[PATCH v14 08/10] erofs: support unencoded inodes for page cache share

Hongbo Li posted 10 patches 1 month ago
There is a newer version of this series
[PATCH v14 08/10] erofs: support unencoded inodes for page cache share
Posted by Hongbo Li 1 month ago
This patch adds inode page cache sharing functionality for unencoded
files.

I conducted experiments in the container environment. Below is the
memory usage for reading all files in two different minor versions
of container images:

+-------------------+------------------+-------------+---------------+
|       Image       | Page Cache Share | Memory (MB) |    Memory     |
|                   |                  |             | Reduction (%) |
+-------------------+------------------+-------------+---------------+
|                   |        No        |     241     |       -       |
|       redis       +------------------+-------------+---------------+
|   7.2.4 & 7.2.5   |        Yes       |     163     |      33%      |
+-------------------+------------------+-------------+---------------+
|                   |        No        |     872     |       -       |
|      postgres     +------------------+-------------+---------------+
|    16.1 & 16.2    |        Yes       |     630     |      28%      |
+-------------------+------------------+-------------+---------------+
|                   |        No        |     2771    |       -       |
|     tensorflow    +------------------+-------------+---------------+
|  2.11.0 & 2.11.1  |        Yes       |     2340    |      16%      |
+-------------------+------------------+-------------+---------------+
|                   |        No        |     926     |       -       |
|       mysql       +------------------+-------------+---------------+
|  8.0.11 & 8.0.12  |        Yes       |     735     |      21%      |
+-------------------+------------------+-------------+---------------+
|                   |        No        |     390     |       -       |
|       nginx       +------------------+-------------+---------------+
|   7.2.4 & 7.2.5   |        Yes       |     219     |      44%      |
+-------------------+------------------+-------------+---------------+
|       tomcat      |        No        |     924     |       -       |
| 10.1.25 & 10.1.26 +------------------+-------------+---------------+
|                   |        Yes       |     474     |      49%      |
+-------------------+------------------+-------------+---------------+

Additionally, the table below shows the runtime memory usage of the
container:

+-------------------+------------------+-------------+---------------+
|       Image       | Page Cache Share | Memory (MB) |    Memory     |
|                   |                  |             | Reduction (%) |
+-------------------+------------------+-------------+---------------+
|                   |        No        |      35     |       -       |
|       redis       +------------------+-------------+---------------+
|   7.2.4 & 7.2.5   |        Yes       |      28     |      20%      |
+-------------------+------------------+-------------+---------------+
|                   |        No        |     149     |       -       |
|      postgres     +------------------+-------------+---------------+
|    16.1 & 16.2    |        Yes       |      95     |      37%      |
+-------------------+------------------+-------------+---------------+
|                   |        No        |     1028    |       -       |
|     tensorflow    +------------------+-------------+---------------+
|  2.11.0 & 2.11.1  |        Yes       |     930     |      10%      |
+-------------------+------------------+-------------+---------------+
|                   |        No        |     155     |       -       |
|       mysql       +------------------+-------------+---------------+
|  8.0.11 & 8.0.12  |        Yes       |     132     |      15%      |
+-------------------+------------------+-------------+---------------+
|                   |        No        |      25     |       -       |
|       nginx       +------------------+-------------+---------------+
|   7.2.4 & 7.2.5   |        Yes       |      20     |      20%      |
+-------------------+------------------+-------------+---------------+
|       tomcat      |        No        |     186     |       -       |
| 10.1.25 & 10.1.26 +------------------+-------------+---------------+
|                   |        Yes       |      98     |      48%      |
+-------------------+------------------+-------------+---------------+

Co-developed-by: Hongzhen Luo <hongzhen@linux.alibaba.com>
Signed-off-by: Hongzhen Luo <hongzhen@linux.alibaba.com>
Signed-off-by: Hongbo Li <lihongbo22@huawei.com>
---
 fs/erofs/data.c              | 32 +++++++++++++++++++++++---------
 fs/erofs/fileio.c            | 25 ++++++++++++++++---------
 fs/erofs/inode.c             |  2 ++
 fs/erofs/internal.h          |  6 ++++++
 fs/erofs/ishare.c            | 34 ++++++++++++++++++++++++++++++++++
 fs/erofs/zdata.c             |  2 +-
 include/trace/events/erofs.h | 10 +++++-----
 7 files changed, 87 insertions(+), 24 deletions(-)

diff --git a/fs/erofs/data.c b/fs/erofs/data.c
index 71e23d91123d..7bbd94781170 100644
--- a/fs/erofs/data.c
+++ b/fs/erofs/data.c
@@ -269,6 +269,7 @@ void erofs_onlinefolio_end(struct folio *folio, int err, bool dirty)
 struct erofs_iomap_iter_ctx {
 	struct page *page;
 	void *base;
+	struct inode *realinode;
 };
 
 static int erofs_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
@@ -276,14 +277,15 @@ static int erofs_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
 {
 	struct iomap_iter *iter = container_of(iomap, struct iomap_iter, iomap);
 	struct erofs_iomap_iter_ctx *ctx = iter->private;
-	struct super_block *sb = inode->i_sb;
+	struct inode *realinode = ctx ? ctx->realinode : inode;
+	struct super_block *sb = realinode->i_sb;
 	struct erofs_map_blocks map;
 	struct erofs_map_dev mdev;
 	int ret;
 
 	map.m_la = offset;
 	map.m_llen = length;
-	ret = erofs_map_blocks(inode, &map);
+	ret = erofs_map_blocks(realinode, &map);
 	if (ret < 0)
 		return ret;
 
@@ -296,7 +298,7 @@ static int erofs_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
 		return 0;
 	}
 
-	if (!(map.m_flags & EROFS_MAP_META) || !erofs_inode_in_metabox(inode)) {
+	if (!(map.m_flags & EROFS_MAP_META) || !erofs_inode_in_metabox(realinode)) {
 		mdev = (struct erofs_map_dev) {
 			.m_deviceid = map.m_deviceid,
 			.m_pa = map.m_pa,
@@ -322,7 +324,7 @@ static int erofs_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
 			void *ptr;
 
 			ptr = erofs_read_metabuf(&buf, sb, map.m_pa,
-						 erofs_inode_in_metabox(inode));
+						 erofs_inode_in_metabox(realinode));
 			if (IS_ERR(ptr))
 				return PTR_ERR(ptr);
 			iomap->inline_data = ptr;
@@ -383,11 +385,16 @@ static int erofs_read_folio(struct file *file, struct folio *folio)
 		.ops		= &iomap_bio_read_ops,
 		.cur_folio	= folio,
 	};
-	struct erofs_iomap_iter_ctx iter_ctx = {};
+	bool need_iput;
+	struct erofs_iomap_iter_ctx iter_ctx = {
+		.realinode = erofs_real_inode(folio_inode(folio), &need_iput),
+	};
 
-	trace_erofs_read_folio(folio, true);
+	trace_erofs_read_folio(iter_ctx.realinode, folio, true);
 
 	iomap_read_folio(&erofs_iomap_ops, &read_ctx, &iter_ctx);
+	if (need_iput)
+		iput(iter_ctx.realinode);
 	return 0;
 }
 
@@ -397,12 +404,17 @@ static void erofs_readahead(struct readahead_control *rac)
 		.ops		= &iomap_bio_read_ops,
 		.rac		= rac,
 	};
-	struct erofs_iomap_iter_ctx iter_ctx = {};
+	bool need_iput;
+	struct erofs_iomap_iter_ctx iter_ctx = {
+		.realinode = erofs_real_inode(rac->mapping->host, &need_iput),
+	};
 
-	trace_erofs_readahead(rac->mapping->host, readahead_index(rac),
+	trace_erofs_readahead(iter_ctx.realinode, readahead_index(rac),
 					readahead_count(rac), true);
 
 	iomap_readahead(&erofs_iomap_ops, &read_ctx, &iter_ctx);
+	if (need_iput)
+		iput(iter_ctx.realinode);
 }
 
 static sector_t erofs_bmap(struct address_space *mapping, sector_t block)
@@ -423,7 +435,9 @@ static ssize_t erofs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
 		return dax_iomap_rw(iocb, to, &erofs_iomap_ops);
 #endif
 	if ((iocb->ki_flags & IOCB_DIRECT) && inode->i_sb->s_bdev) {
-		struct erofs_iomap_iter_ctx iter_ctx = {};
+		struct erofs_iomap_iter_ctx iter_ctx = {
+			.realinode = inode,
+		};
 
 		return iomap_dio_rw(iocb, to, &erofs_iomap_ops,
 				    NULL, 0, &iter_ctx, 0);
diff --git a/fs/erofs/fileio.c b/fs/erofs/fileio.c
index 932e8b353ba1..c1d0081609dc 100644
--- a/fs/erofs/fileio.c
+++ b/fs/erofs/fileio.c
@@ -88,9 +88,9 @@ void erofs_fileio_submit_bio(struct bio *bio)
 						   bio));
 }
 
-static int erofs_fileio_scan_folio(struct erofs_fileio *io, struct folio *folio)
+static int erofs_fileio_scan_folio(struct erofs_fileio *io,
+				   struct inode *inode, 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;
@@ -158,31 +158,38 @@ static int erofs_fileio_scan_folio(struct erofs_fileio *io, struct folio *folio)
 
 static int erofs_fileio_read_folio(struct file *file, struct folio *folio)
 {
+	bool need_iput;
+	struct inode *realinode = erofs_real_inode(folio_inode(folio), &need_iput);
 	struct erofs_fileio io = {};
 	int err;
 
-	trace_erofs_read_folio(folio, true);
-	err = erofs_fileio_scan_folio(&io, folio);
+	trace_erofs_read_folio(realinode, folio, true);
+	err = erofs_fileio_scan_folio(&io, realinode, folio);
 	erofs_fileio_rq_submit(io.rq);
+	if (need_iput)
+		iput(realinode);
 	return err;
 }
 
 static void erofs_fileio_readahead(struct readahead_control *rac)
 {
-	struct inode *inode = rac->mapping->host;
+	bool need_iput;
+	struct inode *realinode = erofs_real_inode(rac->mapping->host, &need_iput);
 	struct erofs_fileio io = {};
 	struct folio *folio;
 	int err;
 
-	trace_erofs_readahead(inode, readahead_index(rac),
+	trace_erofs_readahead(realinode, readahead_index(rac),
 			      readahead_count(rac), true);
 	while ((folio = readahead_folio(rac))) {
-		err = erofs_fileio_scan_folio(&io, folio);
+		err = erofs_fileio_scan_folio(&io, realinode, folio);
 		if (err && err != -EINTR)
-			erofs_err(inode->i_sb, "readahead error at folio %lu @ nid %llu",
-				  folio->index, EROFS_I(inode)->nid);
+			erofs_err(realinode->i_sb, "readahead error at folio %lu @ nid %llu",
+				  folio->index, EROFS_I(realinode)->nid);
 	}
 	erofs_fileio_rq_submit(io.rq);
+	if (need_iput)
+		iput(realinode);
 }
 
 const struct address_space_operations erofs_fileio_aops = {
diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c
index bce98c845a18..52179b706b5b 100644
--- a/fs/erofs/inode.c
+++ b/fs/erofs/inode.c
@@ -215,6 +215,8 @@ static int erofs_fill_inode(struct inode *inode)
 	case S_IFREG:
 		inode->i_op = &erofs_generic_iops;
 		inode->i_fop = &erofs_file_fops;
+		if (erofs_ishare_fill_inode(inode))
+			inode->i_fop = &erofs_ishare_fops;
 		break;
 	case S_IFDIR:
 		inode->i_op = &erofs_dir_iops;
diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
index 810fc4675091..3658159eab00 100644
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -565,11 +565,17 @@ int __init erofs_init_ishare(void);
 void erofs_exit_ishare(void);
 bool erofs_ishare_fill_inode(struct inode *inode);
 void erofs_ishare_free_inode(struct inode *inode);
+struct inode *erofs_real_inode(struct inode *inode, bool *need_iput);
 #else
 static inline int erofs_init_ishare(void) { return 0; }
 static inline void erofs_exit_ishare(void) {}
 static inline bool erofs_ishare_fill_inode(struct inode *inode) { return false; }
 static inline void erofs_ishare_free_inode(struct inode *inode) {}
+static inline struct inode *erofs_real_inode(struct inode *inode, bool *need_iput)
+{
+	*need_iput = false;
+	return inode;
+}
 #endif
 
 long erofs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg);
diff --git a/fs/erofs/ishare.c b/fs/erofs/ishare.c
index 36d9d5922a75..24bbd6a7a900 100644
--- a/fs/erofs/ishare.c
+++ b/fs/erofs/ishare.c
@@ -11,6 +11,12 @@
 
 static struct vfsmount *erofs_ishare_mnt;
 
+static inline bool erofs_is_ishare_inode(struct inode *inode)
+{
+	/* assumed FS_ONDEMAND is excluded with FS_PAGE_CACHE_SHARE feature */
+	return inode->i_sb->s_type == &erofs_anon_fs_type;
+}
+
 static int erofs_ishare_iget5_eq(struct inode *inode, void *data)
 {
 	struct erofs_inode_fingerprint *fp1 = &EROFS_I(inode)->fingerprint;
@@ -38,6 +44,8 @@ bool erofs_ishare_fill_inode(struct inode *inode)
 	struct inode *sharedinode;
 	unsigned long hash;
 
+	if (erofs_inode_is_data_compressed(vi->datalayout))
+		return false;
 	if (erofs_xattr_fill_inode_fingerprint(&fp, inode, sbi->domain_id))
 		return false;
 	hash = xxh32(fp.opaque, fp.size, 0);
@@ -153,6 +161,32 @@ const struct file_operations erofs_ishare_fops = {
 	.splice_read	= filemap_splice_read,
 };
 
+struct inode *erofs_real_inode(struct inode *inode, bool *need_iput)
+{
+	struct erofs_inode *vi, *vi_share;
+	struct inode *realinode;
+
+	*need_iput = false;
+	if (!erofs_is_ishare_inode(inode))
+		return inode;
+
+	vi_share = EROFS_I(inode);
+	spin_lock(&vi_share->ishare_lock);
+	/* fetch any one as real inode */
+	DBG_BUGON(list_empty(&vi_share->ishare_list));
+	list_for_each_entry(vi, &vi_share->ishare_list, ishare_list) {
+		realinode = igrab(&vi->vfs_inode);
+		if (realinode) {
+			*need_iput = true;
+			break;
+		}
+	}
+	spin_unlock(&vi_share->ishare_lock);
+
+	DBG_BUGON(!realinode);
+	return realinode;
+}
+
 int __init erofs_init_ishare(void)
 {
 	erofs_ishare_mnt = kern_mount(&erofs_anon_fs_type);
diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
index 3d31f7840ca0..93ab6a481b64 100644
--- a/fs/erofs/zdata.c
+++ b/fs/erofs/zdata.c
@@ -1887,7 +1887,7 @@ static int z_erofs_read_folio(struct file *file, struct folio *folio)
 	Z_EROFS_DEFINE_FRONTEND(f, inode, folio_pos(folio));
 	int err;
 
-	trace_erofs_read_folio(folio, false);
+	trace_erofs_read_folio(inode, folio, false);
 	z_erofs_pcluster_readmore(&f, NULL, true);
 	err = z_erofs_scan_folio(&f, folio, false);
 	z_erofs_pcluster_readmore(&f, NULL, false);
diff --git a/include/trace/events/erofs.h b/include/trace/events/erofs.h
index dad7360f42f9..def20d06507b 100644
--- a/include/trace/events/erofs.h
+++ b/include/trace/events/erofs.h
@@ -82,9 +82,9 @@ TRACE_EVENT(erofs_fill_inode,
 
 TRACE_EVENT(erofs_read_folio,
 
-	TP_PROTO(struct folio *folio, bool raw),
+	TP_PROTO(struct inode *inode, struct folio *folio, bool raw),
 
-	TP_ARGS(folio, raw),
+	TP_ARGS(inode, folio, raw),
 
 	TP_STRUCT__entry(
 		__field(dev_t,		dev	)
@@ -96,9 +96,9 @@ TRACE_EVENT(erofs_read_folio,
 	),
 
 	TP_fast_assign(
-		__entry->dev	= folio->mapping->host->i_sb->s_dev;
-		__entry->nid	= EROFS_I(folio->mapping->host)->nid;
-		__entry->dir	= S_ISDIR(folio->mapping->host->i_mode);
+		__entry->dev	= inode->i_sb->s_dev;
+		__entry->nid	= EROFS_I(inode)->nid;
+		__entry->dir	= S_ISDIR(inode->i_mode);
 		__entry->index	= folio->index;
 		__entry->uptodate = folio_test_uptodate(folio);
 		__entry->raw = raw;
-- 
2.22.0
Re: [PATCH v14 08/10] erofs: support unencoded inodes for page cache share
Posted by Gao Xiang 3 weeks, 5 days ago

On 2026/1/9 18:28, Hongbo Li wrote:
> This patch adds inode page cache sharing functionality for unencoded
> files.
> 
> I conducted experiments in the container environment. Below is the
> memory usage for reading all files in two different minor versions
> of container images:
> 
> +-------------------+------------------+-------------+---------------+
> |       Image       | Page Cache Share | Memory (MB) |    Memory     |
> |                   |                  |             | Reduction (%) |
> +-------------------+------------------+-------------+---------------+
> |                   |        No        |     241     |       -       |
> |       redis       +------------------+-------------+---------------+
> |   7.2.4 & 7.2.5   |        Yes       |     163     |      33%      |
> +-------------------+------------------+-------------+---------------+
> |                   |        No        |     872     |       -       |
> |      postgres     +------------------+-------------+---------------+
> |    16.1 & 16.2    |        Yes       |     630     |      28%      |
> +-------------------+------------------+-------------+---------------+
> |                   |        No        |     2771    |       -       |
> |     tensorflow    +------------------+-------------+---------------+
> |  2.11.0 & 2.11.1  |        Yes       |     2340    |      16%      |
> +-------------------+------------------+-------------+---------------+
> |                   |        No        |     926     |       -       |
> |       mysql       +------------------+-------------+---------------+
> |  8.0.11 & 8.0.12  |        Yes       |     735     |      21%      |
> +-------------------+------------------+-------------+---------------+
> |                   |        No        |     390     |       -       |
> |       nginx       +------------------+-------------+---------------+
> |   7.2.4 & 7.2.5   |        Yes       |     219     |      44%      |
> +-------------------+------------------+-------------+---------------+
> |       tomcat      |        No        |     924     |       -       |
> | 10.1.25 & 10.1.26 +------------------+-------------+---------------+
> |                   |        Yes       |     474     |      49%      |
> +-------------------+------------------+-------------+---------------+
> 
> Additionally, the table below shows the runtime memory usage of the
> container:
> 
> +-------------------+------------------+-------------+---------------+
> |       Image       | Page Cache Share | Memory (MB) |    Memory     |
> |                   |                  |             | Reduction (%) |
> +-------------------+------------------+-------------+---------------+
> |                   |        No        |      35     |       -       |
> |       redis       +------------------+-------------+---------------+
> |   7.2.4 & 7.2.5   |        Yes       |      28     |      20%      |
> +-------------------+------------------+-------------+---------------+
> |                   |        No        |     149     |       -       |
> |      postgres     +------------------+-------------+---------------+
> |    16.1 & 16.2    |        Yes       |      95     |      37%      |
> +-------------------+------------------+-------------+---------------+
> |                   |        No        |     1028    |       -       |
> |     tensorflow    +------------------+-------------+---------------+
> |  2.11.0 & 2.11.1  |        Yes       |     930     |      10%      |
> +-------------------+------------------+-------------+---------------+
> |                   |        No        |     155     |       -       |
> |       mysql       +------------------+-------------+---------------+
> |  8.0.11 & 8.0.12  |        Yes       |     132     |      15%      |
> +-------------------+------------------+-------------+---------------+
> |                   |        No        |      25     |       -       |
> |       nginx       +------------------+-------------+---------------+
> |   7.2.4 & 7.2.5   |        Yes       |      20     |      20%      |
> +-------------------+------------------+-------------+---------------+
> |       tomcat      |        No        |     186     |       -       |
> | 10.1.25 & 10.1.26 +------------------+-------------+---------------+
> |                   |        Yes       |      98     |      48%      |
> +-------------------+------------------+-------------+---------------+
> 
> Co-developed-by: Hongzhen Luo <hongzhen@linux.alibaba.com>
> Signed-off-by: Hongzhen Luo <hongzhen@linux.alibaba.com>
> Signed-off-by: Hongbo Li <lihongbo22@huawei.com>
> ---
>   fs/erofs/data.c              | 32 +++++++++++++++++++++++---------
>   fs/erofs/fileio.c            | 25 ++++++++++++++++---------
>   fs/erofs/inode.c             |  2 ++
>   fs/erofs/internal.h          |  6 ++++++
>   fs/erofs/ishare.c            | 34 ++++++++++++++++++++++++++++++++++
>   fs/erofs/zdata.c             |  2 +-
>   include/trace/events/erofs.h | 10 +++++-----
>   7 files changed, 87 insertions(+), 24 deletions(-)
> 
> diff --git a/fs/erofs/data.c b/fs/erofs/data.c
> index 71e23d91123d..7bbd94781170 100644
> --- a/fs/erofs/data.c
> +++ b/fs/erofs/data.c
> @@ -269,6 +269,7 @@ void erofs_onlinefolio_end(struct folio *folio, int err, bool dirty)
>   struct erofs_iomap_iter_ctx {
>   	struct page *page;
>   	void *base;
> +	struct inode *realinode;
>   };
>   
>   static int erofs_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
> @@ -276,14 +277,15 @@ static int erofs_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
>   {
>   	struct iomap_iter *iter = container_of(iomap, struct iomap_iter, iomap);
>   	struct erofs_iomap_iter_ctx *ctx = iter->private;
> -	struct super_block *sb = inode->i_sb;
> +	struct inode *realinode = ctx ? ctx->realinode : inode;
> +	struct super_block *sb = realinode->i_sb;
>   	struct erofs_map_blocks map;
>   	struct erofs_map_dev mdev;
>   	int ret;
>   
>   	map.m_la = offset;
>   	map.m_llen = length;
> -	ret = erofs_map_blocks(inode, &map);
> +	ret = erofs_map_blocks(realinode, &map);
>   	if (ret < 0)
>   		return ret;
>   
> @@ -296,7 +298,7 @@ static int erofs_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
>   		return 0;
>   	}
>   
> -	if (!(map.m_flags & EROFS_MAP_META) || !erofs_inode_in_metabox(inode)) {
> +	if (!(map.m_flags & EROFS_MAP_META) || !erofs_inode_in_metabox(realinode)) {
>   		mdev = (struct erofs_map_dev) {
>   			.m_deviceid = map.m_deviceid,
>   			.m_pa = map.m_pa,
> @@ -322,7 +324,7 @@ static int erofs_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
>   			void *ptr;
>   
>   			ptr = erofs_read_metabuf(&buf, sb, map.m_pa,
> -						 erofs_inode_in_metabox(inode));
> +						 erofs_inode_in_metabox(realinode));
>   			if (IS_ERR(ptr))
>   				return PTR_ERR(ptr);
>   			iomap->inline_data = ptr;
> @@ -383,11 +385,16 @@ static int erofs_read_folio(struct file *file, struct folio *folio)
>   		.ops		= &iomap_bio_read_ops,
>   		.cur_folio	= folio,
>   	};
> -	struct erofs_iomap_iter_ctx iter_ctx = {};
> +	bool need_iput;
> +	struct erofs_iomap_iter_ctx iter_ctx = {
> +		.realinode = erofs_real_inode(folio_inode(folio), &need_iput),
> +	};
>   
> -	trace_erofs_read_folio(folio, true);
> +	trace_erofs_read_folio(iter_ctx.realinode, folio, true);
>   
>   	iomap_read_folio(&erofs_iomap_ops, &read_ctx, &iter_ctx);
> +	if (need_iput)
> +		iput(iter_ctx.realinode);
>   	return 0;
>   }
>   
> @@ -397,12 +404,17 @@ static void erofs_readahead(struct readahead_control *rac)
>   		.ops		= &iomap_bio_read_ops,
>   		.rac		= rac,
>   	};
> -	struct erofs_iomap_iter_ctx iter_ctx = {};
> +	bool need_iput;
> +	struct erofs_iomap_iter_ctx iter_ctx = {
> +		.realinode = erofs_real_inode(rac->mapping->host, &need_iput),
> +	};
>   
> -	trace_erofs_readahead(rac->mapping->host, readahead_index(rac),
> +	trace_erofs_readahead(iter_ctx.realinode, readahead_index(rac),
>   					readahead_count(rac), true);

Is it possible to add a commit to update the tracepoints
to add the new realinode first?

Also please fix the indentation in that commit together.

>   
>   	iomap_readahead(&erofs_iomap_ops, &read_ctx, &iter_ctx);
> +	if (need_iput)
> +		iput(iter_ctx.realinode);
>   }
>   
>   static sector_t erofs_bmap(struct address_space *mapping, sector_t block)
> @@ -423,7 +435,9 @@ static ssize_t erofs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
>   		return dax_iomap_rw(iocb, to, &erofs_iomap_ops);
>   #endif
>   	if ((iocb->ki_flags & IOCB_DIRECT) && inode->i_sb->s_bdev) {
> -		struct erofs_iomap_iter_ctx iter_ctx = {};
> +		struct erofs_iomap_iter_ctx iter_ctx = {
> +			.realinode = inode,
> +		};
>   
>   		return iomap_dio_rw(iocb, to, &erofs_iomap_ops,
>   				    NULL, 0, &iter_ctx, 0);
> diff --git a/fs/erofs/fileio.c b/fs/erofs/fileio.c
> index 932e8b353ba1..c1d0081609dc 100644
> --- a/fs/erofs/fileio.c
> +++ b/fs/erofs/fileio.c
> @@ -88,9 +88,9 @@ void erofs_fileio_submit_bio(struct bio *bio)
>   						   bio));
>   }
>   
> -static int erofs_fileio_scan_folio(struct erofs_fileio *io, struct folio *folio)
> +static int erofs_fileio_scan_folio(struct erofs_fileio *io,
> +				   struct inode *inode, 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;
> @@ -158,31 +158,38 @@ static int erofs_fileio_scan_folio(struct erofs_fileio *io, struct folio *folio)
>   
>   static int erofs_fileio_read_folio(struct file *file, struct folio *folio)
>   {
> +	bool need_iput;
> +	struct inode *realinode = erofs_real_inode(folio_inode(folio), &need_iput);
>   	struct erofs_fileio io = {};
>   	int err;
>   
> -	trace_erofs_read_folio(folio, true);
> -	err = erofs_fileio_scan_folio(&io, folio);
> +	trace_erofs_read_folio(realinode, folio, true);
> +	err = erofs_fileio_scan_folio(&io, realinode, folio);
>   	erofs_fileio_rq_submit(io.rq);
> +	if (need_iput)
> +		iput(realinode);
>   	return err;
>   }
>   
>   static void erofs_fileio_readahead(struct readahead_control *rac)
>   {
> -	struct inode *inode = rac->mapping->host;
> +	bool need_iput;
> +	struct inode *realinode = erofs_real_inode(rac->mapping->host, &need_iput);
>   	struct erofs_fileio io = {};
>   	struct folio *folio;
>   	int err;
>   
> -	trace_erofs_readahead(inode, readahead_index(rac),
> +	trace_erofs_readahead(realinode, readahead_index(rac),
>   			      readahead_count(rac), true);
>   	while ((folio = readahead_folio(rac))) {
> -		err = erofs_fileio_scan_folio(&io, folio);
> +		err = erofs_fileio_scan_folio(&io, realinode, folio);
>   		if (err && err != -EINTR)
> -			erofs_err(inode->i_sb, "readahead error at folio %lu @ nid %llu",
> -				  folio->index, EROFS_I(inode)->nid);
> +			erofs_err(realinode->i_sb, "readahead error at folio %lu @ nid %llu",
> +				  folio->index, EROFS_I(realinode)->nid);
>   	}
>   	erofs_fileio_rq_submit(io.rq);
> +	if (need_iput)
> +		iput(realinode);
>   }
>   
>   const struct address_space_operations erofs_fileio_aops = {
> diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c
> index bce98c845a18..52179b706b5b 100644
> --- a/fs/erofs/inode.c
> +++ b/fs/erofs/inode.c
> @@ -215,6 +215,8 @@ static int erofs_fill_inode(struct inode *inode)
>   	case S_IFREG:
>   		inode->i_op = &erofs_generic_iops;
>   		inode->i_fop = &erofs_file_fops;
> +		if (erofs_ishare_fill_inode(inode))
> +			inode->i_fop = &erofs_ishare_fops;

		inode->i_fop = erofs_ishare_fill_inode(inode) ?
			&erofs_ishare_fops : &erofs_file_fops;

Otherwise it looks good to me.

Thanks,
Gao Xiang
Re: [PATCH v14 08/10] erofs: support unencoded inodes for page cache share
Posted by Hongbo Li 3 weeks, 4 days ago
Hi,Xiang

On 2026/1/14 22:51, Gao Xiang wrote:
> 
> 
> On 2026/1/9 18:28, Hongbo Li wrote:
>> This patch adds inode page cache sharing functionality for unencoded
>> files.
>>
>> I conducted experiments in the container environment. Below is the

...
>>               iomap->inline_data = ptr;
>> @@ -383,11 +385,16 @@ static int erofs_read_folio(struct file *file, 
>> struct folio *folio)
>>           .ops        = &iomap_bio_read_ops,
>>           .cur_folio    = folio,
>>       };
>> -    struct erofs_iomap_iter_ctx iter_ctx = {};
>> +    bool need_iput;
>> +    struct erofs_iomap_iter_ctx iter_ctx = {
>> +        .realinode = erofs_real_inode(folio_inode(folio), &need_iput),
>> +    };
>> -    trace_erofs_read_folio(folio, true);
>> +    trace_erofs_read_folio(iter_ctx.realinode, folio, true);
>>       iomap_read_folio(&erofs_iomap_ops, &read_ctx, &iter_ctx);
>> +    if (need_iput)
>> +        iput(iter_ctx.realinode);
>>       return 0;
>>   }
>> @@ -397,12 +404,17 @@ static void erofs_readahead(struct 
>> readahead_control *rac)
>>           .ops        = &iomap_bio_read_ops,
>>           .rac        = rac,
>>       };
>> -    struct erofs_iomap_iter_ctx iter_ctx = {};
>> +    bool need_iput;
>> +    struct erofs_iomap_iter_ctx iter_ctx = {
>> +        .realinode = erofs_real_inode(rac->mapping->host, &need_iput),
>> +    };
>> -    trace_erofs_readahead(rac->mapping->host, readahead_index(rac),
>> +    trace_erofs_readahead(iter_ctx.realinode, readahead_index(rac),
>>                       readahead_count(rac), true);
> 
> Is it possible to add a commit to update the tracepoints
> to add the new realinode first?

Yeah, so should we put the update on trace_erofs_read_folio and 
trace_erofs_readahead in a single patch after "[PATCH v14 03/10] fs: 
Export alloc_empty_backing_file"?

  Since the first two patches in this series has merged in vfs tree 
(thanks Christian), should we reorder the left patches?

Thanks,
Hongbo


> 
> Also please fix the indentation in that commit together.
> 
>>       iomap_readahead(&erofs_iomap_ops, &read_ctx, &iter_ctx);
>> +    if (need_iput)
>> +        iput(iter_ctx.realinode);
>>   }
>>   static sector_t erofs_bmap(struct address_space *mapping, sector_t 
>> block)
>> @@ -423,7 +435,9 @@ static ssize_t erofs_file_read_iter(struct kiocb 

...
>>   }
>>   const struct address_space_operations erofs_fileio_aops = {
>> diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c
>> index bce98c845a18..52179b706b5b 100644
>> --- a/fs/erofs/inode.c
>> +++ b/fs/erofs/inode.c
>> @@ -215,6 +215,8 @@ static int erofs_fill_inode(struct inode *inode)
>>       case S_IFREG:
>>           inode->i_op = &erofs_generic_iops;
>>           inode->i_fop = &erofs_file_fops;
>> +        if (erofs_ishare_fill_inode(inode))
>> +            inode->i_fop = &erofs_ishare_fops;
> 
>          inode->i_fop = erofs_ishare_fill_inode(inode) ?
>              &erofs_ishare_fops : &erofs_file_fops;

Ok, will update.

> 
> Otherwise it looks good to me.
> 
> Thanks,
> Gao Xiang
Re: [PATCH v14 08/10] erofs: support unencoded inodes for page cache share
Posted by Gao Xiang 3 weeks, 4 days ago

On 2026/1/15 09:36, Hongbo Li wrote:
> Hi,Xiang
> 
> On 2026/1/14 22:51, Gao Xiang wrote:
>>
>>
>> On 2026/1/9 18:28, Hongbo Li wrote:
>>> This patch adds inode page cache sharing functionality for unencoded
>>> files.
>>>
>>> I conducted experiments in the container environment. Below is the
> 
> ...
>>>               iomap->inline_data = ptr;
>>> @@ -383,11 +385,16 @@ static int erofs_read_folio(struct file *file, struct folio *folio)
>>>           .ops        = &iomap_bio_read_ops,
>>>           .cur_folio    = folio,
>>>       };
>>> -    struct erofs_iomap_iter_ctx iter_ctx = {};
>>> +    bool need_iput;
>>> +    struct erofs_iomap_iter_ctx iter_ctx = {
>>> +        .realinode = erofs_real_inode(folio_inode(folio), &need_iput),
>>> +    };
>>> -    trace_erofs_read_folio(folio, true);
>>> +    trace_erofs_read_folio(iter_ctx.realinode, folio, true);
>>>       iomap_read_folio(&erofs_iomap_ops, &read_ctx, &iter_ctx);
>>> +    if (need_iput)
>>> +        iput(iter_ctx.realinode);
>>>       return 0;
>>>   }
>>> @@ -397,12 +404,17 @@ static void erofs_readahead(struct readahead_control *rac)
>>>           .ops        = &iomap_bio_read_ops,
>>>           .rac        = rac,
>>>       };
>>> -    struct erofs_iomap_iter_ctx iter_ctx = {};
>>> +    bool need_iput;
>>> +    struct erofs_iomap_iter_ctx iter_ctx = {
>>> +        .realinode = erofs_real_inode(rac->mapping->host, &need_iput),
>>> +    };
>>> -    trace_erofs_readahead(rac->mapping->host, readahead_index(rac),
>>> +    trace_erofs_readahead(iter_ctx.realinode, readahead_index(rac),
>>>                       readahead_count(rac), true);
>>
>> Is it possible to add a commit to update the tracepoints
>> to add the new realinode first?
> 
> Yeah, so should we put the update on trace_erofs_read_folio and trace_erofs_readahead in a single patch after "[PATCH v14 03/10] fs: Export alloc_empty_backing_file"?

I think the tracepoint one should be just before this patch.

> 
>   Since the first two patches in this series has merged in vfs tree (thanks Christian), should we reorder the left patches?

I think you just send the new patchset version
in the future without the first two patches
in the version.

Thanks,
Gao Xiang

> 
> Thanks,
> Hongbo
> 
Re: [PATCH v14 08/10] erofs: support unencoded inodes for page cache share
Posted by Hongbo Li 3 weeks, 4 days ago

On 2026/1/15 9:46, Gao Xiang wrote:
> 
> 
> On 2026/1/15 09:36, Hongbo Li wrote:
>> Hi,Xiang
>>
>> On 2026/1/14 22:51, Gao Xiang wrote:
>>>
>>>
>>> On 2026/1/9 18:28, Hongbo Li wrote:
>>>> This patch adds inode page cache sharing functionality for unencoded
>>>> files.
>>>>
>>>> I conducted experiments in the container environment. Below is the
>>
>> ...
>>>>               iomap->inline_data = ptr;
>>>> @@ -383,11 +385,16 @@ static int erofs_read_folio(struct file *file, 
>>>> struct folio *folio)
>>>>           .ops        = &iomap_bio_read_ops,
>>>>           .cur_folio    = folio,
>>>>       };
>>>> -    struct erofs_iomap_iter_ctx iter_ctx = {};
>>>> +    bool need_iput;
>>>> +    struct erofs_iomap_iter_ctx iter_ctx = {
>>>> +        .realinode = erofs_real_inode(folio_inode(folio), &need_iput),
>>>> +    };
>>>> -    trace_erofs_read_folio(folio, true);
>>>> +    trace_erofs_read_folio(iter_ctx.realinode, folio, true);
>>>>       iomap_read_folio(&erofs_iomap_ops, &read_ctx, &iter_ctx);
>>>> +    if (need_iput)
>>>> +        iput(iter_ctx.realinode);
>>>>       return 0;
>>>>   }
>>>> @@ -397,12 +404,17 @@ static void erofs_readahead(struct 
>>>> readahead_control *rac)
>>>>           .ops        = &iomap_bio_read_ops,
>>>>           .rac        = rac,
>>>>       };
>>>> -    struct erofs_iomap_iter_ctx iter_ctx = {};
>>>> +    bool need_iput;
>>>> +    struct erofs_iomap_iter_ctx iter_ctx = {
>>>> +        .realinode = erofs_real_inode(rac->mapping->host, &need_iput),
>>>> +    };
>>>> -    trace_erofs_readahead(rac->mapping->host, readahead_index(rac),
>>>> +    trace_erofs_readahead(iter_ctx.realinode, readahead_index(rac),
>>>>                       readahead_count(rac), true);
>>>
>>> Is it possible to add a commit to update the tracepoints
>>> to add the new realinode first?
>>
>> Yeah, so should we put the update on trace_erofs_read_folio and 
>> trace_erofs_readahead in a single patch after "[PATCH v14 03/10] fs: 
>> Export alloc_empty_backing_file"?
> 
> I think the tracepoint one should be just before this patch.
> 
>>
>>   Since the first two patches in this series has merged in vfs tree 
>> (thanks Christian), should we reorder the left patches?
> 
> I think you just send the new patchset version
> in the future without the first two patches
> in the version.
> 

Ok,

Thanks,
Hongbo

> Thanks,
> Gao Xiang
> 
>>
>> Thanks,
>> Hongbo
>>