Re: [PATCH 19/22] xfs: scrub symbolic links

Allison Henderson
2017-07-23T17:59:08Z

Looks good. Looks like you caught some bugs along the way
Reviewed by: Allison Henderson <allison.henderson@oracle.com>

On 7/20/2017 9:40 PM, Darrick J. Wong wrote:
> 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),
>
> --
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