From bed9da0213f2174719b68012bd60735a11cfe244 Mon Sep 17 00:00:00 2001 From: Pavel Shilovsky Date: Wed, 25 Jun 2014 11:28:57 +0400 Subject: CIFS: Use multicredits for SMB 2.1/3 reads If we negotiate SMB 2.1 and higher version of the protocol and a server supports large read buffer size, we need to consume 1 credit per 65536 bytes. So, we need to know how many credits we have and obtain the required number of them before constructing a readdata structure in readpages and user read. Reviewed-by: Shirish Pargaonkar Signed-off-by: Pavel Shilovsky Signed-off-by: Steve French --- fs/cifs/file.c | 35 ++++++++++++++++++++++++++++------- 1 file changed, 28 insertions(+), 7 deletions(-) (limited to 'fs/cifs/file.c') diff --git a/fs/cifs/file.c b/fs/cifs/file.c index 00b2a254ff1..ebdeb56f8d3 100644 --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -2917,7 +2917,7 @@ cifs_send_async_read(loff_t offset, size_t len, struct cifsFileInfo *open_file, struct cifs_sb_info *cifs_sb, struct list_head *rdata_list) { struct cifs_readdata *rdata; - unsigned int npages; + unsigned int npages, rsize, credits; size_t cur_len; int rc; pid_t pid; @@ -2931,13 +2931,19 @@ cifs_send_async_read(loff_t offset, size_t len, struct cifsFileInfo *open_file, pid = current->tgid; do { - cur_len = min_t(const size_t, len, cifs_sb->rsize); + rc = server->ops->wait_mtu_credits(server, cifs_sb->rsize, + &rsize, &credits); + if (rc) + break; + + cur_len = min_t(const size_t, len, rsize); npages = DIV_ROUND_UP(cur_len, PAGE_SIZE); /* allocate a readdata struct */ rdata = cifs_readdata_alloc(npages, cifs_uncached_readv_complete); if (!rdata) { + add_credits_and_wake_if(server, credits, 0); rc = -ENOMEM; break; } @@ -2953,12 +2959,14 @@ cifs_send_async_read(loff_t offset, size_t len, struct cifsFileInfo *open_file, rdata->pid = pid; rdata->pagesz = PAGE_SIZE; rdata->read_into_pages = cifs_uncached_read_into_pages; + rdata->credits = credits; if (!rdata->cfile->invalidHandle || !cifs_reopen_file(rdata->cfile, true)) rc = server->ops->async_readv(rdata); error: if (rc) { + add_credits_and_wake_if(server, rdata->credits, 0); kref_put(&rdata->refcount, cifs_uncached_readdata_release); if (rc == -EAGAIN) @@ -3458,10 +3466,16 @@ static int cifs_readpages(struct file *file, struct address_space *mapping, * the rdata->pages, then we want them in increasing order. */ while (!list_empty(page_list)) { - unsigned int i, nr_pages, bytes; + unsigned int i, nr_pages, bytes, rsize; loff_t offset; struct page *page, *tpage; struct cifs_readdata *rdata; + unsigned credits; + + rc = server->ops->wait_mtu_credits(server, cifs_sb->rsize, + &rsize, &credits); + if (rc) + break; /* * Give up immediately if rsize is too small to read an entire @@ -3469,13 +3483,17 @@ static int cifs_readpages(struct file *file, struct address_space *mapping, * reach this point however since we set ra_pages to 0 when the * rsize is smaller than a cache page. */ - if (unlikely(cifs_sb->rsize < PAGE_CACHE_SIZE)) + if (unlikely(rsize < PAGE_CACHE_SIZE)) { + add_credits_and_wake_if(server, credits, 0); return 0; + } - rc = readpages_get_pages(mapping, page_list, cifs_sb->rsize, - &tmplist, &nr_pages, &offset, &bytes); - if (rc) + rc = readpages_get_pages(mapping, page_list, rsize, &tmplist, + &nr_pages, &offset, &bytes); + if (rc) { + add_credits_and_wake_if(server, credits, 0); break; + } rdata = cifs_readdata_alloc(nr_pages, cifs_readv_complete); if (!rdata) { @@ -3487,6 +3505,7 @@ static int cifs_readpages(struct file *file, struct address_space *mapping, page_cache_release(page); } rc = -ENOMEM; + add_credits_and_wake_if(server, credits, 0); break; } @@ -3497,6 +3516,7 @@ static int cifs_readpages(struct file *file, struct address_space *mapping, rdata->pid = pid; rdata->pagesz = PAGE_CACHE_SIZE; rdata->read_into_pages = cifs_readpages_read_into_pages; + rdata->credits = credits; list_for_each_entry_safe(page, tpage, &tmplist, lru) { list_del(&page->lru); @@ -3507,6 +3527,7 @@ static int cifs_readpages(struct file *file, struct address_space *mapping, !cifs_reopen_file(rdata->cfile, true)) rc = server->ops->async_readv(rdata); if (rc) { + add_credits_and_wake_if(server, rdata->credits, 0); for (i = 0; i < rdata->nr_pages; i++) { page = rdata->pages[i]; lru_cache_add_file(page); -- cgit v1.2.3-70-g09d2