1 files changed, 199 insertions, 179 deletions

diff --git a/fs/ecryptfs/mmap.c b/fs/ecryptfs/mmap.c
index 06843d24f239..3a6f65c3f14f 100644
--- a/fs/ecryptfs/mmap.c
+++ b/fs/ecryptfs/mmap.c
@@ -6,7 +6,7 @@
  *
  * Copyright (C) 1997-2003 Erez Zadok
  * Copyright (C) 2001-2003 Stony Brook University
- * Copyright (C) 2004-2006 International Business Machines Corp.
+ * Copyright (C) 2004-2007 International Business Machines Corp.
  *   Author(s): Michael A. Halcrow <mahalcro@us.ibm.com>
  *
  * This program is free software; you can redistribute it and/or
@@ -234,22 +234,13 @@ int ecryptfs_do_readpage(struct file *file, struct page *page,
                 goto out;
         }
         wait_on_page_locked(lower_page);
-        page_data = (char *)kmap(page);
-        if (!page_data) {
-                rc = -ENOMEM;
-                ecryptfs_printk(KERN_ERR, "Error mapping page\n");
-                goto out;
-        }
-        lower_page_data = (char *)kmap(lower_page);
-        if (!lower_page_data) {
-                rc = -ENOMEM;
-                ecryptfs_printk(KERN_ERR, "Error mapping page\n");
-                kunmap(page);
-                goto out;
-        }
+        page_data = kmap_atomic(page, KM_USER0);
+        lower_page_data = kmap_atomic(lower_page, KM_USER1);
         memcpy(page_data, lower_page_data, PAGE_CACHE_SIZE);
-        kunmap(lower_page);
-        kunmap(page);
+        kunmap_atomic(lower_page_data, KM_USER1);
+        flush_dcache_page(lower_page);
+        kunmap_atomic(page_data, KM_USER0);
+        flush_dcache_page(page);
         rc = 0;
 out:
         if (likely(lower_page))
@@ -260,6 +251,33 @@ out:
                 ClearPageUptodate(page);
         return rc;
 }
+/**
+ *   Header Extent:
+ *     Octets 0-7:        Unencrypted file size (big-endian)
+ *     Octets 8-15:       eCryptfs special marker
+ *     Octets 16-19:      Flags
+ *      Octet 16:         File format version number (between 0 and 255)
+ *      Octets 17-18:     Reserved
+ *      Octet 19:         Bit 1 (lsb): Reserved
+ *                        Bit 2: Encrypted?
+ *                        Bits 3-8: Reserved
+ *     Octets 20-23:      Header extent size (big-endian)
+ *     Octets 24-25:      Number of header extents at front of file
+ *                        (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;
+        int save_num_header_extents_at_front =
+                crypt_stat->num_header_extents_at_front;
+
+        crypt_stat->num_header_extents_at_front = 1;
+        ecryptfs_write_header_metadata(page_virt + 20, crypt_stat, &written);
+        crypt_stat->num_header_extents_at_front =
+                save_num_header_extents_at_front;
+}
 
 /**
  * ecryptfs_readpage
@@ -279,8 +297,8 @@ static int ecryptfs_readpage(struct file *file, struct page *page)
         crypt_stat = &ecryptfs_inode_to_private(file->f_path.dentry->d_inode)
                         ->crypt_stat;
         if (!crypt_stat
-            || !ECRYPTFS_CHECK_FLAG(crypt_stat->flags, ECRYPTFS_ENCRYPTED)
-            || ECRYPTFS_CHECK_FLAG(crypt_stat->flags, ECRYPTFS_NEW_FILE)) {
+            || !(crypt_stat->flags & ECRYPTFS_ENCRYPTED)
+            || (crypt_stat->flags & ECRYPTFS_NEW_FILE)) {
                 ecryptfs_printk(KERN_DEBUG,
                                 "Passing through unencrypted page\n");
                 rc = ecryptfs_do_readpage(file, page, page->index);
@@ -289,10 +307,51 @@ static int ecryptfs_readpage(struct file *file, struct page *page)
                                         "[%d]\n", rc);
                         goto out;
                 }
+        } else if (crypt_stat->flags & ECRYPTFS_VIEW_AS_ENCRYPTED) {
+                if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) {
+                        int num_pages_in_header_region =
+                                (crypt_stat->header_extent_size
+                                 / PAGE_CACHE_SIZE);
+
+                        if (page->index < num_pages_in_header_region) {
+                                char *page_virt;
+
+                                page_virt = kmap_atomic(page, KM_USER0);
+                                memset(page_virt, 0, PAGE_CACHE_SIZE);
+                                if (page->index == 0) {
+                                        rc = ecryptfs_read_xattr_region(
+                                                page_virt, file->f_path.dentry);
+                                        set_header_info(page_virt, crypt_stat);
+                                }
+                                kunmap_atomic(page_virt, KM_USER0);
+                                flush_dcache_page(page);
+                                if (rc) {
+                                        printk(KERN_ERR "Error reading xattr "
+                                               "region\n");
+                                        goto out;
+                                }
+                        } else {
+                                rc = ecryptfs_do_readpage(
+                                        file, page,
+                                        (page->index
+                                         - num_pages_in_header_region));
+                                if (rc) {
+                                        printk(KERN_ERR "Error reading page; "
+                                               "rc = [%d]\n", rc);
+                                        goto out;
+                                }
+                        }
+                } else {
+                        rc = ecryptfs_do_readpage(file, page, page->index);
+                        if (rc) {
+                                printk(KERN_ERR "Error reading page; rc = "
+                                       "[%d]\n", rc);
+                                goto out;
+                        }
+                }
         } else {
                 rc = ecryptfs_decrypt_page(file, page);
                 if (rc) {
-
                         ecryptfs_printk(KERN_ERR, "Error decrypting page; "
                                         "rc = [%d]\n", rc);
                         goto out;
@@ -308,30 +367,27 @@ out:
         return rc;
 }
 
+/**
+ * Called with lower inode mutex held.
+ */
 static int fill_zeros_to_end_of_page(struct page *page, unsigned int to)
 {
         struct inode *inode = page->mapping->host;
         int end_byte_in_page;
-        int rc = 0;
         char *page_virt;
 
-        if ((i_size_read(inode) / PAGE_CACHE_SIZE) == page->index) {
-                end_byte_in_page = i_size_read(inode) % PAGE_CACHE_SIZE;
-                if (to > end_byte_in_page)
-                        end_byte_in_page = to;
-                page_virt = kmap(page);
-                if (!page_virt) {
-                        rc = -ENOMEM;
-                        ecryptfs_printk(KERN_WARNING,
-                                        "Could not map page\n");
-                        goto out;
-                }
-                memset((page_virt + end_byte_in_page), 0,
-                       (PAGE_CACHE_SIZE - end_byte_in_page));
-                kunmap(page);
-        }
+        if ((i_size_read(inode) / PAGE_CACHE_SIZE) != page->index)
+                goto out;
+        end_byte_in_page = i_size_read(inode) % PAGE_CACHE_SIZE;
+        if (to > end_byte_in_page)
+                end_byte_in_page = to;
+        page_virt = kmap_atomic(page, KM_USER0);
+        memset((page_virt + end_byte_in_page), 0,
+               (PAGE_CACHE_SIZE - end_byte_in_page));
+        kunmap_atomic(page_virt, KM_USER0);
+        flush_dcache_page(page);
 out:
-        return rc;
+        return 0;
 }
 
 static int ecryptfs_prepare_write(struct file *file, struct page *page,
@@ -339,7 +395,6 @@ static int ecryptfs_prepare_write(struct file *file, struct page *page,
 {
         int rc = 0;
 
-        kmap(page);
         if (from == 0 && to == PAGE_CACHE_SIZE)
                 goto out;       /* If we are writing a full page, it will be
                                    up to date. */
@@ -349,30 +404,6 @@ out:
         return rc;
 }
 
-int ecryptfs_grab_and_map_lower_page(struct page **lower_page,
-                                     char **lower_virt,
-                                     struct inode *lower_inode,
-                                     unsigned long lower_page_index)
-{
-        int rc = 0;
-
-        (*lower_page) = grab_cache_page(lower_inode->i_mapping,
-                                        lower_page_index);
-        if (!(*lower_page)) {
-                ecryptfs_printk(KERN_ERR, "grab_cache_page for "
-                                "lower_page_index = [0x%.16x] failed\n",
-                                lower_page_index);
-                rc = -EINVAL;
-                goto out;
-        }
-        if (lower_virt)
-                (*lower_virt) = kmap((*lower_page));
-        else
-                kmap((*lower_page));
-out:
-        return rc;
-}
-
 int ecryptfs_writepage_and_release_lower_page(struct page *lower_page,
                                               struct inode *lower_inode,
                                               struct writeback_control *wbc)
@@ -391,11 +422,8 @@ out:
         return rc;
 }
 
-static void ecryptfs_unmap_and_release_lower_page(struct page *lower_page)
+static void ecryptfs_release_lower_page(struct page *lower_page)
 {
-        kunmap(lower_page);
-        ecryptfs_printk(KERN_DEBUG, "Unlocking lower page with index = "
-                        "[0x%.16x]\n", lower_page->index);
         unlock_page(lower_page);
         page_cache_release(lower_page);
 }
@@ -407,10 +435,9 @@ static void ecryptfs_unmap_and_release_lower_page(struct page *lower_page)
  *
  * Returns zero on success; non-zero on error.
  */
-int
-ecryptfs_write_inode_size_to_header(struct file *lower_file,
-                                    struct inode *lower_inode,
-                                    struct inode *inode)
+static int ecryptfs_write_inode_size_to_header(struct file *lower_file,
+                                               struct inode *lower_inode,
+                                               struct inode *inode)
 {
         int rc = 0;
         struct page *header_page;
@@ -418,11 +445,11 @@ ecryptfs_write_inode_size_to_header(struct file *lower_file,
         const struct address_space_operations *lower_a_ops;
         u64 file_size;
 
-        rc = ecryptfs_grab_and_map_lower_page(&header_page, &header_virt,
-                                              lower_inode, 0);
-        if (rc) {
-                ecryptfs_printk(KERN_ERR, "grab_cache_page for header page "
-                                "failed\n");
+        header_page = grab_cache_page(lower_inode->i_mapping, 0);
+        if (!header_page) {
+                ecryptfs_printk(KERN_ERR, "grab_cache_page for "
+                                "lower_page_index 0 failed\n");
+                rc = -EINVAL;
                 goto out;
         }
         lower_a_ops = lower_inode->i_mapping->a_ops;
@@ -430,18 +457,95 @@ ecryptfs_write_inode_size_to_header(struct file *lower_file,
         file_size = (u64)i_size_read(inode);
         ecryptfs_printk(KERN_DEBUG, "Writing size: [0x%.16x]\n", file_size);
         file_size = cpu_to_be64(file_size);
+        header_virt = kmap_atomic(header_page, KM_USER0);
         memcpy(header_virt, &file_size, sizeof(u64));
+        kunmap_atomic(header_virt, KM_USER0);
+        flush_dcache_page(header_page);
         rc = lower_a_ops->commit_write(lower_file, header_page, 0, 8);
         if (rc < 0)
                 ecryptfs_printk(KERN_ERR, "Error commiting header page "
                                 "write\n");
-        ecryptfs_unmap_and_release_lower_page(header_page);
+        ecryptfs_release_lower_page(header_page);
         lower_inode->i_mtime = lower_inode->i_ctime = CURRENT_TIME;
         mark_inode_dirty_sync(inode);
 out:
         return rc;
 }
 
+static int ecryptfs_write_inode_size_to_xattr(struct inode *lower_inode,
+                                              struct inode *inode,
+                                              struct dentry *ecryptfs_dentry,
+                                              int lower_i_mutex_held)
+{
+        ssize_t size;
+        void *xattr_virt;
+        struct dentry *lower_dentry;
+        u64 file_size;
+        int rc;
+
+        xattr_virt = kmem_cache_alloc(ecryptfs_xattr_cache, GFP_KERNEL);
+        if (!xattr_virt) {
+                printk(KERN_ERR "Out of memory whilst attempting to write "
+                       "inode size to xattr\n");
+                rc = -ENOMEM;
+                goto out;
+        }
+        lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
+        if (!lower_dentry->d_inode->i_op->getxattr) {
+                printk(KERN_WARNING
+                       "No support for setting xattr in lower filesystem\n");
+                rc = -ENOSYS;
+                kmem_cache_free(ecryptfs_xattr_cache, xattr_virt);
+                goto out;
+        }
+        if (!lower_i_mutex_held)
+                mutex_lock(&lower_dentry->d_inode->i_mutex);
+        size = lower_dentry->d_inode->i_op->getxattr(lower_dentry,
+                                                     ECRYPTFS_XATTR_NAME,
+                                                     xattr_virt,
+                                                     PAGE_CACHE_SIZE);
+        if (!lower_i_mutex_held)
+                mutex_unlock(&lower_dentry->d_inode->i_mutex);
+        if (size < 0)
+                size = 8;
+        file_size = (u64)i_size_read(inode);
+        file_size = cpu_to_be64(file_size);
+        memcpy(xattr_virt, &file_size, sizeof(u64));
+        if (!lower_i_mutex_held)
+                mutex_lock(&lower_dentry->d_inode->i_mutex);
+        rc = lower_dentry->d_inode->i_op->setxattr(lower_dentry,
+                                                   ECRYPTFS_XATTR_NAME,
+                                                   xattr_virt, size, 0);
+        if (!lower_i_mutex_held)
+                mutex_unlock(&lower_dentry->d_inode->i_mutex);
+        if (rc)
+                printk(KERN_ERR "Error whilst attempting to write inode size "
+                       "to lower file xattr; rc = [%d]\n", rc);
+        kmem_cache_free(ecryptfs_xattr_cache, xattr_virt);
+out:
+        return rc;
+}
+
+int
+ecryptfs_write_inode_size_to_metadata(struct file *lower_file,
+                                      struct inode *lower_inode,
+                                      struct inode *inode,
+                                      struct dentry *ecryptfs_dentry,
+                                      int lower_i_mutex_held)
+{
+        struct ecryptfs_crypt_stat *crypt_stat;
+
+        crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
+        if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR)
+                return ecryptfs_write_inode_size_to_xattr(lower_inode, inode,
+                                                          ecryptfs_dentry,
+                                                          lower_i_mutex_held);
+        else
+                return ecryptfs_write_inode_size_to_header(lower_file,
+                                                           lower_inode,
+                                                           inode);
+}
+
 int ecryptfs_get_lower_page(struct page **lower_page, struct inode *lower_inode,
                             struct file *lower_file,
                             unsigned long lower_page_index, int byte_offset,
@@ -449,10 +553,10 @@ int ecryptfs_get_lower_page(struct page **lower_page, struct inode *lower_inode,
 {
         int rc = 0;
 
-        rc = ecryptfs_grab_and_map_lower_page(lower_page, NULL, lower_inode,
-                                              lower_page_index);
-        if (rc) {
-                ecryptfs_printk(KERN_ERR, "Error attempting to grab and map "
+        *lower_page = grab_cache_page(lower_inode->i_mapping, lower_page_index);
+        if (!(*lower_page)) {
+                rc = -EINVAL;
+                ecryptfs_printk(KERN_ERR, "Error attempting to grab "
                                 "lower page with index [0x%.16x]\n",
                                 lower_page_index);
                 goto out;
@@ -468,7 +572,7 @@ int ecryptfs_get_lower_page(struct page **lower_page, struct inode *lower_inode,
         }
 out:
         if (rc && (*lower_page)) {
-                ecryptfs_unmap_and_release_lower_page(*lower_page);
+                ecryptfs_release_lower_page(*lower_page);
                 (*lower_page) = NULL;
         }
         return rc;
@@ -493,7 +597,7 @@ ecryptfs_commit_lower_page(struct page *lower_page, struct inode *lower_inode,
                                 "Error committing write; rc = [%d]\n", rc);
         } else
                 rc = 0;
-        ecryptfs_unmap_and_release_lower_page(lower_page);
+        ecryptfs_release_lower_page(lower_page);
         return rc;
 }
 
@@ -528,89 +632,7 @@ out:
         return rc;
 }
 
-static int
-process_new_file(struct ecryptfs_crypt_stat *crypt_stat,
-                 struct file *file, struct inode *inode)
-{
-        struct page *header_page;
-        const struct address_space_operations *lower_a_ops;
-        struct inode *lower_inode;
-        struct file *lower_file;
-        char *header_virt;
-        int rc = 0;
-        int current_header_page = 0;
-        int header_pages;
-        int more_header_data_to_be_written = 1;
-
-        lower_inode = ecryptfs_inode_to_lower(inode);
-        lower_file = ecryptfs_file_to_lower(file);
-        lower_a_ops = lower_inode->i_mapping->a_ops;
-        header_pages = ((crypt_stat->header_extent_size
-                         * crypt_stat->num_header_extents_at_front)
-                        / PAGE_CACHE_SIZE);
-        BUG_ON(header_pages < 1);
-        while (current_header_page < header_pages) {
-                rc = ecryptfs_grab_and_map_lower_page(&header_page,
-                                                      &header_virt,
-                                                      lower_inode,
-                                                      current_header_page);
-                if (rc) {
-                        ecryptfs_printk(KERN_ERR, "grab_cache_page for "
-                                        "header page [%d] failed; rc = [%d]\n",
-                                        current_header_page, rc);
-                        goto out;
-                }
-                rc = lower_a_ops->prepare_write(lower_file, header_page, 0,
-                                                PAGE_CACHE_SIZE);
-                if (rc) {
-                        ecryptfs_printk(KERN_ERR, "Error preparing to write "
-                                        "header page out; rc = [%d]\n", rc);
-                        goto out;
-                }
-                memset(header_virt, 0, PAGE_CACHE_SIZE);
-                if (more_header_data_to_be_written) {
-                        rc = ecryptfs_write_headers_virt(header_virt,
-                                                         crypt_stat,
-                                                         file->f_dentry);
-                        if (rc) {
-                                ecryptfs_printk(KERN_WARNING, "Error "
-                                                "generating header; rc = "
-                                                "[%d]\n", rc);
-                                rc = -EIO;
-                                memset(header_virt, 0, PAGE_CACHE_SIZE);
-                                ecryptfs_unmap_and_release_lower_page(
-                                        header_page);
-                                goto out;
-                        }
-                        if (current_header_page == 0)
-                                memset(header_virt, 0, 8);
-                        more_header_data_to_be_written = 0;
-                }
-                rc = lower_a_ops->commit_write(lower_file, header_page, 0,
-                                               PAGE_CACHE_SIZE);
-                ecryptfs_unmap_and_release_lower_page(header_page);
-                if (rc < 0) {
-                        ecryptfs_printk(KERN_ERR,
-                                        "Error commiting header page write; "
-                                        "rc = [%d]\n", rc);
-                        break;
-                }
-                current_header_page++;
-        }
-        if (rc >= 0) {
-                rc = 0;
-                ecryptfs_printk(KERN_DEBUG, "lower_inode->i_blocks = "
-                                "[0x%.16x]\n", lower_inode->i_blocks);
-                i_size_write(inode, 0);
-                lower_inode->i_mtime = lower_inode->i_ctime = CURRENT_TIME;
-                mark_inode_dirty_sync(inode);
-        }
-        ecryptfs_printk(KERN_DEBUG, "Clearing ECRYPTFS_NEW_FILE flag in "
-                        "crypt_stat at memory location [%p]\n", crypt_stat);
-        ECRYPTFS_CLEAR_FLAG(crypt_stat->flags, ECRYPTFS_NEW_FILE);
-out:
-        return rc;
-}
+struct kmem_cache *ecryptfs_xattr_cache;
 
 /**
  * ecryptfs_commit_write
@@ -640,15 +662,10 @@ static int ecryptfs_commit_write(struct file *file, struct page *page,
         mutex_lock(&lower_inode->i_mutex);
         crypt_stat = &ecryptfs_inode_to_private(file->f_path.dentry->d_inode)
                                 ->crypt_stat;
-        if (ECRYPTFS_CHECK_FLAG(crypt_stat->flags, ECRYPTFS_NEW_FILE)) {
+        if (crypt_stat->flags & ECRYPTFS_NEW_FILE) {
                 ecryptfs_printk(KERN_DEBUG, "ECRYPTFS_NEW_FILE flag set in "
                         "crypt_stat at memory location [%p]\n", crypt_stat);
-                rc = process_new_file(crypt_stat, file, inode);
-                if (rc) {
-                        ecryptfs_printk(KERN_ERR, "Error processing new "
-                                        "file; rc = [%d]\n", rc);
-                        goto out;
-                }
+                crypt_stat->flags &= ~(ECRYPTFS_NEW_FILE);
         } else
                 ecryptfs_printk(KERN_DEBUG, "Not a new file\n");
         ecryptfs_printk(KERN_DEBUG, "Calling fill_zeros_to_end_of_page"
@@ -670,7 +687,6 @@ static int ecryptfs_commit_write(struct file *file, struct page *page,
                                 "index [0x%.16x])\n", page->index);
                 goto out;
         }
-        rc = 0;
         inode->i_blocks = lower_inode->i_blocks;
         pos = (page->index << PAGE_CACHE_SHIFT) + to;
         if (pos > i_size_read(inode)) {
@@ -678,11 +694,15 @@ static int ecryptfs_commit_write(struct file *file, struct page *page,
                 ecryptfs_printk(KERN_DEBUG, "Expanded file size to "
                                 "[0x%.16x]\n", i_size_read(inode));
         }
-        ecryptfs_write_inode_size_to_header(lower_file, lower_inode, inode);
+        rc = ecryptfs_write_inode_size_to_metadata(lower_file, lower_inode,
+                                                   inode, file->f_dentry,
+                                                   ECRYPTFS_LOWER_I_MUTEX_HELD);
+        if (rc)
+                printk(KERN_ERR "Error writing inode size to metadata; "
+                       "rc = [%d]\n", rc);
         lower_inode->i_mtime = lower_inode->i_ctime = CURRENT_TIME;
         mark_inode_dirty_sync(inode);
 out:
-        kunmap(page); /* mapped in prior call (prepare_write) */
         if (rc < 0)
                 ClearPageUptodate(page);
         else
@@ -707,6 +727,7 @@ int write_zeros(struct file *file, pgoff_t index, int start, int num_zeros)
 {
         int rc = 0;
         struct page *tmp_page;
+        char *tmp_page_virt;
 
         tmp_page = ecryptfs_get1page(file, index);
         if (IS_ERR(tmp_page)) {
@@ -715,28 +736,27 @@ int write_zeros(struct file *file, pgoff_t index, int start, int num_zeros)
                 rc = PTR_ERR(tmp_page);
                 goto out;
         }
-        kmap(tmp_page);
         rc = ecryptfs_prepare_write(file, tmp_page, start, start + num_zeros);
         if (rc) {
                 ecryptfs_printk(KERN_ERR, "Error preparing to write zero's "
                                 "to remainder of page at index [0x%.16x]\n",
                                 index);
-                kunmap(tmp_page);
                 page_cache_release(tmp_page);
                 goto out;
         }
-        memset(((char *)page_address(tmp_page) + start), 0, num_zeros);
+        tmp_page_virt = kmap_atomic(tmp_page, KM_USER0);
+        memset(((char *)tmp_page_virt + start), 0, num_zeros);
+        kunmap_atomic(tmp_page_virt, KM_USER0);
+        flush_dcache_page(tmp_page);
         rc = ecryptfs_commit_write(file, tmp_page, start, start + num_zeros);
         if (rc < 0) {
                 ecryptfs_printk(KERN_ERR, "Error attempting to write zero's "
                                 "to remainder of page at index [0x%.16x]\n",
                                 index);
-                kunmap(tmp_page);
                 page_cache_release(tmp_page);
                 goto out;
         }
         rc = 0;
-        kunmap(tmp_page);
         page_cache_release(tmp_page);
 out:
         return rc;