// SPDX-License-Identifier: GPL-2.0+ /* * Copyright (C) 2017 Oracle. All Rights Reserved. * Author: Darrick J. Wong */ #include "xfs.h" #include "xfs_fs.h" #include "xfs_shared.h" #include "xfs_format.h" #include "xfs_log_format.h" #include "xfs_trans_resv.h" #include "xfs_mount.h" #include "xfs_inode.h" #include "xfs_trans.h" #include "xfs_btree.h" #include "xfs_rmap_btree.h" #include "xfs_trace.h" #include "xfs_rmap.h" #include "xfs_alloc.h" #include "xfs_bit.h" #include #include "xfs_fsmap.h" #include "xfs_refcount.h" #include "xfs_refcount_btree.h" #include "xfs_alloc_btree.h" #include "xfs_rtalloc.h" #include "xfs_ag.h" /* Convert an xfs_fsmap to an fsmap. */ static void xfs_fsmap_from_internal( struct fsmap *dest, struct xfs_fsmap *src) { dest->fmr_device = src->fmr_device; dest->fmr_flags = src->fmr_flags; dest->fmr_physical = BBTOB(src->fmr_physical); dest->fmr_owner = src->fmr_owner; dest->fmr_offset = BBTOB(src->fmr_offset); dest->fmr_length = BBTOB(src->fmr_length); dest->fmr_reserved[0] = 0; dest->fmr_reserved[1] = 0; dest->fmr_reserved[2] = 0; } /* Convert an fsmap to an xfs_fsmap. */ void xfs_fsmap_to_internal( struct xfs_fsmap *dest, struct fsmap *src) { dest->fmr_device = src->fmr_device; dest->fmr_flags = src->fmr_flags; dest->fmr_physical = BTOBBT(src->fmr_physical); dest->fmr_owner = src->fmr_owner; dest->fmr_offset = BTOBBT(src->fmr_offset); dest->fmr_length = BTOBBT(src->fmr_length); } /* Convert an fsmap owner into an rmapbt owner. */ static int xfs_fsmap_owner_to_rmap( struct xfs_rmap_irec *dest, const struct xfs_fsmap *src) { if (!(src->fmr_flags & FMR_OF_SPECIAL_OWNER)) { dest->rm_owner = src->fmr_owner; return 0; } switch (src->fmr_owner) { case 0: /* "lowest owner id possible" */ case -1ULL: /* "highest owner id possible" */ dest->rm_owner = 0; break; case XFS_FMR_OWN_FREE: dest->rm_owner = XFS_RMAP_OWN_NULL; break; case XFS_FMR_OWN_UNKNOWN: dest->rm_owner = XFS_RMAP_OWN_UNKNOWN; break; case XFS_FMR_OWN_FS: dest->rm_owner = XFS_RMAP_OWN_FS; break; case XFS_FMR_OWN_LOG: dest->rm_owner = XFS_RMAP_OWN_LOG; break; case XFS_FMR_OWN_AG: dest->rm_owner = XFS_RMAP_OWN_AG; break; case XFS_FMR_OWN_INOBT: dest->rm_owner = XFS_RMAP_OWN_INOBT; break; case XFS_FMR_OWN_INODES: dest->rm_owner = XFS_RMAP_OWN_INODES; break; case XFS_FMR_OWN_REFC: dest->rm_owner = XFS_RMAP_OWN_REFC; break; case XFS_FMR_OWN_COW: dest->rm_owner = XFS_RMAP_OWN_COW; break; case XFS_FMR_OWN_DEFECTIVE: /* not implemented */ /* fall through */ default: return -EINVAL; } return 0; } /* Convert an rmapbt owner into an fsmap owner. */ static int xfs_fsmap_owner_from_rmap( struct xfs_fsmap *dest, const struct xfs_rmap_irec *src) { dest->fmr_flags = 0; if (!XFS_RMAP_NON_INODE_OWNER(src->rm_owner)) { dest->fmr_owner = src->rm_owner; return 0; } dest->fmr_flags |= FMR_OF_SPECIAL_OWNER; switch (src->rm_owner) { case XFS_RMAP_OWN_FS: dest->fmr_owner = XFS_FMR_OWN_FS; break; case XFS_RMAP_OWN_LOG: dest->fmr_owner = XFS_FMR_OWN_LOG; break; case XFS_RMAP_OWN_AG: dest->fmr_owner = XFS_FMR_OWN_AG; break; case XFS_RMAP_OWN_INOBT: dest->fmr_owner = XFS_FMR_OWN_INOBT; break; case XFS_RMAP_OWN_INODES: dest->fmr_owner = XFS_FMR_OWN_INODES; break; case XFS_RMAP_OWN_REFC: dest->fmr_owner = XFS_FMR_OWN_REFC; break; case XFS_RMAP_OWN_COW: dest->fmr_owner = XFS_FMR_OWN_COW; break; case XFS_RMAP_OWN_NULL: /* "free" */ dest->fmr_owner = XFS_FMR_OWN_FREE; break; default: ASSERT(0); return -EFSCORRUPTED; } return 0; } /* getfsmap query state */ struct xfs_getfsmap_info { struct xfs_fsmap_head *head; struct fsmap *fsmap_recs; /* mapping records */ struct xfs_buf *agf_bp; /* AGF, for refcount queries */ struct xfs_perag *pag; /* AG info, if applicable */ xfs_daddr_t next_daddr; /* next daddr we expect */ u64 missing_owner; /* owner of holes */ u32 dev; /* device id */ struct xfs_rmap_irec low; /* low rmap key */ struct xfs_rmap_irec high; /* high rmap key */ bool last; /* last extent? */ }; /* Associate a device with a getfsmap handler. */ struct xfs_getfsmap_dev { u32 dev; int (*fn)(struct xfs_trans *tp, const struct xfs_fsmap *keys, struct xfs_getfsmap_info *info); }; /* Compare two getfsmap device handlers. */ static int xfs_getfsmap_dev_compare( const void *p1, const void *p2) { const struct xfs_getfsmap_dev *d1 = p1; const struct xfs_getfsmap_dev *d2 = p2; return d1->dev - d2->dev; } /* Decide if this mapping is shared. */ STATIC int xfs_getfsmap_is_shared( struct xfs_trans *tp, struct xfs_getfsmap_info *info, const struct xfs_rmap_irec *rec, bool *stat) { struct xfs_mount *mp = tp->t_mountp; struct xfs_btree_cur *cur; xfs_agblock_t fbno; xfs_extlen_t flen; int error; *stat = false; if (!xfs_sb_version_hasreflink(&mp->m_sb)) return 0; /* rt files will have no perag structure */ if (!info->pag) return 0; /* Are there any shared blocks here? */ flen = 0; cur = xfs_refcountbt_init_cursor(mp, tp, info->agf_bp, info->pag); error = xfs_refcount_find_shared(cur, rec->rm_startblock, rec->rm_blockcount, &fbno, &flen, false); xfs_btree_del_cursor(cur, error); if (error) return error; *stat = flen > 0; return 0; } static inline void xfs_getfsmap_format( struct xfs_mount *mp, struct xfs_fsmap *xfm, struct xfs_getfsmap_info *info) { struct fsmap *rec; trace_xfs_getfsmap_mapping(mp, xfm); rec = &info->fsmap_recs[info->head->fmh_entries++]; xfs_fsmap_from_internal(rec, xfm); } /* * Format a reverse mapping for getfsmap, having translated rm_startblock * into the appropriate daddr units. */ STATIC int xfs_getfsmap_helper( struct xfs_trans *tp, struct xfs_getfsmap_info *info, const struct xfs_rmap_irec *rec, xfs_daddr_t rec_daddr) { struct xfs_fsmap fmr; struct xfs_mount *mp = tp->t_mountp; bool shared; int error; if (fatal_signal_pending(current)) return -EINTR; /* * Filter out records that start before our startpoint, if the * caller requested that. */ if (xfs_rmap_compare(rec, &info->low) < 0) { rec_daddr += XFS_FSB_TO_BB(mp, rec->rm_blockcount); if (info->next_daddr < rec_daddr) info->next_daddr = rec_daddr; return 0; } /* Are we just counting mappings? */ if (info->head->fmh_count == 0) { if (info->head->fmh_entries == UINT_MAX) return -ECANCELED; if (rec_daddr > info->next_daddr) info->head->fmh_entries++; if (info->last) return 0; info->head->fmh_entries++; rec_daddr += XFS_FSB_TO_BB(mp, rec->rm_blockcount); if (info->next_daddr < rec_daddr) info->next_daddr = rec_daddr; return 0; } /* * If the record starts past the last physical block we saw, * then we've found a gap. Report the gap as being owned by * whatever the caller specified is the missing owner. */ if (rec_daddr > info->next_daddr) { if (info->head->fmh_entries >= info->head->fmh_count) return -ECANCELED; fmr.fmr_device = info->dev; fmr.fmr_physical = info->next_daddr; fmr.fmr_owner = info->missing_owner; fmr.fmr_offset = 0; fmr.fmr_length = rec_daddr - info->next_daddr; fmr.fmr_flags = FMR_OF_SPECIAL_OWNER; xfs_getfsmap_format(mp, &fmr, info); } if (info->last) goto out; /* Fill out the extent we found */ if (info->head->fmh_entries >= info->head->fmh_count) return -ECANCELED; trace_xfs_fsmap_mapping(mp, info->dev, info->pag ? info->pag->pag_agno : NULLAGNUMBER, rec); fmr.fmr_device = info->dev; fmr.fmr_physical = rec_daddr; error = xfs_fsmap_owner_from_rmap(&fmr, rec); if (error) return error; fmr.fmr_offset = XFS_FSB_TO_BB(mp, rec->rm_offset); fmr.fmr_length = XFS_FSB_TO_BB(mp, rec->rm_blockcount); if (rec->rm_flags & XFS_RMAP_UNWRITTEN) fmr.fmr_flags |= FMR_OF_PREALLOC; if (rec->rm_flags & XFS_RMAP_ATTR_FORK) fmr.fmr_flags |= FMR_OF_ATTR_FORK; if (rec->rm_flags & XFS_RMAP_BMBT_BLOCK) fmr.fmr_flags |= FMR_OF_EXTENT_MAP; if (fmr.fmr_flags == 0) { error = xfs_getfsmap_is_shared(tp, info, rec, &shared); if (error) return error; if (shared) fmr.fmr_flags |= FMR_OF_SHARED; } xfs_getfsmap_format(mp, &fmr, info); out: rec_daddr += XFS_FSB_TO_BB(mp, rec->rm_blockcount); if (info->next_daddr < rec_daddr) info->next_daddr = rec_daddr; return 0; } /* Transform a rmapbt irec into a fsmap */ STATIC int xfs_getfsmap_datadev_helper( struct xfs_btree_cur *cur, const struct xfs_rmap_irec *rec, void *priv) { struct xfs_mount *mp = cur->bc_mp; struct xfs_getfsmap_info *info = priv; xfs_fsblock_t fsb; xfs_daddr_t rec_daddr; fsb = XFS_AGB_TO_FSB(mp, cur->bc_ag.pag->pag_agno, rec->rm_startblock); rec_daddr = XFS_FSB_TO_DADDR(mp, fsb); return xfs_getfsmap_helper(cur->bc_tp, info, rec, rec_daddr); } /* Transform a bnobt irec into a fsmap */ STATIC int xfs_getfsmap_datadev_bnobt_helper( struct xfs_btree_cur *cur, const struct xfs_alloc_rec_incore *rec, void *priv) { struct xfs_mount *mp = cur->bc_mp; struct xfs_getfsmap_info *info = priv; struct xfs_rmap_irec irec; xfs_daddr_t rec_daddr; rec_daddr = XFS_AGB_TO_DADDR(mp, cur->bc_ag.pag->pag_agno, rec->ar_startblock); irec.rm_startblock = rec->ar_startblock; irec.rm_blockcount = rec->ar_blockcount; irec.rm_owner = XFS_RMAP_OWN_NULL; /* "free" */ irec.rm_offset = 0; irec.rm_flags = 0; return xfs_getfsmap_helper(cur->bc_tp, info, &irec, rec_daddr); } /* Set rmap flags based on the getfsmap flags */ static void xfs_getfsmap_set_irec_flags( struct xfs_rmap_irec *irec, const struct xfs_fsmap *fmr) { irec->rm_flags = 0; if (fmr->fmr_flags & FMR_OF_ATTR_FORK) irec->rm_flags |= XFS_RMAP_ATTR_FORK; if (fmr->fmr_flags & FMR_OF_EXTENT_MAP) irec->rm_flags |= XFS_RMAP_BMBT_BLOCK; if (fmr->fmr_flags & FMR_OF_PREALLOC) irec->rm_flags |= XFS_RMAP_UNWRITTEN; } /* Execute a getfsmap query against the log device. */ STATIC int xfs_getfsmap_logdev( struct xfs_trans *tp, const struct xfs_fsmap *keys, struct xfs_getfsmap_info *info) { struct xfs_mount *mp = tp->t_mountp; struct xfs_rmap_irec rmap; int error; /* Set up search keys */ info->low.rm_startblock = XFS_BB_TO_FSBT(mp, keys[0].fmr_physical); info->low.rm_offset = XFS_BB_TO_FSBT(mp, keys[0].fmr_offset); error = xfs_fsmap_owner_to_rmap(&info->low, keys); if (error) return error; info->low.rm_blockcount = 0; xfs_getfsmap_set_irec_flags(&info->low, &keys[0]); error = xfs_fsmap_owner_to_rmap(&info->high, keys + 1); if (error) return error; info->high.rm_startblock = -1U; info->high.rm_owner = ULLONG_MAX; info->high.rm_offset = ULLONG_MAX; info->high.rm_blockcount = 0; info->high.rm_flags = XFS_RMAP_KEY_FLAGS | XFS_RMAP_REC_FLAGS; info->missing_owner = XFS_FMR_OWN_FREE; trace_xfs_fsmap_low_key(mp, info->dev, NULLAGNUMBER, &info->low); trace_xfs_fsmap_high_key(mp, info->dev, NULLAGNUMBER, &info->high); if (keys[0].fmr_physical > 0) return 0; /* Fabricate an rmap entry for the external log device. */ rmap.rm_startblock = 0; rmap.rm_blockcount = mp->m_sb.sb_logblocks; rmap.rm_owner = XFS_RMAP_OWN_LOG; rmap.rm_offset = 0; rmap.rm_flags = 0; return xfs_getfsmap_helper(tp, info, &rmap, 0); } #ifdef CONFIG_XFS_RT /* Transform a rtbitmap "record" into a fsmap */ STATIC int xfs_getfsmap_rtdev_rtbitmap_helper( struct xfs_trans *tp, const struct xfs_rtalloc_rec *rec, void *priv) { struct xfs_mount *mp = tp->t_mountp; struct xfs_getfsmap_info *info = priv; struct xfs_rmap_irec irec; xfs_daddr_t rec_daddr; irec.rm_startblock = rec->ar_startext * mp->m_sb.sb_rextsize; rec_daddr = XFS_FSB_TO_BB(mp, irec.rm_startblock); irec.rm_blockcount = rec->ar_extcount * mp->m_sb.sb_rextsize; irec.rm_owner = XFS_RMAP_OWN_NULL; /* "free" */ irec.rm_offset = 0; irec.rm_flags = 0; return xfs_getfsmap_helper(tp, info, &irec, rec_daddr); } /* Execute a getfsmap query against the realtime device. */ STATIC int __xfs_getfsmap_rtdev( struct xfs_trans *tp, const struct xfs_fsmap *keys, int (*query_fn)(struct xfs_trans *, struct xfs_getfsmap_info *), struct xfs_getfsmap_info *info) { struct xfs_mount *mp = tp->t_mountp; xfs_fsblock_t start_fsb; xfs_fsblock_t end_fsb; uint64_t eofs; int error = 0; eofs = XFS_FSB_TO_BB(mp, mp->m_sb.sb_rblocks); if (keys[0].fmr_physical >= eofs) return 0; start_fsb = XFS_BB_TO_FSBT(mp, keys[0].fmr_physical); end_fsb = XFS_BB_TO_FSB(mp, min(eofs - 1, keys[1].fmr_physical)); /* Set up search keys */ info->low.rm_startblock = start_fsb; error = xfs_fsmap_owner_to_rmap(&info->low, &keys[0]); if (error) return error; info->low.rm_offset = XFS_BB_TO_FSBT(mp, keys[0].fmr_offset); info->low.rm_blockcount = 0; xfs_getfsmap_set_irec_flags(&info->low, &keys[0]); info->high.rm_startblock = end_fsb; error = xfs_fsmap_owner_to_rmap(&info->high, &keys[1]); if (error) return error; info->high.rm_offset = XFS_BB_TO_FSBT(mp, keys[1].fmr_offset); info->high.rm_blockcount = 0; xfs_getfsmap_set_irec_flags(&info->high, &keys[1]); trace_xfs_fsmap_low_key(mp, info->dev, NULLAGNUMBER, &info->low); trace_xfs_fsmap_high_key(mp, info->dev, NULLAGNUMBER, &info->high); return query_fn(tp, info); } /* Actually query the realtime bitmap. */ STATIC int xfs_getfsmap_rtdev_rtbitmap_query( struct xfs_trans *tp, struct xfs_getfsmap_info *info) { struct xfs_rtalloc_rec alow = { 0 }; struct xfs_rtalloc_rec ahigh = { 0 }; struct xfs_mount *mp = tp->t_mountp; int error; xfs_ilock(mp->m_rbmip, XFS_ILOCK_SHARED); /* * Set up query parameters to return free rtextents covering the range * we want. */ alow.ar_startext = info->low.rm_startblock; ahigh.ar_startext = info->high.rm_startblock; do_div(alow.ar_startext, mp->m_sb.sb_rextsize); if (do_div(ahigh.ar_startext, mp->m_sb.sb_rextsize)) ahigh.ar_startext++; error = xfs_rtalloc_query_range(tp, &alow, &ahigh, xfs_getfsmap_rtdev_rtbitmap_helper, info); if (error) goto err; /* * Report any gaps at the end of the rtbitmap by simulating a null * rmap starting at the block after the end of the query range. */ info->last = true; ahigh.ar_startext = min(mp->m_sb.sb_rextents, ahigh.ar_startext); error = xfs_getfsmap_rtdev_rtbitmap_helper(tp, &ahigh, info); if (error) goto err; err: xfs_iunlock(mp->m_rbmip, XFS_ILOCK_SHARED); return error; } /* Execute a getfsmap query against the realtime device rtbitmap. */ STATIC int xfs_getfsmap_rtdev_rtbitmap( struct xfs_trans *tp, const struct xfs_fsmap *keys, struct xfs_getfsmap_info *info) { info->missing_owner = XFS_FMR_OWN_UNKNOWN; return __xfs_getfsmap_rtdev(tp, keys, xfs_getfsmap_rtdev_rtbitmap_query, info); } #endif /* CONFIG_XFS_RT */ /* Execute a getfsmap query against the regular data device. */ STATIC int __xfs_getfsmap_datadev( struct xfs_trans *tp, const struct xfs_fsmap *keys, struct xfs_getfsmap_info *info, int (*query_fn)(struct xfs_trans *, struct xfs_getfsmap_info *, struct xfs_btree_cur **, void *), void *priv) { struct xfs_mount *mp = tp->t_mountp; struct xfs_perag *pag; struct xfs_btree_cur *bt_cur = NULL; xfs_fsblock_t start_fsb; xfs_fsblock_t end_fsb; xfs_agnumber_t start_ag; xfs_agnumber_t end_ag; uint64_t eofs; int error = 0; eofs = XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks); if (keys[0].fmr_physical >= eofs) return 0; start_fsb = XFS_DADDR_TO_FSB(mp, keys[0].fmr_physical); end_fsb = XFS_DADDR_TO_FSB(mp, min(eofs - 1, keys[1].fmr_physical)); /* * Convert the fsmap low/high keys to AG based keys. Initialize * low to the fsmap low key and max out the high key to the end * of the AG. */ info->low.rm_startblock = XFS_FSB_TO_AGBNO(mp, start_fsb); info->low.rm_offset = XFS_BB_TO_FSBT(mp, keys[0].fmr_offset); error = xfs_fsmap_owner_to_rmap(&info->low, &keys[0]); if (error) return error; info->low.rm_blockcount = 0; xfs_getfsmap_set_irec_flags(&info->low, &keys[0]); info->high.rm_startblock = -1U; info->high.rm_owner = ULLONG_MAX; info->high.rm_offset = ULLONG_MAX; info->high.rm_blockcount = 0; info->high.rm_flags = XFS_RMAP_KEY_FLAGS | XFS_RMAP_REC_FLAGS; start_ag = XFS_FSB_TO_AGNO(mp, start_fsb); end_ag = XFS_FSB_TO_AGNO(mp, end_fsb); for_each_perag_range(mp, start_ag, end_ag, pag) { /* * Set the AG high key from the fsmap high key if this * is the last AG that we're querying. */ info->pag = pag; if (pag->pag_agno == end_ag) { info->high.rm_startblock = XFS_FSB_TO_AGBNO(mp, end_fsb); info->high.rm_offset = XFS_BB_TO_FSBT(mp, keys[1].fmr_offset); error = xfs_fsmap_owner_to_rmap(&info->high, &keys[1]); if (error) break; xfs_getfsmap_set_irec_flags(&info->high, &keys[1]); } if (bt_cur) { xfs_btree_del_cursor(bt_cur, XFS_BTREE_NOERROR); bt_cur = NULL; xfs_trans_brelse(tp, info->agf_bp); info->agf_bp = NULL; } error = xfs_alloc_read_agf(mp, tp, pag->pag_agno, 0, &info->agf_bp); if (error) break; trace_xfs_fsmap_low_key(mp, info->dev, pag->pag_agno, &info->low); trace_xfs_fsmap_high_key(mp, info->dev, pag->pag_agno, &info->high); error = query_fn(tp, info, &bt_cur, priv); if (error) break; /* * Set the AG low key to the start of the AG prior to * moving on to the next AG. */ if (pag->pag_agno == start_ag) { info->low.rm_startblock = 0; info->low.rm_owner = 0; info->low.rm_offset = 0; info->low.rm_flags = 0; } /* * If this is the last AG, report any gap at the end of it * before we drop the reference to the perag when the loop * terminates. */ if (pag->pag_agno == end_ag) { info->last = true; error = query_fn(tp, info, &bt_cur, priv); if (error) break; } info->pag = NULL; } if (bt_cur) xfs_btree_del_cursor(bt_cur, error < 0 ? XFS_BTREE_ERROR : XFS_BTREE_NOERROR); if (info->agf_bp) { xfs_trans_brelse(tp, info->agf_bp); info->agf_bp = NULL; } if (info->pag) { xfs_perag_put(info->pag); info->pag = NULL; } else if (pag) { /* loop termination case */ xfs_perag_put(pag); } return error; } /* Actually query the rmap btree. */ STATIC int xfs_getfsmap_datadev_rmapbt_query( struct xfs_trans *tp, struct xfs_getfsmap_info *info, struct xfs_btree_cur **curpp, void *priv) { /* Report any gap at the end of the last AG. */ if (info->last) return xfs_getfsmap_datadev_helper(*curpp, &info->high, info); /* Allocate cursor for this AG and query_range it. */ *curpp = xfs_rmapbt_init_cursor(tp->t_mountp, tp, info->agf_bp, info->pag); return xfs_rmap_query_range(*curpp, &info->low, &info->high, xfs_getfsmap_datadev_helper, info); } /* Execute a getfsmap query against the regular data device rmapbt. */ STATIC int xfs_getfsmap_datadev_rmapbt( struct xfs_trans *tp, const struct xfs_fsmap *keys, struct xfs_getfsmap_info *info) { info->missing_owner = XFS_FMR_OWN_FREE; return __xfs_getfsmap_datadev(tp, keys, info, xfs_getfsmap_datadev_rmapbt_query, NULL); } /* Actually query the bno btree. */ STATIC int xfs_getfsmap_datadev_bnobt_query( struct xfs_trans *tp, struct xfs_getfsmap_info *info, struct xfs_btree_cur **curpp, void *priv) { struct xfs_alloc_rec_incore *key = priv; /* Report any gap at the end of the last AG. */ if (info->last) return xfs_getfsmap_datadev_bnobt_helper(*curpp, &key[1], info); /* Allocate cursor for this AG and query_range it. */ *curpp = xfs_allocbt_init_cursor(tp->t_mountp, tp, info->agf_bp, info->pag, XFS_BTNUM_BNO); key->ar_startblock = info->low.rm_startblock; key[1].ar_startblock = info->high.rm_startblock; return xfs_alloc_query_range(*curpp, key, &key[1], xfs_getfsmap_datadev_bnobt_helper, info); } /* Execute a getfsmap query against the regular data device's bnobt. */ STATIC int xfs_getfsmap_datadev_bnobt( struct xfs_trans *tp, const struct xfs_fsmap *keys, struct xfs_getfsmap_info *info) { struct xfs_alloc_rec_incore akeys[2]; info->missing_owner = XFS_FMR_OWN_UNKNOWN; return __xfs_getfsmap_datadev(tp, keys, info, xfs_getfsmap_datadev_bnobt_query, &akeys[0]); } /* Do we recognize the device? */ STATIC bool xfs_getfsmap_is_valid_device( struct xfs_mount *mp, struct xfs_fsmap *fm) { if (fm->fmr_device == 0 || fm->fmr_device == UINT_MAX || fm->fmr_device == new_encode_dev(mp->m_ddev_targp->bt_dev)) return true; if (mp->m_logdev_targp && fm->fmr_device == new_encode_dev(mp->m_logdev_targp->bt_dev)) return true; if (mp->m_rtdev_targp && fm->fmr_device == new_encode_dev(mp->m_rtdev_targp->bt_dev)) return true; return false; } /* Ensure that the low key is less than the high key. */ STATIC bool xfs_getfsmap_check_keys( struct xfs_fsmap *low_key, struct xfs_fsmap *high_key) { if (low_key->fmr_device > high_key->fmr_device) return false; if (low_key->fmr_device < high_key->fmr_device) return true; if (low_key->fmr_physical > high_key->fmr_physical) return false; if (low_key->fmr_physical < high_key->fmr_physical) return true; if (low_key->fmr_owner > high_key->fmr_owner) return false; if (low_key->fmr_owner < high_key->fmr_owner) return true; if (low_key->fmr_offset > high_key->fmr_offset) return false; if (low_key->fmr_offset < high_key->fmr_offset) return true; return false; } /* * There are only two devices if we didn't configure RT devices at build time. */ #ifdef CONFIG_XFS_RT #define XFS_GETFSMAP_DEVS 3 #else #define XFS_GETFSMAP_DEVS 2 #endif /* CONFIG_XFS_RT */ /* * Get filesystem's extents as described in head, and format for output. Fills * in the supplied records array until there are no more reverse mappings to * return or head.fmh_entries == head.fmh_count. In the second case, this * function returns -ECANCELED to indicate that more records would have been * returned. * * Key to Confusion * ---------------- * There are multiple levels of keys and counters at work here: * xfs_fsmap_head.fmh_keys -- low and high fsmap keys passed in; * these reflect fs-wide sector addrs. * dkeys -- fmh_keys used to query each device; * these are fmh_keys but w/ the low key * bumped up by fmr_length. * xfs_getfsmap_info.next_daddr -- next disk addr we expect to see; this * is how we detect gaps in the fsmap records and report them. * xfs_getfsmap_info.low/high -- per-AG low/high keys computed from * dkeys; used to query the metadata. */ int xfs_getfsmap( struct xfs_mount *mp, struct xfs_fsmap_head *head, struct fsmap *fsmap_recs) { struct xfs_trans *tp = NULL; struct xfs_fsmap dkeys[2]; /* per-dev keys */ struct xfs_getfsmap_dev handlers[XFS_GETFSMAP_DEVS]; struct xfs_getfsmap_info info = { NULL }; bool use_rmap; int i; int error = 0; if (head->fmh_iflags & ~FMH_IF_VALID) return -EINVAL; if (!xfs_getfsmap_is_valid_device(mp, &head->fmh_keys[0]) || !xfs_getfsmap_is_valid_device(mp, &head->fmh_keys[1])) return -EINVAL; use_rmap = capable(CAP_SYS_ADMIN) && xfs_sb_version_hasrmapbt(&mp->m_sb); head->fmh_entries = 0; /* Set up our device handlers. */ memset(handlers, 0, sizeof(handlers)); handlers[0].dev = new_encode_dev(mp->m_ddev_targp->bt_dev); if (use_rmap) handlers[0].fn = xfs_getfsmap_datadev_rmapbt; else handlers[0].fn = xfs_getfsmap_datadev_bnobt; if (mp->m_logdev_targp != mp->m_ddev_targp) { handlers[1].dev = new_encode_dev(mp->m_logdev_targp->bt_dev); handlers[1].fn = xfs_getfsmap_logdev; } #ifdef CONFIG_XFS_RT if (mp->m_rtdev_targp) { handlers[2].dev = new_encode_dev(mp->m_rtdev_targp->bt_dev); handlers[2].fn = xfs_getfsmap_rtdev_rtbitmap; } #endif /* CONFIG_XFS_RT */ xfs_sort(handlers, XFS_GETFSMAP_DEVS, sizeof(struct xfs_getfsmap_dev), xfs_getfsmap_dev_compare); /* * To continue where we left off, we allow userspace to use the * last mapping from a previous call as the low key of the next. * This is identified by a non-zero length in the low key. We * have to increment the low key in this scenario to ensure we * don't return the same mapping again, and instead return the * very next mapping. * * If the low key mapping refers to file data, the same physical * blocks could be mapped to several other files/offsets. * According to rmapbt record ordering, the minimal next * possible record for the block range is the next starting * offset in the same inode. Therefore, bump the file offset to * continue the search appropriately. For all other low key * mapping types (attr blocks, metadata), bump the physical * offset as there can be no other mapping for the same physical * block range. */ dkeys[0] = head->fmh_keys[0]; if (dkeys[0].fmr_flags & (FMR_OF_SPECIAL_OWNER | FMR_OF_EXTENT_MAP)) { dkeys[0].fmr_physical += dkeys[0].fmr_length; dkeys[0].fmr_owner = 0; if (dkeys[0].fmr_offset) return -EINVAL; } else dkeys[0].fmr_offset += dkeys[0].fmr_length; dkeys[0].fmr_length = 0; memset(&dkeys[1], 0xFF, sizeof(struct xfs_fsmap)); if (!xfs_getfsmap_check_keys(dkeys, &head->fmh_keys[1])) return -EINVAL; info.next_daddr = head->fmh_keys[0].fmr_physical + head->fmh_keys[0].fmr_length; info.fsmap_recs = fsmap_recs; info.head = head; /* For each device we support... */ for (i = 0; i < XFS_GETFSMAP_DEVS; i++) { /* Is this device within the range the user asked for? */ if (!handlers[i].fn) continue; if (head->fmh_keys[0].fmr_device > handlers[i].dev) continue; if (head->fmh_keys[1].fmr_device < handlers[i].dev) break; /* * If this device number matches the high key, we have * to pass the high key to the handler to limit the * query results. If the device number exceeds the * low key, zero out the low key so that we get * everything from the beginning. */ if (handlers[i].dev == head->fmh_keys[1].fmr_device) dkeys[1] = head->fmh_keys[1]; if (handlers[i].dev > head->fmh_keys[0].fmr_device) memset(&dkeys[0], 0, sizeof(struct xfs_fsmap)); /* * Grab an empty transaction so that we can use its recursive * buffer locking abilities to detect cycles in the rmapbt * without deadlocking. */ error = xfs_trans_alloc_empty(mp, &tp); if (error) break; info.dev = handlers[i].dev; info.last = false; info.pag = NULL; error = handlers[i].fn(tp, dkeys, &info); if (error) break; xfs_trans_cancel(tp); tp = NULL; info.next_daddr = 0; } if (tp) xfs_trans_cancel(tp); head->fmh_oflags = FMH_OF_DEV_T; return error; }