CIFS: Separate page reading from user read

Reviewed-by: Shirish Pargaonkar <spargaonkar@suse.com>
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
This commit is contained in:
Pavel Shilovsky 2014-06-25 10:42:28 +04:00 committed by Steve French
parent 69cebd7560
commit 0ada36b244

View File

@ -2932,43 +2932,23 @@ cifs_uncached_read_into_pages(struct TCP_Server_Info *server,
return total_read > 0 && result != -EAGAIN ? total_read : result;
}
ssize_t cifs_user_readv(struct kiocb *iocb, struct iov_iter *to)
static int
cifs_send_async_read(loff_t offset, size_t len, struct cifsFileInfo *open_file,
struct cifs_sb_info *cifs_sb, struct list_head *rdata_list)
{
struct file *file = iocb->ki_filp;
ssize_t rc;
size_t len, cur_len;
ssize_t total_read = 0;
loff_t offset = iocb->ki_pos;
struct cifs_readdata *rdata;
unsigned int npages;
struct cifs_sb_info *cifs_sb;
struct cifs_tcon *tcon;
struct cifsFileInfo *open_file;
struct cifs_readdata *rdata, *tmp;
struct list_head rdata_list;
size_t cur_len;
int rc;
pid_t pid;
len = iov_iter_count(to);
if (!len)
return 0;
INIT_LIST_HEAD(&rdata_list);
cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
open_file = file->private_data;
tcon = tlink_tcon(open_file->tlink);
if (!tcon->ses->server->ops->async_readv)
return -ENOSYS;
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
pid = open_file->pid;
else
pid = current->tgid;
if ((file->f_flags & O_ACCMODE) == O_WRONLY)
cifs_dbg(FYI, "attempting read on write only file instance\n");
do {
cur_len = min_t(const size_t, len - total_read, cifs_sb->rsize);
cur_len = min_t(const size_t, len, cifs_sb->rsize);
npages = DIV_ROUND_UP(cur_len, PAGE_SIZE);
/* allocate a readdata struct */
@ -2999,11 +2979,44 @@ error:
break;
}
list_add_tail(&rdata->list, &rdata_list);
list_add_tail(&rdata->list, rdata_list);
offset += cur_len;
len -= cur_len;
} while (len > 0);
return rc;
}
ssize_t cifs_user_readv(struct kiocb *iocb, struct iov_iter *to)
{
struct file *file = iocb->ki_filp;
ssize_t rc;
size_t len;
ssize_t total_read = 0;
loff_t offset = iocb->ki_pos;
struct cifs_sb_info *cifs_sb;
struct cifs_tcon *tcon;
struct cifsFileInfo *open_file;
struct cifs_readdata *rdata, *tmp;
struct list_head rdata_list;
len = iov_iter_count(to);
if (!len)
return 0;
INIT_LIST_HEAD(&rdata_list);
cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
open_file = file->private_data;
tcon = tlink_tcon(open_file->tlink);
if (!tcon->ses->server->ops->async_readv)
return -ENOSYS;
if ((file->f_flags & O_ACCMODE) == O_WRONLY)
cifs_dbg(FYI, "attempting read on write only file instance\n");
rc = cifs_send_async_read(offset, len, open_file, cifs_sb, &rdata_list);
/* if at least one read request send succeeded, then reset rc */
if (!list_empty(&rdata_list))
rc = 0;