redonkable/alistair23-linux
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ext4: fix incorrect lock ordering for ext4_ind_migrate

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existing locking ordering: journal-> i_data_sem, but
ext4_ind_migrate() grab locks in opposite order which may result in
deadlock.

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This commit is contained in:
Dmitry Monakhov 2013-04-08 13:02:25 -04:00 committed by Theodore Ts'o
parent 393d1d1d76
commit e8238f9a83
1 changed files with 5 additions and 7 deletions
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12
fs/ext4/extents.c
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@ -4735,6 +4735,10 @@ int ext4_ind_migrate(struct inode *inode)
(!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
return -EINVAL;
handle = ext4_journal_start(inode, EXT4_HT_MIGRATE, 1);
if (IS_ERR(handle))
return PTR_ERR(handle);
down_write(&EXT4_I(inode)->i_data_sem);
ret = ext4_ext_check_inode(inode);
if (ret)
@ -4758,19 +4762,13 @@ int ext4_ind_migrate(struct inode *inode)
}
}
handle = ext4_journal_start(inode, EXT4_HT_MIGRATE, 1);
if (IS_ERR(handle)) {
ret = PTR_ERR(handle);
goto errout;
}
ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
memset(ei->i_data, 0, sizeof(ei->i_data));
for (i=0; i < len; i++)
ei->i_data[i] = cpu_to_le32(blk++);
ext4_mark_inode_dirty(handle, inode);
ext4_journal_stop(handle);
errout:
ext4_journal_stop(handle);
up_write(&EXT4_I(inode)->i_data_sem);
return ret;
}