Commit 09c54379 authored by Gao Xiang's avatar Gao Xiang
Browse files

erofs: use meta buffers for zmap operations 

Get rid of old erofs_get_meta_page() within zmap operations by
using on-stack meta buffers in order to prepare subpage and folio
features.

Finally, erofs_get_meta_page() is useless. Get rid of it!

Link: https://lore.kernel.org/r/20220102040017.51352-6-hsiangkao@linux.alibaba.com


Reviewed-by: default avatarYue Hu <huyue2@yulong.com>
Reviewed-by: default avatarLiu Bo <bo.liu@linux.alibaba.com>
Reviewed-by: default avatarChao Yu <chao@kernel.org>
Signed-off-by: default avatarGao Xiang <hsiangkao@linux.alibaba.com>
parent bb88e8da

fs/erofs/data.c

+0 −13
Original line number Diff line number Diff line
@@ -9,19 +9,6 @@ 
#include <linux/dax.h>

#include <trace/events/erofs.h>



struct page *erofs_get_meta_page(struct super_block *sb, erofs_blk_t blkaddr)

{

	struct address_space *const mapping = sb->s_bdev->bd_inode->i_mapping;

	struct page *page;



	page = read_cache_page_gfp(mapping, blkaddr,

				   mapping_gfp_constraint(mapping, ~__GFP_FS));

	/* should already be PageUptodate */

	if (!IS_ERR(page))

		lock_page(page);

	return page;

}



void erofs_unmap_metabuf(struct erofs_buf *buf)

{

	if (buf->kmap_type == EROFS_KMAP)

fs/erofs/internal.h

+3 −3
Original line number Diff line number Diff line
@@ -419,14 +419,14 @@ enum { 
#define EROFS_MAP_FULL_MAPPED	(1 << BH_FullMapped)



struct erofs_map_blocks {

	struct erofs_buf buf;



	erofs_off_t m_pa, m_la;

	u64 m_plen, m_llen;



	unsigned short m_deviceid;

	char m_algorithmformat;

	unsigned int m_flags;



	struct page *mpage;

};



/* Flags used by erofs_map_blocks_flatmode() */
@@ -474,7 +474,7 @@ 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_unmap_metabuf(struct erofs_buf *buf);

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);

fs/erofs/zdata.c

+9 −14
Original line number Diff line number Diff line
@@ -698,20 +698,18 @@ static int z_erofs_do_read_page(struct z_erofs_decompress_frontend *fe, 
		goto err_out;



	if (z_erofs_is_inline_pcluster(clt->pcl)) {

		struct page *mpage;

		void *mp;



		mpage = erofs_get_meta_page(inode->i_sb,

					    erofs_blknr(map->m_pa));

		if (IS_ERR(mpage)) {

			err = PTR_ERR(mpage);

		mp = erofs_read_metabuf(&fe->map.buf, inode->i_sb,

					erofs_blknr(map->m_pa), EROFS_NO_KMAP);

		if (IS_ERR(mp)) {

			err = PTR_ERR(mp);

			erofs_err(inode->i_sb,

				  "failed to get inline page, err %d", err);

			goto err_out;

		}

		/* TODO: new subpage feature will get rid of it */

		unlock_page(mpage);



		WRITE_ONCE(clt->pcl->compressed_pages[0], mpage);

		get_page(fe->map.buf.page);

		WRITE_ONCE(clt->pcl->compressed_pages[0], fe->map.buf.page);

		clt->mode = COLLECT_PRIMARY_FOLLOWED_NOINPLACE;

	} else {

		/* preload all compressed pages (can change mode if needed) */
@@ -1529,9 +1527,7 @@ static int z_erofs_readpage(struct file *file, struct page *page) 
	if (err)

		erofs_err(inode->i_sb, "failed to read, err [%d]", err);



	if (f.map.mpage)

		put_page(f.map.mpage);



	erofs_put_metabuf(&f.map.buf);

	erofs_release_pages(&pagepool);

	return err;

}
@@ -1576,8 +1572,7 @@ static void z_erofs_readahead(struct readahead_control *rac) 


	z_erofs_runqueue(inode->i_sb, &f, &pagepool,

			 z_erofs_get_sync_decompress_policy(sbi, nr_pages));

	if (f.map.mpage)

		put_page(f.map.mpage);

	erofs_put_metabuf(&f.map.buf);

	erofs_release_pages(&pagepool);

}

fs/erofs/zmap.c

+16 −40
Original line number Diff line number Diff line
@@ -35,7 +35,7 @@ static int z_erofs_fill_inode_lazy(struct inode *inode) 
	struct super_block *const sb = inode->i_sb;

	int err, headnr;

	erofs_off_t pos;

	struct page *page;

	struct erofs_buf buf = __EROFS_BUF_INITIALIZER;

	void *kaddr;

	struct z_erofs_map_header *h;
@@ -61,14 +61,13 @@ static int z_erofs_fill_inode_lazy(struct inode *inode) 


	pos = ALIGN(iloc(EROFS_SB(sb), vi->nid) + vi->inode_isize +

		    vi->xattr_isize, 8);

	page = erofs_get_meta_page(sb, erofs_blknr(pos));

	if (IS_ERR(page)) {

		err = PTR_ERR(page);

	kaddr = erofs_read_metabuf(&buf, sb, erofs_blknr(pos),

				   EROFS_KMAP_ATOMIC);

	if (IS_ERR(kaddr)) {

		err = PTR_ERR(kaddr);

		goto out_unlock;

	}



	kaddr = kmap_atomic(page);



	h = kaddr + erofs_blkoff(pos);

	vi->z_advise = le16_to_cpu(h->h_advise);

	vi->z_algorithmtype[0] = h->h_algorithmtype & 15;
@@ -101,20 +100,19 @@ static int z_erofs_fill_inode_lazy(struct inode *inode) 
		goto unmap_done;

	}

unmap_done:

	kunmap_atomic(kaddr);

	unlock_page(page);

	put_page(page);

	erofs_put_metabuf(&buf);

	if (err)

		goto out_unlock;



	if (vi->z_advise & Z_EROFS_ADVISE_INLINE_PCLUSTER) {

		struct erofs_map_blocks map = { .mpage = NULL };

		struct erofs_map_blocks map = {

			.buf = __EROFS_BUF_INITIALIZER

		};



		vi->z_idata_size = le16_to_cpu(h->h_idata_size);

		err = z_erofs_do_map_blocks(inode, &map,

					    EROFS_GET_BLOCKS_FINDTAIL);

		if (map.mpage)

			put_page(map.mpage);

		erofs_put_metabuf(&map.buf);



		if (!map.m_plen ||

		    erofs_blkoff(map.m_pa) + map.m_plen > EROFS_BLKSIZ) {
@@ -151,31 +149,11 @@ static int z_erofs_reload_indexes(struct z_erofs_maprecorder *m, 
				  erofs_blk_t eblk)

{

	struct super_block *const sb = m->inode->i_sb;

	struct erofs_map_blocks *const map = m->map;

	struct page *mpage = map->mpage;



	if (mpage) {

		if (mpage->index == eblk) {

			if (!m->kaddr)

				m->kaddr = kmap_atomic(mpage);

			return 0;

		}



		if (m->kaddr) {

			kunmap_atomic(m->kaddr);

			m->kaddr = NULL;

		}

		put_page(mpage);

	}



	mpage = erofs_get_meta_page(sb, eblk);

	if (IS_ERR(mpage)) {

		map->mpage = NULL;

		return PTR_ERR(mpage);

	}

	m->kaddr = kmap_atomic(mpage);

	unlock_page(mpage);

	map->mpage = mpage;

	m->kaddr = erofs_read_metabuf(&m->map->buf, sb, eblk,

				      EROFS_KMAP_ATOMIC);

	if (IS_ERR(m->kaddr))

		return PTR_ERR(m->kaddr);

	return 0;

}
@@ -711,8 +689,7 @@ static int z_erofs_do_map_blocks(struct inode *inode, 
			map->m_flags |= EROFS_MAP_FULL_MAPPED;

	}

unmap_out:

	if (m.kaddr)

		kunmap_atomic(m.kaddr);

	erofs_unmap_metabuf(&m.map->buf);



out:

	erofs_dbg("%s, m_la %llu m_pa %llu m_llen %llu m_plen %llu m_flags 0%o",
@@ -759,8 +736,7 @@ static int z_erofs_iomap_begin_report(struct inode *inode, loff_t offset, 
	struct erofs_map_blocks map = { .m_la = offset };



	ret = z_erofs_map_blocks_iter(inode, &map, EROFS_GET_BLOCKS_FIEMAP);

	if (map.mpage)

		put_page(map.mpage);

	erofs_put_metabuf(&map.buf);

	if (ret < 0)

		return ret;