Commit a46c68a3 authored by yangerkun's avatar yangerkun Committed by Theodore Ts'o
Browse files

ext4: cleanup pagecache before swap i_data 



While do swap, we should make sure there has no new dirty page since we
should swap i_data between two inode:
1.We should lock i_mmap_sem with write to avoid new pagecache from mmap
read/write;
2.Change filemap_flush to filemap_write_and_wait and move them to the
space protected by inode lock to avoid new pagecache from buffer read/write.

Signed-off-by: default avataryangerkun <yangerkun@huawei.com>
Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
parent 67a11611

fs/ext4/ioctl.c

+12 −4
Original line number Diff line number Diff line
@@ -121,9 +121,6 @@ static long swap_inode_boot_loader(struct super_block *sb, 
		return PTR_ERR(inode_bl);

	ei_bl = EXT4_I(inode_bl);



	filemap_flush(inode->i_mapping);

	filemap_flush(inode_bl->i_mapping);



	/* Protect orig inodes against a truncate and make sure,

	 * that only 1 swap_inode_boot_loader is running. */

	lock_two_nondirectories(inode, inode_bl);
@@ -141,6 +138,15 @@ static long swap_inode_boot_loader(struct super_block *sb, 
		goto journal_err_out;

	}



	down_write(&EXT4_I(inode)->i_mmap_sem);

	err = filemap_write_and_wait(inode->i_mapping);

	if (err)

		goto err_out;



	err = filemap_write_and_wait(inode_bl->i_mapping);

	if (err)

		goto err_out;



	/* Wait for all existing dio workers */

	inode_dio_wait(inode);

	inode_dio_wait(inode_bl);
@@ -151,7 +157,7 @@ static long swap_inode_boot_loader(struct super_block *sb, 
	handle = ext4_journal_start(inode_bl, EXT4_HT_MOVE_EXTENTS, 2);

	if (IS_ERR(handle)) {

		err = -EINVAL;

		goto journal_err_out;

		goto err_out;

	}



	/* Protect extent tree against block allocations via delalloc */
@@ -208,6 +214,8 @@ static long swap_inode_boot_loader(struct super_block *sb, 
	ext4_journal_stop(handle);

	ext4_double_up_write_data_sem(inode, inode_bl);



err_out:

	up_write(&EXT4_I(inode)->i_mmap_sem);

journal_err_out:

	unlock_two_nondirectories(inode, inode_bl);

	iput(inode_bl);

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