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eCryptfs: update metadata read/write functions

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Update the metadata read/write functions and grow_file() to use the
read_write.c routines.  Do not open another lower file; use the persistent
lower file instead.  Provide a separate function for
crypto.c::ecryptfs_read_xattr_region() to get to the lower xattr without
having to go through the eCryptfs getxattr.

Signed-off-by: Michael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Michael Halcrow
2007-10-16 01:28:10 -07:00
committed by Linus Torvalds
parent 4981e081cf
commit d7cdc5febf
5 changed files with 114 additions and 133 deletions
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127
fs/ecryptfs/crypto.c
View File

@@ -1342,21 +1342,28 @@ out:
return rc;
}
int ecryptfs_read_and_validate_header_region(char *data, struct dentry *dentry,
struct vfsmount *mnt)
int ecryptfs_read_and_validate_header_region(char *data,
struct inode *ecryptfs_inode)
{
struct ecryptfs_crypt_stat *crypt_stat =
&(ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat);
int rc;
rc = ecryptfs_read_header_region(data, dentry, mnt);
if (rc)
rc = ecryptfs_read_lower(data, 0, crypt_stat->extent_size,
ecryptfs_inode);
if (rc) {
printk(KERN_ERR "%s: Error reading header region; rc = [%d]\n",
__FUNCTION__, rc);
goto out;
if (!contains_ecryptfs_marker(data + ECRYPTFS_FILE_SIZE_BYTES))
}
if (!contains_ecryptfs_marker(data + ECRYPTFS_FILE_SIZE_BYTES)) {
rc = -EINVAL;
ecryptfs_printk(KERN_DEBUG, "Valid marker not found\n");
}
out:
return rc;
}
void
ecryptfs_write_header_metadata(char *virt,
struct ecryptfs_crypt_stat *crypt_stat,
@@ -1441,24 +1448,19 @@ static int ecryptfs_write_headers_virt(char *page_virt, size_t *size,
static int
ecryptfs_write_metadata_to_contents(struct ecryptfs_crypt_stat *crypt_stat,
struct file *lower_file, char *page_virt)
struct dentry *ecryptfs_dentry,
char *page_virt)
{
mm_segment_t oldfs;
int current_header_page;
int header_pages;
ssize_t size;
int rc = 0;
int rc;
lower_file->f_pos = 0;
oldfs = get_fs();
set_fs(get_ds());
size = vfs_write(lower_file, (char __user *)page_virt, PAGE_CACHE_SIZE,
&lower_file->f_pos);
if (size < 0) {
rc = (int)size;
printk(KERN_ERR "Error attempting to write lower page; "
"rc = [%d]\n", rc);
set_fs(oldfs);
rc = ecryptfs_write_lower(ecryptfs_dentry->d_inode, page_virt,
0, PAGE_CACHE_SIZE);
if (rc) {
printk(KERN_ERR "%s: Error attempting to write header "
"information to lower file; rc = [%d]\n", __FUNCTION__,
rc);
goto out;
}
header_pages = ((crypt_stat->extent_size
@@ -1467,18 +1469,19 @@ ecryptfs_write_metadata_to_contents(struct ecryptfs_crypt_stat *crypt_stat,
memset(page_virt, 0, PAGE_CACHE_SIZE);
current_header_page = 1;
while (current_header_page < header_pages) {
size = vfs_write(lower_file, (char __user *)page_virt,
PAGE_CACHE_SIZE, &lower_file->f_pos);
if (size < 0) {
rc = (int)size;
printk(KERN_ERR "Error attempting to write lower page; "
"rc = [%d]\n", rc);
set_fs(oldfs);
loff_t offset;
offset = (current_header_page << PAGE_CACHE_SHIFT);
if ((rc = ecryptfs_write_lower(ecryptfs_dentry->d_inode,
page_virt, offset,
PAGE_CACHE_SIZE))) {
printk(KERN_ERR "%s: Error attempting to write header "
"information to lower file; rc = [%d]\n",
__FUNCTION__, rc);
goto out;
}
current_header_page++;
}
set_fs(oldfs);
out:
return rc;
}
@@ -1498,7 +1501,6 @@ ecryptfs_write_metadata_to_xattr(struct dentry *ecryptfs_dentry,
/**
* ecryptfs_write_metadata
* @ecryptfs_dentry: The eCryptfs dentry
* @lower_file: The lower file struct, which was returned from dentry_open
*
* Write the file headers out. This will likely involve a userspace
* callout, in which the session key is encrypted with one or more
@@ -1506,22 +1508,21 @@ ecryptfs_write_metadata_to_xattr(struct dentry *ecryptfs_dentry,
* retrieved via a prompt. Exactly what happens at this point should
* be policy-dependent.
*
* TODO: Support header information spanning multiple pages
*
* Returns zero on success; non-zero on error
*/
int ecryptfs_write_metadata(struct dentry *ecryptfs_dentry,
struct file *lower_file)
int ecryptfs_write_metadata(struct dentry *ecryptfs_dentry)
{
struct ecryptfs_crypt_stat *crypt_stat;
struct ecryptfs_crypt_stat *crypt_stat =
&ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->crypt_stat;
char *page_virt;
size_t size;
size_t size = 0;
int rc = 0;
crypt_stat = &ecryptfs_inode_to_private(
ecryptfs_dentry->d_inode)->crypt_stat;
if (likely(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
if (!(crypt_stat->flags & ECRYPTFS_KEY_VALID)) {
ecryptfs_printk(KERN_DEBUG, "Key is "
"invalid; bailing out\n");
printk(KERN_ERR "Key is invalid; bailing out\n");
rc = -EINVAL;
goto out;
}
@@ -1550,7 +1551,8 @@ int ecryptfs_write_metadata(struct dentry *ecryptfs_dentry,
crypt_stat, page_virt,
size);
else
rc = ecryptfs_write_metadata_to_contents(crypt_stat, lower_file,
rc = ecryptfs_write_metadata_to_contents(crypt_stat,
ecryptfs_dentry,
page_virt);
if (rc) {
printk(KERN_ERR "Error writing metadata out to lower file; "
@@ -1678,15 +1680,17 @@ out:
*
* Returns zero on success; non-zero on error
*/
int ecryptfs_read_xattr_region(char *page_virt, struct dentry *ecryptfs_dentry)
int ecryptfs_read_xattr_region(char *page_virt, struct inode *ecryptfs_inode)
{
struct dentry *lower_dentry =
ecryptfs_inode_to_private(ecryptfs_inode)->lower_file->f_dentry;
ssize_t size;
int rc = 0;
size = ecryptfs_getxattr(ecryptfs_dentry, ECRYPTFS_XATTR_NAME,
page_virt, ECRYPTFS_DEFAULT_EXTENT_SIZE);
size = ecryptfs_getxattr_lower(lower_dentry, ECRYPTFS_XATTR_NAME,
page_virt, ECRYPTFS_DEFAULT_EXTENT_SIZE);
if (size < 0) {
printk(KERN_DEBUG "Error attempting to read the [%s] "
printk(KERN_ERR "Error attempting to read the [%s] "
"xattr from the lower file; return value = [%zd]\n",
ECRYPTFS_XATTR_NAME, size);
rc = -EINVAL;
@@ -1701,7 +1705,7 @@ int ecryptfs_read_and_validate_xattr_region(char *page_virt,
{
int rc;
rc = ecryptfs_read_xattr_region(page_virt, ecryptfs_dentry);
rc = ecryptfs_read_xattr_region(page_virt, ecryptfs_dentry->d_inode);
if (rc)
goto out;
if (!contains_ecryptfs_marker(page_virt + ECRYPTFS_FILE_SIZE_BYTES)) {
@@ -1715,8 +1719,6 @@ out:
/**
* ecryptfs_read_metadata
* @ecryptfs_dentry: The eCryptfs dentry
* @lower_file: The lower file from which to read the metadata
*
* Common entry point for reading file metadata. From here, we could
* retrieve the header information from the header region of the file,
@@ -1727,15 +1729,13 @@ out:
*
* Returns zero if valid headers found and parsed; non-zero otherwise
*/
int ecryptfs_read_metadata(struct dentry *ecryptfs_dentry,
struct file *lower_file)
int ecryptfs_read_metadata(struct dentry *ecryptfs_dentry)
{
int rc = 0;
char *page_virt = NULL;
mm_segment_t oldfs;
ssize_t bytes_read;
struct inode *ecryptfs_inode = ecryptfs_dentry->d_inode;
struct ecryptfs_crypt_stat *crypt_stat =
&ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->crypt_stat;
&ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat;
struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
&ecryptfs_superblock_to_private(
ecryptfs_dentry->d_sb)->mount_crypt_stat;
@@ -1746,27 +1746,18 @@ int ecryptfs_read_metadata(struct dentry *ecryptfs_dentry,
page_virt = kmem_cache_alloc(ecryptfs_header_cache_1, GFP_USER);
if (!page_virt) {
rc = -ENOMEM;
ecryptfs_printk(KERN_ERR, "Unable to allocate page_virt\n");
printk(KERN_ERR "%s: Unable to allocate page_virt\n",
__FUNCTION__);
goto out;
}
lower_file->f_pos = 0;
oldfs = get_fs();
set_fs(get_ds());
bytes_read = lower_file->f_op->read(lower_file,
(char __user *)page_virt,
ECRYPTFS_DEFAULT_EXTENT_SIZE,
&lower_file->f_pos);
set_fs(oldfs);
if (bytes_read != ECRYPTFS_DEFAULT_EXTENT_SIZE) {
rc = -EINVAL;
goto out;
}
rc = ecryptfs_read_headers_virt(page_virt, crypt_stat,
ecryptfs_dentry,
ECRYPTFS_VALIDATE_HEADER_SIZE);
rc = ecryptfs_read_lower(page_virt, 0, crypt_stat->extent_size,
ecryptfs_inode);
if (!rc)
rc = ecryptfs_read_headers_virt(page_virt, crypt_stat,
ecryptfs_dentry,
ECRYPTFS_VALIDATE_HEADER_SIZE);
if (rc) {
rc = ecryptfs_read_xattr_region(page_virt,
ecryptfs_dentry);
rc = ecryptfs_read_xattr_region(page_virt, ecryptfs_inode);
if (rc) {
printk(KERN_DEBUG "Valid eCryptfs headers not found in "
"file header region or xattr region\n");