Commit f8514083 authored by Aneesh Kumar K.V's avatar Aneesh Kumar K.V Committed by Theodore Ts'o
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ext4: truncate the file properly if we fail to copy data from userspace 



In generic_perform_write if we fail to copy the user data we don't
update the inode->i_size.  We should truncate the file in the above
case so that we don't have blocks allocated outside inode->i_size.  Add
the inode to orphan list in the same transaction as block allocation
This ensures that if we crash in between the recovery would do the
truncate.

Signed-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
CC:  Jan Kara <jack@suse.cz>
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
parent 1938a150

fs/ext4/inode.c

+102 −26
Original line number Diff line number Diff line
@@ -1549,6 +1549,52 @@ static int write_end_fn(handle_t *handle, struct buffer_head *bh) 
	return ext4_handle_dirty_metadata(handle, NULL, bh);

}



static int ext4_generic_write_end(struct file *file,

				struct address_space *mapping,

				loff_t pos, unsigned len, unsigned copied,

				struct page *page, void *fsdata)

{

	int i_size_changed = 0;

	struct inode *inode = mapping->host;

	handle_t *handle = ext4_journal_current_handle();



	copied = block_write_end(file, mapping, pos, len, copied, page, fsdata);



	/*

	 * No need to use i_size_read() here, the i_size

	 * cannot change under us because we hold i_mutex.

	 *

	 * But it's important to update i_size while still holding page lock:

	 * page writeout could otherwise come in and zero beyond i_size.

	 */

	if (pos + copied > inode->i_size) {

		i_size_write(inode, pos + copied);

		i_size_changed = 1;

	}



	if (pos + copied >  EXT4_I(inode)->i_disksize) {

		/* We need to mark inode dirty even if

		 * new_i_size is less that inode->i_size

		 * bu greater than i_disksize.(hint delalloc)

		 */

		ext4_update_i_disksize(inode, (pos + copied));

		i_size_changed = 1;

	}

	unlock_page(page);

	page_cache_release(page);



	/*

	 * Don't mark the inode dirty under page lock. First, it unnecessarily

	 * makes the holding time of page lock longer. Second, it forces lock

	 * ordering of page lock and transaction start for journaling

	 * filesystems.

	 */

	if (i_size_changed)

		ext4_mark_inode_dirty(handle, inode);



	return copied;

}



/*

 * We need to pick up the new inode size which generic_commit_write gave us

 * `file' can be NULL - eg, when called from page_symlink().
@@ -1572,21 +1618,15 @@ static int ext4_ordered_write_end(struct file *file, 
	ret = ext4_jbd2_file_inode(handle, inode);



	if (ret == 0) {

		loff_t new_i_size;



		new_i_size = pos + copied;

		if (new_i_size > EXT4_I(inode)->i_disksize) {

			ext4_update_i_disksize(inode, new_i_size);

			/* We need to mark inode dirty even if

			 * new_i_size is less that inode->i_size

			 * bu greater than i_disksize.(hint delalloc)

			 */

			ext4_mark_inode_dirty(handle, inode);

		}



		ret2 = generic_write_end(file, mapping, pos, len, copied,

		ret2 = ext4_generic_write_end(file, mapping, pos, len, copied,

							page, fsdata);

		copied = ret2;

		if (pos + len > inode->i_size)

			/* if we have allocated more blocks and copied

			 * less. We will have blocks allocated outside

			 * inode->i_size. So truncate them

			 */

			ext4_orphan_add(handle, inode);

		if (ret2 < 0)

			ret = ret2;

	}
@@ -1594,6 +1634,18 @@ static int ext4_ordered_write_end(struct file *file, 
	if (!ret)

		ret = ret2;



	if (pos + len > inode->i_size) {

		vmtruncate(inode, inode->i_size);

		/* 

		 * If vmtruncate failed early the inode might still be

		 * on the orphan list; we need to make sure the inode

		 * is removed from the orphan list in that case.

		 */

		if (inode->i_nlink)

			ext4_orphan_del(NULL, inode);

	}





	return ret ? ret : copied;

}
@@ -1605,25 +1657,21 @@ static int ext4_writeback_write_end(struct file *file, 
	handle_t *handle = ext4_journal_current_handle();

	struct inode *inode = mapping->host;

	int ret = 0, ret2;

	loff_t new_i_size;



	trace_mark(ext4_writeback_write_end,

		   "dev %s ino %lu pos %llu len %u copied %u",

		   inode->i_sb->s_id, inode->i_ino,

		   (unsigned long long) pos, len, copied);

	new_i_size = pos + copied;

	if (new_i_size > EXT4_I(inode)->i_disksize) {

		ext4_update_i_disksize(inode, new_i_size);

		/* We need to mark inode dirty even if

		 * new_i_size is less that inode->i_size

		 * bu greater than i_disksize.(hint delalloc)

		 */

		ext4_mark_inode_dirty(handle, inode);

	}



	ret2 = generic_write_end(file, mapping, pos, len, copied,

	ret2 = ext4_generic_write_end(file, mapping, pos, len, copied,

							page, fsdata);

	copied = ret2;

	if (pos + len > inode->i_size)

		/* if we have allocated more blocks and copied

		 * less. We will have blocks allocated outside

		 * inode->i_size. So truncate them

		 */

		ext4_orphan_add(handle, inode);



	if (ret2 < 0)

		ret = ret2;
@@ -1631,6 +1679,17 @@ static int ext4_writeback_write_end(struct file *file, 
	if (!ret)

		ret = ret2;



	if (pos + len > inode->i_size) {

		vmtruncate(inode, inode->i_size);

		/* 

		 * If vmtruncate failed early the inode might still be

		 * on the orphan list; we need to make sure the inode

		 * is removed from the orphan list in that case.

		 */

		if (inode->i_nlink)

			ext4_orphan_del(NULL, inode);

	}



	return ret ? ret : copied;

}
@@ -1675,10 +1734,27 @@ static int ext4_journalled_write_end(struct file *file, 
	}



	unlock_page(page);

	page_cache_release(page);

	if (pos + len > inode->i_size)

		/* if we have allocated more blocks and copied

		 * less. We will have blocks allocated outside

		 * inode->i_size. So truncate them

		 */

		ext4_orphan_add(handle, inode);



	ret2 = ext4_journal_stop(handle);

	if (!ret)

		ret = ret2;

	page_cache_release(page);

	if (pos + len > inode->i_size) {

		vmtruncate(inode, inode->i_size);

		/* 

		 * If vmtruncate failed early the inode might still be

		 * on the orphan list; we need to make sure the inode

		 * is removed from the orphan list in that case.

		 */

		if (inode->i_nlink)

			ext4_orphan_del(NULL, inode);

	}



	return ret ? ret : copied;

}

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