From 651fb419273300ebad459630becd839d79439bbc Mon Sep 17 00:00:00 2001
From: Qu Wenruo <wqu@suse.com>
Date: Tue, 17 Aug 2021 17:38:50 +0800
Patch-mainline: v5.16-rc1
References: jsc#SLE-17674
Git-commit: 651fb419273300ebad459630becd839d79439bbc
Subject: [PATCH 2/4] btrfs: subpage: make btrfs_alloc_subpage() return
btrfs_subpage directly
The existing calling convention of btrfs_alloc_subpage() is pretty
awful. Change it to a more common pattern by returning struct
btrfs_subpage directly and let the caller to determine if the call
succeeded.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---
fs/btrfs/extent_io.c | 6 +++---
fs/btrfs/subpage.c | 35 +++++++++++++++++++----------------
fs/btrfs/subpage.h | 5 ++---
3 files changed, 24 insertions(+), 22 deletions(-)
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 19889dbfcf15..f7895b34011e 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -6138,9 +6138,9 @@ struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
* support, so we still preallocate the memory in the loop.
*/
if (fs_info->sectorsize < PAGE_SIZE) {
- ret = btrfs_alloc_subpage(fs_info, &prealloc,
- BTRFS_SUBPAGE_METADATA);
- if (ret < 0) {
+ prealloc = btrfs_alloc_subpage(fs_info, BTRFS_SUBPAGE_METADATA);
+ if (IS_ERR(prealloc)) {
+ ret = PTR_ERR(prealloc);
unlock_page(p);
put_page(p);
exists = ERR_PTR(ret);
diff --git a/fs/btrfs/subpage.c b/fs/btrfs/subpage.c
index ff1c6ba34a4d..03dcc35d7d0b 100644
--- a/fs/btrfs/subpage.c
+++ b/fs/btrfs/subpage.c
@@ -66,8 +66,7 @@
int btrfs_attach_subpage(const struct btrfs_fs_info *fs_info,
struct page *page, enum btrfs_subpage_type type)
{
- struct btrfs_subpage *subpage = NULL;
- int ret;
+ struct btrfs_subpage *subpage;
/*
* We have cases like a dummy extent buffer page, which is not mappped
@@ -75,13 +74,15 @@ int btrfs_attach_subpage(const struct btrfs_fs_info *fs_info,
*/
if (page->mapping)
ASSERT(PageLocked(page));
+
/* Either not subpage, or the page already has private attached */
if (fs_info->sectorsize == PAGE_SIZE || PagePrivate(page))
return 0;
- ret = btrfs_alloc_subpage(fs_info, &subpage, type);
- if (ret < 0)
- return ret;
+ subpage = btrfs_alloc_subpage(fs_info, type);
+ if (IS_ERR(subpage))
+ return PTR_ERR(subpage);
+
attach_page_private(page, subpage);
return 0;
}
@@ -100,23 +101,25 @@ void btrfs_detach_subpage(const struct btrfs_fs_info *fs_info,
btrfs_free_subpage(subpage);
}
-int btrfs_alloc_subpage(const struct btrfs_fs_info *fs_info,
- struct btrfs_subpage **ret,
- enum btrfs_subpage_type type)
+struct btrfs_subpage *btrfs_alloc_subpage(const struct btrfs_fs_info *fs_info,
+ enum btrfs_subpage_type type)
{
+ struct btrfs_subpage *ret;
+
ASSERT(fs_info->sectorsize < PAGE_SIZE);
- *ret = kzalloc(sizeof(struct btrfs_subpage), GFP_NOFS);
- if (!*ret)
- return -ENOMEM;
- spin_lock_init(&(*ret)->lock);
+ ret = kzalloc(sizeof(struct btrfs_subpage), GFP_NOFS);
+ if (!ret)
+ return ERR_PTR(-ENOMEM);
+
+ spin_lock_init(&ret->lock);
if (type == BTRFS_SUBPAGE_METADATA) {
- atomic_set(&(*ret)->eb_refs, 0);
+ atomic_set(&ret->eb_refs, 0);
} else {
- atomic_set(&(*ret)->readers, 0);
- atomic_set(&(*ret)->writers, 0);
+ atomic_set(&ret->readers, 0);
+ atomic_set(&ret->writers, 0);
}
- return 0;
+ return ret;
}
void btrfs_free_subpage(struct btrfs_subpage *subpage)
diff --git a/fs/btrfs/subpage.h b/fs/btrfs/subpage.h
index 0120948f37a1..fdcadc5193c1 100644
--- a/fs/btrfs/subpage.h
+++ b/fs/btrfs/subpage.h
@@ -59,9 +59,8 @@ void btrfs_detach_subpage(const struct btrfs_fs_info *fs_info,
struct page *page);
/* Allocate additional data where page represents more than one sector */
-int btrfs_alloc_subpage(const struct btrfs_fs_info *fs_info,
- struct btrfs_subpage **ret,
- enum btrfs_subpage_type type);
+struct btrfs_subpage *btrfs_alloc_subpage(const struct btrfs_fs_info *fs_info,
+ enum btrfs_subpage_type type);
void btrfs_free_subpage(struct btrfs_subpage *subpage);
void btrfs_page_inc_eb_refs(const struct btrfs_fs_info *fs_info,
--
2.33.1