From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Lameter Subject: [05/17] vunmap: return page array Date: Tue, 18 Sep 2007 20:36:10 -0700 Message-ID: <20070919033641.468440734@sgi.com> References: <20070919033605.785839297@sgi.com> Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org To: Christoph Hellwig , Mel Gorman Return-path: Received: from netops-testserver-4-out.sgi.com ([192.48.171.29]:54926 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751984AbXISDgm (ORCPT ); Tue, 18 Sep 2007 23:36:42 -0400 Cc: David Chinner , Jens Axboe Content-Disposition: inline; filename=vcompound_vunmap_returns_pages Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org Make vunmap return the page array that was used at vmap. This is useful if one has no structures to track the page array but simply stores the virtual address somewhere. The disposition of the page array can be decided upon after vunmap. vfree() may now also be used instead of vunmap which will release the page array after vunmap'ping it. Signed-off-by: Christoph Lameter --- include/linux/vmalloc.h | 2 +- mm/vmalloc.c | 26 ++++++++++++++++---------- 2 files changed, 17 insertions(+), 11 deletions(-) Index: linux-2.6/include/linux/vmalloc.h =================================================================== --- linux-2.6.orig/include/linux/vmalloc.h 2007-09-18 13:22:56.000000000 -0700 +++ linux-2.6/include/linux/vmalloc.h 2007-09-18 13:22:57.000000000 -0700 @@ -49,7 +49,7 @@ extern void vfree(const void *addr); extern void *vmap(struct page **pages, unsigned int count, unsigned long flags, pgprot_t prot); -extern void vunmap(const void *addr); +extern struct page **vunmap(const void *addr); extern int remap_vmalloc_range(struct vm_area_struct *vma, void *addr, unsigned long pgoff); Index: linux-2.6/mm/vmalloc.c =================================================================== --- linux-2.6.orig/mm/vmalloc.c 2007-09-18 13:22:56.000000000 -0700 +++ linux-2.6/mm/vmalloc.c 2007-09-18 13:22:57.000000000 -0700 @@ -356,17 +356,18 @@ struct vm_struct *remove_vm_area(const v return v; } -static void __vunmap(const void *addr, int deallocate_pages) +static struct page **__vunmap(const void *addr, int deallocate_pages) { struct vm_struct *area; + struct page **pages; if (!addr) - return; + return NULL; if ((PAGE_SIZE-1) & (unsigned long)addr) { printk(KERN_ERR "Trying to vfree() bad address (%p)\n", addr); WARN_ON(1); - return; + return NULL; } area = remove_vm_area(addr); @@ -374,29 +375,30 @@ static void __vunmap(const void *addr, i printk(KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n", addr); WARN_ON(1); - return; + return NULL; } + pages = area->pages; debug_check_no_locks_freed(addr, area->size); if (deallocate_pages) { int i; for (i = 0; i < area->nr_pages; i++) { - struct page *page = area->pages[i]; + struct page *page = pages[i]; BUG_ON(!page); __free_page(page); } if (area->flags & VM_VPAGES) - vfree(area->pages); + vfree(pages); else - kfree(area->pages); + kfree(pages); } kfree(area); - return; + return pages; } /** @@ -424,11 +426,13 @@ EXPORT_SYMBOL(vfree); * which was created from the page array passed to vmap(). * * Must not be called in interrupt context. + * + * Returns a pointer to the array of pointers to page structs */ -void vunmap(const void *addr) +struct page **vunmap(const void *addr) { BUG_ON(in_interrupt()); - __vunmap(addr, 0); + return __vunmap(addr, 0); } EXPORT_SYMBOL(vunmap); @@ -453,6 +457,8 @@ void *vmap(struct page **pages, unsigned area = get_vm_area((count << PAGE_SHIFT), flags); if (!area) return NULL; + area->pages = pages; + area->nr_pages = count; if (map_vm_area(area, prot, &pages)) { vunmap(area->addr); return NULL; --