| Message ID | 99f0c881-f7bc-e548-8694-c68f11afde68@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, Feb 08 2017, Kinglong Mee wrote: > User always free the cache_detail after sunrpc_destroy_cache_detail(), > so, it must cleanup up entries that left in the cache_detail, > otherwise, NULL reference may be caused when using the left entries. > > Also, NeriBrown suggests "write a stand-alone cache_purge()." > > v3, move the cache_fresh_unlocked() out of write lock, > v2, a stand-alone cache_purge(), not only for sunrpc_destroy_cache_detail > > Signed-off-by: Kinglong Mee <kinglongmee@gmail.com> Looks good to me. Reviewed-by: NeilBrown <neilb@suse.com> Thanks, NeilBrown > --- > net/sunrpc/cache.c | 41 ++++++++++++++++++++++++++--------------- > 1 file changed, 26 insertions(+), 15 deletions(-) > > diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c > index 8147e8d..f0a7390 100644 > --- a/net/sunrpc/cache.c > +++ b/net/sunrpc/cache.c > @@ -362,11 +362,6 @@ void sunrpc_destroy_cache_detail(struct cache_detail *cd) > cache_purge(cd); > spin_lock(&cache_list_lock); > write_lock(&cd->hash_lock); > - if (cd->entries) { > - write_unlock(&cd->hash_lock); > - spin_unlock(&cache_list_lock); > - goto out; > - } > if (current_detail == cd) > current_detail = NULL; > list_del_init(&cd->others); > @@ -376,9 +371,6 @@ void sunrpc_destroy_cache_detail(struct cache_detail *cd) > /* module must be being unloaded so its safe to kill the worker */ > cancel_delayed_work_sync(&cache_cleaner); > } > - return; > -out: > - printk(KERN_ERR "RPC: failed to unregister %s cache\n", cd->name); > } > EXPORT_SYMBOL_GPL(sunrpc_destroy_cache_detail); > > @@ -497,13 +489,32 @@ EXPORT_SYMBOL_GPL(cache_flush); > > void cache_purge(struct cache_detail *detail) > { > - time_t now = seconds_since_boot(); > - if (detail->flush_time >= now) > - now = detail->flush_time + 1; > - /* 'now' is the maximum value any 'last_refresh' can have */ > - detail->flush_time = now; > - detail->nextcheck = seconds_since_boot(); > - cache_flush(); > + struct cache_head *ch = NULL; > + struct hlist_head *head = NULL; > + struct hlist_node *tmp = NULL; > + int i = 0; > + > + write_lock(&detail->hash_lock); > + if (!detail->entries) { > + write_unlock(&detail->hash_lock); > + return; > + } > + > + dprintk("RPC: %d entries in %s cache\n", detail->entries, detail->name); > + for (i = 0; i < detail->hash_size; i++) { > + head = &detail->hash_table[i]; > + hlist_for_each_entry_safe(ch, tmp, head, cache_list) { > + hlist_del_init(&ch->cache_list); > + detail->entries--; > + > + set_bit(CACHE_CLEANED, &ch->flags); > + write_unlock(&detail->hash_lock); > + cache_fresh_unlocked(ch, detail); > + cache_put(ch, detail); > + write_lock(&detail->hash_lock); > + } > + } > + write_unlock(&detail->hash_lock); > } > EXPORT_SYMBOL_GPL(cache_purge); > > -- > 2.9.3 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-nfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c index 8147e8d..f0a7390 100644 --- a/net/sunrpc/cache.c +++ b/net/sunrpc/cache.c @@ -362,11 +362,6 @@ void sunrpc_destroy_cache_detail(struct cache_detail *cd) cache_purge(cd); spin_lock(&cache_list_lock); write_lock(&cd->hash_lock); - if (cd->entries) { - write_unlock(&cd->hash_lock); - spin_unlock(&cache_list_lock); - goto out; - } if (current_detail == cd) current_detail = NULL; list_del_init(&cd->others); @@ -376,9 +371,6 @@ void sunrpc_destroy_cache_detail(struct cache_detail *cd) /* module must be being unloaded so its safe to kill the worker */ cancel_delayed_work_sync(&cache_cleaner); } - return; -out: - printk(KERN_ERR "RPC: failed to unregister %s cache\n", cd->name); } EXPORT_SYMBOL_GPL(sunrpc_destroy_cache_detail); @@ -497,13 +489,32 @@ EXPORT_SYMBOL_GPL(cache_flush); void cache_purge(struct cache_detail *detail) { - time_t now = seconds_since_boot(); - if (detail->flush_time >= now) - now = detail->flush_time + 1; - /* 'now' is the maximum value any 'last_refresh' can have */ - detail->flush_time = now; - detail->nextcheck = seconds_since_boot(); - cache_flush(); + struct cache_head *ch = NULL; + struct hlist_head *head = NULL; + struct hlist_node *tmp = NULL; + int i = 0; + + write_lock(&detail->hash_lock); + if (!detail->entries) { + write_unlock(&detail->hash_lock); + return; + } + + dprintk("RPC: %d entries in %s cache\n", detail->entries, detail->name); + for (i = 0; i < detail->hash_size; i++) { + head = &detail->hash_table[i]; + hlist_for_each_entry_safe(ch, tmp, head, cache_list) { + hlist_del_init(&ch->cache_list); + detail->entries--; + + set_bit(CACHE_CLEANED, &ch->flags); + write_unlock(&detail->hash_lock); + cache_fresh_unlocked(ch, detail); + cache_put(ch, detail); + write_lock(&detail->hash_lock); + } + } + write_unlock(&detail->hash_lock); } EXPORT_SYMBOL_GPL(cache_purge);
User always free the cache_detail after sunrpc_destroy_cache_detail(), so, it must cleanup up entries that left in the cache_detail, otherwise, NULL reference may be caused when using the left entries. Also, NeriBrown suggests "write a stand-alone cache_purge()." v3, move the cache_fresh_unlocked() out of write lock, v2, a stand-alone cache_purge(), not only for sunrpc_destroy_cache_detail Signed-off-by: Kinglong Mee <kinglongmee@gmail.com> --- net/sunrpc/cache.c | 41 ++++++++++++++++++++++++++--------------- 1 file changed, 26 insertions(+), 15 deletions(-)