1 files changed, 45 insertions, 88 deletions

diff --git a/fs/buffer.c b/fs/buffer.c
index c9c266db0624..50efa339e051 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -275,6 +275,7 @@ void invalidate_bdev(struct block_device *bdev)
                 return;
 
         invalidate_bh_lrus();
+        lru_add_drain_all();    /* make sure all lru add caches are flushed */
         invalidate_mapping_pages(mapping, 0, -1);
 }
 EXPORT_SYMBOL(invalidate_bdev);
@@ -560,26 +561,17 @@ repeat:
         return err;
 }
 
-static void do_thaw_all(struct work_struct *work)
+static void do_thaw_one(struct super_block *sb, void *unused)
 {
-        struct super_block *sb;
         char b[BDEVNAME_SIZE];
+        while (sb->s_bdev && !thaw_bdev(sb->s_bdev, sb))
+                printk(KERN_WARNING "Emergency Thaw on %s\n",
+                       bdevname(sb->s_bdev, b));
+}
 
-        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);
+static void do_thaw_all(struct work_struct *work)
+{
+        iterate_supers(do_thaw_one, NULL);
         kfree(work);
         printk(KERN_WARNING "Emergency Thaw complete\n");
 }
@@ -1841,9 +1833,10 @@ void page_zero_new_buffers(struct page *page, unsigned from, unsigned to)
 }
 EXPORT_SYMBOL(page_zero_new_buffers);
 
-static int __block_prepare_write(struct inode *inode, struct page *page,
-                unsigned from, unsigned to, get_block_t *get_block)
+int block_prepare_write(struct page *page, unsigned from, unsigned to,
+                get_block_t *get_block)
 {
+        struct inode *inode = page->mapping->host;
         unsigned block_start, block_end;
         sector_t block;
         int err = 0;
@@ -1916,10 +1909,13 @@ static int __block_prepare_write(struct inode *inode, struct page *page,
                 if (!buffer_uptodate(*wait_bh))
                         err = -EIO;
         }
-        if (unlikely(err))
+        if (unlikely(err)) {
                 page_zero_new_buffers(page, from, to);
+                ClearPageUptodate(page);
+        }
         return err;
 }
+EXPORT_SYMBOL(block_prepare_write);
 
 static int __block_commit_write(struct inode *inode, struct page *page,
                 unsigned from, unsigned to)
@@ -1956,62 +1952,40 @@ static int __block_commit_write(struct inode *inode, struct page *page,
         return 0;
 }
 
+int __block_write_begin(struct page *page, loff_t pos, unsigned len,
+                get_block_t *get_block)
+{
+        unsigned start = pos & (PAGE_CACHE_SIZE - 1);
+
+        return block_prepare_write(page, start, start + len, get_block);
+}
+EXPORT_SYMBOL(__block_write_begin);
+
 /*
  * block_write_begin takes care of the basic task of block allocation and
  * bringing partial write blocks uptodate first.
  *
- * If *pagep is not NULL, then block_write_begin uses the locked page
- * at *pagep rather than allocating its own. In this case, the page will
- * not be unlocked or deallocated on failure.
+ * The filesystem needs to handle block truncation upon failure.
  */
-int block_write_begin(struct file *file, struct address_space *mapping,
-                        loff_t pos, unsigned len, unsigned flags,
-                        struct page **pagep, void **fsdata,
-                        get_block_t *get_block)
+int block_write_begin(struct address_space *mapping, loff_t pos, unsigned len,
+                unsigned flags, struct page **pagep, get_block_t *get_block)
 {
-        struct inode *inode = mapping->host;
-        int status = 0;
+        pgoff_t index = pos >> PAGE_CACHE_SHIFT;
         struct page *page;
-        pgoff_t index;
-        unsigned start, end;
-        int ownpage = 0;
+        int status;
 
-        index = pos >> PAGE_CACHE_SHIFT;
-        start = pos & (PAGE_CACHE_SIZE - 1);
-        end = start + len;
-
-        page = *pagep;
-        if (page == NULL) {
-                ownpage = 1;
-                page = grab_cache_page_write_begin(mapping, index, flags);
-                if (!page) {
-                        status = -ENOMEM;
-                        goto out;
-                }
-                *pagep = page;
-        } else
-                BUG_ON(!PageLocked(page));
+        page = grab_cache_page_write_begin(mapping, index, flags);
+        if (!page)
+                return -ENOMEM;
 
-        status = __block_prepare_write(inode, page, start, end, get_block);
+        status = __block_write_begin(page, pos, len, get_block);
         if (unlikely(status)) {
-                ClearPageUptodate(page);
-
-                if (ownpage) {
-                        unlock_page(page);
-                        page_cache_release(page);
-                        *pagep = NULL;
-
-                        /*
-                         * prepare_write() may have instantiated a few blocks
-                         * outside i_size.  Trim these off again. Don't need
-                         * i_size_read because we hold i_mutex.
-                         */
-                        if (pos + len > inode->i_size)
-                                vmtruncate(inode, inode->i_size);
-                }
+                unlock_page(page);
+                page_cache_release(page);
+                page = NULL;
         }
 
-out:
+        *pagep = page;
         return status;
 }
 EXPORT_SYMBOL(block_write_begin);
@@ -2344,7 +2318,7 @@ int cont_write_begin(struct file *file, struct address_space *mapping,
 
         err = cont_expand_zero(file, mapping, pos, bytes);
         if (err)
-                goto out;
+                return err;
 
         zerofrom = *bytes & ~PAGE_CACHE_MASK;
         if (pos+len > *bytes && zerofrom & (blocksize-1)) {
@@ -2352,25 +2326,10 @@ int cont_write_begin(struct file *file, struct address_space *mapping,
                 (*bytes)++;
         }
 
-        *pagep = NULL;
-        err = block_write_begin(file, mapping, pos, len,
-                                flags, pagep, fsdata, get_block);
-out:
-        return err;
+        return block_write_begin(mapping, pos, len, flags, pagep, get_block);
 }
 EXPORT_SYMBOL(cont_write_begin);
 
-int block_prepare_write(struct page *page, unsigned from, unsigned to,
-                        get_block_t *get_block)
-{
-        struct inode *inode = page->mapping->host;
-        int err = __block_prepare_write(inode, page, from, to, get_block);
-        if (err)
-                ClearPageUptodate(page);
-        return err;
-}
-EXPORT_SYMBOL(block_prepare_write);
-
 int block_commit_write(struct page *page, unsigned from, unsigned to)
 {
         struct inode *inode = page->mapping->host;
@@ -2389,7 +2348,7 @@ EXPORT_SYMBOL(block_commit_write);
  *
  * We are not allowed to take the i_mutex here so we have to play games to
  * protect against truncate races as the page could now be beyond EOF.  Because
- * vmtruncate() writes the inode size before removing pages, once we have the
+ * truncate writes the inode size before removing pages, once we have the
  * page lock we can determine safely if the page is beyond EOF. If it is not
  * beyond EOF, then the page is guaranteed safe against truncation until we
  * unlock the page.
@@ -2474,8 +2433,9 @@ static void attach_nobh_buffers(struct page *page, struct buffer_head *head)
 /*
  * On entry, the page is fully not uptodate.
  * On exit the page is fully uptodate in the areas outside (from,to)
+ * The filesystem needs to handle block truncation upon failure.
  */
-int nobh_write_begin(struct file *file, struct address_space *mapping,
+int nobh_write_begin(struct address_space *mapping,
                         loff_t pos, unsigned len, unsigned flags,
                         struct page **pagep, void **fsdata,
                         get_block_t *get_block)
@@ -2508,8 +2468,8 @@ int nobh_write_begin(struct file *file, struct address_space *mapping,
                 unlock_page(page);
                 page_cache_release(page);
                 *pagep = NULL;
-                return block_write_begin(file, mapping, pos, len, flags, pagep,
-                                        fsdata, get_block);
+                return block_write_begin(mapping, pos, len, flags, pagep,
+                                         get_block);
         }
 
         if (PageMappedToDisk(page))
@@ -2613,9 +2573,6 @@ out_release:
         page_cache_release(page);
         *pagep = NULL;
 
-        if (pos + len > inode->i_size)
-                vmtruncate(inode, inode->i_size);
-
         return ret;
 }
 EXPORT_SYMBOL(nobh_write_begin);