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cifs: no need to wank with copying and advancing iovec on recvmsg side either

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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2015-11-13 03:00:17 -05:00
parent 3ab3f2a1fe
commit 09aab880f7
2 changed files with 5 additions and 69 deletions
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2
fs/cifs/cifsglob.h
View file

@ -615,8 +615,6 @@ struct TCP_Server_Info {
bool sec_mskerberos; /* supports legacy MS Kerberos */
bool large_buf; /* is current buffer large? */
struct delayed_work echo; /* echo ping workqueue job */
struct kvec *iov; /* reusable kvec array for receives */
unsigned int nr_iov; /* number of kvecs in array */
char *smallbuf; /* pointer to current "small" buffer */
char *bigbuf; /* pointer to current "big" buffer */
unsigned int total_read; /* total amount of data read in this pass */

72
fs/cifs/connect.c
View file

@ -501,77 +501,20 @@ server_unresponsive(struct TCP_Server_Info *server)
return false;
}
/*
* kvec_array_init - clone a kvec array, and advance into it
* @new: pointer to memory for cloned array
* @iov: pointer to original array
* @nr_segs: number of members in original array
* @bytes: number of bytes to advance into the cloned array
*
* This function will copy the array provided in iov to a section of memory
* and advance the specified number of bytes into the new array. It returns
* the number of segments in the new array. "new" must be at least as big as
* the original iov array.
*/
static unsigned int
kvec_array_init(struct kvec *new, struct kvec *iov, unsigned int nr_segs,
size_t bytes)
{
size_t base = 0;
while (bytes || !iov->iov_len) {
int copy = min(bytes, iov->iov_len);
bytes -= copy;
base += copy;
if (iov->iov_len == base) {
iov++;
nr_segs--;
base = 0;
}
}
memcpy(new, iov, sizeof(*iov) * nr_segs);
new->iov_base += base;
new->iov_len -= base;
return nr_segs;
}
static struct kvec *
get_server_iovec(struct TCP_Server_Info *server, unsigned int nr_segs)
{
struct kvec *new_iov;
if (server->iov && nr_segs <= server->nr_iov)
return server->iov;
/* not big enough -- allocate a new one and release the old */
new_iov = kmalloc(sizeof(*new_iov) * nr_segs, GFP_NOFS);
if (new_iov) {
kfree(server->iov);
server->iov = new_iov;
server->nr_iov = nr_segs;
}
return new_iov;
}
int
cifs_readv_from_socket(struct TCP_Server_Info *server, struct kvec *iov_orig,
unsigned int nr_segs, unsigned int to_read)
{
int length = 0;
int total_read;
unsigned int segs;
struct msghdr smb_msg;
struct kvec *iov;
iov = get_server_iovec(server, nr_segs);
if (!iov)
return -ENOMEM;
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);
for (total_read = 0; to_read; total_read += length, to_read -= length) {
for (total_read = 0; msg_data_left(&smb_msg); total_read += length) {
try_to_freeze();
if (server_unresponsive(server)) {
@ -579,10 +522,7 @@ cifs_readv_from_socket(struct TCP_Server_Info *server, struct kvec *iov_orig,
break;
}
segs = kvec_array_init(iov, iov_orig, nr_segs, total_read);
length = kernel_recvmsg(server->ssocket, &smb_msg,
iov, segs, to_read, 0);
length = sock_recvmsg(server->ssocket, &smb_msg, 0);
if (server->tcpStatus == CifsExiting) {
total_read = -ESHUTDOWN;
@ -603,8 +543,7 @@ cifs_readv_from_socket(struct TCP_Server_Info *server, struct kvec *iov_orig,
length = 0;
continue;
} else if (length <= 0) {
cifs_dbg(FYI, "Received no data or error: expecting %d\n"
"got %d", to_read, length);
cifs_dbg(FYI, "Received no data or error: %d\n", length);
cifs_reconnect(server);
total_read = -ECONNABORTED;
break;
@ -783,7 +722,6 @@ static void clean_demultiplex_info(struct TCP_Server_Info *server)
}
kfree(server->hostname);
kfree(server->iov);
kfree(server);
length = atomic_dec_return(&tcpSesAllocCount);