From: Michal Hocko <mhocko@xxxxxxxx>
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
Acked-by: Vlastimil Babka <vbabka@xxxxxxx>
Reviewed-by: Brian Foster <bfoster@xxxxxxxxxx>
Reviewed-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
Signed-off-by: Michal Hocko <mhocko@xxxxxxxx>
---
fs/xfs/kmem.c | 12 ++++++------
fs/xfs/xfs_buf.c | 8 ++++----
2 files changed, 10 insertions(+), 10 deletions(-)
diff --git a/fs/xfs/kmem.c b/fs/xfs/kmem.c
index e14da724a0b5..6b7b04468aa8 100644
--- a/fs/xfs/kmem.c
+++ b/fs/xfs/kmem.c
@@ -66,7 +66,7 @@ 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;
@@ -78,17 +78,17 @@ 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;
}
diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index b6208728ba39..ca09061369cb 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -443,17 +443,17 @@ _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);
@@ -461,7 +461,7 @@ _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
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