From 0702e4f39034f15855def3165fe7213c7c2c0163 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Tue, 18 Feb 2020 23:09:25 -0500 Subject: dlmfs: convert dlmfs_file_read() to copy_to_user() Signed-off-by: Al Viro --- fs/ocfs2/dlmfs/dlmfs.c | 33 ++++++++++++++------------------- 1 file changed, 14 insertions(+), 19 deletions(-) (limited to 'fs/ocfs2') 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, -- cgit v1.2.3