From dcb660f9222fd9f607e7e05f4755b39b809ca19f Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Tue, 17 Oct 2017 21:37:36 -0700 Subject: [PATCH] xfs: probe the scrub ioctl Create a probe scrubber with id 0. This will be used by xfs_scrub to probe the kernel's abilities to scrub (and repair) the metadata. We do this by validating the ioctl inputs from userspace, preparing the filesystem for a scrub (or a repair) operation, and immediately returning to userspace. Userspace can use the returned errno and structure state to decide (in broad terms) if scrub/repair are supported by the running kernel. Signed-off-by: Darrick J. Wong Reviewed-by: Dave Chinner --- fs/xfs/Makefile | 1 + fs/xfs/libxfs/xfs_fs.h | 3 ++- fs/xfs/scrub/common.c | 59 ++++++++++++++++++++++++++++++++++++++++++ fs/xfs/scrub/common.h | 57 ++++++++++++++++++++++++++++++++++++++++ fs/xfs/scrub/scrub.c | 29 +++++++++++++++++++++ fs/xfs/scrub/scrub.h | 1 + fs/xfs/scrub/trace.c | 1 + 7 files changed, 150 insertions(+), 1 deletion(-) create mode 100644 fs/xfs/scrub/common.c create mode 100644 fs/xfs/scrub/common.h diff --git a/fs/xfs/Makefile b/fs/xfs/Makefile index 3e1f2fd30c48..924ad45e7442 100644 --- a/fs/xfs/Makefile +++ b/fs/xfs/Makefile @@ -143,6 +143,7 @@ ifeq ($(CONFIG_XFS_ONLINE_SCRUB),y) xfs-y += $(addprefix scrub/, \ trace.o \ + common.o \ scrub.o \ ) endif diff --git a/fs/xfs/libxfs/xfs_fs.h b/fs/xfs/libxfs/xfs_fs.h index 3b4a36e4b541..765f91e9c732 100644 --- a/fs/xfs/libxfs/xfs_fs.h +++ b/fs/xfs/libxfs/xfs_fs.h @@ -483,9 +483,10 @@ struct xfs_scrub_metadata { */ /* Scrub subcommands. */ +#define XFS_SCRUB_TYPE_PROBE 0 /* presence test ioctl */ /* Number of scrub subcommands. */ -#define XFS_SCRUB_TYPE_NR 0 +#define XFS_SCRUB_TYPE_NR 1 /* i: Repair this metadata. */ #define XFS_SCRUB_IFLAG_REPAIR (1 << 0) diff --git a/fs/xfs/scrub/common.c b/fs/xfs/scrub/common.c new file mode 100644 index 000000000000..d2c8f94fac0c --- /dev/null +++ b/fs/xfs/scrub/common.c @@ -0,0 +1,59 @@ +/* + * Copyright (C) 2017 Oracle. All Rights Reserved. + * + * Author: Darrick J. Wong + * + * 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_alloc.h" +#include "xfs_alloc_btree.h" +#include "xfs_bmap.h" +#include "xfs_bmap_btree.h" +#include "xfs_ialloc.h" +#include "xfs_ialloc_btree.h" +#include "xfs_refcount.h" +#include "xfs_refcount_btree.h" +#include "xfs_rmap.h" +#include "xfs_rmap_btree.h" +#include "scrub/xfs_scrub.h" +#include "scrub/scrub.h" +#include "scrub/common.h" +#include "scrub/trace.h" + +/* Common code for the metadata scrubbers. */ + +/* Per-scrubber setup functions */ + +/* Set us up with a transaction and an empty context. */ +int +xfs_scrub_setup_fs( + struct xfs_scrub_context *sc, + struct xfs_inode *ip) +{ + return xfs_scrub_trans_alloc(sc->sm, sc->mp, &sc->tp); +} diff --git a/fs/xfs/scrub/common.h b/fs/xfs/scrub/common.h new file mode 100644 index 000000000000..75ec4fa91b91 --- /dev/null +++ b/fs/xfs/scrub/common.h @@ -0,0 +1,57 @@ +/* + * Copyright (C) 2017 Oracle. All Rights Reserved. + * + * Author: Darrick J. Wong + * + * 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. + */ +#ifndef __XFS_SCRUB_COMMON_H__ +#define __XFS_SCRUB_COMMON_H__ + +/* + * We /could/ terminate a scrub/repair operation early. If we're not + * in a good place to continue (fatal signal, etc.) then bail out. + * Note that we're careful not to make any judgements about *error. + */ +static inline bool +xfs_scrub_should_terminate( + struct xfs_scrub_context *sc, + int *error) +{ + if (fatal_signal_pending(current)) { + if (*error == 0) + *error = -EAGAIN; + return true; + } + return false; +} + +/* + * Grab an empty transaction so that we can re-grab locked buffers if + * one of our btrees turns out to be cyclic. + */ +static inline int +xfs_scrub_trans_alloc( + struct xfs_scrub_metadata *sm, + struct xfs_mount *mp, + struct xfs_trans **tpp) +{ + return xfs_trans_alloc_empty(mp, tpp); +} + +/* Setup functions */ +int xfs_scrub_setup_fs(struct xfs_scrub_context *sc, struct xfs_inode *ip); + +#endif /* __XFS_SCRUB_COMMON_H__ */ diff --git a/fs/xfs/scrub/scrub.c b/fs/xfs/scrub/scrub.c index 1fc8d3b43902..71183a8678aa 100644 --- a/fs/xfs/scrub/scrub.c +++ b/fs/xfs/scrub/scrub.c @@ -42,6 +42,7 @@ #include "xfs_rmap_btree.h" #include "scrub/xfs_scrub.h" #include "scrub/scrub.h" +#include "scrub/common.h" #include "scrub/trace.h" /* @@ -108,6 +109,30 @@ * will be set. */ +/* + * Scrub probe -- userspace uses this to probe if we're willing to scrub + * or repair a given mountpoint. This will be used by xfs_scrub to + * probe the kernel's abilities to scrub (and repair) the metadata. We + * do this by validating the ioctl inputs from userspace, preparing the + * filesystem for a scrub (or a repair) operation, and immediately + * returning to userspace. Userspace can use the returned errno and + * structure state to decide (in broad terms) if scrub/repair are + * supported by the running kernel. + */ +int +xfs_scrub_probe( + struct xfs_scrub_context *sc) +{ + int error = 0; + + if (sc->sm->sm_ino || sc->sm->sm_agno) + return -EINVAL; + if (xfs_scrub_should_terminate(sc, &error)) + return error; + + return 0; +} + /* Scrub setup and teardown */ /* Free all the resources and finish the transactions. */ @@ -126,6 +151,10 @@ xfs_scrub_teardown( /* Scrubbing dispatch. */ static const struct xfs_scrub_meta_ops meta_scrub_ops[] = { + { /* ioctl presence test */ + .setup = xfs_scrub_setup_fs, + .scrub = xfs_scrub_probe, + }, }; /* This isn't a stable feature, warn once per day. */ diff --git a/fs/xfs/scrub/scrub.h b/fs/xfs/scrub/scrub.h index ef7b50e33c93..b7b94220d929 100644 --- a/fs/xfs/scrub/scrub.h +++ b/fs/xfs/scrub/scrub.h @@ -45,5 +45,6 @@ struct xfs_scrub_context { }; /* Metadata scrubbers */ +int xfs_scrub_tester(struct xfs_scrub_context *sc); #endif /* __XFS_SCRUB_SCRUB_H__ */ diff --git a/fs/xfs/scrub/trace.c b/fs/xfs/scrub/trace.c index c59fd41b969d..88b5ccb5df07 100644 --- a/fs/xfs/scrub/trace.c +++ b/fs/xfs/scrub/trace.c @@ -32,6 +32,7 @@ #include "xfs_trans.h" #include "scrub/xfs_scrub.h" #include "scrub/scrub.h" +#include "scrub/common.h" /* * We include this last to have the helpers above available for the trace