[PATCH] revert ext3-writepages-support-for-writeback-mode

This had a fatal lock ranking bug: we do journal_start outside
mpage_writepages()'s lock_page().

Revert the whole thing, think again.

Credit-to: Jan Kara <jack@suse.cz>

For identifying the bug.

Cc: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c
index ea58886..0d5fa73 100644 (file)
--- a/fs/ext3/inode.c
+++ b/fs/ext3/inode.c
@@ -844,12 +844,6 @@ get_block:
        return ret;
 }
 
-static int ext3_writepages_get_block(struct inode *inode, sector_t iblock,
-                       struct buffer_head *bh, int create)
-{
-       return ext3_direct_io_get_blocks(inode, iblock, 1, bh, create);
-}
-
 /*
  * `handle' can be NULL if create is zero
  */
@@ -1323,45 +1317,6 @@ out_fail:
        return ret;
 }
 
-static int
-ext3_writeback_writepage_helper(struct page *page,
-                               struct writeback_control *wbc)
-{
-       return block_write_full_page(page, ext3_get_block, wbc);
-}
-
-static int
-ext3_writeback_writepages(struct address_space *mapping,
-                               struct writeback_control *wbc)
-{
-       struct inode *inode = mapping->host;
-       handle_t *handle = NULL;
-       int err, ret = 0;
-
-       if (!mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
-               return ret;
-
-       handle = ext3_journal_start(inode, ext3_writepage_trans_blocks(inode));
-       if (IS_ERR(handle)) {
-               ret = PTR_ERR(handle);
-               return ret;
-       }
-
-        ret = __mpage_writepages(mapping, wbc, ext3_writepages_get_block,
-                                       ext3_writeback_writepage_helper);
-
-       /*
-        * Need to reaquire the handle since ext3_writepages_get_block()
-        * can restart the handle
-        */
-       handle = journal_current_handle();
-
-       err = ext3_journal_stop(handle);
-       if (!ret)
-               ret = err;
-       return ret;
-}
-
 static int ext3_writeback_writepage(struct page *page,
                                struct writeback_control *wbc)
 {
@@ -1599,7 +1554,6 @@ static struct address_space_operations ext3_writeback_aops = {
        .readpage       = ext3_readpage,
        .readpages      = ext3_readpages,
        .writepage      = ext3_writeback_writepage,
-       .writepages     = ext3_writeback_writepages,
        .sync_page      = block_sync_page,
        .prepare_write  = ext3_prepare_write,
        .commit_write   = ext3_writeback_commit_write,

diff --git a/fs/mpage.c b/fs/mpage.c
index 32c7c8f..68db525 100644 (file)
--- a/fs/mpage.c
+++ b/fs/mpage.c
@@ -627,15 +627,6 @@ int
 mpage_writepages(struct address_space *mapping,
                struct writeback_control *wbc, get_block_t get_block)
 {
-       return __mpage_writepages(mapping, wbc, get_block,
-               mapping->a_ops->writepage);
-}
-
-int
-__mpage_writepages(struct address_space *mapping,
-               struct writeback_control *wbc, get_block_t get_block,
-               writepage_t writepage_fn)
-{
        struct backing_dev_info *bdi = mapping->backing_dev_info;
        struct bio *bio = NULL;
        sector_t last_block_in_bio = 0;
@@ -725,7 +716,7 @@ retry:
                        } else {
                                bio = __mpage_writepage(bio, page, get_block,
                                                &last_block_in_bio, &ret, wbc,
-                                               writepage_fn);
+                                               page->mapping->a_ops->writepage);
                        }
                        if (unlikely(ret == WRITEPAGE_ACTIVATE))
                                unlock_page(page);
@@ -755,7 +746,6 @@ retry:
        return ret;
 }
 EXPORT_SYMBOL(mpage_writepages);
-EXPORT_SYMBOL(__mpage_writepages);
 
 int mpage_writepage(struct page *page, get_block_t get_block,
        struct writeback_control *wbc)

diff --git a/include/linux/mpage.h b/include/linux/mpage.h
index dea1b00..3ca8804 100644 (file)
--- a/include/linux/mpage.h
+++ b/include/linux/mpage.h
@@ -20,9 +20,6 @@ int mpage_writepages(struct address_space *mapping,
                struct writeback_control *wbc, get_block_t get_block);
 int mpage_writepage(struct page *page, get_block_t *get_block,
                struct writeback_control *wbc);
-int __mpage_writepages(struct address_space *mapping,
-               struct writeback_control *wbc, get_block_t get_block,
-               writepage_t writepage);
 
 static inline int
 generic_writepages(struct address_space *mapping, struct writeback_control *wbc)