Commit cb22c668 authored by Jan Kara's avatar Jan Kara Committed by Greg Kroah-Hartman

udf: Fix deadlock between writeback and udf_setsize()

commit f2e95355 upstream.

udf_setsize() called truncate_setsize() with i_data_sem held. Thus
truncate_pagecache() called from truncate_setsize() could lock a page
under i_data_sem which can deadlock as page lock ranks below
i_data_sem - e. g. writeback can hold page lock and try to acquire
i_data_sem to map a block.

Fix the problem by moving truncate_setsize() calls from under
i_data_sem. It is safe for us to change i_size without holding
i_data_sem as all the places that depend on i_size being stable already
hold inode_lock.

Fixes: 7e49b6f2Signed-off-by: default avatarJan Kara <jack@suse.cz>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 47a49322
......@@ -1222,8 +1222,8 @@ int udf_setsize(struct inode *inode, loff_t newsize)
return err;
}
set_size:
truncate_setsize(inode, newsize);
up_write(&iinfo->i_data_sem);
truncate_setsize(inode, newsize);
} else {
if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
down_write(&iinfo->i_data_sem);
......@@ -1240,9 +1240,9 @@ int udf_setsize(struct inode *inode, loff_t newsize)
udf_get_block);
if (err)
return err;
truncate_setsize(inode, newsize);
down_write(&iinfo->i_data_sem);
udf_clear_extent_cache(inode);
truncate_setsize(inode, newsize);
udf_truncate_extents(inode);
up_write(&iinfo->i_data_sem);
}
......
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