3 files changed, 46 insertions, 24 deletions

diff --git a/fs/xfs/xfs_alloc.c b/fs/xfs/xfs_alloc.c
index 31e90335b83d..0f0df2759b09 100644
--- a/fs/xfs/xfs_alloc.c
+++ b/fs/xfs/xfs_alloc.c
@@ -69,7 +69,7 @@ xfs_alloc_lookup_eq(
  * Lookup the first record greater than or equal to [bno, len]
  * in the btree given by cur.
  */
-STATIC int                              /* error */
+int                             /* error */
 xfs_alloc_lookup_ge(
         struct xfs_btree_cur    *cur,   /* btree cursor */
         xfs_agblock_t           bno,    /* starting block of extent */
diff --git a/fs/xfs/xfs_alloc.h b/fs/xfs/xfs_alloc.h
index ab5d0fd2f535..3a7e7d8f8ded 100644
--- a/fs/xfs/xfs_alloc.h
+++ b/fs/xfs/xfs_alloc.h
@@ -248,6 +248,13 @@ xfs_alloc_lookup_le(
         xfs_extlen_t            len,    /* length of extent */
         int                     *stat); /* success/failure */
 
+int                             /* error */
+xfs_alloc_lookup_ge(
+        struct xfs_btree_cur    *cur,   /* btree cursor */
+        xfs_agblock_t           bno,    /* starting block of extent */
+        xfs_extlen_t            len,    /* length of extent */
+        int                     *stat); /* success/failure */
+
 int                                     /* error */
 xfs_alloc_get_rec(
         struct xfs_btree_cur    *cur,   /* btree cursor */
diff --git a/fs/xfs/xfs_discard.c b/fs/xfs/xfs_discard.c
index 286a051f12cf..1ad3a4b8ca40 100644
--- a/fs/xfs/xfs_discard.c
+++ b/fs/xfs/xfs_discard.c
@@ -37,9 +37,9 @@ STATIC int
 xfs_trim_extents(
         struct xfs_mount        *mp,
         xfs_agnumber_t          agno,
-        xfs_fsblock_t           start,
-        xfs_fsblock_t           end,
-        xfs_fsblock_t           minlen,
+        xfs_daddr_t             start,
+        xfs_daddr_t             end,
+        xfs_daddr_t             minlen,
         __uint64_t              *blocks_trimmed)
 {
         struct block_device     *bdev = mp->m_ddev_targp->bt_bdev;
@@ -67,7 +67,7 @@ xfs_trim_extents(
         /*
          * Look up the longest btree in the AGF and start with it.
          */
-        error = xfs_alloc_lookup_le(cur, 0,
+        error = xfs_alloc_lookup_ge(cur, 0,
                             be32_to_cpu(XFS_BUF_TO_AGF(agbp)->agf_longest), &i);
         if (error)
                 goto out_del_cursor;
@@ -77,8 +77,10 @@ xfs_trim_extents(
          * enough to be worth discarding.
          */
         while (i) {
-                xfs_agblock_t fbno;
-                xfs_extlen_t flen;
+                xfs_agblock_t   fbno;
+                xfs_extlen_t    flen;
+                xfs_daddr_t     dbno;
+                xfs_extlen_t    dlen;
 
                 error = xfs_alloc_get_rec(cur, &fbno, &flen, &i);
                 if (error)
@@ -87,9 +89,17 @@ xfs_trim_extents(
                 ASSERT(flen <= be32_to_cpu(XFS_BUF_TO_AGF(agbp)->agf_longest));
 
                 /*
+                 * use daddr format for all range/len calculations as that is
+                 * the format the range/len variables are supplied in by
+                 * userspace.
+                 */
+                dbno = XFS_AGB_TO_DADDR(mp, agno, fbno);
+                dlen = XFS_FSB_TO_BB(mp, flen);
+
+                /*
                  * Too small?  Give up.
                  */
-                if (flen < minlen) {
+                if (dlen < minlen) {
                         trace_xfs_discard_toosmall(mp, agno, fbno, flen);
                         goto out_del_cursor;
                 }
@@ -99,8 +109,7 @@ xfs_trim_extents(
                  * supposed to discard skip it.  Do not bother to trim
                  * down partially overlapping ranges for now.
                  */
-                if (XFS_AGB_TO_FSB(mp, agno, fbno) + flen < start ||
-                    XFS_AGB_TO_FSB(mp, agno, fbno) > end) {
+                if (dbno + dlen < start || dbno > end) {
                         trace_xfs_discard_exclude(mp, agno, fbno, flen);
                         goto next_extent;
                 }
@@ -115,10 +124,7 @@ xfs_trim_extents(
                 }
 
                 trace_xfs_discard_extent(mp, agno, fbno, flen);
-                error = -blkdev_issue_discard(bdev,
-                                XFS_AGB_TO_DADDR(mp, agno, fbno),
-                                XFS_FSB_TO_BB(mp, flen),
-                                GFP_NOFS, 0);
+                error = -blkdev_issue_discard(bdev, dbno, dlen, GFP_NOFS, 0);
                 if (error)
                         goto out_del_cursor;
                 *blocks_trimmed += flen;
@@ -137,6 +143,15 @@ out_put_perag:
         return error;
 }
 
+/*
+ * trim a range of the filesystem.
+ *
+ * Note: the parameters passed from userspace are byte ranges into the
+ * filesystem which does not match to the format we use for filesystem block
+ * addressing. FSB addressing is sparse (AGNO|AGBNO), while the incoming format
+ * is a linear address range. Hence we need to use DADDR based conversions and
+ * comparisons for determining the correct offset and regions to trim.
+ */
 int
 xfs_ioc_trim(
         struct xfs_mount                *mp,
@@ -145,7 +160,7 @@ xfs_ioc_trim(
         struct request_queue    *q = mp->m_ddev_targp->bt_bdev->bd_disk->queue;
         unsigned int            granularity = q->limits.discard_granularity;
         struct fstrim_range     range;
-        xfs_fsblock_t           start, end, minlen;
+        xfs_daddr_t             start, end, minlen;
         xfs_agnumber_t          start_agno, end_agno, agno;
         __uint64_t              blocks_trimmed = 0;
         int                     error, last_error = 0;
@@ -159,22 +174,22 @@ xfs_ioc_trim(
 
         /*
          * Truncating down the len isn't actually quite correct, but using
-         * XFS_B_TO_FSB would mean we trivially get overflows for values
+         * BBTOB would mean we trivially get overflows for values
          * of ULLONG_MAX or slightly lower.  And ULLONG_MAX is the default
          * used by the fstrim application.  In the end it really doesn't
          * matter as trimming blocks is an advisory interface.
          */
-        start = XFS_B_TO_FSBT(mp, range.start);
-        end = start + XFS_B_TO_FSBT(mp, range.len) - 1;
-        minlen = XFS_B_TO_FSB(mp, max_t(u64, granularity, range.minlen));
+        start = BTOBB(range.start);
+        end = start + BTOBBT(range.len) - 1;
+        minlen = BTOBB(max_t(u64, granularity, range.minlen));
 
-        if (start >= mp->m_sb.sb_dblocks)
+        if (XFS_BB_TO_FSB(mp, start) >= mp->m_sb.sb_dblocks)
                 return -XFS_ERROR(EINVAL);
-        if (end > mp->m_sb.sb_dblocks - 1)
-                end = mp->m_sb.sb_dblocks - 1;
+        if (end > XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks) - 1)
+                end = XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks)- 1;
 
-        start_agno = XFS_FSB_TO_AGNO(mp, start);
-        end_agno = XFS_FSB_TO_AGNO(mp, end);
+        start_agno = xfs_daddr_to_agno(mp, start);
+        end_agno = xfs_daddr_to_agno(mp, end);
 
         for (agno = start_agno; agno <= end_agno; agno++) {
                 error = -xfs_trim_extents(mp, agno, start, end, minlen,