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Commit 4bdfc873 authored by Michael Halcrow's avatar Michael Halcrow Committed by Theodore Ts'o
Browse files

ext4 crypto: insert encrypted filenames into a leaf directory block 



Signed-off-by: default avatarUday Savagaonkar <savagaon@google.com>
Signed-off-by: default avatarIldar Muslukhov <ildarm@google.com>
Signed-off-by: default avatarMichael Halcrow <mhalcrow@google.com>
Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
parent 2f61830a

fs/ext4/ext4.h

+3 −1
Original line number Diff line number Diff line
@@ -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)

{

fs/ext4/inline.c

+5 −2
Original line number Diff line number Diff line
@@ -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);

fs/ext4/namei.c

+71 −10
Original line number Diff line number Diff line
@@ -1665,13 +1665,43 @@ int ext4_find_dest_de(struct inode *dir, struct inode *inode, 
	return 0;

}



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)

{



	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);
@@ -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;
@@ -1774,6 +1818,12 @@ static int make_indexed_dir(handle_t *handle, struct dentry *dentry, 
	struct fake_dirent *fde;

	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;