On 04/20, Chao Yu wrote: > On 2018/4/20 11:12, Jaegeuk Kim wrote: > > On 04/18, Chao Yu wrote: > >> f2fs doesn't allow abuse on atomic write class interface, so except > >> limiting in-mem pages' total memory usage capacity, we need to limit > >> atomic-write usage as well when filesystem is seriously fragmented, > >> otherwise we may run into infinite loop during foreground GC because > >> target blocks in victim segment are belong to atomic opened file for > >> long time. > >> > >> Now, we will detect failure due to atomic write in foreground GC, if > >> the count exceeds threshold, we will drop all atomic written data in > >> cache, by this, I expect it can keep our system running safely to > >> prevent Dos attack. > >> > >> Signed-off-by: Chao Yu <yuch...@huawei.com> > >> --- > >> fs/f2fs/f2fs.h | 1 + > >> fs/f2fs/file.c | 5 +++++ > >> fs/f2fs/gc.c | 27 +++++++++++++++++++++++---- > >> fs/f2fs/gc.h | 3 +++ > >> fs/f2fs/segment.c | 1 + > >> fs/f2fs/segment.h | 2 ++ > >> 6 files changed, 35 insertions(+), 4 deletions(-) > >> > >> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h > >> index c1c3a1d11186..3453288d6a71 100644 > >> --- a/fs/f2fs/f2fs.h > >> +++ b/fs/f2fs/f2fs.h > >> @@ -2249,6 +2249,7 @@ enum { > >> FI_EXTRA_ATTR, /* indicate file has extra attribute */ > >> FI_PROJ_INHERIT, /* indicate file inherits projectid */ > >> FI_PIN_FILE, /* indicate file should not be gced */ > >> + FI_ATOMIC_REVOKE_REQUEST,/* indicate atomic committed data has been > >> dropped */ > >> }; > >> > >> static inline void __mark_inode_dirty_flag(struct inode *inode, > >> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c > >> index 7c90ded5a431..cddd9aee1bb2 100644 > >> --- a/fs/f2fs/file.c > >> +++ b/fs/f2fs/file.c > >> @@ -1698,6 +1698,7 @@ static int f2fs_ioc_start_atomic_write(struct file > >> *filp) > >> skip_flush: > >> set_inode_flag(inode, FI_HOT_DATA); > >> set_inode_flag(inode, FI_ATOMIC_FILE); > >> + clear_inode_flag(inode, FI_ATOMIC_REVOKE_REQUEST); > >> f2fs_update_time(F2FS_I_SB(inode), REQ_TIME); > >> > >> F2FS_I(inode)->inmem_task = current; > >> @@ -1746,6 +1747,10 @@ static int f2fs_ioc_commit_atomic_write(struct file > >> *filp) > >> ret = f2fs_do_sync_file(filp, 0, LLONG_MAX, 1, false); > >> } > >> err_out: > >> + if (is_inode_flag_set(inode, FI_ATOMIC_REVOKE_REQUEST)) { > >> + clear_inode_flag(inode, FI_ATOMIC_REVOKE_REQUEST); > >> + ret = -EINVAL; > >> + } > >> up_write(&F2FS_I(inode)->dio_rwsem[WRITE]); > >> inode_unlock(inode); > >> mnt_drop_write_file(filp); > >> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c > >> index bfb7a4a3a929..495876ca62b6 100644 > >> --- a/fs/f2fs/gc.c > >> +++ b/fs/f2fs/gc.c > >> @@ -135,6 +135,8 @@ int start_gc_thread(struct f2fs_sb_info *sbi) > >> gc_th->gc_urgent = 0; > >> gc_th->gc_wake= 0; > >> > >> + gc_th->atomic_file = 0; > >> + > >> sbi->gc_thread = gc_th; > >> init_waitqueue_head(&sbi->gc_thread->gc_wait_queue_head); > >> sbi->gc_thread->f2fs_gc_task = kthread_run(gc_thread_func, sbi, > >> @@ -603,7 +605,7 @@ static bool is_alive(struct f2fs_sb_info *sbi, struct > >> f2fs_summary *sum, > >> * This can be used to move blocks, aka LBAs, directly on disk. > >> */ > >> static void move_data_block(struct inode *inode, block_t bidx, > >> - unsigned int segno, int off) > >> + int gc_type, unsigned int segno, int off) > >> { > >> struct f2fs_io_info fio = { > >> .sbi = F2FS_I_SB(inode), > >> @@ -630,8 +632,10 @@ static void move_data_block(struct inode *inode, > >> block_t bidx, > >> if (!check_valid_map(F2FS_I_SB(inode), segno, off)) > >> goto out; > >> > >> - if (f2fs_is_atomic_file(inode)) > >> + if (f2fs_is_atomic_file(inode)) { > >> + F2FS_I_SB(inode)->gc_thread->atomic_file++; > >> goto out; > >> + } > >> > >> if (f2fs_is_pinned_file(inode)) { > >> f2fs_pin_file_control(inode, true); > >> @@ -737,8 +741,10 @@ static void move_data_page(struct inode *inode, > >> block_t bidx, int gc_type, > >> if (!check_valid_map(F2FS_I_SB(inode), segno, off)) > >> goto out; > >> > >> - if (f2fs_is_atomic_file(inode)) > >> + if (f2fs_is_atomic_file(inode)) { > >> + F2FS_I_SB(inode)->gc_thread->atomic_file++; > >> goto out; > >> + } > >> if (f2fs_is_pinned_file(inode)) { > >> if (gc_type == FG_GC) > >> f2fs_pin_file_control(inode, true); > >> @@ -900,7 +906,8 @@ static void gc_data_segment(struct f2fs_sb_info *sbi, > >> struct f2fs_summary *sum, > >> start_bidx = start_bidx_of_node(nofs, inode) > >> + ofs_in_node; > >> if (f2fs_encrypted_file(inode)) > >> - move_data_block(inode, start_bidx, segno, off); > >> + move_data_block(inode, start_bidx, gc_type, > >> + segno, off); > >> else > >> move_data_page(inode, start_bidx, gc_type, > >> segno, off); > >> @@ -1017,6 +1024,8 @@ int f2fs_gc(struct f2fs_sb_info *sbi, bool sync, > >> .ilist = LIST_HEAD_INIT(gc_list.ilist), > >> .iroot = RADIX_TREE_INIT(GFP_NOFS), > >> }; > >> + unsigned int last_atomic_file = sbi->gc_thread->atomic_file; > >> + unsigned int skipped_round = 0, round = 0; > >> > >> trace_f2fs_gc_begin(sbi->sb, sync, background, > >> get_pages(sbi, F2FS_DIRTY_NODES), > >> @@ -1068,11 +1077,21 @@ int f2fs_gc(struct f2fs_sb_info *sbi, bool sync, > >> sec_freed++; > >> total_freed += seg_freed; > >> > >> + if (gc_type == FG_GC) { > >> + if (sbi->gc_thread->atomic_file > last_atomic_file) > >> + skipped_round++; > >> + last_atomic_file = sbi->gc_thread->atomic_file; > > > > How about resetting ->atomic_file to zero? > > Since we will show this stat number through sysfs entry, it'd better to keep > its > data?
Alright, but we need to manage overflow? > > Thanks, > > > > >> + round++; > >> + } > >> + > >> if (gc_type == FG_GC) > >> sbi->cur_victim_sec = NULL_SEGNO; > >> > >> if (!sync) { > >> if (has_not_enough_free_secs(sbi, sec_freed, 0)) { > >> + if (skipped_round > MAX_SKIP_ATOMIC_COUNT && > >> + skipped_round * 2 >= round) > >> + drop_inmem_pages_all(sbi); > >> segno = NULL_SEGNO; > >> goto gc_more; > >> } > >> diff --git a/fs/f2fs/gc.h b/fs/f2fs/gc.h > >> index b0045d4c8d1e..bc1d21d46ae7 100644 > >> --- a/fs/f2fs/gc.h > >> +++ b/fs/f2fs/gc.h > >> @@ -39,6 +39,9 @@ struct f2fs_gc_kthread { > >> unsigned int gc_idle; > >> unsigned int gc_urgent; > >> unsigned int gc_wake; > >> + > >> + /* for stuck statistic */ > >> + unsigned int atomic_file; > >> }; > >> > >> struct gc_inode_list { > >> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c > >> index d809f731bfd1..831cefa088bc 100644 > >> --- a/fs/f2fs/segment.c > >> +++ b/fs/f2fs/segment.c > >> @@ -287,6 +287,7 @@ void drop_inmem_pages_all(struct f2fs_sb_info *sbi) > >> spin_unlock(&sbi->inode_lock[ATOMIC_FILE]); > >> > >> if (inode) { > >> + set_inode_flag(inode, FI_ATOMIC_REVOKE_REQUEST); > >> drop_inmem_pages(inode); > >> iput(inode); > >> } > >> diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h > >> index 492ad0c86fa9..7702b054689c 100644 > >> --- a/fs/f2fs/segment.h > >> +++ b/fs/f2fs/segment.h > >> @@ -215,6 +215,8 @@ struct segment_allocation { > >> #define IS_DUMMY_WRITTEN_PAGE(page) \ > >> (page_private(page) == (unsigned long)DUMMY_WRITTEN_PAGE) > >> > >> +#define MAX_SKIP_ATOMIC_COUNT 16 > >> + > >> struct inmem_pages { > >> struct list_head list; > >> struct page *page; > >> -- > >> 2.15.0.55.gc2ece9dc4de6 > > > > . > > ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel