summaryrefslogtreecommitdiffstats
path: root/fs/xfs/xfs_fsmap.c
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /fs/xfs/xfs_fsmap.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'fs/xfs/xfs_fsmap.c')
-rw-r--r--fs/xfs/xfs_fsmap.c1003
1 files changed, 1003 insertions, 0 deletions
diff --git a/fs/xfs/xfs_fsmap.c b/fs/xfs/xfs_fsmap.c
new file mode 100644
index 0000000000..736e5545f5
--- /dev/null
+++ b/fs/xfs/xfs_fsmap.c
@@ -0,0 +1,1003 @@
+// 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 */
+ /* daddr of low fsmap key when we're using the rtbitmap */
+ xfs_daddr_t low_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);
+};
+
+/* 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);
+}
+
+static inline bool
+xfs_getfsmap_rec_before_start(
+ struct xfs_getfsmap_info *info,
+ const struct xfs_rmap_irec *rec,
+ xfs_daddr_t rec_daddr)
+{
+ if (info->low_daddr != -1ULL)
+ return rec_daddr < info->low_daddr;
+ if (info->low.rm_blockcount)
+ 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_rmap_irec *rec,
+ xfs_daddr_t rec_daddr,
+ xfs_daddr_t len_daddr)
+{
+ struct xfs_fsmap fmr;
+ struct xfs_mount *mp = tp->t_mountp;
+ bool shared;
+ int error;
+
+ if (fatal_signal_pending(current))
+ return -EINTR;
+
+ if (len_daddr == 0)
+ len_daddr = XFS_FSB_TO_BB(mp, rec->rm_blockcount);
+
+ /*
+ * Filter out records that start before our startpoint, if the
+ * caller requested that.
+ */
+ if (xfs_getfsmap_rec_before_start(info, rec, rec_daddr)) {
+ rec_daddr += len_daddr;
+ 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 += len_daddr;
+ 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 = len_daddr;
+ 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 += len_daddr;
+ 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, 0);
+}
+
+/* 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, 0);
+}
+
+/* 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;
+ xfs_daddr_t rec_daddr, len_daddr;
+ 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_key_linear(mp, info->dev, start_fsb);
+ trace_xfs_fsmap_high_key_linear(mp, info->dev, end_fsb);
+
+ if (start_fsb > 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;
+
+ rec_daddr = XFS_FSB_TO_BB(mp, rmap.rm_startblock);
+ len_daddr = XFS_FSB_TO_BB(mp, rmap.rm_blockcount);
+ return xfs_getfsmap_helper(tp, info, &rmap, rec_daddr, len_daddr);
+}
+
+#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_rtblock_t rtbno;
+ xfs_daddr_t rec_daddr, len_daddr;
+
+ rtbno = rec->ar_startext * mp->m_sb.sb_rextsize;
+ rec_daddr = XFS_FSB_TO_BB(mp, rtbno);
+ irec.rm_startblock = rtbno;
+
+ rtbno = rec->ar_extcount * mp->m_sb.sb_rextsize;
+ len_daddr = XFS_FSB_TO_BB(mp, rtbno);
+ irec.rm_blockcount = rtbno;
+
+ 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, len_daddr);
+}
+
+/* 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_rtalloc_rec alow = { 0 };
+ struct xfs_rtalloc_rec ahigh = { 0 };
+ struct xfs_mount *mp = tp->t_mountp;
+ xfs_rtblock_t start_rtb;
+ xfs_rtblock_t end_rtb;
+ uint64_t eofs;
+ int error;
+
+ eofs = XFS_FSB_TO_BB(mp, mp->m_sb.sb_rextents * mp->m_sb.sb_rextsize);
+ if (keys[0].fmr_physical >= eofs)
+ return 0;
+ start_rtb = XFS_BB_TO_FSBT(mp,
+ keys[0].fmr_physical + keys[0].fmr_length);
+ end_rtb = XFS_BB_TO_FSB(mp, min(eofs - 1, keys[1].fmr_physical));
+
+ info->missing_owner = XFS_FMR_OWN_UNKNOWN;
+
+ /* 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_rtb);
+ if (info->low_daddr >= eofs)
+ return 0;
+ }
+
+ trace_xfs_fsmap_low_key_linear(mp, info->dev, start_rtb);
+ trace_xfs_fsmap_high_key_linear(mp, info->dev, end_rtb);
+
+ xfs_ilock(mp->m_rbmip, XFS_ILOCK_SHARED | XFS_ILOCK_RTBITMAP);
+
+ /*
+ * Set up query parameters to return free rtextents covering the range
+ * we want.
+ */
+ alow.ar_startext = start_rtb;
+ ahigh.ar_startext = end_rtb;
+ 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 | XFS_ILOCK_RTBITMAP);
+ return error;
+}
+#endif /* CONFIG_XFS_RT */
+
+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;
+ 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_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);
+
+ 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)
+ 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->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_rele(info->pag);
+ info->pag = 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_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];
+
+ 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]);
+}
+
+/* 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_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.
+ */
+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;
+ 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].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, 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;
+ 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;
+ info.low_daddr = -1ULL;
+ 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);
+ head->fmh_oflags = FMH_OF_DEV_T;
+ return error;
+}