Re: [PATCH 4/4] minixfs: switch to kmap_local_page()

[Fabio M. De Francesco]

On Wednesday, 13 December 2023 01:08:49 CET Al Viro wrote:
> Again, a counterpart of Fabio's fs/sysv patch
> 
> Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
> ---
>  fs/minix/dir.c   | 27 +++++++++++++--------------
>  fs/minix/minix.h |  5 -----
>  fs/minix/namei.c |  6 +++---
>  3 files changed, 16 insertions(+), 22 deletions(-)

Reviewed-by: Fabio M. De Francesco <fabio.maria.de.francesco@xxxxxxxxxxxxxxx>

> diff --git a/fs/minix/dir.c b/fs/minix/dir.c
> index ccb6c47fd7fe..a224cf222570 100644
> --- a/fs/minix/dir.c
> +++ b/fs/minix/dir.c
> @@ -70,9 +70,8 @@ static void *dir_get_page(struct inode *dir, unsigned long
> n, struct page **p) struct page *page = read_mapping_page(mapping, n,
> NULL);
>  	if (IS_ERR(page))
>  		return ERR_CAST(page);
> -	kmap(page);
>  	*p = page;
> -	return page_address(page);
> +	return kmap_local_page(page);
>  }
> 
>  static inline void *minix_next_entry(void *de, struct minix_sb_info *sbi)
> @@ -123,13 +122,13 @@ static int minix_readdir(struct file *file, struct
> dir_context *ctx) unsigned l = strnlen(name, sbi->s_namelen);
>  				if (!dir_emit(ctx, name, l,
>  					      inumber, DT_UNKNOWN)) {
> -					dir_put_page(page);
> +					unmap_and_put_page(page, p);
>  					return 0;
>  				}
>  			}
>  			ctx->pos += chunk_size;
>  		}
> -		dir_put_page(page);
> +		unmap_and_put_page(page, kaddr);
>  	}
>  	return 0;
>  }
> @@ -189,7 +188,7 @@ minix_dirent *minix_find_entry(struct dentry *dentry,
> struct page **res_page) if (namecompare(namelen, sbi->s_namelen, name,
> namx))
>  				goto found;
>  		}
> -		dir_put_page(page);
> +		unmap_and_put_page(page, kaddr);
>  	}
>  	return NULL;
> 
> @@ -255,7 +254,7 @@ int minix_add_link(struct dentry *dentry, struct inode
> *inode) goto out_unlock;
>  		}
>  		unlock_page(page);
> -		dir_put_page(page);
> +		unmap_and_put_page(page, kaddr);
>  	}
>  	BUG();
>  	return -EINVAL;
> @@ -278,7 +277,7 @@ int minix_add_link(struct dentry *dentry, struct inode
> *inode) mark_inode_dirty(dir);
>  	err = minix_handle_dirsync(dir);
>  out_put:
> -	dir_put_page(page);
> +	unmap_and_put_page(page, kaddr);
>  	return err;
>  out_unlock:
>  	unlock_page(page);
> @@ -324,7 +323,7 @@ int minix_make_empty(struct inode *inode, struct inode
> *dir) goto fail;
>  	}
> 
> -	kaddr = kmap_atomic(page);
> +	kaddr = kmap_local_page(page);
>  	memset(kaddr, 0, PAGE_SIZE);
> 
>  	if (sbi->s_version == MINIX_V3) {
> @@ -344,7 +343,7 @@ int minix_make_empty(struct inode *inode, struct inode
> *dir) de->inode = dir->i_ino;
>  		strcpy(de->name, "..");
>  	}
> -	kunmap_atomic(kaddr);
> +	kunmap_local(kaddr);
> 
>  	dir_commit_chunk(page, 0, 2 * sbi->s_dirsize);
>  	err = minix_handle_dirsync(inode);
> @@ -361,11 +360,11 @@ int minix_empty_dir(struct inode * inode)
>  	struct page *page = NULL;
>  	unsigned long i, npages = dir_pages(inode);
>  	struct minix_sb_info *sbi = minix_sb(inode->i_sb);
> -	char *name;
> +	char *name, *kaddr;
>  	__u32 inumber;
> 
>  	for (i = 0; i < npages; i++) {
> -		char *p, *kaddr, *limit;
> +		char *p, *limit;
> 
>  		kaddr = dir_get_page(inode, i, &page);
>  		if (IS_ERR(kaddr))
> @@ -396,12 +395,12 @@ int minix_empty_dir(struct inode * inode)
>  					goto not_empty;
>  			}
>  		}
> -		dir_put_page(page);
> +		unmap_and_put_page(page, kaddr);
>  	}
>  	return 1;
> 
>  not_empty:
> -	dir_put_page(page);
> +	unmap_and_put_page(page, kaddr);
>  	return 0;
>  }
> 
> @@ -455,7 +454,7 @@ ino_t minix_inode_by_name(struct dentry *dentry)
>  			res = ((minix3_dirent *) de)->inode;
>  		else
>  			res = de->inode;
> -		dir_put_page(page);
> +		unmap_and_put_page(page, de);
>  	}
>  	return res;
>  }
> diff --git a/fs/minix/minix.h b/fs/minix/minix.h
> index cb42b6cf7909..d493507c064f 100644
> --- a/fs/minix/minix.h
> +++ b/fs/minix/minix.h
> @@ -64,11 +64,6 @@ extern int V2_minix_get_block(struct inode *, long,
> struct buffer_head *, int); extern unsigned V1_minix_blocks(loff_t, struct
> super_block *);
>  extern unsigned V2_minix_blocks(loff_t, struct super_block *);
> 
> -static inline void dir_put_page(struct page *page)
> -{
> -	kunmap(page);
> -	put_page(page);
> -}
>  extern struct minix_dir_entry *minix_find_entry(struct dentry*, struct
> page**); extern int minix_add_link(struct dentry*, struct inode*);
>  extern int minix_delete_entry(struct minix_dir_entry*, struct page*);
> diff --git a/fs/minix/namei.c b/fs/minix/namei.c
> index 20923a15e30a..d6031acc34f0 100644
> --- a/fs/minix/namei.c
> +++ b/fs/minix/namei.c
> @@ -149,7 +149,7 @@ static int minix_unlink(struct inode * dir, struct
> dentry *dentry) if (!de)
>  		return -ENOENT;
>  	err = minix_delete_entry(de, page);
> -	dir_put_page(page);
> +	unmap_and_put_page(page, de);
> 
>  	if (err)
>  		return err;
> @@ -242,9 +242,9 @@ static int minix_rename(struct mnt_idmap *idmap,
>  	}
>  out_dir:
>  	if (dir_de)
> -		dir_put_page(dir_page);
> +		unmap_and_put_page(dir_page, dir_de);
>  out_old:
> -	dir_put_page(old_page);
> +	unmap_and_put_page(old_page, old_de);
>  out:
>  	return err;
>  }