ext4: switch to fscrypt ->symlink() helper functions

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

1 files changed, 15 insertions, 43 deletions

diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index e750d68fbcb5..727675794a45 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -3056,39 +3056,19 @@ static int ext4_symlink(struct inode *dir,
         struct inode *inode;
         int err, len = strlen(symname);
         int credits;
-        bool encryption_required;
         struct fscrypt_str disk_link;
-        struct fscrypt_symlink_data *sd = NULL;
 
         if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
                 return -EIO;
 
-        disk_link.len = len + 1;
-        disk_link.name = (char *) symname;
-
-        encryption_required = (ext4_encrypted_inode(dir) ||
-                               DUMMY_ENCRYPTION_ENABLED(EXT4_SB(dir->i_sb)));
-        if (encryption_required) {
-                err = fscrypt_get_encryption_info(dir);
-                if (err)
-                        return err;
-                if (!fscrypt_has_encryption_key(dir))
-                        return -ENOKEY;
-                disk_link.len = (fscrypt_fname_encrypted_size(dir, len) +
-                                 sizeof(struct fscrypt_symlink_data));
-                sd = kzalloc(disk_link.len, GFP_KERNEL);
-                if (!sd)
-                        return -ENOMEM;
-        }
-
-        if (disk_link.len > dir->i_sb->s_blocksize) {
-                err = -ENAMETOOLONG;
-                goto err_free_sd;
-        }
+        err = fscrypt_prepare_symlink(dir, symname, len, dir->i_sb->s_blocksize,
+                                      &disk_link);
+        if (err)
+                return err;
 
         err = dquot_initialize(dir);
         if (err)
-                goto err_free_sd;
+                return err;
 
         if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
                 /*
@@ -3117,27 +3097,18 @@ static int ext4_symlink(struct inode *dir,
         if (IS_ERR(inode)) {
                 if (handle)
                         ext4_journal_stop(handle);
-                err = PTR_ERR(inode);
-                goto err_free_sd;
+                return PTR_ERR(inode);
         }
 
-        if (encryption_required) {
-                struct qstr istr;
-                struct fscrypt_str ostr =
-                        FSTR_INIT(sd->encrypted_path, disk_link.len);
-
-                istr.name = (const unsigned char *) symname;
-                istr.len = len;
-                err = fscrypt_fname_usr_to_disk(inode, &istr, &ostr);
+        if (IS_ENCRYPTED(inode)) {
+                err = fscrypt_encrypt_symlink(inode, symname, len, &disk_link);
                 if (err)
                         goto err_drop_inode;
-                sd->len = cpu_to_le16(ostr.len);
-                disk_link.name = (char *) sd;
                 inode->i_op = &ext4_encrypted_symlink_inode_operations;
         }
 
         if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
-                if (!encryption_required)
+                if (!IS_ENCRYPTED(inode))
                         inode->i_op = &ext4_symlink_inode_operations;
                 inode_nohighmem(inode);
                 ext4_set_aops(inode);
@@ -3179,7 +3150,7 @@ static int ext4_symlink(struct inode *dir,
         } else {
                 /* clear the extent format for fast symlink */
                 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
-                if (!encryption_required) {
+                if (!IS_ENCRYPTED(inode)) {
                         inode->i_op = &ext4_fast_symlink_inode_operations;
                         inode->i_link = (char *)&EXT4_I(inode)->i_data;
                 }
@@ -3194,16 +3165,17 @@ static int ext4_symlink(struct inode *dir,
 
         if (handle)
                 ext4_journal_stop(handle);
-        kfree(sd);
-        return err;
+        goto out_free_encrypted_link;
+
 err_drop_inode:
         if (handle)
                 ext4_journal_stop(handle);
         clear_nlink(inode);
         unlock_new_inode(inode);
         iput(inode);
-err_free_sd:
-        kfree(sd);
+out_free_encrypted_link:
+        if (disk_link.name != (unsigned char *)symname)
+                kfree(disk_link.name);
         return err;
 }