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- // SPDX-License-Identifier: GPL-2.0
- /*
- * Copyright (c) 2000-2005 Silicon Graphics, Inc.
- * All Rights Reserved.
- */
- #include "xfs.h"
- #include <linux/backing-dev.h>
- #include "xfs_message.h"
- #include "xfs_trace.h"
- void *
- kmem_alloc(size_t size, xfs_km_flags_t flags)
- {
- int retries = 0;
- gfp_t lflags = kmem_flags_convert(flags);
- void *ptr;
- trace_kmem_alloc(size, flags, _RET_IP_);
- do {
- ptr = kmalloc(size, lflags);
- if (ptr || (flags & KM_MAYFAIL))
- return ptr;
- if (!(++retries % 100))
- xfs_err(NULL,
- "%s(%u) possible memory allocation deadlock size %u in %s (mode:0x%x)",
- current->comm, current->pid,
- (unsigned int)size, __func__, lflags);
- congestion_wait(BLK_RW_ASYNC, HZ/50);
- } while (1);
- }
- /*
- * __vmalloc() will allocate data pages and auxiliary 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_NOFS to prevent memory reclaim re-entering the filesystem here
- * and potentially deadlocking.
- */
- static void *
- __kmem_vmalloc(size_t size, xfs_km_flags_t flags)
- {
- unsigned nofs_flag = 0;
- void *ptr;
- gfp_t lflags = kmem_flags_convert(flags);
- if (flags & KM_NOFS)
- nofs_flag = memalloc_nofs_save();
- ptr = __vmalloc(size, lflags);
- if (flags & KM_NOFS)
- memalloc_nofs_restore(nofs_flag);
- return ptr;
- }
- /*
- * Same as kmem_alloc_large, except we guarantee the buffer returned is aligned
- * to the @align_mask. We only guarantee alignment up to page size, we'll clamp
- * alignment at page size if it is larger. vmalloc always returns a PAGE_SIZE
- * aligned region.
- */
- void *
- kmem_alloc_io(size_t size, int align_mask, xfs_km_flags_t flags)
- {
- void *ptr;
- trace_kmem_alloc_io(size, flags, _RET_IP_);
- if (WARN_ON_ONCE(align_mask >= PAGE_SIZE))
- align_mask = PAGE_SIZE - 1;
- ptr = kmem_alloc(size, flags | KM_MAYFAIL);
- if (ptr) {
- if (!((uintptr_t)ptr & align_mask))
- return ptr;
- kfree(ptr);
- }
- return __kmem_vmalloc(size, flags);
- }
- void *
- kmem_alloc_large(size_t size, xfs_km_flags_t flags)
- {
- void *ptr;
- trace_kmem_alloc_large(size, flags, _RET_IP_);
- ptr = kmem_alloc(size, flags | KM_MAYFAIL);
- if (ptr)
- return ptr;
- return __kmem_vmalloc(size, flags);
- }
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