From 39e9f98dbea7676c3841c0b118d8ce981ab518b5 Mon Sep 17 00:00:00 2001 From: Sunmin Jeong Date: Wed, 10 Jul 2024 20:51:43 +0900 Subject: [PATCH] f2fs: use meta inode for GC of COW file BugLink: https://bugs.launchpad.net/bugs/2083196 commit f18d0076933689775fe7faeeb10ee93ff01be6ab upstream. In case of the COW file, new updates and GC writes are already separated to page caches of the atomic file and COW file. As some cases that use the meta inode for GC, there are some race issues between a foreground thread and GC thread. To handle them, we need to take care when to invalidate and wait writeback of GC pages in COW files as the case of using the meta inode. Also, a pointer from the COW inode to the original inode is required to check the state of original pages. For the former, we can solve the problem by using the meta inode for GC of COW files. Then let's get a page from the original inode in move_data_block when GCing the COW file to avoid race condition. Fixes: 3db1de0e582c ("f2fs: change the current atomic write way") Cc: stable@vger.kernel.org #v5.19+ Reviewed-by: Sungjong Seo Reviewed-by: Yeongjin Gil Signed-off-by: Sunmin Jeong Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Greg Kroah-Hartman Signed-off-by: Portia Stephens Signed-off-by: Roxana Nicolescu --- fs/f2fs/data.c | 2 +- fs/f2fs/f2fs.h | 13 +++++++++++-- fs/f2fs/file.c | 3 +++ fs/f2fs/gc.c | 7 +++++-- fs/f2fs/inline.c | 2 +- fs/f2fs/inode.c | 3 ++- 6 files changed, 23 insertions(+), 7 deletions(-) diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index 89806a876cb4..571eff27b776 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -2584,7 +2584,7 @@ bool f2fs_should_update_outplace(struct inode *inode, struct f2fs_io_info *fio) return true; if (IS_NOQUOTA(inode)) return true; - if (f2fs_is_atomic_file(inode)) + if (f2fs_used_in_atomic_write(inode)) return true; /* rewrite low ratio compress data w/ OPU mode to avoid fragmentation */ if (f2fs_compressed_file(inode) && diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 99c22a01675e..7ca0a7825f9b 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -843,7 +843,11 @@ struct f2fs_inode_info { struct task_struct *atomic_write_task; /* store atomic write task */ struct extent_tree *extent_tree[NR_EXTENT_CACHES]; /* cached extent_tree entry */ - struct inode *cow_inode; /* copy-on-write inode for atomic write */ + union { + struct inode *cow_inode; /* copy-on-write inode for atomic write */ + struct inode *atomic_inode; + /* point to atomic_inode, available only for cow_inode */ + }; /* avoid racing between foreground op and gc */ struct f2fs_rwsem i_gc_rwsem[2]; @@ -4265,9 +4269,14 @@ static inline bool f2fs_post_read_required(struct inode *inode) f2fs_compressed_file(inode); } +static inline bool f2fs_used_in_atomic_write(struct inode *inode) +{ + return f2fs_is_atomic_file(inode) || f2fs_is_cow_file(inode); +} + static inline bool f2fs_meta_inode_gc_required(struct inode *inode) { - return f2fs_post_read_required(inode) || f2fs_is_atomic_file(inode); + return f2fs_post_read_required(inode) || f2fs_used_in_atomic_write(inode); } /* diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index b89efa0bb403..6f20b10076bc 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -2125,6 +2125,9 @@ static int f2fs_ioc_start_atomic_write(struct file *filp, bool truncate) set_inode_flag(fi->cow_inode, FI_COW_FILE); clear_inode_flag(fi->cow_inode, FI_INLINE_DATA); + + /* Set the COW inode's atomic_inode to the atomic inode */ + F2FS_I(fi->cow_inode)->atomic_inode = inode; } else { /* Reuse the already created COW inode */ ret = f2fs_do_truncate_blocks(fi->cow_inode, 0, true); diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c index 579cac3366ed..58364a5facb6 100644 --- a/fs/f2fs/gc.c +++ b/fs/f2fs/gc.c @@ -1171,7 +1171,8 @@ static bool is_alive(struct f2fs_sb_info *sbi, struct f2fs_summary *sum, static int ra_data_block(struct inode *inode, pgoff_t index) { struct f2fs_sb_info *sbi = F2FS_I_SB(inode); - struct address_space *mapping = inode->i_mapping; + struct address_space *mapping = f2fs_is_cow_file(inode) ? + F2FS_I(inode)->atomic_inode->i_mapping : inode->i_mapping; struct dnode_of_data dn; struct page *page; struct f2fs_io_info fio = { @@ -1262,6 +1263,8 @@ put_page: static int move_data_block(struct inode *inode, block_t bidx, int gc_type, unsigned int segno, int off) { + struct address_space *mapping = f2fs_is_cow_file(inode) ? + F2FS_I(inode)->atomic_inode->i_mapping : inode->i_mapping; struct f2fs_io_info fio = { .sbi = F2FS_I_SB(inode), .ino = inode->i_ino, @@ -1284,7 +1287,7 @@ static int move_data_block(struct inode *inode, block_t bidx, CURSEG_ALL_DATA_ATGC : CURSEG_COLD_DATA; /* do not read out */ - page = f2fs_grab_cache_page(inode->i_mapping, bidx, false); + page = f2fs_grab_cache_page(mapping, bidx, false); if (!page) return -ENOMEM; diff --git a/fs/f2fs/inline.c b/fs/f2fs/inline.c index d91a818f8d18..7d4c83b131e7 100644 --- a/fs/f2fs/inline.c +++ b/fs/f2fs/inline.c @@ -16,7 +16,7 @@ static bool support_inline_data(struct inode *inode) { - if (f2fs_is_atomic_file(inode)) + if (f2fs_used_in_atomic_write(inode)) return false; if (!S_ISREG(inode->i_mode) && !S_ISLNK(inode->i_mode)) return false; diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c index 9609b02c11c2..90b89e836ecd 100644 --- a/fs/f2fs/inode.c +++ b/fs/f2fs/inode.c @@ -816,8 +816,9 @@ void f2fs_evict_inode(struct inode *inode) f2fs_abort_atomic_write(inode, true); - if (fi->cow_inode) { + if (fi->cow_inode && f2fs_is_cow_file(fi->cow_inode)) { clear_inode_flag(fi->cow_inode, FI_COW_FILE); + F2FS_I(fi->cow_inode)->atomic_inode = NULL; iput(fi->cow_inode); fi->cow_inode = NULL; }