1 files changed, 45 insertions, 156 deletions

diff --git a/fs/buffer.c b/fs/buffer.c
index 891e1c78e4f1..f5f8b15a6e40 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -166,151 +166,6 @@ void end_buffer_write_sync(struct buffer_head *bh, int uptodate)
 }
 
 /*
- * Write out and wait upon all the dirty data associated with a block
- * device via its mapping.  Does not take the superblock lock.
- */
-int sync_blockdev(struct block_device *bdev)
-{
-        int ret = 0;
-
-        if (bdev)
-                ret = filemap_write_and_wait(bdev->bd_inode->i_mapping);
-        return ret;
-}
-EXPORT_SYMBOL(sync_blockdev);
-
-/*
- * Write out and wait upon all dirty data associated with this
- * device.   Filesystem data as well as the underlying block
- * device.  Takes the superblock lock.
- */
-int fsync_bdev(struct block_device *bdev)
-{
-        struct super_block *sb = get_super(bdev);
-        if (sb) {
-                int res = fsync_super(sb);
-                drop_super(sb);
-                return res;
-        }
-        return sync_blockdev(bdev);
-}
-
-/**
- * freeze_bdev  --  lock a filesystem and force it into a consistent state
- * @bdev:       blockdevice to lock
- *
- * This takes the block device bd_mount_sem to make sure no new mounts
- * happen on bdev until thaw_bdev() is called.
- * If a superblock is found on this device, we take the s_umount semaphore
- * on it to make sure nobody unmounts until the snapshot creation is done.
- * The reference counter (bd_fsfreeze_count) guarantees that only the last
- * unfreeze process can unfreeze the frozen filesystem actually when multiple
- * freeze requests arrive simultaneously. It counts up in freeze_bdev() and
- * count down in thaw_bdev(). When it becomes 0, thaw_bdev() will unfreeze
- * actually.
- */
-struct super_block *freeze_bdev(struct block_device *bdev)
-{
-        struct super_block *sb;
-        int error = 0;
-
-        mutex_lock(&bdev->bd_fsfreeze_mutex);
-        if (bdev->bd_fsfreeze_count > 0) {
-                bdev->bd_fsfreeze_count++;
-                sb = get_super(bdev);
-                mutex_unlock(&bdev->bd_fsfreeze_mutex);
-                return sb;
-        }
-        bdev->bd_fsfreeze_count++;
-
-        down(&bdev->bd_mount_sem);
-        sb = get_super(bdev);
-        if (sb && !(sb->s_flags & MS_RDONLY)) {
-                sb->s_frozen = SB_FREEZE_WRITE;
-                smp_wmb();
-
-                __fsync_super(sb);
-
-                sb->s_frozen = SB_FREEZE_TRANS;
-                smp_wmb();
-
-                sync_blockdev(sb->s_bdev);
-
-                if (sb->s_op->freeze_fs) {
-                        error = sb->s_op->freeze_fs(sb);
-                        if (error) {
-                                printk(KERN_ERR
-                                        "VFS:Filesystem freeze failed\n");
-                                sb->s_frozen = SB_UNFROZEN;
-                                drop_super(sb);
-                                up(&bdev->bd_mount_sem);
-                                bdev->bd_fsfreeze_count--;
-                                mutex_unlock(&bdev->bd_fsfreeze_mutex);
-                                return ERR_PTR(error);
-                        }
-                }
-        }
-
-        sync_blockdev(bdev);
-        mutex_unlock(&bdev->bd_fsfreeze_mutex);
-
-        return sb;      /* thaw_bdev releases s->s_umount and bd_mount_sem */
-}
-EXPORT_SYMBOL(freeze_bdev);
-
-/**
- * thaw_bdev  -- unlock filesystem
- * @bdev:       blockdevice to unlock
- * @sb:         associated superblock
- *
- * Unlocks the filesystem and marks it writeable again after freeze_bdev().
- */
-int thaw_bdev(struct block_device *bdev, struct super_block *sb)
-{
-        int error = 0;
-
-        mutex_lock(&bdev->bd_fsfreeze_mutex);
-        if (!bdev->bd_fsfreeze_count) {
-                mutex_unlock(&bdev->bd_fsfreeze_mutex);
-                return -EINVAL;
-        }
-
-        bdev->bd_fsfreeze_count--;
-        if (bdev->bd_fsfreeze_count > 0) {
-                if (sb)
-                        drop_super(sb);
-                mutex_unlock(&bdev->bd_fsfreeze_mutex);
-                return 0;
-        }
-
-        if (sb) {
-                BUG_ON(sb->s_bdev != bdev);
-                if (!(sb->s_flags & MS_RDONLY)) {
-                        if (sb->s_op->unfreeze_fs) {
-                                error = sb->s_op->unfreeze_fs(sb);
-                                if (error) {
-                                        printk(KERN_ERR
-                                                "VFS:Filesystem thaw failed\n");
-                                        sb->s_frozen = SB_FREEZE_TRANS;
-                                        bdev->bd_fsfreeze_count++;
-                                        mutex_unlock(&bdev->bd_fsfreeze_mutex);
-                                        return error;
-                                }
-                        }
-                        sb->s_frozen = SB_UNFROZEN;
-                        smp_wmb();
-                        wake_up(&sb->s_wait_unfrozen);
-                }
-                drop_super(sb);
-        }
-
-        up(&bdev->bd_mount_sem);
-        mutex_unlock(&bdev->bd_fsfreeze_mutex);
-        return 0;
-}
-EXPORT_SYMBOL(thaw_bdev);
-
-/*
  * Various filesystems appear to want __find_get_block to be non-blocking.
  * But it's the page lock which protects the buffers.  To get around this,
  * we get exclusion from try_to_free_buffers with the blockdev mapping's
@@ -435,7 +290,7 @@ static void free_more_memory(void)
                                                 &zone);
                 if (zone)
                         try_to_free_pages(node_zonelist(nid, GFP_NOFS), 0,
-                                                GFP_NOFS);
+                                                GFP_NOFS, NULL);
         }
 }
 
@@ -692,6 +547,39 @@ repeat:
         return err;
 }
 
+void do_thaw_all(unsigned long unused)
+{
+        struct super_block *sb;
+        char b[BDEVNAME_SIZE];
+
+        spin_lock(&sb_lock);
+restart:
+        list_for_each_entry(sb, &super_blocks, s_list) {
+                sb->s_count++;
+                spin_unlock(&sb_lock);
+                down_read(&sb->s_umount);
+                while (sb->s_bdev && !thaw_bdev(sb->s_bdev, sb))
+                        printk(KERN_WARNING "Emergency Thaw on %s\n",
+                               bdevname(sb->s_bdev, b));
+                up_read(&sb->s_umount);
+                spin_lock(&sb_lock);
+                if (__put_super_and_need_restart(sb))
+                        goto restart;
+        }
+        spin_unlock(&sb_lock);
+        printk(KERN_WARNING "Emergency Thaw complete\n");
+}
+
+/**
+ * emergency_thaw_all -- forcibly thaw every frozen filesystem
+ *
+ * Used for emergency unfreeze of all filesystems via SysRq
+ */
+void emergency_thaw_all(void)
+{
+        pdflush_operation(do_thaw_all, 0);
+}
+
 /**
  * sync_mapping_buffers - write out & wait upon a mapping's "associated" buffers
  * @mapping: the mapping which wants those buffers written
@@ -766,14 +654,7 @@ static void __set_page_dirty(struct page *page,
         spin_lock_irq(&mapping->tree_lock);
         if (page->mapping) {    /* Race with truncate? */
                 WARN_ON_ONCE(warn && !PageUptodate(page));
-
-                if (mapping_cap_account_dirty(mapping)) {
-                        __inc_zone_page_state(page, NR_FILE_DIRTY);
-                        __inc_bdi_stat(mapping->backing_dev_info,
-                                        BDI_RECLAIMABLE);
-                        task_dirty_inc(current);
-                        task_io_account_write(PAGE_CACHE_SIZE);
-                }
+                account_page_dirtied(page, mapping);
                 radix_tree_tag_set(&mapping->page_tree,
                                 page_index(page), PAGECACHE_TAG_DIRTY);
         }
@@ -2465,13 +2346,14 @@ int block_commit_write(struct page *page, unsigned from, unsigned to)
  * unlock the page.
  */
 int
-block_page_mkwrite(struct vm_area_struct *vma, struct page *page,
+block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
                    get_block_t get_block)
 {
+        struct page *page = vmf->page;
         struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
         unsigned long end;
         loff_t size;
-        int ret = -EINVAL;
+        int ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
 
         lock_page(page);
         size = i_size_read(inode);
@@ -2491,6 +2373,13 @@ block_page_mkwrite(struct vm_area_struct *vma, struct page *page,
         if (!ret)
                 ret = block_commit_write(page, 0, end);
 
+        if (unlikely(ret)) {
+                if (ret == -ENOMEM)
+                        ret = VM_FAULT_OOM;
+                else /* -ENOSPC, -EIO, etc */
+                        ret = VM_FAULT_SIGBUS;
+        }
+
 out_unlock:
         unlock_page(page);
         return ret;