diff options
Diffstat (limited to 'fs/xfs/xfs_fsmap.c')
| -rw-r--r-- | fs/xfs/xfs_fsmap.c | 1428 |
1 files changed, 1428 insertions, 0 deletions
diff --git a/fs/xfs/xfs_fsmap.c b/fs/xfs/xfs_fsmap.c new file mode 100644 index 000000000000..af68c7de8ee8 --- /dev/null +++ b/fs/xfs/xfs_fsmap.c @@ -0,0 +1,1428 @@ +// 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_rtbitmap.h" +#include "xfs_ag.h" +#include "xfs_rtgroup.h" +#include "xfs_rtrmap_btree.h" +#include "xfs_rtrefcount_btree.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. */ +static 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 = src->fmr_owner; + 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_frec( + struct xfs_fsmap *dest, + const struct xfs_fsmap_irec *frec) +{ + dest->fmr_flags = 0; + if (!XFS_RMAP_NON_INODE_OWNER(frec->owner)) { + dest->fmr_owner = frec->owner; + return 0; + } + dest->fmr_flags |= FMR_OF_SPECIAL_OWNER; + + switch (frec->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_group *group; /* group info, if applicable */ + xfs_daddr_t next_daddr; /* next daddr we expect */ + /* daddr of low fsmap key when we're using the rtbitmap */ + xfs_daddr_t low_daddr; + /* daddr of high fsmap key, or the last daddr on the device */ + xfs_daddr_t end_daddr; + u64 missing_owner; /* owner of holes */ + u32 dev; /* device id */ + /* + * Low rmap key for the query. If low.rm_blockcount is nonzero, this + * is the second (or later) call to retrieve the recordset in pieces. + * xfs_getfsmap_rec_before_start will compare all records retrieved + * by the rmapbt query to filter out any records that start before + * the last record. + */ + struct xfs_rmap_irec low; + 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); + sector_t nr_sectors; +}; + +/* 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_fsmap_irec *frec, + bool *stat) +{ + struct xfs_mount *mp = tp->t_mountp; + struct xfs_btree_cur *cur; + xfs_agblock_t fbno; + xfs_extlen_t flen = 0; + int error; + + *stat = false; + if (!xfs_has_reflink(mp) || !info->group) + return 0; + + if (info->group->xg_type == XG_TYPE_RTG) + cur = xfs_rtrefcountbt_init_cursor(tp, to_rtg(info->group)); + else + cur = xfs_refcountbt_init_cursor(mp, tp, info->agf_bp, + to_perag(info->group)); + + /* Are there any shared blocks here? */ + error = xfs_refcount_find_shared(cur, frec->rec_key, + XFS_BB_TO_FSBT(mp, frec->len_daddr), &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); +} + +static inline bool +xfs_getfsmap_frec_before_start( + struct xfs_getfsmap_info *info, + const struct xfs_fsmap_irec *frec) +{ + if (info->low_daddr != XFS_BUF_DADDR_NULL) + return frec->start_daddr < info->low_daddr; + if (info->low.rm_blockcount) { + struct xfs_rmap_irec rec = { + .rm_startblock = frec->rec_key, + .rm_owner = frec->owner, + .rm_flags = frec->rm_flags, + }; + + return xfs_rmap_compare(&rec, &info->low) < 0; + } + + return false; +} + +/* + * Format a reverse mapping for getfsmap, having translated rm_startblock + * into the appropriate daddr units. Pass in a nonzero @len_daddr if the + * length could be larger than rm_blockcount in struct xfs_rmap_irec. + */ +STATIC int +xfs_getfsmap_helper( + struct xfs_trans *tp, + struct xfs_getfsmap_info *info, + const struct xfs_fsmap_irec *frec) +{ + struct xfs_fsmap fmr; + struct xfs_mount *mp = tp->t_mountp; + bool shared; + int error = 0; + + if (fatal_signal_pending(current)) + return -EINTR; + + /* + * Filter out records that start before our startpoint, if the + * caller requested that. + */ + if (xfs_getfsmap_frec_before_start(info, frec)) + goto out; + + /* Are we just counting mappings? */ + if (info->head->fmh_count == 0) { + if (info->head->fmh_entries == UINT_MAX) + return -ECANCELED; + + if (frec->start_daddr > info->next_daddr) + info->head->fmh_entries++; + + if (info->last) + return 0; + + info->head->fmh_entries++; + goto out; + } + + /* + * 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 (frec->start_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 = frec->start_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->group ? info->group->xg_gno : NULLAGNUMBER, + frec); + + fmr.fmr_device = info->dev; + fmr.fmr_physical = frec->start_daddr; + error = xfs_fsmap_owner_from_frec(&fmr, frec); + if (error) + return error; + fmr.fmr_offset = XFS_FSB_TO_BB(mp, frec->offset); + fmr.fmr_length = frec->len_daddr; + if (frec->rm_flags & XFS_RMAP_UNWRITTEN) + fmr.fmr_flags |= FMR_OF_PREALLOC; + if (frec->rm_flags & XFS_RMAP_ATTR_FORK) + fmr.fmr_flags |= FMR_OF_ATTR_FORK; + if (frec->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, frec, &shared); + if (error) + return error; + if (shared) + fmr.fmr_flags |= FMR_OF_SHARED; + } + + xfs_getfsmap_format(mp, &fmr, info); +out: + info->next_daddr = max(info->next_daddr, + frec->start_daddr + frec->len_daddr); + return 0; +} + +static inline int +xfs_getfsmap_group_helper( + struct xfs_getfsmap_info *info, + struct xfs_trans *tp, + struct xfs_group *xg, + xfs_agblock_t startblock, + xfs_extlen_t blockcount, + struct xfs_fsmap_irec *frec) +{ + /* + * For an info->last query, we're looking for a gap between the last + * mapping emitted and the high key specified by userspace. If the + * user's query spans less than 1 fsblock, then info->high and + * info->low will have the same rm_startblock, which causes rec_daddr + * and next_daddr to be the same. Therefore, use the end_daddr that + * we calculated from userspace's high key to synthesize the record. + * Note that if the btree query found a mapping, there won't be a gap. + */ + if (info->last) + frec->start_daddr = info->end_daddr + 1; + else + frec->start_daddr = xfs_gbno_to_daddr(xg, startblock); + + frec->len_daddr = XFS_FSB_TO_BB(xg->xg_mount, blockcount); + return xfs_getfsmap_helper(tp, info, frec); +} + +/* Transform a rmapbt irec into a fsmap */ +STATIC int +xfs_getfsmap_rmapbt_helper( + struct xfs_btree_cur *cur, + const struct xfs_rmap_irec *rec, + void *priv) +{ + struct xfs_fsmap_irec frec = { + .owner = rec->rm_owner, + .offset = rec->rm_offset, + .rm_flags = rec->rm_flags, + .rec_key = rec->rm_startblock, + }; + struct xfs_getfsmap_info *info = priv; + + return xfs_getfsmap_group_helper(info, cur->bc_tp, cur->bc_group, + rec->rm_startblock, rec->rm_blockcount, &frec); +} + +/* 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_fsmap_irec frec = { + .owner = XFS_RMAP_OWN_NULL, /* "free" */ + .rec_key = rec->ar_startblock, + }; + struct xfs_getfsmap_info *info = priv; + + return xfs_getfsmap_group_helper(info, cur->bc_tp, cur->bc_group, + rec->ar_startblock, rec->ar_blockcount, &frec); +} + +/* 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; +} + +static inline bool +rmap_not_shareable(struct xfs_mount *mp, const struct xfs_rmap_irec *r) +{ + if (!xfs_has_reflink(mp)) + return true; + if (XFS_RMAP_NON_INODE_OWNER(r->rm_owner)) + return true; + if (r->rm_flags & (XFS_RMAP_ATTR_FORK | XFS_RMAP_BMBT_BLOCK | + XFS_RMAP_UNWRITTEN)) + return true; + return false; +} + +/* 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 = NULL; + struct xfs_btree_cur *bt_cur = NULL; + xfs_fsblock_t start_fsb; + xfs_fsblock_t end_fsb; + xfs_agnumber_t start_ag, 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_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 = XFS_BB_TO_FSBT(mp, keys[0].fmr_length); + xfs_getfsmap_set_irec_flags(&info->low, &keys[0]); + + /* Adjust the low key if we are continuing from where we left off. */ + if (info->low.rm_blockcount == 0) { + /* No previous record from which to continue */ + } else if (rmap_not_shareable(mp, &info->low)) { + /* Last record seen was an unshareable extent */ + info->low.rm_owner = 0; + info->low.rm_offset = 0; + + start_fsb += info->low.rm_blockcount; + if (XFS_FSB_TO_DADDR(mp, start_fsb) >= eofs) + return 0; + } else { + /* Last record seen was a shareable file data extent */ + info->low.rm_offset += info->low.rm_blockcount; + } + info->low.rm_startblock = XFS_FSB_TO_AGBNO(mp, start_fsb); + + 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); + + while ((pag = xfs_perag_next_range(mp, pag, start_ag, end_ag))) { + /* + * Set the AG high key from the fsmap high key if this + * is the last AG that we're querying. + */ + info->group = pag_group(pag); + if (pag_agno(pag) == 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_group_key(mp, info->dev, pag_agno(pag), + &info->low); + trace_xfs_fsmap_high_group_key(mp, info->dev, pag_agno(pag), + &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_agno(pag) == start_ag) + memset(&info->low, 0, sizeof(info->low)); + + /* + * 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_agno(pag) == end_ag) { + info->last = true; + error = query_fn(tp, info, &bt_cur, priv); + if (error) + break; + } + info->group = 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->group) { + xfs_perag_rele(pag); + info->group = NULL; + } else if (pag) { + /* loop termination case */ + xfs_perag_rele(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_rmapbt_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, + to_perag(info->group)); + return xfs_rmap_query_range(*curpp, &info->low, &info->high, + xfs_getfsmap_rmapbt_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_bnobt_init_cursor(tp->t_mountp, tp, info->agf_bp, + to_perag(info->group)); + 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]; + + memset(akeys, 0, sizeof(akeys)); + info->missing_owner = XFS_FMR_OWN_UNKNOWN; + return __xfs_getfsmap_datadev(tp, keys, info, + xfs_getfsmap_datadev_bnobt_query, &akeys[0]); +} + +/* 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_fsmap_irec frec = { + .start_daddr = 0, + .rec_key = 0, + .owner = XFS_RMAP_OWN_LOG, + }; + struct xfs_mount *mp = tp->t_mountp; + xfs_fsblock_t start_fsb, end_fsb; + uint64_t eofs; + + eofs = XFS_FSB_TO_BB(mp, mp->m_sb.sb_logblocks); + if (keys[0].fmr_physical >= eofs) + return 0; + start_fsb = XFS_BB_TO_FSBT(mp, + keys[0].fmr_physical + keys[0].fmr_length); + end_fsb = XFS_BB_TO_FSB(mp, min(eofs - 1, keys[1].fmr_physical)); + + /* Adjust the low key if we are continuing from where we left off. */ + if (keys[0].fmr_length > 0) + info->low_daddr = XFS_FSB_TO_BB(mp, start_fsb); + + trace_xfs_fsmap_low_linear_key(mp, info->dev, start_fsb); + trace_xfs_fsmap_high_linear_key(mp, info->dev, end_fsb); + + if (start_fsb > 0) + return 0; + + /* Fabricate an rmap entry for the external log device. */ + frec.len_daddr = XFS_FSB_TO_BB(mp, mp->m_sb.sb_logblocks); + return xfs_getfsmap_helper(tp, info, &frec); +} + +#ifdef CONFIG_XFS_RT +/* Transform a rtbitmap "record" into a fsmap */ +STATIC int +xfs_getfsmap_rtdev_rtbitmap_helper( + struct xfs_rtgroup *rtg, + struct xfs_trans *tp, + const struct xfs_rtalloc_rec *rec, + void *priv) +{ + struct xfs_fsmap_irec frec = { + .owner = XFS_RMAP_OWN_NULL, /* "free" */ + }; + struct xfs_mount *mp = rtg_mount(rtg); + struct xfs_getfsmap_info *info = priv; + xfs_rtblock_t start_rtb = + xfs_rtx_to_rtb(rtg, rec->ar_startext); + uint64_t rtbcount = + xfs_rtbxlen_to_blen(mp, rec->ar_extcount); + + /* + * For an info->last query, we're looking for a gap between the last + * mapping emitted and the high key specified by userspace. If the + * user's query spans less than 1 fsblock, then info->high and + * info->low will have the same rm_startblock, which causes rec_daddr + * and next_daddr to be the same. Therefore, use the end_daddr that + * we calculated from userspace's high key to synthesize the record. + * Note that if the btree query found a mapping, there won't be a gap. + */ + if (info->last) + frec.start_daddr = info->end_daddr + 1; + else + frec.start_daddr = xfs_rtb_to_daddr(mp, start_rtb); + + frec.len_daddr = XFS_FSB_TO_BB(mp, rtbcount); + return xfs_getfsmap_helper(tp, info, &frec); +} + +/* 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) +{ + struct xfs_mount *mp = tp->t_mountp; + xfs_rtblock_t start_rtbno, end_rtbno; + xfs_rtxnum_t start_rtx, end_rtx; + xfs_rgnumber_t start_rgno, end_rgno; + struct xfs_rtgroup *rtg = NULL; + uint64_t eofs; + int error; + + eofs = XFS_FSB_TO_BB(mp, mp->m_sb.sb_rblocks); + if (keys[0].fmr_physical >= eofs) + return 0; + + info->missing_owner = XFS_FMR_OWN_UNKNOWN; + + /* Adjust the low key if we are continuing from where we left off. */ + start_rtbno = xfs_daddr_to_rtb(mp, + keys[0].fmr_physical + keys[0].fmr_length); + if (keys[0].fmr_length > 0) { + info->low_daddr = xfs_rtb_to_daddr(mp, start_rtbno); + if (info->low_daddr >= eofs) + return 0; + } + start_rtx = xfs_rtb_to_rtx(mp, start_rtbno); + start_rgno = xfs_rtb_to_rgno(mp, start_rtbno); + + end_rtbno = xfs_daddr_to_rtb(mp, min(eofs - 1, keys[1].fmr_physical)); + end_rgno = xfs_rtb_to_rgno(mp, end_rtbno); + + trace_xfs_fsmap_low_linear_key(mp, info->dev, start_rtbno); + trace_xfs_fsmap_high_linear_key(mp, info->dev, end_rtbno); + + end_rtx = -1ULL; + + while ((rtg = xfs_rtgroup_next_range(mp, rtg, start_rgno, end_rgno))) { + if (rtg_rgno(rtg) == end_rgno) + end_rtx = xfs_rtb_to_rtx(mp, + end_rtbno + mp->m_sb.sb_rextsize - 1); + + info->group = rtg_group(rtg); + xfs_rtgroup_lock(rtg, XFS_RTGLOCK_BITMAP_SHARED); + error = xfs_rtalloc_query_range(rtg, tp, start_rtx, end_rtx, + xfs_getfsmap_rtdev_rtbitmap_helper, info); + if (error) + break; + + /* + * Report any gaps at the end of the rtbitmap by simulating a + * zero-length free extent starting at the rtx after the end + * of the query range. + */ + if (rtg_rgno(rtg) == end_rgno) { + struct xfs_rtalloc_rec ahigh = { + .ar_startext = min(end_rtx + 1, + rtg->rtg_extents), + }; + + info->last = true; + error = xfs_getfsmap_rtdev_rtbitmap_helper(rtg, tp, + &ahigh, info); + if (error) + break; + } + + xfs_rtgroup_unlock(rtg, XFS_RTGLOCK_BITMAP_SHARED); + info->group = NULL; + start_rtx = 0; + } + + /* loop termination case */ + if (rtg) { + if (info->group) { + xfs_rtgroup_unlock(rtg, XFS_RTGLOCK_BITMAP_SHARED); + info->group = NULL; + } + xfs_rtgroup_rele(rtg); + } + + return error; +} + +/* Transform a realtime rmapbt record into a fsmap */ +STATIC int +xfs_getfsmap_rtdev_rmapbt_helper( + struct xfs_btree_cur *cur, + const struct xfs_rmap_irec *rec, + void *priv) +{ + struct xfs_fsmap_irec frec = { + .owner = rec->rm_owner, + .offset = rec->rm_offset, + .rm_flags = rec->rm_flags, + .rec_key = rec->rm_startblock, + }; + struct xfs_getfsmap_info *info = priv; + + return xfs_getfsmap_group_helper(info, cur->bc_tp, cur->bc_group, + rec->rm_startblock, rec->rm_blockcount, &frec); +} + +/* Actually query the rtrmap btree. */ +STATIC int +xfs_getfsmap_rtdev_rmapbt_query( + struct xfs_trans *tp, + struct xfs_getfsmap_info *info, + struct xfs_btree_cur **curpp) +{ + struct xfs_rtgroup *rtg = to_rtg(info->group); + + /* Query the rtrmapbt */ + xfs_rtgroup_lock(rtg, XFS_RTGLOCK_RMAP | XFS_RTGLOCK_REFCOUNT); + *curpp = xfs_rtrmapbt_init_cursor(tp, rtg); + return xfs_rmap_query_range(*curpp, &info->low, &info->high, + xfs_getfsmap_rtdev_rmapbt_helper, info); +} + +/* Execute a getfsmap query against the realtime device rmapbt. */ +STATIC int +xfs_getfsmap_rtdev_rmapbt( + struct xfs_trans *tp, + const struct xfs_fsmap *keys, + struct xfs_getfsmap_info *info) +{ + struct xfs_fsmap key0 = *keys; /* struct copy */ + struct xfs_mount *mp = tp->t_mountp; + struct xfs_rtgroup *rtg = NULL; + struct xfs_btree_cur *bt_cur = NULL; + xfs_daddr_t rtstart_daddr; + xfs_rtblock_t start_rtb; + xfs_rtblock_t end_rtb; + xfs_rgnumber_t start_rg, end_rg; + uint64_t eofs; + int error = 0; + + eofs = XFS_FSB_TO_BB(mp, mp->m_sb.sb_rtstart + mp->m_sb.sb_rblocks); + if (key0.fmr_physical >= eofs) + return 0; + + /* + * On zoned filesystems with an internal rt volume, the volume comes + * immediately after the end of the data volume. However, the + * xfs_rtblock_t address space is relative to the start of the data + * device, which means that the first @rtstart fsblocks do not actually + * point anywhere. If a fsmap query comes in with the low key starting + * below @rtstart, report it as "owned by filesystem". + */ + rtstart_daddr = XFS_FSB_TO_BB(mp, mp->m_sb.sb_rtstart); + if (xfs_has_zoned(mp) && key0.fmr_physical < rtstart_daddr) { + struct xfs_fsmap_irec frec = { + .owner = XFS_RMAP_OWN_FS, + .len_daddr = rtstart_daddr, + }; + + /* + * Adjust the start of the query range if we're picking up from + * a previous round, and only emit the record if we haven't + * already gone past. + */ + key0.fmr_physical += key0.fmr_length; + if (key0.fmr_physical < rtstart_daddr) { + error = xfs_getfsmap_helper(tp, info, &frec); + if (error) + return error; + + key0.fmr_physical = rtstart_daddr; + } + + /* Zero the other fields to avoid further adjustments. */ + key0.fmr_owner = 0; + key0.fmr_offset = 0; + key0.fmr_length = 0; + } + + start_rtb = xfs_daddr_to_rtb(mp, key0.fmr_physical); + end_rtb = xfs_daddr_to_rtb(mp, min(eofs - 1, keys[1].fmr_physical)); + info->missing_owner = XFS_FMR_OWN_FREE; + + /* + * Convert the fsmap low/high keys to rtgroup based keys. Initialize + * low to the fsmap low key and max out the high key to the end + * of the rtgroup. + */ + info->low.rm_offset = XFS_BB_TO_FSBT(mp, key0.fmr_offset); + error = xfs_fsmap_owner_to_rmap(&info->low, &key0); + if (error) + return error; + info->low.rm_blockcount = XFS_BB_TO_FSBT(mp, key0.fmr_length); + xfs_getfsmap_set_irec_flags(&info->low, &key0); + + /* Adjust the low key if we are continuing from where we left off. */ + if (info->low.rm_blockcount == 0) { + /* No previous record from which to continue */ + } else if (rmap_not_shareable(mp, &info->low)) { + /* Last record seen was an unshareable extent */ + info->low.rm_owner = 0; + info->low.rm_offset = 0; + + start_rtb += info->low.rm_blockcount; + if (xfs_rtb_to_daddr(mp, start_rtb) >= eofs) + return 0; + } else { + /* Last record seen was a shareable file data extent */ + info->low.rm_offset += info->low.rm_blockcount; + } + info->low.rm_startblock = xfs_rtb_to_rgbno(mp, start_rtb); + + 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_rg = xfs_rtb_to_rgno(mp, start_rtb); + end_rg = xfs_rtb_to_rgno(mp, end_rtb); + + while ((rtg = xfs_rtgroup_next_range(mp, rtg, start_rg, end_rg))) { + /* + * Set the rtgroup high key from the fsmap high key if this + * is the last rtgroup that we're querying. + */ + info->group = rtg_group(rtg); + if (rtg_rgno(rtg) == end_rg) { + info->high.rm_startblock = + xfs_rtb_to_rgbno(mp, end_rtb); + 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_rtgroup_unlock(to_rtg(bt_cur->bc_group), + XFS_RTGLOCK_RMAP | + XFS_RTGLOCK_REFCOUNT); + xfs_btree_del_cursor(bt_cur, XFS_BTREE_NOERROR); + bt_cur = NULL; + } + + trace_xfs_fsmap_low_group_key(mp, info->dev, rtg_rgno(rtg), + &info->low); + trace_xfs_fsmap_high_group_key(mp, info->dev, rtg_rgno(rtg), + &info->high); + + error = xfs_getfsmap_rtdev_rmapbt_query(tp, info, &bt_cur); + if (error) + break; + + /* + * Set the rtgroup low key to the start of the rtgroup prior to + * moving on to the next rtgroup. + */ + if (rtg_rgno(rtg) == start_rg) + memset(&info->low, 0, sizeof(info->low)); + + /* + * If this is the last rtgroup, report any gap at the end of it + * before we drop the reference to the perag when the loop + * terminates. + */ + if (rtg_rgno(rtg) == end_rg) { + info->last = true; + error = xfs_getfsmap_rtdev_rmapbt_helper(bt_cur, + &info->high, info); + if (error) + break; + } + info->group = NULL; + } + + if (bt_cur) { + xfs_rtgroup_unlock(to_rtg(bt_cur->bc_group), + XFS_RTGLOCK_RMAP | XFS_RTGLOCK_REFCOUNT); + xfs_btree_del_cursor(bt_cur, error < 0 ? XFS_BTREE_ERROR : + XFS_BTREE_NOERROR); + } + + /* loop termination case */ + if (rtg) { + info->group = NULL; + xfs_rtgroup_rele(rtg); + } + + return error; +} +#endif /* CONFIG_XFS_RT */ + +static uint32_t +xfs_getfsmap_device( + struct xfs_mount *mp, + enum xfs_device dev) +{ + if (mp->m_sb.sb_rtstart) + return dev; + + switch (dev) { + case XFS_DEV_DATA: + return new_encode_dev(mp->m_ddev_targp->bt_dev); + case XFS_DEV_LOG: + return new_encode_dev(mp->m_logdev_targp->bt_dev); + case XFS_DEV_RT: + if (!mp->m_rtdev_targp) + break; + return new_encode_dev(mp->m_rtdev_targp->bt_dev); + } + + return -1; +} + +/* Do we recognize the device? */ +STATIC bool +xfs_getfsmap_is_valid_device( + struct xfs_mount *mp, + struct xfs_fsmap *fm) +{ + return fm->fmr_device == 0 || + fm->fmr_device == UINT_MAX || + fm->fmr_device == xfs_getfsmap_device(mp, XFS_DEV_DATA) || + fm->fmr_device == xfs_getfsmap_device(mp, XFS_DEV_LOG) || + (mp->m_rtdev_targp && + fm->fmr_device == xfs_getfsmap_device(mp, XFS_DEV_RT)); +} + +/* 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_flags & (FMR_OF_SPECIAL_OWNER | FMR_OF_EXTENT_MAP)) { + if (low_key->fmr_offset) + return false; + } + if (high_key->fmr_flags != -1U && + (high_key->fmr_flags & (FMR_OF_SPECIAL_OWNER | + FMR_OF_EXTENT_MAP))) { + if (high_key->fmr_offset && high_key->fmr_offset != -1ULL) + return false; + } + if (high_key->fmr_length && high_key->fmr_length != -1ULL) + return false; + + 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. + */ +STATIC 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 = { + .fsmap_recs = fsmap_recs, + .head = head, + }; + 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; + if (!xfs_getfsmap_check_keys(&head->fmh_keys[0], &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].nr_sectors = XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks); + handlers[0].dev = xfs_getfsmap_device(mp, XFS_DEV_DATA); + 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].nr_sectors = XFS_FSB_TO_BB(mp, + mp->m_sb.sb_logblocks); + handlers[1].dev = xfs_getfsmap_device(mp, XFS_DEV_LOG); + handlers[1].fn = xfs_getfsmap_logdev; + } +#ifdef CONFIG_XFS_RT + /* + * For zoned file systems there is no rtbitmap, so only support fsmap + * if the callers is privileged enough to use the full rmap version. + */ + if (mp->m_rtdev_targp && (use_rmap || !xfs_has_zoned(mp))) { + handlers[2].nr_sectors = XFS_FSB_TO_BB(mp, mp->m_sb.sb_rblocks); + handlers[2].dev = xfs_getfsmap_device(mp, XFS_DEV_RT); + if (use_rmap) + handlers[2].fn = xfs_getfsmap_rtdev_rmapbt; + else + 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, each fsmap backend bumps + * the file offset to continue the search appropriately. For + * all other low key mapping types (attr blocks, metadata), each + * fsmap backend bumps the physical offset as there can be no + * other mapping for the same physical block range. + */ + dkeys[0] = head->fmh_keys[0]; + memset(&dkeys[1], 0xFF, sizeof(struct xfs_fsmap)); + + info.next_daddr = head->fmh_keys[0].fmr_physical + + head->fmh_keys[0].fmr_length; + + /* 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, and + * set the end_daddr so that we can synthesize records at the + * end of the query range or device. + */ + if (handlers[i].dev == head->fmh_keys[1].fmr_device) { + dkeys[1] = head->fmh_keys[1]; + info.end_daddr = min(handlers[i].nr_sectors - 1, + dkeys[1].fmr_physical); + } else { + info.end_daddr = handlers[i].nr_sectors - 1; + } + + /* + * 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[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. + */ + tp = xfs_trans_alloc_empty(mp); + + info.dev = handlers[i].dev; + info.last = false; + info.group = NULL; + info.low_daddr = XFS_BUF_DADDR_NULL; + info.low.rm_blockcount = 0; + 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); + + /* + * For internal RT device we need to report different synthetic devices + * for a single physical device, and thus can't report the actual dev_t. + */ + if (!mp->m_sb.sb_rtstart) + head->fmh_oflags = FMH_OF_DEV_T; + return error; +} + +int +xfs_ioc_getfsmap( + struct xfs_inode *ip, + struct fsmap_head __user *arg) +{ + struct xfs_fsmap_head xhead = {0}; + struct fsmap_head head; + struct fsmap *recs; + unsigned int count; + __u32 last_flags = 0; + bool done = false; + int error; + + if (copy_from_user(&head, arg, sizeof(struct fsmap_head))) + return -EFAULT; + if (memchr_inv(head.fmh_reserved, 0, sizeof(head.fmh_reserved)) || + memchr_inv(head.fmh_keys[0].fmr_reserved, 0, + sizeof(head.fmh_keys[0].fmr_reserved)) || + memchr_inv(head.fmh_keys[1].fmr_reserved, 0, + sizeof(head.fmh_keys[1].fmr_reserved))) + return -EINVAL; + + /* + * Use an internal memory buffer so that we don't have to copy fsmap + * data to userspace while holding locks. Start by trying to allocate + * up to 128k for the buffer, but fall back to a single page if needed. + */ + count = min_t(unsigned int, head.fmh_count, + 131072 / sizeof(struct fsmap)); + recs = kvcalloc(count, sizeof(struct fsmap), GFP_KERNEL); + if (!recs) { + count = min_t(unsigned int, head.fmh_count, + PAGE_SIZE / sizeof(struct fsmap)); + recs = kvcalloc(count, sizeof(struct fsmap), GFP_KERNEL); + if (!recs) + return -ENOMEM; + } + + xhead.fmh_iflags = head.fmh_iflags; + xfs_fsmap_to_internal(&xhead.fmh_keys[0], &head.fmh_keys[0]); + xfs_fsmap_to_internal(&xhead.fmh_keys[1], &head.fmh_keys[1]); + + trace_xfs_getfsmap_low_key(ip->i_mount, &xhead.fmh_keys[0]); + trace_xfs_getfsmap_high_key(ip->i_mount, &xhead.fmh_keys[1]); + + head.fmh_entries = 0; + do { + struct fsmap __user *user_recs; + struct fsmap *last_rec; + + user_recs = &arg->fmh_recs[head.fmh_entries]; + xhead.fmh_entries = 0; + xhead.fmh_count = min_t(unsigned int, count, + head.fmh_count - head.fmh_entries); + + /* Run query, record how many entries we got. */ + error = xfs_getfsmap(ip->i_mount, &xhead, recs); + switch (error) { + case 0: + /* + * There are no more records in the result set. Copy + * whatever we got to userspace and break out. + */ + done = true; + break; + case -ECANCELED: + /* + * The internal memory buffer is full. Copy whatever + * records we got to userspace and go again if we have + * not yet filled the userspace buffer. + */ + error = 0; + break; + default: + goto out_free; + } + head.fmh_entries += xhead.fmh_entries; + head.fmh_oflags = xhead.fmh_oflags; + + /* + * If the caller wanted a record count or there aren't any + * new records to return, we're done. + */ + if (head.fmh_count == 0 || xhead.fmh_entries == 0) + break; + + /* Copy all the records we got out to userspace. */ + if (copy_to_user(user_recs, recs, + xhead.fmh_entries * sizeof(struct fsmap))) { + error = -EFAULT; + goto out_free; + } + + /* Remember the last record flags we copied to userspace. */ + last_rec = &recs[xhead.fmh_entries - 1]; + last_flags = last_rec->fmr_flags; + + /* Set up the low key for the next iteration. */ + xfs_fsmap_to_internal(&xhead.fmh_keys[0], last_rec); + trace_xfs_getfsmap_low_key(ip->i_mount, &xhead.fmh_keys[0]); + } while (!done && head.fmh_entries < head.fmh_count); + + /* + * If there are no more records in the query result set and we're not + * in counting mode, mark the last record returned with the LAST flag. + */ + if (done && head.fmh_count > 0 && head.fmh_entries > 0) { + struct fsmap __user *user_rec; + + last_flags |= FMR_OF_LAST; + user_rec = &arg->fmh_recs[head.fmh_entries - 1]; + + if (copy_to_user(&user_rec->fmr_flags, &last_flags, + sizeof(last_flags))) { + error = -EFAULT; + goto out_free; + } + } + + /* copy back header */ + if (copy_to_user(arg, &head, sizeof(struct fsmap_head))) { + error = -EFAULT; + goto out_free; + } + +out_free: + kvfree(recs); + return error; +} |