From fdf250db89b65167891a73327f8cd4f58a323612 Mon Sep 17 00:00:00 2001
From: Qu Wenruo <wqu@suse.com>
Date: Tue, 17 Aug 2021 17:38:49 +0800
Patch-mainline: v5.16-rc1
References: jsc#SLE-17674
Git-commit: fdf250db89b65167891a73327f8cd4f58a323612
Subject: [PATCH 1/4] btrfs: subpage: only call btrfs_alloc_subpage() when
sectorsize is smaller than PAGE_SIZE
There are two call sites of btrfs_alloc_subpage():
- btrfs_attach_subpage()
We have ensured sectorsize is smaller than PAGE_SIZE
- alloc_extent_buffer()
We call btrfs_alloc_subpage() unconditionally.
The alloc_extent_buffer() forces us to check the sectorsize size against
page size inside btrfs_alloc_subpage().
Since the function name, btrfs_alloc_subpage(), already indicates it
should only get called for subpage cases, do the check in
alloc_extent_buffer() and add an ASSERT() in btrfs_alloc_subpage().
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 | 16 +++++++++-------
fs/btrfs/subpage.c | 3 +--
2 files changed, 10 insertions(+), 9 deletions(-)
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index aaddd7225348..19889dbfcf15 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -6137,13 +6137,15 @@ struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
* page, but it may change in the future for 16K page size
* support, so we still preallocate the memory in the loop.
*/
- ret = btrfs_alloc_subpage(fs_info, &prealloc,
- BTRFS_SUBPAGE_METADATA);
- if (ret < 0) {
- unlock_page(p);
- put_page(p);
- exists = ERR_PTR(ret);
- goto free_eb;
+ if (fs_info->sectorsize < PAGE_SIZE) {
+ ret = btrfs_alloc_subpage(fs_info, &prealloc,
+ BTRFS_SUBPAGE_METADATA);
+ if (ret < 0) {
+ unlock_page(p);
+ put_page(p);
+ exists = ERR_PTR(ret);
+ goto free_eb;
+ }
}
spin_lock(&mapping->private_lock);
diff --git a/fs/btrfs/subpage.c b/fs/btrfs/subpage.c
index cb10e56ee31e..ff1c6ba34a4d 100644
--- a/fs/btrfs/subpage.c
+++ b/fs/btrfs/subpage.c
@@ -104,8 +104,7 @@ int btrfs_alloc_subpage(const struct btrfs_fs_info *fs_info,
struct btrfs_subpage **ret,
enum btrfs_subpage_type type)
{
- if (fs_info->sectorsize == PAGE_SIZE)
- return 0;
+ ASSERT(fs_info->sectorsize < PAGE_SIZE);
*ret = kzalloc(sizeof(struct btrfs_subpage), GFP_NOFS);
if (!*ret)
--
2.33.1