[PATCH v3 2/4] erofs: support unencoded inodes for fileio
Gao Xiang
hsiangkao at linux.alibaba.com
Thu Sep 5 19:30:31 AEST 2024
Since EROFS only needs to handle read requests in simple contexts,
Just directly use vfs_iocb_iter_read() for data I/Os.
Reviewed-by: Sandeep Dhavale <dhavale at google.com>
Signed-off-by: Gao Xiang <hsiangkao at linux.alibaba.com>
---
changes since v2 (Chao):
- erofs_fileio_rq_alloc() always succeeds;
- use SECTOR_SHIFT constant.
fs/erofs/Makefile | 1 +
fs/erofs/data.c | 50 ++++++++++++-
fs/erofs/fileio.c | 177 ++++++++++++++++++++++++++++++++++++++++++++
fs/erofs/inode.c | 17 +++--
fs/erofs/internal.h | 7 +-
fs/erofs/zdata.c | 46 ++----------
6 files changed, 247 insertions(+), 51 deletions(-)
create mode 100644 fs/erofs/fileio.c
diff --git a/fs/erofs/Makefile b/fs/erofs/Makefile
index 097d672e6b14..4331d53c7109 100644
--- a/fs/erofs/Makefile
+++ b/fs/erofs/Makefile
@@ -7,4 +7,5 @@ erofs-$(CONFIG_EROFS_FS_ZIP) += decompressor.o zmap.o zdata.o zutil.o
erofs-$(CONFIG_EROFS_FS_ZIP_LZMA) += decompressor_lzma.o
erofs-$(CONFIG_EROFS_FS_ZIP_DEFLATE) += decompressor_deflate.o
erofs-$(CONFIG_EROFS_FS_ZIP_ZSTD) += decompressor_zstd.o
+erofs-$(CONFIG_EROFS_FS_BACKED_BY_FILE) += fileio.o
erofs-$(CONFIG_EROFS_FS_ONDEMAND) += fscache.o
diff --git a/fs/erofs/data.c b/fs/erofs/data.c
index 0fb31c588ae0..b4c07ce7a294 100644
--- a/fs/erofs/data.c
+++ b/fs/erofs/data.c
@@ -132,7 +132,7 @@ int erofs_map_blocks(struct inode *inode, struct erofs_map_blocks *map)
if (map->m_la >= inode->i_size) {
/* leave out-of-bound access unmapped */
map->m_flags = 0;
- map->m_plen = 0;
+ map->m_plen = map->m_llen;
goto out;
}
@@ -197,8 +197,13 @@ static void erofs_fill_from_devinfo(struct erofs_map_dev *map,
struct erofs_device_info *dif)
{
map->m_bdev = NULL;
- if (dif->file && S_ISBLK(file_inode(dif->file)->i_mode))
- map->m_bdev = file_bdev(dif->file);
+ map->m_fp = NULL;
+ if (dif->file) {
+ if (S_ISBLK(file_inode(dif->file)->i_mode))
+ map->m_bdev = file_bdev(dif->file);
+ else
+ map->m_fp = dif->file;
+ }
map->m_daxdev = dif->dax_dev;
map->m_dax_part_off = dif->dax_part_off;
map->m_fscache = dif->fscache;
@@ -215,6 +220,7 @@ int erofs_map_dev(struct super_block *sb, struct erofs_map_dev *map)
map->m_daxdev = EROFS_SB(sb)->dax_dev;
map->m_dax_part_off = EROFS_SB(sb)->dax_part_off;
map->m_fscache = EROFS_SB(sb)->s_fscache;
+ map->m_fp = EROFS_SB(sb)->fdev;
if (map->m_deviceid) {
down_read(&devs->rwsem);
@@ -250,6 +256,42 @@ int erofs_map_dev(struct super_block *sb, struct erofs_map_dev *map)
return 0;
}
+/*
+ * bit 30: I/O error occurred on this folio
+ * bit 0 - 29: remaining parts to complete this folio
+ */
+#define EROFS_ONLINEFOLIO_EIO (1 << 30)
+
+void erofs_onlinefolio_init(struct folio *folio)
+{
+ union {
+ atomic_t o;
+ void *v;
+ } u = { .o = ATOMIC_INIT(1) };
+
+ folio->private = u.v; /* valid only if file-backed folio is locked */
+}
+
+void erofs_onlinefolio_split(struct folio *folio)
+{
+ atomic_inc((atomic_t *)&folio->private);
+}
+
+void erofs_onlinefolio_end(struct folio *folio, int err)
+{
+ int orig, v;
+
+ do {
+ orig = atomic_read((atomic_t *)&folio->private);
+ v = (orig - 1) | (err ? EROFS_ONLINEFOLIO_EIO : 0);
+ } while (atomic_cmpxchg((atomic_t *)&folio->private, orig, v) != orig);
+
+ if (v & ~EROFS_ONLINEFOLIO_EIO)
+ return;
+ folio->private = 0;
+ folio_end_read(folio, !(v & EROFS_ONLINEFOLIO_EIO));
+}
+
static int erofs_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
unsigned int flags, struct iomap *iomap, struct iomap *srcmap)
{
@@ -399,7 +441,7 @@ static ssize_t erofs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
}
/* for uncompressed (aligned) files and raw access for other files */
-const struct address_space_operations erofs_raw_access_aops = {
+const struct address_space_operations erofs_aops = {
.read_folio = erofs_read_folio,
.readahead = erofs_readahead,
.bmap = erofs_bmap,
diff --git a/fs/erofs/fileio.c b/fs/erofs/fileio.c
new file mode 100644
index 000000000000..d2033d7b95e6
--- /dev/null
+++ b/fs/erofs/fileio.c
@@ -0,0 +1,177 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2024, Alibaba Cloud
+ */
+#include "internal.h"
+#include <trace/events/erofs.h>
+
+struct erofs_fileio_rq {
+ struct bio_vec bvecs[BIO_MAX_VECS];
+ struct bio bio;
+ struct kiocb iocb;
+};
+
+struct erofs_fileio {
+ struct erofs_map_blocks map;
+ struct erofs_map_dev dev;
+ struct erofs_fileio_rq *rq;
+};
+
+static void erofs_fileio_ki_complete(struct kiocb *iocb, long ret)
+{
+ struct erofs_fileio_rq *rq =
+ container_of(iocb, struct erofs_fileio_rq, iocb);
+ struct folio_iter fi;
+
+ DBG_BUGON(rq->bio.bi_end_io);
+ if (ret > 0) {
+ if (ret != rq->bio.bi_iter.bi_size) {
+ bio_advance(&rq->bio, ret);
+ zero_fill_bio(&rq->bio);
+ }
+ ret = 0;
+ }
+ bio_for_each_folio_all(fi, &rq->bio) {
+ DBG_BUGON(folio_test_uptodate(fi.folio));
+ erofs_onlinefolio_end(fi.folio, ret);
+ }
+ kfree(rq);
+}
+
+static void erofs_fileio_rq_submit(struct erofs_fileio_rq *rq)
+{
+ struct iov_iter iter;
+ int ret;
+
+ if (!rq)
+ return;
+ rq->iocb.ki_pos = rq->bio.bi_iter.bi_sector << SECTOR_SHIFT;
+ rq->iocb.ki_ioprio = get_current_ioprio();
+ rq->iocb.ki_complete = erofs_fileio_ki_complete;
+ rq->iocb.ki_flags = (rq->iocb.ki_filp->f_mode & FMODE_CAN_ODIRECT) ?
+ IOCB_DIRECT : 0;
+ iov_iter_bvec(&iter, ITER_DEST, rq->bvecs, rq->bio.bi_vcnt,
+ rq->bio.bi_iter.bi_size);
+ ret = vfs_iocb_iter_read(rq->iocb.ki_filp, &rq->iocb, &iter);
+ if (ret != -EIOCBQUEUED)
+ erofs_fileio_ki_complete(&rq->iocb, ret);
+}
+
+static struct erofs_fileio_rq *erofs_fileio_rq_alloc(struct erofs_map_dev *mdev)
+{
+ struct erofs_fileio_rq *rq = kzalloc(sizeof(*rq),
+ GFP_KERNEL | __GFP_NOFAIL);
+
+ bio_init(&rq->bio, NULL, rq->bvecs, BIO_MAX_VECS, REQ_OP_READ);
+ rq->iocb.ki_filp = mdev->m_fp;
+ return rq;
+}
+
+static int erofs_fileio_scan_folio(struct erofs_fileio *io, struct folio *folio)
+{
+ struct inode *inode = folio_inode(folio);
+ struct erofs_map_blocks *map = &io->map;
+ unsigned int cur = 0, end = folio_size(folio), len, attached = 0;
+ loff_t pos = folio_pos(folio), ofs;
+ struct iov_iter iter;
+ struct bio_vec bv;
+ int err = 0;
+
+ erofs_onlinefolio_init(folio);
+ while (cur < end) {
+ if (!in_range(pos + cur, map->m_la, map->m_llen)) {
+ map->m_la = pos + cur;
+ map->m_llen = end - cur;
+ err = erofs_map_blocks(inode, map);
+ if (err)
+ break;
+ }
+
+ ofs = folio_pos(folio) + cur - map->m_la;
+ len = min_t(loff_t, map->m_llen - ofs, end - cur);
+ if (map->m_flags & EROFS_MAP_META) {
+ struct erofs_buf buf = __EROFS_BUF_INITIALIZER;
+ void *src;
+
+ src = erofs_read_metabuf(&buf, inode->i_sb,
+ map->m_pa + ofs, EROFS_KMAP);
+ if (IS_ERR(src)) {
+ err = PTR_ERR(src);
+ break;
+ }
+ bvec_set_folio(&bv, folio, len, cur);
+ iov_iter_bvec(&iter, ITER_DEST, &bv, 1, len);
+ if (copy_to_iter(src, len, &iter) != len) {
+ erofs_put_metabuf(&buf);
+ err = -EIO;
+ break;
+ }
+ erofs_put_metabuf(&buf);
+ } else if (!(map->m_flags & EROFS_MAP_MAPPED)) {
+ folio_zero_segment(folio, cur, cur + len);
+ attached = 0;
+ } else {
+ if (io->rq && (map->m_pa + ofs != io->dev.m_pa ||
+ map->m_deviceid != io->dev.m_deviceid)) {
+io_retry:
+ erofs_fileio_rq_submit(io->rq);
+ io->rq = NULL;
+ }
+
+ if (!io->rq) {
+ io->dev = (struct erofs_map_dev) {
+ .m_pa = io->map.m_pa + ofs,
+ .m_deviceid = io->map.m_deviceid,
+ };
+ err = erofs_map_dev(inode->i_sb, &io->dev);
+ if (err)
+ break;
+ io->rq = erofs_fileio_rq_alloc(&io->dev);
+ io->rq->bio.bi_iter.bi_sector = io->dev.m_pa >> 9;
+ attached = 0;
+ }
+ if (!attached++)
+ erofs_onlinefolio_split(folio);
+ if (!bio_add_folio(&io->rq->bio, folio, len, cur))
+ goto io_retry;
+ io->dev.m_pa += len;
+ }
+ cur += len;
+ }
+ erofs_onlinefolio_end(folio, err);
+ return err;
+}
+
+static int erofs_fileio_read_folio(struct file *file, struct folio *folio)
+{
+ struct erofs_fileio io = {};
+ int err;
+
+ trace_erofs_read_folio(folio, true);
+ err = erofs_fileio_scan_folio(&io, folio);
+ erofs_fileio_rq_submit(io.rq);
+ return err;
+}
+
+static void erofs_fileio_readahead(struct readahead_control *rac)
+{
+ struct inode *inode = rac->mapping->host;
+ struct erofs_fileio io = {};
+ struct folio *folio;
+ int err;
+
+ trace_erofs_readpages(inode, readahead_index(rac),
+ readahead_count(rac), true);
+ while ((folio = readahead_folio(rac))) {
+ err = erofs_fileio_scan_folio(&io, folio);
+ if (err && err != -EINTR)
+ erofs_err(inode->i_sb, "readahead error at folio %lu @ nid %llu",
+ folio->index, EROFS_I(inode)->nid);
+ }
+ erofs_fileio_rq_submit(io.rq);
+}
+
+const struct address_space_operations erofs_fileio_aops = {
+ .read_folio = erofs_fileio_read_folio,
+ .readahead = erofs_fileio_readahead,
+};
diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c
index d05b9e59f122..4a902e6e69a5 100644
--- a/fs/erofs/inode.c
+++ b/fs/erofs/inode.c
@@ -258,11 +258,14 @@ static int erofs_fill_inode(struct inode *inode)
}
mapping_set_large_folios(inode->i_mapping);
- if (erofs_is_fileio_mode(EROFS_SB(inode->i_sb))) {
- /* XXX: data I/Os will be implemented in the following patches */
- err = -EOPNOTSUPP;
- } else if (erofs_inode_is_data_compressed(vi->datalayout)) {
+ if (erofs_inode_is_data_compressed(vi->datalayout)) {
#ifdef CONFIG_EROFS_FS_ZIP
+#ifdef CONFIG_EROFS_FS_BACKED_BY_FILE
+ if (erofs_is_fileio_mode(EROFS_SB(inode->i_sb))) {
+ err = -EOPNOTSUPP;
+ goto out_unlock;
+ }
+#endif
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!");
@@ -271,10 +274,14 @@ static int erofs_fill_inode(struct inode *inode)
err = -EOPNOTSUPP;
#endif
} else {
- inode->i_mapping->a_ops = &erofs_raw_access_aops;
+ inode->i_mapping->a_ops = &erofs_aops;
#ifdef CONFIG_EROFS_FS_ONDEMAND
if (erofs_is_fscache_mode(inode->i_sb))
inode->i_mapping->a_ops = &erofs_fscache_access_aops;
+#endif
+#ifdef CONFIG_EROFS_FS_BACKED_BY_FILE
+ if (erofs_is_fileio_mode(EROFS_SB(inode->i_sb)))
+ inode->i_mapping->a_ops = &erofs_fileio_aops;
#endif
}
out_unlock:
diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
index 9bf4fb1cfa09..9bc4dcfd06d7 100644
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -372,6 +372,7 @@ struct erofs_map_dev {
struct erofs_fscache *m_fscache;
struct block_device *m_bdev;
struct dax_device *m_daxdev;
+ struct file *m_fp;
u64 m_dax_part_off;
erofs_off_t m_pa;
@@ -380,7 +381,8 @@ struct erofs_map_dev {
extern const struct super_operations erofs_sops;
-extern const struct address_space_operations erofs_raw_access_aops;
+extern const struct address_space_operations erofs_aops;
+extern const struct address_space_operations erofs_fileio_aops;
extern const struct address_space_operations z_erofs_aops;
extern const struct address_space_operations erofs_fscache_access_aops;
@@ -411,6 +413,9 @@ 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);
int erofs_map_blocks(struct inode *inode, struct erofs_map_blocks *map);
+void erofs_onlinefolio_init(struct folio *folio);
+void erofs_onlinefolio_split(struct folio *folio);
+void erofs_onlinefolio_end(struct folio *folio, int err);
struct inode *erofs_iget(struct super_block *sb, erofs_nid_t nid);
int erofs_getattr(struct mnt_idmap *idmap, const struct path *path,
struct kstat *stat, u32 request_mask,
diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
index 424f656cd765..350612f32ac6 100644
--- a/fs/erofs/zdata.c
+++ b/fs/erofs/zdata.c
@@ -122,42 +122,6 @@ static bool erofs_folio_is_managed(struct erofs_sb_info *sbi, struct folio *fo)
return fo->mapping == MNGD_MAPPING(sbi);
}
-/*
- * bit 30: I/O error occurred on this folio
- * bit 0 - 29: remaining parts to complete this folio
- */
-#define Z_EROFS_FOLIO_EIO (1 << 30)
-
-static void z_erofs_onlinefolio_init(struct folio *folio)
-{
- union {
- atomic_t o;
- void *v;
- } u = { .o = ATOMIC_INIT(1) };
-
- folio->private = u.v; /* valid only if file-backed folio is locked */
-}
-
-static void z_erofs_onlinefolio_split(struct folio *folio)
-{
- atomic_inc((atomic_t *)&folio->private);
-}
-
-static void z_erofs_onlinefolio_end(struct folio *folio, int err)
-{
- int orig, v;
-
- do {
- orig = atomic_read((atomic_t *)&folio->private);
- v = (orig - 1) | (err ? Z_EROFS_FOLIO_EIO : 0);
- } while (atomic_cmpxchg((atomic_t *)&folio->private, orig, v) != orig);
-
- if (v & ~Z_EROFS_FOLIO_EIO)
- return;
- folio->private = 0;
- folio_end_read(folio, !(v & Z_EROFS_FOLIO_EIO));
-}
-
#define Z_EROFS_ONSTACK_PAGES 32
/*
@@ -965,7 +929,7 @@ static int z_erofs_scan_folio(struct z_erofs_decompress_frontend *f,
int err = 0;
tight = (bs == PAGE_SIZE);
- z_erofs_onlinefolio_init(folio);
+ erofs_onlinefolio_init(folio);
do {
if (offset + end - 1 < map->m_la ||
offset + end - 1 >= map->m_la + map->m_llen) {
@@ -1024,7 +988,7 @@ static int z_erofs_scan_folio(struct z_erofs_decompress_frontend *f,
if (err)
break;
- z_erofs_onlinefolio_split(folio);
+ erofs_onlinefolio_split(folio);
if (f->pcl->pageofs_out != (map->m_la & ~PAGE_MASK))
f->pcl->multibases = true;
if (f->pcl->length < offset + end - map->m_la) {
@@ -1044,7 +1008,7 @@ static int z_erofs_scan_folio(struct z_erofs_decompress_frontend *f,
tight = (bs == PAGE_SIZE);
}
} while ((end = cur) > 0);
- z_erofs_onlinefolio_end(folio, err);
+ erofs_onlinefolio_end(folio, err);
return err;
}
@@ -1147,7 +1111,7 @@ static void z_erofs_fill_other_copies(struct z_erofs_decompress_backend *be,
cur += len;
}
kunmap_local(dst);
- z_erofs_onlinefolio_end(page_folio(bvi->bvec.page), err);
+ erofs_onlinefolio_end(page_folio(bvi->bvec.page), err);
list_del(p);
kfree(bvi);
}
@@ -1302,7 +1266,7 @@ static int z_erofs_decompress_pcluster(struct z_erofs_decompress_backend *be,
DBG_BUGON(z_erofs_page_is_invalidated(page));
if (!z_erofs_is_shortlived_page(page)) {
- z_erofs_onlinefolio_end(page_folio(page), err);
+ erofs_onlinefolio_end(page_folio(page), err);
continue;
}
if (pcl->algorithmformat != Z_EROFS_COMPRESSION_LZ4) {
--
2.43.5
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