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path: root/fs/xfs/libxfs/xfs_alloc.c
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Diffstat (limited to 'fs/xfs/libxfs/xfs_alloc.c')
-rw-r--r--fs/xfs/libxfs/xfs_alloc.c139
1 files changed, 121 insertions, 18 deletions
diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c
index c02781a4c091..39387bdd225d 100644
--- a/fs/xfs/libxfs/xfs_alloc.c
+++ b/fs/xfs/libxfs/xfs_alloc.c
@@ -53,6 +53,23 @@ STATIC int xfs_alloc_ag_vextent_size(xfs_alloc_arg_t *);
STATIC int xfs_alloc_ag_vextent_small(xfs_alloc_arg_t *,
xfs_btree_cur_t *, xfs_agblock_t *, xfs_extlen_t *, int *);
+/*
+ * Size of the AGFL. For CRC-enabled filesystes we steal a couple of slots in
+ * the beginning of the block for a proper header with the location information
+ * and CRC.
+ */
+unsigned int
+xfs_agfl_size(
+ struct xfs_mount *mp)
+{
+ unsigned int size = mp->m_sb.sb_sectsize;
+
+ if (xfs_sb_version_hascrc(&mp->m_sb))
+ size -= sizeof(struct xfs_agfl);
+
+ return size / sizeof(xfs_agblock_t);
+}
+
unsigned int
xfs_refc_block(
struct xfs_mount *mp)
@@ -550,7 +567,7 @@ xfs_agfl_verify(
if (bp->b_pag && be32_to_cpu(agfl->agfl_seqno) != bp->b_pag->pag_agno)
return __this_address;
- for (i = 0; i < XFS_AGFL_SIZE(mp); i++) {
+ for (i = 0; i < xfs_agfl_size(mp); i++) {
if (be32_to_cpu(agfl->agfl_bno[i]) != NULLAGBLOCK &&
be32_to_cpu(agfl->agfl_bno[i]) >= mp->m_sb.sb_agblocks)
return __this_address;
@@ -1564,7 +1581,6 @@ xfs_alloc_ag_vextent_small(
int *stat) /* status: 0-freelist, 1-normal/none */
{
struct xfs_owner_info oinfo;
- struct xfs_perag *pag;
int error;
xfs_agblock_t fbno;
xfs_extlen_t flen;
@@ -1616,18 +1632,13 @@ xfs_alloc_ag_vextent_small(
/*
* If we're feeding an AGFL block to something that
* doesn't live in the free space, we need to clear
- * out the OWN_AG rmap and add the block back to
- * the AGFL per-AG reservation.
+ * out the OWN_AG rmap.
*/
xfs_rmap_ag_owner(&oinfo, XFS_RMAP_OWN_AG);
error = xfs_rmap_free(args->tp, args->agbp, args->agno,
fbno, 1, &oinfo);
if (error)
goto error0;
- pag = xfs_perag_get(args->mp, args->agno);
- xfs_ag_resv_free_extent(pag, XFS_AG_RESV_AGFL,
- args->tp, 1);
- xfs_perag_put(pag);
*stat = 0;
return 0;
@@ -1911,14 +1922,12 @@ xfs_free_ag_extent(
XFS_STATS_INC(mp, xs_freex);
XFS_STATS_ADD(mp, xs_freeb, len);
- trace_xfs_free_extent(mp, agno, bno, len, type == XFS_AG_RESV_AGFL,
- haveleft, haveright);
+ trace_xfs_free_extent(mp, agno, bno, len, type, haveleft, haveright);
return 0;
error0:
- trace_xfs_free_extent(mp, agno, bno, len, type == XFS_AG_RESV_AGFL,
- -1, -1);
+ trace_xfs_free_extent(mp, agno, bno, len, type, -1, -1);
if (bno_cur)
xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
if (cnt_cur)
@@ -2054,6 +2063,93 @@ xfs_alloc_space_available(
}
/*
+ * Check the agfl fields of the agf for inconsistency or corruption. The purpose
+ * is to detect an agfl header padding mismatch between current and early v5
+ * kernels. This problem manifests as a 1-slot size difference between the
+ * on-disk flcount and the active [first, last] range of a wrapped agfl. This
+ * may also catch variants of agfl count corruption unrelated to padding. Either
+ * way, we'll reset the agfl and warn the user.
+ *
+ * Return true if a reset is required before the agfl can be used, false
+ * otherwise.
+ */
+static bool
+xfs_agfl_needs_reset(
+ struct xfs_mount *mp,
+ struct xfs_agf *agf)
+{
+ uint32_t f = be32_to_cpu(agf->agf_flfirst);
+ uint32_t l = be32_to_cpu(agf->agf_fllast);
+ uint32_t c = be32_to_cpu(agf->agf_flcount);
+ int agfl_size = xfs_agfl_size(mp);
+ int active;
+
+ /* no agfl header on v4 supers */
+ if (!xfs_sb_version_hascrc(&mp->m_sb))
+ return false;
+
+ /*
+ * The agf read verifier catches severe corruption of these fields.
+ * Repeat some sanity checks to cover a packed -> unpacked mismatch if
+ * the verifier allows it.
+ */
+ if (f >= agfl_size || l >= agfl_size)
+ return true;
+ if (c > agfl_size)
+ return true;
+
+ /*
+ * Check consistency between the on-disk count and the active range. An
+ * agfl padding mismatch manifests as an inconsistent flcount.
+ */
+ if (c && l >= f)
+ active = l - f + 1;
+ else if (c)
+ active = agfl_size - f + l + 1;
+ else
+ active = 0;
+
+ return active != c;
+}
+
+/*
+ * Reset the agfl to an empty state. Ignore/drop any existing blocks since the
+ * agfl content cannot be trusted. Warn the user that a repair is required to
+ * recover leaked blocks.
+ *
+ * The purpose of this mechanism is to handle filesystems affected by the agfl
+ * header padding mismatch problem. A reset keeps the filesystem online with a
+ * relatively minor free space accounting inconsistency rather than suffer the
+ * inevitable crash from use of an invalid agfl block.
+ */
+static void
+xfs_agfl_reset(
+ struct xfs_trans *tp,
+ struct xfs_buf *agbp,
+ struct xfs_perag *pag)
+{
+ struct xfs_mount *mp = tp->t_mountp;
+ struct xfs_agf *agf = XFS_BUF_TO_AGF(agbp);
+
+ ASSERT(pag->pagf_agflreset);
+ trace_xfs_agfl_reset(mp, agf, 0, _RET_IP_);
+
+ xfs_warn(mp,
+ "WARNING: Reset corrupted AGFL on AG %u. %d blocks leaked. "
+ "Please unmount and run xfs_repair.",
+ pag->pag_agno, pag->pagf_flcount);
+
+ agf->agf_flfirst = 0;
+ agf->agf_fllast = cpu_to_be32(xfs_agfl_size(mp) - 1);
+ agf->agf_flcount = 0;
+ xfs_alloc_log_agf(tp, agbp, XFS_AGF_FLFIRST | XFS_AGF_FLLAST |
+ XFS_AGF_FLCOUNT);
+
+ pag->pagf_flcount = 0;
+ pag->pagf_agflreset = false;
+}
+
+/*
* Decide whether to use this allocation group for this allocation.
* If so, fix up the btree freelist's size.
*/
@@ -2114,6 +2210,10 @@ xfs_alloc_fix_freelist(
}
}
+ /* reset a padding mismatched agfl before final free space check */
+ if (pag->pagf_agflreset)
+ xfs_agfl_reset(tp, agbp, pag);
+
/* If there isn't enough total space or single-extent, reject it. */
need = xfs_alloc_min_freelist(mp, pag);
if (!xfs_alloc_space_available(args, need, flags))
@@ -2266,10 +2366,11 @@ xfs_alloc_get_freelist(
bno = be32_to_cpu(agfl_bno[be32_to_cpu(agf->agf_flfirst)]);
be32_add_cpu(&agf->agf_flfirst, 1);
xfs_trans_brelse(tp, agflbp);
- if (be32_to_cpu(agf->agf_flfirst) == XFS_AGFL_SIZE(mp))
+ if (be32_to_cpu(agf->agf_flfirst) == xfs_agfl_size(mp))
agf->agf_flfirst = 0;
pag = xfs_perag_get(mp, be32_to_cpu(agf->agf_seqno));
+ ASSERT(!pag->pagf_agflreset);
be32_add_cpu(&agf->agf_flcount, -1);
xfs_trans_agflist_delta(tp, -1);
pag->pagf_flcount--;
@@ -2377,10 +2478,11 @@ xfs_alloc_put_freelist(
be32_to_cpu(agf->agf_seqno), &agflbp)))
return error;
be32_add_cpu(&agf->agf_fllast, 1);
- if (be32_to_cpu(agf->agf_fllast) == XFS_AGFL_SIZE(mp))
+ if (be32_to_cpu(agf->agf_fllast) == xfs_agfl_size(mp))
agf->agf_fllast = 0;
pag = xfs_perag_get(mp, be32_to_cpu(agf->agf_seqno));
+ ASSERT(!pag->pagf_agflreset);
be32_add_cpu(&agf->agf_flcount, 1);
xfs_trans_agflist_delta(tp, 1);
pag->pagf_flcount++;
@@ -2395,7 +2497,7 @@ xfs_alloc_put_freelist(
xfs_alloc_log_agf(tp, agbp, logflags);
- ASSERT(be32_to_cpu(agf->agf_flcount) <= XFS_AGFL_SIZE(mp));
+ ASSERT(be32_to_cpu(agf->agf_flcount) <= xfs_agfl_size(mp));
agfl_bno = XFS_BUF_TO_AGFL_BNO(mp, agflbp);
blockp = &agfl_bno[be32_to_cpu(agf->agf_fllast)];
@@ -2428,9 +2530,9 @@ xfs_agf_verify(
if (!(agf->agf_magicnum == cpu_to_be32(XFS_AGF_MAGIC) &&
XFS_AGF_GOOD_VERSION(be32_to_cpu(agf->agf_versionnum)) &&
be32_to_cpu(agf->agf_freeblks) <= be32_to_cpu(agf->agf_length) &&
- be32_to_cpu(agf->agf_flfirst) < XFS_AGFL_SIZE(mp) &&
- be32_to_cpu(agf->agf_fllast) < XFS_AGFL_SIZE(mp) &&
- be32_to_cpu(agf->agf_flcount) <= XFS_AGFL_SIZE(mp)))
+ be32_to_cpu(agf->agf_flfirst) < xfs_agfl_size(mp) &&
+ be32_to_cpu(agf->agf_fllast) < xfs_agfl_size(mp) &&
+ be32_to_cpu(agf->agf_flcount) <= xfs_agfl_size(mp)))
return __this_address;
if (be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNO]) < 1 ||
@@ -2588,6 +2690,7 @@ xfs_alloc_read_agf(
pag->pagb_count = 0;
pag->pagb_tree = RB_ROOT;
pag->pagf_init = 1;
+ pag->pagf_agflreset = xfs_agfl_needs_reset(mp, agf);
}
#ifdef DEBUG
else if (!XFS_FORCED_SHUTDOWN(mp)) {
generated by cgit v1.2.3-70-g09d2 (git 2.48.1) at 2025-02-15 05:07:46 +0000