On 5/17/22 10:36 PM, Matthew Wilcox wrote:
On Tue, May 17, 2022 at 08:55:49PM +0800, Xiubo Li wrote:
+int ceph_wait_on_conflict_unlink(struct dentry *dentry)
+{
+ struct ceph_fs_client *fsc = ceph_sb_to_client(dentry->d_sb);
+ struct dentry *pdentry = dentry->d_parent;
+ struct dentry *udentry, *found = NULL;
+ struct ceph_dentry_info *di;
+ struct qstr dname;
+ u32 hash = dentry->d_name.hash;
+ int err;
+
+ dname.name = dentry->d_name.name;
+ dname.len = dentry->d_name.len;
+
+ rcu_read_lock();
+ hash_for_each_possible_rcu(fsc->async_unlink_conflict, di,
+ hnode, hash) {
+ udentry = di->dentry;
+
+ spin_lock(&udentry->d_lock);
+ if (udentry->d_name.hash != hash)
+ goto next;
+ if (unlikely(udentry->d_parent != pdentry))
+ goto next;
+ if (!hash_hashed(&di->hnode))
+ goto next;
+
+ if (!test_bit(CEPH_DENTRY_ASYNC_UNLINK_BIT, &di->flags))
+ pr_warn("%s dentry %p:%pd async unlink bit is not set\n",
+ __func__, dentry, dentry);
+
+ if (d_compare(pdentry, udentry, &dname))
+ goto next;
+
+ spin_unlock(&udentry->d_lock);
+ found = dget(udentry);
+ break;
+next:
+ spin_unlock(&udentry->d_lock);
+ }
+ rcu_read_unlock();
+
+ if (likely(!found))
+ return 0;
+
+ dout("%s dentry %p:%pd conflict with old %p:%pd\n", __func__,
+ dentry, dentry, found, found);
+
+ err = wait_on_bit(&di->flags, CEPH_DENTRY_ASYNC_UNLINK_BIT,
+ TASK_INTERRUPTIBLE);
Do you really want to use TASK_INTERRUPTIBLE here? If the window is
resized and you get a SIGWINCH, or a timer goes off and you get a
SIGALRM, you want to return -EINTR? I would suggest that TASK_KILLABLE
is probably the semantics that you want.
Sounds reasonable. I will switch to use the TASK_KILLABLE.
@Jeff
I just copied this code from ceph_wait_on_async_create(). BTW, do we
have any other consideration that we must use the TASK_INTERRUPTIBLE there ?
Thanks.
-- Xiubo
