From 0ada36b244e8316bb47b46b84b33c5a507bed7a4 Mon Sep 17 00:00:00 2001 From: Pavel Shilovsky Date: Wed, 25 Jun 2014 10:42:28 +0400 Subject: [PATCH] CIFS: Separate page reading from user read Reviewed-by: Shirish Pargaonkar Signed-off-by: Pavel Shilovsky Signed-off-by: Steve French --- fs/cifs/file.c | 69 ++++++++++++++++++++++++++++++-------------------- 1 file changed, 41 insertions(+), 28 deletions(-) diff --git a/fs/cifs/file.c b/fs/cifs/file.c index d6279185e2f0..7df4e4658d74 100644 --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -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; -- 2.20.1