xfs: make qi_dquots a 64-bit value

qi_dquots counts all quotas in the file system, which can be up to
3 * UINT_MAX and overflow a 32-bit counter, but can't be negative.
Make qi_dquots a uint64_t, and saturate the value to UINT_MAX for
userspace reporting.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>

Author: Christoph Hellwig

fs/xfs/xfs_qm.h

@@ -57,7 +57,7 @@ struct xfs_quotainfo {
 	struct xfs_inode	*qi_pquotaip;	/* project quota inode */
 	struct xfs_inode	*qi_dirip;	/* quota metadir */
 	struct list_lru		qi_lru;
-	int			qi_dquots;
+	uint64_t		qi_dquots;
 	struct mutex		qi_quotaofflock;/* to serialize quotaoff */
 	xfs_filblks_t		qi_dqchunklen;	/* # BBs in a chunk of dqs */
 	uint			qi_dqperchunk;	/* # ondisk dq in above chunk */

fs/xfs/xfs_quotaops.c

@@ -65,7 +65,7 @@ xfs_fs_get_quota_state(
 	memset(state, 0, sizeof(*state));
 	if (!XFS_IS_QUOTA_ON(mp))
 		return 0;
-	state->s_incoredqs = q->qi_dquots;
+	state->s_incoredqs = min_t(uint64_t, q->qi_dquots, UINT_MAX);
 	if (XFS_IS_UQUOTA_ON(mp))
 		state->s_state[USRQUOTA].flags |= QCI_ACCT_ENABLED;
 	if (XFS_IS_UQUOTA_ENFORCED(mp))