[PATCH 19/22] xfs: scrub symbolic links

Darrick J. Wong
2017-07-21T04:40:35Z

From: Darrick J. Wong <darrick.wong@oracle.com>

Create the infrastructure to scrub symbolic link data.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
fs/xfs/Makefile | 1 +
fs/xfs/libxfs/xfs_fs.h | 3 +-
fs/xfs/scrub/common.c | 4 ++
fs/xfs/scrub/common.h | 2 +
fs/xfs/scrub/symlink.c | 94 ++++++++++++++++++++++++++++++++++++++++++++++++
fs/xfs/xfs_trace.h | 3 +-
6 files changed, 105 insertions(+), 2 deletions(-)
create mode 100644 fs/xfs/scrub/symlink.c

diff --git a/fs/xfs/Makefile b/fs/xfs/Makefile
index da64bef..3d862b9 100644
--- a/fs/xfs/Makefile
+++ b/fs/xfs/Makefile
@@ -153,5 +153,6 @@ xfs-y += $(addprefix scrub/, \
metabufs.o \
refcount.o \
rmap.o \
+ symlink.o \
)
endif
diff --git a/fs/xfs/libxfs/xfs_fs.h b/fs/xfs/libxfs/xfs_fs.h
index 2f553ed..95d9ce9 100644
--- a/fs/xfs/libxfs/xfs_fs.h
+++ b/fs/xfs/libxfs/xfs_fs.h
@@ -499,7 +499,8 @@ struct xfs_scrub_metadata {
#define XFS_SCRUB_TYPE_BMBTC 15 /* CoW fork block mapping */
#define XFS_SCRUB_TYPE_DIR 16 /* directory */
#define XFS_SCRUB_TYPE_XATTR 17 /* extended attribute */
-#define XFS_SCRUB_TYPE_MAX 17
+#define XFS_SCRUB_TYPE_SYMLINK 18 /* symbolic link */
+#define XFS_SCRUB_TYPE_MAX 18

/* i: repair this metadata */
#define XFS_SCRUB_FLAG_REPAIR (1 << 0)
diff --git a/fs/xfs/scrub/common.c b/fs/xfs/scrub/common.c
index a47c654..4003c2f 100644
--- a/fs/xfs/scrub/common.c
+++ b/fs/xfs/scrub/common.c
@@ -852,6 +852,10 @@ static const struct xfs_scrub_meta_fns meta_scrub_fns[] = {
.setup = xfs_scrub_setup_xattr,
.scrub = xfs_scrub_xattr,
},
+ { /* symbolic link */
+ .setup = xfs_scrub_setup_symlink,
+ .scrub = xfs_scrub_symlink,
+ },
};

/* Dispatch metadata scrubbing. */
diff --git a/fs/xfs/scrub/common.h b/fs/xfs/scrub/common.h
index 1cfe0cc..6d02a64 100644
--- a/fs/xfs/scrub/common.h
+++ b/fs/xfs/scrub/common.h
@@ -223,6 +223,7 @@ SETUP_FN(xfs_scrub_setup_inode_bmap_data);
SETUP_FN(xfs_scrub_setup_inode_bmap);
SETUP_FN(xfs_scrub_setup_directory);
SETUP_FN(xfs_scrub_setup_xattr);
+SETUP_FN(xfs_scrub_setup_symlink);
#undef SETUP_FN

/* Metadata scrubbers */
@@ -246,6 +247,7 @@ SCRUB_FN(xfs_scrub_bmap_attr);
SCRUB_FN(xfs_scrub_bmap_cow);
SCRUB_FN(xfs_scrub_directory);
SCRUB_FN(xfs_scrub_xattr);
+SCRUB_FN(xfs_scrub_symlink);
#undef SCRUB_FN

#endif /* __XFS_REPAIR_COMMON_H__ */
diff --git a/fs/xfs/scrub/symlink.c b/fs/xfs/scrub/symlink.c
new file mode 100644
index 0000000..75537e9
--- /dev/null
+++ b/fs/xfs/scrub/symlink.c
@@ -0,0 +1,94 @@
+/*
+ * Copyright (C) 2017 Oracle. All Rights Reserved.
+ *
+ * Author: Darrick J. Wong <darrick.wong@oracle.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_mount.h"
+#include "xfs_defer.h"
+#include "xfs_btree.h"
+#include "xfs_bit.h"
+#include "xfs_log_format.h"
+#include "xfs_trans.h"
+#include "xfs_trace.h"
+#include "xfs_sb.h"
+#include "xfs_inode.h"
+#include "xfs_inode_fork.h"
+#include "xfs_symlink.h"
+#include "scrub/common.h"
+
+/* Set us up to scrub a symbolic link. */
+int
+xfs_scrub_setup_symlink(
+ struct xfs_scrub_context *sc,
+ struct xfs_inode *ip)
+{
+ /* Allocate the buffer without the inode lock held. */
+ sc->buf = kmem_zalloc_large(XFS_SYMLINK_MAXLEN + 1, KM_SLEEP);
+ if (!sc->buf)
+ return -ENOMEM;
+
+ return xfs_scrub_setup_inode_contents(sc, ip, 0);
+}
+
+/* Symbolic links. */
+
+#define XFS_SCRUB_SYMLINK_CHECK(fs_ok) \
+ XFS_SCRUB_INO_CHECK(sc, ip->i_ino, NULL, "symlink", fs_ok)
+#define XFS_SCRUB_SYMLINK_GOTO(fs_ok, label) \
+ XFS_SCRUB_INO_GOTO(sc, ip->i_ino, NULL, "symlink", fs_ok, label)
+int
+xfs_scrub_symlink(
+ struct xfs_scrub_context *sc)
+{
+ struct xfs_inode *ip = sc->ip;
+ struct xfs_ifork *ifp;
+ loff_t len;
+ int error = 0;
+
+ if (!S_ISLNK(VFS_I(ip)->i_mode))
+ return -ENOENT;
+ ifp = XFS_IFORK_PTR(ip, XFS_DATA_FORK);
+ len = ip->i_d.di_size;
+
+ /* Plausible size? */
+ XFS_SCRUB_SYMLINK_GOTO(len <= XFS_SYMLINK_MAXLEN, out);
+ XFS_SCRUB_SYMLINK_GOTO(len > 0, out);
+
+ /* Inline symlink? */
+ if (ifp->if_flags & XFS_IFINLINE) {
+ XFS_SCRUB_SYMLINK_GOTO(len > 0, out);
+ XFS_SCRUB_SYMLINK_CHECK(len <= XFS_IFORK_DSIZE(ip));
+ XFS_SCRUB_SYMLINK_CHECK(len <= strnlen(ifp->if_u1.if_data,
+ XFS_IFORK_DSIZE(ip)));
+ goto out;
+ }
+
+ /* Remote symlink; must read the contents. */
+ error = xfs_readlink_bmap_ilocked(sc->ip, sc->buf);
+ XFS_SCRUB_FILE_OP_ERROR_GOTO(sc, XFS_DATA_FORK, 0, "symlink",
+ &error, out);
+ XFS_SCRUB_SYMLINK_CHECK(len <= strnlen(sc->buf, XFS_SYMLINK_MAXLEN));
+out:
+ return error;
+}
+#undef XFS_SCRUB_SYMLINK_GOTO
+#undef XFS_SCRUB_SYMLINK_CHECK
diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h
index fe4b313..39824f8 100644
--- a/fs/xfs/xfs_trace.h
+++ b/fs/xfs/xfs_trace.h
@@ -3329,7 +3329,8 @@ DEFINE_GETFSMAP_EVENT(xfs_getfsmap_mapping);
{ XFS_SCRUB_TYPE_BMBTA, "bmapbta" }, \
{ XFS_SCRUB_TYPE_BMBTC, "bmapbtc" }, \
{ XFS_SCRUB_TYPE_DIR, "dir" }, \
- { XFS_SCRUB_TYPE_XATTR, "xattr" }
+ { XFS_SCRUB_TYPE_XATTR, "xattr" }, \
+ { XFS_SCRUB_TYPE_SYMLINK, "symlink" }
DECLARE_EVENT_CLASS(xfs_scrub_class,
TP_PROTO(struct xfs_inode *ip, struct xfs_scrub_metadata *sm,
int error),