[PATCH 5.0 90/93] f2fs: fix to add refcount once page is tagged PG_private
From: Greg Kroah-Hartman
Date: Thu Apr 18 2019 - 14:13:10 EST
[ Upstream commit 240a59156d9bcfabceddb66be449e7b32fb5dc4a ]
As Gao Xiang reported in bugzilla:
https://bugzilla.kernel.org/show_bug.cgi?id=202749
f2fs may skip pageout() due to incorrect page reference count.
The problem here is that MM defined the rule [1] very clearly that
once page was set with PG_private flag, we should increment the
refcount in that page, also main flows like pageout(), migrate_page()
will assume there is one additional page reference count if
page_has_private() returns true.
But currently, f2fs won't add/del refcount when changing PG_private
flag. Anyway, f2fs should follow MM's rule to make MM's related flows
running as expected.
[1] https://lore.kernel.org/lkml/2b19b3c4-2bc4-15fa-15cc-27a13e5c7af1@xxxxxxx/
Reported-by: Gao Xiang <gaoxiang25@xxxxxxxxxx>
Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx>
Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
fs/f2fs/checkpoint.c | 4 ++--
fs/f2fs/data.c | 21 ++++++++-------------
fs/f2fs/dir.c | 2 +-
fs/f2fs/f2fs.h | 21 +++++++++++++++++++++
fs/f2fs/node.c | 2 +-
fs/f2fs/segment.c | 9 +++------
6 files changed, 36 insertions(+), 23 deletions(-)
diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index ccccf0ce2f06..7743fa83b895 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -406,7 +406,7 @@ static int f2fs_set_meta_page_dirty(struct page *page)
if (!PageDirty(page)) {
__set_page_dirty_nobuffers(page);
inc_page_count(F2FS_P_SB(page), F2FS_DIRTY_META);
- SetPagePrivate(page);
+ f2fs_set_page_private(page, 0);
f2fs_trace_pid(page);
return 1;
}
@@ -957,7 +957,7 @@ void f2fs_update_dirty_page(struct inode *inode, struct page *page)
inode_inc_dirty_pages(inode);
spin_unlock(&sbi->inode_lock[type]);
- SetPagePrivate(page);
+ f2fs_set_page_private(page, 0);
f2fs_trace_pid(page);
}
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index f91d8630c9a2..c99aab23efea 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -2711,8 +2711,7 @@ void f2fs_invalidate_page(struct page *page, unsigned int offset,
if (IS_ATOMIC_WRITTEN_PAGE(page))
return f2fs_drop_inmem_page(inode, page);
- set_page_private(page, 0);
- ClearPagePrivate(page);
+ f2fs_clear_page_private(page);
}
int f2fs_release_page(struct page *page, gfp_t wait)
@@ -2726,8 +2725,7 @@ int f2fs_release_page(struct page *page, gfp_t wait)
return 0;
clear_cold_data(page);
- set_page_private(page, 0);
- ClearPagePrivate(page);
+ f2fs_clear_page_private(page);
return 1;
}
@@ -2795,12 +2793,8 @@ int f2fs_migrate_page(struct address_space *mapping,
return -EAGAIN;
}
- /*
- * A reference is expected if PagePrivate set when move mapping,
- * however F2FS breaks this for maintaining dirty page counts when
- * truncating pages. So here adjusting the 'extra_count' make it work.
- */
- extra_count = (atomic_written ? 1 : 0) - page_has_private(page);
+ /* one extra reference was held for atomic_write page */
+ extra_count = atomic_written ? 1 : 0;
rc = migrate_page_move_mapping(mapping, newpage,
page, mode, extra_count);
if (rc != MIGRATEPAGE_SUCCESS) {
@@ -2821,9 +2815,10 @@ int f2fs_migrate_page(struct address_space *mapping,
get_page(newpage);
}
- if (PagePrivate(page))
- SetPagePrivate(newpage);
- set_page_private(newpage, page_private(page));
+ if (PagePrivate(page)) {
+ f2fs_set_page_private(newpage, page_private(page));
+ f2fs_clear_page_private(page);
+ }
if (mode != MIGRATE_SYNC_NO_COPY)
migrate_page_copy(newpage, page);
diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c
index 50d0d36280fa..99a6063c2327 100644
--- a/fs/f2fs/dir.c
+++ b/fs/f2fs/dir.c
@@ -728,7 +728,7 @@ void f2fs_delete_entry(struct f2fs_dir_entry *dentry, struct page *page,
!f2fs_truncate_hole(dir, page->index, page->index + 1)) {
f2fs_clear_page_cache_dirty_tag(page);
clear_page_dirty_for_io(page);
- ClearPagePrivate(page);
+ f2fs_clear_page_private(page);
ClearPageUptodate(page);
clear_cold_data(page);
inode_dec_dirty_pages(dir);
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 279bc00489cc..6d9186a6528c 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -2825,6 +2825,27 @@ static inline bool is_valid_data_blkaddr(struct f2fs_sb_info *sbi,
return true;
}
+static inline void f2fs_set_page_private(struct page *page,
+ unsigned long data)
+{
+ if (PagePrivate(page))
+ return;
+
+ get_page(page);
+ SetPagePrivate(page);
+ set_page_private(page, data);
+}
+
+static inline void f2fs_clear_page_private(struct page *page)
+{
+ if (!PagePrivate(page))
+ return;
+
+ set_page_private(page, 0);
+ ClearPagePrivate(page);
+ f2fs_put_page(page, 0);
+}
+
/*
* file.c
*/
diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index f6ff84e29749..3f99ab288695 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -1961,7 +1961,7 @@ static int f2fs_set_node_page_dirty(struct page *page)
if (!PageDirty(page)) {
__set_page_dirty_nobuffers(page);
inc_page_count(F2FS_P_SB(page), F2FS_DIRTY_NODES);
- SetPagePrivate(page);
+ f2fs_set_page_private(page, 0);
f2fs_trace_pid(page);
return 1;
}
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index e1b1d390b329..b6c8b0696ef6 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -191,8 +191,7 @@ void f2fs_register_inmem_page(struct inode *inode, struct page *page)
f2fs_trace_pid(page);
- set_page_private(page, (unsigned long)ATOMIC_WRITTEN_PAGE);
- SetPagePrivate(page);
+ f2fs_set_page_private(page, (unsigned long)ATOMIC_WRITTEN_PAGE);
new = f2fs_kmem_cache_alloc(inmem_entry_slab, GFP_NOFS);
@@ -280,8 +279,7 @@ static int __revoke_inmem_pages(struct inode *inode,
ClearPageUptodate(page);
clear_cold_data(page);
}
- set_page_private(page, 0);
- ClearPagePrivate(page);
+ f2fs_clear_page_private(page);
f2fs_put_page(page, 1);
list_del(&cur->list);
@@ -370,8 +368,7 @@ void f2fs_drop_inmem_page(struct inode *inode, struct page *page)
kmem_cache_free(inmem_entry_slab, cur);
ClearPageUptodate(page);
- set_page_private(page, 0);
- ClearPagePrivate(page);
+ f2fs_clear_page_private(page);
f2fs_put_page(page, 0);
trace_f2fs_commit_inmem_page(page, INMEM_INVALIDATE);
--
2.19.1