[PATCH] nfsd: fix bad offset use

From: Kent Overstreet
Date: Fri Mar 22 2013 - 14:18:34 EST


vfs_writev() updates the offset argument - but the code then passes the
offset to vfs_fsync_range(). Since offset now points to the offset after
what was just written, this is probably not what was intended

Signed-off-by: Kent Overstreet <koverstreet@xxxxxxxxxx>
Cc: "J. Bruce Fields" <bfields@xxxxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Cc: Zach Brown <zab@xxxxxxxxxx>
---
fs/nfsd/vfs.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 2a7eb53..2b2e239 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -1013,6 +1013,7 @@ nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
int host_err;
int stable = *stablep;
int use_wgather;
+ loff_t pos = offset;

dentry = file->f_path.dentry;
inode = dentry->d_inode;
@@ -1025,7 +1026,7 @@ nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,

/* Write the data. */
oldfs = get_fs(); set_fs(KERNEL_DS);
- host_err = vfs_writev(file, (struct iovec __user *)vec, vlen, &offset);
+ host_err = vfs_writev(file, (struct iovec __user *)vec, vlen, &pos);
set_fs(oldfs);
if (host_err < 0)
goto out_nfserr;
--
1.8.1.3

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