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-rw-r--r--fs/nfsd/filecache.c88
1 files changed, 29 insertions, 59 deletions
diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
index d5c57360b418..29a62db155fb 100644
--- a/fs/nfsd/filecache.c
+++ b/fs/nfsd/filecache.c
@@ -405,22 +405,15 @@ nfsd_file_unhash(struct nfsd_file *nf)
return false;
}
-/*
- * Return true if the file was unhashed.
- */
-static bool
+static void
nfsd_file_unhash_and_dispose(struct nfsd_file *nf, struct list_head *dispose)
{
trace_nfsd_file_unhash_and_dispose(nf);
- if (!nfsd_file_unhash(nf))
- return false;
- /* keep final reference for nfsd_file_lru_dispose */
- if (refcount_dec_not_one(&nf->nf_ref))
- return true;
-
- nfsd_file_lru_remove(nf);
- list_add(&nf->nf_lru, dispose);
- return true;
+ if (nfsd_file_unhash(nf)) {
+ /* caller must call nfsd_file_dispose_list() later */
+ nfsd_file_lru_remove(nf);
+ list_add(&nf->nf_lru, dispose);
+ }
}
static void
@@ -562,8 +555,6 @@ nfsd_file_dispose_list_delayed(struct list_head *dispose)
* @lock: LRU list lock (unused)
* @arg: dispose list
*
- * Note this can deadlock with nfsd_file_cache_purge.
- *
* Return values:
* %LRU_REMOVED: @item was removed from the LRU
* %LRU_ROTATE: @item is to be moved to the LRU tail
@@ -748,8 +739,6 @@ nfsd_file_close_inode(struct inode *inode)
*
* Walk the LRU list and close any entries that have not been used since
* the last scan.
- *
- * Note this can deadlock with nfsd_file_cache_purge.
*/
static void
nfsd_file_delayed_close(struct work_struct *work)
@@ -891,16 +880,12 @@ out_err:
goto out;
}
-/*
- * Note this can deadlock with nfsd_file_lru_cb.
- */
static void
__nfsd_file_cache_purge(struct net *net)
{
struct rhashtable_iter iter;
struct nfsd_file *nf;
LIST_HEAD(dispose);
- bool del;
rhashtable_walk_enter(&nfsd_file_rhash_tbl, &iter);
do {
@@ -910,14 +895,7 @@ __nfsd_file_cache_purge(struct net *net)
while (!IS_ERR_OR_NULL(nf)) {
if (net && nf->nf_net != net)
continue;
- del = nfsd_file_unhash_and_dispose(nf, &dispose);
-
- /*
- * Deadlock detected! Something marked this entry as
- * unhased, but hasn't removed it from the hash list.
- */
- WARN_ON_ONCE(!del);
-
+ nfsd_file_unhash_and_dispose(nf, &dispose);
nf = rhashtable_walk_next(&iter);
}
@@ -1064,9 +1042,10 @@ nfsd_file_do_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp,
.need = may_flags & NFSD_FILE_MAY_MASK,
.net = SVC_NET(rqstp),
};
- struct nfsd_file *nf, *new;
- bool retry = true;
+ bool open_retry = true;
+ struct nfsd_file *nf;
__be32 status;
+ int ret;
status = fh_verify(rqstp, fhp, S_IFREG,
may_flags|NFSD_MAY_OWNER_OVERRIDE);
@@ -1076,35 +1055,33 @@ nfsd_file_do_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp,
key.cred = get_current_cred();
retry:
- /* Avoid allocation if the item is already in cache */
- nf = rhashtable_lookup_fast(&nfsd_file_rhash_tbl, &key,
- nfsd_file_rhash_params);
+ rcu_read_lock();
+ nf = rhashtable_lookup(&nfsd_file_rhash_tbl, &key,
+ nfsd_file_rhash_params);
if (nf)
nf = nfsd_file_get(nf);
+ rcu_read_unlock();
if (nf)
goto wait_for_construction;
- new = nfsd_file_alloc(&key, may_flags);
- if (!new) {
+ nf = nfsd_file_alloc(&key, may_flags);
+ if (!nf) {
status = nfserr_jukebox;
goto out_status;
}
- nf = rhashtable_lookup_get_insert_key(&nfsd_file_rhash_tbl,
- &key, &new->nf_rhash,
- nfsd_file_rhash_params);
- if (!nf) {
- nf = new;
- goto open_file;
- }
- if (IS_ERR(nf))
- goto insert_err;
- nf = nfsd_file_get(nf);
- if (nf == NULL) {
- nf = new;
+ ret = rhashtable_lookup_insert_key(&nfsd_file_rhash_tbl,
+ &key, &nf->nf_rhash,
+ nfsd_file_rhash_params);
+ if (likely(ret == 0))
goto open_file;
- }
- nfsd_file_slab_free(&new->nf_rcu);
+
+ nfsd_file_slab_free(&nf->nf_rcu);
+ if (ret == -EEXIST)
+ goto retry;
+ trace_nfsd_file_insert_err(rqstp, key.inode, may_flags, ret);
+ status = nfserr_jukebox;
+ goto out_status;
wait_for_construction:
wait_on_bit(&nf->nf_flags, NFSD_FILE_PENDING, TASK_UNINTERRUPTIBLE);
@@ -1112,11 +1089,11 @@ wait_for_construction:
/* Did construction of this file fail? */
if (!test_bit(NFSD_FILE_HASHED, &nf->nf_flags)) {
trace_nfsd_file_cons_err(rqstp, key.inode, may_flags, nf);
- if (!retry) {
+ if (!open_retry) {
status = nfserr_jukebox;
goto out;
}
- retry = false;
+ open_retry = false;
nfsd_file_put_noref(nf);
goto retry;
}
@@ -1164,13 +1141,6 @@ open_file:
smp_mb__after_atomic();
wake_up_bit(&nf->nf_flags, NFSD_FILE_PENDING);
goto out;
-
-insert_err:
- nfsd_file_slab_free(&new->nf_rcu);
- trace_nfsd_file_insert_err(rqstp, key.inode, may_flags, PTR_ERR(nf));
- nf = NULL;
- status = nfserr_jukebox;
- goto out_status;
}
/**