From 39a8695824510a951ded696d69b8dea3c720b109 Mon Sep 17 00:00:00 2001 From: Chao Yu Date: Thu, 27 Sep 2018 18:33:18 +0800 Subject: [PATCH] f2fs: refactor ->page_mkwrite() flow Thread A Thread B - f2fs_vm_page_mkwrite - f2fs_setattr - down_write(i_mmap_sem) - truncate_setsize - f2fs_truncate - up_write(i_mmap_sem) - f2fs_reserve_block reserve NEW_ADDR - skip dirty page due to truncation 1. we don't need to rserve new block address for a truncated page. 2. dn.data_blkaddr is used out of node page lock coverage. Refactor ->page_mkwrite() flow to fix above issues: - use __do_map_lock() to avoid racing checkpoint() - lock data page in prior to dnode page - cover f2fs_reserve_block with i_mmap_sem lock - wait page writeback before zeroing page Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim --- fs/f2fs/data.c | 2 +- fs/f2fs/f2fs.h | 1 + fs/f2fs/file.c | 45 ++++++++++++++++++++++----------------------- 3 files changed, 24 insertions(+), 24 deletions(-) diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index ea16cadd416e..3f01bc2d73eb 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -972,7 +972,7 @@ int f2fs_preallocate_blocks(struct kiocb *iocb, struct iov_iter *from) return err; } -static inline void __do_map_lock(struct f2fs_sb_info *sbi, int flag, bool lock) +void __do_map_lock(struct f2fs_sb_info *sbi, int flag, bool lock) { if (flag == F2FS_GET_BLOCK_PRE_AIO) { if (lock) diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index f633662bf645..05217aad4c0b 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -3055,6 +3055,7 @@ struct page *f2fs_get_lock_data_page(struct inode *inode, pgoff_t index, struct page *f2fs_get_new_data_page(struct inode *inode, struct page *ipage, pgoff_t index, bool new_i_size); int f2fs_do_write_data_page(struct f2fs_io_info *fio); +void __do_map_lock(struct f2fs_sb_info *sbi, int flag, bool lock); int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map, int create, int flag); int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index 357422a4c319..6db808c80813 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -47,7 +47,7 @@ static vm_fault_t f2fs_vm_page_mkwrite(struct vm_fault *vmf) struct page *page = vmf->page; struct inode *inode = file_inode(vmf->vma->vm_file); struct f2fs_sb_info *sbi = F2FS_I_SB(inode); - struct dnode_of_data dn; + struct dnode_of_data dn = { .node_changed = false }; int err; if (unlikely(f2fs_cp_error(sbi))) { @@ -59,19 +59,6 @@ static vm_fault_t f2fs_vm_page_mkwrite(struct vm_fault *vmf) f2fs_bug_on(sbi, f2fs_has_inline_data(inode)); - /* block allocation */ - f2fs_lock_op(sbi); - set_new_dnode(&dn, inode, NULL, NULL, 0); - err = f2fs_reserve_block(&dn, page->index); - if (err) { - f2fs_unlock_op(sbi); - goto out; - } - f2fs_put_dnode(&dn); - f2fs_unlock_op(sbi); - - f2fs_balance_fs(sbi, dn.node_changed); - file_update_time(vmf->vma->vm_file); down_read(&F2FS_I(inode)->i_mmap_sem); lock_page(page); @@ -83,11 +70,28 @@ static vm_fault_t f2fs_vm_page_mkwrite(struct vm_fault *vmf) goto out_sem; } + /* block allocation */ + __do_map_lock(sbi, F2FS_GET_BLOCK_PRE_AIO, true); + set_new_dnode(&dn, inode, NULL, NULL, 0); + err = f2fs_get_block(&dn, page->index); + f2fs_put_dnode(&dn); + __do_map_lock(sbi, F2FS_GET_BLOCK_PRE_AIO, false); + if (err) { + unlock_page(page); + goto out_sem; + } + + /* fill the page */ + f2fs_wait_on_page_writeback(page, DATA, false); + + /* wait for GCed page writeback via META_MAPPING */ + f2fs_wait_on_block_writeback(inode, dn.data_blkaddr); + /* * check to see if the page is mapped already (no holes) */ if (PageMappedToDisk(page)) - goto mapped; + goto out_sem; /* page is wholly or partially inside EOF */ if (((loff_t)(page->index + 1) << PAGE_SHIFT) > @@ -104,16 +108,11 @@ static vm_fault_t f2fs_vm_page_mkwrite(struct vm_fault *vmf) f2fs_update_iostat(sbi, APP_MAPPED_IO, F2FS_BLKSIZE); trace_f2fs_vm_page_mkwrite(page, DATA); -mapped: - /* fill the page */ - f2fs_wait_on_page_writeback(page, DATA, false); - - /* wait for GCed page writeback via META_MAPPING */ - f2fs_wait_on_block_writeback(inode, dn.data_blkaddr); - out_sem: up_read(&F2FS_I(inode)->i_mmap_sem); -out: + + f2fs_balance_fs(sbi, dn.node_changed); + sb_end_pagefault(inode->i_sb); f2fs_update_time(sbi, REQ_TIME); err: -- GitLab