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authorStanislav Kinsbursky <skinsbursky@parallels.com>2012-05-25 18:38:50 +0400
committerJ. Bruce Fields <bfields@redhat.com>2012-07-25 09:18:27 -0400
commita6d88f293ecd1b7444e128777f4a893e7a998852 (patch)
treecb8e65d7b24192bc8cdbe2afa4aad506c0e99db7 /fs/nfsd
parent5559b50acdcdcad7e362882d3261bf934c9436f6 (diff)
NFSd: fix locking in nfsd_forget_delegations()
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@parallels.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Diffstat (limited to 'fs/nfsd')
-rw-r--r--fs/nfsd/nfs4state.c23
1 files changed, 17 insertions, 6 deletions
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index fe96015fbfc..d10ad8bc47a 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -4575,7 +4575,7 @@ 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, struct list_head *list)
{
int i, count = 0;
struct nfs4_file *fp, *fnext;
@@ -4584,7 +4584,7 @@ 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);
+ list_move(&dp->dl_recall_lru, list);
if (++count == num)
return count;
}
@@ -4597,9 +4597,16 @@ int nfsd_process_n_delegations(u64 num, void (*deleg_func)(struct nfs4_delegatio
void nfsd_forget_delegations(u64 num)
{
unsigned int count;
+ LIST_HEAD(victims);
+ struct nfs4_delegation *dp, *dnext;
+
+ spin_lock(&recall_lock);
+ count = nfsd_process_n_delegations(num, &victims);
+ spin_unlock(&recall_lock);
nfs4_lock_state();
- count = nfsd_process_n_delegations(num, unhash_delegation);
+ list_for_each_entry_safe(dp, dnext, &victims, dl_recall_lru)
+ unhash_delegation(dp);
nfs4_unlock_state();
printk(KERN_INFO "NFSD: Forgot %d delegations", count);
@@ -4608,12 +4615,16 @@ void nfsd_forget_delegations(u64 num)
void nfsd_recall_delegations(u64 num)
{
unsigned int count;
+ LIST_HEAD(victims);
+ struct nfs4_delegation *dp, *dnext;
- nfs4_lock_state();
spin_lock(&recall_lock);
- count = nfsd_process_n_delegations(num, nfsd_break_one_deleg);
+ count = nfsd_process_n_delegations(num, &victims);
+ list_for_each_entry_safe(dp, dnext, &victims, dl_recall_lru) {
+ list_del(&dp->dl_recall_lru);
+ nfsd_break_one_deleg(dp);
+ }
spin_unlock(&recall_lock);
- nfs4_unlock_state();
printk(KERN_INFO "NFSD: Recalled %d delegations", count);
}