Re: [PATCH RFC v2 2/2] erofs: apply the page cache share feature

From: Hongzhen Luo
Date: Fri Aug 02 2024 - 00:50:33 EST



On 2024/8/1 20:43, Hongbo Li wrote:


On 2024/7/31 16:07, Hongzhen Luo wrote:
This modifies relevant functions to apply the page cache
share feature.

Signed-off-by: Hongzhen Luo <hongzhen@xxxxxxxxxxxxxxxxx>
---
v2: Make adjustments based on the latest implementation.
v1: https://lore.kernel.org/all/20240722065355.1396365-5-hongzhen@xxxxxxxxxxxxxxxxx/
---
  fs/erofs/inode.c | 23 +++++++++++++++++++++++
  fs/erofs/super.c | 23 +++++++++++++++++++++++
  2 files changed, 46 insertions(+)

diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c
index 5f6439a63af7..9f1e7332cff9 100644
--- a/fs/erofs/inode.c
+++ b/fs/erofs/inode.c
@@ -5,6 +5,7 @@
   * Copyright (C) 2021, Alibaba Cloud
   */
  #include "xattr.h"
+#include "pagecache_share.h"
    #include <trace/events/erofs.h>
  @@ -229,10 +230,22 @@ 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);
+#endif
          if (erofs_inode_is_data_compressed(vi->datalayout))
              inode->i_fop = &generic_ro_fops;
+#ifdef CONFIG_EROFS_FS_PAGE_CACHE_SHARE
+        else {
If the compress data is not support, the erofs_pcs_fill_inode should fill the fingerprint in this branch only.
Sure, thanks.
+            if (vi->fprt_len > 0)
+                inode->i_fop = &erofs_pcs_file_fops;
+            else
+                inode->i_fop = &erofs_file_fops;
+        }
+#else
          else
              inode->i_fop = &erofs_file_fops;
+#endif
          break;
      case S_IFDIR:
          inode->i_op = &erofs_dir_iops;
@@ -325,6 +338,16 @@ struct inode *erofs_iget(struct super_block *sb, erofs_nid_t nid)
              return ERR_PTR(err);
          }
          unlock_new_inode(inode);
+#ifdef CONFIG_EROFS_FS_PAGE_CACHE_SHARE
+        if ((inode->i_mode & S_IFMT) == S_IFREG &&may be S_ISREG macro is better.

+            EROFS_I(inode)->fprt_len > 0) {
Perhaps this logic need to be enclosed within unlock_new_inode.
Sure, thanks.
+            err = erofs_pcs_add(inode);
+            if (err) {
+                iget_failed(inode);
+                return ERR_PTR(err);
+            }
+        }
+#endif
      }
      return inode;
  }
diff --git a/fs/erofs/super.c b/fs/erofs/super.c
index 35268263aaed..a42e65ef7fc7 100644
--- a/fs/erofs/super.c
+++ b/fs/erofs/super.c
@@ -11,6 +11,7 @@
  #include <linux/fs_parser.h>
  #include <linux/exportfs.h>
  #include "xattr.h"
+#include "pagecache_share.h"
    #define CREATE_TRACE_POINTS
  #include <trace/events/erofs.h>
@@ -95,6 +96,10 @@ static struct inode *erofs_alloc_inode(struct super_block *sb)
        /* zero out everything except vfs_inode */
      memset(vi, 0, offsetof(struct erofs_inode, vfs_inode));
+#ifdef CONFIG_EROFS_FS_PAGE_CACHE_SHARE
+    INIT_LIST_HEAD(&vi->pcs_list);
+    init_rwsem(&vi->pcs_rwsem);
+#endif
      return &vi->vfs_inode;
  }
  @@ -108,6 +113,21 @@ static void erofs_free_inode(struct inode *inode)
      kmem_cache_free(erofs_inode_cachep, vi);
  }
  +#ifdef CONFIG_EROFS_FS_PAGE_CACHE_SHARE
+static void erofs_destroy_inode(struct inode *inode)
+{
+    struct erofs_inode *vi = EROFS_I(inode);
+
+    if ((inode->i_mode & S_IFMT) == S_IFREG &&
using S_ISREG macro is better.

Thanks.

---

Hongzhen Luo

+        EROFS_I(inode)->fprt_len > 0) {
+        if (erofs_pcs_remove(inode))
+            erofs_err(inode->i_sb, "pcs: fail to remove inode.");
+        kfree(vi->fprt);
+        vi->fprt = NULL;
+    }
+}
+#endif
+
  static bool check_layout_compatibility(struct super_block *sb,
                         struct erofs_super_block *dsb)
  {
@@ -937,6 +957,9 @@ static int erofs_show_options(struct seq_file *seq, struct dentry *root)
  const struct super_operations erofs_sops = {
      .put_super = erofs_put_super,
      .alloc_inode = erofs_alloc_inode,
+#ifdef CONFIG_EROFS_FS_PAGE_CACHE_SHARE
+    .destroy_inode = erofs_destroy_inode,
+#endif
      .free_inode = erofs_free_inode,
      .statfs = erofs_statfs,
      .show_options = erofs_show_options,