Btrfs: fix more ESTALE problems with NFS

[pandora-kernel.git] / fs / fs-writeback.c

diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 5581122..1e23c33 100644 (file)
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -72,22 +72,11 @@ int writeback_in_progress(struct backing_dev_info *bdi)
 static inline struct backing_dev_info *inode_to_bdi(struct inode *inode)
 {
        struct super_block *sb = inode->i_sb;
-       struct backing_dev_info *bdi = inode->i_mapping->backing_dev_info;
 
-       /*
-        * For inodes on standard filesystems, we use superblock's bdi. For
-        * inodes on virtual filesystems, we want to use inode mapping's bdi
-        * because they can possibly point to something useful (think about
-        * block_dev filesystem).
-        */
-       if (sb->s_bdi && sb->s_bdi != &noop_backing_dev_info) {
-               /* Some device inodes could play dirty tricks. Catch them... */
-               WARN(bdi != sb->s_bdi && bdi_cap_writeback_dirty(bdi),
-                       "Dirtiable inode bdi %s != sb bdi %s\n",
-                       bdi->name, sb->s_bdi->name);
-               return sb->s_bdi;
-       }
-       return bdi;
+       if (strcmp(sb->s_type->name, "bdev") == 0)
+               return inode->i_mapping->backing_dev_info;
+
+       return sb->s_bdi;
 }
 
 static void bdi_queue_work(struct backing_dev_info *bdi,
@@ -1080,33 +1069,44 @@ static void wait_sb_inodes(struct super_block *sb)
 }
 
 /**
- * writeback_inodes_sb -       writeback dirty inodes from given super_block
+ * writeback_inodes_sb_nr -    writeback dirty inodes from given super_block
  * @sb: the superblock
+ * @nr: the number of pages to write
  *
  * Start writeback on some inodes on this super_block. No guarantees are made
  * on how many (if any) will be written, and this function does not wait
- * for IO completion of submitted IO. The number of pages submitted is
- * returned.
+ * for IO completion of submitted IO.
  */
-void writeback_inodes_sb(struct super_block *sb)
+void writeback_inodes_sb_nr(struct super_block *sb, unsigned long nr)
 {
-       unsigned long nr_dirty = global_page_state(NR_FILE_DIRTY);
-       unsigned long nr_unstable = global_page_state(NR_UNSTABLE_NFS);
        DECLARE_COMPLETION_ONSTACK(done);
        struct wb_writeback_work work = {
                .sb             = sb,
                .sync_mode      = WB_SYNC_NONE,
                .done           = &done,
+               .nr_pages       = nr,
        };
 
        WARN_ON(!rwsem_is_locked(&sb->s_umount));
-
-       work.nr_pages = nr_dirty + nr_unstable +
-                       (inodes_stat.nr_inodes - inodes_stat.nr_unused);
-
        bdi_queue_work(sb->s_bdi, &work);
        wait_for_completion(&done);
 }
+EXPORT_SYMBOL(writeback_inodes_sb_nr);
+
+/**
+ * writeback_inodes_sb -       writeback dirty inodes from given super_block
+ * @sb: the superblock
+ *
+ * Start writeback on some inodes on this super_block. No guarantees are made
+ * on how many (if any) will be written, and this function does not wait
+ * for IO completion of submitted IO.
+ */
+void writeback_inodes_sb(struct super_block *sb)
+{
+       return writeback_inodes_sb_nr(sb, global_page_state(NR_FILE_DIRTY) +
+                             global_page_state(NR_UNSTABLE_NFS) +
+                             (inodes_stat.nr_inodes - inodes_stat.nr_unused));
+}
 EXPORT_SYMBOL(writeback_inodes_sb);
 
 /**
@@ -1128,6 +1128,27 @@ int writeback_inodes_sb_if_idle(struct super_block *sb)
 }
 EXPORT_SYMBOL(writeback_inodes_sb_if_idle);
 
+/**
+ * writeback_inodes_sb_if_idle -       start writeback if none underway
+ * @sb: the superblock
+ * @nr: the number of pages to write
+ *
+ * Invoke writeback_inodes_sb if no writeback is currently underway.
+ * Returns 1 if writeback was started, 0 if not.
+ */
+int writeback_inodes_sb_nr_if_idle(struct super_block *sb,
+                                  unsigned long nr)
+{
+       if (!writeback_in_progress(sb->s_bdi)) {
+               down_read(&sb->s_umount);
+               writeback_inodes_sb_nr(sb, nr);
+               up_read(&sb->s_umount);
+               return 1;
+       } else
+               return 0;
+}
+EXPORT_SYMBOL(writeback_inodes_sb_nr_if_idle);
+
 /**
  * sync_inodes_sb      -       sync sb inode pages
  * @sb: the superblock