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Diffstat (limited to 'fs/ecryptfs/mmap.c')
-rw-r--r--fs/ecryptfs/mmap.c254
1 files changed, 143 insertions, 111 deletions
diff --git a/fs/ecryptfs/mmap.c b/fs/ecryptfs/mmap.c
index 6df1debdccc..564a1fa34b9 100644
--- a/fs/ecryptfs/mmap.c
+++ b/fs/ecryptfs/mmap.c
@@ -32,6 +32,8 @@
#include <linux/file.h>
#include <linux/crypto.h>
#include <linux/scatterlist.h>
+#include <linux/slab.h>
+#include <asm/unaligned.h>
#include "ecryptfs_kernel.h"
/**
@@ -42,17 +44,9 @@
* Returns locked and up-to-date page (if ok), with increased
* refcnt.
*/
-struct page *ecryptfs_get_locked_page(struct file *file, loff_t index)
+struct page *ecryptfs_get_locked_page(struct inode *inode, 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;
- page = read_mapping_page(mapping, index, (void *)file);
+ struct page *page = read_mapping_page(inode->i_mapping, index, NULL);
if (!IS_ERR(page))
lock_page(page);
return page;
@@ -63,6 +57,10 @@ struct page *ecryptfs_get_locked_page(struct file *file, loff_t index)
* @page: Page that is locked before this call is made
*
* Returns zero on success; non-zero otherwise
+ *
+ * This is where we encrypt the data and pass the encrypted data to
+ * the lower filesystem. In OpenPGP-compatible mode, we operate on
+ * entire underlying packets.
*/
static int ecryptfs_writepage(struct page *page, struct writeback_control *wbc)
{
@@ -71,16 +69,29 @@ static int ecryptfs_writepage(struct page *page, struct writeback_control *wbc)
rc = ecryptfs_encrypt_page(page);
if (rc) {
ecryptfs_printk(KERN_WARNING, "Error encrypting "
- "page (upper index [0x%.16x])\n", page->index);
+ "page (upper index [0x%.16lx])\n", page->index);
ClearPageUptodate(page);
goto out;
}
SetPageUptodate(page);
- unlock_page(page);
out:
+ unlock_page(page);
return rc;
}
+static void strip_xattr_flag(char *page_virt,
+ struct ecryptfs_crypt_stat *crypt_stat)
+{
+ if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) {
+ size_t written;
+
+ crypt_stat->flags &= ~ECRYPTFS_METADATA_IN_XATTR;
+ ecryptfs_write_crypt_stat_flags(page_virt, crypt_stat,
+ &written);
+ crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;
+ }
+}
+
/**
* Header Extent:
* Octets 0-7: Unencrypted file size (big-endian)
@@ -96,19 +107,6 @@ out:
* (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;
- size_t save_num_header_bytes_at_front =
- crypt_stat->num_header_bytes_at_front;
-
- crypt_stat->num_header_bytes_at_front =
- ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE;
- ecryptfs_write_header_metadata(page_virt + 20, crypt_stat, &written);
- crypt_stat->num_header_bytes_at_front =
- save_num_header_bytes_at_front;
-}
/**
* ecryptfs_copy_up_encrypted_with_header
@@ -134,33 +132,37 @@ ecryptfs_copy_up_encrypted_with_header(struct page *page,
* num_extents_per_page)
+ extent_num_in_page);
size_t num_header_extents_at_front =
- (crypt_stat->num_header_bytes_at_front
- / crypt_stat->extent_size);
+ (crypt_stat->metadata_size / crypt_stat->extent_size);
if (view_extent_num < num_header_extents_at_front) {
/* This is a header extent */
char *page_virt;
- page_virt = kmap_atomic(page, KM_USER0);
+ page_virt = kmap_atomic(page);
memset(page_virt, 0, PAGE_CACHE_SIZE);
/* TODO: Support more than one header extent */
if (view_extent_num == 0) {
+ size_t written;
+
rc = ecryptfs_read_xattr_region(
page_virt, page->mapping->host);
- set_header_info(page_virt, crypt_stat);
+ strip_xattr_flag(page_virt + 16, crypt_stat);
+ ecryptfs_write_header_metadata(page_virt + 20,
+ crypt_stat,
+ &written);
}
- kunmap_atomic(page_virt, KM_USER0);
+ kunmap_atomic(page_virt);
flush_dcache_page(page);
if (rc) {
printk(KERN_ERR "%s: Error reading xattr "
- "region; rc = [%d]\n", __FUNCTION__, rc);
+ "region; rc = [%d]\n", __func__, rc);
goto out;
}
} else {
/* This is an encrypted data extent */
loff_t lower_offset =
((view_extent_num * crypt_stat->extent_size)
- - crypt_stat->num_header_bytes_at_front);
+ - crypt_stat->metadata_size);
rc = ecryptfs_read_lower_page_segment(
page, (lower_offset >> PAGE_CACHE_SHIFT),
@@ -169,7 +171,7 @@ ecryptfs_copy_up_encrypted_with_header(struct page *page,
if (rc) {
printk(KERN_ERR "%s: Error attempting to read "
"extent at offset [%lld] in the lower "
- "file; rc = [%d]\n", __FUNCTION__,
+ "file; rc = [%d]\n", __func__,
lower_offset, rc);
goto out;
}
@@ -192,14 +194,10 @@ out:
static int ecryptfs_readpage(struct file *file, struct page *page)
{
struct ecryptfs_crypt_stat *crypt_stat =
- &ecryptfs_inode_to_private(file->f_path.dentry->d_inode)->crypt_stat;
+ &ecryptfs_inode_to_private(page->mapping->host)->crypt_stat;
int rc = 0;
- if (!crypt_stat
- || !(crypt_stat->flags & ECRYPTFS_ENCRYPTED)
- || (crypt_stat->flags & ECRYPTFS_NEW_FILE)) {
- ecryptfs_printk(KERN_DEBUG,
- "Passing through unencrypted page\n");
+ if (!crypt_stat || !(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
rc = ecryptfs_read_lower_page_segment(page, page->index, 0,
PAGE_CACHE_SIZE,
page->mapping->host);
@@ -212,7 +210,7 @@ static int ecryptfs_readpage(struct file *file, struct page *page)
"the encrypted content from the lower "
"file whilst inserting the metadata "
"from the xattr into the header; rc = "
- "[%d]\n", __FUNCTION__, rc);
+ "[%d]\n", __func__, rc);
goto out;
}
@@ -239,7 +237,7 @@ out:
ClearPageUptodate(page);
else
SetPageUptodate(page);
- ecryptfs_printk(KERN_DEBUG, "Unlocking page with index = [0x%.16x]\n",
+ ecryptfs_printk(KERN_DEBUG, "Unlocking page with index = [0x%.16lx]\n",
page->index);
unlock_page(page);
return rc;
@@ -264,36 +262,46 @@ out:
}
/**
- * ecryptfs_prepare_write
+ * ecryptfs_write_begin
* @file: The eCryptfs file
- * @page: The eCryptfs page
- * @from: The start byte from which we will write
- * @to: The end byte to which we will write
+ * @mapping: The eCryptfs object
+ * @pos: The file offset at which to start writing
+ * @len: Length of the write
+ * @flags: Various flags
+ * @pagep: Pointer to return the page
+ * @fsdata: Pointer to return fs data (unused)
*
* This function must zero any hole we create
*
* Returns zero on success; non-zero otherwise
*/
-static int ecryptfs_prepare_write(struct file *file, struct page *page,
- unsigned from, unsigned to)
+static int ecryptfs_write_begin(struct file *file,
+ struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned flags,
+ struct page **pagep, void **fsdata)
{
+ pgoff_t index = pos >> PAGE_CACHE_SHIFT;
+ struct page *page;
loff_t prev_page_end_size;
int rc = 0;
+ page = grab_cache_page_write_begin(mapping, index, flags);
+ if (!page)
+ return -ENOMEM;
+ *pagep = page;
+
+ prev_page_end_size = ((loff_t)index << PAGE_CACHE_SHIFT);
if (!PageUptodate(page)) {
struct ecryptfs_crypt_stat *crypt_stat =
- &ecryptfs_inode_to_private(
- file->f_path.dentry->d_inode)->crypt_stat;
+ &ecryptfs_inode_to_private(mapping->host)->crypt_stat;
- if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)
- || (crypt_stat->flags & ECRYPTFS_NEW_FILE)) {
+ if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
rc = ecryptfs_read_lower_page_segment(
- page, page->index, 0, PAGE_CACHE_SIZE,
- page->mapping->host);
+ page, index, 0, PAGE_CACHE_SIZE, mapping->host);
if (rc) {
printk(KERN_ERR "%s: Error attemping to read "
"lower page segment; rc = [%d]\n",
- __FUNCTION__, rc);
+ __func__, rc);
ClearPageUptodate(page);
goto out;
} else
@@ -308,47 +316,53 @@ static int ecryptfs_prepare_write(struct file *file, struct page *page,
"from the lower file whilst "
"inserting the metadata from "
"the xattr into the header; rc "
- "= [%d]\n", __FUNCTION__, rc);
+ "= [%d]\n", __func__, rc);
ClearPageUptodate(page);
goto out;
}
SetPageUptodate(page);
} else {
rc = ecryptfs_read_lower_page_segment(
- page, page->index, 0, PAGE_CACHE_SIZE,
- page->mapping->host);
+ page, index, 0, PAGE_CACHE_SIZE,
+ mapping->host);
if (rc) {
printk(KERN_ERR "%s: Error reading "
"page; rc = [%d]\n",
- __FUNCTION__, rc);
+ __func__, rc);
ClearPageUptodate(page);
goto out;
}
SetPageUptodate(page);
}
} else {
- rc = ecryptfs_decrypt_page(page);
- if (rc) {
- printk(KERN_ERR "%s: Error decrypting page "
- "at index [%ld]; rc = [%d]\n",
- __FUNCTION__, page->index, rc);
- ClearPageUptodate(page);
- goto out;
+ if (prev_page_end_size
+ >= i_size_read(page->mapping->host)) {
+ zero_user(page, 0, PAGE_CACHE_SIZE);
+ SetPageUptodate(page);
+ } else if (len < PAGE_CACHE_SIZE) {
+ rc = ecryptfs_decrypt_page(page);
+ if (rc) {
+ printk(KERN_ERR "%s: Error decrypting "
+ "page at index [%ld]; "
+ "rc = [%d]\n",
+ __func__, page->index, rc);
+ ClearPageUptodate(page);
+ goto out;
+ }
+ SetPageUptodate(page);
}
- SetPageUptodate(page);
}
}
- 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 (index != 0) {
if (prev_page_end_size > i_size_read(page->mapping->host)) {
rc = ecryptfs_truncate(file->f_path.dentry,
prev_page_end_size);
if (rc) {
printk(KERN_ERR "%s: Error on attempt to "
"truncate to (higher) offset [%lld];"
- " rc = [%d]\n", __FUNCTION__,
+ " rc = [%d]\n", __func__,
prev_page_end_size, rc);
goto out;
}
@@ -356,10 +370,15 @@ static int ecryptfs_prepare_write(struct file *file, struct page *page,
}
/* 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))
+ if ((i_size_read(mapping->host) == prev_page_end_size)
+ && (pos != 0))
zero_user(page, 0, PAGE_CACHE_SIZE);
out:
+ if (unlikely(rc)) {
+ unlock_page(page);
+ page_cache_release(page);
+ *pagep = NULL;
+ }
return rc;
}
@@ -372,7 +391,6 @@ out:
*/
static int ecryptfs_write_inode_size_to_header(struct inode *ecryptfs_inode)
{
- u64 file_size;
char *file_size_virt;
int rc;
@@ -381,15 +399,15 @@ static int ecryptfs_write_inode_size_to_header(struct inode *ecryptfs_inode)
rc = -ENOMEM;
goto out;
}
- file_size = (u64)i_size_read(ecryptfs_inode);
- file_size = cpu_to_be64(file_size);
- memcpy(file_size_virt, &file_size, sizeof(u64));
+ put_unaligned_be64(i_size_read(ecryptfs_inode), file_size_virt);
rc = ecryptfs_write_lower(ecryptfs_inode, file_size_virt, 0,
sizeof(u64));
kfree(file_size_virt);
- if (rc)
+ if (rc < 0)
printk(KERN_ERR "%s: Error writing file size to header; "
- "rc = [%d]\n", __FUNCTION__, rc);
+ "rc = [%d]\n", __func__, rc);
+ else
+ rc = 0;
out:
return rc;
}
@@ -403,7 +421,6 @@ static int ecryptfs_write_inode_size_to_xattr(struct inode *ecryptfs_inode)
struct dentry *lower_dentry =
ecryptfs_inode_to_private(ecryptfs_inode)->lower_file->f_dentry;
struct inode *lower_inode = lower_dentry->d_inode;
- u64 file_size;
int rc;
if (!lower_inode->i_op->getxattr || !lower_inode->i_op->setxattr) {
@@ -424,9 +441,7 @@ static int ecryptfs_write_inode_size_to_xattr(struct inode *ecryptfs_inode)
xattr_virt, PAGE_CACHE_SIZE);
if (size < 0)
size = 8;
- file_size = (u64)i_size_read(ecryptfs_inode);
- file_size = cpu_to_be64(file_size);
- memcpy(xattr_virt, &file_size, sizeof(u64));
+ put_unaligned_be64(i_size_read(ecryptfs_inode), xattr_virt);
rc = lower_inode->i_op->setxattr(lower_dentry, ECRYPTFS_XATTR_NAME,
xattr_virt, size, 0);
mutex_unlock(&lower_inode->i_mutex);
@@ -443,6 +458,7 @@ int ecryptfs_write_inode_size_to_metadata(struct inode *ecryptfs_inode)
struct ecryptfs_crypt_stat *crypt_stat;
crypt_stat = &ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat;
+ BUG_ON(!(crypt_stat->flags & ECRYPTFS_ENCRYPTED));
if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR)
return ecryptfs_write_inode_size_to_xattr(ecryptfs_inode);
else
@@ -450,59 +466,75 @@ int ecryptfs_write_inode_size_to_metadata(struct inode *ecryptfs_inode)
}
/**
- * ecryptfs_commit_write
+ * ecryptfs_write_end
* @file: The eCryptfs file object
+ * @mapping: The eCryptfs object
+ * @pos: The file position
+ * @len: The length of the data (unused)
+ * @copied: The amount of data copied
* @page: The eCryptfs page
- * @from: Ignored (we rotate the page IV on each write)
- * @to: Ignored
- *
- * This is where we encrypt the data and pass the encrypted data to
- * the lower filesystem. In OpenPGP-compatible mode, we operate on
- * entire underlying packets.
+ * @fsdata: The fsdata (unused)
*/
-static int ecryptfs_commit_write(struct file *file, struct page *page,
- unsigned from, unsigned to)
+static int ecryptfs_write_end(struct file *file,
+ struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned copied,
+ struct page *page, void *fsdata)
{
- loff_t pos;
- struct inode *ecryptfs_inode = page->mapping->host;
+ pgoff_t index = pos >> PAGE_CACHE_SHIFT;
+ unsigned from = pos & (PAGE_CACHE_SIZE - 1);
+ unsigned to = from + copied;
+ struct inode *ecryptfs_inode = mapping->host;
struct ecryptfs_crypt_stat *crypt_stat =
- &ecryptfs_inode_to_private(file->f_path.dentry->d_inode)->crypt_stat;
+ &ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat;
int rc;
- 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);
- 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"
- "(page w/ index = [0x%.16x], to = [%d])\n", page->index,
- to);
+ "(page w/ index = [0x%.16lx], to = [%d])\n", index, to);
+ if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
+ rc = ecryptfs_write_lower_page_segment(ecryptfs_inode, page, 0,
+ to);
+ if (!rc) {
+ rc = copied;
+ fsstack_copy_inode_size(ecryptfs_inode,
+ ecryptfs_inode_to_lower(ecryptfs_inode));
+ }
+ goto out;
+ }
+ if (!PageUptodate(page)) {
+ if (copied < PAGE_CACHE_SIZE) {
+ rc = 0;
+ goto out;
+ }
+ SetPageUptodate(page);
+ }
/* Fills in zeros if 'to' goes beyond inode size */
rc = fill_zeros_to_end_of_page(page, to);
if (rc) {
ecryptfs_printk(KERN_WARNING, "Error attempting to fill "
- "zeros in page with index = [0x%.16x]\n",
- page->index);
+ "zeros in page with index = [0x%.16lx]\n", index);
goto out;
}
rc = ecryptfs_encrypt_page(page);
if (rc) {
ecryptfs_printk(KERN_WARNING, "Error encrypting page (upper "
- "index [0x%.16x])\n", page->index);
+ "index [0x%.16lx])\n", index);
goto out;
}
- pos = (((loff_t)page->index) << PAGE_CACHE_SHIFT) + to;
- if (pos > i_size_read(ecryptfs_inode)) {
- i_size_write(ecryptfs_inode, pos);
+ if (pos + copied > i_size_read(ecryptfs_inode)) {
+ i_size_write(ecryptfs_inode, pos + copied);
ecryptfs_printk(KERN_DEBUG, "Expanded file size to "
- "[0x%.16x]\n", i_size_read(ecryptfs_inode));
+ "[0x%.16llx]\n",
+ (unsigned long long)i_size_read(ecryptfs_inode));
}
rc = ecryptfs_write_inode_size_to_metadata(ecryptfs_inode);
if (rc)
printk(KERN_ERR "Error writing inode size to metadata; "
"rc = [%d]\n", rc);
+ else
+ rc = copied;
out:
+ unlock_page(page);
+ page_cache_release(page);
return rc;
}
@@ -520,10 +552,10 @@ static sector_t ecryptfs_bmap(struct address_space *mapping, sector_t block)
return rc;
}
-struct address_space_operations ecryptfs_aops = {
+const struct address_space_operations ecryptfs_aops = {
.writepage = ecryptfs_writepage,
.readpage = ecryptfs_readpage,
- .prepare_write = ecryptfs_prepare_write,
- .commit_write = ecryptfs_commit_write,
+ .write_begin = ecryptfs_write_begin,
+ .write_end = ecryptfs_write_end,
.bmap = ecryptfs_bmap,
};
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-10 01:59:49 +0000