From: Michael Halcrow <mhalcrow@xxxxxxxxxx>
Modifies htree_dirblock_to_tree, dx_make_map, ext4_match search_dir,
and ext4_find_dest_de to support fname crypto. Filename encryption
feature is not yet enabled at this patch.
Change-Id: I0170e0dac991a831f66a638a3bb5340d8dc775ae
Signed-off-by: Uday Savagaonkar <savagaon@xxxxxxxxxx>
Signed-off-by: Ildar Muslukhov <ildarm@xxxxxxxxxx>
Signed-off-by: Michael Halcrow <mhalcrow@xxxxxxxxxx>
Signed-off-by: Theodore Ts'o <tytso@xxxxxxx>
---
fs/ext4/namei.c | 253 ++++++++++++++++++++++++++++++++++++++++++++++----------
1 file changed, 209 insertions(+), 44 deletions(-)
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 4fccb76..80a3979 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -256,8 +256,9 @@ static struct dx_frame *dx_probe(const struct qstr *d_name,
struct dx_hash_info *hinfo,
struct dx_frame *frame);
static void dx_release(struct dx_frame *frames);
-static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize,
- struct dx_hash_info *hinfo, struct dx_map_entry map[]);
+static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de,
+ unsigned blocksize, struct dx_hash_info *hinfo,
+ struct dx_map_entry map[]);
static void dx_sort_map(struct dx_map_entry *map, unsigned count);
static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to,
struct dx_map_entry *offsets, int count, unsigned blocksize);
@@ -982,7 +983,8 @@ static int htree_dirblock_to_tree(struct file *dir_file,
struct buffer_head *bh;
struct ext4_dir_entry_2 *de, *top;
int err = 0, count = 0;
- struct ext4_str tmp_str;
+ struct ext4_fname_crypto_ctx *ctx = NULL;
+ struct ext4_str fname_crypto_str = {.name = NULL, .len = 0}, tmp_str;
dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
(unsigned long)block));
@@ -994,6 +996,25 @@ static int htree_dirblock_to_tree(struct file *dir_file,
top = (struct ext4_dir_entry_2 *) ((char *) de +
dir->i_sb->s_blocksize -
EXT4_DIR_REC_LEN(0));
+#ifdef CONFIG_EXT4_FS_ENCRYPTION
+ /* Check if the directory is encrypted */
+ ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN);
+ if (IS_ERR(ctx)) {
+ err = PTR_ERR(ctx);
+ brelse(bh);
+ return err;
+ }
+ if (ctx != NULL) {
+ err = ext4_fname_crypto_alloc_buffer(ctx,
+ &fname_crypto_str.name, &fname_crypto_str.len,
+ EXT4_NAME_LEN);
+ if (err < 0) {
+ ext4_put_fname_crypto_ctx(&ctx);
+ brelse(bh);
+ return err;
+ }
+ }
+#endif
for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) {
if (ext4_check_dir_entry(dir, NULL, de, bh,
bh->b_data, bh->b_size,
@@ -1002,24 +1023,52 @@ static int htree_dirblock_to_tree(struct file *dir_file,
/* silently ignore the rest of the block */
break;
}
+#ifdef CONFIG_EXT4_FS_ENCRYPTION
+ err = ext4_fname_disk_to_hash(ctx, de, hinfo);
+ if (err < 0) {
+ count = err;
+ goto errout;
+ }
+#else
ext4fs_dirhash(de->name, de->name_len, hinfo);
+#endif
if ((hinfo->hash < start_hash) ||
((hinfo->hash == start_hash) &&
(hinfo->minor_hash < start_minor_hash)))
continue;
if (de->inode == 0)
continue;
- tmp_str.name = de->name;
- tmp_str.len = de->name_len;
- err = ext4_htree_store_dirent(dir_file,
- hinfo->hash, hinfo->minor_hash, de, &tmp_str);
+ if (ctx == NULL) {
+ /* Directory is not encrypted */
+ tmp_str.name = de->name;
+ tmp_str.len = de->name_len;
+ err = ext4_htree_store_dirent(dir_file,
+ hinfo->hash, hinfo->minor_hash, de,
+ &tmp_str);
+ } else {
+ /* Directory is encrypted */
+ err = ext4_fname_disk_to_usr(ctx, de,
+ &fname_crypto_str);
+ if (err < 0) {
+ count = err;
+ goto errout;
+ }
+ err = ext4_htree_store_dirent(dir_file,
+ hinfo->hash, hinfo->minor_hash, de,
+ &fname_crypto_str);
+ }
if (err != 0) {
- brelse(bh);
- return err;
+ count = err;
+ goto errout;
}
count++;
}
+errout:
brelse(bh);
+#ifdef CONFIG_EXT4_FS_ENCRYPTION
+ ext4_put_fname_crypto_ctx(&ctx);
+ ext4_fname_crypto_free_buffer((void **)&fname_crypto_str.name);
+#endif
return count;
}
@@ -1152,17 +1201,33 @@ static inline int search_dirblock(struct buffer_head *bh,
* Create map of hash values, offsets, and sizes, stored at end of block.
* Returns number of entries mapped.
*/
-static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize,
- struct dx_hash_info *hinfo,
+static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de,
+ unsigned blocksize, struct dx_hash_info *hinfo,
struct dx_map_entry *map_tail)
{
int count = 0;
char *base = (char *) de;
struct dx_hash_info h = *hinfo;
+#ifdef CONFIG_EXT4_FS_ENCRYPTION
+ struct ext4_fname_crypto_ctx *ctx = NULL;
+ int err;
+
+ ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN);
+ if (IS_ERR(ctx))
+ return PTR_ERR(ctx);
+#endif
while ((char *) de < base + blocksize) {
if (de->name_len && de->inode) {
+#ifdef CONFIG_EXT4_FS_ENCRYPTION
+ err = ext4_fname_disk_to_hash(ctx, de, &h);
+ if (err < 0) {
+ ext4_put_fname_crypto_ctx(&ctx);
+ return err;
+ }
+#else
ext4fs_dirhash(de->name, de->name_len, &h);
+#endif
map_tail--;
map_tail->hash = h.hash;
map_tail->offs = ((char *) de - base)>>2;
@@ -1173,6 +1238,9 @@ static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize,
/* XXX: do we need to check rec_len == 0 case? -Chris */
de = ext4_next_entry(de, blocksize);
}
+#ifdef CONFIG_EXT4_FS_ENCRYPTION
+ ext4_put_fname_crypto_ctx(&ctx);
+#endif
return count;
}
@@ -1223,57 +1291,109 @@ static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
* `len <= EXT4_NAME_LEN' is guaranteed by caller.
* `de != NULL' is guaranteed by caller.
*/
-static inline int ext4_match (int len, const char * const name,
- struct ext4_dir_entry_2 * de)
+static inline int ext4_match(struct ext4_fname_crypto_ctx *ctx,
+ struct ext4_str *fname_crypto_str,
+ int len, const char * const name,
+ struct ext4_dir_entry_2 *de)
{
- if (len != de->name_len)
- return 0;
+ int res;
+
if (!de->inode)
return 0;
- return !memcmp(name, de->name, len);
+
+#ifdef CONFIG_EXT4_FS_ENCRYPTION
+ if (ctx) {
+ /* Directory is encrypted */
+ res = ext4_fname_disk_to_usr(ctx, de, fname_crypto_str);
+ if (res < 0)
+ return res;
+ if (len != res)
+ return 0;
+ res = memcmp(name, fname_crypto_str->name, len);
+ return (res == 0) ? 1 : 0;
+ }
+#endif
+ if (len != de->name_len)
+ return 0;
+ res = memcmp(name, de->name, len);
+ return (res == 0) ? 1 : 0;
}
/*
* Returns 0 if not found, -1 on failure, and 1 on success
*/
-int search_dir(struct buffer_head *bh,
- char *search_buf,
- int buf_size,
- struct inode *dir,
- const struct qstr *d_name,
- unsigned int offset,
- struct ext4_dir_entry_2 **res_dir)
+int search_dir(struct buffer_head *bh, char *search_buf, int buf_size,
+ struct inode *dir, const struct qstr *d_name,
+ unsigned int offset, struct ext4_dir_entry_2 **res_dir)
{
struct ext4_dir_entry_2 * de;
char * dlimit;
int de_len;
const char *name = d_name->name;
int namelen = d_name->len;
+ struct ext4_fname_crypto_ctx *ctx = NULL;
+ struct ext4_str fname_crypto_str = {.name = NULL, .len = 0};
+ int res;
+
+ ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN);
+ if (IS_ERR(ctx))
+ return -1;
+
+ if (ctx != NULL) {
+ /* Allocate buffer to hold maximum name length */
+ res = ext4_fname_crypto_alloc_buffer(ctx,
+ &fname_crypto_str.name,
+ &fname_crypto_str.len,
+ EXT4_NAME_LEN);
+ if (res < 0) {
+ ext4_put_fname_crypto_ctx(&ctx);
+ return -1;
+ }
+ }
de = (struct ext4_dir_entry_2 *)search_buf;
dlimit = search_buf + buf_size;
while ((char *) de < dlimit) {
/* this code is executed quadratically often */
/* do minimal checking `by hand' */
+ if ((char *) de + de->name_len <= dlimit) {
+ res = ext4_match(ctx, &fname_crypto_str, namelen,
+ name, de);
+ if (res < 0) {
+ res = -1;
+ goto return_result;
+ }
+ if (res > 0) {
+ /* found a match - just to be sure, do
+ * a full check */
+ if (ext4_check_dir_entry(dir, NULL, de, bh,
+ bh->b_data,
+ bh->b_size, offset)) {
+ res = -1;
+ goto return_result;
+ }
+ *res_dir = de;
+ res = 1;
+ goto return_result;
+ }
- if ((char *) de + namelen <= dlimit &&
- ext4_match (namelen, name, de)) {
- /* found a match - just to be sure, do a full check */
- if (ext4_check_dir_entry(dir, NULL, de, bh, bh->b_data,
- bh->b_size, offset))
- return -1;
- *res_dir = de;
- return 1;
}
/* prevent looping on a bad block */
de_len = ext4_rec_len_from_disk(de->rec_len,
dir->i_sb->s_blocksize);
- if (de_len <= 0)
- return -1;
+ if (de_len <= 0) {
+ res = -1;
+ goto return_result;
+ }
offset += de_len;
de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
}
- return 0;
+
+ res = 0;
+return_result:
+ ext4_put_fname_crypto_ctx(&ctx);
+ ext4_fname_crypto_free_buffer((void **)&fname_crypto_str.name);
+ return res;
}
static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block,
@@ -1462,6 +1582,9 @@ static struct buffer_head * ext4_dx_find_entry(struct inode *dir, const struct q
ext4_lblk_t block;
int retval;
+#ifdef CONFIG_EXT4_FS_ENCRYPTION
+ *res_dir = NULL;
+#endif
frame = dx_probe(d_name, dir, &hinfo, frames);
if (IS_ERR(frame))
return (struct buffer_head *) frame;
@@ -1665,7 +1788,7 @@ static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
/* create map in the end of data2 block */
map = (struct dx_map_entry *) (data2 + blocksize);
- count = dx_make_map((struct ext4_dir_entry_2 *) data1,
+ count = dx_make_map(dir, (struct ext4_dir_entry_2 *) data1,
blocksize, hinfo, map);
map -= count;
dx_sort_map(map, count);
@@ -1688,7 +1811,8 @@ static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
hash2, split, count-split));
/* Fancy dance to stay within two buffers */
- de2 = dx_move_dirents(data1, data2, map + split, count - split, blocksize);
+ de2 = dx_move_dirents(data1, data2, map + split, count - split,
+ blocksize);
de = dx_pack_dirents(data1, blocksize);
de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
(char *) de,
@@ -1744,15 +1868,50 @@ int ext4_find_dest_de(struct inode *dir, struct inode *inode,
int nlen, rlen;
unsigned int offset = 0;
char *top;
+ struct ext4_fname_crypto_ctx *ctx = NULL;
+ struct ext4_str fname_crypto_str = {.name = NULL, .len = 0};
+ int res;
+
+ ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN);
+ if (IS_ERR(ctx))
+ return -1;
+
+ if (ctx != NULL) {
+ /* Calculate record length needed to store the entry */
+ res = ext4_fname_crypto_namelen_on_disk(ctx, namelen);
+ if (res < 0) {
+ ext4_put_fname_crypto_ctx(&ctx);
+ return res;
+ }
+ reclen = EXT4_DIR_REC_LEN(res);
+
+ /* Allocate buffer to hold maximum name length */
+ res = ext4_fname_crypto_alloc_buffer(ctx,
+ &fname_crypto_str.name,
+ &fname_crypto_str.len,
+ EXT4_NAME_LEN);
+ if (res < 0) {
+ ext4_put_fname_crypto_ctx(&ctx);
+ return -1;
+ }
+ }
de = (struct ext4_dir_entry_2 *)buf;
top = buf + buf_size - reclen;
while ((char *) de <= top) {
if (ext4_check_dir_entry(dir, NULL, de, bh,
- buf, buf_size, offset))
- return -EIO;
- if (ext4_match(namelen, name, de))
- return -EEXIST;
+ buf, buf_size, offset)) {
+ res = -EIO;
+ goto return_result;
+ }
+ /* Provide crypto context and crypto buffer to ext4 match */
+ res = ext4_match(ctx, &fname_crypto_str, namelen, name, de);
+ if (res < 0)
+ goto return_result;
+ if (res > 0) {
+ res = -EEXIST;
+ goto return_result;
+ }
nlen = EXT4_DIR_REC_LEN(de->name_len);
rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
if ((de->inode ? rlen - nlen : rlen) >= reclen)
@@ -1760,11 +1919,17 @@ int ext4_find_dest_de(struct inode *dir, struct inode *inode,
de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
offset += rlen;
}
- if ((char *) de > top)
- return -ENOSPC;
- *dest_de = de;
- return 0;
+ if ((char *) de > top)
+ res = -ENOSPC;
+ else {
+ *dest_de = de;
+ res = 0;
+ }
+return_result:
+ ext4_put_fname_crypto_ctx(&ctx);
+ ext4_fname_crypto_free_buffer((void **)&fname_crypto_str.name);
+ return res;
}
int ext4_insert_dentry(struct inode *dir,
--
2.3.0
--
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