From: Ryusuke Konishi <konishi.ryusuke@xxxxxxxxx> Subject: nilfs2: fix lockdep warnings during disk space reclamation During disk space reclamation, nilfs2 still emits the following lockdep warning due to page/folio operations on shadowed page caches that nilfs2 uses to get a snapshot of DAT file in memory: WARNING: CPU: 0 PID: 2643 at include/linux/backing-dev.h:272 __folio_mark_dirty+0x645/0x670 ... RIP: 0010:__folio_mark_dirty+0x645/0x670 ... Call Trace: <TASK> filemap_dirty_folio+0x74/0xd0 __set_page_dirty_nobuffers+0x85/0xb0 nilfs_copy_dirty_pages+0x288/0x510 [nilfs2] nilfs_mdt_save_to_shadow_map+0x50/0xe0 [nilfs2] nilfs_clean_segments+0xee/0x5d0 [nilfs2] nilfs_ioctl_clean_segments.isra.19+0xb08/0xf40 [nilfs2] nilfs_ioctl+0xc52/0xfb0 [nilfs2] __x64_sys_ioctl+0x11d/0x170 do_syscall_64+0x3a/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae This fixes the remaining warning by using inode objects to hold those page caches. Link: https://lkml.kernel.org/r/1647867427-30498-3-git-send-email-konishi.ryusuke@xxxxxxxxx Signed-off-by: Ryusuke Konishi <konishi.ryusuke@xxxxxxxxx> Tested-by: Ryusuke Konishi <konishi.ryusuke@xxxxxxxxx> Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx> Cc: David Hildenbrand <david@xxxxxxxxxx> Cc: Hao Sun <sunhao.th@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/nilfs2/dat.c | 4 ++ fs/nilfs2/inode.c | 63 +++++++++++++++++++++++++++++++++++++++++--- fs/nilfs2/mdt.c | 38 ++++++++++++++++++-------- fs/nilfs2/mdt.h | 6 +--- fs/nilfs2/nilfs.h | 2 + 5 files changed, 92 insertions(+), 21 deletions(-) --- a/fs/nilfs2/dat.c~nilfs2-fix-lockdep-warnings-during-disk-space-reclamation +++ a/fs/nilfs2/dat.c @@ -497,7 +497,9 @@ int nilfs_dat_read(struct super_block *s di = NILFS_DAT_I(dat); lockdep_set_class(&di->mi.mi_sem, &dat_lock_key); nilfs_palloc_setup_cache(dat, &di->palloc_cache); - nilfs_mdt_setup_shadow_map(dat, &di->shadow); + err = nilfs_mdt_setup_shadow_map(dat, &di->shadow); + if (err) + goto failed; err = nilfs_read_inode_common(dat, raw_inode); if (err) --- a/fs/nilfs2/inode.c~nilfs2-fix-lockdep-warnings-during-disk-space-reclamation +++ a/fs/nilfs2/inode.c @@ -30,6 +30,7 @@ * @root: pointer on NILFS root object (mounted checkpoint) * @for_gc: inode for GC flag * @for_btnc: inode for B-tree node cache flag + * @for_shadow: inode for shadowed page cache flag */ struct nilfs_iget_args { u64 ino; @@ -37,6 +38,7 @@ struct nilfs_iget_args { struct nilfs_root *root; bool for_gc; bool for_btnc; + bool for_shadow; }; static int nilfs_iget_test(struct inode *inode, void *opaque); @@ -315,7 +317,7 @@ static int nilfs_insert_inode_locked(str { struct nilfs_iget_args args = { .ino = ino, .root = root, .cno = 0, .for_gc = false, - .for_btnc = false + .for_btnc = false, .for_shadow = false }; return insert_inode_locked4(inode, ino, nilfs_iget_test, &args); @@ -534,6 +536,12 @@ static int nilfs_iget_test(struct inode } else if (args->for_btnc) { return 0; } + if (test_bit(NILFS_I_SHADOW, &ii->i_state)) { + if (!args->for_shadow) + return 0; + } else if (args->for_shadow) { + return 0; + } if (!test_bit(NILFS_I_GCINODE, &ii->i_state)) return !args->for_gc; @@ -555,6 +563,8 @@ static int nilfs_iget_set(struct inode * NILFS_I(inode)->i_state = BIT(NILFS_I_GCINODE); if (args->for_btnc) NILFS_I(inode)->i_state |= BIT(NILFS_I_BTNC); + if (args->for_shadow) + NILFS_I(inode)->i_state |= BIT(NILFS_I_SHADOW); return 0; } @@ -563,7 +573,7 @@ struct inode *nilfs_ilookup(struct super { struct nilfs_iget_args args = { .ino = ino, .root = root, .cno = 0, .for_gc = false, - .for_btnc = false + .for_btnc = false, .for_shadow = false }; return ilookup5(sb, ino, nilfs_iget_test, &args); @@ -574,7 +584,7 @@ struct inode *nilfs_iget_locked(struct s { struct nilfs_iget_args args = { .ino = ino, .root = root, .cno = 0, .for_gc = false, - .for_btnc = false + .for_btnc = false, .for_shadow = false }; return iget5_locked(sb, ino, nilfs_iget_test, nilfs_iget_set, &args); @@ -606,7 +616,7 @@ struct inode *nilfs_iget_for_gc(struct s { struct nilfs_iget_args args = { .ino = ino, .root = NULL, .cno = cno, .for_gc = true, - .for_btnc = false + .for_btnc = false, .for_shadow = false }; struct inode *inode; int err; @@ -653,6 +663,7 @@ int nilfs_attach_btree_node_cache(struct args.cno = ii->i_cno; args.for_gc = test_bit(NILFS_I_GCINODE, &ii->i_state) != 0; args.for_btnc = true; + args.for_shadow = test_bit(NILFS_I_SHADOW, &ii->i_state) != 0; btnc_inode = iget5_locked(inode->i_sb, inode->i_ino, nilfs_iget_test, nilfs_iget_set, &args); @@ -688,6 +699,50 @@ void nilfs_detach_btree_node_cache(struc } } +/** + * nilfs_iget_for_shadow - obtain inode for shadow mapping + * @inode: inode object that uses shadow mapping + * + * nilfs_iget_for_shadow() allocates a pair of inodes that holds page + * caches for shadow mapping. The page cache for data pages is set up + * in one inode and the one for b-tree node pages is set up in the + * other inode, which is attached to the former inode. + * + * Return Value: On success, a pointer to the inode for data pages is + * returned. On errors, one of the following negative error code is returned + * in a pointer type. + * + * %-ENOMEM - Insufficient memory available. + */ +struct inode *nilfs_iget_for_shadow(struct inode *inode) +{ + struct nilfs_iget_args args = { + .ino = inode->i_ino, .root = NULL, .cno = 0, .for_gc = false, + .for_btnc = false, .for_shadow = true + }; + struct inode *s_inode; + int err; + + s_inode = iget5_locked(inode->i_sb, inode->i_ino, nilfs_iget_test, + nilfs_iget_set, &args); + if (unlikely(!s_inode)) + return ERR_PTR(-ENOMEM); + if (!(s_inode->i_state & I_NEW)) + return inode; + + NILFS_I(s_inode)->i_flags = 0; + memset(NILFS_I(s_inode)->i_bmap, 0, sizeof(struct nilfs_bmap)); + mapping_set_gfp_mask(s_inode->i_mapping, GFP_NOFS); + + err = nilfs_attach_btree_node_cache(s_inode); + if (unlikely(err)) { + iget_failed(s_inode); + return ERR_PTR(err); + } + unlock_new_inode(s_inode); + return s_inode; +} + void nilfs_write_inode_common(struct inode *inode, struct nilfs_inode *raw_inode, int has_bmap) { --- a/fs/nilfs2/mdt.c~nilfs2-fix-lockdep-warnings-during-disk-space-reclamation +++ a/fs/nilfs2/mdt.c @@ -471,9 +471,18 @@ int nilfs_mdt_init(struct inode *inode, void nilfs_mdt_clear(struct inode *inode) { struct nilfs_mdt_info *mdi = NILFS_MDT(inode); + struct nilfs_shadow_map *shadow = mdi->mi_shadow; if (mdi->mi_palloc_cache) nilfs_palloc_destroy_cache(inode); + + if (shadow) { + struct inode *s_inode = shadow->inode; + + shadow->inode = NULL; + iput(s_inode); + mdi->mi_shadow = NULL; + } } /** @@ -507,12 +516,15 @@ int nilfs_mdt_setup_shadow_map(struct in struct nilfs_shadow_map *shadow) { struct nilfs_mdt_info *mi = NILFS_MDT(inode); + struct inode *s_inode; INIT_LIST_HEAD(&shadow->frozen_buffers); - address_space_init_once(&shadow->frozen_data); - nilfs_mapping_init(&shadow->frozen_data, inode); - address_space_init_once(&shadow->frozen_btnodes); - nilfs_mapping_init(&shadow->frozen_btnodes, inode); + + s_inode = nilfs_iget_for_shadow(inode); + if (IS_ERR(s_inode)) + return PTR_ERR(s_inode); + + shadow->inode = s_inode; mi->mi_shadow = shadow; return 0; } @@ -526,13 +538,14 @@ int nilfs_mdt_save_to_shadow_map(struct struct nilfs_mdt_info *mi = NILFS_MDT(inode); struct nilfs_inode_info *ii = NILFS_I(inode); struct nilfs_shadow_map *shadow = mi->mi_shadow; + struct inode *s_inode = shadow->inode; int ret; - ret = nilfs_copy_dirty_pages(&shadow->frozen_data, inode->i_mapping); + ret = nilfs_copy_dirty_pages(s_inode->i_mapping, inode->i_mapping); if (ret) goto out; - ret = nilfs_copy_dirty_pages(&shadow->frozen_btnodes, + ret = nilfs_copy_dirty_pages(NILFS_I(s_inode)->i_assoc_inode->i_mapping, ii->i_assoc_inode->i_mapping); if (ret) goto out; @@ -549,7 +562,7 @@ int nilfs_mdt_freeze_buffer(struct inode struct page *page; int blkbits = inode->i_blkbits; - page = grab_cache_page(&shadow->frozen_data, bh->b_page->index); + page = grab_cache_page(shadow->inode->i_mapping, bh->b_page->index); if (!page) return -ENOMEM; @@ -581,7 +594,7 @@ nilfs_mdt_get_frozen_buffer(struct inode struct page *page; int n; - page = find_lock_page(&shadow->frozen_data, bh->b_page->index); + page = find_lock_page(shadow->inode->i_mapping, bh->b_page->index); if (page) { if (page_has_buffers(page)) { n = bh_offset(bh) >> inode->i_blkbits; @@ -622,11 +635,11 @@ void nilfs_mdt_restore_from_shadow_map(s nilfs_palloc_clear_cache(inode); nilfs_clear_dirty_pages(inode->i_mapping, true); - nilfs_copy_back_pages(inode->i_mapping, &shadow->frozen_data); + nilfs_copy_back_pages(inode->i_mapping, shadow->inode->i_mapping); nilfs_clear_dirty_pages(ii->i_assoc_inode->i_mapping, true); nilfs_copy_back_pages(ii->i_assoc_inode->i_mapping, - &shadow->frozen_btnodes); + NILFS_I(shadow->inode)->i_assoc_inode->i_mapping); nilfs_bmap_restore(ii->i_bmap, &shadow->bmap_store); @@ -641,10 +654,11 @@ void nilfs_mdt_clear_shadow_map(struct i { struct nilfs_mdt_info *mi = NILFS_MDT(inode); struct nilfs_shadow_map *shadow = mi->mi_shadow; + struct inode *shadow_btnc_inode = NILFS_I(shadow->inode)->i_assoc_inode; down_write(&mi->mi_sem); nilfs_release_frozen_buffers(shadow); - truncate_inode_pages(&shadow->frozen_data, 0); - truncate_inode_pages(&shadow->frozen_btnodes, 0); + truncate_inode_pages(shadow->inode->i_mapping, 0); + truncate_inode_pages(shadow_btnc_inode->i_mapping, 0); up_write(&mi->mi_sem); } --- a/fs/nilfs2/mdt.h~nilfs2-fix-lockdep-warnings-during-disk-space-reclamation +++ a/fs/nilfs2/mdt.h @@ -18,14 +18,12 @@ /** * struct nilfs_shadow_map - shadow mapping of meta data file * @bmap_store: shadow copy of bmap state - * @frozen_data: shadowed dirty data pages - * @frozen_btnodes: shadowed dirty b-tree nodes' pages + * @inode: holder of page caches used in shadow mapping * @frozen_buffers: list of frozen buffers */ struct nilfs_shadow_map { struct nilfs_bmap_store bmap_store; - struct address_space frozen_data; - struct address_space frozen_btnodes; + struct inode *inode; struct list_head frozen_buffers; }; --- a/fs/nilfs2/nilfs.h~nilfs2-fix-lockdep-warnings-during-disk-space-reclamation +++ a/fs/nilfs2/nilfs.h @@ -92,6 +92,7 @@ enum { NILFS_I_BMAP, /* has bmap and btnode_cache */ NILFS_I_GCINODE, /* inode for GC, on memory only */ NILFS_I_BTNC, /* inode for btree node cache */ + NILFS_I_SHADOW, /* inode for shadowed page cache */ }; /* @@ -263,6 +264,7 @@ extern struct inode *nilfs_iget_for_gc(s unsigned long ino, __u64 cno); int nilfs_attach_btree_node_cache(struct inode *inode); void nilfs_detach_btree_node_cache(struct inode *inode); +struct inode *nilfs_iget_for_shadow(struct inode *inode); extern void nilfs_update_inode(struct inode *, struct buffer_head *, int); extern void nilfs_truncate(struct inode *); extern void nilfs_evict_inode(struct inode *); _
