &= ~(ECRYPTFS_I_SIZE_INITIALIZED
+					       | ECRYPTFS_ENCRYPTED);
 		}
 	}
 	mutex_unlock(&crypt_stat->cs_mutex);
+	if (S_ISREG(inode->i_mode)) {
+		rc = filemap_write_and_wait(inode->i_mapping);
+		if (rc)
+			goto out;
+		fsstack_copy_attr_all(inode, lower_inode);
+	}
 	memcpy(&lower_ia, ia, sizeof(lower_ia));
 	if (ia->ia_valid & ATTR_FILE)
 		lower_ia.ia_file = ecryptfs_file_to_lower(ia->ia_file);
diff --git a/fs/ecryptfs/kthread.c b/fs/ecryptfs/kthread.c
index 0851ab6..69f994a 100644
--- a/fs/ecryptfs/kthread.c
+++ b/fs/ecryptfs/kthread.c
@@ -44,7 +44,7 @@ static struct task_struct *ecryptfs_kthread;
  * @ignored: ignored
  *
  * The eCryptfs kernel thread that has the responsibility of getting
- * the lower persistent file with RW permissions.
+ * the lower file with RW permissions.
  *
  * Returns zero on success; non-zero otherwise
  */
@@ -141,8 +141,8 @@ int ecryptfs_privileged_open(struct file **lower_file,
 	int rc = 0;
 
 	/* Corresponding dput() and mntput() are done when the
-	 * persistent file is fput() when the eCryptfs inode is
-	 * destroyed. */
+	 * lower file is fput() when all eCryptfs files for the inode are
+	 * released. */
 	dget(lower_dentry);
 	mntget(lower_mnt);
 	flags |= IS_RDONLY(lower_dentry->d_inode) ? O_RDONLY : O_RDWR;
diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c
index fdb2eb0..89b9338 100644
--- a/fs/ecryptfs/main.c
+++ b/fs/ecryptfs/main.c
@@ -96,7 +96,7 @@ void __ecryptfs_printk(const char *fmt, ...)
 }
 
 /**
- * ecryptfs_init_persistent_file
+ * ecryptfs_init_lower_file
  * @ecryptfs_dentry: Fully initialized eCryptfs dentry object, with
  *                   the lower dentry and the lower mount set
  *
@@ -104,42 +104,70 @@ void __ecryptfs_printk(const char *fmt, ...)
  * 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.
+ * lower file struct and associates it with the eCryptfs
+ * inode. When all eCryptfs files associated with the inode are released, the
+ * file is closed.
  *
- * The persistent file will be opened with read/write permissions, if
+ * The lower 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
+ * This function does nothing if a lower file is already
  * associated with the eCryptfs inode.
  *
  * Returns zero on success; non-zero otherwise
  */
-int ecryptfs_init_persistent_file(struct dentry *ecryptfs_dentry)
+static int ecryptfs_init_lower_file(struct dentry *dentry,
+				    struct file **lower_file)
 {
 	const struct cred *cred = current_cred();
-	struct ecryptfs_inode_info *inode_info =
-		ecryptfs_inode_to_private(ecryptfs_dentry->d_inode);
-	int rc = 0;
+	struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
+	struct vfsmount *lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry);
+	int rc;
 
-	if (!inode_info->lower_file) {
-		struct dentry *lower_dentry;
-		struct vfsmount *lower_mnt =
-			ecryptfs_dentry_to_lower_mnt(ecryptfs_dentry);
+	rc = ecryptfs_privileged_open(lower_file, lower_dentry, lower_mnt,
+				      cred);
+	if (rc) {
+		printk(KERN_ERR "Error opening lower file "
+		       "for lower_dentry [0x%p] and lower_mnt [0x%p]; "
+		       "rc = [%d]\n", lower_dentry, lower_mnt, rc);
+		(*lower_file) = NULL;
+	}
+	return rc;
+}
 
-		lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
-		rc = ecryptfs_privileged_open(&inode_info->lower_file,
-					      lower_dentry, lower_mnt, cred);
-		if (rc) {
-			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);
-			inode_info->lower_file = NULL;
-		}
+int ecryptfs_get_lower_file(struct dentry *dentry)
+{
+	struct ecryptfs_inode_info *inode_info =
+		ecryptfs_inode_to_private(dentry->d_inode);
+	int count, rc = 0;
+
+	mutex_lock(&inode_info->lower_file_mutex);
+	count = atomic_inc_return(&inode_info->lower_file_count);
+	if (WARN_ON_ONCE(count < 1))
+		rc = -EINVAL;
+	else if (count == 1) {
+		rc = ecryptfs_init_lower_file(dentry,
+					      &inode_info->lower_file);
+		if (rc)
+			atomic_set(&inode_info->lower_file_count, 0);
 	}
+	mutex_unlock(&inode_info->lower_file_mutex);
 	return rc;
 }
 
+void ecryptfs_put_lower_file(struct inode *inode)
+{
+	struct ecryptfs_inode_info *inode_info;
+
+	inode_info = ecryptfs_inode_to_private(inode);
+	if (atomic_dec_and_mutex_lock(&inode_info->lower_file_count,
+				      &inode_info->lower_file_mutex)) {
+		fput(inode_info->lower_file);
+		inode_info->lower_file = NULL;
+		mutex_unlock(&inode_info->lower_file_mutex);
+	}
+}
+
 static struct inode *ecryptfs_get_inode(struct inode *lower_inode,
 		       struct super_block *sb)
 {
diff --git a/fs/ecryptfs/super.c b/fs/ecryptfs/super.c
index bacc882..245b517 100644
--- a/fs/ecryptfs/super.c
+++ b/fs/ecryptfs/super.c
@@ -55,6 +55,8 @@ static struct inode *ecryptfs_alloc_inode(struct super_block *sb)
 	if (unlikely(!inode_info))
 		goto out;
 	ecryptfs_init_crypt_stat(&inode_info->crypt_stat);
+	mutex_init(&inode_info->lower_file_mutex);
+	atomic_set(&inode_info->lower_file_count, 0);
 	inode_info->lower_file = NULL;
 	inode = &inode_info->vfs_inode;
 out:
@@ -77,8 +79,7 @@ static void ecryptfs_i_callback(struct rcu_head *head)
  *
  * This is used during the final destruction of the inode.  All
  * allocation of memory related to the inode, including allocated
- * memory in the crypt_stat struct, will be released here. This
- * function also fput()'s the persistent file for the lower inode.
+ * memory in the crypt_stat struct, will be released here.
  * There should be no chance that this deallocation will be missed.
  */
 static void ecryptfs_destroy_inode(struct inode *inode)
@@ -86,16 +87,7 @@ static void ecryptfs_destroy_inode(struct inode *inode)
 	struct ecryptfs_inode_info *inode_info;
 
 	inode_info = ecryptfs_inode_to_private(inode);
-	if (inode_info->lower_file) {
-		struct dentry *lower_dentry =
-			inode_info->lower_file->f_dentry;
-
-		BUG_ON(!lower_dentry);
-		if (lower_dentry->d_inode) {
-			fput(inode_info->lower_file);
-			inode_info->lower_file = NULL;
-		}
-	}
+	BUG_ON(inode_info->lower_file);
 	ecryptfs_destroy_crypt_stat(&inode_info->crypt_stat);
 	call_rcu(&inode->i_rcu, ecryptfs_i_callback);
 }