diff options
| -rw-r--r-- | fs/xfs/kmem.c | 21 | ||||
| -rw-r--r-- | fs/xfs/xfs_buf.c | 11 |
2 files changed, 31 insertions, 1 deletions
diff --git a/fs/xfs/kmem.c b/fs/xfs/kmem.c index 66a36befc5c0..844e288b9576 100644 --- a/fs/xfs/kmem.c +++ b/fs/xfs/kmem.c @@ -65,12 +65,31 @@ 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; void *ptr; + gfp_t lflags; ptr = kmem_zalloc(size, flags | KM_MAYFAIL); if (ptr) return ptr; - return vzalloc(size); + + /* + * __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 + * the filesystem here and potentially deadlocking. + */ + if ((current->flags & PF_FSTRANS) || (flags & KM_NOFS)) + noio_flag = memalloc_noio_save(); + + lflags = kmem_flags_convert(flags); + ptr = __vmalloc(size, lflags | __GFP_HIGHMEM | __GFP_ZERO, PAGE_KERNEL); + + if ((current->flags & PF_FSTRANS) || (flags & KM_NOFS)) + memalloc_noio_restore(noio_flag); + + return ptr; } void diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c index 9c061ef2b0d9..107f2fdfe41f 100644 --- a/fs/xfs/xfs_buf.c +++ b/fs/xfs/xfs_buf.c @@ -396,7 +396,17 @@ _xfs_buf_map_pages( bp->b_addr = NULL; } else { int retried = 0; + unsigned noio_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 + * memory reclaim re-entering the filesystem here and + * potentially deadlocking. + */ + noio_flag = memalloc_noio_save(); do { bp->b_addr = vm_map_ram(bp->b_pages, bp->b_page_count, -1, PAGE_KERNEL); @@ -404,6 +414,7 @@ _xfs_buf_map_pages( break; vm_unmap_aliases(); } while (retried++ <= 1); + memalloc_noio_restore(noio_flag); if (!bp->b_addr) return -ENOMEM; |