[PATCH 24/27] xfs: scrub symbolic links

Darrick J. Wong
2017-09-21T00:20:12Z

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.h | 2 +
fs/xfs/scrub/scrub.c | 4 ++
fs/xfs/scrub/scrub.h | 1 +
fs/xfs/scrub/symlink.c | 92 ++++++++++++++++++++++++++++++++++++++++++++++++
6 files changed, 102 insertions(+), 1 deletion(-)
create mode 100644 fs/xfs/scrub/symlink.c

diff --git a/fs/xfs/Makefile b/fs/xfs/Makefile
index 4d46399..28637a6 100644
--- a/fs/xfs/Makefile
+++ b/fs/xfs/Makefile
@@ -159,5 +159,6 @@ xfs-y += $(addprefix scrub/, \
refcount.o \
rmap.o \
scrub.o \
+ symlink.o \
)
endif
diff --git a/fs/xfs/libxfs/xfs_fs.h b/fs/xfs/libxfs/xfs_fs.h
index d31d743..955eea7 100644
--- a/fs/xfs/libxfs/xfs_fs.h
+++ b/fs/xfs/libxfs/xfs_fs.h
@@ -500,9 +500,10 @@ struct xfs_scrub_metadata {
#define XFS_SCRUB_TYPE_BMBTC 14 /* CoW fork block mapping */
#define XFS_SCRUB_TYPE_DIR 15 /* directory */
#define XFS_SCRUB_TYPE_XATTR 16 /* extended attribute */
+#define XFS_SCRUB_TYPE_SYMLINK 17 /* symbolic link */

/* Number of scrub subcommands. */
-#define XFS_SCRUB_TYPE_NR 17
+#define XFS_SCRUB_TYPE_NR 18

/* i: Repair this metadata. */
#define XFS_SCRUB_IFLAG_REPAIR (1 << 0)
diff --git a/fs/xfs/scrub/common.h b/fs/xfs/scrub/common.h
index f0a33b3..eeb6bc4 100644
--- a/fs/xfs/scrub/common.h
+++ b/fs/xfs/scrub/common.h
@@ -112,6 +112,8 @@ int xfs_scrub_setup_directory(struct xfs_scrub_context *sc,
struct xfs_inode *ip);
int xfs_scrub_setup_xattr(struct xfs_scrub_context *sc,
struct xfs_inode *ip);
+int xfs_scrub_setup_symlink(struct xfs_scrub_context *sc,
+ struct xfs_inode *ip);

void xfs_scrub_ag_free(struct xfs_scrub_context *sc, struct xfs_scrub_ag *sa);
int xfs_scrub_ag_init(struct xfs_scrub_context *sc, xfs_agnumber_t agno,
diff --git a/fs/xfs/scrub/scrub.c b/fs/xfs/scrub/scrub.c
index 046b3e5..0185a61 100644
--- a/fs/xfs/scrub/scrub.c
+++ b/fs/xfs/scrub/scrub.c
@@ -242,6 +242,10 @@ static const struct xfs_scrub_meta_ops meta_scrub_ops[] = {
.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/scrub.h b/fs/xfs/scrub/scrub.h
index b440e26..89dfb66 100644
--- a/fs/xfs/scrub/scrub.h
+++ b/fs/xfs/scrub/scrub.h
@@ -80,5 +80,6 @@ int xfs_scrub_bmap_attr(struct xfs_scrub_context *sc);
int xfs_scrub_bmap_cow(struct xfs_scrub_context *sc);
int xfs_scrub_directory(struct xfs_scrub_context *sc);
int xfs_scrub_xattr(struct xfs_scrub_context *sc);
+int xfs_scrub_symlink(struct xfs_scrub_context *sc);

#endif /* __XFS_SCRUB_SCRUB_H__ */
diff --git a/fs/xfs/scrub/symlink.c b/fs/xfs/scrub/symlink.c
new file mode 100644
index 0000000..e3b5d35
--- /dev/null
+++ b/fs/xfs/scrub/symlink.c
@@ -0,0 +1,92 @@
+/*
+ * 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_sb.h"
+#include "xfs_inode.h"
+#include "xfs_inode_fork.h"
+#include "xfs_symlink.h"
+#include "scrub/xfs_scrub.h"
+#include "scrub/scrub.h"
+#include "scrub/common.h"
+#include "scrub/trace.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. */
+
+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? */
+ if (!xfs_scrub_fblock_check_ok(sc, XFS_DATA_FORK, 0,
+ len <= XFS_SYMLINK_MAXLEN && len > 0))
+ goto out;
+
+ /* Inline symlink? */
+ if (ifp->if_flags & XFS_IFINLINE) {
+ xfs_scrub_fblock_check_ok(sc, XFS_DATA_FORK, 0,
+ len <= XFS_IFORK_DSIZE(ip) &&
+ 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);
+ if (!xfs_scrub_fblock_op_ok(sc, XFS_DATA_FORK, 0, &error))
+ goto out;
+ xfs_scrub_fblock_check_ok(sc, XFS_DATA_FORK, 0,
+ len <= strnlen(sc->buf, XFS_SYMLINK_MAXLEN));
+out:
+ return error;
+}