Re: [PATCH 4/8] xfs: use memalloc_nofs_{save,restore} instead of memalloc_noio*
From: Darrick J. Wong <hidden>
Date: 2017-01-09 20:59:07
Also in:
ceph-devel, linux-btrfs, linux-f2fs-devel, linux-fsdevel, linux-mm, linux-nfs, linux-xfs, lkml
On Fri, Jan 06, 2017 at 03:11:03PM +0100, Michal Hocko wrote:
From: Michal Hocko <mhocko@suse.com>
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.
Changes since v1
- s@memalloc_noio_restore@memalloc_nofs_restore@ in _xfs_buf_map_pages
as per Brian Foster
Signed-off-by: Michal Hocko <mhocko@suse.com>Reviewed-by: Darrick J. Wong <redacted>
quoted hunk ↗ jump to hunk
--- fs/xfs/kmem.c | 10 +++++----- fs/xfs/xfs_buf.c | 8 ++++---- 2 files changed, 9 insertions(+), 9 deletions(-)diff --git a/fs/xfs/kmem.c b/fs/xfs/kmem.c index a76a05dae96b..d69ed5e76621 100644 --- a/fs/xfs/kmem.c +++ b/fs/xfs/kmem.c@@ -65,7 +65,7 @@ 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;@@ -80,14 +80,14 @@ kmem_zalloc_large(size_t size, xfs_km_flags_t flags) * context via PF_MEMALLOC_NOIO 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; }diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c index 7f0a01f7b592..8cb8dd4cdfd8 100644 --- a/fs/xfs/xfs_buf.c +++ b/fs/xfs/xfs_buf.c@@ -441,17 +441,17 @@ _xfs_buf_map_pages( bp->b_addr = NULL; } else { int retried = 0; - unsigned noio_flag; + unsigned nofs_flag; /* * vm_map_ram() will allocate auxillary structures (e.g. * pagetables) with GFP_KERNEL, yet we are likely to 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 + * that we are in such a context via PF_MEMALLOC_NOFS to prevent * memory reclaim re-entering the filesystem here and * potentially deadlocking. */ - noio_flag = memalloc_noio_save(); + nofs_flag = memalloc_nofs_save(); do { bp->b_addr = vm_map_ram(bp->b_pages, bp->b_page_count, -1, PAGE_KERNEL);@@ -459,7 +459,7 @@ _xfs_buf_map_pages( break; vm_unmap_aliases(); } while (retried++ <= 1); - memalloc_noio_restore(noio_flag); + memalloc_nofs_restore(nofs_flag); if (!bp->b_addr) return -ENOMEM;-- 2.11.0 -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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