ext4: add lockdep annotations for i_data_sem
With the internal Quota feature, mke2fs creates empty quota inodes and
quota usage tracking is enabled as soon as the file system is mounted.
Since quotacheck is no longer preallocating all of the blocks in the
quota inode that are likely needed to be written to, we are now seeing
a lockdep false positive caused by needing to allocate a quota block
from inside ext4_map_blocks(), while holding i_data_sem for a data
inode. This results in this complaint:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&ei->i_data_sem);
lock(&s->s_dquot.dqio_mutex);
lock(&ei->i_data_sem);
lock(&s->s_dquot.dqio_mutex);
Google-Bug-Id: 27907753
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c
index 4098acc..796ff0e 100644
--- a/fs/ext4/move_extent.c
+++ b/fs/ext4/move_extent.c
@@ -60,10 +60,10 @@
{
if (first < second) {
down_write(&EXT4_I(first)->i_data_sem);
- down_write_nested(&EXT4_I(second)->i_data_sem, SINGLE_DEPTH_NESTING);
+ down_write_nested(&EXT4_I(second)->i_data_sem, I_DATA_SEM_OTHER);
} else {
down_write(&EXT4_I(second)->i_data_sem);
- down_write_nested(&EXT4_I(first)->i_data_sem, SINGLE_DEPTH_NESTING);
+ down_write_nested(&EXT4_I(first)->i_data_sem, I_DATA_SEM_OTHER);
}
}
@@ -484,6 +484,13 @@
return -EBUSY;
}
+ if (IS_NOQUOTA(orig_inode) || IS_NOQUOTA(donor_inode)) {
+ ext4_debug("ext4 move extent: The argument files should "
+ "not be quota files [ino:orig %lu, donor %lu]\n",
+ orig_inode->i_ino, donor_inode->i_ino);
+ return -EBUSY;
+ }
+
/* Ext4 move extent supports only extent based file */
if (!(ext4_test_inode_flag(orig_inode, EXT4_INODE_EXTENTS))) {
ext4_debug("ext4 move extent: orig file is not extents "