From 1dbe3466b4d26078d907c64e2b68faed5dc58854 Mon Sep 17 00:00:00 2001 From: Long Li Date: Wed, 30 May 2018 12:47:55 -0700 Subject: CIFS: Use offset when reading pages With offset defined in rdata, transport functions need to look at this offset when reading data into the correct places in pages. Signed-off-by: Long Li Signed-off-by: Steve French --- fs/cifs/file.c | 52 +++++++++++++++++++++++++++++++++++++--------------- 1 file changed, 37 insertions(+), 15 deletions(-) (limited to 'fs/cifs/file.c') diff --git a/fs/cifs/file.c b/fs/cifs/file.c index 1c98293c1829..87eece6fbd48 100644 --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -3026,12 +3026,20 @@ uncached_fill_pages(struct TCP_Server_Info *server, int result = 0; unsigned int i; unsigned int nr_pages = rdata->nr_pages; + unsigned int page_offset = rdata->page_offset; rdata->got_bytes = 0; rdata->tailsz = PAGE_SIZE; for (i = 0; i < nr_pages; i++) { struct page *page = rdata->pages[i]; size_t n; + unsigned int segment_size = rdata->pagesz; + + if (i == 0) + segment_size -= page_offset; + else + page_offset = 0; + if (len <= 0) { /* no need to hold page hostage */ @@ -3040,24 +3048,25 @@ uncached_fill_pages(struct TCP_Server_Info *server, put_page(page); continue; } + n = len; - if (len >= PAGE_SIZE) { + if (len >= segment_size) /* enough data to fill the page */ - n = PAGE_SIZE; - len -= n; - } else { - zero_user(page, len, PAGE_SIZE - len); + n = segment_size; + else rdata->tailsz = len; - len = 0; - } + len -= n; + if (iter) - result = copy_page_from_iter(page, 0, n, iter); + result = copy_page_from_iter( + page, page_offset, n, iter); #ifdef CONFIG_CIFS_SMB_DIRECT else if (rdata->mr) result = n; #endif else - result = cifs_read_page_from_socket(server, page, n); + result = cifs_read_page_from_socket( + server, page, page_offset, n); if (result < 0) break; @@ -3130,6 +3139,7 @@ cifs_send_async_read(loff_t offset, size_t len, struct cifsFileInfo *open_file, rdata->bytes = cur_len; rdata->pid = pid; rdata->pagesz = PAGE_SIZE; + rdata->tailsz = PAGE_SIZE; rdata->read_into_pages = cifs_uncached_read_into_pages; rdata->copy_into_pages = cifs_uncached_copy_into_pages; rdata->credits = credits; @@ -3574,6 +3584,7 @@ readpages_fill_pages(struct TCP_Server_Info *server, u64 eof; pgoff_t eof_index; unsigned int nr_pages = rdata->nr_pages; + unsigned int page_offset = rdata->page_offset; /* determine the eof that the server (probably) has */ eof = CIFS_I(rdata->mapping->host)->server_eof; @@ -3584,13 +3595,21 @@ readpages_fill_pages(struct TCP_Server_Info *server, rdata->tailsz = PAGE_SIZE; for (i = 0; i < nr_pages; i++) { struct page *page = rdata->pages[i]; - size_t n = PAGE_SIZE; + unsigned int to_read = rdata->pagesz; + size_t n; + + if (i == 0) + to_read -= page_offset; + else + page_offset = 0; + + n = to_read; - if (len >= PAGE_SIZE) { - len -= PAGE_SIZE; + if (len >= to_read) { + len -= to_read; } else if (len > 0) { /* enough for partial page, fill and zero the rest */ - zero_user(page, len, PAGE_SIZE - len); + zero_user(page, len + page_offset, to_read - len); n = rdata->tailsz = len; len = 0; } else if (page->index > eof_index) { @@ -3622,13 +3641,15 @@ readpages_fill_pages(struct TCP_Server_Info *server, } if (iter) - result = copy_page_from_iter(page, 0, n, iter); + result = copy_page_from_iter( + page, page_offset, n, iter); #ifdef CONFIG_CIFS_SMB_DIRECT else if (rdata->mr) result = n; #endif else - result = cifs_read_page_from_socket(server, page, n); + result = cifs_read_page_from_socket( + server, page, page_offset, n); if (result < 0) break; @@ -3807,6 +3828,7 @@ static int cifs_readpages(struct file *file, struct address_space *mapping, rdata->bytes = bytes; rdata->pid = pid; rdata->pagesz = PAGE_SIZE; + rdata->tailsz = PAGE_SIZE; rdata->read_into_pages = cifs_readpages_read_into_pages; rdata->copy_into_pages = cifs_readpages_copy_into_pages; rdata->credits = credits; -- cgit v1.2.3