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Date: Sat, 9 Apr 2016 21:53:04 +0100
From: Al Viro <viro@...IV.linux.org.uk>
To: linux-cifs@...r.kernel.org
Cc: linux-kernel@...r.kernel.org
Subject: [PATCH 6/6] cifs: don't bother with kmap on read_pages side
just do ITER_BVEC recvmsg
Signed-off-by: Al Viro <viro@...iv.linux.org.uk>
---
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;
--
2.8.0.rc3
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