Fedora kernel-2.6.17-1.2142_FC4 patched with stable patch-2.6.17.4-vs2.0.2-rc26.diff
[linux-2.6.git] / mm / truncate.c
index 9645008..993844f 100644 (file)
 #include <linux/pagemap.h>
 #include <linux/pagevec.h>
 #include <linux/buffer_head.h> /* grr. try_to_release_page,
-                                  block_invalidatepage */
+                                  do_invalidatepage */
 
 
-static int do_invalidatepage(struct page *page, unsigned long offset)
-{
-       int (*invalidatepage)(struct page *, unsigned long);
-       invalidatepage = page->mapping->a_ops->invalidatepage;
-       if (invalidatepage == NULL)
-               invalidatepage = block_invalidatepage;
-       return (*invalidatepage)(page, offset);
-}
-
 static inline void truncate_partial_page(struct page *page, unsigned partial)
 {
        memclear_highpage_flush(page, partial, PAGE_CACHE_SIZE-partial);
@@ -76,27 +67,30 @@ invalidate_complete_page(struct address_space *mapping, struct page *page)
        if (PagePrivate(page) && !try_to_release_page(page, 0))
                return 0;
 
-       spin_lock_irq(&mapping->tree_lock);
+       write_lock_irq(&mapping->tree_lock);
        if (PageDirty(page)) {
-               spin_unlock_irq(&mapping->tree_lock);
+               write_unlock_irq(&mapping->tree_lock);
                return 0;
        }
 
        BUG_ON(PagePrivate(page));
        __remove_from_page_cache(page);
-       spin_unlock_irq(&mapping->tree_lock);
+       write_unlock_irq(&mapping->tree_lock);
        ClearPageUptodate(page);
        page_cache_release(page);       /* pagecache ref */
        return 1;
 }
 
 /**
- * truncate_inode_pages - truncate *all* the pages from an offset
+ * truncate_inode_pages - truncate range of pages specified by start and
+ * end byte offsets
  * @mapping: mapping to truncate
  * @lstart: offset from which to truncate
+ * @lend: offset to which to truncate
  *
- * Truncate the page cache at a set offset, removing the pages that are beyond
- * that offset (and zeroing out partial pages).
+ * Truncate the page cache, removing the pages that are between
+ * specified offsets (and zeroing out partial page
+ * (if lstart is not page aligned)).
  *
  * Truncate takes two passes - the first pass is nonblocking.  It will not
  * block on page locks and it will not block on writeback.  The second pass
@@ -110,12 +104,12 @@ invalidate_complete_page(struct address_space *mapping, struct page *page)
  * We pass down the cache-hot hint to the page freeing code.  Even if the
  * mapping is large, it is probably the case that the final pages are the most
  * recently touched, and freeing happens in ascending file offset order.
- *
- * Called under (and serialised by) inode->i_sem.
  */
-void truncate_inode_pages(struct address_space *mapping, loff_t lstart)
+void truncate_inode_pages_range(struct address_space *mapping,
+                               loff_t lstart, loff_t lend)
 {
        const pgoff_t start = (lstart + PAGE_CACHE_SIZE-1) >> PAGE_CACHE_SHIFT;
+       pgoff_t end;
        const unsigned partial = lstart & (PAGE_CACHE_SIZE - 1);
        struct pagevec pvec;
        pgoff_t next;
@@ -124,13 +118,22 @@ void truncate_inode_pages(struct address_space *mapping, loff_t lstart)
        if (mapping->nrpages == 0)
                return;
 
+       BUG_ON((lend & (PAGE_CACHE_SIZE - 1)) != (PAGE_CACHE_SIZE - 1));
+       end = (lend >> PAGE_CACHE_SHIFT);
+
        pagevec_init(&pvec, 0);
        next = start;
-       while (pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE)) {
+       while (next <= end &&
+              pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE)) {
                for (i = 0; i < pagevec_count(&pvec); i++) {
                        struct page *page = pvec.pages[i];
                        pgoff_t page_index = page->index;
 
+                       if (page_index > end) {
+                               next = page_index;
+                               break;
+                       }
+
                        if (page_index > next)
                                next = page_index;
                        next++;
@@ -166,9 +169,15 @@ void truncate_inode_pages(struct address_space *mapping, loff_t lstart)
                        next = start;
                        continue;
                }
+               if (pvec.pages[0]->index > end) {
+                       pagevec_release(&pvec);
+                       break;
+               }
                for (i = 0; i < pagevec_count(&pvec); i++) {
                        struct page *page = pvec.pages[i];
 
+                       if (page->index > end)
+                               break;
                        lock_page(page);
                        wait_on_page_writeback(page);
                        if (page->index > next)
@@ -180,7 +189,19 @@ void truncate_inode_pages(struct address_space *mapping, loff_t lstart)
                pagevec_release(&pvec);
        }
 }
+EXPORT_SYMBOL(truncate_inode_pages_range);
 
+/**
+ * truncate_inode_pages - truncate *all* the pages from an offset
+ * @mapping: mapping to truncate
+ * @lstart: offset from which to truncate
+ *
+ * Called under (and serialised by) inode->i_mutex.
+ */
+void truncate_inode_pages(struct address_space *mapping, loff_t lstart)
+{
+       truncate_inode_pages_range(mapping, lstart, (loff_t)-1);
+}
 EXPORT_SYMBOL(truncate_inode_pages);
 
 /**
@@ -228,11 +249,12 @@ unlock:
                                break;
                }
                pagevec_release(&pvec);
-               cond_resched();
        }
        return ret;
 }
 
+EXPORT_SYMBOL_GPL(invalidate_mapping_pages);
+
 unsigned long invalidate_inode_pages(struct address_space *mapping)
 {
        return invalidate_mapping_pages(mapping, 0, ~0UL);
@@ -241,54 +263,68 @@ unsigned long invalidate_inode_pages(struct address_space *mapping)
 EXPORT_SYMBOL(invalidate_inode_pages);
 
 /**
- * invalidate_inode_pages2 - remove all pages from an address_space
- * @mapping - the address_space
+ * invalidate_inode_pages2_range - remove range of pages from an address_space
+ * @mapping: the address_space
+ * @start: the page offset 'from' which to invalidate
+ * @end: the page offset 'to' which to invalidate (inclusive)
  *
  * Any pages which are found to be mapped into pagetables are unmapped prior to
  * invalidation.
  *
  * Returns -EIO if any pages could not be invalidated.
  */
-int invalidate_inode_pages2(struct address_space *mapping)
+int invalidate_inode_pages2_range(struct address_space *mapping,
+                                 pgoff_t start, pgoff_t end)
 {
        struct pagevec pvec;
-       pgoff_t next = 0;
+       pgoff_t next;
        int i;
        int ret = 0;
-       int did_full_unmap = 0;
+       int did_range_unmap = 0;
+       int wrapped = 0;
 
        pagevec_init(&pvec, 0);
-       while (!ret && pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE)) {
+       next = start;
+       while (next <= end && !ret && !wrapped &&
+               pagevec_lookup(&pvec, mapping, next,
+                       min(end - next, (pgoff_t)PAGEVEC_SIZE - 1) + 1)) {
                for (i = 0; !ret && i < pagevec_count(&pvec); i++) {
                        struct page *page = pvec.pages[i];
+                       pgoff_t page_index;
                        int was_dirty;
 
                        lock_page(page);
-                       if (page->mapping != mapping) { /* truncate race? */
+                       if (page->mapping != mapping) {
                                unlock_page(page);
                                continue;
                        }
+                       page_index = page->index;
+                       next = page_index + 1;
+                       if (next == 0)
+                               wrapped = 1;
+                       if (page_index > end) {
+                               unlock_page(page);
+                               break;
+                       }
                        wait_on_page_writeback(page);
-                       next = page->index + 1;
                        while (page_mapped(page)) {
-                               if (!did_full_unmap) {
+                               if (!did_range_unmap) {
                                        /*
                                         * Zap the rest of the file in one hit.
-                                        * FIXME: invalidate_inode_pages2()
-                                        * should take start/end offsets.
                                         */
                                        unmap_mapping_range(mapping,
-                                               page->index << PAGE_CACHE_SHIFT,
-                                               -1, 0);
-                                       did_full_unmap = 1;
+                                          (loff_t)page_index<<PAGE_CACHE_SHIFT,
+                                          (loff_t)(end - page_index + 1)
+                                                       << PAGE_CACHE_SHIFT,
+                                           0);
+                                       did_range_unmap = 1;
                                } else {
                                        /*
                                         * Just zap this page
                                         */
                                        unmap_mapping_range(mapping,
-                                         page->index << PAGE_CACHE_SHIFT,
-                                         (page->index << PAGE_CACHE_SHIFT)+1,
-                                         0);
+                                         (loff_t)page_index<<PAGE_CACHE_SHIFT,
+                                         PAGE_CACHE_SIZE, 0);
                                }
                        }
                        was_dirty = test_clear_page_dirty(page);
@@ -304,4 +340,19 @@ int invalidate_inode_pages2(struct address_space *mapping)
        }
        return ret;
 }
+EXPORT_SYMBOL_GPL(invalidate_inode_pages2_range);
+
+/**
+ * invalidate_inode_pages2 - remove all pages from an address_space
+ * @mapping: the address_space
+ *
+ * Any pages which are found to be mapped into pagetables are unmapped prior to
+ * invalidation.
+ *
+ * Returns -EIO if any pages could not be invalidated.
+ */
+int invalidate_inode_pages2(struct address_space *mapping)
+{
+       return invalidate_inode_pages2_range(mapping, 0, -1);
+}
 EXPORT_SYMBOL_GPL(invalidate_inode_pages2);