Messages in this thread Patch in this message | | | Date | Fri, 13 Mar 2009 18:11:10 -0700 | From | Greg KH <> | Subject | [patch 093/114] ext4: Fix lockdep warning |
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2.6.28-stable review patch. If anyone has any objections, please let us know.
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From: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
(cherry picked from commit ba4439165f0f0d25b2fe065cf0c1ff8130b802eb)
We should not call ext4_mb_add_n_trim while holding alloc_semp.
============================================= [ INFO: possible recursive locking detected ] 2.6.29-rc4-git1-dirty #124 --------------------------------------------- ffsb/3116 is trying to acquire lock: (&meta_group_info[i]->alloc_sem){----}, at: [<ffffffff8035a6e8>] ext4_mb_load_buddy+0xd2/0x343
but task is already holding lock: (&meta_group_info[i]->alloc_sem){----}, at: [<ffffffff8035a6e8>] ext4_mb_load_buddy+0xd2/0x343
http://bugzilla.kernel.org/show_bug.cgi?id=12672
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- fs/ext4/mballoc.c | 29 ++++++++++++++++------------- 1 file changed, 16 insertions(+), 13 deletions(-)
--- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -4456,23 +4456,26 @@ static int ext4_mb_release_context(struc pa->pa_free -= ac->ac_b_ex.fe_len; pa->pa_len -= ac->ac_b_ex.fe_len; spin_unlock(&pa->pa_lock); - /* - * We want to add the pa to the right bucket. - * Remove it from the list and while adding - * make sure the list to which we are adding - * doesn't grow big. - */ - if (likely(pa->pa_free)) { - spin_lock(pa->pa_obj_lock); - list_del_rcu(&pa->pa_inode_list); - spin_unlock(pa->pa_obj_lock); - ext4_mb_add_n_trim(ac); - } } - ext4_mb_put_pa(ac, ac->ac_sb, pa); } if (ac->alloc_semp) up_read(ac->alloc_semp); + if (pa) { + /* + * We want to add the pa to the right bucket. + * Remove it from the list and while adding + * make sure the list to which we are adding + * doesn't grow big. We need to release + * alloc_semp before calling ext4_mb_add_n_trim() + */ + if (pa->pa_linear && likely(pa->pa_free)) { + spin_lock(pa->pa_obj_lock); + list_del_rcu(&pa->pa_inode_list); + spin_unlock(pa->pa_obj_lock); + ext4_mb_add_n_trim(ac); + } + ext4_mb_put_pa(ac, ac->ac_sb, pa); + } if (ac->ac_bitmap_page) page_cache_release(ac->ac_bitmap_page); if (ac->ac_buddy_page)
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