[PATCH 17/37] xfs: wire up getfsmap to the realtime reverse mapping btree

Darrick J. Wong
2024-12-13T01:05:01Z

From: Darrick J. Wong <djwong@kernel.org>

Connect the getfsmap ioctl to the realtime rmapbt.

Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
---
fs/xfs/xfs_fsmap.c | 174 ++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 173 insertions(+), 1 deletion(-)

diff --git a/fs/xfs/xfs_fsmap.c b/fs/xfs/xfs_fsmap.c
index 3290dd8524a69a..3e3ef16f65a335 100644
--- a/fs/xfs/xfs_fsmap.c
+++ b/fs/xfs/xfs_fsmap.c
@@ -26,6 +26,7 @@
#include "xfs_rtbitmap.h"
#include "xfs_ag.h"
#include "xfs_rtgroup.h"
+#include "xfs_rtrmap_btree.h"

/* Convert an xfs_fsmap to an fsmap. */
static void
@@ -832,6 +833,174 @@ xfs_getfsmap_rtdev_rtbitmap(

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);
+ *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_mount *mp = tp->t_mountp;
+ struct xfs_rtgroup *rtg = NULL;
+ struct xfs_btree_cur *bt_cur = NULL;
+ 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_rblocks);
+ if (keys[0].fmr_physical >= eofs)
+ return 0;
+ start_rtb = xfs_daddr_to_rtb(mp, keys[0].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, 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_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_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_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 */

/* Do we recognize the device? */
@@ -971,7 +1140,10 @@ xfs_getfsmap(
if (mp->m_rtdev_targp) {
handlers[2].nr_sectors = XFS_FSB_TO_BB(mp, mp->m_sb.sb_rblocks);
handlers[2].dev = new_encode_dev(mp->m_rtdev_targp->bt_dev);
- handlers[2].fn = xfs_getfsmap_rtdev_rtbitmap;
+ if (use_rmap)
+ handlers[2].fn = xfs_getfsmap_rtdev_rmapbt;
+ else
+ handlers[2].fn = xfs_getfsmap_rtdev_rtbitmap;
}
#endif /* CONFIG_XFS_RT */