[PATCH RFC 3/4] erofs: apply the page cache share feature
Christian Brauner
brauner at kernel.org
Thu Jul 3 22:23:12 AEST 2025
From: Hongzhen Luo <hongzhen at linux.alibaba.com>
This modifies relevant functions to apply the page cache
share feature.
Signed-off-by: Hongzhen Luo <hongzhen at linux.alibaba.com>
Link: https://lore.kernel.org/20240902110620.2202586-4-hongzhen@linux.alibaba.com
Signed-off-by: Christian Brauner <brauner at kernel.org>
---
fs/erofs/data.c | 33 +++++++++++++++++++++++++++++++++
fs/erofs/inode.c | 15 ++++++++++++++-
fs/erofs/super.c | 29 +++++++++++++++++++++++++++++
fs/erofs/zdata.c | 32 ++++++++++++++++++++++++++++++++
4 files changed, 108 insertions(+), 1 deletion(-)
diff --git a/fs/erofs/data.c b/fs/erofs/data.c
index 6a329c329f43..fb54162f4c54 100644
--- a/fs/erofs/data.c
+++ b/fs/erofs/data.c
@@ -351,12 +351,45 @@ int erofs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
*/
static int erofs_read_folio(struct file *file, struct folio *folio)
{
+#ifdef CONFIG_EROFS_FS_PAGE_CACHE_SHARE
+ struct erofs_inode *vi = NULL;
+ int ret;
+
+ if (file && file->private_data) {
+ vi = file->private_data;
+ if (vi->ano_inode == file_inode(file))
+ folio->mapping->host = &vi->vfs_inode;
+ else
+ vi = NULL;
+ }
+ ret = iomap_read_folio(folio, &erofs_iomap_ops);
+ if (vi)
+ folio->mapping->host = file_inode(file);
+ return ret;
+#else
return iomap_read_folio(folio, &erofs_iomap_ops);
+#endif
}
static void erofs_readahead(struct readahead_control *rac)
{
+#ifdef CONFIG_EROFS_FS_PAGE_CACHE_SHARE
+ struct erofs_inode *vi = NULL;
+ struct file *file = rac->file;
+
+ if (file && file->private_data) {
+ vi = file->private_data;
+ if (vi->ano_inode == file_inode(file))
+ rac->mapping->host = &vi->vfs_inode;
+ else
+ vi = NULL;
+ }
+ iomap_readahead(rac, &erofs_iomap_ops);
+ if (vi)
+ rac->mapping->host = file_inode(file);
+#else
return iomap_readahead(rac, &erofs_iomap_ops);
+#endif
}
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 a0ae0b4f7b01..57a23bd9d196 100644
--- a/fs/erofs/inode.c
+++ b/fs/erofs/inode.c
@@ -4,9 +4,11 @@
* https://www.huawei.com/
* Copyright (C) 2021, Alibaba Cloud
*/
-#include "xattr.h"
#include <trace/events/erofs.h>
+#include "xattr.h"
+#include "pagecache_share.h"
+
static int erofs_fill_symlink(struct inode *inode, void *kaddr,
unsigned int m_pofs)
{
@@ -212,10 +214,21 @@ static int erofs_fill_inode(struct inode *inode)
switch (inode->i_mode & S_IFMT) {
case S_IFREG:
inode->i_op = &erofs_generic_iops;
+#ifdef CONFIG_EROFS_FS_PAGE_CACHE_SHARE
+ erofs_pcs_fill_inode(inode);
+ if (vi->ano_inode)
+ inode->i_fop = &erofs_pcs_file_fops;
+ else if (erofs_inode_is_data_compressed(vi->datalayout))
+ inode->i_fop = &generic_ro_fops;
+ else
+ inode->i_fop = &erofs_file_fops;
+#else
if (erofs_inode_is_data_compressed(vi->datalayout))
inode->i_fop = &generic_ro_fops;
else
inode->i_fop = &erofs_file_fops;
+#endif
+
break;
case S_IFDIR:
inode->i_op = &erofs_dir_iops;
diff --git a/fs/erofs/super.c b/fs/erofs/super.c
index 8fb14df2a343..b9a71840cc45 100644
--- a/fs/erofs/super.c
+++ b/fs/erofs/super.c
@@ -13,6 +13,7 @@
#include <linux/backing-dev.h>
#include <linux/pseudo_fs.h>
#include "xattr.h"
+#include "pagecache_share.h"
#define CREATE_TRACE_POINTS
#include <trace/events/erofs.h>
@@ -81,6 +82,12 @@ static void erofs_free_inode(struct inode *inode)
{
struct erofs_inode *vi = EROFS_I(inode);
+#ifdef CONFIG_EROFS_FS_PAGE_CACHE_SHARE
+ if (S_ISREG(inode->i_mode) && vi->ano_inode) {
+ iput(vi->ano_inode);
+ vi->ano_inode = NULL;
+ }
+#endif
if (inode->i_op == &erofs_fast_symlink_iops)
kfree(inode->i_link);
kfree(vi->xattr_shared_xattrs);
@@ -716,6 +723,12 @@ static int erofs_fc_fill_super(struct super_block *sb, struct fs_context *fc)
if (err)
return err;
+#ifdef CONFIG_EROFS_FS_PAGE_CACHE_SHARE
+ err = erofs_pcs_init_mnt();
+ if (err)
+ return err;
+#endif
+
erofs_info(sb, "mounted with root inode @ nid %llu.", sbi->root_nid);
return 0;
}
@@ -863,6 +876,9 @@ static void erofs_kill_sb(struct super_block *sb)
kill_block_super(sb);
erofs_drop_internal_inodes(sbi);
fs_put_dax(sbi->dif0.dax_dev, NULL);
+#ifdef CONFIG_EROFS_FS_PAGE_CACHE_SHARE
+ erofs_pcs_free_mnt();
+#endif
erofs_fscache_unregister_fs(sb);
erofs_sb_free(sbi);
sb->s_fs_info = NULL;
@@ -890,8 +906,21 @@ static struct file_system_type erofs_fs_type = {
};
MODULE_ALIAS_FS("erofs");
+#ifdef CONFIG_EROFS_FS_PAGE_CACHE_SHARE
+static void erofs_free_anon_inode(struct inode *inode)
+{
+ if (inode->i_private) {
+ kfree(inode->i_private);
+ inode->i_private = NULL;
+ }
+}
+#endif
+
static const struct super_operations erofs_anon_sops = {
.statfs = simple_statfs,
+#ifdef CONFIG_EROFS_FS_PAGE_CACHE_SHARE
+ .free_inode = erofs_free_anon_inode,
+#endif
};
static int erofs_anon_init_fs_context(struct fs_context *fc)
diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
index fe8071844724..346d34aa6a6c 100644
--- a/fs/erofs/zdata.c
+++ b/fs/erofs/zdata.c
@@ -1862,6 +1862,17 @@ static void z_erofs_pcluster_readmore(struct z_erofs_frontend *f,
static int z_erofs_read_folio(struct file *file, struct folio *folio)
{
+#ifdef CONFIG_EROFS_FS_PAGE_CACHE_SHARE
+ struct erofs_inode *vi = NULL;
+
+ if (file && file->private_data) {
+ vi = file->private_data;
+ if (vi->ano_inode == file_inode(file))
+ folio->mapping->host = &vi->vfs_inode;
+ else
+ vi = NULL;
+ }
+#endif
struct inode *const inode = folio->mapping->host;
Z_EROFS_DEFINE_FRONTEND(f, inode, folio_pos(folio));
int err;
@@ -1880,11 +1891,27 @@ static int z_erofs_read_folio(struct file *file, struct folio *folio)
erofs_put_metabuf(&f.map.buf);
erofs_release_pages(&f.pagepool);
+
+#ifdef CONFIG_EROFS_FS_PAGE_CACHE_SHARE
+ if (vi)
+ folio->mapping->host = file_inode(file);
+#endif
return err;
}
static void z_erofs_readahead(struct readahead_control *rac)
{
+#ifdef CONFIG_EROFS_FS_PAGE_CACHE_SHARE
+ struct erofs_inode *vi = NULL;
+
+ if (rac->file && rac->file->private_data) {
+ vi = rac->file->private_data;
+ if (vi->ano_inode == file_inode(rac->file))
+ rac->mapping->host = &vi->vfs_inode;
+ else
+ vi = NULL;
+ }
+#endif
struct inode *const inode = rac->mapping->host;
Z_EROFS_DEFINE_FRONTEND(f, inode, readahead_pos(rac));
unsigned int nrpages = readahead_count(rac);
@@ -1914,6 +1941,11 @@ static void z_erofs_readahead(struct readahead_control *rac)
(void)z_erofs_runqueue(&f, nrpages);
erofs_put_metabuf(&f.map.buf);
erofs_release_pages(&f.pagepool);
+
+#ifdef CONFIG_EROFS_FS_PAGE_CACHE_SHARE
+ if (vi)
+ rac->mapping->host = file_inode(rac->file);
+#endif
}
const struct address_space_operations z_erofs_aops = {
--
2.47.2
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