diff mbox series

[V2,2/4] ext4: cleanup pagecache before swap i_data

Message ID 20190122065823.67957-3-yangerkun@huawei.com
State Accepted, archived
Headers show
Series fix bugs for ioctl EXT4_IOC_SWAP_BOOT | expand

Commit Message

yangerkun Jan. 22, 2019, 6:58 a.m. UTC 
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 locki 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: yangerkun <yangerkun@huawei.com>
---
 fs/ext4/ioctl.c | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

Comments

Theodore Ts'o Feb. 11, 2019, 5:12 a.m. UTC | #1 
On Tue, Jan 22, 2019 at 02:58:21PM +0800, yangerkun wrote:
> 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 locki 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: yangerkun <yangerkun@huawei.com>

Thanks, applied.

					- Ted
diff mbox series

Patch

diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index 597e8b6..ea05e8d 100644
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -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);