ALSA: usb-audio: add support for Akai MPD16

[safe/jmp/linux-2.6] / mm / truncate.c

diff --git a/mm/truncate.c b/mm/truncate.c
index ea132f7..f42675a 100644 (file)
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -9,6 +9,7 @@
 
 #include <linux/kernel.h>
 #include <linux/backing-dev.h>
+#include <linux/gfp.h>
 #include <linux/mm.h>
 #include <linux/swap.h>
 #include <linux/module.h>
@@ -147,6 +148,23 @@ int truncate_inode_page(struct address_space *mapping, struct page *page)
 }
 
 /*
+ * Used to get rid of pages on hardware memory corruption.
+ */
+int generic_error_remove_page(struct address_space *mapping, struct page *page)
+{
+       if (!mapping)
+               return -EINVAL;
+       /*
+        * Only punch for normal data pages for now.
+        * Handling other types like directories would need more auditing.
+        */
+       if (!S_ISREG(mapping->host->i_mode))
+               return -EIO;
+       return truncate_inode_page(mapping, page);
+}
+EXPORT_SYMBOL(generic_error_remove_page);
+
+/*
  * Safely invalidate one page from its pagecache mapping.
  * It only drops clean, unused pages. The page must be locked.
  *
@@ -255,6 +273,7 @@ void truncate_inode_pages_range(struct address_space *mapping,
                        pagevec_release(&pvec);
                        break;
                }
+               mem_cgroup_uncharge_start();
                for (i = 0; i < pagevec_count(&pvec); i++) {
                        struct page *page = pvec.pages[i];
 
@@ -269,6 +288,7 @@ void truncate_inode_pages_range(struct address_space *mapping,
                        unlock_page(page);
                }
                pagevec_release(&pvec);
+               mem_cgroup_uncharge_end();
        }
 }
 EXPORT_SYMBOL(truncate_inode_pages_range);
@@ -310,6 +330,7 @@ unsigned long invalidate_mapping_pages(struct address_space *mapping,
        pagevec_init(&pvec, 0);
        while (next <= end &&
                        pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE)) {
+               mem_cgroup_uncharge_start();
                for (i = 0; i < pagevec_count(&pvec); i++) {
                        struct page *page = pvec.pages[i];
                        pgoff_t index;
@@ -337,6 +358,7 @@ unsigned long invalidate_mapping_pages(struct address_space *mapping,
                                break;
                }
                pagevec_release(&pvec);
+               mem_cgroup_uncharge_end();
                cond_resched();
        }
        return ret;
@@ -411,6 +433,7 @@ int invalidate_inode_pages2_range(struct address_space *mapping,
        while (next <= end && !wrapped &&
                pagevec_lookup(&pvec, mapping, next,
                        min(end - next, (pgoff_t)PAGEVEC_SIZE - 1) + 1)) {
+               mem_cgroup_uncharge_start();
                for (i = 0; i < pagevec_count(&pvec); i++) {
                        struct page *page = pvec.pages[i];
                        pgoff_t page_index;
@@ -460,6 +483,7 @@ int invalidate_inode_pages2_range(struct address_space *mapping,
                        unlock_page(page);
                }
                pagevec_release(&pvec);
+               mem_cgroup_uncharge_end();
                cond_resched();
        }
        return ret;
@@ -473,10 +497,72 @@ EXPORT_SYMBOL_GPL(invalidate_inode_pages2_range);
  * Any pages which are found to be mapped into pagetables are unmapped prior to
  * invalidation.
  *
- * Returns -EIO if any pages could not be invalidated.
+ * Returns -EBUSY 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);
+
+/**
+ * truncate_pagecache - unmap and remove pagecache that has been truncated
+ * @inode: inode
+ * @old: old file offset
+ * @new: new file offset
+ *
+ * inode's new i_size must already be written before truncate_pagecache
+ * is called.
+ *
+ * This function should typically be called before the filesystem
+ * releases resources associated with the freed range (eg. deallocates
+ * blocks). This way, pagecache will always stay logically coherent
+ * with on-disk format, and the filesystem would not have to deal with
+ * situations such as writepage being called for a page that has already
+ * had its underlying blocks deallocated.
+ */
+void truncate_pagecache(struct inode *inode, loff_t old, loff_t new)
+{
+       struct address_space *mapping = inode->i_mapping;
+
+       /*
+        * unmap_mapping_range is called twice, first simply for
+        * efficiency so that truncate_inode_pages does fewer
+        * single-page unmaps.  However after this first call, and
+        * before truncate_inode_pages finishes, it is possible for
+        * private pages to be COWed, which remain after
+        * truncate_inode_pages finishes, hence the second
+        * unmap_mapping_range call must be made for correctness.
+        */
+       unmap_mapping_range(mapping, new + PAGE_SIZE - 1, 0, 1);
+       truncate_inode_pages(mapping, new);
+       unmap_mapping_range(mapping, new + PAGE_SIZE - 1, 0, 1);
+}
+EXPORT_SYMBOL(truncate_pagecache);
+
+/**
+ * vmtruncate - unmap mappings "freed" by truncate() syscall
+ * @inode: inode of the file used
+ * @offset: file offset to start truncating
+ *
+ * NOTE! We have to be ready to update the memory sharing
+ * between the file and the memory map for a potential last
+ * incomplete page.  Ugly, but necessary.
+ */
+int vmtruncate(struct inode *inode, loff_t offset)
+{
+       loff_t oldsize;
+       int error;
+
+       error = inode_newsize_ok(inode, offset);
+       if (error)
+               return error;
+       oldsize = inode->i_size;
+       i_size_write(inode, offset);
+       truncate_pagecache(inode, oldsize, offset);
+       if (inode->i_op->truncate)
+               inode->i_op->truncate(inode);
+
+       return error;
+}
+EXPORT_SYMBOL(vmtruncate);