Commit a1bafc31 authored by Jingbo Xu's avatar Jingbo Xu Committed by Gao Xiang
Browse files

erofs: support compressed inodes over fscache 



Since fscache can utilize iov_iter to write dest buffers, bio_vec can
be used in this way too.

To simplify this, pseudo bios are prepared and bio_vec will be filled
with bio_add_page().  And a common .bi_end_io will be called directly
to handle I/O completions.

Signed-off-by: default avatarJingbo Xu <jefflexu@linux.alibaba.com>
Reviewed-by: default avatarGao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20240308094159.40547-2-jefflexu@linux.alibaba.com


Signed-off-by: default avatarGao Xiang <hsiangkao@linux.alibaba.com>
parent f2151df5

fs/erofs/fscache.c

+47 −0
Original line number Diff line number Diff line
@@ -174,6 +174,53 @@ static int erofs_fscache_read_io_async(struct fscache_cookie *cookie, 
	return 0;

}



struct erofs_fscache_bio {

	struct erofs_fscache_io io;

	struct bio bio;		/* w/o bdev to share bio_add_page/endio() */

	struct bio_vec bvecs[BIO_MAX_VECS];

};



static void erofs_fscache_bio_endio(void *priv,

		ssize_t transferred_or_error, bool was_async)

{

	struct erofs_fscache_bio *io = priv;



	if (IS_ERR_VALUE(transferred_or_error))

		io->bio.bi_status = errno_to_blk_status(transferred_or_error);

	io->bio.bi_end_io(&io->bio);

	BUILD_BUG_ON(offsetof(struct erofs_fscache_bio, io) != 0);

	erofs_fscache_io_put(&io->io);

}



struct bio *erofs_fscache_bio_alloc(struct erofs_map_dev *mdev)

{

	struct erofs_fscache_bio *io;



	io = kmalloc(sizeof(*io), GFP_KERNEL | __GFP_NOFAIL);

	bio_init(&io->bio, NULL, io->bvecs, BIO_MAX_VECS, REQ_OP_READ);

	io->io.private = mdev->m_fscache->cookie;

	io->io.end_io = erofs_fscache_bio_endio;

	refcount_set(&io->io.ref, 1);

	return &io->bio;

}



void erofs_fscache_submit_bio(struct bio *bio)

{

	struct erofs_fscache_bio *io = container_of(bio,

			struct erofs_fscache_bio, bio);

	int ret;



	iov_iter_bvec(&io->io.iter, ITER_DEST, io->bvecs, bio->bi_vcnt,

		      bio->bi_iter.bi_size);

	ret = erofs_fscache_read_io_async(io->io.private,

				bio->bi_iter.bi_sector << 9, &io->io);

	erofs_fscache_io_put(&io->io);

	if (!ret)

		return;

	bio->bi_status = errno_to_blk_status(ret);

	bio->bi_end_io(bio);

}



static int erofs_fscache_meta_read_folio(struct file *data, struct folio *folio)

{

	struct erofs_fscache *ctx = folio->mapping->host->i_private;

fs/erofs/inode.c

+6 −8
Original line number Diff line number Diff line
@@ -259,14 +259,12 @@ static int erofs_fill_inode(struct inode *inode) 


	if (erofs_inode_is_data_compressed(vi->datalayout)) {

#ifdef CONFIG_EROFS_FS_ZIP

		if (!erofs_is_fscache_mode(inode->i_sb)) {

			DO_ONCE_LITE_IF(inode->i_sb->s_blocksize != PAGE_SIZE,

		DO_ONCE_LITE_IF(inode->i_blkbits != PAGE_SHIFT,

			  erofs_info, inode->i_sb,

			  "EXPERIMENTAL EROFS subpage compressed block support in use. Use at your own risk!");

		inode->i_mapping->a_ops = &z_erofs_aops;

		err = 0;

		goto out_unlock;

		}

#endif

		err = -EOPNOTSUPP;

		goto out_unlock;

fs/erofs/internal.h

+4 −0
Original line number Diff line number Diff line
@@ -512,6 +512,8 @@ void erofs_fscache_unregister_fs(struct super_block *sb); 
struct erofs_fscache *erofs_fscache_register_cookie(struct super_block *sb,

					char *name, unsigned int flags);

void erofs_fscache_unregister_cookie(struct erofs_fscache *fscache);

struct bio *erofs_fscache_bio_alloc(struct erofs_map_dev *mdev);

void erofs_fscache_submit_bio(struct bio *bio);

#else

static inline int erofs_fscache_register_fs(struct super_block *sb)

{
@@ -529,6 +531,8 @@ struct erofs_fscache *erofs_fscache_register_cookie(struct super_block *sb, 
static inline void erofs_fscache_unregister_cookie(struct erofs_fscache *fscache)

{

}

static inline struct bio *erofs_fscache_bio_alloc(struct erofs_map_dev *mdev) { return NULL; }

static inline void erofs_fscache_submit_bio(struct bio *bio) {}

#endif



#define EFSCORRUPTED    EUCLEAN         /* Filesystem is corrupted */

fs/erofs/zdata.c

+20 −12
Original line number Diff line number Diff line
@@ -1561,7 +1561,7 @@ static void move_to_bypass_jobqueue(struct z_erofs_pcluster *pcl, 
	qtail[JQ_BYPASS] = &pcl->next;

}



static void z_erofs_submissionqueue_endio(struct bio *bio)

static void z_erofs_endio(struct bio *bio)

{

	struct z_erofs_decompressqueue *q = bio->bi_private;

	blk_status_t err = bio->bi_status;
@@ -1582,6 +1582,7 @@ static void z_erofs_submissionqueue_endio(struct bio *bio) 
	if (err)

		q->eio = true;

	z_erofs_decompress_kickoff(q, -1);

	if (bio->bi_bdev)

		bio_put(bio);

}
@@ -1596,7 +1597,6 @@ static void z_erofs_submit_queue(struct z_erofs_decompress_frontend *f, 
	z_erofs_next_pcluster_t owned_head = f->owned_head;

	/* bio is NULL initially, so no need to initialize last_{index,bdev} */

	erofs_off_t last_pa;

	struct block_device *last_bdev;

	unsigned int nr_bios = 0;

	struct bio *bio = NULL;

	unsigned long pflags;
@@ -1643,9 +1643,13 @@ static void z_erofs_submit_queue(struct z_erofs_decompress_frontend *f, 
				continue;



			if (bio && (cur != last_pa ||

				    last_bdev != mdev.m_bdev)) {

submit_bio_retry:

				    bio->bi_bdev != mdev.m_bdev)) {

io_retry:

				if (!erofs_is_fscache_mode(sb))

					submit_bio(bio);

				else

					erofs_fscache_submit_bio(bio);



				if (memstall) {

					psi_memstall_leave(&pflags);

					memstall = 0;
@@ -1660,15 +1664,16 @@ static void z_erofs_submit_queue(struct z_erofs_decompress_frontend *f, 
			}



			if (!bio) {

				bio = bio_alloc(mdev.m_bdev, BIO_MAX_VECS,

				bio = erofs_is_fscache_mode(sb) ?

					erofs_fscache_bio_alloc(&mdev) :

					bio_alloc(mdev.m_bdev, BIO_MAX_VECS,

						  REQ_OP_READ, GFP_NOIO);

				bio->bi_end_io = z_erofs_submissionqueue_endio;

				bio->bi_end_io = z_erofs_endio;

				bio->bi_iter.bi_sector = cur >> 9;

				bio->bi_private = q[JQ_SUBMIT];

				if (readahead)

					bio->bi_opf |= REQ_RAHEAD;

				++nr_bios;

				last_bdev = mdev.m_bdev;

			}



			if (cur + bvec.bv_len > end)
@@ -1676,7 +1681,7 @@ static void z_erofs_submit_queue(struct z_erofs_decompress_frontend *f, 
			DBG_BUGON(bvec.bv_len < sb->s_blocksize);

			if (!bio_add_page(bio, bvec.bv_page, bvec.bv_len,

					  bvec.bv_offset))

				goto submit_bio_retry;

				goto io_retry;



			last_pa = cur + bvec.bv_len;

			bypass = false;
@@ -1689,7 +1694,10 @@ static void z_erofs_submit_queue(struct z_erofs_decompress_frontend *f, 
	} while (owned_head != Z_EROFS_PCLUSTER_TAIL);



	if (bio) {

		if (!erofs_is_fscache_mode(sb))

			submit_bio(bio);

		else

			erofs_fscache_submit_bio(bio);

		if (memstall)

			psi_memstall_leave(&pflags);

	}