| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <96569039-1d93-45bc-a0e0-631b71bbb41f@linux.alibaba.com>
Date: Tue, 21 Oct 2025 21:01:38 +0800
From: Gao Xiang <hsiangkao@...ux.alibaba.com>
To: Hongbo Li <lihongbo22@...wei.com>, brauner@...nel.org
Cc: linux-erofs@...ts.ozlabs.org, linux-kernel@...r.kernel.org,
Chao Yu <chao@...nel.org>, Hongzhen Luo <hongzhen@...ux.alibaba.com>
Subject: Re: [PATCH RFC v7 5/7] erofs: support unencoded inodes for page cache
share
On 2025/10/21 18:48, Hongbo Li wrote:
> From: Hongzhen Luo <hongzhen@...ux.alibaba.com>
>
> 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% |
> +-------------------+------------------+-------------+---------------+
>
> Signed-off-by: Hongzhen Luo <hongzhen@...ux.alibaba.com>
> [hongbo: forward port, minor fixes and cleanup]
> Signed-off-by: Hongbo Li <lihongbo22@...wei.com>
> ---
> fs/erofs/data.c | 81 ++++++++++++++++++++++++++++++++++++++-----
> fs/erofs/inode.c | 5 +++
> fs/erofs/internal.h | 4 +++
> fs/erofs/ishare.c | 83 +++++++++++++++++++++++++++++++++++++++++++++
> fs/erofs/ishare.h | 18 ++++++++++
> fs/erofs/super.c | 7 ++++
> 6 files changed, 190 insertions(+), 8 deletions(-)
>
> diff --git a/fs/erofs/data.c b/fs/erofs/data.c
> index 8ca29962a3dd..438d43c959aa 100644
> --- a/fs/erofs/data.c
> +++ b/fs/erofs/data.c
> @@ -5,6 +5,7 @@
> * Copyright (C) 2021, Alibaba Cloud
> */
> #include "internal.h"
> +#include "ishare.h"
> #include <linux/sched/mm.h>
> #include <trace/events/erofs.h>
>
> @@ -266,25 +267,55 @@ void erofs_onlinefolio_end(struct folio *folio, int err, bool dirty)
> folio_end_read(folio, !(v & BIT(EROFS_ONLINEFOLIO_EIO)));
> }
>
> +struct erofs_iomap {
> + void *base;
> + struct inode *realinode;
> +};
> +
> static int erofs_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
> unsigned int flags, struct iomap *iomap, struct iomap *srcmap)
> {
> int ret;
> - struct super_block *sb = inode->i_sb;
> + struct super_block *sb;
> struct erofs_map_blocks map;
> struct erofs_map_dev mdev;
> + struct inode *realinode = inode;
> + struct erofs_iomap *erofs_iomap;
> + bool is_ishare = erofs_is_ishare_inode(inode);
> +
> + if (is_ishare) {
> + if (!iomap->private) {
I tend to pass in `iomap->private` and allocate on disk
as I mentioned in
https://lore.kernel.org/r/20250829235627.4053234-14-joannelkoong@gmail.com
to avoid unnecessary kzalloc.
Thanks,
Gao Xiang
> + erofs_iomap = kzalloc(sizeof(*erofs_iomap),
> + GFP_KERNEL);
> + if (!erofs_iomap)
> + return -ENOMEM;
> + erofs_iomap->realinode = erofs_ishare_iget(inode);
> + if (!erofs_iomap->realinode) {
> + kfree(erofs_iomap);
> + return -EINVAL;
> + }
> + iomap->private = erofs_iomap;
> + }
> + erofs_iomap = iomap->private;
> + realinode = erofs_iomap->realinode;
> + }
>
> + sb = realinode->i_sb;
> 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;
>
> iomap->offset = map.m_la;
> iomap->length = map.m_llen;
> iomap->flags = 0;
> - iomap->private = NULL;
> iomap->addr = IOMAP_NULL_ADDR;
> +
> + if (is_ishare)
> + erofs_iomap->base = NULL;
> + else
> + iomap->private = NULL;
> if (!(map.m_flags & EROFS_MAP_MAPPED)) {
> iomap->type = IOMAP_HOLE;
> return 0;
> @@ -318,7 +349,10 @@ static int erofs_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
> if (IS_ERR(ptr))
> return PTR_ERR(ptr);
> iomap->inline_data = ptr;
> - iomap->private = buf.base;
> + if (is_ishare)
> + erofs_iomap->base = buf.base;
> + else
> + iomap->private = buf.base;
> } else {
> iomap->type = IOMAP_MAPPED;
> }
> @@ -328,7 +362,17 @@ static int erofs_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
> static int erofs_iomap_end(struct inode *inode, loff_t pos, loff_t length,
> ssize_t written, unsigned int flags, struct iomap *iomap)
> {
> - void *ptr = iomap->private;
> + struct erofs_iomap *erofs_iomap;
> + bool is_ishare;
> + void *ptr;
> +
> + is_ishare = erofs_is_ishare_inode(inode);
> + if (is_ishare) {
> + erofs_iomap = iomap->private;
> + ptr = erofs_iomap->base;
> + } else {
> + ptr = iomap->private;
> + }
>
> if (ptr) {
> struct erofs_buf buf = {
> @@ -341,6 +385,12 @@ static int erofs_iomap_end(struct inode *inode, loff_t pos, loff_t length,
> } else {
> DBG_BUGON(iomap->type == IOMAP_INLINE);
> }
> +
> + if (is_ishare) {
> + erofs_ishare_iput(erofs_iomap->realinode);
> + kfree(erofs_iomap);
> + iomap->private = NULL;
> + }
> return written;
> }
>
> @@ -369,17 +419,32 @@ int erofs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
> */
> static int erofs_read_folio(struct file *file, struct folio *folio)
> {
> + struct erofs_read_ctx rdctx = {
> + .file = file,
> + .inode = folio_inode(folio),
> + };
> + int ret;
> +
> + erofs_read_begin(&rdctx);
> + ret = iomap_read_folio(folio, &erofs_iomap_ops);
> + erofs_read_end(&rdctx);
> trace_erofs_read_folio(folio, true);
>
> - return iomap_read_folio(folio, &erofs_iomap_ops);
> + return ret;
> }
>
> static void erofs_readahead(struct readahead_control *rac)
> {
> + struct erofs_read_ctx rdctx = {
> + .file = rac->file,
> + .inode = rac->mapping->host,
> + };
> +
> + erofs_read_begin(&rdctx);
> + iomap_readahead(rac, &erofs_iomap_ops);
> + erofs_read_end(&rdctx);
> trace_erofs_readahead(rac->mapping->host, readahead_index(rac),
> readahead_count(rac), true);
> -
> - return iomap_readahead(rac, &erofs_iomap_ops);
> }
>
> static sector_t erofs_bmap(struct address_space *mapping, sector_t block)
> diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c
> index cb780c095d28..fe45e6c18f8e 100644
> --- a/fs/erofs/inode.c
> +++ b/fs/erofs/inode.c
> @@ -5,6 +5,7 @@
> * Copyright (C) 2021, Alibaba Cloud
> */
> #include "xattr.h"
> +#include "ishare.h"
> #include <linux/compat.h>
> #include <trace/events/erofs.h>
>
> @@ -215,6 +216,10 @@ static int erofs_fill_inode(struct inode *inode)
> case S_IFREG:
> inode->i_op = &erofs_generic_iops;
> inode->i_fop = &erofs_file_fops;
> +#ifdef CONFIG_EROFS_FS_INODE_SHARE
> + if (erofs_ishare_fill_inode(inode))
> + inode->i_fop = &erofs_ishare_fops;
> +#endif
> break;
> case S_IFDIR:
> inode->i_op = &erofs_dir_iops;
> diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
> index 158bda6ba784..9ce6e5753978 100644
> --- a/fs/erofs/internal.h
> +++ b/fs/erofs/internal.h
> @@ -322,11 +322,15 @@ struct erofs_inode {
> spinlock_t lock;
> /* all backing inodes */
> struct list_head backing_head;
> + /* processing list */
> + struct list_head processing_head;
> };
>
> struct {
> struct inode *ishare;
> struct list_head backing_link;
> + struct list_head processing_link;
> + atomic_t processing_count;
> };
> };
> #endif
> diff --git a/fs/erofs/ishare.c b/fs/erofs/ishare.c
> index 910b732bf8e7..73432b13bf75 100644
> --- a/fs/erofs/ishare.c
> +++ b/fs/erofs/ishare.c
> @@ -72,6 +72,7 @@ static int erofs_ishare_iget5_set(struct inode *inode, void *data)
>
> vi->fingerprint = data;
> INIT_LIST_HEAD(&vi->backing_head);
> + INIT_LIST_HEAD(&vi->processing_head);
> spin_lock_init(&vi->lock);
> return 0;
> }
> @@ -124,7 +125,9 @@ bool erofs_ishare_fill_inode(struct inode *inode)
> }
>
> INIT_LIST_HEAD(&vi->backing_link);
> + INIT_LIST_HEAD(&vi->processing_link);
> vi->ishare = idedup;
> +
> spin_lock(&EROFS_I(idedup)->lock);
> list_add(&vi->backing_link, &EROFS_I(idedup)->backing_head);
> spin_unlock(&EROFS_I(idedup)->lock);
> @@ -234,3 +237,83 @@ const struct file_operations erofs_ishare_fops = {
> .get_unmapped_area = thp_get_unmapped_area,
> .splice_read = filemap_splice_read,
> };
> +
> +void erofs_read_begin(struct erofs_read_ctx *rdctx)
> +{
> + struct erofs_inode *vi, *vi_dedup;
> +
> + if (!rdctx->file || !erofs_is_ishare_inode(rdctx->inode))
> + return;
> +
> + vi = rdctx->file->private_data;
> + vi_dedup = EROFS_I(file_inode(rdctx->file));
> +
> + spin_lock(&vi_dedup->lock);
> + if (!list_empty(&vi->processing_link)) {
> + atomic_inc(&vi->processing_count);
> + } else {
> + list_add(&vi->processing_link,
> + &vi_dedup->processing_head);
> + atomic_set(&vi->processing_count, 1);
> + }
> + spin_unlock(&vi_dedup->lock);
> +}
> +
> +void erofs_read_end(struct erofs_read_ctx *rdctx)
> +{
> + struct erofs_inode *vi, *vi_dedup;
> +
> + if (!rdctx->file || !erofs_is_ishare_inode(rdctx->inode))
> + return;
> +
> + vi = rdctx->file->private_data;
> + vi_dedup = EROFS_I(file_inode(rdctx->file));
> +
> + spin_lock(&vi_dedup->lock);
> + if (atomic_dec_and_test(&vi->processing_count))
> + list_del_init(&vi->processing_link);
> + spin_unlock(&vi_dedup->lock);
> +}
> +
> +/*
> + * erofs_ishare_iget - find the backing inode.
> + */
> +struct inode *erofs_ishare_iget(struct inode *inode)
> +{
> + struct erofs_inode *vi, *vi_dedup;
> + struct inode *realinode;
> +
> + if (!erofs_is_ishare_inode(inode))
> + return igrab(inode);
> +
> + vi_dedup = EROFS_I(inode);
> + spin_lock(&vi_dedup->lock);
> + /* try processing inodes first */
> + if (!list_empty(&vi_dedup->processing_head)) {
> + list_for_each_entry(vi, &vi_dedup->processing_head,
> + processing_link) {
> + realinode = igrab(&vi->vfs_inode);
> + if (realinode) {
> + spin_unlock(&vi_dedup->lock);
> + return realinode;
> + }
> + }
> + }
> +
> + /* fall back to all backing inodes */
> + DBG_BUGON(list_empty(&vi_dedup->backing_head));
> + list_for_each_entry(vi, &vi_dedup->backing_head, backing_link) {
> + realinode = igrab(&vi->vfs_inode);
> + if (realinode)
> + break;
> + }
> + spin_unlock(&vi_dedup->lock);
> +
> + DBG_BUGON(!realinode);
> + return realinode;
> +}
> +
> +void erofs_ishare_iput(struct inode *realinode)
> +{
> + iput(realinode);
> +}
> diff --git a/fs/erofs/ishare.h b/fs/erofs/ishare.h
> index 54f2251c8179..b85fa240507b 100644
> --- a/fs/erofs/ishare.h
> +++ b/fs/erofs/ishare.h
> @@ -9,6 +9,11 @@
> #include <linux/spinlock.h>
> #include "internal.h"
>
> +struct erofs_read_ctx {
> + struct file *file; /* may be NULL */
> + struct inode *inode;
> +};
> +
> #ifdef CONFIG_EROFS_FS_INODE_SHARE
>
> int erofs_ishare_init(struct super_block *sb);
> @@ -16,6 +21,13 @@ void erofs_ishare_exit(struct super_block *sb);
> bool erofs_ishare_fill_inode(struct inode *inode);
> void erofs_ishare_free_inode(struct inode *inode);
>
> +/* read/readahead */
> +void erofs_read_begin(struct erofs_read_ctx *rdctx);
> +void erofs_read_end(struct erofs_read_ctx *rdctx);
> +
> +struct inode *erofs_ishare_iget(struct inode *inode);
> +void erofs_ishare_iput(struct inode *realinode);
> +
> #else
>
> static inline int erofs_ishare_init(struct super_block *sb) { return 0; }
> @@ -23,6 +35,12 @@ static inline void erofs_ishare_exit(struct super_block *sb) {}
> static inline bool erofs_ishare_fill_inode(struct inode *inode) { return false; }
> static inline void erofs_ishare_free_inode(struct inode *inode) {}
>
> +static inline void erofs_read_begin(struct erofs_read_ctx *rdctx) {}
> +static inline void erofs_read_end(struct erofs_read_ctx *rdctx) {}
> +
> +static inline struct inode *erofs_ishare_iget(struct inode *inode) { return inode; }
> +static inline void erofs_ishare_iput(struct inode *realinode) {}
> +
> #endif // CONFIG_EROFS_FS_INODE_SHARE
>
> #endif
> diff --git a/fs/erofs/super.c b/fs/erofs/super.c
> index f067633c0072..cba3da383558 100644
> --- a/fs/erofs/super.c
> +++ b/fs/erofs/super.c
> @@ -97,6 +97,7 @@ static void erofs_free_inode(struct inode *inode)
> erofs_free_dedup_inode(vi);
> return;
> }
> + erofs_ishare_free_inode(inode);
> if (inode->i_op == &erofs_fast_symlink_iops)
> kfree(inode->i_link);
> kfree(vi->xattr_shared_xattrs);
> @@ -762,6 +763,10 @@ static int erofs_fc_fill_super(struct super_block *sb, struct fs_context *fc)
> if (err)
> return err;
>
> + err = erofs_ishare_init(sb);
> + if (err)
> + return err;
> +
> sbi->dir_ra_bytes = EROFS_DIR_RA_BYTES;
> erofs_info(sb, "mounted with root inode @ nid %llu.", sbi->root_nid);
> return 0;
> @@ -911,6 +916,7 @@ static void erofs_kill_sb(struct super_block *sb)
> kill_anon_super(sb);
> else
> kill_block_super(sb);
> +
> erofs_drop_internal_inodes(sbi);
> fs_put_dax(sbi->dif0.dax_dev, NULL);
> erofs_fscache_unregister_fs(sb);
> @@ -922,6 +928,7 @@ static void erofs_put_super(struct super_block *sb)
> {
> struct erofs_sb_info *const sbi = EROFS_SB(sb);
>
> + erofs_ishare_exit(sb);
> erofs_unregister_sysfs(sb);
> erofs_shrinker_unregister(sb);
> erofs_xattr_prefixes_cleanup(sb);
Powered by blists - more mailing lists