From: Roberto Bergantinos Corpas <rbergant@redhat.com>
To: bfields@fieldses.org
Cc: linux-nfs@vger.kernel.org
Subject: [PATCH] sunrpc: clean-up cache downcall
Date: Fri, 27 Nov 2020 17:14:51 +0100 [thread overview]
Message-ID: <20201127161451.17922-1-rbergant@redhat.com> (raw)
We can simplifly code around cache_downcall unifying memory
allocations using kvmalloc, this have the benefit of getting rid of
cache_slow_downcall (and queue_io_mutex), and also matches userland
allocation size and limits
Signed-off-by: Roberto Bergantinos Corpas <rbergant@redhat.com>
---
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
next reply other threads:[~2020-11-27 16:15 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-27 16:14 Roberto Bergantinos Corpas [this message]
2020-11-27 16:50 ` [PATCH] sunrpc: clean-up cache downcall Chuck Lever
2020-11-27 17:14 ` Roberto Bergantinos Corpas
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20201127161451.17922-1-rbergant@redhat.com \
--to=rbergant@redhat.com \
--cc=bfields@fieldses.org \
--cc=linux-nfs@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.