Commit acd1ac3a authored Oct 01, 2020 by Darrick J. Wong

xfs: limit entries returned when counting fsmap records



If userspace asked fsmap to count the number of entries, we cannot
return more than UINT_MAX entries because fmh_entries is u32.
Therefore, stop counting if we hit this limit or else we will waste time
to return truncated results.

Fixes: e89c0413 ("xfs: implement the GETFSMAP ioctl")
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chandan Babu R <chandanrlinux@gmail.com>

parent 74f4d6a1

fs/xfs/xfs_fsmap.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -256,6 +256,9 @@ xfs_getfsmap_helper(

		/* Are we just counting mappings? */
		if (info->head->fmh_count == 0) {
		if (info->head->fmh_entries == UINT_MAX)
		return -ECANCELED;

		if (rec_daddr > info->next_daddr)
		info->head->fmh_entries++;

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