ext4: Fix lock inversion in ext4_ext_truncate()
We cannot call ext4_orphan_add() from under i_data_sem because that
causes a lock ordering violation between i_data_sem and and the
superblock lock.
Updated with Aneesh's locking order fix
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index b722bce..7844bbb 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -2768,6 +2768,9 @@
if (inode->i_size & (sb->s_blocksize - 1))
ext4_block_truncate_page(handle, mapping, inode->i_size);
+ if (ext4_orphan_add(handle, inode))
+ goto out_stop;
+
down_write(&EXT4_I(inode)->i_data_sem);
ext4_ext_invalidate_cache(inode);
@@ -2778,8 +2781,6 @@
* Probably we need not scan at all,
* because page truncation is enough.
*/
- if (ext4_orphan_add(handle, inode))
- goto out_stop;
/* we have to know where to truncate from in crash case */
EXT4_I(inode)->i_disksize = inode->i_size;
@@ -2796,6 +2797,7 @@
handle->h_sync = 1;
out_stop:
+ up_write(&EXT4_I(inode)->i_data_sem);
/*
* If this was a simple ftruncate() and the file will remain alive,
* then we need to clear up the orphan record which we created above.
@@ -2806,7 +2808,6 @@
if (inode->i_nlink)
ext4_orphan_del(handle, inode);
- up_write(&EXT4_I(inode)->i_data_sem);
inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
ext4_mark_inode_dirty(handle, inode);
ext4_journal_stop(handle);