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Subject[PATCH 2/2] dlmfs: convert dlmfs_file_read() to copy_to_user()
Date
From: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
fs/ocfs2/dlmfs/dlmfs.c | 33 ++++++++++++++-------------------
1 file changed, 14 insertions(+), 19 deletions(-)

diff --git a/fs/ocfs2/dlmfs/dlmfs.c b/fs/ocfs2/dlmfs/dlmfs.c
index 8e4f1ace467c..92f0a3bc3ac5 100644
--- a/fs/ocfs2/dlmfs/dlmfs.c
+++ b/fs/ocfs2/dlmfs/dlmfs.c
@@ -227,7 +227,7 @@ static ssize_t dlmfs_file_read(struct file *filp,
loff_t *ppos)
{
int bytes_left;
- ssize_t readlen, got;
+ ssize_t got;
char *lvb_buf;
struct inode *inode = file_inode(filp);

@@ -237,36 +237,31 @@ static ssize_t dlmfs_file_read(struct file *filp,
if (*ppos >= i_size_read(inode))
return 0;

+ /* don't read past the lvb */
+ if (count > i_size_read(inode) - *ppos)
+ count = i_size_read(inode) - *ppos;
+
if (!count)
return 0;

- if (!access_ok(buf, count))
- return -EFAULT;
-
- /* don't read past the lvb */
- if ((count + *ppos) > i_size_read(inode))
- readlen = i_size_read(inode) - *ppos;
- else
- readlen = count;
-
- lvb_buf = kmalloc(readlen, GFP_NOFS);
+ lvb_buf = kmalloc(count, GFP_NOFS);
if (!lvb_buf)
return -ENOMEM;

- got = user_dlm_read_lvb(inode, lvb_buf, readlen);
+ got = user_dlm_read_lvb(inode, lvb_buf, count);
if (got) {
- BUG_ON(got != readlen);
- bytes_left = __copy_to_user(buf, lvb_buf, readlen);
- readlen -= bytes_left;
+ BUG_ON(got != count);
+ bytes_left = copy_to_user(buf, lvb_buf, count);
+ count -= bytes_left;
} else
- readlen = 0;
+ count = 0;

kfree(lvb_buf);

- *ppos = *ppos + readlen;
+ *ppos = *ppos + count;

- mlog(0, "read %zd bytes\n", readlen);
- return readlen;
+ mlog(0, "read %zu bytes\n", count);
+ return count;
}

static ssize_t dlmfs_file_write(struct file *filp,
--
2.11.0
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