diff options
| -rw-r--r-- | net/sunrpc/cache.c | 95 |
1 files changed, 70 insertions, 25 deletions
diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c index 062d4f4307e..c8e7d2d0726 100644 --- a/net/sunrpc/cache.c +++ b/net/sunrpc/cache.c @@ -27,6 +27,7 @@ #include <linux/net.h> #include <linux/workqueue.h> #include <linux/mutex.h> +#include <linux/pagemap.h> #include <asm/ioctls.h> #include <linux/sunrpc/types.h> #include <linux/sunrpc/cache.h> @@ -702,13 +703,14 @@ cache_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos) { struct cache_reader *rp = filp->private_data; struct cache_request *rq; - struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data; + struct inode *inode = filp->f_path.dentry->d_inode; + struct cache_detail *cd = PDE(inode)->data; int err; if (count == 0) return 0; - mutex_lock(&queue_io_mutex); /* protect against multiple concurrent + mutex_lock(&inode->i_mutex); /* protect against multiple concurrent * readers on this file */ again: spin_lock(&queue_lock); @@ -721,7 +723,7 @@ cache_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos) } if (rp->q.list.next == &cd->queue) { spin_unlock(&queue_lock); - mutex_unlock(&queue_io_mutex); + mutex_unlock(&inode->i_mutex); BUG_ON(rp->offset); return 0; } @@ -768,38 +770,81 @@ cache_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos) } if (err == -EAGAIN) goto again; - mutex_unlock(&queue_io_mutex); + mutex_unlock(&inode->i_mutex); return err ? err : count; } -static char write_buf[8192]; /* protected by queue_io_mutex */ +static ssize_t cache_do_downcall(char *kaddr, const char __user *buf, + size_t count, struct cache_detail *cd) +{ + ssize_t ret; -static ssize_t -cache_write(struct file *filp, const char __user *buf, size_t count, - loff_t *ppos) + if (copy_from_user(kaddr, buf, count)) + return -EFAULT; + kaddr[count] = '\0'; + ret = cd->cache_parse(cd, kaddr, count); + if (!ret) + ret = count; + return ret; +} + +static ssize_t cache_slow_downcall(const char __user *buf, + size_t count, struct cache_detail *cd) { - int err; - struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data; + static char write_buf[8192]; /* protected by queue_io_mutex */ + ssize_t ret = -EINVAL; - if (count == 0) - return 0; if (count >= sizeof(write_buf)) - return -EINVAL; - + goto out; mutex_lock(&queue_io_mutex); + ret = cache_do_downcall(write_buf, buf, count, cd); + mutex_unlock(&queue_io_mutex); +out: + return ret; +} - if (copy_from_user(write_buf, buf, count)) { - mutex_unlock(&queue_io_mutex); - return -EFAULT; - } - write_buf[count] = '\0'; - if (cd->cache_parse) - err = cd->cache_parse(cd, write_buf, count); - else - err = -EINVAL; +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; + ssize_t ret = -ENOMEM; + + if (count >= PAGE_CACHE_SIZE) + goto out_slow; + + page = find_or_create_page(mapping, 0, GFP_KERNEL); + if (!page) + goto out_slow; + + kaddr = kmap(page); + ret = cache_do_downcall(kaddr, buf, count, cd); + kunmap(page); + unlock_page(page); + page_cache_release(page); + return ret; +out_slow: + return cache_slow_downcall(buf, count, cd); +} - mutex_unlock(&queue_io_mutex); - return err ? err : count; +static ssize_t +cache_write(struct file *filp, const char __user *buf, size_t count, + loff_t *ppos) +{ + struct address_space *mapping = filp->f_mapping; + struct inode *inode = filp->f_path.dentry->d_inode; + struct cache_detail *cd = PDE(inode)->data; + ssize_t ret = -EINVAL; + + if (!cd->cache_parse) + goto out; + + mutex_lock(&inode->i_mutex); + ret = cache_downcall(mapping, buf, count, cd); + mutex_unlock(&inode->i_mutex); +out: + return ret; } static DECLARE_WAIT_QUEUE_HEAD(queue_wait); |