Messages in this thread Patch in this message | | | Date | Thu, 20 Sep 2001 01:49:05 +0200 | From | Andrea Arcangeli <> | Subject | Re: pre12 VM doubts and patch |
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On Thu, Sep 20, 2001 at 01:31:53AM +0200, Andrea Arcangeli wrote: > --- 2.4.10pre11aa1/mm/vmscan.c.~1~ Tue Sep 18 21:23:49 2001 > +++ 2.4.10pre11aa1/mm/vmscan.c Thu Sep 20 01:29:58 2001 > @@ -415,7 +415,10 @@ > spin_unlock(&pagemap_lru_lock); > > ClearPageDirty(page); > + > + page_cache_get(page); > writepage(page); > + page_cache_release(page); > > spin_lock(&pagemap_lru_lock); > continue;
then in turn we can backout this bit (patch -R)
diff -urN 2.4.10pre11/mm/page_io.c 2.4.10pre12/mm/page_io.c --- 2.4.10pre11/mm/page_io.c Tue May 1 19:35:33 2001 +++ 2.4.10pre12/mm/page_io.c Thu Sep 20 01:44:20 2001 @@ -78,7 +78,15 @@ if (!wait) { SetPageDecrAfter(page); atomic_inc(&nr_async_pages); - } + } else + /* + * Must hold a reference until after wait_on_page() + * returned or it could be freed by the VM after + * I/O is completed and the page is been unlocked. + * The asynchronous path is fine since it never + * references the page after brw_page(). + */ + page_cache_get(page); /* block_size == PAGE_SIZE/zones_used */ brw_page(rw, page, dev, zones, block_size); @@ -94,6 +102,7 @@ /* This shouldn't happen, but check to be sure. */ if (page_count(page) == 0) printk(KERN_ERR "rw_swap_page: page unused while waiting!\n"); + page_cache_release(page); return 1; } Andrea - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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