Hi,
On 10/31/2016 06:55 PM, piaojun wrote:
> Hi Eric,
>
> On 2016-10-19 13:19, Eric Ren wrote:
>> The deadlock issue happens when running discontiguous block
>> group testing on multiple nodes. The easier way to reproduce
>> is to do "chmod -R 777 /mnt/ocfs2" things like this on multiple
>> nodes at the same time by pssh.
>>
>> This is indeed another deadlock caused by: commit 743b5f1434f5
>> ("ocfs2: take inode lock in ocfs2_iop_set/get_acl()"). The reason
>> had been explained well by Tariq Saeed in this thread:
>>
>> https://oss.oracle.com/pipermail/ocfs2-devel/2015-September/011085.html
>>
>> For this case, the ocfs2_inode_lock() is misused recursively as below:
>>
>> do_sys_open
>> do_filp_open
>> path_openat
>> may_open
>> inode_permission
>> __inode_permission
>> ocfs2_permission <====== ocfs2_inode_lock()
>> generic_permission
>> get_acl
>> ocfs2_iop_get_acl <====== ocfs2_inode_lock()
>> ocfs2_inode_lock_full_nested <===== deadlock if a remote EX
>> request
> Do you mean another node wants to get ex of the inode? or another process?
Remote EX request means "another node wants to get ex of the inode";-)
Eric
>> comes between two ocfs2_inode_lock()
>>
>> Fix by checking if the cluster lock has been acquired aready in the
>> call-chain
>> path.
>>
>> Fixes: commit 743b5f1434f5 ("ocfs2: take inode lock in
>> ocfs2_iop_set/get_acl()")
>> Signed-off-by: Eric Ren <z...@suse.com>
>> ---
>> fs/ocfs2/acl.c | 39 +++++++++++++++++++++++++++------------
>> 1 file changed, 27 insertions(+), 12 deletions(-)
>>
>> diff --git a/fs/ocfs2/acl.c b/fs/ocfs2/acl.c
>> index bed1fcb..7e3544e 100644
>> --- a/fs/ocfs2/acl.c
>> +++ b/fs/ocfs2/acl.c
>> @@ -283,16 +283,24 @@ int ocfs2_set_acl(handle_t *handle,
>> int ocfs2_iop_set_acl(struct inode *inode, struct posix_acl *acl, int type)
>> {
>> struct buffer_head *bh = NULL;
>> + struct ocfs2_holder *oh;
>> + struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_inode_lockres;
>> int status = 0;
>>
>> - status = ocfs2_inode_lock(inode, &bh, 1);
>> - if (status < 0) {
>> - if (status != -ENOENT)
>> - mlog_errno(status);
>> - return status;
>> + oh = ocfs2_is_locked_by_me(lockres);
>> + if (!oh) {
>> + status = ocfs2_inode_lock(inode, &bh, 1);
>> + if (status < 0) {
>> + if (status != -ENOENT)
>> + mlog_errno(status);
>> + return status;
>> + }
>> }
>> +
>> status = ocfs2_set_acl(NULL, inode, bh, type, acl, NULL, NULL);
>> - ocfs2_inode_unlock(inode, 1);
>> +
>> + if (!oh)
>> + ocfs2_inode_unlock(inode, 1);
>> brelse(bh);
>> return status;
>> }
>> @@ -302,21 +310,28 @@ struct posix_acl *ocfs2_iop_get_acl(struct inode
>> *inode, int type)
>> struct ocfs2_super *osb;
>> struct buffer_head *di_bh = NULL;
>> struct posix_acl *acl;
>> + struct ocfs2_holder *oh;
>> + struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_inode_lockres;
>> int ret;
>>
>> osb = OCFS2_SB(inode->i_sb);
>> if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
>> return NULL;
>> - ret = ocfs2_inode_lock(inode, &di_bh, 0);
>> - if (ret < 0) {
>> - if (ret != -ENOENT)
>> - mlog_errno(ret);
>> - return ERR_PTR(ret);
>> +
>> + oh = ocfs2_is_locked_by_me(lockres);
>> + if (!oh) {
>> + ret = ocfs2_inode_lock(inode, &di_bh, 0);
>> + if (ret < 0) {
>> + if (ret != -ENOENT)
>> + mlog_errno(ret);
>> + return ERR_PTR(ret);
>> + }
>> }
>>
>> acl = ocfs2_get_acl_nolock(inode, type, di_bh);
>>
>> - ocfs2_inode_unlock(inode, 0);
>> + if (!oh)
>> + ocfs2_inode_unlock(inode, 0);
>> brelse(di_bh);
>> return acl;
>> }
>>
>
_______________________________________________
Ocfs2-devel mailing list
Ocfs2-devel@oss.oracle.com
https://oss.oracle.com/mailman/listinfo/ocfs2-devel
