From 9f67f189939eccaa54f3d2c9cf10788abaf2d584 Mon Sep 17 00:00:00 2001 From: "J. Bruce Fields" Date: Mon, 24 Feb 2014 14:59:47 -0500 Subject: [PATCH] nfsd: notify_change needs elevated write count Looks like this bug has been here since these write counts were introduced, not sure why it was just noticed now. Thanks also to Jan Kara for pointing out the problem. Cc: stable@vger.kernel.org Reported-by: Matthew Rahtz Signed-off-by: J. Bruce Fields --- fs/nfsd/vfs.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index 6d7be3f80356..eea5ad188984 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -404,6 +404,7 @@ nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap, umode_t ftype = 0; __be32 err; int host_err; + bool get_write_count; int size_change = 0; if (iap->ia_valid & (ATTR_ATIME | ATTR_MTIME | ATTR_SIZE)) @@ -411,10 +412,18 @@ nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap, if (iap->ia_valid & ATTR_SIZE) ftype = S_IFREG; + /* Callers that do fh_verify should do the fh_want_write: */ + get_write_count = !fhp->fh_dentry; + /* Get inode */ err = fh_verify(rqstp, fhp, ftype, accmode); if (err) goto out; + if (get_write_count) { + host_err = fh_want_write(fhp); + if (host_err) + return nfserrno(host_err); + } dentry = fhp->fh_dentry; inode = dentry->d_inode; -- 2.34.1