btrfs: fix integer overflow in calc_reclaim_items_nr
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: 70e7af2 ("Btrfs: fix delalloc accounting leak caused by u32 overflow")
Signed-off-by: Chris Mason <clm@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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);