[Feature] add GA346 baseline version
Change-Id: Ic62933698569507dcf98240cdf5d9931ae34348f
diff --git a/src/kernel/linux/v4.19/fs/xfs/scrub/scrub.c b/src/kernel/linux/v4.19/fs/xfs/scrub/scrub.c
new file mode 100644
index 0000000..4bfae1e
--- /dev/null
+++ b/src/kernel/linux/v4.19/fs/xfs/scrub/scrub.c
@@ -0,0 +1,582 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2017 Oracle. All Rights Reserved.
+ * Author: Darrick J. Wong <darrick.wong@oracle.com>
+ */
+#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_icache.h"
+#include "xfs_itable.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 "xfs_quota.h"
+#include "xfs_qm.h"
+#include "xfs_errortag.h"
+#include "xfs_error.h"
+#include "xfs_log.h"
+#include "xfs_trans_priv.h"
+#include "scrub/xfs_scrub.h"
+#include "scrub/scrub.h"
+#include "scrub/common.h"
+#include "scrub/trace.h"
+#include "scrub/btree.h"
+#include "scrub/repair.h"
+
+/*
+ * Online Scrub and Repair
+ *
+ * Traditionally, XFS (the kernel driver) did not know how to check or
+ * repair on-disk data structures. That task was left to the xfs_check
+ * and xfs_repair tools, both of which require taking the filesystem
+ * offline for a thorough but time consuming examination. Online
+ * scrub & repair, on the other hand, enables us to check the metadata
+ * for obvious errors while carefully stepping around the filesystem's
+ * ongoing operations, locking rules, etc.
+ *
+ * Given that most XFS metadata consist of records stored in a btree,
+ * most of the checking functions iterate the btree blocks themselves
+ * looking for irregularities. When a record block is encountered, each
+ * record can be checked for obviously bad values. Record values can
+ * also be cross-referenced against other btrees to look for potential
+ * misunderstandings between pieces of metadata.
+ *
+ * It is expected that the checkers responsible for per-AG metadata
+ * structures will lock the AG headers (AGI, AGF, AGFL), iterate the
+ * metadata structure, and perform any relevant cross-referencing before
+ * unlocking the AG and returning the results to userspace. These
+ * scrubbers must not keep an AG locked for too long to avoid tying up
+ * the block and inode allocators.
+ *
+ * Block maps and b-trees rooted in an inode present a special challenge
+ * because they can involve extents from any AG. The general scrubber
+ * structure of lock -> check -> xref -> unlock still holds, but AG
+ * locking order rules /must/ be obeyed to avoid deadlocks. The
+ * ordering rule, of course, is that we must lock in increasing AG
+ * order. Helper functions are provided to track which AG headers we've
+ * already locked. If we detect an imminent locking order violation, we
+ * can signal a potential deadlock, in which case the scrubber can jump
+ * out to the top level, lock all the AGs in order, and retry the scrub.
+ *
+ * For file data (directories, extended attributes, symlinks) scrub, we
+ * can simply lock the inode and walk the data. For btree data
+ * (directories and attributes) we follow the same btree-scrubbing
+ * strategy outlined previously to check the records.
+ *
+ * We use a bit of trickery with transactions to avoid buffer deadlocks
+ * if there is a cycle in the metadata. The basic problem is that
+ * travelling down a btree involves locking the current buffer at each
+ * tree level. If a pointer should somehow point back to a buffer that
+ * we've already examined, we will deadlock due to the second buffer
+ * locking attempt. Note however that grabbing a buffer in transaction
+ * context links the locked buffer to the transaction. If we try to
+ * re-grab the buffer in the context of the same transaction, we avoid
+ * the second lock attempt and continue. Between the verifier and the
+ * scrubber, something will notice that something is amiss and report
+ * the corruption. Therefore, each scrubber will allocate an empty
+ * transaction, attach buffers to it, and cancel the transaction at the
+ * end of the scrub run. Cancelling a non-dirty transaction simply
+ * unlocks the buffers.
+ *
+ * There are four pieces of data that scrub can communicate to
+ * userspace. The first is the error code (errno), which can be used to
+ * communicate operational errors in performing the scrub. There are
+ * also three flags that can be set in the scrub context. If the data
+ * structure itself is corrupt, the CORRUPT flag will be set. If
+ * the metadata is correct but otherwise suboptimal, the PREEN flag
+ * will be set.
+ *
+ * We perform secondary validation of filesystem metadata by
+ * cross-referencing every record with all other available metadata.
+ * For example, for block mapping extents, we verify that there are no
+ * records in the free space and inode btrees corresponding to that
+ * space extent and that there is a corresponding entry in the reverse
+ * mapping btree. Inconsistent metadata is noted by setting the
+ * XCORRUPT flag; btree query function errors are noted by setting the
+ * XFAIL flag and deleting the cursor to prevent further attempts to
+ * cross-reference with a defective btree.
+ *
+ * If a piece of metadata proves corrupt or suboptimal, the userspace
+ * program can ask the kernel to apply some tender loving care (TLC) to
+ * the metadata object by setting the REPAIR flag and re-calling the
+ * scrub ioctl. "Corruption" is defined by metadata violating the
+ * on-disk specification; operations cannot continue if the violation is
+ * left untreated. It is possible for XFS to continue if an object is
+ * "suboptimal", however performance may be degraded. Repairs are
+ * usually performed by rebuilding the metadata entirely out of
+ * redundant metadata. Optimizing, on the other hand, can sometimes be
+ * done without rebuilding entire structures.
+ *
+ * Generally speaking, the repair code has the following code structure:
+ * Lock -> scrub -> repair -> commit -> re-lock -> re-scrub -> unlock.
+ * The first check helps us figure out if we need to rebuild or simply
+ * optimize the structure so that the rebuild knows what to do. The
+ * second check evaluates the completeness of the repair; that is what
+ * is reported to userspace.
+ *
+ * A quick note on symbol prefixes:
+ * - "xfs_" are general XFS symbols.
+ * - "xchk_" are symbols related to metadata checking.
+ * - "xrep_" are symbols related to metadata repair.
+ * - "xfs_scrub_" are symbols that tie online fsck to the rest of XFS.
+ */
+
+/*
+ * 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.
+ */
+static int
+xchk_probe(
+ struct xfs_scrub *sc)
+{
+ int error = 0;
+
+ if (xchk_should_terminate(sc, &error))
+ return error;
+
+ return 0;
+}
+
+/* Scrub setup and teardown */
+
+/* Free all the resources and finish the transactions. */
+STATIC int
+xchk_teardown(
+ struct xfs_scrub *sc,
+ struct xfs_inode *ip_in,
+ int error)
+{
+ xchk_ag_free(sc, &sc->sa);
+ if (sc->tp) {
+ if (error == 0 && (sc->sm->sm_flags & XFS_SCRUB_IFLAG_REPAIR))
+ error = xfs_trans_commit(sc->tp);
+ else
+ xfs_trans_cancel(sc->tp);
+ sc->tp = NULL;
+ }
+ if (sc->ip) {
+ if (sc->ilock_flags)
+ xfs_iunlock(sc->ip, sc->ilock_flags);
+ if (sc->ip != ip_in &&
+ !xfs_internal_inum(sc->mp, sc->ip->i_ino))
+ xfs_irele(sc->ip);
+ sc->ip = NULL;
+ }
+ if (sc->has_quotaofflock)
+ mutex_unlock(&sc->mp->m_quotainfo->qi_quotaofflock);
+ if (sc->buf) {
+ kmem_free(sc->buf);
+ sc->buf = NULL;
+ }
+ return error;
+}
+
+/* Scrubbing dispatch. */
+
+static const struct xchk_meta_ops meta_scrub_ops[] = {
+ [XFS_SCRUB_TYPE_PROBE] = { /* ioctl presence test */
+ .type = ST_NONE,
+ .setup = xchk_setup_fs,
+ .scrub = xchk_probe,
+ .repair = xrep_probe,
+ },
+ [XFS_SCRUB_TYPE_SB] = { /* superblock */
+ .type = ST_PERAG,
+ .setup = xchk_setup_fs,
+ .scrub = xchk_superblock,
+ .repair = xrep_superblock,
+ },
+ [XFS_SCRUB_TYPE_AGF] = { /* agf */
+ .type = ST_PERAG,
+ .setup = xchk_setup_fs,
+ .scrub = xchk_agf,
+ .repair = xrep_agf,
+ },
+ [XFS_SCRUB_TYPE_AGFL]= { /* agfl */
+ .type = ST_PERAG,
+ .setup = xchk_setup_fs,
+ .scrub = xchk_agfl,
+ .repair = xrep_agfl,
+ },
+ [XFS_SCRUB_TYPE_AGI] = { /* agi */
+ .type = ST_PERAG,
+ .setup = xchk_setup_fs,
+ .scrub = xchk_agi,
+ .repair = xrep_agi,
+ },
+ [XFS_SCRUB_TYPE_BNOBT] = { /* bnobt */
+ .type = ST_PERAG,
+ .setup = xchk_setup_ag_allocbt,
+ .scrub = xchk_bnobt,
+ .repair = xrep_notsupported,
+ },
+ [XFS_SCRUB_TYPE_CNTBT] = { /* cntbt */
+ .type = ST_PERAG,
+ .setup = xchk_setup_ag_allocbt,
+ .scrub = xchk_cntbt,
+ .repair = xrep_notsupported,
+ },
+ [XFS_SCRUB_TYPE_INOBT] = { /* inobt */
+ .type = ST_PERAG,
+ .setup = xchk_setup_ag_iallocbt,
+ .scrub = xchk_inobt,
+ .repair = xrep_notsupported,
+ },
+ [XFS_SCRUB_TYPE_FINOBT] = { /* finobt */
+ .type = ST_PERAG,
+ .setup = xchk_setup_ag_iallocbt,
+ .scrub = xchk_finobt,
+ .has = xfs_sb_version_hasfinobt,
+ .repair = xrep_notsupported,
+ },
+ [XFS_SCRUB_TYPE_RMAPBT] = { /* rmapbt */
+ .type = ST_PERAG,
+ .setup = xchk_setup_ag_rmapbt,
+ .scrub = xchk_rmapbt,
+ .has = xfs_sb_version_hasrmapbt,
+ .repair = xrep_notsupported,
+ },
+ [XFS_SCRUB_TYPE_REFCNTBT] = { /* refcountbt */
+ .type = ST_PERAG,
+ .setup = xchk_setup_ag_refcountbt,
+ .scrub = xchk_refcountbt,
+ .has = xfs_sb_version_hasreflink,
+ .repair = xrep_notsupported,
+ },
+ [XFS_SCRUB_TYPE_INODE] = { /* inode record */
+ .type = ST_INODE,
+ .setup = xchk_setup_inode,
+ .scrub = xchk_inode,
+ .repair = xrep_notsupported,
+ },
+ [XFS_SCRUB_TYPE_BMBTD] = { /* inode data fork */
+ .type = ST_INODE,
+ .setup = xchk_setup_inode_bmap,
+ .scrub = xchk_bmap_data,
+ .repair = xrep_notsupported,
+ },
+ [XFS_SCRUB_TYPE_BMBTA] = { /* inode attr fork */
+ .type = ST_INODE,
+ .setup = xchk_setup_inode_bmap,
+ .scrub = xchk_bmap_attr,
+ .repair = xrep_notsupported,
+ },
+ [XFS_SCRUB_TYPE_BMBTC] = { /* inode CoW fork */
+ .type = ST_INODE,
+ .setup = xchk_setup_inode_bmap,
+ .scrub = xchk_bmap_cow,
+ .repair = xrep_notsupported,
+ },
+ [XFS_SCRUB_TYPE_DIR] = { /* directory */
+ .type = ST_INODE,
+ .setup = xchk_setup_directory,
+ .scrub = xchk_directory,
+ .repair = xrep_notsupported,
+ },
+ [XFS_SCRUB_TYPE_XATTR] = { /* extended attributes */
+ .type = ST_INODE,
+ .setup = xchk_setup_xattr,
+ .scrub = xchk_xattr,
+ .repair = xrep_notsupported,
+ },
+ [XFS_SCRUB_TYPE_SYMLINK] = { /* symbolic link */
+ .type = ST_INODE,
+ .setup = xchk_setup_symlink,
+ .scrub = xchk_symlink,
+ .repair = xrep_notsupported,
+ },
+ [XFS_SCRUB_TYPE_PARENT] = { /* parent pointers */
+ .type = ST_INODE,
+ .setup = xchk_setup_parent,
+ .scrub = xchk_parent,
+ .repair = xrep_notsupported,
+ },
+ [XFS_SCRUB_TYPE_RTBITMAP] = { /* realtime bitmap */
+ .type = ST_FS,
+ .setup = xchk_setup_rt,
+ .scrub = xchk_rtbitmap,
+ .has = xfs_sb_version_hasrealtime,
+ .repair = xrep_notsupported,
+ },
+ [XFS_SCRUB_TYPE_RTSUM] = { /* realtime summary */
+ .type = ST_FS,
+ .setup = xchk_setup_rt,
+ .scrub = xchk_rtsummary,
+ .has = xfs_sb_version_hasrealtime,
+ .repair = xrep_notsupported,
+ },
+ [XFS_SCRUB_TYPE_UQUOTA] = { /* user quota */
+ .type = ST_FS,
+ .setup = xchk_setup_quota,
+ .scrub = xchk_quota,
+ .repair = xrep_notsupported,
+ },
+ [XFS_SCRUB_TYPE_GQUOTA] = { /* group quota */
+ .type = ST_FS,
+ .setup = xchk_setup_quota,
+ .scrub = xchk_quota,
+ .repair = xrep_notsupported,
+ },
+ [XFS_SCRUB_TYPE_PQUOTA] = { /* project quota */
+ .type = ST_FS,
+ .setup = xchk_setup_quota,
+ .scrub = xchk_quota,
+ .repair = xrep_notsupported,
+ },
+};
+
+/* This isn't a stable feature, warn once per day. */
+static inline void
+xchk_experimental_warning(
+ struct xfs_mount *mp)
+{
+ static struct ratelimit_state scrub_warning = RATELIMIT_STATE_INIT(
+ "xchk_warning", 86400 * HZ, 1);
+ ratelimit_set_flags(&scrub_warning, RATELIMIT_MSG_ON_RELEASE);
+
+ if (__ratelimit(&scrub_warning))
+ xfs_alert(mp,
+"EXPERIMENTAL online scrub feature in use. Use at your own risk!");
+}
+
+static int
+xchk_validate_inputs(
+ struct xfs_mount *mp,
+ struct xfs_scrub_metadata *sm)
+{
+ int error;
+ const struct xchk_meta_ops *ops;
+
+ error = -EINVAL;
+ /* Check our inputs. */
+ sm->sm_flags &= ~XFS_SCRUB_FLAGS_OUT;
+ if (sm->sm_flags & ~XFS_SCRUB_FLAGS_IN)
+ goto out;
+ /* sm_reserved[] must be zero */
+ if (memchr_inv(sm->sm_reserved, 0, sizeof(sm->sm_reserved)))
+ goto out;
+
+ error = -ENOENT;
+ /* Do we know about this type of metadata? */
+ if (sm->sm_type >= XFS_SCRUB_TYPE_NR)
+ goto out;
+ ops = &meta_scrub_ops[sm->sm_type];
+ if (ops->setup == NULL || ops->scrub == NULL)
+ goto out;
+ /* Does this fs even support this type of metadata? */
+ if (ops->has && !ops->has(&mp->m_sb))
+ goto out;
+
+ error = -EINVAL;
+ /* restricting fields must be appropriate for type */
+ switch (ops->type) {
+ case ST_NONE:
+ case ST_FS:
+ if (sm->sm_ino || sm->sm_gen || sm->sm_agno)
+ goto out;
+ break;
+ case ST_PERAG:
+ if (sm->sm_ino || sm->sm_gen ||
+ sm->sm_agno >= mp->m_sb.sb_agcount)
+ goto out;
+ break;
+ case ST_INODE:
+ if (sm->sm_agno || (sm->sm_gen && !sm->sm_ino))
+ goto out;
+ break;
+ default:
+ goto out;
+ }
+
+ error = -EOPNOTSUPP;
+ /*
+ * We won't scrub any filesystem that doesn't have the ability
+ * to record unwritten extents. The option was made default in
+ * 2003, removed from mkfs in 2007, and cannot be disabled in
+ * v5, so if we find a filesystem without this flag it's either
+ * really old or totally unsupported. Avoid it either way.
+ * We also don't support v1-v3 filesystems, which aren't
+ * mountable.
+ */
+ if (!xfs_sb_version_hasextflgbit(&mp->m_sb))
+ goto out;
+
+ /*
+ * We only want to repair read-write v5+ filesystems. Defer the check
+ * for ops->repair until after our scrub confirms that we need to
+ * perform repairs so that we avoid failing due to not supporting
+ * repairing an object that doesn't need repairs.
+ */
+ if (sm->sm_flags & XFS_SCRUB_IFLAG_REPAIR) {
+ error = -EOPNOTSUPP;
+ if (!xfs_sb_version_hascrc(&mp->m_sb))
+ goto out;
+
+ error = -EROFS;
+ if (mp->m_flags & XFS_MOUNT_RDONLY)
+ goto out;
+ }
+
+ error = 0;
+out:
+ return error;
+}
+
+#ifdef CONFIG_XFS_ONLINE_REPAIR
+static inline void xchk_postmortem(struct xfs_scrub *sc)
+{
+ /*
+ * Userspace asked us to repair something, we repaired it, rescanned
+ * it, and the rescan says it's still broken. Scream about this in
+ * the system logs.
+ */
+ if ((sc->sm->sm_flags & XFS_SCRUB_IFLAG_REPAIR) &&
+ (sc->sm->sm_flags & (XFS_SCRUB_OFLAG_CORRUPT |
+ XFS_SCRUB_OFLAG_XCORRUPT)))
+ xrep_failure(sc->mp);
+}
+#else
+static inline void xchk_postmortem(struct xfs_scrub *sc)
+{
+ /*
+ * Userspace asked us to scrub something, it's broken, and we have no
+ * way of fixing it. Scream in the logs.
+ */
+ if (sc->sm->sm_flags & (XFS_SCRUB_OFLAG_CORRUPT |
+ XFS_SCRUB_OFLAG_XCORRUPT))
+ xfs_alert_ratelimited(sc->mp,
+ "Corruption detected during scrub.");
+}
+#endif /* CONFIG_XFS_ONLINE_REPAIR */
+
+/* Dispatch metadata scrubbing. */
+int
+xfs_scrub_metadata(
+ struct xfs_inode *ip,
+ struct xfs_scrub_metadata *sm)
+{
+ struct xfs_scrub sc;
+ struct xfs_mount *mp = ip->i_mount;
+ bool try_harder = false;
+ bool already_fixed = false;
+ int error = 0;
+
+ BUILD_BUG_ON(sizeof(meta_scrub_ops) !=
+ (sizeof(struct xchk_meta_ops) * XFS_SCRUB_TYPE_NR));
+
+ trace_xchk_start(ip, sm, error);
+
+ /* Forbidden if we are shut down or mounted norecovery. */
+ error = -ESHUTDOWN;
+ if (XFS_FORCED_SHUTDOWN(mp))
+ goto out;
+ error = -ENOTRECOVERABLE;
+ if (mp->m_flags & XFS_MOUNT_NORECOVERY)
+ goto out;
+
+ error = xchk_validate_inputs(mp, sm);
+ if (error)
+ goto out;
+
+ xchk_experimental_warning(mp);
+
+retry_op:
+ /* Set up for the operation. */
+ memset(&sc, 0, sizeof(sc));
+ sc.mp = ip->i_mount;
+ sc.sm = sm;
+ sc.ops = &meta_scrub_ops[sm->sm_type];
+ sc.try_harder = try_harder;
+ sc.sa.agno = NULLAGNUMBER;
+ error = sc.ops->setup(&sc, ip);
+ if (error)
+ goto out_teardown;
+
+ /* Scrub for errors. */
+ error = sc.ops->scrub(&sc);
+ if (!try_harder && error == -EDEADLOCK) {
+ /*
+ * Scrubbers return -EDEADLOCK to mean 'try harder'.
+ * Tear down everything we hold, then set up again with
+ * preparation for worst-case scenarios.
+ */
+ error = xchk_teardown(&sc, ip, 0);
+ if (error)
+ goto out;
+ try_harder = true;
+ goto retry_op;
+ } else if (error)
+ goto out_teardown;
+
+ if ((sc.sm->sm_flags & XFS_SCRUB_IFLAG_REPAIR) && !already_fixed) {
+ bool needs_fix;
+
+ /* Let debug users force us into the repair routines. */
+ if (XFS_TEST_ERROR(false, mp, XFS_ERRTAG_FORCE_SCRUB_REPAIR))
+ sc.sm->sm_flags |= XFS_SCRUB_OFLAG_CORRUPT;
+
+ needs_fix = (sc.sm->sm_flags & (XFS_SCRUB_OFLAG_CORRUPT |
+ XFS_SCRUB_OFLAG_XCORRUPT |
+ XFS_SCRUB_OFLAG_PREEN));
+ /*
+ * If userspace asked for a repair but it wasn't necessary,
+ * report that back to userspace.
+ */
+ if (!needs_fix) {
+ sc.sm->sm_flags |= XFS_SCRUB_OFLAG_NO_REPAIR_NEEDED;
+ goto out_nofix;
+ }
+
+ /*
+ * If it's broken, userspace wants us to fix it, and we haven't
+ * already tried to fix it, then attempt a repair.
+ */
+ error = xrep_attempt(ip, &sc, &already_fixed);
+ if (error == -EAGAIN) {
+ if (sc.try_harder)
+ try_harder = true;
+ error = xchk_teardown(&sc, ip, 0);
+ if (error) {
+ xrep_failure(mp);
+ goto out;
+ }
+ goto retry_op;
+ }
+ }
+
+out_nofix:
+ xchk_postmortem(&sc);
+out_teardown:
+ error = xchk_teardown(&sc, ip, error);
+out:
+ trace_xchk_done(ip, sm, error);
+ if (error == -EFSCORRUPTED || error == -EFSBADCRC) {
+ sm->sm_flags |= XFS_SCRUB_OFLAG_CORRUPT;
+ error = 0;
+ }
+ return error;
+}