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6493792d32
Symlink's external data block is one kind of metadata block, and now that almost all ext4 metadata block's page cache (e.g. directory blocks, quota blocks...) belongs to bdev backing inode except the symlink. It is essentially worked in data=journal mode like other regular file's data block because probably in order to make it simple for generic VFS code handling symlinks or some other historical reasons, but the logic of creating external data block in ext4_symlink() is complicated. and it also make things confused if user do not want to let the filesystem worked in data=journal mode. This patch convert the final exceptional case and make things clean, move the mapping of the symlink's external data block to bdev like any other metadata block does. Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Link: https://lore.kernel.org/r/20220424140936.1898920-3-yi.zhang@huawei.com
119 lines
2.8 KiB
C
119 lines
2.8 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* linux/fs/ext4/symlink.c
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*
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* Only fast symlinks left here - the rest is done by generic code. AV, 1999
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*
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* Copyright (C) 1992, 1993, 1994, 1995
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* Remy Card (card@masi.ibp.fr)
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* Laboratoire MASI - Institut Blaise Pascal
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* Universite Pierre et Marie Curie (Paris VI)
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*
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* from
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*
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* linux/fs/minix/symlink.c
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*
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* Copyright (C) 1991, 1992 Linus Torvalds
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*
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* ext4 symlink handling code
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*/
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#include <linux/fs.h>
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#include <linux/namei.h>
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#include "ext4.h"
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#include "xattr.h"
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static const char *ext4_encrypted_get_link(struct dentry *dentry,
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struct inode *inode,
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struct delayed_call *done)
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{
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struct buffer_head *bh = NULL;
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const void *caddr;
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unsigned int max_size;
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const char *paddr;
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if (!dentry)
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return ERR_PTR(-ECHILD);
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if (ext4_inode_is_fast_symlink(inode)) {
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caddr = EXT4_I(inode)->i_data;
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max_size = sizeof(EXT4_I(inode)->i_data);
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} else {
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bh = ext4_bread(NULL, inode, 0, 0);
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if (IS_ERR(bh))
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return ERR_CAST(bh);
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if (!bh) {
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EXT4_ERROR_INODE(inode, "bad symlink.");
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return ERR_PTR(-EFSCORRUPTED);
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}
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caddr = bh->b_data;
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max_size = inode->i_sb->s_blocksize;
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}
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paddr = fscrypt_get_symlink(inode, caddr, max_size, done);
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brelse(bh);
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return paddr;
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}
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static int ext4_encrypted_symlink_getattr(struct user_namespace *mnt_userns,
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const struct path *path,
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struct kstat *stat, u32 request_mask,
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unsigned int query_flags)
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{
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ext4_getattr(mnt_userns, path, stat, request_mask, query_flags);
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return fscrypt_symlink_getattr(path, stat);
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}
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static void ext4_free_link(void *bh)
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{
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brelse(bh);
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}
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static const char *ext4_get_link(struct dentry *dentry, struct inode *inode,
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struct delayed_call *callback)
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{
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struct buffer_head *bh;
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if (!dentry) {
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bh = ext4_getblk(NULL, inode, 0, EXT4_GET_BLOCKS_CACHED_NOWAIT);
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if (IS_ERR(bh))
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return ERR_CAST(bh);
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if (!bh || !ext4_buffer_uptodate(bh))
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return ERR_PTR(-ECHILD);
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} else {
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bh = ext4_bread(NULL, inode, 0, 0);
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if (IS_ERR(bh))
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return ERR_CAST(bh);
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if (!bh) {
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EXT4_ERROR_INODE(inode, "bad symlink.");
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return ERR_PTR(-EFSCORRUPTED);
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}
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}
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set_delayed_call(callback, ext4_free_link, bh);
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nd_terminate_link(bh->b_data, inode->i_size,
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inode->i_sb->s_blocksize - 1);
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return bh->b_data;
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}
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const struct inode_operations ext4_encrypted_symlink_inode_operations = {
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.get_link = ext4_encrypted_get_link,
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.setattr = ext4_setattr,
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.getattr = ext4_encrypted_symlink_getattr,
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.listxattr = ext4_listxattr,
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};
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const struct inode_operations ext4_symlink_inode_operations = {
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.get_link = ext4_get_link,
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.setattr = ext4_setattr,
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.getattr = ext4_getattr,
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.listxattr = ext4_listxattr,
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};
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const struct inode_operations ext4_fast_symlink_inode_operations = {
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.get_link = simple_get_link,
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.setattr = ext4_setattr,
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.getattr = ext4_getattr,
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.listxattr = ext4_listxattr,
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};
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