From fed8859b3ab94274c986cbdf7d27130e0545f02c Mon Sep 17 00:00:00 2001
From: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Date: Wed, 23 Feb 2011 00:54:20 -0600
Subject: eCryptfs: Remove ECRYPTFS_NEW_FILE crypt stat flag

Now that grow_file() is not called in the ecryptfs_create() path, the
ECRYPTFS_NEW_FILE flag is no longer needed. It helped
ecryptfs_readpage() know not to decrypt zeroes that were read from the
lower file in the grow_file() path.

Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
---
 fs/ecryptfs/ecryptfs_kernel.h | 25 ++++++++++++-------------
 1 file changed, 12 insertions(+), 13 deletions(-)

(limited to 'fs/ecryptfs/ecryptfs_kernel.h')

diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h
index e00753496e3e..427478e29760 100644
--- a/fs/ecryptfs/ecryptfs_kernel.h
+++ b/fs/ecryptfs/ecryptfs_kernel.h
@@ -257,19 +257,18 @@ struct ecryptfs_filename {
 struct ecryptfs_crypt_stat {
 #define ECRYPTFS_STRUCT_INITIALIZED   0x00000001
 #define ECRYPTFS_POLICY_APPLIED       0x00000002
-#define ECRYPTFS_NEW_FILE             0x00000004
-#define ECRYPTFS_ENCRYPTED            0x00000008
-#define ECRYPTFS_SECURITY_WARNING     0x00000010
-#define ECRYPTFS_ENABLE_HMAC          0x00000020
-#define ECRYPTFS_ENCRYPT_IV_PAGES     0x00000040
-#define ECRYPTFS_KEY_VALID            0x00000080
-#define ECRYPTFS_METADATA_IN_XATTR    0x00000100
-#define ECRYPTFS_VIEW_AS_ENCRYPTED    0x00000200
-#define ECRYPTFS_KEY_SET              0x00000400
-#define ECRYPTFS_ENCRYPT_FILENAMES    0x00000800
-#define ECRYPTFS_ENCFN_USE_MOUNT_FNEK 0x00001000
-#define ECRYPTFS_ENCFN_USE_FEK        0x00002000
-#define ECRYPTFS_UNLINK_SIGS	      0x00004000
+#define ECRYPTFS_ENCRYPTED            0x00000004
+#define ECRYPTFS_SECURITY_WARNING     0x00000008
+#define ECRYPTFS_ENABLE_HMAC          0x00000010
+#define ECRYPTFS_ENCRYPT_IV_PAGES     0x00000020
+#define ECRYPTFS_KEY_VALID            0x00000040
+#define ECRYPTFS_METADATA_IN_XATTR    0x00000080
+#define ECRYPTFS_VIEW_AS_ENCRYPTED    0x00000100
+#define ECRYPTFS_KEY_SET              0x00000200
+#define ECRYPTFS_ENCRYPT_FILENAMES    0x00000400
+#define ECRYPTFS_ENCFN_USE_MOUNT_FNEK 0x00000800
+#define ECRYPTFS_ENCFN_USE_FEK        0x00001000
+#define ECRYPTFS_UNLINK_SIGS          0x00002000
 	u32 flags;
 	unsigned int file_version;
 	size_t iv_bytes;
-- 
cgit v1.2.3


From 57db4e8d73ef2b5e94a3f412108dff2576670a8a Mon Sep 17 00:00:00 2001
From: Thieu Le <thieule@chromium.org>
Date: Tue, 8 Mar 2011 16:26:03 -0800
Subject: ecryptfs: modify write path to encrypt page in writepage

Change the write path to encrypt the data only when the page is written to
disk in ecryptfs_writepage. Previously, ecryptfs encrypts the page in
ecryptfs_write_end which means that if there are multiple write requests to
the same page, ecryptfs ends up re-encrypting that page over and over again.
This patch minimizes the number of encryptions needed.

Signed-off-by: Thieu Le <thieule@chromium.org>
[tyhicks: Changed NULL .drop_inode sop pointer to generic_drop_inode]
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
---
 fs/ecryptfs/ecryptfs_kernel.h |  1 -
 fs/ecryptfs/file.c            |  9 ++++++++-
 fs/ecryptfs/main.c            |  2 --
 fs/ecryptfs/mmap.c            | 41 +++++++++++++++++++++++++++--------------
 fs/ecryptfs/read_write.c      | 12 ++----------
 fs/ecryptfs/super.c           |  3 +--
 6 files changed, 38 insertions(+), 30 deletions(-)

(limited to 'fs/ecryptfs/ecryptfs_kernel.h')

diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h
index 427478e29760..3ef5b0030231 100644
--- a/fs/ecryptfs/ecryptfs_kernel.h
+++ b/fs/ecryptfs/ecryptfs_kernel.h
@@ -296,7 +296,6 @@ struct ecryptfs_inode_info {
 	struct inode vfs_inode;
 	struct inode *wii_inode;
 	struct file *lower_file;
-	struct mutex lower_file_mutex;
 	struct ecryptfs_crypt_stat crypt_stat;
 };
 
diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c
index 7d1050e254f9..cedc913d11ba 100644
--- a/fs/ecryptfs/file.c
+++ b/fs/ecryptfs/file.c
@@ -273,7 +273,14 @@ static int ecryptfs_release(struct inode *inode, struct file *file)
 static int
 ecryptfs_fsync(struct file *file, int datasync)
 {
-	return vfs_fsync(ecryptfs_file_to_lower(file), datasync);
+	int rc = 0;
+
+	rc = generic_file_fsync(file, datasync);
+	if (rc)
+		goto out;
+	rc = vfs_fsync(ecryptfs_file_to_lower(file), datasync);
+out:
+	return rc;
 }
 
 static int ecryptfs_fasync(int fd, struct file *file, int flag)
diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c
index 758323a0f09a..63e412cf0fa1 100644
--- a/fs/ecryptfs/main.c
+++ b/fs/ecryptfs/main.c
@@ -122,7 +122,6 @@ int ecryptfs_init_persistent_file(struct dentry *ecryptfs_dentry)
 		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 =
@@ -138,7 +137,6 @@ int ecryptfs_init_persistent_file(struct dentry *ecryptfs_dentry)
 			inode_info->lower_file = NULL;
 		}
 	}
-	mutex_unlock(&inode_info->lower_file_mutex);
 	return rc;
 }
 
diff --git a/fs/ecryptfs/mmap.c b/fs/ecryptfs/mmap.c
index 519af27db059..5e150131eb9d 100644
--- a/fs/ecryptfs/mmap.c
+++ b/fs/ecryptfs/mmap.c
@@ -62,6 +62,18 @@ static int ecryptfs_writepage(struct page *page, struct writeback_control *wbc)
 {
 	int rc;
 
+	/*
+	 * Refuse to write the page out if we are called from reclaim context
+	 * since our writepage() path may potentially allocate memory when
+	 * calling into the lower fs vfs_write() which may in turn invoke
+	 * us again.
+	 */
+	if (current->flags & PF_MEMALLOC) {
+		redirty_page_for_writepage(wbc, page);
+		rc = 0;
+		goto out;
+	}
+
 	rc = ecryptfs_encrypt_page(page);
 	if (rc) {
 		ecryptfs_printk(KERN_WARNING, "Error encrypting "
@@ -70,8 +82,8 @@ static int ecryptfs_writepage(struct page *page, struct writeback_control *wbc)
 		goto out;
 	}
 	SetPageUptodate(page);
-	unlock_page(page);
 out:
+	unlock_page(page);
 	return rc;
 }
 
@@ -481,6 +493,7 @@ static int ecryptfs_write_end(struct file *file,
 	struct ecryptfs_crypt_stat *crypt_stat =
 		&ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat;
 	int rc;
+	int need_unlock_page = 1;
 
 	ecryptfs_printk(KERN_DEBUG, "Calling fill_zeros_to_end_of_page"
 			"(page w/ index = [0x%.16lx], to = [%d])\n", index, to);
@@ -501,26 +514,26 @@ static int ecryptfs_write_end(struct file *file,
 			"zeros in page with index = [0x%.16lx]\n", index);
 		goto out;
 	}
-	rc = ecryptfs_encrypt_page(page);
-	if (rc) {
-		ecryptfs_printk(KERN_WARNING, "Error encrypting page (upper "
-				"index [0x%.16lx])\n", index);
-		goto out;
-	}
+	set_page_dirty(page);
+	unlock_page(page);
+	need_unlock_page = 0;
 	if (pos + copied > i_size_read(ecryptfs_inode)) {
 		i_size_write(ecryptfs_inode, pos + copied);
 		ecryptfs_printk(KERN_DEBUG, "Expanded file size to "
 			"[0x%.16llx]\n",
 			(unsigned long long)i_size_read(ecryptfs_inode));
+		balance_dirty_pages_ratelimited(mapping);
+		rc = ecryptfs_write_inode_size_to_metadata(ecryptfs_inode);
+		if (rc) {
+			printk(KERN_ERR "Error writing inode size to metadata; "
+			       "rc = [%d]\n", rc);
+			goto out;
+		}
 	}
-	rc = ecryptfs_write_inode_size_to_metadata(ecryptfs_inode);
-	if (rc)
-		printk(KERN_ERR "Error writing inode size to metadata; "
-		       "rc = [%d]\n", rc);
-	else
-		rc = copied;
+	rc = copied;
 out:
-	unlock_page(page);
+	if (need_unlock_page)
+		unlock_page(page);
 	page_cache_release(page);
 	return rc;
 }
diff --git a/fs/ecryptfs/read_write.c b/fs/ecryptfs/read_write.c
index db184ef15d3d..85d430963116 100644
--- a/fs/ecryptfs/read_write.c
+++ b/fs/ecryptfs/read_write.c
@@ -44,15 +44,11 @@ int ecryptfs_write_lower(struct inode *ecryptfs_inode, char *data,
 	ssize_t rc;
 
 	inode_info = ecryptfs_inode_to_private(ecryptfs_inode);
-	mutex_lock(&inode_info->lower_file_mutex);
 	BUG_ON(!inode_info->lower_file);
-	inode_info->lower_file->f_pos = offset;
 	fs_save = get_fs();
 	set_fs(get_ds());
-	rc = vfs_write(inode_info->lower_file, data, size,
-		       &inode_info->lower_file->f_pos);
+	rc = vfs_write(inode_info->lower_file, data, size, &offset);
 	set_fs(fs_save);
-	mutex_unlock(&inode_info->lower_file_mutex);
 	mark_inode_dirty_sync(ecryptfs_inode);
 	return rc;
 }
@@ -234,15 +230,11 @@ int ecryptfs_read_lower(char *data, loff_t offset, size_t size,
 	mm_segment_t fs_save;
 	ssize_t rc;
 
-	mutex_lock(&inode_info->lower_file_mutex);
 	BUG_ON(!inode_info->lower_file);
-	inode_info->lower_file->f_pos = offset;
 	fs_save = get_fs();
 	set_fs(get_ds());
-	rc = vfs_read(inode_info->lower_file, data, size,
-		      &inode_info->lower_file->f_pos);
+	rc = vfs_read(inode_info->lower_file, data, size, &offset);
 	set_fs(fs_save);
-	mutex_unlock(&inode_info->lower_file_mutex);
 	return rc;
 }
 
diff --git a/fs/ecryptfs/super.c b/fs/ecryptfs/super.c
index 3042fe123a34..bacc882e1ae4 100644
--- a/fs/ecryptfs/super.c
+++ b/fs/ecryptfs/super.c
@@ -55,7 +55,6 @@ 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);
 	inode_info->lower_file = NULL;
 	inode = &inode_info->vfs_inode;
 out:
@@ -198,7 +197,7 @@ static int ecryptfs_show_options(struct seq_file *m, struct vfsmount *mnt)
 const struct super_operations ecryptfs_sops = {
 	.alloc_inode = ecryptfs_alloc_inode,
 	.destroy_inode = ecryptfs_destroy_inode,
-	.drop_inode = generic_delete_inode,
+	.drop_inode = generic_drop_inode,
 	.statfs = ecryptfs_statfs,
 	.remount_fs = NULL,
 	.evict_inode = ecryptfs_evict_inode,
-- 
cgit v1.2.3


From cf35ca69131d5fc8febb74629d173e0731bf49c0 Mon Sep 17 00:00:00 2001
From: Roberto Sassu <roberto.sassu@polito.it>
Date: Mon, 21 Mar 2011 16:00:51 +0100
Subject: eCryptfs: removed num_global_auth_toks from ecryptfs_mount_crypt_stat

This patch removes the 'num_global_auth_toks' field of the
ecryptfs_mount_crypt_stat structure, used to count the number of items in
the 'global_auth_tok_list' list. This variable is not needed because there
are no checks based upon it.

Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
---
 fs/ecryptfs/crypto.c          | 1 -
 fs/ecryptfs/ecryptfs_kernel.h | 1 -
 fs/ecryptfs/keystore.c        | 1 -
 3 files changed, 3 deletions(-)

(limited to 'fs/ecryptfs/ecryptfs_kernel.h')

diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
index 98a2a314ea68..d2a70a4561f9 100644
--- a/fs/ecryptfs/crypto.c
+++ b/fs/ecryptfs/crypto.c
@@ -266,7 +266,6 @@ void ecryptfs_destroy_mount_crypt_stat(
 				 &mount_crypt_stat->global_auth_tok_list,
 				 mount_crypt_stat_list) {
 		list_del(&auth_tok->mount_crypt_stat_list);
-		mount_crypt_stat->num_global_auth_toks--;
 		if (auth_tok->global_auth_tok_key
 		    && !(auth_tok->flags & ECRYPTFS_AUTH_TOK_INVALID))
 			key_put(auth_tok->global_auth_tok_key);
diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h
index 3ef5b0030231..6c6b8261092e 100644
--- a/fs/ecryptfs/ecryptfs_kernel.h
+++ b/fs/ecryptfs/ecryptfs_kernel.h
@@ -378,7 +378,6 @@ struct ecryptfs_mount_crypt_stat {
 	u32 flags;
 	struct list_head global_auth_tok_list;
 	struct mutex global_auth_tok_list_mutex;
-	size_t num_global_auth_toks;
 	size_t global_default_cipher_key_size;
 	size_t global_default_fn_cipher_key_bytes;
 	unsigned char global_default_cipher_name[ECRYPTFS_MAX_CIPHER_NAME_SIZE
diff --git a/fs/ecryptfs/keystore.c b/fs/ecryptfs/keystore.c
index 4feb78c23651..523e51dec66e 100644
--- a/fs/ecryptfs/keystore.c
+++ b/fs/ecryptfs/keystore.c
@@ -2454,7 +2454,6 @@ ecryptfs_add_global_auth_tok(struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
 	mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex);
 	list_add(&new_auth_tok->mount_crypt_stat_list,
 		 &mount_crypt_stat->global_auth_tok_list);
-	mount_crypt_stat->num_global_auth_toks++;
 	mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex);
 out:
 	return rc;
-- 
cgit v1.2.3


From 7762e230fd31fcc1abc03ba32ee957fadc8eafb4 Mon Sep 17 00:00:00 2001
From: Roberto Sassu <roberto.sassu@polito.it>
Date: Mon, 21 Mar 2011 16:00:52 +0100
Subject: eCryptfs: modified size of keysig in the ecryptfs_key_sig structure

The size of the 'keysig' array is incremented of one byte in order to make
room for the NULL character. The 'keysig' variable is used, in the function
ecryptfs_generate_key_packet_set(), to find an authentication token with
the given signature and is printed a debug message if it cannot be
retrieved.

Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
---
 fs/ecryptfs/ecryptfs_kernel.h | 2 +-
 fs/ecryptfs/keystore.c        | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

(limited to 'fs/ecryptfs/ecryptfs_kernel.h')

diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h
index 6c6b8261092e..40c93fe41cc3 100644
--- a/fs/ecryptfs/ecryptfs_kernel.h
+++ b/fs/ecryptfs/ecryptfs_kernel.h
@@ -233,7 +233,7 @@ ecryptfs_get_key_payload_data(struct key *key)
 
 struct ecryptfs_key_sig {
 	struct list_head crypt_stat_list;
-	char keysig[ECRYPTFS_SIG_SIZE_HEX];
+	char keysig[ECRYPTFS_SIG_SIZE_HEX + 1];
 };
 
 struct ecryptfs_filename {
diff --git a/fs/ecryptfs/keystore.c b/fs/ecryptfs/keystore.c
index 523e51dec66e..bd139dfad8e7 100644
--- a/fs/ecryptfs/keystore.c
+++ b/fs/ecryptfs/keystore.c
@@ -2425,6 +2425,7 @@ int ecryptfs_add_keysig(struct ecryptfs_crypt_stat *crypt_stat, char *sig)
 		return -ENOMEM;
 	}
 	memcpy(new_key_sig->keysig, sig, ECRYPTFS_SIG_SIZE_HEX);
+	new_key_sig->keysig[ECRYPTFS_SIG_SIZE_HEX] = '\0';
 	/* Caller must hold keysig_list_mutex */
 	list_add(&new_key_sig->crypt_stat_list, &crypt_stat->keysig_list);
 
-- 
cgit v1.2.3


From 0e1fc5ef470cc1d157005c437a434868d59fead4 Mon Sep 17 00:00:00 2001
From: Roberto Sassu <roberto.sassu@polito.it>
Date: Mon, 21 Mar 2011 16:00:53 +0100
Subject: eCryptfs: verify authentication tokens before their use

Authentication tokens content may change if another requestor calls the
update() method of the corresponding key. The new function
ecryptfs_verify_auth_tok_from_key() retrieves the authentication token from
the provided key and verifies if it is still valid before being used to
encrypt or decrypt an eCryptfs file.

Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
[tyhicks: Minor formatting changes]
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
---
 fs/ecryptfs/ecryptfs_kernel.h |   1 -
 fs/ecryptfs/keystore.c        | 211 ++++++++++++++++++++++++++----------------
 fs/ecryptfs/main.c            |   4 +-
 3 files changed, 135 insertions(+), 81 deletions(-)

(limited to 'fs/ecryptfs/ecryptfs_kernel.h')

diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h
index 40c93fe41cc3..bd3cafd0949d 100644
--- a/fs/ecryptfs/ecryptfs_kernel.h
+++ b/fs/ecryptfs/ecryptfs_kernel.h
@@ -331,7 +331,6 @@ struct ecryptfs_global_auth_tok {
 	u32 flags;
 	struct list_head mount_crypt_stat_list;
 	struct key *global_auth_tok_key;
-	struct ecryptfs_auth_tok *global_auth_tok;
 	unsigned char sig[ECRYPTFS_SIG_SIZE_HEX + 1];
 };
 
diff --git a/fs/ecryptfs/keystore.c b/fs/ecryptfs/keystore.c
index bd139dfad8e7..3c4039cc18d1 100644
--- a/fs/ecryptfs/keystore.c
+++ b/fs/ecryptfs/keystore.c
@@ -65,6 +65,24 @@ static int process_request_key_err(long err_code)
 	return rc;
 }
 
+static int process_find_global_auth_tok_for_sig_err(int err_code)
+{
+	int rc = err_code;
+
+	switch (err_code) {
+	case -ENOENT:
+		ecryptfs_printk(KERN_WARNING, "Missing auth tok\n");
+		break;
+	case -EINVAL:
+		ecryptfs_printk(KERN_WARNING, "Invalid auth tok\n");
+		break;
+	default:
+		rc = process_request_key_err(err_code);
+		break;
+	}
+	return rc;
+}
+
 /**
  * ecryptfs_parse_packet_length
  * @data: Pointer to memory containing length at offset
@@ -403,27 +421,117 @@ out:
 	return rc;
 }
 
+/**
+ * ecryptfs_verify_version
+ * @version: The version number to confirm
+ *
+ * Returns zero on good version; non-zero otherwise
+ */
+static int ecryptfs_verify_version(u16 version)
+{
+	int rc = 0;
+	unsigned char major;
+	unsigned char minor;
+
+	major = ((version >> 8) & 0xFF);
+	minor = (version & 0xFF);
+	if (major != ECRYPTFS_VERSION_MAJOR) {
+		ecryptfs_printk(KERN_ERR, "Major version number mismatch. "
+				"Expected [%d]; got [%d]\n",
+				ECRYPTFS_VERSION_MAJOR, major);
+		rc = -EINVAL;
+		goto out;
+	}
+	if (minor != ECRYPTFS_VERSION_MINOR) {
+		ecryptfs_printk(KERN_ERR, "Minor version number mismatch. "
+				"Expected [%d]; got [%d]\n",
+				ECRYPTFS_VERSION_MINOR, minor);
+		rc = -EINVAL;
+		goto out;
+	}
+out:
+	return rc;
+}
+
+/**
+ * ecryptfs_verify_auth_tok_from_key
+ * @auth_tok_key: key containing the authentication token
+ * @auth_tok: authentication token
+ *
+ * Returns zero on valid auth tok; -EINVAL otherwise
+ */
+static int
+ecryptfs_verify_auth_tok_from_key(struct key *auth_tok_key,
+				  struct ecryptfs_auth_tok **auth_tok)
+{
+	int rc = 0;
+
+	(*auth_tok) = ecryptfs_get_key_payload_data(auth_tok_key);
+	if (ecryptfs_verify_version((*auth_tok)->version)) {
+		printk(KERN_ERR "Data structure version mismatch. Userspace "
+		       "tools must match eCryptfs kernel module with major "
+		       "version [%d] and minor version [%d]\n",
+		       ECRYPTFS_VERSION_MAJOR, ECRYPTFS_VERSION_MINOR);
+		rc = -EINVAL;
+		goto out;
+	}
+	if ((*auth_tok)->token_type != ECRYPTFS_PASSWORD
+	    && (*auth_tok)->token_type != ECRYPTFS_PRIVATE_KEY) {
+		printk(KERN_ERR "Invalid auth_tok structure "
+		       "returned from key query\n");
+		rc = -EINVAL;
+		goto out;
+	}
+out:
+	return rc;
+}
+
 static int
 ecryptfs_find_global_auth_tok_for_sig(
-	struct ecryptfs_global_auth_tok **global_auth_tok,
+	struct key **auth_tok_key,
+	struct ecryptfs_auth_tok **auth_tok,
 	struct ecryptfs_mount_crypt_stat *mount_crypt_stat, char *sig)
 {
 	struct ecryptfs_global_auth_tok *walker;
 	int rc = 0;
 
-	(*global_auth_tok) = NULL;
+	(*auth_tok_key) = NULL;
+	(*auth_tok) = NULL;
 	mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex);
 	list_for_each_entry(walker,
 			    &mount_crypt_stat->global_auth_tok_list,
 			    mount_crypt_stat_list) {
-		if (memcmp(walker->sig, sig, ECRYPTFS_SIG_SIZE_HEX) == 0) {
-			rc = key_validate(walker->global_auth_tok_key);
-			if (!rc)
-				(*global_auth_tok) = walker;
+		if (memcmp(walker->sig, sig, ECRYPTFS_SIG_SIZE_HEX))
+			continue;
+
+		if (walker->flags & ECRYPTFS_AUTH_TOK_INVALID) {
+			rc = -EINVAL;
 			goto out;
 		}
+
+		rc = key_validate(walker->global_auth_tok_key);
+		if (rc) {
+			if (rc == -EKEYEXPIRED)
+				goto out;
+			goto out_invalid_auth_tok;
+		}
+
+		rc = ecryptfs_verify_auth_tok_from_key(
+				walker->global_auth_tok_key, auth_tok);
+		if (rc)
+			goto out_invalid_auth_tok;
+
+		(*auth_tok_key) = walker->global_auth_tok_key;
+		key_get(*auth_tok_key);
+		goto out;
 	}
-	rc = -EINVAL;
+	rc = -ENOENT;
+	goto out;
+out_invalid_auth_tok:
+	printk(KERN_WARNING "Invalidating auth tok with sig = [%s]\n", sig);
+	walker->flags |= ECRYPTFS_AUTH_TOK_INVALID;
+	key_put(walker->global_auth_tok_key);
+	walker->global_auth_tok_key = NULL;
 out:
 	mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex);
 	return rc;
@@ -451,14 +559,11 @@ ecryptfs_find_auth_tok_for_sig(
 	struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
 	char *sig)
 {
-	struct ecryptfs_global_auth_tok *global_auth_tok;
 	int rc = 0;
 
-	(*auth_tok_key) = NULL;
-	(*auth_tok) = NULL;
-	if (ecryptfs_find_global_auth_tok_for_sig(&global_auth_tok,
-						  mount_crypt_stat, sig)) {
-
+	rc = ecryptfs_find_global_auth_tok_for_sig(auth_tok_key, auth_tok,
+						   mount_crypt_stat, sig);
+	if (rc == -ENOENT) {
 		/* if the flag ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY is set in the
 		 * mount_crypt_stat structure, we prevent to use auth toks that
 		 * are not inserted through the ecryptfs_add_global_auth_tok
@@ -470,8 +575,7 @@ ecryptfs_find_auth_tok_for_sig(
 
 		rc = ecryptfs_keyring_auth_tok_for_sig(auth_tok_key, auth_tok,
 						       sig);
-	} else
-		(*auth_tok) = global_auth_tok->global_auth_tok;
+	}
 	return rc;
 }
 
@@ -1520,38 +1624,6 @@ out:
 	return rc;
 }
 
-/**
- * ecryptfs_verify_version
- * @version: The version number to confirm
- *
- * Returns zero on good version; non-zero otherwise
- */
-static int ecryptfs_verify_version(u16 version)
-{
-	int rc = 0;
-	unsigned char major;
-	unsigned char minor;
-
-	major = ((version >> 8) & 0xFF);
-	minor = (version & 0xFF);
-	if (major != ECRYPTFS_VERSION_MAJOR) {
-		ecryptfs_printk(KERN_ERR, "Major version number mismatch. "
-				"Expected [%d]; got [%d]\n",
-				ECRYPTFS_VERSION_MAJOR, major);
-		rc = -EINVAL;
-		goto out;
-	}
-	if (minor != ECRYPTFS_VERSION_MINOR) {
-		ecryptfs_printk(KERN_ERR, "Minor version number mismatch. "
-				"Expected [%d]; got [%d]\n",
-				ECRYPTFS_VERSION_MINOR, minor);
-		rc = -EINVAL;
-		goto out;
-	}
-out:
-	return rc;
-}
-
 int ecryptfs_keyring_auth_tok_for_sig(struct key **auth_tok_key,
 				      struct ecryptfs_auth_tok **auth_tok,
 				      char *sig)
@@ -1566,29 +1638,12 @@ int ecryptfs_keyring_auth_tok_for_sig(struct key **auth_tok_key,
 		(*auth_tok_key) = NULL;
 		goto out;
 	}
-	(*auth_tok) = ecryptfs_get_key_payload_data(*auth_tok_key);
-	if (ecryptfs_verify_version((*auth_tok)->version)) {
-		printk(KERN_ERR
-		       "Data structure version mismatch. "
-		       "Userspace tools must match eCryptfs "
-		       "kernel module with major version [%d] "
-		       "and minor version [%d]\n",
-		       ECRYPTFS_VERSION_MAJOR,
-		       ECRYPTFS_VERSION_MINOR);
-		rc = -EINVAL;
-		goto out_release_key;
-	}
-	if ((*auth_tok)->token_type != ECRYPTFS_PASSWORD
-	    && (*auth_tok)->token_type != ECRYPTFS_PRIVATE_KEY) {
-		printk(KERN_ERR "Invalid auth_tok structure "
-		       "returned from key query\n");
-		rc = -EINVAL;
-		goto out_release_key;
-	}
-out_release_key:
+
+	rc = ecryptfs_verify_auth_tok_from_key(*auth_tok_key, auth_tok);
 	if (rc) {
 		key_put(*auth_tok_key);
 		(*auth_tok_key) = NULL;
+		goto out;
 	}
 out:
 	return rc;
@@ -2325,7 +2380,7 @@ ecryptfs_generate_key_packet_set(char *dest_base,
 				 size_t max)
 {
 	struct ecryptfs_auth_tok *auth_tok;
-	struct ecryptfs_global_auth_tok *global_auth_tok;
+	struct key *auth_tok_key = NULL;
 	struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
 		&ecryptfs_superblock_to_private(
 			ecryptfs_dentry->d_sb)->mount_crypt_stat;
@@ -2344,21 +2399,16 @@ ecryptfs_generate_key_packet_set(char *dest_base,
 	list_for_each_entry(key_sig, &crypt_stat->keysig_list,
 			    crypt_stat_list) {
 		memset(key_rec, 0, sizeof(*key_rec));
-		rc = ecryptfs_find_global_auth_tok_for_sig(&global_auth_tok,
+		rc = ecryptfs_find_global_auth_tok_for_sig(&auth_tok_key,
+							   &auth_tok,
 							   mount_crypt_stat,
 							   key_sig->keysig);
 		if (rc) {
-			printk(KERN_ERR "Error attempting to get the global "
-			       "auth_tok; rc = [%d]\n", rc);
+			printk(KERN_WARNING "Unable to retrieve auth tok with "
+			       "sig = [%s]\n", key_sig->keysig);
+			rc = process_find_global_auth_tok_for_sig_err(rc);
 			goto out_free;
 		}
-		if (global_auth_tok->flags & ECRYPTFS_AUTH_TOK_INVALID) {
-			printk(KERN_WARNING
-			       "Skipping invalid auth tok with sig = [%s]\n",
-			       global_auth_tok->sig);
-			continue;
-		}
-		auth_tok = global_auth_tok->global_auth_tok;
 		if (auth_tok->token_type == ECRYPTFS_PASSWORD) {
 			rc = write_tag_3_packet((dest_base + (*len)),
 						&max, auth_tok,
@@ -2396,6 +2446,8 @@ ecryptfs_generate_key_packet_set(char *dest_base,
 			rc = -EINVAL;
 			goto out_free;
 		}
+		key_put(auth_tok_key);
+		auth_tok_key = NULL;
 	}
 	if (likely(max > 0)) {
 		dest_base[(*len)] = 0x00;
@@ -2408,6 +2460,9 @@ out_free:
 out:
 	if (rc)
 		(*len) = 0;
+	if (auth_tok_key)
+		key_put(auth_tok_key);
+
 	mutex_unlock(&crypt_stat->keysig_list_mutex);
 	return rc;
 }
diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c
index 63e412cf0fa1..520d05f5ad01 100644
--- a/fs/ecryptfs/main.c
+++ b/fs/ecryptfs/main.c
@@ -239,14 +239,14 @@ static int ecryptfs_init_global_auth_toks(
 	struct ecryptfs_mount_crypt_stat *mount_crypt_stat)
 {
 	struct ecryptfs_global_auth_tok *global_auth_tok;
+	struct ecryptfs_auth_tok *auth_tok;
 	int rc = 0;
 
 	list_for_each_entry(global_auth_tok,
 			    &mount_crypt_stat->global_auth_tok_list,
 			    mount_crypt_stat_list) {
 		rc = ecryptfs_keyring_auth_tok_for_sig(
-			&global_auth_tok->global_auth_tok_key,
-			&global_auth_tok->global_auth_tok,
+			&global_auth_tok->global_auth_tok_key, &auth_tok,
 			global_auth_tok->sig);
 		if (rc) {
 			printk(KERN_ERR "Could not find valid key in user "
-- 
cgit v1.2.3


From 332ab16f830f59e7621ae8eb2c353dc135a316f6 Mon Sep 17 00:00:00 2001
From: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Date: Thu, 14 Apr 2011 15:35:11 -0500
Subject: eCryptfs: Add reference counting to lower files

For any given lower inode, eCryptfs keeps only one lower file open and
multiplexes all eCryptfs file operations through that lower file. The
lower file was considered "persistent" and stayed open from the first
lookup through the lifetime of the inode.

This patch keeps the notion of a single, per-inode lower file, but adds
reference counting around the lower file so that it is closed when not
currently in use. If the reference count is at 0 when an operation (such
as open, create, etc.) needs to use the lower file, a new lower file is
opened. Since the file is no longer persistent, all references to the
term persistent file are changed to lower file.

Locking is added around the sections of code that opens the lower file
and assign the pointer in the inode info, as well as the code the fputs
the lower file when all eCryptfs users are done with it.

This patch is needed to fix issues, when mounted on top of the NFSv3
client, where the lower file is left silly renamed until the eCryptfs
inode is destroyed.

Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
---
 fs/ecryptfs/ecryptfs_kernel.h |  5 ++-
 fs/ecryptfs/file.c            | 22 ++++++-------
 fs/ecryptfs/inode.c           | 30 ++++++++++++------
 fs/ecryptfs/kthread.c         |  6 ++--
 fs/ecryptfs/main.c            | 72 ++++++++++++++++++++++++++++++-------------
 fs/ecryptfs/super.c           | 16 +++-------
 6 files changed, 92 insertions(+), 59 deletions(-)

(limited to 'fs/ecryptfs/ecryptfs_kernel.h')

diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h
index bd3cafd0949d..380bee1094c3 100644
--- a/fs/ecryptfs/ecryptfs_kernel.h
+++ b/fs/ecryptfs/ecryptfs_kernel.h
@@ -295,6 +295,8 @@ 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;
 };
@@ -757,7 +759,8 @@ 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 cedc913d11ba..146c4edff70c 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);
@@ -232,7 +232,7 @@ 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);
@@ -245,6 +245,8 @@ 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 +256,13 @@ 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 72d357649599..f6b388638c3d 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;
 }
@@ -230,7 +229,7 @@ int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry,
 	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 +276,15 @@ 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 */
@@ -322,6 +322,8 @@ out_put:
 	mntput(lower_mnt);
 	d_drop(ecryptfs_dentry);
 out:
+	if (put_lower)
+		ecryptfs_put_lower_file(ecryptfs_dentry->d_inode);
 	return rc;
 }
 
@@ -757,8 +759,11 @@ 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) {
@@ -836,6 +841,7 @@ static int truncate_upper(struct dentry *dentry, struct iattr *ia,
 			lower_ia->ia_valid &= ~ATTR_SIZE;
 	}
 out:
+	ecryptfs_put_lower_file(inode);
 	return rc;
 }
 
@@ -911,7 +917,13 @@ 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)) {
diff --git a/fs/ecryptfs/kthread.c b/fs/ecryptfs/kthread.c
index 0851ab6980f5..69f994a7d524 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 fdb2eb0ad09e..89b93389af8e 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 bacc882e1ae4..245b517bf1b6 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);
 }
-- 
cgit v1.2.3


From 3aeb86ea4cd15f728147a3bd5469a205ada8c767 Mon Sep 17 00:00:00 2001
From: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Date: Tue, 15 Mar 2011 14:54:00 -0500
Subject: eCryptfs: Handle failed metadata read in lookup

When failing to read the lower file's crypto metadata during a lookup,
eCryptfs must continue on without throwing an error. For example, there
may be a plaintext file in the lower mount point that the user wants to
delete through the eCryptfs mount.

If an error is encountered while reading the metadata in lookup(), the
eCryptfs inode's size could be incorrect. We must be sure to reread the
plaintext inode size from the metadata when performing an open() or
setattr(). The metadata is already being read in those paths, so this
adds minimal performance overhead.

This patch introduces a flag which will track whether or not the
plaintext inode size has been read so that an incorrect i_size can be
fixed in the open() or setattr() paths.

https://bugs.launchpad.net/bugs/509180

Cc: <stable@kernel.org>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
---
 fs/ecryptfs/crypto.c          | 21 +++++++++++++++++++++
 fs/ecryptfs/ecryptfs_kernel.h |  2 ++
 fs/ecryptfs/file.c            |  3 ++-
 fs/ecryptfs/inode.c           | 18 +++---------------
 4 files changed, 28 insertions(+), 16 deletions(-)

(limited to 'fs/ecryptfs/ecryptfs_kernel.h')

diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
index d2a70a4561f9..b8d5c8091024 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 380bee1094c3..e70282775e2c 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;
@@ -628,6 +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);
diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c
index 146c4edff70c..566e5472f78c 100644
--- a/fs/ecryptfs/file.c
+++ b/fs/ecryptfs/file.c
@@ -235,7 +235,8 @@ static int ecryptfs_open(struct inode *inode, struct file *file)
 				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;
 		}
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index f6b388638c3d..2c19d362d2d4 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -225,10 +225,8 @@ 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 put_lower = 0, rc = 0;
 
 	lower_dir_dentry = lower_dentry->d_parent;
@@ -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;
@@ -937,7 +924,8 @@ 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);
-- 
cgit v1.2.3