struct kmem_cache *ecryptfs_lower_page_cache;
/**
- * ecryptfs_get1page
+ * ecryptfs_get_locked_page
*
* Get one page from cache or lower f/s, return error otherwise.
*
- * Returns unlocked and up-to-date page (if ok), with increased
+ * Returns locked and up-to-date page (if ok), with increased
* refcnt.
*/
-struct page *ecryptfs_get1page(struct file *file, loff_t index)
+struct page *ecryptfs_get_locked_page(struct file *file, loff_t index)
{
struct dentry *dentry;
struct inode *inode;
struct address_space *mapping;
+ struct page *page;
dentry = file->f_path.dentry;
inode = dentry->d_inode;
mapping = inode->i_mapping;
- return read_mapping_page(mapping, index, (void *)file);
+ page = read_mapping_page(mapping, index, (void *)file);
+ if (!IS_ERR(page))
+ lock_page(page);
+ return page;
}
/**
kunmap_atomic(page_virt, KM_USER0);
flush_dcache_page(page);
if (rc) {
- ClearPageUptodate(page);
printk(KERN_ERR "%s: Error reading xattr "
"region; rc = [%d]\n", __FUNCTION__, rc);
goto out;
}
- SetPageUptodate(page);
} else {
/* This is an encrypted data extent */
loff_t lower_offset =
}
}
out:
+ if (rc)
+ ClearPageUptodate(page);
+ else
+ SetPageUptodate(page);
ecryptfs_printk(KERN_DEBUG, "Unlocking page with index = [0x%.16x]\n",
page->index);
unlock_page(page);
end_byte_in_page = i_size_read(inode) % PAGE_CACHE_SIZE;
if (to > end_byte_in_page)
end_byte_in_page = to;
- zero_user_page(page, end_byte_in_page,
- PAGE_CACHE_SIZE - end_byte_in_page, KM_USER0);
+ zero_user_segment(page, end_byte_in_page, PAGE_CACHE_SIZE);
out:
return 0;
}
+/* This function must zero any hole we create */
static int ecryptfs_prepare_write(struct file *file, struct page *page,
unsigned from, unsigned to)
{
int rc = 0;
+ loff_t prev_page_end_size;
- if (from == 0 && to == PAGE_CACHE_SIZE)
- goto out; /* If we are writing a full page, it will be
- up to date. */
- if (!PageUptodate(page))
+ if (!PageUptodate(page)) {
rc = ecryptfs_read_lower_page_segment(page, page->index, 0,
PAGE_CACHE_SIZE,
page->mapping->host);
- if (page->index != 0) {
- loff_t end_of_prev_pg_pos =
- (((loff_t)page->index << PAGE_CACHE_SHIFT) - 1);
+ if (rc) {
+ printk(KERN_ERR "%s: Error attemping to read lower "
+ "page segment; rc = [%d]\n", __FUNCTION__, rc);
+ ClearPageUptodate(page);
+ goto out;
+ } else
+ SetPageUptodate(page);
+ }
- if (end_of_prev_pg_pos > i_size_read(page->mapping->host)) {
+ prev_page_end_size = ((loff_t)page->index << PAGE_CACHE_SHIFT);
+
+ /*
+ * If creating a page or more of holes, zero them out via truncate.
+ * Note, this will increase i_size.
+ */
+ if (page->index != 0) {
+ if (prev_page_end_size > i_size_read(page->mapping->host)) {
rc = ecryptfs_truncate(file->f_path.dentry,
- end_of_prev_pg_pos);
+ prev_page_end_size);
if (rc) {
printk(KERN_ERR "Error on attempt to "
"truncate to (higher) offset [%lld];"
- " rc = [%d]\n", end_of_prev_pg_pos, rc);
+ " rc = [%d]\n", prev_page_end_size, rc);
goto out;
}
}
- if (end_of_prev_pg_pos + 1 > i_size_read(page->mapping->host))
- zero_user_page(page, 0, PAGE_CACHE_SIZE, KM_USER0);
+ }
+ /*
+ * Writing to a new page, and creating a small hole from start of page?
+ * Zero it out.
+ */
+ if ((i_size_read(page->mapping->host) == prev_page_end_size) &&
+ (from != 0)) {
+ zero_user(page, 0, PAGE_CACHE_SIZE);
}
out:
return rc;