From: Dave Chinner <dchinner@xxxxxxxxxx> Cap longest extent to the largest we can allocate based on limits calculated at mount time. Dynamic state (such as finobt blocks) can result in the longest free extent exceeding the size we can allocate, and that results in failure to align full AG allocations when the AG is empty. Result: xfs_io-4413 [003] 426.412459: xfs_alloc_vextent_loopfailed: dev 8:96 agno 0 agbno 32 minlen 243968 maxlen 244000 mod 0 prod 1 minleft 1 total 262148 alignment 32 minalignslop 0 len 0 type NEAR_BNO otype START_BNO wasdel 0 wasfromfl 0 resv 0 datatype 0x5 firstblock 0xffffffffffffffff minlen and maxlen are now separated by the alignment size, and allocation fails because args.total > free space in the AG. Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx> Signed-off-by: Carlos Maiolino <cmaiolino@xxxxxxxxxx> --- fs/xfs/libxfs/xfs_alloc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c index 372ad55631fc..35b39fc863a0 100644 --- a/fs/xfs/libxfs/xfs_alloc.c +++ b/fs/xfs/libxfs/xfs_alloc.c @@ -1989,7 +1989,8 @@ xfs_alloc_longest_free_extent( * reservations and AGFL rules in place, we can return this extent. */ if (pag->pagf_longest > delta) - return pag->pagf_longest - delta; + return min_t(xfs_extlen_t, pag->pag_mount->m_ag_max_usable, + pag->pagf_longest - delta); /* Otherwise, let the caller try for 1 block if there's space. */ return pag->pagf_flcount > 0 || pag->pagf_longest > 0; -- 2.20.1