Hi Bruce! Thanks for comments!, i'll send a v2 with mechanical errors fixed based on v5.10-rc5. rgds roberto On Fri, Nov 27, 2020 at 5:52 PM Chuck Lever <chuck.lever@xxxxxxxxxx> wrote: > > Hi Roberto- > > I spotted some mechanical problems. > > > > On Nov 27, 2020, at 11:14 AM, Roberto Bergantinos Corpas <rbergant@xxxxxxxxxx> wrote: > > > > We can simplifly code around cache_downcall unifying memory > > ^simplifly^simplify > > > allocations using kvmalloc, this have the benefit of getting rid of > > ^, this have^. This has > > > cache_slow_downcall (and queue_io_mutex), and also matches userland > > allocation size and limits > > > > Signed-off-by: Roberto Bergantinos Corpas <rbergant@xxxxxxxxxx> > > Assuming Bruce is copacetic with this patch, the change looks > appropriate for the v5.11 merge window. However, this patch > doesn't appear to apply to v5.10-rc5. Might be because > 27a1e8a0f79e ("sunrpc: raise kernel RPC channel buffer size") > was already merged? > > > > --- > > net/sunrpc/cache.c | 41 +++++++++++------------------------------ > > 1 file changed, 11 insertions(+), 30 deletions(-) > > > > diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c > > index baef5ee43dbb..1347ecae9c84 100644 > > --- a/net/sunrpc/cache.c > > +++ b/net/sunrpc/cache.c > > @@ -777,7 +777,6 @@ void cache_clean_deferred(void *owner) > > */ > > > > static DEFINE_SPINLOCK(queue_lock); > > -static DEFINE_MUTEX(queue_io_mutex); > > > > struct cache_queue { > > struct list_head list; > > @@ -905,44 +904,26 @@ static ssize_t cache_do_downcall(char *kaddr, const char __user *buf, > > return ret; > > } > > > > -static ssize_t cache_slow_downcall(const char __user *buf, > > - size_t count, struct cache_detail *cd) > > -{ > > - static char write_buf[8192]; /* protected by queue_io_mutex */ > > - ssize_t ret = -EINVAL; > > - > > - if (count >= sizeof(write_buf)) > > - goto out; > > - mutex_lock(&queue_io_mutex); > > - ret = cache_do_downcall(write_buf, buf, count, cd); > > - mutex_unlock(&queue_io_mutex); > > -out: > > - return ret; > > -} > > - > > static ssize_t cache_downcall(struct address_space *mapping, > > const char __user *buf, > > size_t count, struct cache_detail *cd) > > { > > - struct page *page; > > - char *kaddr; > > + char *write_buf; > > ssize_t ret = -ENOMEM; > > > > - if (count >= PAGE_SIZE) > > - goto out_slow; > > + if (count >= 32768) { /* 32k is max userland buffer, lets check anyway */ > > + ret = -EINVAL; > > + goto out; > > + } > > > > - page = find_or_create_page(mapping, 0, GFP_KERNEL); > > - if (!page) > > - goto out_slow; > > + write_buf = kvmalloc(count + 1, GFP_KERNEL); > > + if (!write_buf) > > + goto out; > > > > - kaddr = kmap(page); > > - ret = cache_do_downcall(kaddr, buf, count, cd); > > - kunmap(page); > > - unlock_page(page); > > - put_page(page); > > + ret = cache_do_downcall(write_buf, buf, count, cd); > > + kvfree(write_buf); > > +out: > > return ret; > > -out_slow: > > - return cache_slow_downcall(buf, count, cd); > > } > > > > static ssize_t cache_write(struct file *filp, const char __user *buf, > > -- > > 2.21.0 > > > > -- > Chuck Lever > > >