diff options
| -rw-r--r-- | fs/xfs/Makefile | 1 | ||||
| -rw-r--r-- | fs/xfs/libxfs/xfs_fs.h | 3 | ||||
| -rw-r--r-- | fs/xfs/libxfs/xfs_types.c | 2 | ||||
| -rw-r--r-- | fs/xfs/libxfs/xfs_types.h | 2 | ||||
| -rw-r--r-- | fs/xfs/scrub/common.c | 9 | ||||
| -rw-r--r-- | fs/xfs/scrub/common.h | 2 | ||||
| -rw-r--r-- | fs/xfs/scrub/fscounters.c | 366 | ||||
| -rw-r--r-- | fs/xfs/scrub/health.c | 1 | ||||
| -rw-r--r-- | fs/xfs/scrub/scrub.c | 6 | ||||
| -rw-r--r-- | fs/xfs/scrub/scrub.h | 9 | ||||
| -rw-r--r-- | fs/xfs/scrub/trace.h | 63 |
11 files changed, 461 insertions, 3 deletions
diff --git a/fs/xfs/Makefile b/fs/xfs/Makefile index b20964e26a22..1dfc6df2e2bd 100644 --- a/fs/xfs/Makefile +++ b/fs/xfs/Makefile @@ -143,6 +143,7 @@ xfs-y += $(addprefix scrub/, \ common.o \ dabtree.o \ dir.o \ + fscounters.o \ health.o \ ialloc.o \ inode.o \ diff --git a/fs/xfs/libxfs/xfs_fs.h b/fs/xfs/libxfs/xfs_fs.h index 43a53b03247b..e7382c780ed7 100644 --- a/fs/xfs/libxfs/xfs_fs.h +++ b/fs/xfs/libxfs/xfs_fs.h @@ -578,9 +578,10 @@ struct xfs_scrub_metadata { #define XFS_SCRUB_TYPE_UQUOTA 21 /* user quotas */ #define XFS_SCRUB_TYPE_GQUOTA 22 /* group quotas */ #define XFS_SCRUB_TYPE_PQUOTA 23 /* project quotas */ +#define XFS_SCRUB_TYPE_FSCOUNTERS 24 /* fs summary counters */ /* Number of scrub subcommands. */ -#define XFS_SCRUB_TYPE_NR 24 +#define XFS_SCRUB_TYPE_NR 25 /* i: Repair this metadata. */ #define XFS_SCRUB_IFLAG_REPAIR (1 << 0) diff --git a/fs/xfs/libxfs/xfs_types.c b/fs/xfs/libxfs/xfs_types.c index de310712dd6d..d51acc95bc00 100644 --- a/fs/xfs/libxfs/xfs_types.c +++ b/fs/xfs/libxfs/xfs_types.c @@ -185,7 +185,7 @@ xfs_verify_rtbno( } /* Calculate the range of valid icount values. */ -static void +void xfs_icount_range( struct xfs_mount *mp, unsigned long long *min, diff --git a/fs/xfs/libxfs/xfs_types.h b/fs/xfs/libxfs/xfs_types.h index c5a25403b4db..802b34cd10fe 100644 --- a/fs/xfs/libxfs/xfs_types.h +++ b/fs/xfs/libxfs/xfs_types.h @@ -191,5 +191,7 @@ bool xfs_verify_dir_ino(struct xfs_mount *mp, xfs_ino_t ino); bool xfs_verify_rtbno(struct xfs_mount *mp, xfs_rtblock_t rtbno); bool xfs_verify_icount(struct xfs_mount *mp, unsigned long long icount); bool xfs_verify_dablk(struct xfs_mount *mp, xfs_fileoff_t off); +void xfs_icount_range(struct xfs_mount *mp, unsigned long long *min, + unsigned long long *max); #endif /* __XFS_TYPES_H__ */ diff --git a/fs/xfs/scrub/common.c b/fs/xfs/scrub/common.c index 7d7e91a7bb86..973aa59975e3 100644 --- a/fs/xfs/scrub/common.c +++ b/fs/xfs/scrub/common.c @@ -209,6 +209,15 @@ xchk_ino_set_preen( trace_xchk_ino_preen(sc, ino, __return_address); } +/* Record something being wrong with the filesystem primary superblock. */ +void +xchk_set_corrupt( + struct xfs_scrub *sc) +{ + sc->sm->sm_flags |= XFS_SCRUB_OFLAG_CORRUPT; + trace_xchk_fs_error(sc, 0, __return_address); +} + /* Record a corrupt block. */ void xchk_block_set_corrupt( diff --git a/fs/xfs/scrub/common.h b/fs/xfs/scrub/common.h index 84900bfad852..003a772cd26c 100644 --- a/fs/xfs/scrub/common.h +++ b/fs/xfs/scrub/common.h @@ -39,6 +39,7 @@ void xchk_block_set_preen(struct xfs_scrub *sc, struct xfs_buf *bp); void xchk_ino_set_preen(struct xfs_scrub *sc, xfs_ino_t ino); +void xchk_set_corrupt(struct xfs_scrub *sc); void xchk_block_set_corrupt(struct xfs_scrub *sc, struct xfs_buf *bp); void xchk_ino_set_corrupt(struct xfs_scrub *sc, xfs_ino_t ino); @@ -105,6 +106,7 @@ xchk_setup_quota(struct xfs_scrub *sc, struct xfs_inode *ip) return -ENOENT; } #endif +int xchk_setup_fscounters(struct xfs_scrub *sc, struct xfs_inode *ip); void xchk_ag_free(struct xfs_scrub *sc, struct xchk_ag *sa); int xchk_ag_init(struct xfs_scrub *sc, xfs_agnumber_t agno, diff --git a/fs/xfs/scrub/fscounters.c b/fs/xfs/scrub/fscounters.c new file mode 100644 index 000000000000..07c11e3e6437 --- /dev/null +++ b/fs/xfs/scrub/fscounters.c @@ -0,0 +1,366 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2019 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_alloc.h" +#include "xfs_ialloc.h" +#include "xfs_rmap.h" +#include "xfs_error.h" +#include "xfs_errortag.h" +#include "xfs_icache.h" +#include "xfs_health.h" +#include "xfs_bmap.h" +#include "scrub/xfs_scrub.h" +#include "scrub/scrub.h" +#include "scrub/common.h" +#include "scrub/trace.h" + +/* + * FS Summary Counters + * =================== + * + * The basics of filesystem summary counter checking are that we iterate the + * AGs counting the number of free blocks, free space btree blocks, per-AG + * reservations, inodes, delayed allocation reservations, and free inodes. + * Then we compare what we computed against the in-core counters. + * + * However, the reality is that summary counters are a tricky beast to check. + * While we /could/ freeze the filesystem and scramble around the AGs counting + * the free blocks, in practice we prefer not do that for a scan because + * freezing is costly. To get around this, we added a per-cpu counter of the + * delalloc reservations so that we can rotor around the AGs relatively + * quickly, and we allow the counts to be slightly off because we're not taking + * any locks while we do this. + * + * So the first thing we do is warm up the buffer cache in the setup routine by + * walking all the AGs to make sure the incore per-AG structure has been + * initialized. The expected value calculation then iterates the incore per-AG + * structures as quickly as it can. We snapshot the percpu counters before and + * after this operation and use the difference in counter values to guess at + * our tolerance for mismatch between expected and actual counter values. + */ + +/* + * Since the expected value computation is lockless but only browses incore + * values, the percpu counters should be fairly close to each other. However, + * we'll allow ourselves to be off by at least this (arbitrary) amount. + */ +#define XCHK_FSCOUNT_MIN_VARIANCE (512) + +/* + * Make sure the per-AG structure has been initialized from the on-disk header + * contents and trust that the incore counters match the ondisk counters. (The + * AGF and AGI scrubbers check them, and a normal xfs_scrub run checks the + * summary counters after checking all AG headers). Do this from the setup + * function so that the inner AG aggregation loop runs as quickly as possible. + * + * This function runs during the setup phase /before/ we start checking any + * metadata. + */ +STATIC int +xchk_fscount_warmup( + struct xfs_scrub *sc) +{ + struct xfs_mount *mp = sc->mp; + struct xfs_buf *agi_bp = NULL; + struct xfs_buf *agf_bp = NULL; + struct xfs_perag *pag = NULL; + xfs_agnumber_t agno; + int error = 0; + + for (agno = 0; agno < mp->m_sb.sb_agcount; agno++) { + pag = xfs_perag_get(mp, agno); + + if (pag->pagi_init && pag->pagf_init) + goto next_loop_perag; + + /* Lock both AG headers. */ + error = xfs_ialloc_read_agi(mp, sc->tp, agno, &agi_bp); + if (error) + break; + error = xfs_alloc_read_agf(mp, sc->tp, agno, 0, &agf_bp); + if (error) + break; + error = -ENOMEM; + if (!agf_bp || !agi_bp) + break; + + /* + * These are supposed to be initialized by the header read + * function. + */ + error = -EFSCORRUPTED; + if (!pag->pagi_init || !pag->pagf_init) + break; + + xfs_buf_relse(agf_bp); + agf_bp = NULL; + xfs_buf_relse(agi_bp); + agi_bp = NULL; +next_loop_perag: + xfs_perag_put(pag); + pag = NULL; + error = 0; + + if (fatal_signal_pending(current)) + break; + } + + if (agf_bp) + xfs_buf_relse(agf_bp); + if (agi_bp) + xfs_buf_relse(agi_bp); + if (pag) + xfs_perag_put(pag); + return error; +} + +int +xchk_setup_fscounters( + struct xfs_scrub *sc, + struct xfs_inode *ip) +{ + struct xchk_fscounters *fsc; + int error; + + sc->buf = kmem_zalloc(sizeof(struct xchk_fscounters), KM_SLEEP); + if (!sc->buf) + return -ENOMEM; + fsc = sc->buf; + + xfs_icount_range(sc->mp, &fsc->icount_min, &fsc->icount_max); + + /* We must get the incore counters set up before we can proceed. */ + error = xchk_fscount_warmup(sc); + if (error) + return error; + + /* + * Pause background reclaim while we're scrubbing to reduce the + * likelihood of background perturbations to the counters throwing off + * our calculations. + */ + xchk_stop_reaping(sc); + + return xchk_trans_alloc(sc, 0); +} + +/* + * Calculate what the global in-core counters ought to be from the incore + * per-AG structure. Callers can compare this to the actual in-core counters + * to estimate by how much both in-core and on-disk counters need to be + * adjusted. + */ +STATIC int +xchk_fscount_aggregate_agcounts( + struct xfs_scrub *sc, + struct xchk_fscounters *fsc) +{ + struct xfs_mount *mp = sc->mp; + struct xfs_perag *pag; + uint64_t delayed; + xfs_agnumber_t agno; + int tries = 8; + +retry: + fsc->icount = 0; + fsc->ifree = 0; + fsc->fdblocks = 0; + + for (agno = 0; agno < mp->m_sb.sb_agcount; agno++) { + pag = xfs_perag_get(mp, agno); + + /* This somehow got unset since the warmup? */ + if (!pag->pagi_init || !pag->pagf_init) { + xfs_perag_put(pag); + return -EFSCORRUPTED; + } + + /* Count all the inodes */ + fsc->icount += pag->pagi_count; + fsc->ifree += pag->pagi_freecount; + + /* Add up the free/freelist/bnobt/cntbt blocks */ + fsc->fdblocks += pag->pagf_freeblks; + fsc->fdblocks += pag->pagf_flcount; + fsc->fdblocks += pag->pagf_btreeblks; + + /* + * Per-AG reservations are taken out of the incore counters, + * so they must be left out of the free blocks computation. + */ + fsc->fdblocks -= pag->pag_meta_resv.ar_reserved; + fsc->fdblocks -= pag->pag_rmapbt_resv.ar_orig_reserved; + + xfs_perag_put(pag); + + if (fatal_signal_pending(current)) + break; + } + + /* + * The global incore space reservation is taken from the incore + * counters, so leave that out of the computation. + */ + fsc->fdblocks -= mp->m_resblks_avail; + + /* + * Delayed allocation reservations are taken out of the incore counters + * but not recorded on disk, so leave them and their indlen blocks out + * of the computation. + */ + delayed = percpu_counter_sum(&mp->m_delalloc_blks); + fsc->fdblocks -= delayed; + + trace_xchk_fscounters_calc(mp, fsc->icount, fsc->ifree, fsc->fdblocks, + delayed); + + + /* Bail out if the values we compute are totally nonsense. */ + if (fsc->icount < fsc->icount_min || fsc->icount > fsc->icount_max || + fsc->fdblocks > mp->m_sb.sb_dblocks || + fsc->ifree > fsc->icount_max) + return -EFSCORRUPTED; + + /* + * If ifree > icount then we probably had some perturbation in the + * counters while we were calculating things. We'll try a few times + * to maintain ifree <= icount before giving up. + */ + if (fsc->ifree > fsc->icount) { + if (tries--) + goto retry; + xchk_set_incomplete(sc); + return 0; + } + + return 0; +} + +/* + * Is the @counter reasonably close to the @expected value? + * + * We neither locked nor froze anything in the filesystem while aggregating the + * per-AG data to compute the @expected value, which means that the counter + * could have changed. We know the @old_value of the summation of the counter + * before the aggregation, and we re-sum the counter now. If the expected + * value falls between the two summations, we're ok. + * + * Otherwise, we /might/ have a problem. If the change in the summations is + * more than we want to tolerate, the filesystem is probably busy and we should + * just send back INCOMPLETE and see if userspace will try again. + */ +static inline bool +xchk_fscount_within_range( + struct xfs_scrub *sc, + const int64_t old_value, + struct percpu_counter *counter, + uint64_t expected) +{ + int64_t min_value, max_value; + int64_t curr_value = percpu_counter_sum(counter); + + trace_xchk_fscounters_within_range(sc->mp, expected, curr_value, + old_value); + + /* Negative values are always wrong. */ + if (curr_value < 0) + return false; + + /* Exact matches are always ok. */ + if (curr_value == expected) + return true; + + min_value = min(old_value, curr_value); + max_value = max(old_value, curr_value); + + /* Within the before-and-after range is ok. */ + if (expected >= min_value && expected <= max_value) + return true; + + /* + * If the difference between the two summations is too large, the fs + * might just be busy and so we'll mark the scrub incomplete. Return + * true here so that we don't mark the counter corrupt. + * + * XXX: In the future when userspace can grant scrub permission to + * quiesce the filesystem to solve the outsized variance problem, this + * check should be moved up and the return code changed to signal to + * userspace that we need quiesce permission. + */ + if (max_value - min_value >= XCHK_FSCOUNT_MIN_VARIANCE) { + xchk_set_incomplete(sc); + return true; + } + + return false; +} + +/* Check the superblock counters. */ +int +xchk_fscounters( + struct xfs_scrub *sc) +{ + struct xfs_mount *mp = sc->mp; + struct xchk_fscounters *fsc = sc->buf; + int64_t icount, ifree, fdblocks; + int error; + + /* Snapshot the percpu counters. */ + icount = percpu_counter_sum(&mp->m_icount); + ifree = percpu_counter_sum(&mp->m_ifree); + fdblocks = percpu_counter_sum(&mp->m_fdblocks); + + /* No negative values, please! */ + if (icount < 0 || ifree < 0 || fdblocks < 0) + xchk_set_corrupt(sc); + + /* See if icount is obviously wrong. */ + if (icount < fsc->icount_min || icount > fsc->icount_max) + xchk_set_corrupt(sc); + + /* See if fdblocks is obviously wrong. */ + if (fdblocks > mp->m_sb.sb_dblocks) + xchk_set_corrupt(sc); + + /* + * If ifree exceeds icount by more than the minimum variance then + * something's probably wrong with the counters. + */ + if (ifree > icount && ifree - icount > XCHK_FSCOUNT_MIN_VARIANCE) + xchk_set_corrupt(sc); + + /* Walk the incore AG headers to calculate the expected counters. */ + error = xchk_fscount_aggregate_agcounts(sc, fsc); + if (!xchk_process_error(sc, 0, XFS_SB_BLOCK(mp), &error)) + return error; + if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_INCOMPLETE) + return 0; + + /* Compare the in-core counters with whatever we counted. */ + if (!xchk_fscount_within_range(sc, icount, &mp->m_icount, fsc->icount)) + xchk_set_corrupt(sc); + + if (!xchk_fscount_within_range(sc, ifree, &mp->m_ifree, fsc->ifree)) + xchk_set_corrupt(sc); + + if (!xchk_fscount_within_range(sc, fdblocks, &mp->m_fdblocks, + fsc->fdblocks)) + xchk_set_corrupt(sc); + + return 0; +} diff --git a/fs/xfs/scrub/health.c b/fs/xfs/scrub/health.c index 16b536aa125e..23cf8e2f25db 100644 --- a/fs/xfs/scrub/health.c +++ b/fs/xfs/scrub/health.c @@ -109,6 +109,7 @@ static const struct xchk_health_map type_to_health_flag[XFS_SCRUB_TYPE_NR] = { [XFS_SCRUB_TYPE_UQUOTA] = { XHG_FS, XFS_SICK_FS_UQUOTA }, [XFS_SCRUB_TYPE_GQUOTA] = { XHG_FS, XFS_SICK_FS_GQUOTA }, [XFS_SCRUB_TYPE_PQUOTA] = { XHG_FS, XFS_SICK_FS_PQUOTA }, + [XFS_SCRUB_TYPE_FSCOUNTERS] = { XHG_FS, XFS_SICK_FS_COUNTERS }, }; /* Return the health status mask for this scrub type. */ diff --git a/fs/xfs/scrub/scrub.c b/fs/xfs/scrub/scrub.c index ce13c1c366db..f630389ee176 100644 --- a/fs/xfs/scrub/scrub.c +++ b/fs/xfs/scrub/scrub.c @@ -352,6 +352,12 @@ static const struct xchk_meta_ops meta_scrub_ops[] = { .scrub = xchk_quota, .repair = xrep_notsupported, }, + [XFS_SCRUB_TYPE_FSCOUNTERS] = { /* fs summary counters */ + .type = ST_FS, + .setup = xchk_setup_fscounters, + .scrub = xchk_fscounters, + .repair = xrep_notsupported, + }, }; /* 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 01986ed364db..ad1ceb44a628 100644 --- a/fs/xfs/scrub/scrub.h +++ b/fs/xfs/scrub/scrub.h @@ -127,6 +127,7 @@ xchk_quota(struct xfs_scrub *sc) return -ENOENT; } #endif +int xchk_fscounters(struct xfs_scrub *sc); /* cross-referencing helpers */ void xchk_xref_is_used_space(struct xfs_scrub *sc, xfs_agblock_t agbno, @@ -152,4 +153,12 @@ void xchk_xref_is_used_rt_space(struct xfs_scrub *sc, xfs_rtblock_t rtbno, # define xchk_xref_is_used_rt_space(sc, rtbno, len) do { } while (0) #endif +struct xchk_fscounters { + uint64_t icount; + uint64_t ifree; + uint64_t fdblocks; + unsigned long long icount_min; + unsigned long long icount_max; +}; + #endif /* __XFS_SCRUB_SCRUB_H__ */ diff --git a/fs/xfs/scrub/trace.h b/fs/xfs/scrub/trace.h index 3c83e8b3b39c..3362bae28b46 100644 --- a/fs/xfs/scrub/trace.h +++ b/fs/xfs/scrub/trace.h @@ -50,6 +50,7 @@ TRACE_DEFINE_ENUM(XFS_SCRUB_TYPE_RTSUM); TRACE_DEFINE_ENUM(XFS_SCRUB_TYPE_UQUOTA); TRACE_DEFINE_ENUM(XFS_SCRUB_TYPE_GQUOTA); TRACE_DEFINE_ENUM(XFS_SCRUB_TYPE_PQUOTA); +TRACE_DEFINE_ENUM(XFS_SCRUB_TYPE_FSCOUNTERS); #define XFS_SCRUB_TYPE_STRINGS \ { XFS_SCRUB_TYPE_PROBE, "probe" }, \ @@ -75,7 +76,8 @@ TRACE_DEFINE_ENUM(XFS_SCRUB_TYPE_PQUOTA); { XFS_SCRUB_TYPE_RTSUM, "rtsummary" }, \ { XFS_SCRUB_TYPE_UQUOTA, "usrquota" }, \ { XFS_SCRUB_TYPE_GQUOTA, "grpquota" }, \ - { XFS_SCRUB_TYPE_PQUOTA, "prjquota" } + { XFS_SCRUB_TYPE_PQUOTA, "prjquota" }, \ + { XFS_SCRUB_TYPE_FSCOUNTERS, "fscounters" } DECLARE_EVENT_CLASS(xchk_class, TP_PROTO(struct xfs_inode *ip, struct xfs_scrub_metadata *sm, @@ -223,6 +225,7 @@ DEFINE_EVENT(xchk_block_error_class, name, \ void *ret_ip), \ TP_ARGS(sc, daddr, ret_ip)) +DEFINE_SCRUB_BLOCK_ERROR_EVENT(xchk_fs_error); DEFINE_SCRUB_BLOCK_ERROR_EVENT(xchk_block_error); DEFINE_SCRUB_BLOCK_ERROR_EVENT(xchk_block_preen); @@ -590,6 +593,64 @@ TRACE_EVENT(xchk_iallocbt_check_cluster, __entry->cluster_ino) ) +TRACE_EVENT(xchk_fscounters_calc, + TP_PROTO(struct xfs_mount *mp, uint64_t icount, uint64_t ifree, + uint64_t fdblocks, uint64_t delalloc), + TP_ARGS(mp, icount, ifree, fdblocks, delalloc), + TP_STRUCT__entry( + __field(dev_t, dev) + __field(int64_t, icount_sb) + __field(uint64_t, icount_calculated) + __field(int64_t, ifree_sb) + __field(uint64_t, ifree_calculated) + __field(int64_t, fdblocks_sb) + __field(uint64_t, fdblocks_calculated) + __field(uint64_t, delalloc) + ), + TP_fast_assign( + __entry->dev = mp->m_super->s_dev; + __entry->icount_sb = mp->m_sb.sb_icount; + __entry->icount_calculated = icount; + __entry->ifree_sb = mp->m_sb.sb_ifree; + __entry->ifree_calculated = ifree; + __entry->fdblocks_sb = mp->m_sb.sb_fdblocks; + __entry->fdblocks_calculated = fdblocks; + __entry->delalloc = delalloc; + ), + TP_printk("dev %d:%d icount %lld:%llu ifree %lld::%llu fdblocks %lld::%llu delalloc %llu", + MAJOR(__entry->dev), MINOR(__entry->dev), + __entry->icount_sb, + __entry->icount_calculated, + __entry->ifree_sb, + __entry->ifree_calculated, + __entry->fdblocks_sb, + __entry->fdblocks_calculated, + __entry->delalloc) +) + +TRACE_EVENT(xchk_fscounters_within_range, + TP_PROTO(struct xfs_mount *mp, uint64_t expected, int64_t curr_value, + int64_t old_value), + TP_ARGS(mp, expected, curr_value, old_value), + TP_STRUCT__entry( + __field(dev_t, dev) + __field(uint64_t, expected) + __field(int64_t, curr_value) + __field(int64_t, old_value) + ), + TP_fast_assign( + __entry->dev = mp->m_super->s_dev; + __entry->expected = expected; + __entry->curr_value = curr_value; + __entry->old_value = old_value; + ), + TP_printk("dev %d:%d expected %llu curr_value %lld old_value %lld", + MAJOR(__entry->dev), MINOR(__entry->dev), + __entry->expected, + __entry->curr_value, + __entry->old_value) +) + /* repair tracepoints */ #if IS_ENABLED(CONFIG_XFS_ONLINE_REPAIR) |