From 8d2e73e21dd5c232f7e59c3e0b3c6ea5b800e273 Mon Sep 17 00:00:00 2001 From: Chao Yu Date: Tue, 25 Jun 2024 11:13:48 +0800 Subject: [PATCH] f2fs: atomic: fix to avoid racing w/ GC [ Upstream commit 1a0bd289a5db1df8df8fab949633a0b8d3f235ee ] Case #1: SQLite App GC Thread Kworker Shrinker - f2fs_ioc_start_atomic_write - f2fs_ioc_commit_atomic_write - f2fs_commit_atomic_write - filemap_write_and_wait_range : write atomic_file's data to cow_inode echo 3 > drop_caches to drop atomic_file's cache. - f2fs_gc - gc_data_segment - move_data_page - set_page_dirty - writepages - f2fs_do_write_data_page : overwrite atomic_file's data to cow_inode - f2fs_down_write(&fi->i_gc_rwsem[WRITE]) - __f2fs_commit_atomic_write - f2fs_up_write(&fi->i_gc_rwsem[WRITE]) Case #2: SQLite App GC Thread Kworker - f2fs_ioc_start_atomic_write - __writeback_single_inode - do_writepages - f2fs_write_cache_pages - f2fs_write_single_data_page - f2fs_do_write_data_page : write atomic_file's data to cow_inode - f2fs_gc - gc_data_segment - move_data_page - set_page_dirty - writepages - f2fs_do_write_data_page : overwrite atomic_file's data to cow_inode - f2fs_ioc_commit_atomic_write In above cases racing in between atomic_write and GC, previous data in atomic_file may be overwrited to cow_file, result in data corruption. This patch introduces PAGE_PRIVATE_ATOMIC_WRITE bit flag in page.private, and use it to indicate that there is last dirty data in atomic file, and the data should be writebacked into cow_file, if the flag is not tagged in page, we should never write data across files. Fixes: 3db1de0e582c ("f2fs: change the current atomic write way") Cc: Daeho Jeong Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Sasha Levin --- fs/f2fs/data.c | 10 +++++++++- fs/f2fs/f2fs.h | 8 +++++++- 2 files changed, 16 insertions(+), 2 deletions(-) diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index 6457e5bca9c9..be66b3a0e793 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -2650,10 +2650,13 @@ int f2fs_do_write_data_page(struct f2fs_io_info *fio) struct dnode_of_data dn; struct node_info ni; bool ipu_force = false; + bool atomic_commit; int err = 0; /* Use COW inode to make dnode_of_data for atomic write */ - if (f2fs_is_atomic_file(inode)) + atomic_commit = f2fs_is_atomic_file(inode) && + page_private_atomic(fio->page); + if (atomic_commit) set_new_dnode(&dn, F2FS_I(inode)->cow_inode, NULL, NULL, 0); else set_new_dnode(&dn, inode, NULL, NULL, 0); @@ -2752,6 +2755,8 @@ int f2fs_do_write_data_page(struct f2fs_io_info *fio) f2fs_outplace_write_data(&dn, fio); trace_f2fs_do_write_data_page(page_folio(page), OPU); set_inode_flag(inode, FI_APPEND_WRITE); + if (atomic_commit) + clear_page_private_atomic(page); out_writepage: f2fs_put_dnode(&dn); out: @@ -3721,6 +3726,9 @@ static int f2fs_write_end(struct file *file, set_page_dirty(page); + if (f2fs_is_atomic_file(inode)) + set_page_private_atomic(page); + if (pos + copied > i_size_read(inode) && !f2fs_verity_in_progress(inode)) { f2fs_i_size_write(inode, pos + copied); diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index ac19c61f0c3e..9f8dd17b85b9 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -1418,7 +1418,8 @@ static inline void f2fs_clear_bit(unsigned int nr, char *addr); * bit 1 PAGE_PRIVATE_ONGOING_MIGRATION * bit 2 PAGE_PRIVATE_INLINE_INODE * bit 3 PAGE_PRIVATE_REF_RESOURCE - * bit 4- f2fs private data + * bit 4 PAGE_PRIVATE_ATOMIC_WRITE + * bit 5- f2fs private data * * Layout B: lowest bit should be 0 * page.private is a wrapped pointer. @@ -1428,6 +1429,7 @@ enum { PAGE_PRIVATE_ONGOING_MIGRATION, /* data page which is on-going migrating */ PAGE_PRIVATE_INLINE_INODE, /* inode page contains inline data */ PAGE_PRIVATE_REF_RESOURCE, /* dirty page has referenced resources */ + PAGE_PRIVATE_ATOMIC_WRITE, /* data page from atomic write path */ PAGE_PRIVATE_MAX }; @@ -2396,14 +2398,17 @@ static inline void clear_page_private_##name(struct page *page) \ PAGE_PRIVATE_GET_FUNC(nonpointer, NOT_POINTER); PAGE_PRIVATE_GET_FUNC(inline, INLINE_INODE); PAGE_PRIVATE_GET_FUNC(gcing, ONGOING_MIGRATION); +PAGE_PRIVATE_GET_FUNC(atomic, ATOMIC_WRITE); PAGE_PRIVATE_SET_FUNC(reference, REF_RESOURCE); PAGE_PRIVATE_SET_FUNC(inline, INLINE_INODE); PAGE_PRIVATE_SET_FUNC(gcing, ONGOING_MIGRATION); +PAGE_PRIVATE_SET_FUNC(atomic, ATOMIC_WRITE); PAGE_PRIVATE_CLEAR_FUNC(reference, REF_RESOURCE); PAGE_PRIVATE_CLEAR_FUNC(inline, INLINE_INODE); PAGE_PRIVATE_CLEAR_FUNC(gcing, ONGOING_MIGRATION); +PAGE_PRIVATE_CLEAR_FUNC(atomic, ATOMIC_WRITE); static inline unsigned long get_page_private_data(struct page *page) { @@ -2435,6 +2440,7 @@ static inline void clear_page_private_all(struct page *page) clear_page_private_reference(page); clear_page_private_gcing(page); clear_page_private_inline(page); + clear_page_private_atomic(page); f2fs_bug_on(F2FS_P_SB(page), page_private(page)); }