[PATCH 3.2 073/185] nfsd: make sure to balance get/put_write_access

Ben Hutchings
2013-12-29T02:25:42Z

From: Christoph Hellwig <hch@infradead.org>

commit 987da4791052fa298b7cfcde4dea9f6f2bbc786b upstream.

Use a straight goto error label style in nfsd_setattr to make sure
we always do the put_write_access call after we got it earlier.

Note that the we have been failing to do that in the case
nfsd_break_lease() returns an error, a bug introduced into 2.6.38 with
6a76bebefe15d9a08864f824d7f8d5beaf37c997 "nfsd4: break lease on nfsd
setattr".

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
[bwh: Backported to 3.2: notify_change() takes only 2 arguments]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
fs/nfsd/vfs.c | 29 +++++++++++++++--------------
1 file changed, 15 insertions(+), 14 deletions(-)

--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -443,27 +443,28 @@ nfsd_setattr(struct svc_rqst *rqstp, str

iap->ia_valid |= ATTR_CTIME;

- err = nfserr_notsync;
- if (!check_guard || guardtime == inode->i_ctime.tv_sec) {
- host_err = nfsd_break_lease(inode);
- if (host_err)
- goto out_nfserr;
- fh_lock(fhp);
-
- host_err = notify_change(dentry, iap);
- err = nfserrno(host_err);
- fh_unlock(fhp);
+ if (check_guard && guardtime != inode->i_ctime.tv_sec) {
+ err = nfserr_notsync;
+ goto out_put_write_access;
}
+
+ host_err = nfsd_break_lease(inode);
+ if (host_err)
+ goto out_put_write_access_nfserror;
+
+ fh_lock(fhp);
+ host_err = notify_change(dentry, iap);
+ fh_unlock(fhp);
+
+out_put_write_access_nfserror:
+ err = nfserrno(host_err);
+out_put_write_access:
if (size_change)
put_write_access(inode);
if (!err)
commit_metadata(fhp);
out:
return err;
-
-out_nfserr:
- err = nfserrno(host_err);
- goto out;
}

#if defined(CONFIG_NFSD_V2_ACL) || \