drm/edid: Don't accept any old garbage as a display descriptor

[linux-2.6-microblaze.git] / mm / filemap.c

diff --git a/mm/filemap.c b/mm/filemap.c
index 85b7d08..bf6aa30 100644 (file)
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2329,27 +2329,6 @@ EXPORT_SYMBOL(generic_file_read_iter);
 
 #ifdef CONFIG_MMU
 #define MMAP_LOTSAMISS  (100)
-static struct file *maybe_unlock_mmap_for_io(struct vm_fault *vmf,
-                                            struct file *fpin)
-{
-       int flags = vmf->flags;
-
-       if (fpin)
-               return fpin;
-
-       /*
-        * FAULT_FLAG_RETRY_NOWAIT means we don't want to wait on page locks or
-        * anything, so we only pin the file and drop the mmap_sem if only
-        * FAULT_FLAG_ALLOW_RETRY is set.
-        */
-       if ((flags & (FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_RETRY_NOWAIT)) ==
-           FAULT_FLAG_ALLOW_RETRY) {
-               fpin = get_file(vmf->vma->vm_file);
-               up_read(&vmf->vma->vm_mm->mmap_sem);
-       }
-       return fpin;
-}
-
 /*
  * lock_page_maybe_drop_mmap - lock the page, possibly dropping the mmap_sem
  * @vmf - the vm_fault for this fault.
@@ -3161,6 +3140,27 @@ int pagecache_write_end(struct file *file, struct address_space *mapping,
 }
 EXPORT_SYMBOL(pagecache_write_end);
 
+/*
+ * Warn about a page cache invalidation failure during a direct I/O write.
+ */
+void dio_warn_stale_pagecache(struct file *filp)
+{
+       static DEFINE_RATELIMIT_STATE(_rs, 86400 * HZ, DEFAULT_RATELIMIT_BURST);
+       char pathname[128];
+       struct inode *inode = file_inode(filp);
+       char *path;
+
+       errseq_set(&inode->i_mapping->wb_err, -EIO);
+       if (__ratelimit(&_rs)) {
+               path = file_path(filp, pathname, sizeof(pathname));
+               if (IS_ERR(path))
+                       path = "(unknown)";
+               pr_crit("Page cache invalidation failure on direct I/O.  Possible data corruption due to collision with buffered I/O!\n");
+               pr_crit("File: %s PID: %d Comm: %.20s\n", path, current->pid,
+                       current->comm);
+       }
+}
+
 ssize_t
 generic_file_direct_write(struct kiocb *iocb, struct iov_iter *from)
 {
@@ -3218,11 +3218,15 @@ generic_file_direct_write(struct kiocb *iocb, struct iov_iter *from)
         * Most of the time we do not need this since dio_complete() will do
         * the invalidation for us. However there are some file systems that
         * do not end up with dio_complete() being called, so let's not break
-        * them by removing it completely
+        * them by removing it completely.
+        *
+        * Noticeable example is a blkdev_direct_IO().
+        *
+        * Skip invalidation for async writes or if mapping has no pages.
         */
-       if (mapping->nrpages)
-               invalidate_inode_pages2_range(mapping,
-                                       pos >> PAGE_SHIFT, end);
+       if (written > 0 && mapping->nrpages &&
+           invalidate_inode_pages2_range(mapping, pos >> PAGE_SHIFT, end))
+               dio_warn_stale_pagecache(file);
 
        if (written > 0) {
                pos += written;