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Message-ID: <20211230120554.000008bc.zbestahu@gmail.com>
Date: Thu, 30 Dec 2021 12:05:54 +0800
From: Yue Hu <zbestahu@...il.com>
To: Gao Xiang <hsiangkao@...ux.alibaba.com>
Cc: linux-erofs@...ts.ozlabs.org, Chao Yu <chao@...nel.org>,
Liu Bo <bo.liu@...ux.alibaba.com>,
LKML <linux-kernel@...r.kernel.org>, geshifei@...lpad.com,
zhangwen@...lpad.com, shaojunjun@...lpad.com, huyue@...lpad.com
Subject: Re: [PATCH 2/5] erofs: use meta buffers for inode operations
On Wed, 29 Dec 2021 12:14:02 +0800
Gao Xiang <hsiangkao@...ux.alibaba.com> wrote:
> Get rid of old erofs_get_meta_page() within inode operations by
> using on-stack meta buffers in order to prepare subpage and folio
> features.
>
> Signed-off-by: Gao Xiang <hsiangkao@...ux.alibaba.com>
> ---
> fs/erofs/inode.c | 68 +++++++++++++++++++++------------------------
> fs/erofs/internal.h | 3 ++
> 2 files changed, 35 insertions(+), 36 deletions(-)
>
> diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c
> index 2345f1de438e..ff62f84f47d3 100644
> --- a/fs/erofs/inode.c
> +++ b/fs/erofs/inode.c
> @@ -13,8 +13,8 @@
> * the inode payload page if it's an extended inode) in order to fill
> * inline data if possible.
> */
> -static struct page *erofs_read_inode(struct inode *inode,
> - unsigned int *ofs)
> +static void *erofs_read_inode(struct erofs_buf *buf,
> + struct inode *inode, unsigned int *ofs)
> {
> struct super_block *sb = inode->i_sb;
> struct erofs_sb_info *sbi = EROFS_SB(sb);
> @@ -22,7 +22,7 @@ static struct page *erofs_read_inode(struct inode *inode,
> const erofs_off_t inode_loc = iloc(sbi, vi->nid);
>
> erofs_blk_t blkaddr, nblks = 0;
> - struct page *page;
> + void *kaddr;
> struct erofs_inode_compact *dic;
> struct erofs_inode_extended *die, *copied = NULL;
> unsigned int ifmt;
> @@ -34,14 +34,14 @@ static struct page *erofs_read_inode(struct inode *inode,
> erofs_dbg("%s, reading inode nid %llu at %u of blkaddr %u",
> __func__, vi->nid, *ofs, blkaddr);
>
> - page = erofs_get_meta_page(sb, blkaddr);
> - if (IS_ERR(page)) {
> + kaddr = erofs_read_metabuf(buf, sb, blkaddr, EROFS_KMAP);
> + if (IS_ERR(kaddr)) {
> erofs_err(sb, "failed to get inode (nid: %llu) page, err %ld",
> - vi->nid, PTR_ERR(page));
> - return page;
> + vi->nid, PTR_ERR(kaddr));
> + return kaddr;
> }
>
> - dic = page_address(page) + *ofs;
> + dic = kaddr + *ofs;
> ifmt = le16_to_cpu(dic->i_format);
>
> if (ifmt & ~EROFS_I_ALL) {
> @@ -62,12 +62,12 @@ static struct page *erofs_read_inode(struct inode *inode,
> switch (erofs_inode_version(ifmt)) {
> case EROFS_INODE_LAYOUT_EXTENDED:
> vi->inode_isize = sizeof(struct erofs_inode_extended);
> - /* check if the inode acrosses page boundary */
> - if (*ofs + vi->inode_isize <= PAGE_SIZE) {
> + /* check if the extended inode acrosses block boundary */
> + if (*ofs + vi->inode_isize <= EROFS_BLKSIZ) {
> *ofs += vi->inode_isize;
> die = (struct erofs_inode_extended *)dic;
> } else {
> - const unsigned int gotten = PAGE_SIZE - *ofs;
> + const unsigned int gotten = EROFS_BLKSIZ - *ofs;
>
> copied = kmalloc(vi->inode_isize, GFP_NOFS);
> if (!copied) {
> @@ -75,18 +75,16 @@ static struct page *erofs_read_inode(struct inode *inode,
> goto err_out;
> }
> memcpy(copied, dic, gotten);
> - unlock_page(page);
> - put_page(page);
> -
> - page = erofs_get_meta_page(sb, blkaddr + 1);
> - if (IS_ERR(page)) {
> - erofs_err(sb, "failed to get inode payload page (nid: %llu), err %ld",
> - vi->nid, PTR_ERR(page));
> + kaddr = erofs_read_metabuf(buf, sb, blkaddr + 1,
> + EROFS_KMAP);
> + if (IS_ERR(kaddr)) {
> + erofs_err(sb, "failed to get inode payload block (nid: %llu), err %ld",
> + vi->nid, PTR_ERR(kaddr));
> kfree(copied);
> - return page;
> + return kaddr;
> }
> *ofs = vi->inode_isize - gotten;
> - memcpy((u8 *)copied + gotten, page_address(page), *ofs);
> + memcpy((u8 *)copied + gotten, kaddr, *ofs);
> die = copied;
> }
> vi->xattr_isize = erofs_xattr_ibody_size(die->i_xattr_icount);
> @@ -200,7 +198,7 @@ static struct page *erofs_read_inode(struct inode *inode,
> inode->i_blocks = roundup(inode->i_size, EROFS_BLKSIZ) >> 9;
> else
> inode->i_blocks = nblks << LOG_SECTORS_PER_BLOCK;
> - return page;
> + return kaddr;
>
> bogusimode:
> erofs_err(inode->i_sb, "bogus i_mode (%o) @ nid %llu",
> @@ -209,12 +207,11 @@ static struct page *erofs_read_inode(struct inode *inode,
> err_out:
> DBG_BUGON(1);
> kfree(copied);
> - unlock_page(page);
> - put_page(page);
> + erofs_put_metabuf(buf);
> return ERR_PTR(err);
> }
>
> -static int erofs_fill_symlink(struct inode *inode, void *data,
> +static int erofs_fill_symlink(struct inode *inode, void *kaddr,
> unsigned int m_pofs)
> {
> struct erofs_inode *vi = EROFS_I(inode);
> @@ -222,7 +219,7 @@ static int erofs_fill_symlink(struct inode *inode, void *data,
>
> /* if it cannot be handled with fast symlink scheme */
> if (vi->datalayout != EROFS_INODE_FLAT_INLINE ||
> - inode->i_size >= PAGE_SIZE) {
> + inode->i_size >= EROFS_BLKSIZ) {
> inode->i_op = &erofs_symlink_iops;
> return 0;
> }
> @@ -232,8 +229,8 @@ static int erofs_fill_symlink(struct inode *inode, void *data,
> return -ENOMEM;
>
> m_pofs += vi->xattr_isize;
> - /* inline symlink data shouldn't cross page boundary as well */
> - if (m_pofs + inode->i_size > PAGE_SIZE) {
> + /* inline symlink data shouldn't cross block boundary */
> + if (m_pofs + inode->i_size > EROFS_BLKSIZ) {
> kfree(lnk);
> erofs_err(inode->i_sb,
> "inline data cross block boundary @ nid %llu",
> @@ -241,8 +238,7 @@ static int erofs_fill_symlink(struct inode *inode, void *data,
> DBG_BUGON(1);
> return -EFSCORRUPTED;
> }
> -
> - memcpy(lnk, data + m_pofs, inode->i_size);
> + memcpy(lnk, kaddr + m_pofs, inode->i_size);
> lnk[inode->i_size] = '\0';
>
> inode->i_link = lnk;
> @@ -253,16 +249,17 @@ static int erofs_fill_symlink(struct inode *inode, void *data,
> static int erofs_fill_inode(struct inode *inode, int isdir)
> {
> struct erofs_inode *vi = EROFS_I(inode);
> - struct page *page;
> + struct erofs_buf buf = __EROFS_BUF_INITIALIZER;
> + void *kaddr;
> unsigned int ofs;
> int err = 0;
>
> trace_erofs_fill_inode(inode, isdir);
>
> /* read inode base data from disk */
> - page = erofs_read_inode(inode, &ofs);
> - if (IS_ERR(page))
> - return PTR_ERR(page);
> + kaddr = erofs_read_inode(&buf, inode, &ofs);
> + if (IS_ERR(kaddr))
> + return PTR_ERR(kaddr);
>
> /* setup the new inode */
> switch (inode->i_mode & S_IFMT) {
> @@ -278,7 +275,7 @@ static int erofs_fill_inode(struct inode *inode, int isdir)
> inode->i_fop = &erofs_dir_fops;
> break;
> case S_IFLNK:
> - err = erofs_fill_symlink(inode, page_address(page), ofs);
> + err = erofs_fill_symlink(inode, kaddr, ofs);
> if (err)
> goto out_unlock;
> inode_nohighmem(inode);
> @@ -302,8 +299,7 @@ static int erofs_fill_inode(struct inode *inode, int isdir)
> inode->i_mapping->a_ops = &erofs_raw_access_aops;
>
> out_unlock:
> - unlock_page(page);
> - put_page(page);
> + erofs_put_metabuf(&buf);
> return err;
> }
>
> diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
> index 7053f1c4171d..f1e4eb3025f6 100644
> --- a/fs/erofs/internal.h
> +++ b/fs/erofs/internal.h
> @@ -475,6 +475,9 @@ struct erofs_map_dev {
> /* data.c */
> extern const struct file_operations erofs_file_fops;
> struct page *erofs_get_meta_page(struct super_block *sb, erofs_blk_t blkaddr);
> +void erofs_put_metabuf(struct erofs_buf *buf);
> +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);
> int erofs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
> u64 start, u64 len);
Reviewed-by: Yue Hu <huyue2@...ong.com>
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