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1// SPDX-License-Identifier: GPL-2.02/*3 * linux/fs/ext4/symlink.c4 *5 * Only fast symlinks left here - the rest is done by generic code. AV, 19996 *7 * Copyright (C) 1992, 1993, 1994, 19958 * Remy Card (card@masi.ibp.fr)9 * Laboratoire MASI - Institut Blaise Pascal10 * Universite Pierre et Marie Curie (Paris VI)11 *12 * from13 *14 * linux/fs/minix/symlink.c15 *16 * Copyright (C) 1991, 1992 Linus Torvalds17 *18 * ext4 symlink handling code19 */20 21#include <linux/fs.h>22#include <linux/namei.h>23#include "ext4.h"24#include "xattr.h"25 26static const char *ext4_encrypted_get_link(struct dentry *dentry,27 struct inode *inode,28 struct delayed_call *done)29{30 struct buffer_head *bh = NULL;31 const void *caddr;32 unsigned int max_size;33 const char *paddr;34 35 if (!dentry)36 return ERR_PTR(-ECHILD);37 38 if (ext4_inode_is_fast_symlink(inode)) {39 caddr = EXT4_I(inode)->i_data;40 max_size = sizeof(EXT4_I(inode)->i_data);41 } else {42 bh = ext4_bread(NULL, inode, 0, 0);43 if (IS_ERR(bh))44 return ERR_CAST(bh);45 if (!bh) {46 EXT4_ERROR_INODE(inode, "bad symlink.");47 return ERR_PTR(-EFSCORRUPTED);48 }49 caddr = bh->b_data;50 max_size = inode->i_sb->s_blocksize;51 }52 53 paddr = fscrypt_get_symlink(inode, caddr, max_size, done);54 brelse(bh);55 return paddr;56}57 58static int ext4_encrypted_symlink_getattr(struct mnt_idmap *idmap,59 const struct path *path,60 struct kstat *stat, u32 request_mask,61 unsigned int query_flags)62{63 ext4_getattr(idmap, path, stat, request_mask, query_flags);64 65 return fscrypt_symlink_getattr(path, stat);66}67 68static void ext4_free_link(void *bh)69{70 brelse(bh);71}72 73static const char *ext4_get_link(struct dentry *dentry, struct inode *inode,74 struct delayed_call *callback)75{76 struct buffer_head *bh;77 char *inline_link;78 79 /*80 * Create a new inlined symlink is not supported, just provide a81 * method to read the leftovers.82 */83 if (ext4_has_inline_data(inode)) {84 if (!dentry)85 return ERR_PTR(-ECHILD);86 87 inline_link = ext4_read_inline_link(inode);88 if (!IS_ERR(inline_link))89 set_delayed_call(callback, kfree_link, inline_link);90 return inline_link;91 }92 93 if (!dentry) {94 bh = ext4_getblk(NULL, inode, 0, EXT4_GET_BLOCKS_CACHED_NOWAIT);95 if (IS_ERR(bh) || !bh)96 return ERR_PTR(-ECHILD);97 if (!ext4_buffer_uptodate(bh)) {98 brelse(bh);99 return ERR_PTR(-ECHILD);100 }101 } else {102 bh = ext4_bread(NULL, inode, 0, 0);103 if (IS_ERR(bh))104 return ERR_CAST(bh);105 if (!bh) {106 EXT4_ERROR_INODE(inode, "bad symlink.");107 return ERR_PTR(-EFSCORRUPTED);108 }109 }110 111 set_delayed_call(callback, ext4_free_link, bh);112 nd_terminate_link(bh->b_data, inode->i_size,113 inode->i_sb->s_blocksize - 1);114 return bh->b_data;115}116 117const struct inode_operations ext4_encrypted_symlink_inode_operations = {118 .get_link = ext4_encrypted_get_link,119 .setattr = ext4_setattr,120 .getattr = ext4_encrypted_symlink_getattr,121 .listxattr = ext4_listxattr,122};123 124const struct inode_operations ext4_symlink_inode_operations = {125 .get_link = ext4_get_link,126 .setattr = ext4_setattr,127 .getattr = ext4_getattr,128 .listxattr = ext4_listxattr,129};130 131const struct inode_operations ext4_fast_symlink_inode_operations = {132 .get_link = simple_get_link,133 .setattr = ext4_setattr,134 .getattr = ext4_getattr,135 .listxattr = ext4_listxattr,136};137