From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Simmons Date: Wed, 15 Jul 2020 16:45:11 -0400 Subject: [lustre-devel] [PATCH 30/37] lustre: llite: annotate non-owner locking In-Reply-To: <1594845918-29027-1-git-send-email-jsimmons@infradead.org> References: <1594845918-29027-1-git-send-email-jsimmons@infradead.org> Message-ID: <1594845918-29027-31-git-send-email-jsimmons@infradead.org> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: lustre-devel@lists.lustre.org From: Mr NeilBrown The lli_lsm_sem locks taken by ll_prep_md_op_data() are sometimes released by a different thread. This confuses lockdep unless we explain the situation. So use down_read_non_owner() and up_read_non_owner(). WC-bug-id: https://jira.whamcloud.com/browse/LU-9679 Lustre-commit: f34392412fe22 ("LU-9679 llite: annotate non-owner locking") Signed-off-by: Mr NeilBrown Reviewed-on: https://review.whamcloud.com/39234 Reviewed-by: Andreas Dilger Reviewed-by: James Simmons Reviewed-by: Shaun Tancheff Reviewed-by: Oleg Drokin Signed-off-by: James Simmons --- fs/lustre/llite/llite_lib.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/fs/lustre/llite/llite_lib.c b/fs/lustre/llite/llite_lib.c index c62e182..f52d2b5 100644 --- a/fs/lustre/llite/llite_lib.c +++ b/fs/lustre/llite/llite_lib.c @@ -2783,12 +2783,12 @@ int ll_obd_statfs(struct inode *inode, void __user *arg) void ll_unlock_md_op_lsm(struct md_op_data *op_data) { if (op_data->op_mea2_sem) { - up_read(op_data->op_mea2_sem); + up_read_non_owner(op_data->op_mea2_sem); op_data->op_mea2_sem = NULL; } if (op_data->op_mea1_sem) { - up_read(op_data->op_mea1_sem); + up_read_non_owner(op_data->op_mea1_sem); op_data->op_mea1_sem = NULL; } } @@ -2823,7 +2823,7 @@ struct md_op_data *ll_prep_md_op_data(struct md_op_data *op_data, op_data->op_code = opc; if (S_ISDIR(i1->i_mode)) { - down_read(&ll_i2info(i1)->lli_lsm_sem); + down_read_non_owner(&ll_i2info(i1)->lli_lsm_sem); op_data->op_mea1_sem = &ll_i2info(i1)->lli_lsm_sem; op_data->op_mea1 = ll_i2info(i1)->lli_lsm_md; op_data->op_default_mea1 = ll_i2info(i1)->lli_default_lsm_md; @@ -2833,7 +2833,10 @@ struct md_op_data *ll_prep_md_op_data(struct md_op_data *op_data, op_data->op_fid2 = *ll_inode2fid(i2); if (S_ISDIR(i2->i_mode)) { if (i2 != i1) { - down_read(&ll_i2info(i2)->lli_lsm_sem); + /* i2 is typically a child of i1, and MUST be + * further from the root to avoid deadlocks. + */ + down_read_non_owner(&ll_i2info(i2)->lli_lsm_sem); op_data->op_mea2_sem = &ll_i2info(i2)->lli_lsm_sem; } -- 1.8.3.1