[PATCH 14/18] f2fs crypto: add filename encryption for f2fs_lookup

Jaegeuk Kim
2015-05-09T04:23:41Z

This patch implements filename encryption support for f2fs_lookup.

Note that, f2fs_find_entry should be outside of f2fs_(un)lock_op().

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
fs/f2fs/dir.c | 79 ++++++++++++++++++++++++++++++++------------------------
fs/f2fs/f2fs.h | 9 ++++---
fs/f2fs/inline.c | 9 ++++---
3 files changed, 56 insertions(+), 41 deletions(-)

diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c
index ab6455d..5e10d9d 100644
--- a/fs/f2fs/dir.c
+++ b/fs/f2fs/dir.c
@@ -76,20 +76,10 @@ static unsigned long dir_block_index(unsigned int level,
return bidx;
}

-static bool early_match_name(size_t namelen, f2fs_hash_t namehash,
- struct f2fs_dir_entry *de)
-{
- if (le16_to_cpu(de->name_len) != namelen)
- return false;
-
- if (de->hash_code != namehash)
- return false;
-
- return true;
-}
-
static struct f2fs_dir_entry *find_in_block(struct page *dentry_page,
- struct qstr *name, int *max_slots,
+ struct f2fs_filename *fname,
+ f2fs_hash_t namehash,
+ int *max_slots,
struct page **res_page)
{
struct f2fs_dentry_block *dentry_blk;
@@ -99,8 +89,7 @@ static struct f2fs_dir_entry *find_in_block(struct page *dentry_page,
dentry_blk = (struct f2fs_dentry_block *)kmap(dentry_page);

make_dentry_ptr(NULL, &d, (void *)dentry_blk, 1);
- de = find_target_dentry(name, max_slots, &d);
-
+ de = find_target_dentry(fname, namehash, max_slots, &d);
if (de)
*res_page = dentry_page;
else
@@ -114,13 +103,15 @@ static struct f2fs_dir_entry *find_in_block(struct page *dentry_page,
return de;
}

-struct f2fs_dir_entry *find_target_dentry(struct qstr *name, int *max_slots,
- struct f2fs_dentry_ptr *d)
+struct f2fs_dir_entry *find_target_dentry(struct f2fs_filename *fname,
+ f2fs_hash_t namehash, int *max_slots,
+ struct f2fs_dentry_ptr *d)
{
struct f2fs_dir_entry *de;
unsigned long bit_pos = 0;
- f2fs_hash_t namehash = f2fs_dentry_hash(name);
int max_len = 0;
+ struct f2fs_str de_name = FSTR_INIT(NULL, 0);
+ struct f2fs_str *name = &fname->disk_name;

if (max_slots)
*max_slots = 0;
@@ -132,8 +123,18 @@ struct f2fs_dir_entry *find_target_dentry(struct qstr *name, int *max_slots,
}

de = &d->dentry[bit_pos];
- if (early_match_name(name->len, namehash, de) &&
- !memcmp(d->filename[bit_pos], name->name, name->len))
+
+ /* encrypted case */
+ de_name.name = d->filename[bit_pos];
+ de_name.len = le16_to_cpu(de->name_len);
+
+ /* show encrypted name */
+ if (fname->hash) {
+ if (de->hash_code == fname->hash)
+ goto found;
+ } else if (de_name.len == name->len &&
+ de->hash_code == namehash &&
+ !memcmp(de_name.name, name->name, name->len))
goto found;

if (max_slots && max_len > *max_slots)
@@ -155,16 +156,21 @@ found:
}

static struct f2fs_dir_entry *find_in_level(struct inode *dir,
- unsigned int level, struct qstr *name,
- f2fs_hash_t namehash, struct page **res_page)
+ unsigned int level,
+ struct f2fs_filename *fname,
+ struct page **res_page)
{
- int s = GET_DENTRY_SLOTS(name->len);
+ struct qstr name = FSTR_TO_QSTR(&fname->disk_name);
+ int s = GET_DENTRY_SLOTS(name.len);
unsigned int nbucket, nblock;
unsigned int bidx, end_block;
struct page *dentry_page;
struct f2fs_dir_entry *de = NULL;
bool room = false;
int max_slots;
+ f2fs_hash_t namehash;
+
+ namehash = f2fs_dentry_hash(&name);

f2fs_bug_on(F2FS_I_SB(dir), level > MAX_DIR_HASH_DEPTH);

@@ -183,7 +189,8 @@ static struct f2fs_dir_entry *find_in_level(struct inode *dir,
continue;
}

- de = find_in_block(dentry_page, name, &max_slots, res_page);
+ de = find_in_block(dentry_page, fname, namehash, &max_slots,
+ res_page);
if (de)
break;

@@ -211,30 +218,34 @@ struct f2fs_dir_entry *f2fs_find_entry(struct inode *dir,
{
unsigned long npages = dir_blocks(dir);
struct f2fs_dir_entry *de = NULL;
- f2fs_hash_t name_hash;
unsigned int max_depth;
unsigned int level;
+ struct f2fs_filename fname;
+ int err;

*res_page = NULL;

- if (f2fs_has_inline_dentry(dir))
- return find_in_inline_dir(dir, child, res_page);
+ err = f2fs_fname_setup_filename(dir, child, 1, &fname);
+ if (err)
+ return NULL;
+
+ if (f2fs_has_inline_dentry(dir)) {
+ de = find_in_inline_dir(dir, &fname, res_page);
+ goto out;
+ }

if (npages == 0)
- return NULL;
+ goto out;

- name_hash = f2fs_dentry_hash(child);
max_depth = F2FS_I(dir)->i_current_depth;

for (level = 0; level < max_depth; level++) {
- de = find_in_level(dir, level, child, name_hash, res_page);
+ de = find_in_level(dir, level, &fname, res_page);
if (de)
break;
}
- if (!de && F2FS_I(dir)->chash != name_hash) {
- F2FS_I(dir)->chash = name_hash;
- F2FS_I(dir)->clevel = level - 1;
- }
+out:
+ f2fs_fname_free_filename(&fname);
return de;
}

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 963616f..6898331 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1584,8 +1584,9 @@ struct dentry *f2fs_get_parent(struct dentry *child);
*/
extern unsigned char f2fs_filetype_table[F2FS_FT_MAX];
void set_de_type(struct f2fs_dir_entry *, umode_t);
-struct f2fs_dir_entry *find_target_dentry(struct qstr *, int *,
- struct f2fs_dentry_ptr *);
+
+struct f2fs_dir_entry *find_target_dentry(struct f2fs_filename *,
+ f2fs_hash_t, int *, struct f2fs_dentry_ptr *);
bool f2fs_fill_dentries(struct dir_context *, struct f2fs_dentry_ptr *,
unsigned int, struct f2fs_str *);
void do_make_empty_dir(struct inode *, struct inode *,
@@ -1931,8 +1932,8 @@ int f2fs_convert_inline_page(struct dnode_of_data *, struct page *);
int f2fs_convert_inline_inode(struct inode *);
int f2fs_write_inline_data(struct inode *, struct page *);
bool recover_inline_data(struct inode *, struct page *);
-struct f2fs_dir_entry *find_in_inline_dir(struct inode *, struct qstr *,
- struct page **);
+struct f2fs_dir_entry *find_in_inline_dir(struct inode *,
+ struct f2fs_filename *, struct page **);
struct f2fs_dir_entry *f2fs_parent_inline_dir(struct inode *, struct page **);
int make_empty_inline_dir(struct inode *inode, struct inode *, struct page *);
int f2fs_add_inline_entry(struct inode *, const struct qstr *, struct inode *,
diff --git a/fs/f2fs/inline.c b/fs/f2fs/inline.c
index dd51d3f..38e75fb 100644
--- a/fs/f2fs/inline.c
+++ b/fs/f2fs/inline.c
@@ -284,23 +284,26 @@ process_inline:
}

struct f2fs_dir_entry *find_in_inline_dir(struct inode *dir,
- struct qstr *name, struct page **res_page)
+ struct f2fs_filename *fname, struct page **res_page)
{
struct f2fs_sb_info *sbi = F2FS_SB(dir->i_sb);
struct f2fs_inline_dentry *inline_dentry;
+ struct qstr name = FSTR_TO_QSTR(&fname->disk_name);
struct f2fs_dir_entry *de;
struct f2fs_dentry_ptr d;
struct page *ipage;
+ f2fs_hash_t namehash;

ipage = get_node_page(sbi, dir->i_ino);
if (IS_ERR(ipage))
return NULL;

+ namehash = f2fs_dentry_hash(&name);
+
inline_dentry = inline_data_addr(ipage);

make_dentry_ptr(NULL, &d, (void *)inline_dentry, 2);
- de = find_target_dentry(name, NULL, &d);
-
+ de = find_target_dentry(fname, namehash, NULL, &d);
unlock_page(ipage);
if (de)
*res_page = ipage;
--
2.1.1