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ext4 crypto: insert encrypted filenames into a leaf directory block

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Signed-off-by: Uday Savagaonkar <savagaon@google.com>
Signed-off-by: Ildar Muslukhov <ildarm@google.com>
Signed-off-by: Michael Halcrow <mhalcrow@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
This commit is contained in:
Michael Halcrow 2015-04-12 00:56:28 -04:00 committed by Theodore Ts'o
parent 2f61830ae3
commit 4bdfc873ba
3 changed files with 79 additions and 13 deletions
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4
fs/ext4/ext4.h
View File

@ -2151,9 +2151,11 @@ extern int ext4_find_dest_de(struct inode *dir, struct inode *inode,
void *buf, int buf_size,
const char *name, int namelen,
struct ext4_dir_entry_2 **dest_de);
void ext4_insert_dentry(struct inode *inode,
int ext4_insert_dentry(struct inode *dir,
struct inode *inode,
struct ext4_dir_entry_2 *de,
int buf_size,
const struct qstr *iname,
const char *name, int namelen);
static inline void ext4_update_dx_flag(struct inode *inode)
{

7
fs/ext4/inline.c
View File

@ -11,11 +11,13 @@
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/fiemap.h>
#include "ext4_jbd2.h"
#include "ext4.h"
#include "xattr.h"
#include "truncate.h"
#include <linux/fiemap.h>
#define EXT4_XATTR_SYSTEM_DATA "data"
#define EXT4_MIN_INLINE_DATA_SIZE ((sizeof(__le32) * EXT4_N_BLOCKS))
@ -1014,7 +1016,8 @@ static int ext4_add_dirent_to_inline(handle_t *handle,
err = ext4_journal_get_write_access(handle, iloc->bh);
if (err)
return err;
ext4_insert_dentry(inode, de, inline_size, name, namelen);
ext4_insert_dentry(dir, inode, de, inline_size, &dentry->d_name,
name, namelen);
ext4_show_inline_dir(dir, iloc->bh, inline_start, inline_size);

81
fs/ext4/namei.c
View File

@ -1665,19 +1665,49 @@ int ext4_find_dest_de(struct inode *dir, struct inode *inode,
return 0;
}
void ext4_insert_dentry(struct inode *inode,
struct ext4_dir_entry_2 *de,
int buf_size,
const char *name, int namelen)
int ext4_insert_dentry(struct inode *dir,
struct inode *inode,
struct ext4_dir_entry_2 *de,
int buf_size,
const struct qstr *iname,
const char *name, int namelen)
{
int nlen, rlen;
struct ext4_fname_crypto_ctx *ctx = NULL;
struct ext4_str fname_crypto_str = {.name = NULL, .len = 0};
struct ext4_str tmp_str;
int res;
ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN);
if (IS_ERR(ctx))
return -EIO;
/* By default, the input name would be written to the disk */
tmp_str.name = (unsigned char *)name;
tmp_str.len = namelen;
if (ctx != NULL) {
/* Directory is encrypted */
res = ext4_fname_crypto_alloc_buffer(ctx, EXT4_NAME_LEN,
&fname_crypto_str);
if (res < 0) {
ext4_put_fname_crypto_ctx(&ctx);
return -ENOMEM;
}
res = ext4_fname_usr_to_disk(ctx, iname, &fname_crypto_str);
if (res < 0) {
ext4_put_fname_crypto_ctx(&ctx);
ext4_fname_crypto_free_buffer(&fname_crypto_str);
return res;
}
tmp_str.name = fname_crypto_str.name;
tmp_str.len = fname_crypto_str.len;
}
nlen = EXT4_DIR_REC_LEN(de->name_len);
rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
if (de->inode) {
struct ext4_dir_entry_2 *de1 =
(struct ext4_dir_entry_2 *)((char *)de + nlen);
(struct ext4_dir_entry_2 *)((char *)de + nlen);
de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, buf_size);
de->rec_len = ext4_rec_len_to_disk(nlen, buf_size);
de = de1;
@ -1685,9 +1715,14 @@ void ext4_insert_dentry(struct inode *inode,
de->file_type = EXT4_FT_UNKNOWN;
de->inode = cpu_to_le32(inode->i_ino);
ext4_set_de_type(inode->i_sb, de, inode->i_mode);
de->name_len = namelen;
memcpy(de->name, name, namelen);
de->name_len = tmp_str.len;
memcpy(de->name, tmp_str.name, tmp_str.len);
ext4_put_fname_crypto_ctx(&ctx);
ext4_fname_crypto_free_buffer(&fname_crypto_str);
return 0;
}
/*
* Add a new entry into a directory (leaf) block. If de is non-NULL,
* it points to a directory entry which is guaranteed to be large
@ -1724,8 +1759,12 @@ static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
return err;
}
/* By now the buffer is marked for journaling */
ext4_insert_dentry(inode, de, blocksize, name, namelen);
/* By now the buffer is marked for journaling. Due to crypto operations,
* the following function call may fail */
err = ext4_insert_dentry(dir, inode, de, blocksize, &dentry->d_name,
name, namelen);
if (err < 0)
return err;
/*
* XXX shouldn't update any times until successful
@ -1757,8 +1796,13 @@ static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
struct inode *inode, struct buffer_head *bh)
{
struct inode *dir = dentry->d_parent->d_inode;
#ifdef CONFIG_EXT4_FS_ENCRYPTION
struct ext4_fname_crypto_ctx *ctx = NULL;
int res;
#else
const char *name = dentry->d_name.name;
int namelen = dentry->d_name.len;
#endif
struct buffer_head *bh2;
struct dx_root *root;
struct dx_frame frames[2], *frame;
@ -1772,7 +1816,13 @@ static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
struct dx_hash_info hinfo;
ext4_lblk_t block;
struct fake_dirent *fde;
int csum_size = 0;
int csum_size = 0;
#ifdef CONFIG_EXT4_FS_ENCRYPTION
ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN);
if (IS_ERR(ctx))
return PTR_ERR(ctx);
#endif
if (ext4_has_metadata_csum(inode->i_sb))
csum_size = sizeof(struct ext4_dir_entry_tail);
@ -1839,7 +1889,18 @@ static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
if (hinfo.hash_version <= DX_HASH_TEA)
hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
#ifdef CONFIG_EXT4_FS_ENCRYPTION
res = ext4_fname_usr_to_hash(ctx, &dentry->d_name, &hinfo);
if (res < 0) {
ext4_put_fname_crypto_ctx(&ctx);
ext4_mark_inode_dirty(handle, dir);
brelse(bh);
return res;
}
ext4_put_fname_crypto_ctx(&ctx);
#else
ext4fs_dirhash(name, namelen, &hinfo);
#endif
memset(frames, 0, sizeof(frames));
frame = frames;
frame->entries = entries;