Skip to content

Commit

Permalink
nilfs2: fix lockdep warnings during disk space reclamation
Browse files Browse the repository at this point in the history 
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:
    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

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@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hao Sun <sunhao.th@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
  • Loading branch information
@konis @torvalds
konis authored and torvalds committed Apr 1, 2022
1 parent e897be1 commit 6e21193
Show file tree
Hide file tree
Showing 5 changed files with 92 additions and 21 deletions.
4 changes: 3 additions & 1 deletion fs/nilfs2/dat.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -497,7 +497,9 @@ int nilfs_dat_read(struct super_block *sb, size_t entry_size,
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)
Expand Down
63 changes: 59 additions & 4 deletions fs/nilfs2/inode.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -30,13 +30,15 @@
* @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;
__u64 cno;
struct nilfs_root *root;
bool for_gc;
bool for_btnc;
bool for_shadow;
};

static int nilfs_iget_test(struct inode *inode, void *opaque);
Expand Down Expand Up @@ -315,7 +317,7 @@ static int nilfs_insert_inode_locked(struct inode *inode,
{
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);
Expand Down Expand Up @@ -534,6 +536,12 @@ static int nilfs_iget_test(struct inode *inode, void *opaque)
} 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;
Expand All @@ -555,6 +563,8 @@ static int nilfs_iget_set(struct inode *inode, void *opaque)
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;
}

Expand All @@ -563,7 +573,7 @@ struct inode *nilfs_ilookup(struct super_block *sb, struct nilfs_root *root,
{
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);
Expand All @@ -574,7 +584,7 @@ struct inode *nilfs_iget_locked(struct super_block *sb, struct nilfs_root *root,
{
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);
Expand Down Expand Up @@ -606,7 +616,7 @@ struct inode *nilfs_iget_for_gc(struct super_block *sb, unsigned long ino,
{
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;
Expand Down Expand Up @@ -653,6 +663,7 @@ int nilfs_attach_btree_node_cache(struct inode *inode)
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);
Expand Down Expand Up @@ -688,6 +699,50 @@ void nilfs_detach_btree_node_cache(struct inode *inode)
}
}

/**
* 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)
{
Expand Down
38 changes: 26 additions & 12 deletions fs/nilfs2/mdt.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -471,9 +471,18 @@ int nilfs_mdt_init(struct inode *inode, gfp_t gfp_mask, size_t objsz)
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;
}
}

/**
Expand Down Expand Up @@ -507,12 +516,15 @@ int nilfs_mdt_setup_shadow_map(struct inode *inode,
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;
}
Expand All @@ -526,13 +538,14 @@ int nilfs_mdt_save_to_shadow_map(struct inode *inode)
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;
Expand All @@ -549,7 +562,7 @@ int nilfs_mdt_freeze_buffer(struct inode *inode, struct buffer_head *bh)
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;

Expand Down Expand Up @@ -581,7 +594,7 @@ nilfs_mdt_get_frozen_buffer(struct inode *inode, struct buffer_head *bh)
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;
Expand Down Expand Up @@ -622,11 +635,11 @@ void nilfs_mdt_restore_from_shadow_map(struct inode *inode)
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);

Expand All @@ -641,10 +654,11 @@ void nilfs_mdt_clear_shadow_map(struct inode *inode)
{
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);
}
6 changes: 2 additions & 4 deletions fs/nilfs2/mdt.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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;
};

Expand Down
2 changes: 2 additions & 0 deletions fs/nilfs2/nilfs.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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 */
};

/*
Expand Down Expand Up @@ -263,6 +264,7 @@ extern struct inode *nilfs_iget_for_gc(struct super_block *sb,
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 *);
Expand Down

0 comments on commit 6e21193

Please sign in to comment.