From 9ba1fb2c602a6f2323e3a08ec8e7a8e33bf335f4 Mon Sep 17 00:00:00 2001 From: Michal Hocko Date: Wed, 3 May 2017 14:53:19 -0700 Subject: xfs: use memalloc_nofs_{save,restore} instead of memalloc_noio* kmem_zalloc_large and _xfs_buf_map_pages use memalloc_noio_{save,restore} API to prevent from reclaim recursion into the fs because vmalloc can invoke unconditional GFP_KERNEL allocations and these functions might be called from the NOFS contexts. The memalloc_noio_save will enforce GFP_NOIO context which is even weaker than GFP_NOFS and that seems to be unnecessary. Let's use memalloc_nofs_{save,restore} instead as it should provide exactly what we need here - implicit GFP_NOFS context. Link: http://lkml.kernel.org/r/20170306131408.9828-6-mhocko@kernel.org Signed-off-by: Michal Hocko Reviewed-by: Brian Foster Reviewed-by: Darrick J. Wong Acked-by: Vlastimil Babka Cc: Dave Chinner Cc: Theodore Ts'o Cc: Chris Mason Cc: David Sterba Cc: Jan Kara Cc: Nikolay Borisov Cc: Peter Zijlstra Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/xfs/kmem.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'fs/xfs/kmem.c') diff --git a/fs/xfs/kmem.c b/fs/xfs/kmem.c index d0ac1a065539..780fc8986dab 100644 --- a/fs/xfs/kmem.c +++ b/fs/xfs/kmem.c @@ -48,7 +48,7 @@ kmem_alloc(size_t size, xfs_km_flags_t flags) void * kmem_zalloc_large(size_t size, xfs_km_flags_t flags) { - unsigned noio_flag = 0; + unsigned nofs_flag = 0; void *ptr; gfp_t lflags; @@ -60,17 +60,17 @@ kmem_zalloc_large(size_t size, xfs_km_flags_t flags) * __vmalloc() will allocate data pages and auxillary structures (e.g. * pagetables) with GFP_KERNEL, yet we may be under GFP_NOFS context * here. Hence we need to tell memory reclaim that we are in such a - * context via PF_MEMALLOC_NOIO to prevent memory reclaim re-entering + * context via PF_MEMALLOC_NOFS to prevent memory reclaim re-entering * the filesystem here and potentially deadlocking. */ - if ((current->flags & PF_MEMALLOC_NOFS) || (flags & KM_NOFS)) - noio_flag = memalloc_noio_save(); + if (flags & KM_NOFS) + nofs_flag = memalloc_nofs_save(); lflags = kmem_flags_convert(flags); ptr = __vmalloc(size, lflags | __GFP_HIGHMEM | __GFP_ZERO, PAGE_KERNEL); - if ((current->flags & PF_MEMALLOC_NOFS) || (flags & KM_NOFS)) - memalloc_noio_restore(noio_flag); + if (flags & KM_NOFS) + memalloc_nofs_restore(nofs_flag); return ptr; } -- cgit v1.2.3