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
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;
}
--
2.6.6
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