Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

[linux-2.6] / fs / ecryptfs / read_write.c

diff --git a/fs/ecryptfs/read_write.c b/fs/ecryptfs/read_write.c
index ccd2599e0a4fa12f35938379b901f202c1c5f56f..948f57624c05dd2bb1750ff05628f7931f44f2b7 100644 (file)
--- a/fs/ecryptfs/read_write.c
+++ b/fs/ecryptfs/read_write.c
@@ -87,7 +87,8 @@ int ecryptfs_write_lower_page_segment(struct inode *ecryptfs_inode,
        loff_t offset;
        int rc;
 
-       offset = (page_for_lower->index << PAGE_CACHE_SHIFT) + offset_in_page;
+       offset = ((((loff_t)page_for_lower->index) << PAGE_CACHE_SHIFT)
+                 + offset_in_page);
        virt = kmap(page_for_lower);
        rc = ecryptfs_write_lower(ecryptfs_inode, virt, offset, size);
        kunmap(page_for_lower);
@@ -117,11 +118,16 @@ int ecryptfs_write(struct file *ecryptfs_file, char *data, loff_t offset,
 {
        struct page *ecryptfs_page;
        char *ecryptfs_page_virt;
-       u64 ecryptfs_file_size = i_size_read(ecryptfs_file->f_dentry->d_inode);
+       loff_t ecryptfs_file_size =
+               i_size_read(ecryptfs_file->f_dentry->d_inode);
        loff_t data_offset = 0;
        loff_t pos;
        int rc = 0;
 
+       /*
+        * if we are writing beyond current size, then start pos
+        * at the current size - we'll fill in zeros from there.
+        */
        if (offset > ecryptfs_file_size)
                pos = ecryptfs_file_size;
        else
@@ -135,13 +141,14 @@ int ecryptfs_write(struct file *ecryptfs_file, char *data, loff_t offset,
                if (num_bytes > total_remaining_bytes)
                        num_bytes = total_remaining_bytes;
                if (pos < offset) {
+                       /* remaining zeros to write, up to destination offset */
                        size_t total_remaining_zeros = (offset - pos);
 
                        if (num_bytes > total_remaining_zeros)
                                num_bytes = total_remaining_zeros;
                }
-               ecryptfs_page = ecryptfs_get1page(ecryptfs_file,
-                                                 ecryptfs_page_idx);
+               ecryptfs_page = ecryptfs_get_locked_page(ecryptfs_file,
+                                                        ecryptfs_page_idx);
                if (IS_ERR(ecryptfs_page)) {
                        rc = PTR_ERR(ecryptfs_page);
                        printk(KERN_ERR "%s: Error getting page at "
@@ -159,33 +166,45 @@ int ecryptfs_write(struct file *ecryptfs_file, char *data, loff_t offset,
                                printk(KERN_ERR "%s: Error decrypting "
                                       "page; rc = [%d]\n",
                                       __FUNCTION__, rc);
+                               ClearPageUptodate(ecryptfs_page);
                                page_cache_release(ecryptfs_page);
                                goto out;
                        }
                }
                ecryptfs_page_virt = kmap_atomic(ecryptfs_page, KM_USER0);
+
+               /*
+                * pos: where we're now writing, offset: where the request was
+                * If current pos is before request, we are filling zeros
+                * If we are at or beyond request, we are writing the *data*
+                * If we're in a fresh page beyond eof, zero it in either case
+                */
+               if (pos < offset || !start_offset_in_page) {
+                       /* We are extending past the previous end of the file.
+                        * Fill in zero values to the end of the page */
+                       memset(((char *)ecryptfs_page_virt
+                               + start_offset_in_page), 0,
+                               PAGE_CACHE_SIZE - start_offset_in_page);
+               }
+
+               /* pos >= offset, we are now writing the data request */
                if (pos >= offset) {
                        memcpy(((char *)ecryptfs_page_virt
                                + start_offset_in_page),
                               (data + data_offset), num_bytes);
                        data_offset += num_bytes;
-               } else {
-                       /* We are extending past the previous end of the file.
-                        * Fill in zero values up to the start of where we
-                        * will be writing data. */
-                       memset(((char *)ecryptfs_page_virt
-                               + start_offset_in_page), 0, num_bytes);
                }
                kunmap_atomic(ecryptfs_page_virt, KM_USER0);
                flush_dcache_page(ecryptfs_page);
+               SetPageUptodate(ecryptfs_page);
+               unlock_page(ecryptfs_page);
                rc = ecryptfs_encrypt_page(ecryptfs_page);
+               page_cache_release(ecryptfs_page);
                if (rc) {
                        printk(KERN_ERR "%s: Error encrypting "
                               "page; rc = [%d]\n", __FUNCTION__, rc);
-                       page_cache_release(ecryptfs_page);
                        goto out;
                }
-               page_cache_release(ecryptfs_page);
                pos += num_bytes;
        }
        if ((offset + size) > ecryptfs_file_size) {
@@ -223,7 +242,6 @@ int ecryptfs_read_lower(char *data, loff_t offset, size_t size,
                ecryptfs_inode_to_private(ecryptfs_inode);
        ssize_t octets_read;
        mm_segment_t fs_save;
-       size_t i;
        int rc = 0;
 
        mutex_lock(&inode_info->lower_file_mutex);
@@ -240,16 +258,6 @@ int ecryptfs_read_lower(char *data, loff_t offset, size_t size,
                rc = -EINVAL;
        }
        mutex_unlock(&inode_info->lower_file_mutex);
-       for (i = 0; i < size; i += PAGE_CACHE_SIZE) {
-               struct page *data_page;
-
-               data_page = virt_to_page(data + i);
-               flush_dcache_page(data_page);
-               if (rc)
-                       ClearPageUptodate(data_page);
-               else
-                       SetPageUptodate(data_page);
-       }
        return rc;
 }
 
@@ -277,10 +285,11 @@ int ecryptfs_read_lower_page_segment(struct page *page_for_ecryptfs,
        loff_t offset;
        int rc;
 
-       offset = ((page_index << PAGE_CACHE_SHIFT) + offset_in_page);
+       offset = ((((loff_t)page_index) << PAGE_CACHE_SHIFT) + offset_in_page);
        virt = kmap(page_for_ecryptfs);
        rc = ecryptfs_read_lower(virt, offset, size, ecryptfs_inode);
        kunmap(page_for_ecryptfs);
+       flush_dcache_page(page_for_ecryptfs);
        return rc;
 }
 
@@ -306,7 +315,8 @@ int ecryptfs_read(char *data, loff_t offset, size_t size,
 {
        struct page *ecryptfs_page;
        char *ecryptfs_page_virt;
-       u64 ecryptfs_file_size = i_size_read(ecryptfs_file->f_dentry->d_inode);
+       loff_t ecryptfs_file_size =
+               i_size_read(ecryptfs_file->f_dentry->d_inode);
        loff_t data_offset = 0;
        loff_t pos;
        int rc = 0;
@@ -328,8 +338,8 @@ int ecryptfs_read(char *data, loff_t offset, size_t size,
 
                if (num_bytes > total_remaining_bytes)
                        num_bytes = total_remaining_bytes;
-               ecryptfs_page = ecryptfs_get1page(ecryptfs_file,
-                                                 ecryptfs_page_idx);
+               ecryptfs_page = ecryptfs_get_locked_page(ecryptfs_file,
+                                                        ecryptfs_page_idx);
                if (IS_ERR(ecryptfs_page)) {
                        rc = PTR_ERR(ecryptfs_page);
                        printk(KERN_ERR "%s: Error getting page at "
@@ -342,6 +352,7 @@ int ecryptfs_read(char *data, loff_t offset, size_t size,
                if (rc) {
                        printk(KERN_ERR "%s: Error decrypting "
                               "page; rc = [%d]\n", __FUNCTION__, rc);
+                       ClearPageUptodate(ecryptfs_page);
                        page_cache_release(ecryptfs_page);
                        goto out;
                }
@@ -350,6 +361,9 @@ int ecryptfs_read(char *data, loff_t offset, size_t size,
                       ((char *)ecryptfs_page_virt + start_offset_in_page),
                       num_bytes);
                kunmap_atomic(ecryptfs_page_virt, KM_USER0);
+               flush_dcache_page(ecryptfs_page);
+               SetPageUptodate(ecryptfs_page);
+               unlock_page(ecryptfs_page);
                page_cache_release(ecryptfs_page);
                pos += num_bytes;
                data_offset += num_bytes;