mm: bugfix: set current->reclaim_state to NULL while returning from kswapd()
[linux-2.6.git] / mm / filemap_xip.c
index 5b9ec47..a4eb311 100644 (file)
 
 #include <linux/fs.h>
 #include <linux/pagemap.h>
-#include <linux/module.h>
+#include <linux/export.h>
 #include <linux/uio.h>
 #include <linux/rmap.h>
 #include <linux/mmu_notifier.h>
 #include <linux/sched.h>
 #include <linux/seqlock.h>
 #include <linux/mutex.h>
+#include <linux/gfp.h>
 #include <asm/tlbflush.h>
 #include <asm/io.h>
 
@@ -89,8 +90,8 @@ do_xip_mapping_read(struct address_space *mapping,
                        }
                }
                nr = nr - offset;
-               if (nr > len)
-                       nr = len;
+               if (nr > len - copied)
+                       nr = len - copied;
 
                error = mapping->a_ops->get_xip_mem(mapping, index, 0,
                                                        &xip_mem, &xip_pfn);
@@ -182,7 +183,7 @@ __xip_unmap (struct address_space * mapping,
                return;
 
 retry:
-       spin_lock(&mapping->i_mmap_lock);
+       mutex_lock(&mapping->i_mmap_mutex);
        vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, pgoff, pgoff) {
                mm = vma->vm_mm;
                address = vma->vm_start +
@@ -193,14 +194,14 @@ retry:
                        /* Nuke the page table entry. */
                        flush_cache_page(vma, address, pte_pfn(*pte));
                        pteval = ptep_clear_flush_notify(vma, address, pte);
-                       page_remove_rmap(page, vma);
-                       dec_mm_counter(mm, file_rss);
+                       page_remove_rmap(page);
+                       dec_mm_counter(mm, MM_FILEPAGES);
                        BUG_ON(pte_dirty(pteval));
                        pte_unmap_unlock(pte, ptl);
                        page_cache_release(page);
                }
        }
-       spin_unlock(&mapping->i_mmap_lock);
+       mutex_unlock(&mapping->i_mmap_mutex);
 
        if (locked) {
                mutex_unlock(&xip_sparse_mutex);
@@ -248,20 +249,26 @@ again:
                int err;
 
                /* maybe shared writable, allocate new block */
+               mutex_lock(&xip_sparse_mutex);
                error = mapping->a_ops->get_xip_mem(mapping, vmf->pgoff, 1,
                                                        &xip_mem, &xip_pfn);
+               mutex_unlock(&xip_sparse_mutex);
                if (error)
                        return VM_FAULT_SIGBUS;
                /* unmap sparse mappings at pgoff from all other vmas */
                __xip_unmap(mapping, vmf->pgoff);
 
 found:
-               printk("%s insert %lx@%lx\n", current->comm, (unsigned long)vmf->virtual_address, xip_pfn);
                err = vm_insert_mixed(vma, (unsigned long)vmf->virtual_address,
                                                        xip_pfn);
                if (err == -ENOMEM)
                        return VM_FAULT_OOM;
-               BUG_ON(err);
+               /*
+                * err == -EBUSY is fine, we've raced against another thread
+                * that faulted-in the same page
+                */
+               if (err != -EBUSY)
+                       BUG_ON(err);
                return VM_FAULT_NOPAGE;
        } else {
                int err, ret = VM_FAULT_OOM;
@@ -295,7 +302,7 @@ out:
        }
 }
 
-static struct vm_operations_struct xip_file_vm_ops = {
+static const struct vm_operations_struct xip_file_vm_ops = {
        .fault  = xip_file_fault,
 };
 
@@ -340,8 +347,10 @@ __xip_file_write(struct file *filp, const char __user *buf,
                                                &xip_mem, &xip_pfn);
                if (status == -ENODATA) {
                        /* we allocate a new page unmap it */
+                       mutex_lock(&xip_sparse_mutex);
                        status = a_ops->get_xip_mem(mapping, index, 1,
                                                        &xip_mem, &xip_pfn);
+                       mutex_unlock(&xip_sparse_mutex);
                        if (!status)
                                /* unmap page at pgoff from all other vmas */
                                __xip_unmap(mapping, index);