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eCryptfs: replace encrypt, decrypt, and inode size write

Browse source 
Replace page encryption and decryption routines and inode size write routine
with versions that utilize the read_write.c functions.

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 01:28:08 -07:00 committed by Linus Torvalds
parent da0102a10a
commit 0216f7f792
5 changed files with 288 additions and 304 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

421
fs/ecryptfs/crypto.c
View file

@ -467,102 +467,49 @@ static int ecryptfs_read_in_page(struct ecryptfs_page_crypt_context *ctx,
}
/**
* ecryptfs_encrypt_page
* @ctx: The context of the page
* ecryptfs_lower_offset_for_extent
*
* Encrypt an eCryptfs page. This is done on a per-extent basis. Note
* that eCryptfs pages may straddle the lower pages -- for instance,
* if the file was created on a machine with an 8K page size
* (resulting in an 8K header), and then the file is copied onto a
* host with a 32K page size, then when reading page 0 of the eCryptfs
* file, 24K of page 0 of the lower file will be read and decrypted,
* and then 8K of page 1 of the lower file will be read and decrypted.
*
* The actual operations performed on each page depends on the
* contents of the ecryptfs_page_crypt_context struct.
*
* Returns zero on success; negative on error
* Convert an eCryptfs page index into a lower byte offset
*/
int ecryptfs_encrypt_page(struct ecryptfs_page_crypt_context *ctx)
void ecryptfs_lower_offset_for_extent(loff_t *offset, loff_t extent_num,
struct ecryptfs_crypt_stat *crypt_stat)
{
char extent_iv[ECRYPTFS_MAX_IV_BYTES];
unsigned long base_extent;
unsigned long extent_offset = 0;
unsigned long lower_page_idx = 0;
unsigned long prior_lower_page_idx = 0;
struct page *lower_page;
struct inode *lower_inode;
struct ecryptfs_inode_info *inode_info;
struct ecryptfs_crypt_stat *crypt_stat;
int rc = 0;
int lower_byte_offset = 0;
int orig_byte_offset = 0;
int num_extents_per_page;
#define ECRYPTFS_PAGE_STATE_UNREAD 0
#define ECRYPTFS_PAGE_STATE_READ 1
#define ECRYPTFS_PAGE_STATE_MODIFIED 2
#define ECRYPTFS_PAGE_STATE_WRITTEN 3
int page_state;
(*offset) = ((crypt_stat->extent_size
* crypt_stat->num_header_extents_at_front)
+ (crypt_stat->extent_size * extent_num));
}
lower_inode = ecryptfs_inode_to_lower(ctx->page->mapping->host);
inode_info = ecryptfs_inode_to_private(ctx->page->mapping->host);
crypt_stat = &inode_info->crypt_stat;
if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
rc = ecryptfs_copy_page_to_lower(ctx->page, lower_inode,
ctx->param.lower_file);
if (rc)
ecryptfs_printk(KERN_ERR, "Error attempting to copy "
"page at index [0x%.16x]\n",
ctx->page->index);
goto out;
}
num_extents_per_page = PAGE_CACHE_SIZE / crypt_stat->extent_size;
base_extent = (ctx->page->index * num_extents_per_page);
page_state = ECRYPTFS_PAGE_STATE_UNREAD;
while (extent_offset < num_extents_per_page) {
ecryptfs_extent_to_lwr_pg_idx_and_offset(
&lower_page_idx, &lower_byte_offset, crypt_stat,
(base_extent + extent_offset));
if (prior_lower_page_idx != lower_page_idx
&& page_state == ECRYPTFS_PAGE_STATE_MODIFIED) {
rc = ecryptfs_write_out_page(ctx, lower_page,
lower_inode,
orig_byte_offset,
(PAGE_CACHE_SIZE
- orig_byte_offset));
if (rc) {
ecryptfs_printk(KERN_ERR, "Error attempting "
"to write out page; rc = [%d]"
"\n", rc);
goto out;
}
page_state = ECRYPTFS_PAGE_STATE_WRITTEN;
}
if (page_state == ECRYPTFS_PAGE_STATE_UNREAD
|| page_state == ECRYPTFS_PAGE_STATE_WRITTEN) {
rc = ecryptfs_read_in_page(ctx, &lower_page,
lower_inode, lower_page_idx,
lower_byte_offset);
if (rc) {
ecryptfs_printk(KERN_ERR, "Error attempting "
"to read in lower page with "
"index [0x%.16x]; rc = [%d]\n",
lower_page_idx, rc);
goto out;
}
orig_byte_offset = lower_byte_offset;
prior_lower_page_idx = lower_page_idx;
page_state = ECRYPTFS_PAGE_STATE_READ;
}
BUG_ON(!(page_state == ECRYPTFS_PAGE_STATE_MODIFIED
|| page_state == ECRYPTFS_PAGE_STATE_READ));
/**
* ecryptfs_encrypt_extent
* @enc_extent_page: Allocated page into which to encrypt the data in
* @page
* @crypt_stat: crypt_stat containing cryptographic context for the
* encryption operation
* @page: Page containing plaintext data extent to encrypt
* @extent_offset: Page extent offset for use in generating IV
*
* Encrypts one extent of data.
*
* Return zero on success; non-zero otherwise
*/
static int ecryptfs_encrypt_extent(struct page *enc_extent_page,
struct ecryptfs_crypt_stat *crypt_stat,
struct page *page,
unsigned long extent_offset)
{
unsigned long extent_base;
char extent_iv[ECRYPTFS_MAX_IV_BYTES];
int rc;
extent_base = (page->index
* (PAGE_CACHE_SIZE / crypt_stat->extent_size));
rc = ecryptfs_derive_iv(extent_iv, crypt_stat,
(base_extent + extent_offset));
(extent_base + extent_offset));
if (rc) {
ecryptfs_printk(KERN_ERR, "Error attempting to "
"derive IV for extent [0x%.16x]; "
"rc = [%d]\n",
(base_extent + extent_offset), rc);
"rc = [%d]\n", (extent_base + extent_offset),
rc);
goto out;
}
if (unlikely(ecryptfs_verbosity > 0)) {
@ -572,43 +519,173 @@ int ecryptfs_encrypt_page(struct ecryptfs_page_crypt_context *ctx)
ecryptfs_printk(KERN_DEBUG, "First 8 bytes before "
"encryption:\n");
ecryptfs_dump_hex((char *)
(page_address(ctx->page)
+ (extent_offset
* crypt_stat->extent_size)), 8);
(page_address(page)
+ (extent_offset * crypt_stat->extent_size)),
8);
}
rc = ecryptfs_encrypt_page_offset(
crypt_stat, lower_page, lower_byte_offset, ctx->page,
(extent_offset * crypt_stat->extent_size),
rc = ecryptfs_encrypt_page_offset(crypt_stat, enc_extent_page, 0,
page, (extent_offset
* crypt_stat->extent_size),
crypt_stat->extent_size, extent_iv);
ecryptfs_printk(KERN_DEBUG, "Encrypt extent [0x%.16x]; "
"rc = [%d]\n",
(base_extent + extent_offset), rc);
if (rc < 0) {
printk(KERN_ERR "%s: Error attempting to encrypt page with "
"page->index = [%ld], extent_offset = [%ld]; "
"rc = [%d]\n", __FUNCTION__, page->index, extent_offset,
rc);
goto out;
}
rc = 0;
if (unlikely(ecryptfs_verbosity > 0)) {
ecryptfs_printk(KERN_DEBUG, "Encrypt extent [0x%.16x]; "
"rc = [%d]\n", (extent_base + extent_offset),
rc);
ecryptfs_printk(KERN_DEBUG, "First 8 bytes after "
"encryption:\n");
ecryptfs_dump_hex((char *)(page_address(lower_page)
+ lower_byte_offset), 8);
ecryptfs_dump_hex((char *)(page_address(enc_extent_page)), 8);
}
out:
return rc;
}
/**
* ecryptfs_encrypt_page
* @page: Page mapped from the eCryptfs inode for the file; contains
* decrypted content that needs to be encrypted (to a temporary
* page; not in place) and written out to the lower file
*
* Encrypt an eCryptfs page. This is done on a per-extent basis. Note
* that eCryptfs pages may straddle the lower pages -- for instance,
* if the file was created on a machine with an 8K page size
* (resulting in an 8K header), and then the file is copied onto a
* host with a 32K page size, then when reading page 0 of the eCryptfs
* file, 24K of page 0 of the lower file will be read and decrypted,
* and then 8K of page 1 of the lower file will be read and decrypted.
*
* Returns zero on success; negative on error
*/
int ecryptfs_encrypt_page(struct page *page)
{
struct inode *ecryptfs_inode;
struct ecryptfs_crypt_stat *crypt_stat;
char *enc_extent_virt = NULL;
struct page *enc_extent_page;
loff_t extent_offset;
int rc = 0;
ecryptfs_inode = page->mapping->host;
crypt_stat =
&(ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat);
if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
rc = ecryptfs_write_lower_page_segment(ecryptfs_inode, page,
0, PAGE_CACHE_SIZE);
if (rc)
printk(KERN_ERR "%s: Error attempting to copy "
"page at index [%ld]\n", __FUNCTION__,
page->index);
goto out;
}
enc_extent_virt = kmalloc(PAGE_CACHE_SIZE, GFP_USER);
if (!enc_extent_virt) {
rc = -ENOMEM;
ecryptfs_printk(KERN_ERR, "Error allocating memory for "
"encrypted extent\n");
goto out;
}
enc_extent_page = virt_to_page(enc_extent_virt);
for (extent_offset = 0;
extent_offset < (PAGE_CACHE_SIZE / crypt_stat->extent_size);
extent_offset++) {
loff_t offset;
rc = ecryptfs_encrypt_extent(enc_extent_page, crypt_stat, page,
extent_offset);
if (rc) {
printk(KERN_ERR "%s: Error encrypting extent; "
"rc = [%d]\n", __FUNCTION__, rc);
goto out;
}
ecryptfs_lower_offset_for_extent(
&offset, ((page->index * (PAGE_CACHE_SIZE
/ crypt_stat->extent_size))
+ extent_offset), crypt_stat);
rc = ecryptfs_write_lower(ecryptfs_inode, enc_extent_virt,
offset, crypt_stat->extent_size);
if (rc) {
ecryptfs_printk(KERN_ERR, "Error attempting "
"to write lower page; rc = [%d]"
"\n", rc);
goto out;
}
page_state = ECRYPTFS_PAGE_STATE_MODIFIED;
extent_offset++;
}
BUG_ON(orig_byte_offset != 0);
rc = ecryptfs_write_out_page(ctx, lower_page, lower_inode, 0,
(lower_byte_offset
+ crypt_stat->extent_size));
out:
kfree(enc_extent_virt);
return rc;
}
static int ecryptfs_decrypt_extent(struct page *page,
struct ecryptfs_crypt_stat *crypt_stat,
struct page *enc_extent_page,
unsigned long extent_offset)
{
unsigned long extent_base;
char extent_iv[ECRYPTFS_MAX_IV_BYTES];
int rc;
extent_base = (page->index
* (PAGE_CACHE_SIZE / crypt_stat->extent_size));
rc = ecryptfs_derive_iv(extent_iv, crypt_stat,
(extent_base + extent_offset));
if (rc) {
ecryptfs_printk(KERN_ERR, "Error attempting to write out "
"page; rc = [%d]\n", rc);
ecryptfs_printk(KERN_ERR, "Error attempting to "
"derive IV for extent [0x%.16x]; "
"rc = [%d]\n", (extent_base + extent_offset),
rc);
goto out;
}
if (unlikely(ecryptfs_verbosity > 0)) {
ecryptfs_printk(KERN_DEBUG, "Decrypting extent "
"with iv:\n");
ecryptfs_dump_hex(extent_iv, crypt_stat->iv_bytes);
ecryptfs_printk(KERN_DEBUG, "First 8 bytes before "
"decryption:\n");
ecryptfs_dump_hex((char *)
(page_address(enc_extent_page)
+ (extent_offset * crypt_stat->extent_size)),
8);
}
rc = ecryptfs_decrypt_page_offset(crypt_stat, page,
(extent_offset
* crypt_stat->extent_size),
enc_extent_page, 0,
crypt_stat->extent_size, extent_iv);
if (rc < 0) {
printk(KERN_ERR "%s: Error attempting to decrypt to page with "
"page->index = [%ld], extent_offset = [%ld]; "
"rc = [%d]\n", __FUNCTION__, page->index, extent_offset,
rc);
goto out;
}
rc = 0;
if (unlikely(ecryptfs_verbosity > 0)) {
ecryptfs_printk(KERN_DEBUG, "Decrypt extent [0x%.16x]; "
"rc = [%d]\n", (extent_base + extent_offset),
rc);
ecryptfs_printk(KERN_DEBUG, "First 8 bytes after "
"decryption:\n");
ecryptfs_dump_hex((char *)(page_address(page)
+ (extent_offset
* crypt_stat->extent_size)), 8);
}
out:
return rc;
}
/**
* ecryptfs_decrypt_page
* @file: The ecryptfs file
* @page: The page in ecryptfs to decrypt
* @page: Page mapped from the eCryptfs inode for the file; data read
* and decrypted from the lower file will be written into this
* page
*
* Decrypt an eCryptfs page. This is done on a per-extent basis. Note
* that eCryptfs pages may straddle the lower pages -- for instance,
@ -620,103 +697,69 @@ int ecryptfs_encrypt_page(struct ecryptfs_page_crypt_context *ctx)
*
* Returns zero on success; negative on error
*/
int ecryptfs_decrypt_page(struct file *file, struct page *page)
int ecryptfs_decrypt_page(struct page *page)
{
char extent_iv[ECRYPTFS_MAX_IV_BYTES];
unsigned long base_extent;
unsigned long extent_offset = 0;
unsigned long lower_page_idx = 0;
unsigned long prior_lower_page_idx = 0;
struct page *lower_page;
char *lower_page_virt = NULL;
struct inode *lower_inode;
struct inode *ecryptfs_inode;
struct ecryptfs_crypt_stat *crypt_stat;
char *enc_extent_virt = NULL;
struct page *enc_extent_page;
unsigned long extent_offset;
int rc = 0;
int byte_offset;
int num_extents_per_page;
int page_state;
crypt_stat = &(ecryptfs_inode_to_private(
page->mapping->host)->crypt_stat);
lower_inode = ecryptfs_inode_to_lower(page->mapping->host);
ecryptfs_inode = page->mapping->host;
crypt_stat =
&(ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat);
if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
rc = ecryptfs_do_readpage(file, page, page->index);
rc = ecryptfs_read_lower_page_segment(page, page->index, 0,
PAGE_CACHE_SIZE,
ecryptfs_inode);
if (rc)
ecryptfs_printk(KERN_ERR, "Error attempting to copy "
"page at index [0x%.16x]\n",
printk(KERN_ERR "%s: Error attempting to copy "
"page at index [%ld]\n", __FUNCTION__,
page->index);
goto out;
goto out_clear_uptodate;
}
num_extents_per_page = PAGE_CACHE_SIZE / crypt_stat->extent_size;
base_extent = (page->index * num_extents_per_page);
lower_page_virt = kmem_cache_alloc(ecryptfs_lower_page_cache,
GFP_KERNEL);
if (!lower_page_virt) {
enc_extent_virt = kmalloc(PAGE_CACHE_SIZE, GFP_USER);
if (!enc_extent_virt) {
rc = -ENOMEM;
ecryptfs_printk(KERN_ERR, "Error getting page for encrypted "
"lower page(s)\n");
goto out;
ecryptfs_printk(KERN_ERR, "Error allocating memory for "
"encrypted extent\n");
goto out_clear_uptodate;
}
lower_page = virt_to_page(lower_page_virt);
page_state = ECRYPTFS_PAGE_STATE_UNREAD;
while (extent_offset < num_extents_per_page) {
ecryptfs_extent_to_lwr_pg_idx_and_offset(
&lower_page_idx, &byte_offset, crypt_stat,
(base_extent + extent_offset));
if (prior_lower_page_idx != lower_page_idx
|| page_state == ECRYPTFS_PAGE_STATE_UNREAD) {
rc = ecryptfs_do_readpage(file, lower_page,
lower_page_idx);
if (rc) {
ecryptfs_printk(KERN_ERR, "Error reading "
"lower encrypted page; rc = "
"[%d]\n", rc);
goto out;
}
prior_lower_page_idx = lower_page_idx;
page_state = ECRYPTFS_PAGE_STATE_READ;
}
rc = ecryptfs_derive_iv(extent_iv, crypt_stat,
(base_extent + extent_offset));
if (rc) {
ecryptfs_printk(KERN_ERR, "Error attempting to "
"derive IV for extent [0x%.16x]; rc = "
"[%d]\n",
(base_extent + extent_offset), rc);
goto out;
}
if (unlikely(ecryptfs_verbosity > 0)) {
ecryptfs_printk(KERN_DEBUG, "Decrypting extent "
"with iv:\n");
ecryptfs_dump_hex(extent_iv, crypt_stat->iv_bytes);
ecryptfs_printk(KERN_DEBUG, "First 8 bytes before "
"decryption:\n");
ecryptfs_dump_hex((lower_page_virt + byte_offset), 8);
}
rc = ecryptfs_decrypt_page_offset(crypt_stat, page,
(extent_offset
* crypt_stat->extent_size),
lower_page, byte_offset,
enc_extent_page = virt_to_page(enc_extent_virt);
for (extent_offset = 0;
extent_offset < (PAGE_CACHE_SIZE / crypt_stat->extent_size);
extent_offset++) {
loff_t offset;
ecryptfs_lower_offset_for_extent(
&offset, ((page->index * (PAGE_CACHE_SIZE
/ crypt_stat->extent_size))
+ extent_offset), crypt_stat);
rc = ecryptfs_read_lower(enc_extent_virt, offset,
crypt_stat->extent_size,
extent_iv);
if (rc != crypt_stat->extent_size) {
ecryptfs_printk(KERN_ERR, "Error attempting to "
"decrypt extent [0x%.16x]\n",
(base_extent + extent_offset));
goto out;
ecryptfs_inode);
if (rc) {
ecryptfs_printk(KERN_ERR, "Error attempting "
"to read lower page; rc = [%d]"
"\n", rc);
goto out_clear_uptodate;
}
rc = 0;
if (unlikely(ecryptfs_verbosity > 0)) {
ecryptfs_printk(KERN_DEBUG, "First 8 bytes after "
"decryption:\n");
ecryptfs_dump_hex((char *)(page_address(page)
+ byte_offset), 8);
rc = ecryptfs_decrypt_extent(page, crypt_stat, enc_extent_page,
extent_offset);
if (rc) {
printk(KERN_ERR "%s: Error encrypting extent; "
"rc = [%d]\n", __FUNCTION__, rc);
goto out_clear_uptodate;
}
extent_offset++;
}
SetPageUptodate(page);
goto out;
out_clear_uptodate:
ClearPageUptodate(page);
out:
if (lower_page_virt)
kmem_cache_free(ecryptfs_lower_page_cache, lower_page_virt);
kfree(enc_extent_virt);
return rc;
}

14
fs/ecryptfs/ecryptfs_kernel.h
View file

@ -552,13 +552,7 @@ void ecryptfs_destroy_crypt_stat(struct ecryptfs_crypt_stat *crypt_stat);
void ecryptfs_destroy_mount_crypt_stat(
struct ecryptfs_mount_crypt_stat *mount_crypt_stat);
int ecryptfs_init_crypt_ctx(struct ecryptfs_crypt_stat *crypt_stat);
#define ECRYPTFS_LOWER_I_MUTEX_NOT_HELD 0
#define ECRYPTFS_LOWER_I_MUTEX_HELD 1
int ecryptfs_write_inode_size_to_metadata(struct file *lower_file,
struct inode *lower_inode,
struct inode *inode,
struct dentry *ecryptfs_dentry,
int lower_i_mutex_held);
int ecryptfs_write_inode_size_to_metadata(struct inode *ecryptefs_inode);
int ecryptfs_get_lower_page(struct page **lower_page, struct inode *lower_inode,
struct file *lower_file,
unsigned long lower_page_index, int byte_offset,
@ -574,8 +568,8 @@ int ecryptfs_do_readpage(struct file *file, struct page *page,
int ecryptfs_writepage_and_release_lower_page(struct page *lower_page,
struct inode *lower_inode,
struct writeback_control *wbc);
int ecryptfs_encrypt_page(struct ecryptfs_page_crypt_context *ctx);
int ecryptfs_decrypt_page(struct file *file, struct page *page);
int ecryptfs_encrypt_page(struct page *page);
int ecryptfs_decrypt_page(struct page *page);
int ecryptfs_write_metadata(struct dentry *ecryptfs_dentry,
struct file *lower_file);
int ecryptfs_read_metadata(struct dentry *ecryptfs_dentry,
@ -655,6 +649,8 @@ int ecryptfs_keyring_auth_tok_for_sig(struct key **auth_tok_key,
char *sig);
int ecryptfs_write_zeros(struct file *file, pgoff_t index, int start,
int num_zeros);
void ecryptfs_lower_offset_for_extent(loff_t *offset, loff_t extent_num,
struct ecryptfs_crypt_stat *crypt_stat);
int ecryptfs_write_lower(struct inode *ecryptfs_inode, char *data,
loff_t offset, size_t size);
int ecryptfs_write_lower_page_segment(struct inode *ecryptfs_inode,

12
fs/ecryptfs/inode.c
View file

@ -168,9 +168,7 @@ static int grow_file(struct dentry *ecryptfs_dentry, struct file *lower_file,
goto out;
}
i_size_write(inode, 0);
rc = ecryptfs_write_inode_size_to_metadata(lower_file, lower_inode,
inode, ecryptfs_dentry,
ECRYPTFS_LOWER_I_MUTEX_NOT_HELD);
rc = ecryptfs_write_inode_size_to_metadata(inode);
ecryptfs_inode_to_private(inode)->crypt_stat.flags |= ECRYPTFS_NEW_FILE;
out:
return rc;
@ -798,9 +796,7 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
goto out_fput;
}
i_size_write(inode, new_length);
rc = ecryptfs_write_inode_size_to_metadata(
lower_file, lower_dentry->d_inode, inode, dentry,
ECRYPTFS_LOWER_I_MUTEX_NOT_HELD);
rc = ecryptfs_write_inode_size_to_metadata(inode);
if (rc) {
printk(KERN_ERR "Problem with "
"ecryptfs_write_inode_size_to_metadata; "
@ -829,9 +825,7 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
}
}
vmtruncate(inode, new_length);
rc = ecryptfs_write_inode_size_to_metadata(
lower_file, lower_dentry->d_inode, inode, dentry,
ECRYPTFS_LOWER_I_MUTEX_NOT_HELD);
rc = ecryptfs_write_inode_size_to_metadata(inode);
if (rc) {
printk(KERN_ERR "Problem with "
"ecryptfs_write_inode_size_to_metadata; "

129
fs/ecryptfs/mmap.c
View file

@ -171,13 +171,9 @@ int ecryptfs_fill_zeros(struct file *file, loff_t new_length)
*/
static int ecryptfs_writepage(struct page *page, struct writeback_control *wbc)
{
struct ecryptfs_page_crypt_context ctx;
int rc;
ctx.page = page;
ctx.mode = ECRYPTFS_WRITEPAGE_MODE;
ctx.param.wbc = wbc;
rc = ecryptfs_encrypt_page(&ctx);
rc = ecryptfs_encrypt_page(page);
if (rc) {
ecryptfs_printk(KERN_WARNING, "Error encrypting "
"page (upper index [0x%.16x])\n", page->index);
@ -341,7 +337,7 @@ static int ecryptfs_readpage(struct file *file, struct page *page)
}
}
} else {
rc = ecryptfs_decrypt_page(file, page);
rc = ecryptfs_decrypt_page(page);
if (rc) {
ecryptfs_printk(KERN_ERR, "Error decrypting page; "
"rc = [%d]\n", rc);
@ -459,58 +455,48 @@ static void ecryptfs_release_lower_page(struct page *lower_page)
*
* Returns zero on success; non-zero on error.
*/
static int ecryptfs_write_inode_size_to_header(struct file *lower_file,
struct inode *lower_inode,
struct inode *inode)
static int ecryptfs_write_inode_size_to_header(struct inode *ecryptfs_inode)
{
int rc = 0;
struct page *header_page;
char *header_virt;
const struct address_space_operations *lower_a_ops;
u64 file_size;
char *file_size_virt;
int rc;
header_page = grab_cache_page(lower_inode->i_mapping, 0);
if (!header_page) {
ecryptfs_printk(KERN_ERR, "grab_cache_page for "
"lower_page_index 0 failed\n");
rc = -EINVAL;
file_size_virt = kmalloc(sizeof(u64), GFP_KERNEL);
if (!file_size_virt) {
rc = -ENOMEM;
goto out;
}
lower_a_ops = lower_inode->i_mapping->a_ops;
rc = lower_a_ops->prepare_write(lower_file, header_page, 0, 8);
if (rc) {
ecryptfs_release_lower_page(header_page);
goto out;
}
file_size = (u64)i_size_read(inode);
ecryptfs_printk(KERN_DEBUG, "Writing size: [0x%.16x]\n", file_size);
file_size = (u64)i_size_read(ecryptfs_inode);
file_size = cpu_to_be64(file_size);
header_virt = kmap_atomic(header_page, KM_USER0);
memcpy(header_virt, &file_size, sizeof(u64));
kunmap_atomic(header_virt, KM_USER0);
flush_dcache_page(header_page);
rc = lower_a_ops->commit_write(lower_file, header_page, 0, 8);
if (rc < 0)
ecryptfs_printk(KERN_ERR, "Error commiting header page "
"write\n");
ecryptfs_release_lower_page(header_page);
lower_inode->i_mtime = lower_inode->i_ctime = CURRENT_TIME;
mark_inode_dirty_sync(inode);
memcpy(file_size_virt, &file_size, sizeof(u64));
rc = ecryptfs_write_lower(ecryptfs_inode, file_size_virt, 0,
sizeof(u64));
kfree(file_size_virt);
if (rc)
printk(KERN_ERR "%s: Error writing file size to header; "
"rc = [%d]\n", __FUNCTION__, rc);
out:
return rc;
}
static int ecryptfs_write_inode_size_to_xattr(struct inode *lower_inode,
struct inode *inode,
struct dentry *ecryptfs_dentry,
int lower_i_mutex_held)
struct kmem_cache *ecryptfs_xattr_cache;
static int ecryptfs_write_inode_size_to_xattr(struct inode *ecryptfs_inode)
{
ssize_t size;
void *xattr_virt;
struct dentry *lower_dentry;
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) {
printk(KERN_WARNING
"No support for setting xattr in lower filesystem\n");
rc = -ENOSYS;
goto out;
}
xattr_virt = kmem_cache_alloc(ecryptfs_xattr_cache, GFP_KERNEL);
if (!xattr_virt) {
printk(KERN_ERR "Out of memory whilst attempting to write "
@ -518,35 +504,17 @@ static int ecryptfs_write_inode_size_to_xattr(struct inode *lower_inode,
rc = -ENOMEM;
goto out;
}
lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
if (!lower_dentry->d_inode->i_op->getxattr ||
!lower_dentry->d_inode->i_op->setxattr) {
printk(KERN_WARNING
"No support for setting xattr in lower filesystem\n");
rc = -ENOSYS;
kmem_cache_free(ecryptfs_xattr_cache, xattr_virt);
goto out;
}
if (!lower_i_mutex_held)
mutex_lock(&lower_dentry->d_inode->i_mutex);
size = lower_dentry->d_inode->i_op->getxattr(lower_dentry,
ECRYPTFS_XATTR_NAME,
xattr_virt,
PAGE_CACHE_SIZE);
if (!lower_i_mutex_held)
mutex_unlock(&lower_dentry->d_inode->i_mutex);
mutex_lock(&lower_inode->i_mutex);
size = lower_inode->i_op->getxattr(lower_dentry, ECRYPTFS_XATTR_NAME,
xattr_virt, PAGE_CACHE_SIZE);
if (size < 0)
size = 8;
file_size = (u64)i_size_read(inode);
file_size = (u64)i_size_read(ecryptfs_inode);
file_size = cpu_to_be64(file_size);
memcpy(xattr_virt, &file_size, sizeof(u64));
if (!lower_i_mutex_held)
mutex_lock(&lower_dentry->d_inode->i_mutex);
rc = lower_dentry->d_inode->i_op->setxattr(lower_dentry,
ECRYPTFS_XATTR_NAME,
rc = lower_inode->i_op->setxattr(lower_dentry, ECRYPTFS_XATTR_NAME,
xattr_virt, size, 0);
if (!lower_i_mutex_held)
mutex_unlock(&lower_dentry->d_inode->i_mutex);
mutex_unlock(&lower_inode->i_mutex);
if (rc)
printk(KERN_ERR "Error whilst attempting to write inode size "
"to lower file xattr; rc = [%d]\n", rc);
@ -555,24 +523,15 @@ static int ecryptfs_write_inode_size_to_xattr(struct inode *lower_inode,
return rc;
}
int
ecryptfs_write_inode_size_to_metadata(struct file *lower_file,
struct inode *lower_inode,
struct inode *inode,
struct dentry *ecryptfs_dentry,
int lower_i_mutex_held)
int ecryptfs_write_inode_size_to_metadata(struct inode *ecryptfs_inode)
{
struct ecryptfs_crypt_stat *crypt_stat;
crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
crypt_stat = &ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat;
if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR)
return ecryptfs_write_inode_size_to_xattr(lower_inode, inode,
ecryptfs_dentry,
lower_i_mutex_held);
return ecryptfs_write_inode_size_to_xattr(ecryptfs_inode);
else
return ecryptfs_write_inode_size_to_header(lower_file,
lower_inode,
inode);
return ecryptfs_write_inode_size_to_header(ecryptfs_inode);
}
int ecryptfs_get_lower_page(struct page **lower_page, struct inode *lower_inode,
@ -659,8 +618,6 @@ int ecryptfs_copy_page_to_lower(struct page *page, struct inode *lower_inode,
return rc;
}
struct kmem_cache *ecryptfs_xattr_cache;
/**
* ecryptfs_commit_write
* @file: The eCryptfs file object
@ -675,7 +632,6 @@ struct kmem_cache *ecryptfs_xattr_cache;
static int ecryptfs_commit_write(struct file *file, struct page *page,
unsigned from, unsigned to)
{
struct ecryptfs_page_crypt_context ctx;
loff_t pos;
struct inode *inode;
struct inode *lower_inode;
@ -705,10 +661,7 @@ static int ecryptfs_commit_write(struct file *file, struct page *page,
page->index);
goto out;
}
ctx.page = page;
ctx.mode = ECRYPTFS_PREPARE_COMMIT_MODE;
ctx.param.lower_file = lower_file;
rc = ecryptfs_encrypt_page(&ctx);
rc = ecryptfs_encrypt_page(page);
if (rc) {
ecryptfs_printk(KERN_WARNING, "Error encrypting page (upper "
"index [0x%.16x])\n", page->index);
@ -721,9 +674,7 @@ static int ecryptfs_commit_write(struct file *file, struct page *page,
ecryptfs_printk(KERN_DEBUG, "Expanded file size to "
"[0x%.16x]\n", i_size_read(inode));
}
rc = ecryptfs_write_inode_size_to_metadata(lower_file, lower_inode,
inode, file->f_dentry,
ECRYPTFS_LOWER_I_MUTEX_HELD);
rc = ecryptfs_write_inode_size_to_metadata(inode);
if (rc)
printk(KERN_ERR "Error writing inode size to metadata; "
"rc = [%d]\n", rc);

12
fs/ecryptfs/read_write.c
View file

@ -154,8 +154,8 @@ int ecryptfs_write(struct file *ecryptfs_file, char *data, loff_t offset,
/* Read in the page from the lower
* into the eCryptfs inode page cache,
* decrypting */
if ((rc = ecryptfs_decrypt_page(NULL, /* placeholder for git-bisect */
ecryptfs_page))) {
rc = ecryptfs_decrypt_page(ecryptfs_page);
if (rc) {
printk(KERN_ERR "%s: Error decrypting "
"page; rc = [%d]\n",
__FUNCTION__, rc);
@ -178,7 +178,7 @@ int ecryptfs_write(struct file *ecryptfs_file, char *data, loff_t offset,
}
kunmap_atomic(ecryptfs_page_virt, KM_USER0);
flush_dcache_page(ecryptfs_page);
rc = ecryptfs_encrypt_page(NULL /* placeholder for git-bisect */);
rc = ecryptfs_encrypt_page(ecryptfs_page);
if (rc) {
printk(KERN_ERR "%s: Error encrypting "
"page; rc = [%d]\n", __FUNCTION__, rc);
@ -190,8 +190,8 @@ int ecryptfs_write(struct file *ecryptfs_file, char *data, loff_t offset,
}
if ((offset + size) > ecryptfs_file_size) {
i_size_write(ecryptfs_file->f_dentry->d_inode, (offset + size));
rc = ecryptfs_write_inode_size_to_metadata(NULL, NULL, NULL,
NULL, 0); /* placeholders for git-bisect */
rc = ecryptfs_write_inode_size_to_metadata(
ecryptfs_file->f_dentry->d_inode);
if (rc) {
printk(KERN_ERR "Problem with "
"ecryptfs_write_inode_size_to_metadata; "
@ -338,7 +338,7 @@ int ecryptfs_read(char *data, loff_t offset, size_t size,
ecryptfs_page_idx, rc);
goto out;
}
rc = ecryptfs_decrypt_page(NULL /* placeholder for git-bisect */, ecryptfs_page);
rc = ecryptfs_decrypt_page(ecryptfs_page);
if (rc) {
printk(KERN_ERR "%s: Error decrypting "
"page; rc = [%d]\n", __FUNCTION__, rc);