Commit 0ada36b2 authored by Pavel Shilovsky's avatar Pavel Shilovsky Committed by Steve French
Browse files

CIFS: Separate page reading from user read 



Reviewed-by: default avatarShirish Pargaonkar <spargaonkar@suse.com>
Signed-off-by: default avatarPavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: default avatarSteve French <smfrench@gmail.com>
parent 69cebd75

fs/cifs/file.c

+41 −28
Original line number Diff line number Diff line
@@ -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 @@ ssize_t cifs_user_readv(struct kiocb *iocb, struct iov_iter *to) 
			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;