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Commit 678aaf48 authored by Jan Kara's avatar Jan Kara Committed by Theodore Ts'o
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ext4: Use new framework for data=ordered mode in JBD2 



This patch makes ext4 use inode-based implementation of data=ordered mode
in JBD2. It allows us to unify some data=ordered and data=writeback paths
(especially writepage since we don't have to start a transaction anymore)
and remove some buffer walking.

Updated fix from Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
to fix file system hang due to corrupt jinode values.

Signed-off-by: default avatarJan Kara <jack@suse.cz>
Signed-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: default avatarMingming Cao <cmm@us.ibm.com>
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
parent c851ed54

fs/ext4/ext4_i.h

+1 −0
Original line number Diff line number Diff line
@@ -150,6 +150,7 @@ struct ext4_inode_info { 
	 */

	struct rw_semaphore i_data_sem;

	struct inode vfs_inode;

	struct jbd2_inode jinode;



	unsigned long i_ext_generation;

	struct ext4_ext_cache i_cached_extent;

fs/ext4/ext4_jbd2.h

+5 −2
Original line number Diff line number Diff line
@@ -154,8 +154,6 @@ int __ext4_journal_dirty_metadata(const char *where, 
#define ext4_journal_forget(handle, bh) \

	__ext4_journal_forget(__func__, (handle), (bh))



int ext4_journal_dirty_data(handle_t *handle, struct buffer_head *bh);



handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks);

int __ext4_journal_stop(const char *where, handle_t *handle);
@@ -192,6 +190,11 @@ static inline int ext4_journal_force_commit(journal_t *journal) 
	return jbd2_journal_force_commit(journal);

}



static inline int ext4_jbd2_file_inode(handle_t *handle, struct inode *inode)

{

	return jbd2_journal_file_inode(handle, &EXT4_I(inode)->jinode);

}



/* super.c */

int ext4_force_commit(struct super_block *sb);

fs/ext4/inode.c

+49 −109
Original line number Diff line number Diff line
@@ -39,6 +39,13 @@ 
#include "xattr.h"

#include "acl.h"



static inline int ext4_begin_ordered_truncate(struct inode *inode,

					      loff_t new_size)

{

	return jbd2_journal_begin_ordered_truncate(&EXT4_I(inode)->jinode,

						   new_size);

}



/*

 * Test whether an inode is a fast symlink.

 */
@@ -181,6 +188,8 @@ void ext4_delete_inode (struct inode * inode) 
{

	handle_t *handle;



	if (ext4_should_order_data(inode))

		ext4_begin_ordered_truncate(inode, 0);

	truncate_inode_pages(&inode->i_data, 0);



	if (is_bad_inode(inode))
@@ -1273,15 +1282,6 @@ out: 
	return ret;

}



int ext4_journal_dirty_data(handle_t *handle, struct buffer_head *bh)

{

	int err = jbd2_journal_dirty_data(handle, bh);

	if (err)

		ext4_journal_abort_handle(__func__, __func__,

						bh, handle, err);

	return err;

}



/* For write_end() in data=journal mode */

static int write_end_fn(handle_t *handle, struct buffer_head *bh)

{
@@ -1311,8 +1311,7 @@ static int ext4_ordered_write_end(struct file *file, 
	from = pos & (PAGE_CACHE_SIZE - 1);

	to = from + len;



	ret = walk_page_buffers(handle, page_buffers(page),

		from, to, NULL, ext4_journal_dirty_data);

	ret = ext4_jbd2_file_inode(handle, inode);



	if (ret == 0) {

		/*
@@ -1472,25 +1471,22 @@ static int bput_one(handle_t *handle, struct buffer_head *bh) 
	return 0;

}



static int jbd2_journal_dirty_data_fn(handle_t *handle, struct buffer_head *bh)

{

	if (buffer_mapped(bh))

		return ext4_journal_dirty_data(handle, bh);

	return 0;

}



static int ext4_bh_unmapped_or_delay(handle_t *handle, struct buffer_head *bh)

{

	return !buffer_mapped(bh) || buffer_delay(bh);

}



/*

 * Note that we don't need to start a transaction unless we're journaling

 * data because we should have holes filled from ext4_page_mkwrite(). If

 * we are journaling data, we cannot start transaction directly because

 * transaction start ranks above page lock so we have to do some magic...

 * Note that we don't need to start a transaction unless we're journaling data

 * because we should have holes filled from ext4_page_mkwrite(). We even don't

 * need to file the inode to the transaction's list in ordered mode because if

 * we are writing back data added by write(), the inode is already there and if

 * we are writing back data modified via mmap(), noone guarantees in which

 * transaction the data will hit the disk. In case we are journaling data, we

 * cannot start transaction directly because transaction start ranks above page

 * lock so we have to do some magic.

 *

 * In all journalling modes block_write_full_page() will start the I/O.

 * In all journaling modes block_write_full_page() will start the I/O.

 *

 * Problem:

 *
@@ -1533,86 +1529,7 @@ static int ext4_bh_unmapped_or_delay(handle_t *handle, struct buffer_head *bh) 
 * us.

 *

 */

static int __ext4_ordered_writepage(struct page *page,

				struct writeback_control *wbc)

{

	struct inode *inode = page->mapping->host;

	struct buffer_head *page_bufs;

	handle_t *handle = NULL;

	int ret = 0;

	int err;



	if (!page_has_buffers(page)) {

		create_empty_buffers(page, inode->i_sb->s_blocksize,

				(1 << BH_Dirty)|(1 << BH_Uptodate));

	}

	page_bufs = page_buffers(page);

	walk_page_buffers(handle, page_bufs, 0,

			PAGE_CACHE_SIZE, NULL, bget_one);



	ret = block_write_full_page(page, ext4_get_block, wbc);



	/*

	 * The page can become unlocked at any point now, and

	 * truncate can then come in and change things.  So we

	 * can't touch *page from now on.  But *page_bufs is

	 * safe due to elevated refcount.

	 */



	/*

	 * And attach them to the current transaction.  But only if

	 * block_write_full_page() succeeded.  Otherwise they are unmapped,

	 * and generally junk.

	 */

	if (ret == 0) {

		handle = ext4_journal_start(inode,

					ext4_writepage_trans_blocks(inode));

		if (IS_ERR(handle)) {

			ret = PTR_ERR(handle);

			goto out_put;

		}



		ret = walk_page_buffers(handle, page_bufs, 0, PAGE_CACHE_SIZE,

					NULL, jbd2_journal_dirty_data_fn);

		err = ext4_journal_stop(handle);

		if (!ret)

			ret = err;

	}

out_put:

	walk_page_buffers(handle, page_bufs, 0, PAGE_CACHE_SIZE, NULL,

			  bput_one);

	return ret;

}



static int ext4_ordered_writepage(struct page *page,

				struct writeback_control *wbc)

{

	struct inode *inode = page->mapping->host;

	loff_t size = i_size_read(inode);

	loff_t len;



	J_ASSERT(PageLocked(page));

	J_ASSERT(page_has_buffers(page));

	if (page->index == size >> PAGE_CACHE_SHIFT)

		len = size & ~PAGE_CACHE_MASK;

	else

		len = PAGE_CACHE_SIZE;

	BUG_ON(walk_page_buffers(NULL, page_buffers(page), 0, len, NULL,

				 ext4_bh_unmapped_or_delay));



	/*

	 * We give up here if we're reentered, because it might be for a

	 * different filesystem.

	 */

	if (!ext4_journal_current_handle())

		return __ext4_ordered_writepage(page, wbc);



	redirty_page_for_writepage(wbc, page);

	unlock_page(page);

	return 0;

}



static int __ext4_writeback_writepage(struct page *page,

static int __ext4_normal_writepage(struct page *page,

				struct writeback_control *wbc)

{

	struct inode *inode = page->mapping->host;
@@ -1624,7 +1541,7 @@ static int __ext4_writeback_writepage(struct page *page, 
}





static int ext4_writeback_writepage(struct page *page,

static int ext4_normal_writepage(struct page *page,

				struct writeback_control *wbc)

{

	struct inode *inode = page->mapping->host;
@@ -1641,7 +1558,7 @@ static int ext4_writeback_writepage(struct page *page, 
				 ext4_bh_unmapped_or_delay));



	if (!ext4_journal_current_handle())

		return __ext4_writeback_writepage(page, wbc);

		return __ext4_normal_writepage(page, wbc);



	redirty_page_for_writepage(wbc, page);

	unlock_page(page);
@@ -1877,7 +1794,7 @@ static int ext4_journalled_set_page_dirty(struct page *page) 
static const struct address_space_operations ext4_ordered_aops = {

	.readpage	= ext4_readpage,

	.readpages	= ext4_readpages,

	.writepage	= ext4_ordered_writepage,

	.writepage	= ext4_normal_writepage,

	.sync_page	= block_sync_page,

	.write_begin	= ext4_write_begin,

	.write_end	= ext4_ordered_write_end,
@@ -1891,7 +1808,7 @@ static const struct address_space_operations ext4_ordered_aops = { 
static const struct address_space_operations ext4_writeback_aops = {

	.readpage	= ext4_readpage,

	.readpages	= ext4_readpages,

	.writepage	= ext4_writeback_writepage,

	.writepage	= ext4_normal_writepage,

	.sync_page	= block_sync_page,

	.write_begin	= ext4_write_begin,

	.write_end	= ext4_writeback_write_end,
@@ -2019,7 +1936,7 @@ int ext4_block_truncate_page(handle_t *handle, 
		err = ext4_journal_dirty_metadata(handle, bh);

	} else {

		if (ext4_should_order_data(inode))

			err = ext4_journal_dirty_data(handle, bh);

			err = ext4_jbd2_file_inode(handle, inode);

		mark_buffer_dirty(bh);

	}
@@ -3171,7 +3088,14 @@ int ext4_write_inode(struct inode *inode, int wait) 
 * be freed, so we have a strong guarantee that no future commit will

 * leave these blocks visible to the user.)

 *

 * Called with inode->sem down.

 * Another thing we have to assure is that if we are in ordered mode

 * and inode is still attached to the committing transaction, we must

 * we start writeout of all the dirty pages which are being truncated.

 * This way we are sure that all the data written in the previous

 * transaction are already on disk (truncate waits for pages under

 * writeback).

 *

 * Called with inode->i_mutex down.

 */

int ext4_setattr(struct dentry *dentry, struct iattr *attr)

{
@@ -3237,6 +3161,22 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr) 
		if (!error)

			error = rc;

		ext4_journal_stop(handle);



		if (ext4_should_order_data(inode)) {

			error = ext4_begin_ordered_truncate(inode,

							    attr->ia_size);

			if (error) {

				/* Do as much error cleanup as possible */

				handle = ext4_journal_start(inode, 3);

				if (IS_ERR(handle)) {

					ext4_orphan_del(NULL, inode);

					goto err_out;

				}

				ext4_orphan_del(handle, inode);

				ext4_journal_stop(handle);

				goto err_out;

			}

		}

	}



	rc = inode_setattr(inode, attr);

fs/ext4/super.c

+4 −1
Original line number Diff line number Diff line
@@ -573,6 +573,7 @@ static struct inode *ext4_alloc_inode(struct super_block *sb) 
	memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));

	INIT_LIST_HEAD(&ei->i_prealloc_list);

	spin_lock_init(&ei->i_prealloc_lock);

	jbd2_journal_init_jbd_inode(&ei->jinode, &ei->vfs_inode);

	return &ei->vfs_inode;

}
@@ -637,6 +638,8 @@ static void ext4_clear_inode(struct inode *inode) 
	EXT4_I(inode)->i_block_alloc_info = NULL;

	if (unlikely(rsv))

		kfree(rsv);

	jbd2_journal_release_jbd_inode(EXT4_SB(inode->i_sb)->s_journal,

				       &EXT4_I(inode)->jinode);

}



static inline void ext4_show_quota_options(struct seq_file *seq, struct super_block *sb)
@@ -3378,7 +3381,7 @@ static ssize_t ext4_quota_write(struct super_block *sb, int type, 
			err = ext4_journal_dirty_metadata(handle, bh);

		else {

			/* Always do at least ordered writes for quotas */

			err = ext4_journal_dirty_data(handle, bh);

			err = ext4_jbd2_file_inode(handle, inode);

			mark_buffer_dirty(bh);

		}

		brelse(bh);