diff mbox

btrfs: fix integer overflow in calc_reclaim_items_nr

Message ID 20170623143240.1245989-1-clm@fb.com (mailing list archive)
State New, archived
Headers show

Commit Message

Chris Mason June 23, 2017, 2:32 p.m. UTC 
Dave Jones hit a WARN_ON(nr < 0) in btrfs_wait_ordered_roots() with
v4.12-rc6.  This was because commit 70e7af244 made it possible for
calc_reclaim_items_nr() to return a negative number.  It's not really a
bug in that commit, it just didn't go far enough down the stack to find
all the possible 64->32 bit overflows.

This switches calc_reclaim_items_nr() to return a u64 and changes everyone
that uses the results of that math to u64 as well.

Reported-by: Dave Jones <davej@codemonkey.org.uk>
Fixes: 70e7af244f24c94604ef6eca32ad297632018583
Signed-off-by: Chris Mason <clm@fb.com>
---
 fs/btrfs/dev-replace.c  |  4 ++--
 fs/btrfs/extent-tree.c  | 10 +++++-----
 fs/btrfs/ioctl.c        |  2 +-
 fs/btrfs/ordered-data.c | 17 ++++++++---------
 fs/btrfs/ordered-data.h |  4 ++--
 fs/btrfs/qgroup.c       |  2 +-
 fs/btrfs/relocation.c   |  2 +-
 fs/btrfs/scrub.c        |  2 +-
 fs/btrfs/super.c        |  2 +-
 fs/btrfs/transaction.c  |  2 +-
 10 files changed, 23 insertions(+), 24 deletions(-)

Comments

Holger Hoffstätte June 23, 2017, 3:29 p.m. UTC | #1 
On 06/23/17 16:32, Chris Mason wrote:
[..]
> -static inline int calc_reclaim_items_nr(struct btrfs_fs_info *fs_info,
> +static inline u64 calc_reclaim_items_nr(struct btrfs_fs_info *fs_info,
>  					u64 to_reclaim)
>  {
>  	u64 bytes;
> -	int nr;
> +	u64 nr;
>  
>  	bytes = btrfs_calc_trans_metadata_size(fs_info, 1);
>  	nr = (int)div64_u64(to_reclaim, bytes);
        ^^^^^^^^^^

Isn't this a bit odd? I can't even tell whether it matters, just randomly
noticed it because I genuinely dislike type casts..

-h
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David Sterba June 23, 2017, 3:59 p.m. UTC | #2 
On Fri, Jun 23, 2017 at 05:29:56PM +0200, Holger Hoffstätte wrote:
> On 06/23/17 16:32, Chris Mason wrote:
> [..]
> > -static inline int calc_reclaim_items_nr(struct btrfs_fs_info *fs_info,
> > +static inline u64 calc_reclaim_items_nr(struct btrfs_fs_info *fs_info,
> >  					u64 to_reclaim)
> >  {
> >  	u64 bytes;
> > -	int nr;
> > +	u64 nr;
> >  
> >  	bytes = btrfs_calc_trans_metadata_size(fs_info, 1);
> >  	nr = (int)div64_u64(to_reclaim, bytes);
>         ^^^^^^^^^^
> 
> Isn't this a bit odd? I can't even tell whether it matters, just randomly
> noticed it because I genuinely dislike type casts..

I think the typecast shold be dropped, now that nr is u64.
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Chris Mason June 23, 2017, 4:40 p.m. UTC | #3 
On 06/23/2017 11:29 AM, Holger Hoffstätte wrote:
> On 06/23/17 16:32, Chris Mason wrote:
> [..]
>> -static inline int calc_reclaim_items_nr(struct btrfs_fs_info *fs_info,
>> +static inline u64 calc_reclaim_items_nr(struct btrfs_fs_info *fs_info,
>>  					u64 to_reclaim)
>>  {
>>  	u64 bytes;
>> -	int nr;
>> +	u64 nr;
>>
>>  	bytes = btrfs_calc_trans_metadata_size(fs_info, 1);
>>  	nr = (int)div64_u64(to_reclaim, bytes);
>         ^^^^^^^^^^
>
> Isn't this a bit odd? I can't even tell whether it matters, just randomly
> noticed it because I genuinely dislike type casts..
>

Crud, yes that's broken.  Thanks!

-chris

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diff mbox

Patch

diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c
index 5fe1ca8..bee3ede 100644
--- a/fs/btrfs/dev-replace.c
+++ b/fs/btrfs/dev-replace.c
@@ -388,7 +388,7 @@  int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info,
 	if (ret)
 		btrfs_err(fs_info, "kobj add dev failed %d", ret);
 
-	btrfs_wait_ordered_roots(fs_info, -1, 0, (u64)-1);
+	btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1);
 
 	/* force writing the updated state information to disk */
 	trans = btrfs_start_transaction(root, 0);
@@ -507,7 +507,7 @@  static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info,
 		mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
 		return ret;
 	}
-	btrfs_wait_ordered_roots(fs_info, -1, 0, (u64)-1);
+	btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1);
 
 	trans = btrfs_start_transaction(root, 0);
 	if (IS_ERR(trans)) {
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 33d979e9..d675324 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -4238,7 +4238,7 @@  int btrfs_alloc_data_chunk_ondemand(struct btrfs_inode *inode, u64 bytes)
 
 			if (need_commit > 0) {
 				btrfs_start_delalloc_roots(fs_info, 0, -1);
-				btrfs_wait_ordered_roots(fs_info, -1, 0,
+				btrfs_wait_ordered_roots(fs_info, U64_MAX, 0,
 							 (u64)-1);
 			}
 
@@ -4698,11 +4698,11 @@  static void btrfs_writeback_inodes_sb_nr(struct btrfs_fs_info *fs_info,
 	}
 }
 
-static inline int calc_reclaim_items_nr(struct btrfs_fs_info *fs_info,
+static inline u64 calc_reclaim_items_nr(struct btrfs_fs_info *fs_info,
 					u64 to_reclaim)
 {
 	u64 bytes;
-	int nr;
+	u64 nr;
 
 	bytes = btrfs_calc_trans_metadata_size(fs_info, 1);
 	nr = (int)div64_u64(to_reclaim, bytes);
@@ -4725,15 +4725,15 @@  static void shrink_delalloc(struct btrfs_root *root, u64 to_reclaim, u64 orig,
 	struct btrfs_trans_handle *trans;
 	u64 delalloc_bytes;
 	u64 max_reclaim;
+	u64 items;
 	long time_left;
 	unsigned long nr_pages;
 	int loops;
-	int items;
 	enum btrfs_reserve_flush_enum flush;
 
 	/* Calc the number of the pages we need flush for space reservation */
 	items = calc_reclaim_items_nr(fs_info, to_reclaim);
-	to_reclaim = (u64)items * EXTENT_SIZE_PER_ITEM;
+	to_reclaim = items * EXTENT_SIZE_PER_ITEM;
 
 	trans = (struct btrfs_trans_handle *)current->journal_info;
 	block_rsv = &fs_info->delalloc_block_rsv;
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index e176375..7712217 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -689,7 +689,7 @@  static int create_snapshot(struct btrfs_root *root, struct inode *dir,
 	if (ret)
 		goto dec_and_free;
 
-	btrfs_wait_ordered_extents(root, -1, 0, (u64)-1);
+	btrfs_wait_ordered_extents(root, U64_MAX, 0, (u64)-1);
 
 	btrfs_init_block_rsv(&pending_snapshot->block_rsv,
 			     BTRFS_BLOCK_RSV_TEMP);
diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c
index 7b40e2e..a3aca49 100644
--- a/fs/btrfs/ordered-data.c
+++ b/fs/btrfs/ordered-data.c
@@ -663,7 +663,7 @@  static void btrfs_run_ordered_extent_work(struct btrfs_work *work)
  * wait for all the ordered extents in a root.  This is done when balancing
  * space between drives.
  */
-int btrfs_wait_ordered_extents(struct btrfs_root *root, int nr,
+u64 btrfs_wait_ordered_extents(struct btrfs_root *root, u64 nr,
 			       const u64 range_start, const u64 range_len)
 {
 	struct btrfs_fs_info *fs_info = root->fs_info;
@@ -671,7 +671,7 @@  int btrfs_wait_ordered_extents(struct btrfs_root *root, int nr,
 	LIST_HEAD(skipped);
 	LIST_HEAD(works);
 	struct btrfs_ordered_extent *ordered, *next;
-	int count = 0;
+	u64 count = 0;
 	const u64 range_end = range_start + range_len;
 
 	mutex_lock(&root->ordered_extent_mutex);
@@ -701,7 +701,7 @@  int btrfs_wait_ordered_extents(struct btrfs_root *root, int nr,
 
 		cond_resched();
 		spin_lock(&root->ordered_extent_lock);
-		if (nr != -1)
+		if (nr != U64_MAX)
 			nr--;
 		count++;
 	}
@@ -720,13 +720,13 @@  int btrfs_wait_ordered_extents(struct btrfs_root *root, int nr,
 	return count;
 }
 
-int btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, int nr,
-			      const u64 range_start, const u64 range_len)
+u64 btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, u64 nr,
+			     const u64 range_start, const u64 range_len)
 {
 	struct btrfs_root *root;
 	struct list_head splice;
-	int done;
-	int total_done = 0;
+	u64 total_done = 0;
+	u64 done;
 
 	INIT_LIST_HEAD(&splice);
 
@@ -748,9 +748,8 @@  int btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, int nr,
 		total_done += done;
 
 		spin_lock(&fs_info->ordered_root_lock);
-		if (nr != -1) {
+		if (nr != U64_MAX) {
 			nr -= done;
-			WARN_ON(nr < 0);
 		}
 	}
 	list_splice_tail(&splice, &fs_info->ordered_roots);
diff --git a/fs/btrfs/ordered-data.h b/fs/btrfs/ordered-data.h
index e0c1d5b..56c4c0e 100644
--- a/fs/btrfs/ordered-data.h
+++ b/fs/btrfs/ordered-data.h
@@ -200,9 +200,9 @@  int btrfs_ordered_update_i_size(struct inode *inode, u64 offset,
 				struct btrfs_ordered_extent *ordered);
 int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr,
 			   u32 *sum, int len);
-int btrfs_wait_ordered_extents(struct btrfs_root *root, int nr,
+u64 btrfs_wait_ordered_extents(struct btrfs_root *root, u64 nr,
 			       const u64 range_start, const u64 range_len);
-int btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, int nr,
+u64 btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, u64 nr,
 			      const u64 range_start, const u64 range_len);
 void btrfs_get_logged_extents(struct btrfs_inode *inode,
 			      struct list_head *logged_list,
diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index deffbeb..25ef976 100644
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -2376,7 +2376,7 @@  static int qgroup_reserve(struct btrfs_root *root, u64 num_bytes, bool enforce)
 				ret = btrfs_start_delalloc_inodes(root, 0);
 				if (ret)
 					return ret;
-				btrfs_wait_ordered_extents(root, -1, 0, (u64)-1);
+				btrfs_wait_ordered_extents(root, U64_MAX, 0, (u64)-1);
 				trans = btrfs_join_transaction(root);
 				if (IS_ERR(trans))
 					return PTR_ERR(trans);
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index d60df51..c16abd7 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -4372,7 +4372,7 @@  int btrfs_relocate_block_group(struct btrfs_fs_info *fs_info, u64 group_start)
 
 	btrfs_wait_block_group_reservations(rc->block_group);
 	btrfs_wait_nocow_writers(rc->block_group);
-	btrfs_wait_ordered_roots(fs_info, -1,
+	btrfs_wait_ordered_roots(fs_info, U64_MAX,
 				 rc->block_group->key.objectid,
 				 rc->block_group->key.offset);
 
diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index c7b45eb..b8a079e 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -3859,7 +3859,7 @@  int scrub_enumerate_chunks(struct scrub_ctx *sctx,
 			 */
 			btrfs_wait_block_group_reservations(cache);
 			btrfs_wait_nocow_writers(cache);
-			ret = btrfs_wait_ordered_roots(fs_info, -1,
+			ret = btrfs_wait_ordered_roots(fs_info, U64_MAX,
 						       cache->key.objectid,
 						       cache->key.offset);
 			if (ret > 0) {
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 4f1cdd5..0066f2d 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -1187,7 +1187,7 @@  int btrfs_sync_fs(struct super_block *sb, int wait)
 		return 0;
 	}
 
-	btrfs_wait_ordered_roots(fs_info, -1, 0, (u64)-1);
+	btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1);
 
 	trans = btrfs_attach_transaction_barrier(root);
 	if (IS_ERR(trans)) {
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 2168654..0a3023a 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -1926,7 +1926,7 @@  static inline int btrfs_start_delalloc_flush(struct btrfs_fs_info *fs_info)
 static inline void btrfs_wait_delalloc_flush(struct btrfs_fs_info *fs_info)
 {
 	if (btrfs_test_opt(fs_info, FLUSHONCOMMIT))
-		btrfs_wait_ordered_roots(fs_info, -1, 0, (u64)-1);
+		btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1);
 }
 
 static inline void