diff options
Diffstat (limited to 'fs/xfs/xfs_fsmap.c')
| -rw-r--r-- | fs/xfs/xfs_fsmap.c | 974 |
1 files changed, 974 insertions, 0 deletions
diff --git a/fs/xfs/xfs_fsmap.c b/fs/xfs/xfs_fsmap.c new file mode 100644 index 000000000..d8337274c --- /dev/null +++ b/fs/xfs/xfs_fsmap.c @@ -0,0 +1,974 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2017 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_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 <linux/fsmap.h> +#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_has_reflink(mp)) + 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_mount *mp, + struct xfs_trans *tp, + const struct xfs_rtalloc_rec *rec, + void *priv) +{ + 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(mp, 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(mp, 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(pag, tp, 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 = xfs_has_rmapbt(mp) && + has_capability_noaudit(current, CAP_SYS_ADMIN); + 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; +} |