From 3afb00d3f86d3d924f88b56fa8285d4e9db85852 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Wed, 7 Aug 2024 15:17:52 +0200 Subject: Merging upstream version 6.10.3. Signed-off-by: Daniel Baumann --- fs/xfs/scrub/reap.c | 445 +++++++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 423 insertions(+), 22 deletions(-) (limited to 'fs/xfs/scrub/reap.c') diff --git a/fs/xfs/scrub/reap.c b/fs/xfs/scrub/reap.c index 0252a3b5b6..be283153c2 100644 --- a/fs/xfs/scrub/reap.c +++ b/fs/xfs/scrub/reap.c @@ -211,6 +211,48 @@ static inline void xreap_defer_finish_reset(struct xreap_state *rs) rs->force_roll = false; } +/* + * Compute the maximum length of a buffer cache scan (in units of sectors), + * given a quantity of fs blocks. + */ +xfs_daddr_t +xrep_bufscan_max_sectors( + struct xfs_mount *mp, + xfs_extlen_t fsblocks) +{ + int max_fsbs; + + /* Remote xattr values are the largest buffers that we support. */ + max_fsbs = xfs_attr3_max_rmt_blocks(mp); + + return XFS_FSB_TO_BB(mp, min_t(xfs_extlen_t, fsblocks, max_fsbs)); +} + +/* + * Return an incore buffer from a sector scan, or NULL if there are no buffers + * left to return. + */ +struct xfs_buf * +xrep_bufscan_advance( + struct xfs_mount *mp, + struct xrep_bufscan *scan) +{ + scan->__sector_count += scan->daddr_step; + while (scan->__sector_count <= scan->max_sectors) { + struct xfs_buf *bp = NULL; + int error; + + error = xfs_buf_incore(mp->m_ddev_targp, scan->daddr, + scan->__sector_count, XBF_LIVESCAN, &bp); + if (!error) + return bp; + + scan->__sector_count += scan->daddr_step; + } + + return NULL; +} + /* Try to invalidate the incore buffers for an extent that we're freeing. */ STATIC void xreap_agextent_binval( @@ -241,28 +283,15 @@ xreap_agextent_binval( * of any plausible size. */ while (bno < agbno_next) { - xfs_agblock_t fsbcount; - xfs_agblock_t max_fsbs; - - /* - * Max buffer size is the max remote xattr buffer size, which - * is one fs block larger than 64k. - */ - max_fsbs = min_t(xfs_agblock_t, agbno_next - bno, - xfs_attr3_rmt_blocks(mp, XFS_XATTR_SIZE_MAX)); - - for (fsbcount = 1; fsbcount <= max_fsbs; fsbcount++) { - struct xfs_buf *bp = NULL; - xfs_daddr_t daddr; - int error; - - daddr = XFS_AGB_TO_DADDR(mp, agno, bno); - error = xfs_buf_incore(mp->m_ddev_targp, daddr, - XFS_FSB_TO_BB(mp, fsbcount), - XBF_LIVESCAN, &bp); - if (error) - continue; - + struct xrep_bufscan scan = { + .daddr = XFS_AGB_TO_DADDR(mp, agno, bno), + .max_sectors = xrep_bufscan_max_sectors(mp, + agbno_next - bno), + .daddr_step = XFS_FSB_TO_BB(mp, 1), + }; + struct xfs_buf *bp; + + while ((bp = xrep_bufscan_advance(mp, &scan)) != NULL) { xfs_trans_bjoin(sc->tp, bp); xfs_trans_binval(sc->tp, bp); rs->invalidated++; @@ -646,3 +675,375 @@ xrep_reap_fsblocks( return 0; } + +/* + * Metadata files are not supposed to share blocks with anything else. + * If blocks are shared, we remove the reverse mapping (thus reducing the + * crosslink factor); if blocks are not shared, we also need to free them. + * + * This first step determines the longest subset of the passed-in imap + * (starting at its beginning) that is either crosslinked or not crosslinked. + * The blockcount will be adjust down as needed. + */ +STATIC int +xreap_bmapi_select( + struct xfs_scrub *sc, + struct xfs_inode *ip, + int whichfork, + struct xfs_bmbt_irec *imap, + bool *crosslinked) +{ + struct xfs_owner_info oinfo; + struct xfs_btree_cur *cur; + xfs_filblks_t len = 1; + xfs_agblock_t bno; + xfs_agblock_t agbno; + xfs_agblock_t agbno_next; + int error; + + agbno = XFS_FSB_TO_AGBNO(sc->mp, imap->br_startblock); + agbno_next = agbno + imap->br_blockcount; + + cur = xfs_rmapbt_init_cursor(sc->mp, sc->tp, sc->sa.agf_bp, + sc->sa.pag); + + xfs_rmap_ino_owner(&oinfo, ip->i_ino, whichfork, imap->br_startoff); + error = xfs_rmap_has_other_keys(cur, agbno, 1, &oinfo, crosslinked); + if (error) + goto out_cur; + + bno = agbno + 1; + while (bno < agbno_next) { + bool also_crosslinked; + + oinfo.oi_offset++; + error = xfs_rmap_has_other_keys(cur, bno, 1, &oinfo, + &also_crosslinked); + if (error) + goto out_cur; + + if (also_crosslinked != *crosslinked) + break; + + len++; + bno++; + } + + imap->br_blockcount = len; + trace_xreap_bmapi_select(sc->sa.pag, agbno, len, *crosslinked); +out_cur: + xfs_btree_del_cursor(cur, error); + return error; +} + +/* + * Decide if this buffer can be joined to a transaction. This is true for most + * buffers, but there are two cases that we want to catch: large remote xattr + * value buffers are not logged and can overflow the buffer log item dirty + * bitmap size; and oversized cached buffers if things have really gone + * haywire. + */ +static inline bool +xreap_buf_loggable( + const struct xfs_buf *bp) +{ + int i; + + for (i = 0; i < bp->b_map_count; i++) { + int chunks; + int map_size; + + chunks = DIV_ROUND_UP(BBTOB(bp->b_maps[i].bm_len), + XFS_BLF_CHUNK); + map_size = DIV_ROUND_UP(chunks, NBWORD); + if (map_size > XFS_BLF_DATAMAP_SIZE) + return false; + } + + return true; +} + +/* + * Invalidate any buffers for this file mapping. The @imap blockcount may be + * adjusted downward if we need to roll the transaction. + */ +STATIC int +xreap_bmapi_binval( + struct xfs_scrub *sc, + struct xfs_inode *ip, + int whichfork, + struct xfs_bmbt_irec *imap) +{ + struct xfs_mount *mp = sc->mp; + struct xfs_perag *pag = sc->sa.pag; + int bmap_flags = xfs_bmapi_aflag(whichfork); + xfs_fileoff_t off; + xfs_fileoff_t max_off; + xfs_extlen_t scan_blocks; + xfs_agnumber_t agno = sc->sa.pag->pag_agno; + xfs_agblock_t bno; + xfs_agblock_t agbno; + xfs_agblock_t agbno_next; + unsigned int invalidated = 0; + int error; + + /* + * Avoid invalidating AG headers and post-EOFS blocks because we never + * own those. + */ + agbno = bno = XFS_FSB_TO_AGBNO(sc->mp, imap->br_startblock); + agbno_next = agbno + imap->br_blockcount; + if (!xfs_verify_agbno(pag, agbno) || + !xfs_verify_agbno(pag, agbno_next - 1)) + return 0; + + /* + * Buffers for file blocks can span multiple contiguous mappings. This + * means that for each block in the mapping, there could exist an + * xfs_buf indexed by that block with any length up to the maximum + * buffer size (remote xattr values) or to the next hole in the fork. + * To set up our binval scan, first we need to figure out the location + * of the next hole. + */ + off = imap->br_startoff + imap->br_blockcount; + max_off = off + xfs_attr3_max_rmt_blocks(mp); + while (off < max_off) { + struct xfs_bmbt_irec hmap; + int nhmaps = 1; + + error = xfs_bmapi_read(ip, off, max_off - off, &hmap, + &nhmaps, bmap_flags); + if (error) + return error; + if (nhmaps != 1 || hmap.br_startblock == DELAYSTARTBLOCK) { + ASSERT(0); + return -EFSCORRUPTED; + } + + if (!xfs_bmap_is_real_extent(&hmap)) + break; + + off = hmap.br_startoff + hmap.br_blockcount; + } + scan_blocks = off - imap->br_startoff; + + trace_xreap_bmapi_binval_scan(sc, imap, scan_blocks); + + /* + * If there are incore buffers for these blocks, invalidate them. If + * we can't (try)lock the buffer we assume it's owned by someone else + * and leave it alone. The buffer cache cannot detect aliasing, so + * employ nested loops to detect incore buffers of any plausible size. + */ + while (bno < agbno_next) { + struct xrep_bufscan scan = { + .daddr = XFS_AGB_TO_DADDR(mp, agno, bno), + .max_sectors = xrep_bufscan_max_sectors(mp, + scan_blocks), + .daddr_step = XFS_FSB_TO_BB(mp, 1), + }; + struct xfs_buf *bp; + + while ((bp = xrep_bufscan_advance(mp, &scan)) != NULL) { + if (xreap_buf_loggable(bp)) { + xfs_trans_bjoin(sc->tp, bp); + xfs_trans_binval(sc->tp, bp); + } else { + xfs_buf_stale(bp); + xfs_buf_relse(bp); + } + invalidated++; + + /* + * Stop invalidating if we've hit the limit; we should + * still have enough reservation left to free however + * much of the mapping we've seen so far. + */ + if (invalidated > XREAP_MAX_BINVAL) { + imap->br_blockcount = agbno_next - bno; + goto out; + } + } + + bno++; + scan_blocks--; + } + +out: + trace_xreap_bmapi_binval(sc->sa.pag, agbno, imap->br_blockcount); + return 0; +} + +/* + * Dispose of as much of the beginning of this file fork mapping as possible. + * The number of blocks disposed of is returned in @imap->br_blockcount. + */ +STATIC int +xrep_reap_bmapi_iter( + struct xfs_scrub *sc, + struct xfs_inode *ip, + int whichfork, + struct xfs_bmbt_irec *imap, + bool crosslinked) +{ + int error; + + if (crosslinked) { + /* + * If there are other rmappings, this block is cross linked and + * must not be freed. Remove the reverse mapping, leave the + * buffer cache in its possibly confused state, and move on. + * We don't want to risk discarding valid data buffers from + * anybody else who thinks they own the block, even though that + * runs the risk of stale buffer warnings in the future. + */ + trace_xreap_dispose_unmap_extent(sc->sa.pag, + XFS_FSB_TO_AGBNO(sc->mp, imap->br_startblock), + imap->br_blockcount); + + /* + * Schedule removal of the mapping from the fork. We use + * deferred log intents in this function to control the exact + * sequence of metadata updates. + */ + xfs_bmap_unmap_extent(sc->tp, ip, whichfork, imap); + xfs_trans_mod_dquot_byino(sc->tp, ip, XFS_TRANS_DQ_BCOUNT, + -(int64_t)imap->br_blockcount); + xfs_rmap_unmap_extent(sc->tp, ip, whichfork, imap); + return 0; + } + + /* + * If the block is not crosslinked, we can invalidate all the incore + * buffers for the extent, and then free the extent. This is a bit of + * a mess since we don't detect discontiguous buffers that are indexed + * by a block starting before the first block of the extent but overlap + * anyway. + */ + trace_xreap_dispose_free_extent(sc->sa.pag, + XFS_FSB_TO_AGBNO(sc->mp, imap->br_startblock), + imap->br_blockcount); + + /* + * Invalidate as many buffers as we can, starting at the beginning of + * this mapping. If this function sets blockcount to zero, the + * transaction is full of logged buffer invalidations, so we need to + * return early so that we can roll and retry. + */ + error = xreap_bmapi_binval(sc, ip, whichfork, imap); + if (error || imap->br_blockcount == 0) + return error; + + /* + * Schedule removal of the mapping from the fork. We use deferred log + * intents in this function to control the exact sequence of metadata + * updates. + */ + xfs_bmap_unmap_extent(sc->tp, ip, whichfork, imap); + xfs_trans_mod_dquot_byino(sc->tp, ip, XFS_TRANS_DQ_BCOUNT, + -(int64_t)imap->br_blockcount); + return xfs_free_extent_later(sc->tp, imap->br_startblock, + imap->br_blockcount, NULL, XFS_AG_RESV_NONE, true); +} + +/* + * Dispose of as much of this file extent as we can. Upon successful return, + * the imap will reflect the mapping that was removed from the fork. + */ +STATIC int +xreap_ifork_extent( + struct xfs_scrub *sc, + struct xfs_inode *ip, + int whichfork, + struct xfs_bmbt_irec *imap) +{ + xfs_agnumber_t agno; + bool crosslinked; + int error; + + ASSERT(sc->sa.pag == NULL); + + trace_xreap_ifork_extent(sc, ip, whichfork, imap); + + agno = XFS_FSB_TO_AGNO(sc->mp, imap->br_startblock); + sc->sa.pag = xfs_perag_get(sc->mp, agno); + if (!sc->sa.pag) + return -EFSCORRUPTED; + + error = xfs_alloc_read_agf(sc->sa.pag, sc->tp, 0, &sc->sa.agf_bp); + if (error) + goto out_pag; + + /* + * Decide the fate of the blocks at the beginning of the mapping, then + * update the mapping to use it with the unmap calls. + */ + error = xreap_bmapi_select(sc, ip, whichfork, imap, &crosslinked); + if (error) + goto out_agf; + + error = xrep_reap_bmapi_iter(sc, ip, whichfork, imap, crosslinked); + if (error) + goto out_agf; + +out_agf: + xfs_trans_brelse(sc->tp, sc->sa.agf_bp); + sc->sa.agf_bp = NULL; +out_pag: + xfs_perag_put(sc->sa.pag); + sc->sa.pag = NULL; + return error; +} + +/* + * Dispose of each block mapped to the given fork of the given file. Callers + * must hold ILOCK_EXCL, and ip can only be sc->ip or sc->tempip. The fork + * must not have any delalloc reservations. + */ +int +xrep_reap_ifork( + struct xfs_scrub *sc, + struct xfs_inode *ip, + int whichfork) +{ + xfs_fileoff_t off = 0; + int bmap_flags = xfs_bmapi_aflag(whichfork); + int error; + + ASSERT(xfs_has_rmapbt(sc->mp)); + ASSERT(ip == sc->ip || ip == sc->tempip); + ASSERT(whichfork == XFS_ATTR_FORK || !XFS_IS_REALTIME_INODE(ip)); + + while (off < XFS_MAX_FILEOFF) { + struct xfs_bmbt_irec imap; + int nimaps = 1; + + /* Read the next extent, skip past holes and delalloc. */ + error = xfs_bmapi_read(ip, off, XFS_MAX_FILEOFF - off, &imap, + &nimaps, bmap_flags); + if (error) + return error; + if (nimaps != 1 || imap.br_startblock == DELAYSTARTBLOCK) { + ASSERT(0); + return -EFSCORRUPTED; + } + + /* + * If this is a real space mapping, reap as much of it as we + * can in a single transaction. + */ + if (xfs_bmap_is_real_extent(&imap)) { + error = xreap_ifork_extent(sc, ip, whichfork, &imap); + if (error) + return error; + + error = xfs_defer_finish(&sc->tp); + if (error) + return error; + } + + off = imap.br_startoff + imap.br_blockcount; + } + + return 0; +} -- cgit v1.2.3