eCryptfs: update metadata read/write functions
[safe/jmp/linux-2.6] / fs / ecryptfs / crypto.c
index 7f788ea..55110ff 100644 (file)
@@ -1342,21 +1342,28 @@ out:
        return rc;
 }
 
-int ecryptfs_read_and_validate_header_region(char *data, struct dentry *dentry,
-                                            struct vfsmount *mnt)
+int ecryptfs_read_and_validate_header_region(char *data,
+                                            struct inode *ecryptfs_inode)
 {
+       struct ecryptfs_crypt_stat *crypt_stat =
+               &(ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat);
        int rc;
 
-       rc = ecryptfs_read_header_region(data, dentry, mnt);
-       if (rc)
+       rc = ecryptfs_read_lower(data, 0, crypt_stat->extent_size,
+                                ecryptfs_inode);
+       if (rc) {
+               printk(KERN_ERR "%s: Error reading header region; rc = [%d]\n",
+                      __FUNCTION__, rc);
                goto out;
-       if (!contains_ecryptfs_marker(data + ECRYPTFS_FILE_SIZE_BYTES))
+       }
+       if (!contains_ecryptfs_marker(data + ECRYPTFS_FILE_SIZE_BYTES)) {
                rc = -EINVAL;
+               ecryptfs_printk(KERN_DEBUG, "Valid marker not found\n");
+       }
 out:
        return rc;
 }
 
-
 void
 ecryptfs_write_header_metadata(char *virt,
                               struct ecryptfs_crypt_stat *crypt_stat,
@@ -1441,24 +1448,19 @@ 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 file *lower_file, char *page_virt)
+                                   struct dentry *ecryptfs_dentry,
+                                   char *page_virt)
 {
-       mm_segment_t oldfs;
        int current_header_page;
        int header_pages;
-       ssize_t size;
-       int rc = 0;
+       int rc;
 
-       lower_file->f_pos = 0;
-       oldfs = get_fs();
-       set_fs(get_ds());
-       size = vfs_write(lower_file, (char __user *)page_virt, PAGE_CACHE_SIZE,
-                        &lower_file->f_pos);
-       if (size < 0) {
-               rc = (int)size;
-               printk(KERN_ERR "Error attempting to write lower page; "
-                      "rc = [%d]\n", rc);
-               set_fs(oldfs);
+       rc = ecryptfs_write_lower(ecryptfs_dentry->d_inode, page_virt,
+                                 0, PAGE_CACHE_SIZE);
+       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
@@ -1467,18 +1469,19 @@ ecryptfs_write_metadata_to_contents(struct ecryptfs_crypt_stat *crypt_stat,
        memset(page_virt, 0, PAGE_CACHE_SIZE);
        current_header_page = 1;
        while (current_header_page < header_pages) {
-               size = vfs_write(lower_file, (char __user *)page_virt,
-                                PAGE_CACHE_SIZE, &lower_file->f_pos);
-               if (size < 0) {
-                       rc = (int)size;
-                       printk(KERN_ERR "Error attempting to write lower page; "
-                              "rc = [%d]\n", rc);
-                       set_fs(oldfs);
+               loff_t offset;
+
+               offset = (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++;
        }
-       set_fs(oldfs);
 out:
        return rc;
 }
@@ -1498,7 +1501,6 @@ ecryptfs_write_metadata_to_xattr(struct dentry *ecryptfs_dentry,
 /**
  * ecryptfs_write_metadata
  * @ecryptfs_dentry: The eCryptfs dentry
- * @lower_file: The lower file struct, which was returned from dentry_open
  *
  * Write the file headers out.  This will likely involve a userspace
  * callout, in which the session key is encrypted with one or more
@@ -1506,22 +1508,21 @@ 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 file *lower_file)
+int ecryptfs_write_metadata(struct dentry *ecryptfs_dentry)
 {
-       struct ecryptfs_crypt_stat *crypt_stat;
+       struct ecryptfs_crypt_stat *crypt_stat =
+               &ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->crypt_stat;
        char *page_virt;
-       size_t size;
+       size_t size = 0;
        int rc = 0;
 
-       crypt_stat = &ecryptfs_inode_to_private(
-               ecryptfs_dentry->d_inode)->crypt_stat;
        if (likely(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
                if (!(crypt_stat->flags & ECRYPTFS_KEY_VALID)) {
-                       ecryptfs_printk(KERN_DEBUG, "Key is "
-                                       "invalid; bailing out\n");
+                       printk(KERN_ERR "Key is invalid; bailing out\n");
                        rc = -EINVAL;
                        goto out;
                }
@@ -1550,7 +1551,8 @@ int ecryptfs_write_metadata(struct dentry *ecryptfs_dentry,
                                                      crypt_stat, page_virt,
                                                      size);
        else
-               rc = ecryptfs_write_metadata_to_contents(crypt_stat, lower_file,
+               rc = ecryptfs_write_metadata_to_contents(crypt_stat,
+                                                        ecryptfs_dentry,
                                                         page_virt);
        if (rc) {
                printk(KERN_ERR "Error writing metadata out to lower file; "
@@ -1678,15 +1680,17 @@ out:
  *
  * Returns zero on success; non-zero on error
  */
-int ecryptfs_read_xattr_region(char *page_virt, struct dentry *ecryptfs_dentry)
+int ecryptfs_read_xattr_region(char *page_virt, struct inode *ecryptfs_inode)
 {
+       struct dentry *lower_dentry =
+               ecryptfs_inode_to_private(ecryptfs_inode)->lower_file->f_dentry;
        ssize_t size;
        int rc = 0;
 
-       size = ecryptfs_getxattr(ecryptfs_dentry, ECRYPTFS_XATTR_NAME,
-                                page_virt, ECRYPTFS_DEFAULT_EXTENT_SIZE);
+       size = ecryptfs_getxattr_lower(lower_dentry, ECRYPTFS_XATTR_NAME,
+                                      page_virt, ECRYPTFS_DEFAULT_EXTENT_SIZE);
        if (size < 0) {
-               printk(KERN_DEBUG "Error attempting to read the [%s] "
+               printk(KERN_ERR "Error attempting to read the [%s] "
                       "xattr from the lower file; return value = [%zd]\n",
                       ECRYPTFS_XATTR_NAME, size);
                rc = -EINVAL;
@@ -1701,7 +1705,7 @@ int ecryptfs_read_and_validate_xattr_region(char *page_virt,
 {
        int rc;
 
-       rc = ecryptfs_read_xattr_region(page_virt, ecryptfs_dentry);
+       rc = ecryptfs_read_xattr_region(page_virt, ecryptfs_dentry->d_inode);
        if (rc)
                goto out;
        if (!contains_ecryptfs_marker(page_virt + ECRYPTFS_FILE_SIZE_BYTES)) {
@@ -1715,8 +1719,6 @@ out:
 
 /**
  * ecryptfs_read_metadata
- * @ecryptfs_dentry: The eCryptfs dentry
- * @lower_file: The lower file from which to read the metadata
  *
  * Common entry point for reading file metadata. From here, we could
  * retrieve the header information from the header region of the file,
@@ -1727,15 +1729,13 @@ out:
  *
  * Returns zero if valid headers found and parsed; non-zero otherwise
  */
-int ecryptfs_read_metadata(struct dentry *ecryptfs_dentry,
-                          struct file *lower_file)
+int ecryptfs_read_metadata(struct dentry *ecryptfs_dentry)
 {
        int rc = 0;
        char *page_virt = NULL;
-       mm_segment_t oldfs;
-       ssize_t bytes_read;
+       struct inode *ecryptfs_inode = ecryptfs_dentry->d_inode;
        struct ecryptfs_crypt_stat *crypt_stat =
-           &ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->crypt_stat;
+           &ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat;
        struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
                &ecryptfs_superblock_to_private(
                        ecryptfs_dentry->d_sb)->mount_crypt_stat;
@@ -1746,27 +1746,18 @@ int ecryptfs_read_metadata(struct dentry *ecryptfs_dentry,
        page_virt = kmem_cache_alloc(ecryptfs_header_cache_1, GFP_USER);
        if (!page_virt) {
                rc = -ENOMEM;
-               ecryptfs_printk(KERN_ERR, "Unable to allocate page_virt\n");
+               printk(KERN_ERR "%s: Unable to allocate page_virt\n",
+                      __FUNCTION__);
                goto out;
        }
-       lower_file->f_pos = 0;
-       oldfs = get_fs();
-       set_fs(get_ds());
-       bytes_read = lower_file->f_op->read(lower_file,
-                                           (char __user *)page_virt,
-                                           ECRYPTFS_DEFAULT_EXTENT_SIZE,
-                                           &lower_file->f_pos);
-       set_fs(oldfs);
-       if (bytes_read != ECRYPTFS_DEFAULT_EXTENT_SIZE) {
-               rc = -EINVAL;
-               goto out;
-       }
-       rc = ecryptfs_read_headers_virt(page_virt, crypt_stat,
-                                       ecryptfs_dentry,
-                                       ECRYPTFS_VALIDATE_HEADER_SIZE);
+       rc = ecryptfs_read_lower(page_virt, 0, crypt_stat->extent_size,
+                                ecryptfs_inode);
+       if (!rc)
+               rc = ecryptfs_read_headers_virt(page_virt, crypt_stat,
+                                               ecryptfs_dentry,
+                                               ECRYPTFS_VALIDATE_HEADER_SIZE);
        if (rc) {
-               rc = ecryptfs_read_xattr_region(page_virt,
-                                               ecryptfs_dentry);
+               rc = ecryptfs_read_xattr_region(page_virt, ecryptfs_inode);
                if (rc) {
                        printk(KERN_DEBUG "Valid eCryptfs headers not found in "
                               "file header region or xattr region\n");