fuse: rework fuse_perform_write()

The patch allocates as many page pointers in fuse_req as needed to cover
interval [pos .. pos+len-1]. Inline helper fuse_wr_pages() is introduced
to hide this cumbersome arithmetic.

Signed-off-by: Maxim Patlasov <mpatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
This commit is contained in:
Maxim Patlasov 2012-10-26 19:49:00 +04:00 committed by Miklos Szeredi
parent f8dbdf8182
commit d07f09f509
1 changed files with 11 additions and 2 deletions

View File

@ -881,11 +881,19 @@ static ssize_t fuse_fill_write_pages(struct fuse_req *req,
if (!fc->big_writes)
break;
} while (iov_iter_count(ii) && count < fc->max_write &&
req->num_pages < FUSE_MAX_PAGES_PER_REQ && offset == 0);
req->num_pages < req->max_pages && offset == 0);
return count > 0 ? count : err;
}
static inline unsigned fuse_wr_pages(loff_t pos, size_t len)
{
return min_t(unsigned,
((pos + len - 1) >> PAGE_CACHE_SHIFT) -
(pos >> PAGE_CACHE_SHIFT) + 1,
FUSE_MAX_PAGES_PER_REQ);
}
static ssize_t fuse_perform_write(struct file *file,
struct address_space *mapping,
struct iov_iter *ii, loff_t pos)
@ -901,8 +909,9 @@ static ssize_t fuse_perform_write(struct file *file,
do {
struct fuse_req *req;
ssize_t count;
unsigned nr_pages = fuse_wr_pages(pos, iov_iter_count(ii));
req = fuse_get_req(fc, FUSE_MAX_PAGES_PER_REQ);
req = fuse_get_req(fc, nr_pages);
if (IS_ERR(req)) {
err = PTR_ERR(req);
break;