9p: switch p9_client_read() to passing struct iov_iter *

... and make it loop

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2015-04-01 23:42:28 -04:00
parent 9565a54452
commit e1200fe68f
7 changed files with 110 additions and 185 deletions

View file

@ -68,8 +68,6 @@ int v9fs_file_open(struct inode *inode, struct file *file);
void v9fs_inode2stat(struct inode *inode, struct p9_wstat *stat);
int v9fs_uflags2omode(int uflags, int extended);
ssize_t v9fs_file_readn(struct file *, char *, char __user *, u32, u64);
ssize_t v9fs_fid_readn(struct p9_fid *, char *, char __user *, u32, u64);
void v9fs_blank_wstat(struct p9_wstat *wstat);
int v9fs_vfs_setattr_dotl(struct dentry *, struct iattr *);
int v9fs_file_fsync_dotl(struct file *filp, loff_t start, loff_t end,

View file

@ -51,12 +51,11 @@
*/
static int v9fs_fid_readpage(struct p9_fid *fid, struct page *page)
{
int retval;
loff_t offset;
char *buffer;
struct inode *inode;
struct inode *inode = page->mapping->host;
struct bio_vec bvec = {.bv_page = page, .bv_len = PAGE_SIZE};
struct iov_iter to;
int retval, err;
inode = page->mapping->host;
p9_debug(P9_DEBUG_VFS, "\n");
BUG_ON(!PageLocked(page));
@ -65,16 +64,16 @@ static int v9fs_fid_readpage(struct p9_fid *fid, struct page *page)
if (retval == 0)
return retval;
buffer = kmap(page);
offset = page_offset(page);
iov_iter_bvec(&to, ITER_BVEC | READ, &bvec, 1, PAGE_SIZE);
retval = v9fs_fid_readn(fid, buffer, NULL, PAGE_CACHE_SIZE, offset);
if (retval < 0) {
retval = p9_client_read(fid, page_offset(page), &to, &err);
if (err) {
v9fs_uncache_page(inode, page);
retval = err;
goto done;
}
memset(buffer + retval, 0, PAGE_CACHE_SIZE - retval);
zero_user(page, retval, PAGE_SIZE - retval);
flush_dcache_page(page);
SetPageUptodate(page);
@ -82,7 +81,6 @@ static int v9fs_fid_readpage(struct p9_fid *fid, struct page *page)
retval = 0;
done:
kunmap(page);
unlock_page(page);
return retval;
}

View file

@ -33,6 +33,7 @@
#include <linux/inet.h>
#include <linux/idr.h>
#include <linux/slab.h>
#include <linux/uio.h>
#include <net/9p/9p.h>
#include <net/9p/client.h>
@ -115,6 +116,7 @@ static int v9fs_dir_readdir(struct file *file, struct dir_context *ctx)
int buflen;
int reclen = 0;
struct p9_rdir *rdir;
struct kvec kvec;
p9_debug(P9_DEBUG_VFS, "name %pD\n", file);
fid = file->private_data;
@ -124,16 +126,21 @@ static int v9fs_dir_readdir(struct file *file, struct dir_context *ctx)
rdir = v9fs_alloc_rdir_buf(file, buflen);
if (!rdir)
return -ENOMEM;
kvec.iov_base = rdir->buf;
kvec.iov_len = buflen;
while (1) {
if (rdir->tail == rdir->head) {
err = v9fs_file_readn(file, rdir->buf, NULL,
buflen, ctx->pos);
if (err <= 0)
struct iov_iter to;
int n;
iov_iter_kvec(&to, READ | ITER_KVEC, &kvec, 1, buflen);
n = p9_client_read(file->private_data, ctx->pos, &to,
&err);
if (err)
return err;
rdir->head = 0;
rdir->tail = err;
rdir->tail = n;
}
while (rdir->head < rdir->tail) {
p9stat_init(&st);

View file

@ -364,63 +364,6 @@ out_err:
return ret;
}
/**
* v9fs_fid_readn - read from a fid
* @fid: fid to read
* @data: data buffer to read data into
* @udata: user data buffer to read data into
* @count: size of buffer
* @offset: offset at which to read data
*
*/
ssize_t
v9fs_fid_readn(struct p9_fid *fid, char *data, char __user *udata, u32 count,
u64 offset)
{
int n, total, size;
p9_debug(P9_DEBUG_VFS, "fid %d offset %llu count %d\n",
fid->fid, (long long unsigned)offset, count);
n = 0;
total = 0;
size = fid->iounit ? fid->iounit : fid->clnt->msize - P9_IOHDRSZ;
do {
n = p9_client_read(fid, data, udata, offset, count);
if (n <= 0)
break;
if (data)
data += n;
if (udata)
udata += n;
offset += n;
count -= n;
total += n;
} while (count > 0 && n == size);
if (n < 0)
total = n;
return total;
}
/**
* v9fs_file_readn - read from a file
* @filp: file pointer to read
* @data: data buffer to read data into
* @udata: user data buffer to read data into
* @count: size of buffer
* @offset: offset at which to read data
*
*/
ssize_t
v9fs_file_readn(struct file *filp, char *data, char __user *udata, u32 count,
u64 offset)
{
return v9fs_fid_readn(filp->private_data, data, udata, count, offset);
}
/**
* v9fs_file_read - read from a file
* @filp: file pointer to read
@ -434,22 +377,20 @@ static ssize_t
v9fs_file_read(struct file *filp, char __user *udata, size_t count,
loff_t * offset)
{
int ret;
struct p9_fid *fid;
size_t size;
struct p9_fid *fid = filp->private_data;
struct iovec iov = {.iov_base = udata, .iov_len = count};
struct iov_iter to;
int ret, err;
iov_iter_init(&to, READ, &iov, 1, count);
p9_debug(P9_DEBUG_VFS, "count %zu offset %lld\n", count, *offset);
fid = filp->private_data;
size = fid->iounit ? fid->iounit : fid->clnt->msize - P9_IOHDRSZ;
if (count > size)
ret = v9fs_file_readn(filp, NULL, udata, count, *offset);
else
ret = p9_client_read(fid, NULL, udata, *offset, count);
if (ret > 0)
*offset += ret;
ret = p9_client_read(fid, *offset, &to, &err);
if (!ret)
return err;
*offset += ret;
return ret;
}

View file

@ -26,50 +26,34 @@ ssize_t v9fs_fid_xattr_get(struct p9_fid *fid, const char *name,
void *buffer, size_t buffer_size)
{
ssize_t retval;
int msize, read_count;
u64 offset = 0, attr_size;
u64 attr_size;
struct p9_fid *attr_fid;
struct kvec kvec = {.iov_base = buffer, .iov_len = buffer_size};
struct iov_iter to;
int err;
iov_iter_kvec(&to, READ | ITER_KVEC, &kvec, 1, buffer_size);
attr_fid = p9_client_xattrwalk(fid, name, &attr_size);
if (IS_ERR(attr_fid)) {
retval = PTR_ERR(attr_fid);
p9_debug(P9_DEBUG_VFS, "p9_client_attrwalk failed %zd\n",
retval);
attr_fid = NULL;
goto error;
}
if (!buffer_size) {
/* request to get the attr_size */
retval = attr_size;
goto error;
return retval;
}
if (attr_size > buffer_size) {
retval = -ERANGE;
goto error;
}
msize = attr_fid->clnt->msize;
while (attr_size) {
if (attr_size > (msize - P9_IOHDRSZ))
read_count = msize - P9_IOHDRSZ;
if (!buffer_size) /* request to get the attr_size */
retval = attr_size;
else
read_count = attr_size;
read_count = p9_client_read(attr_fid, ((char *)buffer)+offset,
NULL, offset, read_count);
if (read_count < 0) {
/* error in xattr read */
retval = read_count;
goto error;
}
offset += read_count;
attr_size -= read_count;
retval = -ERANGE;
} else {
iov_iter_truncate(&to, attr_size);
retval = p9_client_read(attr_fid, 0, &to, &err);
if (err)
retval = err;
}
/* Total read xattr bytes */
retval = offset;
error:
if (attr_fid)
p9_client_clunk(attr_fid);
p9_client_clunk(attr_fid);
return retval;
}

View file

@ -238,8 +238,7 @@ int p9_client_clunk(struct p9_fid *fid);
int p9_client_fsync(struct p9_fid *fid, int datasync);
int p9_client_remove(struct p9_fid *fid);
int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags);
int p9_client_read(struct p9_fid *fid, char *data, char __user *udata,
u64 offset, u32 count);
int p9_client_read(struct p9_fid *fid, u64 offset, struct iov_iter *to, int *err);
int p9_client_write(struct p9_fid *fid, u64 offset, struct iov_iter *from, int *err);
int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset);
int p9dirent_read(struct p9_client *clnt, char *buf, int len,

View file

@ -1534,79 +1534,77 @@ error:
EXPORT_SYMBOL(p9_client_unlinkat);
int
p9_client_read(struct p9_fid *fid, char *data, char __user *udata, u64 offset,
u32 count)
p9_client_read(struct p9_fid *fid, u64 offset, struct iov_iter *to, int *err)
{
char *dataptr;
struct p9_client *clnt = fid->clnt;
struct p9_req_t *req;
struct p9_client *clnt;
int err, rsize, non_zc = 0;
struct iov_iter to;
union {
struct kvec kv;
struct iovec iov;
} v;
if (data) {
v.kv.iov_base = data;
v.kv.iov_len = count;
iov_iter_kvec(&to, ITER_KVEC | READ, &v.kv, 1, count);
} else {
v.iov.iov_base = udata;
v.iov.iov_len = count;
iov_iter_init(&to, READ, &v.iov, 1, count);
}
int total = 0;
p9_debug(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n",
fid->fid, (unsigned long long) offset, count);
err = 0;
clnt = fid->clnt;
fid->fid, (unsigned long long) offset, (int)iov_iter_count(to));
rsize = fid->iounit;
if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
rsize = clnt->msize - P9_IOHDRSZ;
while (iov_iter_count(to)) {
int count = iov_iter_count(to);
int rsize, non_zc = 0;
char *dataptr;
rsize = fid->iounit;
if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
rsize = clnt->msize - P9_IOHDRSZ;
if (count < rsize)
rsize = count;
if (count < rsize)
rsize = count;
/* Don't bother zerocopy for small IO (< 1024) */
if (clnt->trans_mod->zc_request && rsize > 1024) {
/*
* response header len is 11
* PDU Header(7) + IO Size (4)
*/
req = p9_client_zc_rpc(clnt, P9_TREAD, &to, NULL, rsize, 0,
11, "dqd", fid->fid,
offset, rsize);
} else {
non_zc = 1;
req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset,
rsize);
/* Don't bother zerocopy for small IO (< 1024) */
if (clnt->trans_mod->zc_request && rsize > 1024) {
/*
* response header len is 11
* PDU Header(7) + IO Size (4)
*/
req = p9_client_zc_rpc(clnt, P9_TREAD, to, NULL, rsize,
0, 11, "dqd", fid->fid,
offset, rsize);
} else {
non_zc = 1;
req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset,
rsize);
}
if (IS_ERR(req)) {
*err = PTR_ERR(req);
break;
}
*err = p9pdu_readf(req->rc, clnt->proto_version,
"D", &count, &dataptr);
if (*err) {
trace_9p_protocol_dump(clnt, req->rc);
p9_free_req(clnt, req);
break;
}
p9_debug(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
if (!count) {
p9_free_req(clnt, req);
break;
}
if (non_zc) {
int n = copy_to_iter(dataptr, count, to);
total += n;
offset += n;
if (n != count) {
*err = -EFAULT;
p9_free_req(clnt, req);
break;
}
} else {
iov_iter_advance(to, count);
total += count;
offset += count;
}
p9_free_req(clnt, req);
}
if (IS_ERR(req)) {
err = PTR_ERR(req);
goto error;
}
err = p9pdu_readf(req->rc, clnt->proto_version, "D", &count, &dataptr);
if (err) {
trace_9p_protocol_dump(clnt, req->rc);
goto free_and_error;
}
p9_debug(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
if (non_zc && copy_to_iter(dataptr, count, &to) != count) {
err = -EFAULT;
goto free_and_error;
}
p9_free_req(clnt, req);
return count;
free_and_error:
p9_free_req(clnt, req);
error:
return err;
return total;
}
EXPORT_SYMBOL(p9_client_read);