diff options
Diffstat (limited to 'fs/erofs/pcpubuf.c')
-rw-r--r-- | fs/erofs/pcpubuf.c | 148 |
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; - } -} |