erofs: use meta buffers for reading directories

Previously, directory inodes are directly handled with page cache
interfaces.

In order to support sub-page directory blocks and folios, let's
convert them into the latest metabuf infrastructure as well and
this patch addresses the readdir case first.

Link: https://lore.kernel.org/r/20220316012246.95131-1-hsiangkao@linux.alibaba.com
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
This commit is contained in:
Gao Xiang 2022-03-16 09:22:45 +08:00
parent a942da24ab
commit fe5de5859d
3 changed files with 17 additions and 18 deletions

View File

@ -28,10 +28,10 @@ void erofs_put_metabuf(struct erofs_buf *buf)
buf->page = NULL;
}
void *erofs_read_metabuf(struct erofs_buf *buf, struct super_block *sb,
erofs_blk_t blkaddr, enum erofs_kmap_type type)
void *erofs_bread(struct erofs_buf *buf, struct inode *inode,
erofs_blk_t blkaddr, enum erofs_kmap_type type)
{
struct address_space *const mapping = sb->s_bdev->bd_inode->i_mapping;
struct address_space *const mapping = inode->i_mapping;
erofs_off_t offset = blknr_to_addr(blkaddr);
pgoff_t index = offset >> PAGE_SHIFT;
struct page *page = buf->page;
@ -60,6 +60,12 @@ void *erofs_read_metabuf(struct erofs_buf *buf, struct super_block *sb,
return buf->base + (offset & ~PAGE_MASK);
}
void *erofs_read_metabuf(struct erofs_buf *buf, struct super_block *sb,
erofs_blk_t blkaddr, enum erofs_kmap_type type)
{
return erofs_bread(buf, sb->s_bdev->bd_inode, blkaddr, type);
}
static int erofs_map_blocks_flatmode(struct inode *inode,
struct erofs_map_blocks *map,
int flags)

View File

@ -2,6 +2,7 @@
/*
* Copyright (C) 2017-2018 HUAWEI, Inc.
* https://www.huawei.com/
* Copyright (C) 2022, Alibaba Cloud
*/
#include "internal.h"
@ -67,7 +68,7 @@ static int erofs_fill_dentries(struct inode *dir, struct dir_context *ctx,
static int erofs_readdir(struct file *f, struct dir_context *ctx)
{
struct inode *dir = file_inode(f);
struct address_space *mapping = dir->i_mapping;
struct erofs_buf buf = __EROFS_BUF_INITIALIZER;
const size_t dirsize = i_size_read(dir);
unsigned int i = ctx->pos / EROFS_BLKSIZ;
unsigned int ofs = ctx->pos % EROFS_BLKSIZ;
@ -75,26 +76,19 @@ static int erofs_readdir(struct file *f, struct dir_context *ctx)
bool initial = true;
while (ctx->pos < dirsize) {
struct page *dentry_page;
struct erofs_dirent *de;
unsigned int nameoff, maxsize;
dentry_page = read_mapping_page(mapping, i, NULL);
if (dentry_page == ERR_PTR(-ENOMEM)) {
err = -ENOMEM;
break;
} else if (IS_ERR(dentry_page)) {
de = erofs_bread(&buf, dir, i, EROFS_KMAP);
if (IS_ERR(de)) {
erofs_err(dir->i_sb,
"fail to readdir of logical block %u of nid %llu",
i, EROFS_I(dir)->nid);
err = -EFSCORRUPTED;
err = PTR_ERR(de);
break;
}
de = (struct erofs_dirent *)kmap(dentry_page);
nameoff = le16_to_cpu(de->nameoff);
if (nameoff < sizeof(struct erofs_dirent) ||
nameoff >= PAGE_SIZE) {
erofs_err(dir->i_sb,
@ -119,10 +113,6 @@ static int erofs_readdir(struct file *f, struct dir_context *ctx)
err = erofs_fill_dentries(dir, ctx, de, &ofs,
nameoff, maxsize);
skip_this:
kunmap(dentry_page);
put_page(dentry_page);
ctx->pos = blknr_to_addr(i) + ofs;
if (err)
@ -130,6 +120,7 @@ skip_this:
++i;
ofs = 0;
}
erofs_put_metabuf(&buf);
return err < 0 ? err : 0;
}

View File

@ -479,6 +479,8 @@ struct erofs_map_dev {
extern const struct file_operations erofs_file_fops;
void erofs_unmap_metabuf(struct erofs_buf *buf);
void erofs_put_metabuf(struct erofs_buf *buf);
void *erofs_bread(struct erofs_buf *buf, struct inode *inode,
erofs_blk_t blkaddr, enum erofs_kmap_type type);
void *erofs_read_metabuf(struct erofs_buf *buf, struct super_block *sb,
erofs_blk_t blkaddr, enum erofs_kmap_type type);
int erofs_map_dev(struct super_block *sb, struct erofs_map_dev *dev);