This patch adds recall_lock hold to nfsd_forget_delegations() to protect
nfsd_process_n_delegations() call.
Also, looks like it would be better to collect delegations to some local
on-stack list, and then unhash collected list. This split allows to simplify
locking, because delegation traversing is protected by recall_lock, when
delegation unhash is protected by client_mutex.
Signed-off-by: Stanislav Kinsbursky <skinsbursky@xxxxxxxxxxxxx>
---
fs/nfsd/nfs4state.c | 32 ++++++++++++++++++++++++--------
1 files changed, 24 insertions(+), 8 deletions(-)
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 21266c7..f004e61 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -2597,7 +2597,7 @@ out:
return ret;
}
-static void nfsd_break_one_deleg(struct nfs4_delegation *dp)
+static void nfsd_break_one_deleg(struct nfs4_delegation *dp, void *data)
{
/* We're assuming the state code never drops its reference
* without first removing the lease. Since we're in this lease
@@ -2633,7 +2633,7 @@ static void nfsd_break_deleg_cb(struct file_lock *fl)
spin_lock(&recall_lock);
fp->fi_had_conflict = true;
list_for_each_entry(dp, &fp->fi_delegations, dl_perfile)
- nfsd_break_one_deleg(dp);
+ nfsd_break_one_deleg(dp, NULL);
spin_unlock(&recall_lock);
}
@@ -4694,7 +4694,7 @@ void nfsd_forget_openowners(u64 num)
printk(KERN_INFO "NFSD: Forgot %d open owners", count);
}
-int nfsd_process_n_delegations(u64 num, void (*deleg_func)(struct nfs4_delegation *))
+int nfsd_process_n_delegations(u64 num, void (*deleg_func)(struct nfs4_delegation *, void *), void *data)
{
int i, count = 0;
struct nfs4_file *fp, *fnext;
@@ -4703,7 +4703,7 @@ int nfsd_process_n_delegations(u64 num, void (*deleg_func)(struct nfs4_delegatio
for (i = 0; i < FILE_HASH_SIZE; i++) {
list_for_each_entry_safe(fp, fnext, &file_hashtbl[i], fi_hash) {
list_for_each_entry_safe(dp, dnext, &fp->fi_delegations, dl_perfile) {
- deleg_func(dp);
+ deleg_func(dp, data);
if (++count == num)
return count;
}
@@ -4713,15 +4713,31 @@ int nfsd_process_n_delegations(u64 num, void (*deleg_func)(struct nfs4_delegatio
return count;
}
+/* Called under the recall_lock spinlock. */
+static void
+collect_delegation(struct nfs4_delegation *dp, void *data)
+{
+ struct list_head *list = data;
+
+ list_move(&dp->dl_perfile, list);
+}
+
void nfsd_forget_delegations(u64 num)
{
unsigned int count;
+ struct nfs4_delegation *dp, *dnext;
+ LIST_HEAD(unhash_list);
- nfs4_lock_state();
- count = nfsd_process_n_delegations(num, unhash_delegation);
- nfs4_unlock_state();
+ spin_lock(&recall_lock);
+ count = nfsd_process_n_delegations(num, collect_delegation, &unhash_list);
+ spin_unlock(&recall_lock);
printk(KERN_INFO "NFSD: Forgot %d delegations", count);
+
+ nfs4_lock_state();
+ list_for_each_entry_safe(dp, dnext, &unhash_list, dl_perfile)
+ unhash_delegation(dp);
+ nfs4_unlock_state();
}
void nfsd_recall_delegations(u64 num)
@@ -4730,7 +4746,7 @@ void nfsd_recall_delegations(u64 num)
nfs4_lock_state();
spin_lock(&recall_lock);
- count = nfsd_process_n_delegations(num, nfsd_break_one_deleg);
+ count = nfsd_process_n_delegations(num, nfsd_break_one_deleg, NULL);
spin_unlock(&recall_lock);
nfs4_unlock_state();
--
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