1 files changed, 103 insertions, 88 deletions

diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
index f8ef0af919e7..a066e109ad9c 100644
--- a/fs/ecryptfs/crypto.c
+++ b/fs/ecryptfs/crypto.c
@@ -355,8 +355,11 @@ static int encrypt_scatterlist(struct ecryptfs_crypt_stat *crypt_stat,
         }
         /* Consider doing this once, when the file is opened */
         mutex_lock(&crypt_stat->cs_tfm_mutex);
-        rc = crypto_blkcipher_setkey(crypt_stat->tfm, crypt_stat->key,
-                                     crypt_stat->key_size);
+        if (!(crypt_stat->flags & ECRYPTFS_KEY_SET)) {
+                rc = crypto_blkcipher_setkey(crypt_stat->tfm, crypt_stat->key,
+                                             crypt_stat->key_size);
+                crypt_stat->flags |= ECRYPTFS_KEY_SET;
+        }
         if (rc) {
                 ecryptfs_printk(KERN_ERR, "Error setting key; rc = [%d]\n",
                                 rc);
@@ -376,11 +379,10 @@ out:
  *
  * Convert an eCryptfs page index into a lower byte offset
  */
-void ecryptfs_lower_offset_for_extent(loff_t *offset, loff_t extent_num,
-                                      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->extent_size
-                      * crypt_stat->num_header_extents_at_front)
+        (*offset) = (crypt_stat->num_header_bytes_at_front
                      + (crypt_stat->extent_size * extent_num));
 }
 
@@ -842,15 +844,13 @@ 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_extents_at_front = 0;
+                crypt_stat->num_header_bytes_at_front = 0;
         else {
                 if (PAGE_CACHE_SIZE <= ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE)
-                        crypt_stat->num_header_extents_at_front =
-                                (ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE
-                                 / crypt_stat->extent_size);
+                        crypt_stat->num_header_bytes_at_front =
+                                ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE;
                 else
-                        crypt_stat->num_header_extents_at_front =
-                                (PAGE_CACHE_SIZE / crypt_stat->extent_size);
+                        crypt_stat->num_header_bytes_at_front = PAGE_CACHE_SIZE;
         }
 }
 
@@ -1128,7 +1128,7 @@ write_ecryptfs_flags(char *page_virt, struct ecryptfs_crypt_stat *crypt_stat,
 
 struct ecryptfs_cipher_code_str_map_elem {
         char cipher_str[16];
-        u16 cipher_code;
+        u8 cipher_code;
 };
 
 /* Add support for additional ciphers by adding elements here. The
@@ -1152,10 +1152,10 @@ ecryptfs_cipher_code_str_map[] = {
  *
  * Returns zero on no match, or the cipher code on match
  */
-u16 ecryptfs_code_for_cipher_string(struct ecryptfs_crypt_stat *crypt_stat)
+u8 ecryptfs_code_for_cipher_string(struct ecryptfs_crypt_stat *crypt_stat)
 {
         int i;
-        u16 code = 0;
+        u8 code = 0;
         struct ecryptfs_cipher_code_str_map_elem *map =
                 ecryptfs_cipher_code_str_map;
 
@@ -1187,7 +1187,7 @@ u16 ecryptfs_code_for_cipher_string(struct ecryptfs_crypt_stat *crypt_stat)
  *
  * Returns zero on success
  */
-int ecryptfs_cipher_code_to_string(char *str, u16 cipher_code)
+int ecryptfs_cipher_code_to_string(char *str, u8 cipher_code)
 {
         int rc = 0;
         int i;
@@ -1236,7 +1236,8 @@ ecryptfs_write_header_metadata(char *virt,
 
         header_extent_size = (u32)crypt_stat->extent_size;
         num_header_extents_at_front =
-                (u16)crypt_stat->num_header_extents_at_front;
+                (u16)(crypt_stat->num_header_bytes_at_front
+                      / crypt_stat->extent_size);
         header_extent_size = cpu_to_be32(header_extent_size);
         memcpy(virt, &header_extent_size, 4);
         virt += 4;
@@ -1311,40 +1312,16 @@ static int ecryptfs_write_headers_virt(char *page_virt, size_t *size,
 static int
 ecryptfs_write_metadata_to_contents(struct ecryptfs_crypt_stat *crypt_stat,
                                     struct dentry *ecryptfs_dentry,
-                                    char *page_virt)
+                                    char *virt)
 {
-        int current_header_page;
-        int header_pages;
         int rc;
 
-        rc = ecryptfs_write_lower(ecryptfs_dentry->d_inode, page_virt,
-                                  0, PAGE_CACHE_SIZE);
-        if (rc) {
+        rc = ecryptfs_write_lower(ecryptfs_dentry->d_inode, virt,
+                                  0, crypt_stat->num_header_bytes_at_front);
+        if (rc)
                 printk(KERN_ERR "%s: Error attempting to write header "
                        "information to lower file; rc = [%d]\n", __FUNCTION__,
                        rc);
-                goto out;
-        }
-        header_pages = ((crypt_stat->extent_size
-                         * crypt_stat->num_header_extents_at_front)
-                        / PAGE_CACHE_SIZE);
-        memset(page_virt, 0, PAGE_CACHE_SIZE);
-        current_header_page = 1;
-        while (current_header_page < header_pages) {
-                loff_t offset;
-
-                offset = (((loff_t)current_header_page) << PAGE_CACHE_SHIFT);
-                if ((rc = ecryptfs_write_lower(ecryptfs_dentry->d_inode,
-                                               page_virt, offset,
-                                               PAGE_CACHE_SIZE))) {
-                        printk(KERN_ERR "%s: Error attempting to write header "
-                               "information to lower file; rc = [%d]\n",
-                               __FUNCTION__, rc);
-                        goto out;
-                }
-                current_header_page++;
-        }
-out:
         return rc;
 }
 
@@ -1370,15 +1347,13 @@ ecryptfs_write_metadata_to_xattr(struct dentry *ecryptfs_dentry,
  * retrieved via a prompt.  Exactly what happens at this point should
  * be policy-dependent.
  *
- * TODO: Support header information spanning multiple pages
- *
  * Returns zero on success; non-zero on error
  */
 int ecryptfs_write_metadata(struct dentry *ecryptfs_dentry)
 {
         struct ecryptfs_crypt_stat *crypt_stat =
                 &ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->crypt_stat;
-        char *page_virt;
+        char *virt;
         size_t size = 0;
         int rc = 0;
 
@@ -1389,40 +1364,39 @@ int ecryptfs_write_metadata(struct dentry *ecryptfs_dentry)
                         goto out;
                 }
         } else {
+                printk(KERN_WARNING "%s: Encrypted flag not set\n",
+                       __FUNCTION__);
                 rc = -EINVAL;
-                ecryptfs_printk(KERN_WARNING,
-                                "Called with crypt_stat->encrypted == 0\n");
                 goto out;
         }
         /* Released in this function */
-        page_virt = kmem_cache_zalloc(ecryptfs_header_cache_0, GFP_USER);
-        if (!page_virt) {
-                ecryptfs_printk(KERN_ERR, "Out of memory\n");
+        virt = kzalloc(crypt_stat->num_header_bytes_at_front, GFP_KERNEL);
+        if (!virt) {
+                printk(KERN_ERR "%s: Out of memory\n", __FUNCTION__);
                 rc = -ENOMEM;
                 goto out;
         }
-        rc = ecryptfs_write_headers_virt(page_virt, &size, crypt_stat,
-                                         ecryptfs_dentry);
+        rc = ecryptfs_write_headers_virt(virt, &size, crypt_stat,
+                                         ecryptfs_dentry);
         if (unlikely(rc)) {
-                ecryptfs_printk(KERN_ERR, "Error whilst writing headers\n");
-                memset(page_virt, 0, PAGE_CACHE_SIZE);
+                printk(KERN_ERR "%s: Error whilst writing headers; rc = [%d]\n",
+                       __FUNCTION__, rc);
                 goto out_free;
         }
         if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR)
                 rc = ecryptfs_write_metadata_to_xattr(ecryptfs_dentry,
-                                                      crypt_stat, page_virt,
-                                                      size);
+                                                      crypt_stat, virt, size);
         else
                 rc = ecryptfs_write_metadata_to_contents(crypt_stat,
-                                                         ecryptfs_dentry,
-                                                         page_virt);
+                                                         ecryptfs_dentry, virt);
         if (rc) {
-                printk(KERN_ERR "Error writing metadata out to lower file; "
-                       "rc = [%d]\n", rc);
+                printk(KERN_ERR "%s: Error writing metadata out to lower file; "
+                       "rc = [%d]\n", __FUNCTION__, rc);
                 goto out_free;
         }
 out_free:
-        kmem_cache_free(ecryptfs_header_cache_0, page_virt);
+        memset(virt, 0, crypt_stat->num_header_bytes_at_front);
+        kfree(virt);
 out:
         return rc;
 }
@@ -1442,16 +1416,16 @@ static int parse_header_metadata(struct ecryptfs_crypt_stat *crypt_stat,
         virt += sizeof(u32);
         memcpy(&num_header_extents_at_front, virt, sizeof(u16));
         num_header_extents_at_front = be16_to_cpu(num_header_extents_at_front);
-        crypt_stat->num_header_extents_at_front =
-                (int)num_header_extents_at_front;
+        crypt_stat->num_header_bytes_at_front =
+                (((size_t)num_header_extents_at_front
+                  * (size_t)header_extent_size));
         (*bytes_read) = (sizeof(u32) + sizeof(u16));
         if ((validate_header_size == ECRYPTFS_VALIDATE_HEADER_SIZE)
-            && ((crypt_stat->extent_size
-                 * crypt_stat->num_header_extents_at_front)
+            && (crypt_stat->num_header_bytes_at_front
                 < ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE)) {
                 rc = -EINVAL;
-                printk(KERN_WARNING "Invalid number of header extents: [%zd]\n",
-                       crypt_stat->num_header_extents_at_front);
+                printk(KERN_WARNING "Invalid header size: [%zd]\n",
+                       crypt_stat->num_header_bytes_at_front);
         }
         return rc;
 }
@@ -1466,7 +1440,8 @@ 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_extents_at_front = 2;
+        crypt_stat->num_header_bytes_at_front =
+                ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE;
 }
 
 /**
@@ -1552,9 +1527,10 @@ int ecryptfs_read_xattr_region(char *page_virt, struct inode *ecryptfs_inode)
         size = ecryptfs_getxattr_lower(lower_dentry, ECRYPTFS_XATTR_NAME,
                                        page_virt, ECRYPTFS_DEFAULT_EXTENT_SIZE);
         if (size < 0) {
-                printk(KERN_ERR "Error attempting to read the [%s] "
-                       "xattr from the lower file; return value = [%zd]\n",
-                       ECRYPTFS_XATTR_NAME, size);
+                if (unlikely(ecryptfs_verbosity > 0))
+                        printk(KERN_INFO "Error attempting to read the [%s] "
+                               "xattr from the lower file; return value = "
+                               "[%zd]\n", ECRYPTFS_XATTR_NAME, size);
                 rc = -EINVAL;
                 goto out;
         }
@@ -1802,7 +1778,7 @@ out:
 }
 
 struct kmem_cache *ecryptfs_key_tfm_cache;
-struct list_head key_tfm_list;
+static struct list_head key_tfm_list;
 struct mutex key_tfm_list_mutex;
 
 int ecryptfs_init_crypto(void)
@@ -1812,6 +1788,11 @@ int ecryptfs_init_crypto(void)
         return 0;
 }
 
+/**
+ * ecryptfs_destroy_crypto - free all cached key_tfms on key_tfm_list
+ *
+ * Called only at module unload time
+ */
 int ecryptfs_destroy_crypto(void)
 {
         struct ecryptfs_key_tfm *key_tfm, *key_tfm_tmp;
@@ -1835,6 +1816,8 @@ ecryptfs_add_new_key_tfm(struct ecryptfs_key_tfm **key_tfm, char *cipher_name,
         struct ecryptfs_key_tfm *tmp_tfm;
         int rc = 0;
 
+        BUG_ON(!mutex_is_locked(&key_tfm_list_mutex));
+
         tmp_tfm = kmem_cache_alloc(ecryptfs_key_tfm_cache, GFP_KERNEL);
         if (key_tfm != NULL)
                 (*key_tfm) = tmp_tfm;
@@ -1861,13 +1844,50 @@ ecryptfs_add_new_key_tfm(struct ecryptfs_key_tfm **key_tfm, char *cipher_name,
                         (*key_tfm) = NULL;
                 goto out;
         }
-        mutex_lock(&key_tfm_list_mutex);
         list_add(&tmp_tfm->key_tfm_list, &key_tfm_list);
-        mutex_unlock(&key_tfm_list_mutex);
 out:
         return rc;
 }
 
+/**
+ * ecryptfs_tfm_exists - Search for existing tfm for cipher_name.
+ * @cipher_name: the name of the cipher to search for
+ * @key_tfm: set to corresponding tfm if found
+ *
+ * Searches for cached key_tfm matching @cipher_name
+ * Must be called with &key_tfm_list_mutex held
+ * Returns 1 if found, with @key_tfm set
+ * Returns 0 if not found, with @key_tfm set to NULL
+ */
+int ecryptfs_tfm_exists(char *cipher_name, struct ecryptfs_key_tfm **key_tfm)
+{
+        struct ecryptfs_key_tfm *tmp_key_tfm;
+
+        BUG_ON(!mutex_is_locked(&key_tfm_list_mutex));
+
+        list_for_each_entry(tmp_key_tfm, &key_tfm_list, key_tfm_list) {
+                if (strcmp(tmp_key_tfm->cipher_name, cipher_name) == 0) {
+                        if (key_tfm)
+                                (*key_tfm) = tmp_key_tfm;
+                        return 1;
+                }
+        }
+        if (key_tfm)
+                (*key_tfm) = NULL;
+        return 0;
+}
+
+/**
+ * ecryptfs_get_tfm_and_mutex_for_cipher_name
+ *
+ * @tfm: set to cached tfm found, or new tfm created
+ * @tfm_mutex: set to mutex for cached tfm found, or new tfm created
+ * @cipher_name: the name of the cipher to search for and/or add
+ *
+ * Sets pointers to @tfm & @tfm_mutex matching @cipher_name.
+ * Searches for cached item first, and creates new if not found.
+ * Returns 0 on success, non-zero if adding new cipher failed
+ */
 int ecryptfs_get_tfm_and_mutex_for_cipher_name(struct crypto_blkcipher **tfm,
                                                struct mutex **tfm_mutex,
                                                char *cipher_name)
@@ -1877,22 +1897,17 @@ int ecryptfs_get_tfm_and_mutex_for_cipher_name(struct crypto_blkcipher **tfm,
 
         (*tfm) = NULL;
         (*tfm_mutex) = NULL;
+
         mutex_lock(&key_tfm_list_mutex);
-        list_for_each_entry(key_tfm, &key_tfm_list, key_tfm_list) {
-                if (strcmp(key_tfm->cipher_name, cipher_name) == 0) {
-                        (*tfm) = key_tfm->key_tfm;
-                        (*tfm_mutex) = &key_tfm->key_tfm_mutex;
-                        mutex_unlock(&key_tfm_list_mutex);
+        if (!ecryptfs_tfm_exists(cipher_name, &key_tfm)) {
+                rc = ecryptfs_add_new_key_tfm(&key_tfm, cipher_name, 0);
+                if (rc) {
+                        printk(KERN_ERR "Error adding new key_tfm to list; "
+                                        "rc = [%d]\n", rc);
                         goto out;
                 }
         }
         mutex_unlock(&key_tfm_list_mutex);
-        rc = ecryptfs_add_new_key_tfm(&key_tfm, cipher_name, 0);
-        if (rc) {
-                printk(KERN_ERR "Error adding new key_tfm to list; rc = [%d]\n",
-                       rc);
-                goto out;
-        }
         (*tfm) = key_tfm->key_tfm;
         (*tfm_mutex) = &key_tfm->key_tfm_mutex;
 out: