Commit a70307ee authored by Pavel Shilovsky's avatar Pavel Shilovsky Committed by Steve French

CIFS: Implement cifs_strict_readv (try #4)

Read from the cache if we have at least Level II oplock - otherwise
read from the server. Add cifs_user_readv to let the client read into
iovec buffers.
Reviewed-by: default avatarJeff Layton <jlayton@redhat.com>
Signed-off-by: default avatarPavel Shilovsky <piastryyy@gmail.com>
Signed-off-by: default avatarSteve French <sfrench@us.ibm.com>
parent 7a6a19b1
......@@ -736,7 +736,7 @@ const struct file_operations cifs_file_ops = {
const struct file_operations cifs_file_strict_ops = {
.read = do_sync_read,
.write = do_sync_write,
.aio_read = generic_file_aio_read,
.aio_read = cifs_strict_readv,
.aio_write = cifs_file_aio_write,
.open = cifs_open,
.release = cifs_close,
......@@ -792,7 +792,7 @@ const struct file_operations cifs_file_nobrl_ops = {
const struct file_operations cifs_file_strict_nobrl_ops = {
.read = do_sync_read,
.write = do_sync_write,
.aio_read = generic_file_aio_read,
.aio_read = cifs_strict_readv,
.aio_write = cifs_file_aio_write,
.open = cifs_open,
.release = cifs_close,
......
......@@ -81,7 +81,9 @@ extern int cifs_open(struct inode *inode, struct file *file);
extern int cifs_close(struct inode *inode, struct file *file);
extern int cifs_closedir(struct inode *inode, struct file *file);
extern ssize_t cifs_user_read(struct file *file, char __user *read_data,
size_t read_size, loff_t *poffset);
size_t read_size, loff_t *poffset);
extern ssize_t cifs_strict_readv(struct kiocb *iocb, const struct iovec *iov,
unsigned long nr_segs, loff_t pos);
extern ssize_t cifs_user_write(struct file *file, const char __user *write_data,
size_t write_size, loff_t *poffset);
extern int cifs_lock(struct file *, int, struct file_lock *);
......
......@@ -1619,42 +1619,42 @@ int cifs_flush(struct file *file, fl_owner_t id)
return rc;
}
ssize_t cifs_user_read(struct file *file, char __user *read_data,
size_t read_size, loff_t *poffset)
static ssize_t
cifs_iovec_read(struct file *file, const struct iovec *iov,
unsigned long nr_segs, loff_t *poffset)
{
int rc = -EACCES;
unsigned int bytes_read = 0;
unsigned int total_read = 0;
unsigned int current_read_size;
int rc;
int xid;
unsigned int total_read, bytes_read = 0;
size_t len, cur_len;
int iov_offset = 0;
struct cifs_sb_info *cifs_sb;
struct cifsTconInfo *pTcon;
int xid;
struct cifsFileInfo *open_file;
char *smb_read_data;
char __user *current_offset;
struct smb_com_read_rsp *pSMBr;
char *read_data;
if (!nr_segs)
return 0;
len = iov_length(iov, nr_segs);
if (!len)
return 0;
xid = GetXid();
cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
if (file->private_data == NULL) {
rc = -EBADF;
FreeXid(xid);
return rc;
}
open_file = file->private_data;
pTcon = tlink_tcon(open_file->tlink);
if ((file->f_flags & O_ACCMODE) == O_WRONLY)
cFYI(1, "attempting read on write only file instance");
for (total_read = 0, current_offset = read_data;
read_size > total_read;
total_read += bytes_read, current_offset += bytes_read) {
current_read_size = min_t(const int, read_size - total_read,
cifs_sb->rsize);
for (total_read = 0; total_read < len; total_read += bytes_read) {
cur_len = min_t(const size_t, len - total_read, cifs_sb->rsize);
rc = -EAGAIN;
smb_read_data = NULL;
read_data = NULL;
while (rc == -EAGAIN) {
int buf_type = CIFS_NO_BUFFER;
if (open_file->invalidHandle) {
......@@ -1662,27 +1662,25 @@ ssize_t cifs_user_read(struct file *file, char __user *read_data,
if (rc != 0)
break;
}
rc = CIFSSMBRead(xid, pTcon,
open_file->netfid,
current_read_size, *poffset,
&bytes_read, &smb_read_data,
&buf_type);
pSMBr = (struct smb_com_read_rsp *)smb_read_data;
if (smb_read_data) {
if (copy_to_user(current_offset,
smb_read_data +
4 /* RFC1001 length field */ +
le16_to_cpu(pSMBr->DataOffset),
bytes_read))
rc = CIFSSMBRead(xid, pTcon, open_file->netfid,
cur_len, *poffset, &bytes_read,
&read_data, &buf_type);
pSMBr = (struct smb_com_read_rsp *)read_data;
if (read_data) {
char *data_offset = read_data + 4 +
le16_to_cpu(pSMBr->DataOffset);
if (memcpy_toiovecend(iov, data_offset,
iov_offset, bytes_read))
rc = -EFAULT;
if (buf_type == CIFS_SMALL_BUFFER)
cifs_small_buf_release(smb_read_data);
cifs_small_buf_release(read_data);
else if (buf_type == CIFS_LARGE_BUFFER)
cifs_buf_release(smb_read_data);
smb_read_data = NULL;
cifs_buf_release(read_data);
read_data = NULL;
iov_offset += bytes_read;
}
}
if (rc || (bytes_read == 0)) {
if (total_read) {
break;
......@@ -1695,13 +1693,57 @@ ssize_t cifs_user_read(struct file *file, char __user *read_data,
*poffset += bytes_read;
}
}
FreeXid(xid);
return total_read;
}
ssize_t cifs_user_read(struct file *file, char __user *read_data,
size_t read_size, loff_t *poffset)
{
struct iovec iov;
iov.iov_base = read_data;
iov.iov_len = read_size;
return cifs_iovec_read(file, &iov, 1, poffset);
}
static ssize_t cifs_user_readv(struct kiocb *iocb, const struct iovec *iov,
unsigned long nr_segs, loff_t pos)
{
ssize_t read;
read = cifs_iovec_read(iocb->ki_filp, iov, nr_segs, &pos);
if (read > 0)
iocb->ki_pos = pos;
return read;
}
ssize_t cifs_strict_readv(struct kiocb *iocb, const struct iovec *iov,
unsigned long nr_segs, loff_t pos)
{
struct inode *inode;
inode = iocb->ki_filp->f_path.dentry->d_inode;
if (CIFS_I(inode)->clientCanCacheRead)
return generic_file_aio_read(iocb, iov, nr_segs, pos);
/*
* In strict cache mode we need to read from the server all the time
* if we don't have level II oplock because the server can delay mtime
* change - so we can't make a decision about inode invalidating.
* And we can also fail with pagereading if there are mandatory locks
* on pages affected by this read but not on the region from pos to
* pos+len-1.
*/
return cifs_user_readv(iocb, iov, nr_segs, pos);
}
static ssize_t cifs_read(struct file *file, char *read_data, size_t read_size,
loff_t *poffset)
loff_t *poffset)
{
int rc = -EACCES;
unsigned int bytes_read = 0;
......
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