1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (c) 2000-2005 Silicon Graphics, Inc. 4 * All Rights Reserved. 5 */ 6 #include "xfs.h" 7 #include <linux/backing-dev.h> 8 #include "xfs_message.h" 9 #include "xfs_trace.h" 10 11 void * 12 kmem_alloc(size_t size, xfs_km_flags_t flags) 13 { 14 int retries = 0; 15 gfp_t lflags = kmem_flags_convert(flags); 16 void *ptr; 17 18 trace_kmem_alloc(size, flags, _RET_IP_); 19 20 do { 21 ptr = kmalloc(size, lflags); 22 if (ptr || (flags & KM_MAYFAIL)) 23 return ptr; 24 if (!(++retries % 100)) 25 xfs_err(NULL, 26 "%s(%u) possible memory allocation deadlock size %u in %s (mode:0x%x)", 27 current->comm, current->pid, 28 (unsigned int)size, __func__, lflags); 29 congestion_wait(BLK_RW_ASYNC, HZ/50); 30 } while (1); 31 } 32 33 34 /* 35 * __vmalloc() will allocate data pages and auxiliary structures (e.g. 36 * pagetables) with GFP_KERNEL, yet we may be under GFP_NOFS context here. Hence 37 * we need to tell memory reclaim that we are in such a context via 38 * PF_MEMALLOC_NOFS to prevent memory reclaim re-entering the filesystem here 39 * and potentially deadlocking. 40 */ 41 static void * 42 __kmem_vmalloc(size_t size, xfs_km_flags_t flags) 43 { 44 unsigned nofs_flag = 0; 45 void *ptr; 46 gfp_t lflags = kmem_flags_convert(flags); 47 48 if (flags & KM_NOFS) 49 nofs_flag = memalloc_nofs_save(); 50 51 ptr = __vmalloc(size, lflags); 52 53 if (flags & KM_NOFS) 54 memalloc_nofs_restore(nofs_flag); 55 56 return ptr; 57 } 58 59 void * 60 kmem_alloc_large(size_t size, xfs_km_flags_t flags) 61 { 62 void *ptr; 63 64 trace_kmem_alloc_large(size, flags, _RET_IP_); 65 66 ptr = kmem_alloc(size, flags | KM_MAYFAIL); 67 if (ptr) 68 return ptr; 69 return __kmem_vmalloc(size, flags); 70 } 71