From 71335664c38f03de10d7cf1d82705fe55a130b33 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sat, 9 Jan 2016 19:54:50 -0500 Subject: [PATCH] cifs: don't bother with kmap on read_pages side just do ITER_BVEC recvmsg Signed-off-by: Al Viro --- fs/cifs/cifsproto.h | 7 +++--- fs/cifs/connect.c | 65 ++++++++++++++++++++++++++++------------------------- fs/cifs/file.c | 53 ++++++++++++++----------------------------- 3 files changed, 55 insertions(+), 70 deletions(-) diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h index 7d5f53a..0f9a6bc 100644 --- a/fs/cifs/cifsproto.h +++ b/fs/cifs/cifsproto.h @@ -179,10 +179,9 @@ extern int set_cifs_acl(struct cifs_ntsd *, __u32, struct inode *, extern void dequeue_mid(struct mid_q_entry *mid, bool malformed); extern int cifs_read_from_socket(struct TCP_Server_Info *server, char *buf, - unsigned int to_read); -extern int cifs_readv_from_socket(struct TCP_Server_Info *server, - struct kvec *iov_orig, unsigned int nr_segs, - unsigned int to_read); + unsigned int to_read); +extern int cifs_read_page_from_socket(struct TCP_Server_Info *server, + struct page *page, unsigned int to_read); extern void cifs_setup_cifs_sb(struct smb_vol *pvolume_info, struct cifs_sb_info *cifs_sb); extern int cifs_match_super(struct super_block *, void *); diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index eb42665..e33c5e0 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -501,39 +501,34 @@ server_unresponsive(struct TCP_Server_Info *server) return false; } -int -cifs_readv_from_socket(struct TCP_Server_Info *server, struct kvec *iov_orig, - unsigned int nr_segs, unsigned int to_read) +static int +cifs_readv_from_socket(struct TCP_Server_Info *server, struct msghdr *smb_msg) { int length = 0; int total_read; - struct msghdr smb_msg; - smb_msg.msg_control = NULL; - smb_msg.msg_controllen = 0; - iov_iter_kvec(&smb_msg.msg_iter, READ | ITER_KVEC, - iov_orig, nr_segs, to_read); + smb_msg->msg_control = NULL; + smb_msg->msg_controllen = 0; - for (total_read = 0; msg_data_left(&smb_msg); total_read += length) { + for (total_read = 0; msg_data_left(smb_msg); total_read += length) { try_to_freeze(); - if (server_unresponsive(server)) { - total_read = -ECONNABORTED; - break; - } + if (server_unresponsive(server)) + return -ECONNABORTED; - length = sock_recvmsg(server->ssocket, &smb_msg, 0); + length = sock_recvmsg(server->ssocket, smb_msg, 0); - if (server->tcpStatus == CifsExiting) { - total_read = -ESHUTDOWN; - break; - } else if (server->tcpStatus == CifsNeedReconnect) { + if (server->tcpStatus == CifsExiting) + return -ESHUTDOWN; + + if (server->tcpStatus == CifsNeedReconnect) { cifs_reconnect(server); - total_read = -ECONNABORTED; - break; - } else if (length == -ERESTARTSYS || - length == -EAGAIN || - length == -EINTR) { + return -ECONNABORTED; + } + + if (length == -ERESTARTSYS || + length == -EAGAIN || + length == -EINTR) { /* * Minimum sleep to prevent looping, allowing socket * to clear and app threads to set tcpStatus @@ -542,11 +537,12 @@ cifs_readv_from_socket(struct TCP_Server_Info *server, struct kvec *iov_orig, usleep_range(1000, 2000); length = 0; continue; - } else if (length <= 0) { + } + + if (length <= 0) { cifs_dbg(FYI, "Received no data or error: %d\n", length); cifs_reconnect(server); - total_read = -ECONNABORTED; - break; + return -ECONNABORTED; } } return total_read; @@ -556,12 +552,21 @@ int cifs_read_from_socket(struct TCP_Server_Info *server, char *buf, unsigned int to_read) { - struct kvec iov; + struct msghdr smb_msg; + struct kvec iov = {.iov_base = buf, .iov_len = to_read}; + iov_iter_kvec(&smb_msg.msg_iter, READ | ITER_KVEC, &iov, 1, to_read); - iov.iov_base = buf; - iov.iov_len = to_read; + return cifs_readv_from_socket(server, &smb_msg); +} - return cifs_readv_from_socket(server, &iov, 1, to_read); +int +cifs_read_page_from_socket(struct TCP_Server_Info *server, struct page *page, + unsigned int to_read) +{ + struct msghdr smb_msg; + struct bio_vec bv = {.bv_page = page, .bv_len = to_read}; + iov_iter_bvec(&smb_msg.msg_iter, READ | ITER_BVEC, &bv, 1, to_read); + return cifs_readv_from_socket(server, &smb_msg); } static bool diff --git a/fs/cifs/file.c b/fs/cifs/file.c index ff882ae..0f71867 100644 --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -2855,39 +2855,31 @@ cifs_uncached_read_into_pages(struct TCP_Server_Info *server, int result = 0; unsigned int i; unsigned int nr_pages = rdata->nr_pages; - struct kvec iov; rdata->got_bytes = 0; rdata->tailsz = PAGE_SIZE; for (i = 0; i < nr_pages; i++) { struct page *page = rdata->pages[i]; + size_t n; - if (len >= PAGE_SIZE) { - /* enough data to fill the page */ - iov.iov_base = kmap(page); - iov.iov_len = PAGE_SIZE; - cifs_dbg(FYI, "%u: iov_base=%p iov_len=%zu\n", - i, iov.iov_base, iov.iov_len); - len -= PAGE_SIZE; - } else if (len > 0) { - /* enough for partial page, fill and zero the rest */ - iov.iov_base = kmap(page); - iov.iov_len = len; - cifs_dbg(FYI, "%u: iov_base=%p iov_len=%zu\n", - i, iov.iov_base, iov.iov_len); - memset(iov.iov_base + len, '\0', PAGE_SIZE - len); - rdata->tailsz = len; - len = 0; - } else { + if (len <= 0) { /* no need to hold page hostage */ rdata->pages[i] = NULL; rdata->nr_pages--; put_page(page); continue; } - - result = cifs_readv_from_socket(server, &iov, 1, iov.iov_len); - kunmap(page); + n = len; + if (len >= PAGE_SIZE) { + /* enough data to fill the page */ + n = PAGE_SIZE; + len -= n; + } else { + zero_user(page, len, PAGE_SIZE - len); + rdata->tailsz = len; + len = 0; + } + result = cifs_read_page_from_socket(server, page, n); if (result < 0) break; @@ -3303,7 +3295,6 @@ cifs_readpages_read_into_pages(struct TCP_Server_Info *server, u64 eof; pgoff_t eof_index; unsigned int nr_pages = rdata->nr_pages; - struct kvec iov; /* determine the eof that the server (probably) has */ eof = CIFS_I(rdata->mapping->host)->server_eof; @@ -3314,23 +3305,14 @@ cifs_readpages_read_into_pages(struct TCP_Server_Info *server, rdata->tailsz = PAGE_CACHE_SIZE; for (i = 0; i < nr_pages; i++) { struct page *page = rdata->pages[i]; + size_t n = PAGE_CACHE_SIZE; if (len >= PAGE_CACHE_SIZE) { - /* enough data to fill the page */ - iov.iov_base = kmap(page); - iov.iov_len = PAGE_CACHE_SIZE; - cifs_dbg(FYI, "%u: idx=%lu iov_base=%p iov_len=%zu\n", - i, page->index, iov.iov_base, iov.iov_len); len -= PAGE_CACHE_SIZE; } else if (len > 0) { /* enough for partial page, fill and zero the rest */ - iov.iov_base = kmap(page); - iov.iov_len = len; - cifs_dbg(FYI, "%u: idx=%lu iov_base=%p iov_len=%zu\n", - i, page->index, iov.iov_base, iov.iov_len); - memset(iov.iov_base + len, - '\0', PAGE_CACHE_SIZE - len); - rdata->tailsz = len; + zero_user(page, len, PAGE_CACHE_SIZE - len); + n = rdata->tailsz = len; len = 0; } else if (page->index > eof_index) { /* @@ -3360,8 +3342,7 @@ cifs_readpages_read_into_pages(struct TCP_Server_Info *server, continue; } - result = cifs_readv_from_socket(server, &iov, 1, iov.iov_len); - kunmap(page); + result = cifs_read_page_from_socket(server, page, n); if (result < 0) break; -- 2.7.4