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// SPDX-License-Identifier: GPL-2.0
/*
* linux/fs/ext4/symlink.c
*
* Only fast symlinks left here - the rest is done by generic code. AV, 1999
*
* Copyright (C) 1992, 1993, 1994, 1995
* Remy Card (card@masi.ibp.fr)
* Laboratoire MASI - Institut Blaise Pascal
* Universite Pierre et Marie Curie (Paris VI)
*
* from
*
* linux/fs/minix/symlink.c
*
* Copyright (C) 1991, 1992 Linus Torvalds
*
* ext4 symlink handling code
*/
#include <linux/fs.h>
#include <linux/namei.h>
#include "ext4.h"
#include "xattr.h"
static const char *ext4_encrypted_get_link(struct dentry *dentry,
struct inode *inode,
struct delayed_call *done)
{
struct buffer_head *bh = NULL;
const void *caddr;
unsigned int max_size;
const char *paddr;
if (!dentry)
return ERR_PTR(-ECHILD);
if (ext4_inode_is_fast_symlink(inode)) {
caddr = EXT4_I(inode)->i_data;
max_size = sizeof(EXT4_I(inode)->i_data);
} else {
bh = ext4_bread(NULL, inode, 0, 0);
if (IS_ERR(bh))
return ERR_CAST(bh);
if (!bh) {
EXT4_ERROR_INODE(inode, "bad symlink.");
return ERR_PTR(-EFSCORRUPTED);
}
caddr = bh->b_data;
max_size = inode->i_sb->s_blocksize;
}
paddr = fscrypt_get_symlink(inode, caddr, max_size, done);
brelse(bh);
return paddr;
}
static int ext4_encrypted_symlink_getattr(struct mnt_idmap *idmap,
const struct path *path,
struct kstat *stat, u32 request_mask,
unsigned int query_flags)
{
ext4_getattr(idmap, path, stat, request_mask, query_flags);
return fscrypt_symlink_getattr(path, stat);
}
static void ext4_free_link(void *bh)
{
brelse(bh);
}
static const char *ext4_get_link(struct dentry *dentry, struct inode *inode,
struct delayed_call *callback)
{
struct buffer_head *bh;
char *inline_link;
/*
* Create a new inlined symlink is not supported, just provide a
* method to read the leftovers.
*/
if (ext4_has_inline_data(inode)) {
if (!dentry)
return ERR_PTR(-ECHILD);
inline_link = ext4_read_inline_link(inode);
if (!IS_ERR(inline_link))
set_delayed_call(callback, kfree_link, inline_link);
return inline_link;
}
if (!dentry) {
bh = ext4_getblk(NULL, inode, 0, EXT4_GET_BLOCKS_CACHED_NOWAIT);
if (IS_ERR(bh) || !bh)
return ERR_PTR(-ECHILD);
if (!ext4_buffer_uptodate(bh)) {
brelse(bh);
return ERR_PTR(-ECHILD);
}
} else {
bh = ext4_bread(NULL, inode, 0, 0);
if (IS_ERR(bh))
return ERR_CAST(bh);
if (!bh) {
EXT4_ERROR_INODE(inode, "bad symlink.");
return ERR_PTR(-EFSCORRUPTED);
}
}
set_delayed_call(callback, ext4_free_link, bh);
nd_terminate_link(bh->b_data, inode->i_size,
inode->i_sb->s_blocksize - 1);
return bh->b_data;
}
const struct inode_operations ext4_encrypted_symlink_inode_operations = {
.get_link = ext4_encrypted_get_link,
.setattr = ext4_setattr,
.getattr = ext4_encrypted_symlink_getattr,
.listxattr = ext4_listxattr,
};
const struct inode_operations ext4_symlink_inode_operations = {
.get_link = ext4_get_link,
.setattr = ext4_setattr,
.getattr = ext4_getattr,
.listxattr = ext4_listxattr,
};
const struct inode_operations ext4_fast_symlink_inode_operations = {
.get_link = simple_get_link,
.setattr = ext4_setattr,
.getattr = ext4_getattr,
.listxattr = ext4_listxattr,
};
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