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authorJ. Bruce Fields <bfields@redhat.com>2017-02-09 14:20:42 -0500
committerJ. Bruce Fields <bfields@redhat.com>2017-02-09 20:49:20 -0500
commit0839ffb83e44e5ff1843e932592525fc2bff23ff (patch)
treeb5ac49bc5f31db6937c2333612148977efd395af /fs
parentd5adbfcd5f7bcc6fa58a41c5c5ada0e5c826ce2c (diff)
downloadlinux-0839ffb83e44e5ff1843e932592525fc2bff23ff.tar.bz2
nfsd: Revert "nfsd: special case truncates some more"
This patch incorrectly attempted nested mnt_want_write, and incorrectly disabled nfsd's owner override for truncate. We'll fix those problems and make another attempt soon, for the moment I think the safest is to revert. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Diffstat (limited to 'fs')
-rw-r--r--fs/nfsd/vfs.c97
1 files changed, 60 insertions, 37 deletions
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index ca13236dbb1f..26c6fdb4bf67 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -332,6 +332,37 @@ nfsd_sanitize_attrs(struct inode *inode, struct iattr *iap)
}
}
+static __be32
+nfsd_get_write_access(struct svc_rqst *rqstp, struct svc_fh *fhp,
+ struct iattr *iap)
+{
+ struct inode *inode = d_inode(fhp->fh_dentry);
+ int host_err;
+
+ if (iap->ia_size < inode->i_size) {
+ __be32 err;
+
+ err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry,
+ NFSD_MAY_TRUNC | NFSD_MAY_OWNER_OVERRIDE);
+ if (err)
+ return err;
+ }
+
+ host_err = get_write_access(inode);
+ if (host_err)
+ goto out_nfserrno;
+
+ host_err = locks_verify_truncate(inode, NULL, iap->ia_size);
+ if (host_err)
+ goto out_put_write_access;
+ return 0;
+
+out_put_write_access:
+ put_write_access(inode);
+out_nfserrno:
+ return nfserrno(host_err);
+}
+
/*
* Set various file attributes. After this call fhp needs an fh_put.
*/
@@ -346,6 +377,7 @@ nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap,
__be32 err;
int host_err;
bool get_write_count;
+ int size_change = 0;
if (iap->ia_valid & (ATTR_ATIME | ATTR_MTIME | ATTR_SIZE))
accmode |= NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE;
@@ -358,11 +390,11 @@ nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap,
/* Get inode */
err = fh_verify(rqstp, fhp, ftype, accmode);
if (err)
- return err;
+ goto out;
if (get_write_count) {
host_err = fh_want_write(fhp);
if (host_err)
- goto out_host_err;
+ return nfserrno(host_err);
}
dentry = fhp->fh_dentry;
@@ -373,59 +405,50 @@ nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap,
iap->ia_valid &= ~ATTR_MODE;
if (!iap->ia_valid)
- return 0;
+ goto out;
nfsd_sanitize_attrs(inode, iap);
- if (check_guard && guardtime != inode->i_ctime.tv_sec)
- return nfserr_notsync;
-
/*
* The size case is special, it changes the file in addition to the
- * attributes, and file systems don't expect it to be mixed with
- * "random" attribute changes. We thus split out the size change
- * into a separate call for vfs_truncate, and do the rest as a
- * a separate setattr call.
+ * attributes.
*/
if (iap->ia_valid & ATTR_SIZE) {
- struct path path = {
- .mnt = fhp->fh_export->ex_path.mnt,
- .dentry = dentry,
- };
- bool implicit_mtime = false;
+ err = nfsd_get_write_access(rqstp, fhp, iap);
+ if (err)
+ goto out;
+ size_change = 1;
/*
- * vfs_truncate implicity updates the mtime IFF the file size
- * actually changes. Avoid the additional seattr call below if
- * the only other attribute that the client sends is the mtime.
+ * RFC5661, Section 18.30.4:
+ * Changing the size of a file with SETATTR indirectly
+ * changes the time_modify and change attributes.
+ *
+ * (and similar for the older RFCs)
*/
- if (iap->ia_size != i_size_read(inode) &&
- ((iap->ia_valid & ~(ATTR_SIZE | ATTR_MTIME)) == 0))
- implicit_mtime = true;
-
- host_err = vfs_truncate(&path, iap->ia_size);
- if (host_err)
- goto out_host_err;
-
- iap->ia_valid &= ~ATTR_SIZE;
- if (implicit_mtime)
- iap->ia_valid &= ~ATTR_MTIME;
- if (!iap->ia_valid)
- goto done;
+ if (iap->ia_size != i_size_read(inode))
+ iap->ia_valid |= ATTR_MTIME;
}
iap->ia_valid |= ATTR_CTIME;
+ if (check_guard && guardtime != inode->i_ctime.tv_sec) {
+ err = nfserr_notsync;
+ goto out_put_write_access;
+ }
+
fh_lock(fhp);
host_err = notify_change(dentry, iap, NULL);
fh_unlock(fhp);
- if (host_err)
- goto out_host_err;
+ err = nfserrno(host_err);
-done:
- host_err = commit_metadata(fhp);
-out_host_err:
- return nfserrno(host_err);
+out_put_write_access:
+ if (size_change)
+ put_write_access(inode);
+ if (!err)
+ err = nfserrno(commit_metadata(fhp));
+out:
+ return err;
}
#if defined(CONFIG_NFSD_V4)