summaryrefslogtreecommitdiffstats
path: root/fs/erofs/pcpubuf.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/erofs/pcpubuf.c')
-rw-r--r--fs/erofs/pcpubuf.c148
1 files changed, 0 insertions, 148 deletions
diff --git a/fs/erofs/pcpubuf.c b/fs/erofs/pcpubuf.c
deleted file mode 100644
index c7a4b1d770..0000000000
--- a/fs/erofs/pcpubuf.c
+++ /dev/null
@@ -1,148 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * Copyright (C) Gao Xiang <xiang@kernel.org>
- *
- * For low-latency decompression algorithms (e.g. lz4), reserve consecutive
- * per-CPU virtual memory (in pages) in advance to store such inplace I/O
- * data if inplace decompression is failed (due to unmet inplace margin for
- * example).
- */
-#include "internal.h"
-
-struct erofs_pcpubuf {
- raw_spinlock_t lock;
- void *ptr;
- struct page **pages;
- unsigned int nrpages;
-};
-
-static DEFINE_PER_CPU(struct erofs_pcpubuf, erofs_pcb);
-
-void *erofs_get_pcpubuf(unsigned int requiredpages)
- __acquires(pcb->lock)
-{
- struct erofs_pcpubuf *pcb = &get_cpu_var(erofs_pcb);
-
- raw_spin_lock(&pcb->lock);
- /* check if the per-CPU buffer is too small */
- if (requiredpages > pcb->nrpages) {
- raw_spin_unlock(&pcb->lock);
- put_cpu_var(erofs_pcb);
- /* (for sparse checker) pretend pcb->lock is still taken */
- __acquire(pcb->lock);
- return NULL;
- }
- return pcb->ptr;
-}
-
-void erofs_put_pcpubuf(void *ptr) __releases(pcb->lock)
-{
- struct erofs_pcpubuf *pcb = &per_cpu(erofs_pcb, smp_processor_id());
-
- DBG_BUGON(pcb->ptr != ptr);
- raw_spin_unlock(&pcb->lock);
- put_cpu_var(erofs_pcb);
-}
-
-/* the next step: support per-CPU page buffers hotplug */
-int erofs_pcpubuf_growsize(unsigned int nrpages)
-{
- static DEFINE_MUTEX(pcb_resize_mutex);
- static unsigned int pcb_nrpages;
- struct page *pagepool = NULL;
- int delta, cpu, ret, i;
-
- mutex_lock(&pcb_resize_mutex);
- delta = nrpages - pcb_nrpages;
- ret = 0;
- /* avoid shrinking pcpubuf, since no idea how many fses rely on */
- if (delta <= 0)
- goto out;
-
- for_each_possible_cpu(cpu) {
- struct erofs_pcpubuf *pcb = &per_cpu(erofs_pcb, cpu);
- struct page **pages, **oldpages;
- void *ptr, *old_ptr;
-
- pages = kmalloc_array(nrpages, sizeof(*pages), GFP_KERNEL);
- if (!pages) {
- ret = -ENOMEM;
- break;
- }
-
- for (i = 0; i < nrpages; ++i) {
- pages[i] = erofs_allocpage(&pagepool, GFP_KERNEL);
- if (!pages[i]) {
- ret = -ENOMEM;
- oldpages = pages;
- goto free_pagearray;
- }
- }
- ptr = vmap(pages, nrpages, VM_MAP, PAGE_KERNEL);
- if (!ptr) {
- ret = -ENOMEM;
- oldpages = pages;
- goto free_pagearray;
- }
- raw_spin_lock(&pcb->lock);
- old_ptr = pcb->ptr;
- pcb->ptr = ptr;
- oldpages = pcb->pages;
- pcb->pages = pages;
- i = pcb->nrpages;
- pcb->nrpages = nrpages;
- raw_spin_unlock(&pcb->lock);
-
- if (!oldpages) {
- DBG_BUGON(old_ptr);
- continue;
- }
-
- if (old_ptr)
- vunmap(old_ptr);
-free_pagearray:
- while (i)
- erofs_pagepool_add(&pagepool, oldpages[--i]);
- kfree(oldpages);
- if (ret)
- break;
- }
- pcb_nrpages = nrpages;
- erofs_release_pages(&pagepool);
-out:
- mutex_unlock(&pcb_resize_mutex);
- return ret;
-}
-
-void __init erofs_pcpubuf_init(void)
-{
- int cpu;
-
- for_each_possible_cpu(cpu) {
- struct erofs_pcpubuf *pcb = &per_cpu(erofs_pcb, cpu);
-
- raw_spin_lock_init(&pcb->lock);
- }
-}
-
-void erofs_pcpubuf_exit(void)
-{
- int cpu, i;
-
- for_each_possible_cpu(cpu) {
- struct erofs_pcpubuf *pcb = &per_cpu(erofs_pcb, cpu);
-
- if (pcb->ptr) {
- vunmap(pcb->ptr);
- pcb->ptr = NULL;
- }
- if (!pcb->pages)
- continue;
-
- for (i = 0; i < pcb->nrpages; ++i)
- if (pcb->pages[i])
- put_page(pcb->pages[i]);
- kfree(pcb->pages);
- pcb->pages = NULL;
- }
-}