From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops There's some internal state that ftrace_ops needs to have set, but since it can be declared outside of the ftrace.c code, it calls ftrace_ops_init() on the ops in every global function. The issue is that if two tasks call it on the same ops at the same time it is possible to have the initialization of one corrupt the initialization of the other call. Create a ops_mutex to use to synchronize every initialization of the ftrace_ops. The mutex is taken within checking the ftrace_ops flag that states it was initializied but the flag is checked again after the mutex has been taken. Checking first outside the mutex allows it to shortcut having to take the mutex. But then the check needs to be done again after the mute is taken in case of races. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock") Reported-by: sashiko-bot@kernel.org Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/ Signed-off-by: Steven Rostedt --- fs/xfs/scrub/rtbitmap.c | 299 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 299 insertions(+) create mode 100644 fs/xfs/scrub/rtbitmap.c (limited to 'fs/xfs/scrub/rtbitmap.c') diff --git a/fs/xfs/scrub/rtbitmap.c b/fs/xfs/scrub/rtbitmap.c new file mode 100644 index 000000000..52c24d3d4 --- /dev/null +++ b/fs/xfs/scrub/rtbitmap.c @@ -0,0 +1,299 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2017-2023 Oracle. All Rights Reserved. + * Author: Darrick J. Wong + */ +#include "xfs_platform.h" +#include "xfs_fs.h" +#include "xfs_shared.h" +#include "xfs_format.h" +#include "xfs_trans_resv.h" +#include "xfs_mount.h" +#include "xfs_btree.h" +#include "xfs_log_format.h" +#include "xfs_trans.h" +#include "xfs_rtbitmap.h" +#include "xfs_inode.h" +#include "xfs_bmap.h" +#include "xfs_bit.h" +#include "xfs_rtgroup.h" +#include "xfs_sb.h" +#include "xfs_rmap.h" +#include "xfs_rtrmap_btree.h" +#include "xfs_exchmaps.h" +#include "xfs_zone_alloc.h" +#include "scrub/scrub.h" +#include "scrub/common.h" +#include "scrub/repair.h" +#include "scrub/tempexch.h" +#include "scrub/rtbitmap.h" +#include "scrub/btree.h" + +/* Set us up with the realtime metadata locked. */ +int +xchk_setup_rtbitmap( + struct xfs_scrub *sc) +{ + struct xfs_mount *mp = sc->mp; + struct xchk_rtbitmap *rtb; + int error; + + if (xchk_need_intent_drain(sc)) + xchk_fsgates_enable(sc, XCHK_FSGATES_DRAIN); + + rtb = kzalloc_flex(*rtb, words, xchk_rtbitmap_wordcnt(sc), + XCHK_GFP_FLAGS); + if (!rtb) + return -ENOMEM; + sc->buf = rtb; + rtb->sc = sc; + + error = xchk_rtgroup_init(sc, sc->sm->sm_agno, &sc->sr); + if (error) + return error; + + if (xchk_could_repair(sc)) { + error = xrep_setup_rtbitmap(sc, rtb); + if (error) + return error; + } + + error = xchk_trans_alloc(sc, rtb->resblks); + if (error) + return error; + + error = xchk_install_live_inode(sc, rtg_bitmap(sc->sr.rtg)); + if (error) + return error; + + error = xchk_ino_dqattach(sc); + if (error) + return error; + + error = xchk_rtgroup_lock(sc, &sc->sr, XCHK_RTGLOCK_ALL); + if (error) + return error; + + /* + * Now that we've locked the rtbitmap, we can't race with growfsrt + * trying to expand the bitmap or change the size of the rt volume. + * Hence it is safe to compute and check the geometry values. + */ + if (mp->m_sb.sb_rblocks) { + rtb->rextents = xfs_blen_to_rtbxlen(mp, mp->m_sb.sb_rblocks); + rtb->rextslog = xfs_compute_rextslog(rtb->rextents); + rtb->rbmblocks = xfs_rtbitmap_blockcount(mp); + } + + return 0; +} + +/* Per-rtgroup bitmap contents. */ + +/* Cross-reference rtbitmap entries with other metadata. */ +STATIC void +xchk_rtbitmap_xref( + struct xchk_rtbitmap *rtb, + xfs_rtblock_t startblock, + xfs_rtblock_t blockcount) +{ + struct xfs_scrub *sc = rtb->sc; + xfs_rgblock_t rgbno = xfs_rtb_to_rgbno(sc->mp, startblock); + + if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT) + return; + if (!sc->sr.rmap_cur) + return; + + xchk_xref_has_no_rt_owner(sc, rgbno, blockcount); + xchk_xref_is_not_rt_shared(sc, rgbno, blockcount); + xchk_xref_is_not_rt_cow_staging(sc, rgbno, blockcount); + + if (rtb->next_free_rgbno < rgbno) + xchk_xref_has_rt_owner(sc, rtb->next_free_rgbno, + rgbno - rtb->next_free_rgbno); + rtb->next_free_rgbno = rgbno + blockcount; +} + +/* Scrub a free extent record from the realtime bitmap. */ +STATIC int +xchk_rtbitmap_rec( + struct xfs_rtgroup *rtg, + struct xfs_trans *tp, + const struct xfs_rtalloc_rec *rec, + void *priv) +{ + struct xchk_rtbitmap *rtb = priv; + struct xfs_scrub *sc = rtb->sc; + xfs_rtblock_t startblock; + xfs_filblks_t blockcount; + + startblock = xfs_rtx_to_rtb(rtg, rec->ar_startext); + blockcount = xfs_rtxlen_to_extlen(rtg_mount(rtg), rec->ar_extcount); + + if (!xfs_verify_rtbext(rtg_mount(rtg), startblock, blockcount)) + xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0); + + xchk_rtbitmap_xref(rtb, startblock, blockcount); + + if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT) + return -ECANCELED; + + return 0; +} + +/* Make sure the entire rtbitmap file is mapped with written extents. */ +STATIC int +xchk_rtbitmap_check_extents( + struct xfs_scrub *sc) +{ + struct xfs_bmbt_irec map; + struct xfs_iext_cursor icur; + struct xfs_mount *mp = sc->mp; + struct xfs_inode *ip = sc->ip; + xfs_fileoff_t off = 0; + xfs_fileoff_t endoff; + int error = 0; + + /* Mappings may not cross or lie beyond EOF. */ + endoff = XFS_B_TO_FSB(mp, ip->i_disk_size); + if (xfs_iext_lookup_extent(ip, &ip->i_df, endoff, &icur, &map)) { + xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, endoff); + return 0; + } + + while (off < endoff) { + int nmap = 1; + + if (xchk_should_terminate(sc, &error) || + (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)) + break; + + /* Make sure we have a written extent. */ + error = xfs_bmapi_read(ip, off, endoff - off, &map, &nmap, + XFS_DATA_FORK); + if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, off, &error)) + break; + + if (nmap != 1 || !xfs_bmap_is_written_extent(&map)) { + xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, off); + break; + } + + off += map.br_blockcount; + } + + return error; +} + +/* Scrub this group's realtime bitmap. */ +int +xchk_rtbitmap( + struct xfs_scrub *sc) +{ + struct xfs_mount *mp = sc->mp; + struct xfs_rtgroup *rtg = sc->sr.rtg; + struct xfs_inode *rbmip = rtg_bitmap(rtg); + struct xchk_rtbitmap *rtb = sc->buf; + xfs_rgblock_t last_rgbno; + int error; + + /* Is sb_rextents correct? */ + if (mp->m_sb.sb_rextents != rtb->rextents) { + xchk_ip_set_corrupt(sc, rbmip); + return 0; + } + + /* Is sb_rextslog correct? */ + if (mp->m_sb.sb_rextslog != rtb->rextslog) { + xchk_ip_set_corrupt(sc, rbmip); + return 0; + } + + /* + * Is sb_rbmblocks large enough to handle the current rt volume? In no + * case can we exceed 4bn bitmap blocks since the super field is a u32. + */ + if (rtb->rbmblocks > U32_MAX) { + xchk_ip_set_corrupt(sc, rbmip); + return 0; + } + if (mp->m_sb.sb_rbmblocks != rtb->rbmblocks) { + xchk_ip_set_corrupt(sc, rbmip); + return 0; + } + + /* The bitmap file length must be aligned to an fsblock. */ + if (rbmip->i_disk_size & mp->m_blockmask) { + xchk_ip_set_corrupt(sc, rbmip); + return 0; + } + + /* + * Is the bitmap file itself large enough to handle the rt volume? + * growfsrt expands the bitmap file before updating sb_rextents, so the + * file can be larger than sb_rbmblocks. + */ + if (rbmip->i_disk_size < XFS_FSB_TO_B(mp, rtb->rbmblocks)) { + xchk_ip_set_corrupt(sc, rbmip); + return 0; + } + + /* Invoke the fork scrubber. */ + error = xchk_metadata_inode_forks(sc); + if (error || (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)) + return error; + + error = xchk_rtbitmap_check_extents(sc); + if (error || (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)) + return error; + + rtb->next_free_rgbno = 0; + error = xfs_rtalloc_query_all(rtg, sc->tp, xchk_rtbitmap_rec, rtb); + if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, 0, &error)) + return error; + + /* + * Check that the are rmappings for all rt extents between the end of + * the last free extent we saw and the last possible extent in the rt + * group. + */ + last_rgbno = rtg->rtg_extents * mp->m_sb.sb_rextsize; + if (rtb->next_free_rgbno < last_rgbno) + xchk_xref_has_rt_owner(sc, rtb->next_free_rgbno, + last_rgbno - rtb->next_free_rgbno); + return 0; +} + +/* xref check that the extent is not free in the rtbitmap */ +void +xchk_xref_is_used_rt_space( + struct xfs_scrub *sc, + xfs_rtblock_t rtbno, + xfs_extlen_t len) +{ + struct xfs_rtgroup *rtg = sc->sr.rtg; + xfs_rtxnum_t startext; + xfs_rtxnum_t endext; + bool is_free; + int error; + + if (xchk_skip_xref(sc->sm)) + return; + + if (xfs_has_zoned(sc->mp)) { + if (!xfs_zone_rgbno_is_valid(rtg, + xfs_rtb_to_rgbno(sc->mp, rtbno) + len - 1)) + xchk_ip_xref_set_corrupt(sc, rtg_rmap(rtg)); + return; + } + + startext = xfs_rtb_to_rtx(sc->mp, rtbno); + endext = xfs_rtb_to_rtx(sc->mp, rtbno + len - 1); + error = xfs_rtalloc_extent_is_free(rtg, sc->tp, startext, + endext - startext + 1, &is_free); + if (!xchk_should_check_xref(sc, &error, NULL)) + return; + if (is_free) + xchk_ip_xref_set_corrupt(sc, rtg_bitmap(rtg)); +} -- cgit v1.3.1