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Diffstat (limited to 'fs/ecryptfs/mmap.c')
-rw-r--r--fs/ecryptfs/mmap.c89
1 files changed, 60 insertions, 29 deletions
diff --git a/fs/ecryptfs/mmap.c b/fs/ecryptfs/mmap.c
index 0770c4b66f5..7d5a43cb0d5 100644
--- a/fs/ecryptfs/mmap.c
+++ b/fs/ecryptfs/mmap.c
@@ -56,9 +56,6 @@ static struct page *ecryptfs_get1page(struct file *file, int index)
return read_mapping_page(mapping, index, (void *)file);
}
-static
-int write_zeros(struct file *file, pgoff_t index, int start, int num_zeros);
-
/**
* ecryptfs_fill_zeros
* @file: The ecryptfs file
@@ -101,10 +98,13 @@ int ecryptfs_fill_zeros(struct file *file, loff_t new_length)
if (old_end_page_index == new_end_page_index) {
/* Start and end are in the same page; we just need to
* set a portion of the existing page to zero's */
- rc = write_zeros(file, index, (old_end_pos_in_page + 1),
- (new_end_pos_in_page - old_end_pos_in_page));
+ rc = ecryptfs_write_zeros(file, index,
+ (old_end_pos_in_page + 1),
+ (new_end_pos_in_page
+ - old_end_pos_in_page));
if (rc)
- ecryptfs_printk(KERN_ERR, "write_zeros(file=[%p], "
+ ecryptfs_printk(KERN_ERR, "ecryptfs_write_zeros("
+ "file=[%p], "
"index=[0x%.16x], "
"old_end_pos_in_page=[d], "
"(PAGE_CACHE_SIZE - new_end_pos_in_page"
@@ -117,10 +117,10 @@ int ecryptfs_fill_zeros(struct file *file, loff_t new_length)
goto out;
}
/* Fill the remainder of the previous last page with zeros */
- rc = write_zeros(file, index, (old_end_pos_in_page + 1),
+ rc = ecryptfs_write_zeros(file, index, (old_end_pos_in_page + 1),
((PAGE_CACHE_SIZE - 1) - old_end_pos_in_page));
if (rc) {
- ecryptfs_printk(KERN_ERR, "write_zeros(file=[%p], "
+ ecryptfs_printk(KERN_ERR, "ecryptfs_write_zeros(file=[%p], "
"index=[0x%.16x], old_end_pos_in_page=[d], "
"(PAGE_CACHE_SIZE - old_end_pos_in_page)=[d]) "
"returned [%d]\n", file, index,
@@ -131,9 +131,10 @@ int ecryptfs_fill_zeros(struct file *file, loff_t new_length)
index++;
while (index < new_end_page_index) {
/* Fill all intermediate pages with zeros */
- rc = write_zeros(file, index, 0, PAGE_CACHE_SIZE);
+ rc = ecryptfs_write_zeros(file, index, 0, PAGE_CACHE_SIZE);
if (rc) {
- ecryptfs_printk(KERN_ERR, "write_zeros(file=[%p], "
+ ecryptfs_printk(KERN_ERR, "ecryptfs_write_zeros("
+ "file=[%p], "
"index=[0x%.16x], "
"old_end_pos_in_page=[d], "
"(PAGE_CACHE_SIZE - new_end_pos_in_page"
@@ -149,9 +150,9 @@ int ecryptfs_fill_zeros(struct file *file, loff_t new_length)
}
/* Fill the portion at the beginning of the last new page with
* zero's */
- rc = write_zeros(file, index, 0, (new_end_pos_in_page + 1));
+ rc = ecryptfs_write_zeros(file, index, 0, (new_end_pos_in_page + 1));
if (rc) {
- ecryptfs_printk(KERN_ERR, "write_zeros(file="
+ ecryptfs_printk(KERN_ERR, "ecryptfs_write_zeros(file="
"[%p], index=[0x%.16x], 0, "
"new_end_pos_in_page=[%d]"
"returned [%d]\n", file, index,
@@ -364,22 +365,39 @@ 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;
- char *page_virt;
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);
+ zero_user_page(page, end_byte_in_page,
+ PAGE_CACHE_SIZE - end_byte_in_page, KM_USER0);
out:
return 0;
}
+/**
+ * eCryptfs does not currently support holes. When writing after a
+ * seek past the end of the file, eCryptfs fills in 0's through to the
+ * current location. The code to fill in the 0's to all the
+ * intermediate pages calls ecryptfs_prepare_write_no_truncate().
+ */
+static int
+ecryptfs_prepare_write_no_truncate(struct file *file, struct page *page,
+ unsigned from, unsigned to)
+{
+ int rc = 0;
+
+ 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))
+ rc = ecryptfs_do_readpage(file, page, page->index);
+out:
+ return rc;
+}
+
static int ecryptfs_prepare_write(struct file *file, struct page *page,
unsigned from, unsigned to)
{
@@ -390,6 +408,23 @@ static int ecryptfs_prepare_write(struct file *file, struct page *page,
up to date. */
if (!PageUptodate(page))
rc = ecryptfs_do_readpage(file, page, page->index);
+ if (page->index != 0) {
+ loff_t end_of_prev_pg_pos =
+ (((loff_t)page->index << PAGE_CACHE_SHIFT) - 1);
+
+ if (end_of_prev_pg_pos > i_size_read(page->mapping->host)) {
+ rc = ecryptfs_truncate(file->f_path.dentry,
+ end_of_prev_pg_pos);
+ if (rc) {
+ printk(KERN_ERR "Error on attempt to "
+ "truncate to (higher) offset [%lld];"
+ " rc = [%d]\n", end_of_prev_pg_pos, 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);
+ }
out:
return rc;
}
@@ -725,7 +760,7 @@ out:
}
/**
- * write_zeros
+ * ecryptfs_write_zeros
* @file: The ecryptfs file
* @index: The index in which we are writing
* @start: The position after the last block of data
@@ -735,12 +770,11 @@ out:
*
* (start + num_zeros) must be less than or equal to PAGE_CACHE_SIZE
*/
-static
-int write_zeros(struct file *file, pgoff_t index, int start, int num_zeros)
+int
+ecryptfs_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)) {
@@ -749,18 +783,15 @@ int write_zeros(struct file *file, pgoff_t index, int start, int num_zeros)
rc = PTR_ERR(tmp_page);
goto out;
}
- rc = ecryptfs_prepare_write(file, tmp_page, start, start + num_zeros);
- if (rc) {
+ if ((rc = ecryptfs_prepare_write_no_truncate(file, tmp_page, start,
+ (start + num_zeros)))) {
ecryptfs_printk(KERN_ERR, "Error preparing to write zero's "
- "to remainder of page at index [0x%.16x]\n",
+ "to page at index [0x%.16x]\n",
index);
page_cache_release(tmp_page);
goto out;
}
- 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);
+ zero_user_page(tmp_page, start, num_zeros, KM_USER0);
rc = ecryptfs_commit_write(file, tmp_page, start, start + num_zeros);
if (rc < 0) {
ecryptfs_printk(KERN_ERR, "Error attempting to write zero's "
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-03-11 09:39:50 +0000