Merge branch 'xfs-4.10-extent-lookup' into for-next

9 files changed, 178 insertions, 267 deletions

diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index 5c3c4dd14735..4a5b335c7bb3 100644
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -1370,97 +1370,6 @@ error0:
         return -EFSCORRUPTED;
 }
 
-
-/*
- * Search the extent records for the entry containing block bno.
- * If bno lies in a hole, point to the next entry.  If bno lies
- * past eof, *eofp will be set, and *prevp will contain the last
- * entry (null if none).  Else, *lastxp will be set to the index
- * of the found entry; *gotp will contain the entry.
- */
-STATIC xfs_bmbt_rec_host_t *            /* pointer to found extent entry */
-xfs_bmap_search_multi_extents(
-        xfs_ifork_t     *ifp,           /* inode fork pointer */
-        xfs_fileoff_t   bno,            /* block number searched for */
-        int             *eofp,          /* out: end of file found */
-        xfs_extnum_t    *lastxp,        /* out: last extent index */
-        xfs_bmbt_irec_t *gotp,          /* out: extent entry found */
-        xfs_bmbt_irec_t *prevp)         /* out: previous extent entry found */
-{
-        xfs_bmbt_rec_host_t *ep;                /* extent record pointer */
-        xfs_extnum_t    lastx;          /* last extent index */
-
-        /*
-         * Initialize the extent entry structure to catch access to
-         * uninitialized br_startblock field.
-         */
-        gotp->br_startoff = 0xffa5a5a5a5a5a5a5LL;
-        gotp->br_blockcount = 0xa55a5a5a5a5a5a5aLL;
-        gotp->br_state = XFS_EXT_INVALID;
-        gotp->br_startblock = 0xffffa5a5a5a5a5a5LL;
-        prevp->br_startoff = NULLFILEOFF;
-
-        ep = xfs_iext_bno_to_ext(ifp, bno, &lastx);
-        if (lastx > 0) {
-                xfs_bmbt_get_all(xfs_iext_get_ext(ifp, lastx - 1), prevp);
-        }
-        if (lastx < xfs_iext_count(ifp)) {
-                xfs_bmbt_get_all(ep, gotp);
-                *eofp = 0;
-        } else {
-                if (lastx > 0) {
-                        *gotp = *prevp;
-                }
-                *eofp = 1;
-                ep = NULL;
-        }
-        *lastxp = lastx;
-        return ep;
-}
-
-/*
- * Search the extents list for the inode, for the extent containing bno.
- * If bno lies in a hole, point to the next entry.  If bno lies past eof,
- * *eofp will be set, and *prevp will contain the last entry (null if none).
- * Else, *lastxp will be set to the index of the found
- * entry; *gotp will contain the entry.
- */
-xfs_bmbt_rec_host_t *                 /* pointer to found extent entry */
-xfs_bmap_search_extents(
-        xfs_inode_t     *ip,            /* incore inode pointer */
-        xfs_fileoff_t   bno,            /* block number searched for */
-        int             fork,           /* data or attr fork */
-        int             *eofp,          /* out: end of file found */
-        xfs_extnum_t    *lastxp,        /* out: last extent index */
-        xfs_bmbt_irec_t *gotp,          /* out: extent entry found */
-        xfs_bmbt_irec_t *prevp)         /* out: previous extent entry found */
-{
-        xfs_ifork_t     *ifp;           /* inode fork pointer */
-        xfs_bmbt_rec_host_t  *ep;            /* extent record pointer */
-
-        XFS_STATS_INC(ip->i_mount, xs_look_exlist);
-        ifp = XFS_IFORK_PTR(ip, fork);
-
-        ep = xfs_bmap_search_multi_extents(ifp, bno, eofp, lastxp, gotp, prevp);
-
-        if (unlikely(!(gotp->br_startblock) && (*lastxp != NULLEXTNUM) &&
-                     !(XFS_IS_REALTIME_INODE(ip) && fork == XFS_DATA_FORK))) {
-                xfs_alert_tag(ip->i_mount, XFS_PTAG_FSBLOCK_ZERO,
-                                "Access to block zero in inode %llu "
-                                "start_block: %llx start_off: %llx "
-                                "blkcnt: %llx extent-state: %x lastx: %x",
-                        (unsigned long long)ip->i_ino,
-                        (unsigned long long)gotp->br_startblock,
-                        (unsigned long long)gotp->br_startoff,
-                        (unsigned long long)gotp->br_blockcount,
-                        gotp->br_state, *lastxp);
-                *lastxp = NULLEXTNUM;
-                *eofp = 1;
-                return NULL;
-        }
-        return ep;
-}
-
 /*
  * Returns the file-relative block number of the first unused block(s)
  * in the file with at least "len" logically contiguous blocks free.
@@ -1523,44 +1432,44 @@ xfs_bmap_first_unused(
  */
 int                                             /* error */
 xfs_bmap_last_before(
-        xfs_trans_t     *tp,                    /* transaction pointer */
-        xfs_inode_t     *ip,                    /* incore inode */
-        xfs_fileoff_t   *last_block,            /* last block */
-        int             whichfork)              /* data or attr fork */
+        struct xfs_trans        *tp,            /* transaction pointer */
+        struct xfs_inode        *ip,            /* incore inode */
+        xfs_fileoff_t           *last_block,    /* last block */
+        int                     whichfork)      /* data or attr fork */
 {
-        xfs_fileoff_t   bno;                    /* input file offset */
-        int             eof;                    /* hit end of file */
-        xfs_bmbt_rec_host_t *ep;                /* pointer to last extent */
-        int             error;                  /* error return value */
-        xfs_bmbt_irec_t got;                    /* current extent value */
-        xfs_ifork_t     *ifp;                   /* inode fork pointer */
-        xfs_extnum_t    lastx;                  /* last extent used */
-        xfs_bmbt_irec_t prev;                   /* previous extent value */
+        struct xfs_ifork        *ifp = XFS_IFORK_PTR(ip, whichfork);
+        struct xfs_bmbt_irec    got;
+        xfs_extnum_t            idx;
+        int                     error;
 
-        if (XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_BTREE &&
-            XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_EXTENTS &&
-            XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_LOCAL)
-               return -EIO;
-        if (XFS_IFORK_FORMAT(ip, whichfork) == XFS_DINODE_FMT_LOCAL) {
+        switch (XFS_IFORK_FORMAT(ip, whichfork)) {
+        case XFS_DINODE_FMT_LOCAL:
                 *last_block = 0;
                 return 0;
+        case XFS_DINODE_FMT_BTREE:
+        case XFS_DINODE_FMT_EXTENTS:
+                break;
+        default:
+                return -EIO;
         }
-        ifp = XFS_IFORK_PTR(ip, whichfork);
-        if (!(ifp->if_flags & XFS_IFEXTENTS) &&
-            (error = xfs_iread_extents(tp, ip, whichfork)))
-                return error;
-        bno = *last_block - 1;
-        ep = xfs_bmap_search_extents(ip, bno, whichfork, &eof, &lastx, &got,
-                &prev);
-        if (eof || xfs_bmbt_get_startoff(ep) > bno) {
-                if (prev.br_startoff == NULLFILEOFF)
-                        *last_block = 0;
-                else
-                        *last_block = prev.br_startoff + prev.br_blockcount;
+
+        if (!(ifp->if_flags & XFS_IFEXTENTS)) {
+                error = xfs_iread_extents(tp, ip, whichfork);
+                if (error)
+                        return error;
         }
-        /*
-         * Otherwise *last_block is already the right answer.
-         */
+
+        if (xfs_iext_lookup_extent(ip, ifp, *last_block - 1, &idx, &got)) {
+                if (got.br_startoff <= *last_block - 1)
+                        return 0;
+        }
+
+        if (xfs_iext_get_extent(ifp, idx - 1, &got)) {
+                *last_block = got.br_startoff + got.br_blockcount;
+                return 0;
+        }
+
+        *last_block = 0;
         return 0;
 }
 
@@ -4145,12 +4054,11 @@ xfs_bmapi_read(
         struct xfs_mount        *mp = ip->i_mount;
         struct xfs_ifork        *ifp;
         struct xfs_bmbt_irec    got;
-        struct xfs_bmbt_irec    prev;
         xfs_fileoff_t           obno;
         xfs_fileoff_t           end;
-        xfs_extnum_t            lastx;
+        xfs_extnum_t            idx;
         int                     error;
-        int                     eof;
+        bool                    eof = false;
         int                     n = 0;
         int                     whichfork = xfs_bmapi_whichfork(flags);
 
@@ -4190,7 +4098,8 @@ xfs_bmapi_read(
                         return error;
         }
 
-        xfs_bmap_search_extents(ip, bno, whichfork, &eof, &lastx, &got, &prev);
+        if (!xfs_iext_lookup_extent(ip, ifp, bno, &idx, &got))
+                eof = true;
         end = bno + len;
         obno = bno;
 
@@ -4221,10 +4130,8 @@ xfs_bmapi_read(
                         break;
 
                 /* Else go on to the next record. */
-                if (++lastx < xfs_iext_count(ifp))
-                        xfs_bmbt_get_all(xfs_iext_get_ext(ifp, lastx), &got);
-                else
-                        eof = 1;
+                if (!xfs_iext_get_extent(ifp, ++idx, &got))
+                        eof = true;
         }
         *nmap = n;
         return 0;
@@ -4237,7 +4144,6 @@ xfs_bmapi_reserve_delalloc(
         xfs_fileoff_t           aoff,
         xfs_filblks_t           len,
         struct xfs_bmbt_irec    *got,
-        struct xfs_bmbt_irec    *prev,
         xfs_extnum_t            *lastx,
         int                     eof)
 {
@@ -4259,7 +4165,12 @@ xfs_bmapi_reserve_delalloc(
         else
                 extsz = xfs_get_extsz_hint(ip);
         if (extsz) {
-                error = xfs_bmap_extsize_align(mp, got, prev, extsz, rt, eof,
+                struct xfs_bmbt_irec    prev;
+
+                if (!xfs_iext_get_extent(ifp, *lastx - 1, &prev))
+                        prev.br_startoff = NULLFILEOFF;
+
+                error = xfs_bmap_extsize_align(mp, got, &prev, extsz, rt, eof,
                                                1, 0, &aoff, &alen);
                 ASSERT(!error);
         }
@@ -4349,7 +4260,7 @@ xfs_bmapi_allocate(
         if (bma->wasdel) {
                 bma->length = (xfs_extlen_t)bma->got.br_blockcount;
                 bma->offset = bma->got.br_startoff;
-                if (bma->idx != NULLEXTNUM && bma->idx) {
+                if (bma->idx) {
                         xfs_bmbt_get_all(xfs_iext_get_ext(ifp, bma->idx - 1),
                                          &bma->prev);
                 }
@@ -4563,7 +4474,7 @@ xfs_bmapi_write(
         struct xfs_ifork        *ifp;
         struct xfs_bmalloca     bma = { NULL }; /* args for xfs_bmap_alloc */
         xfs_fileoff_t           end;            /* end of mapped file region */
-        int                     eof;            /* after the end of extents */
+        bool                    eof = false;    /* after the end of extents */
         int                     error;          /* error return */
         int                     n;              /* current extent index */
         xfs_fileoff_t           obno;           /* old block number (offset) */
@@ -4641,12 +4552,14 @@ xfs_bmapi_write(
                         goto error0;
         }
 
-        xfs_bmap_search_extents(ip, bno, whichfork, &eof, &bma.idx, &bma.got,
-                                &bma.prev);
         n = 0;
         end = bno + len;
         obno = bno;
 
+        if (!xfs_iext_lookup_extent(ip, ifp, bno, &bma.idx, &bma.got))
+                eof = true;
+        if (!xfs_iext_get_extent(ifp, bma.idx - 1, &bma.prev))
+                bma.prev.br_startoff = NULLFILEOFF;
         bma.tp = tp;
         bma.ip = ip;
         bma.total = total;
@@ -4733,11 +4646,8 @@ xfs_bmapi_write(
 
                 /* Else go on to the next record. */
                 bma.prev = bma.got;
-                if (++bma.idx < xfs_iext_count(ifp)) {
-                        xfs_bmbt_get_all(xfs_iext_get_ext(ifp, bma.idx),
-                                         &bma.got);
-                } else
-                        eof = 1;
+                if (!xfs_iext_get_extent(ifp, ++bma.idx, &bma.got))
+                        eof = true;
         }
         *nmap = n;
 
@@ -5436,8 +5346,6 @@ __xfs_bunmapi(
 {
         xfs_btree_cur_t         *cur;           /* bmap btree cursor */
         xfs_bmbt_irec_t         del;            /* extent being deleted */
-        int                     eof;            /* is deleting at eof */
-        xfs_bmbt_rec_host_t     *ep;            /* extent record pointer */
         int                     error;          /* error return value */
         xfs_extnum_t            extno;          /* extent number in list */
         xfs_bmbt_irec_t         got;            /* current extent record */
@@ -5447,7 +5355,6 @@ __xfs_bunmapi(
         int                     logflags;       /* transaction logging flags */
         xfs_extlen_t            mod;            /* rt extent offset */
         xfs_mount_t             *mp;            /* mount structure */
-        xfs_bmbt_irec_t         prev;           /* previous extent record */
         xfs_fileoff_t           start;          /* first file offset deleted */
         int                     tmp_logflags;   /* partial logging flags */
         int                     wasdel;         /* was a delayed alloc extent */
@@ -5486,18 +5393,17 @@ __xfs_bunmapi(
         isrt = (whichfork == XFS_DATA_FORK) && XFS_IS_REALTIME_INODE(ip);
         start = bno;
         bno = start + len - 1;
-        ep = xfs_bmap_search_extents(ip, bno, whichfork, &eof, &lastx, &got,
-                &prev);
 
         /*
          * Check to see if the given block number is past the end of the
          * file, back up to the last block if so...
          */
-        if (eof) {
-                ep = xfs_iext_get_ext(ifp, --lastx);
-                xfs_bmbt_get_all(ep, &got);
+        if (!xfs_iext_lookup_extent(ip, ifp, bno, &lastx, &got)) {
+                ASSERT(lastx > 0);
+                xfs_iext_get_extent(ifp, --lastx, &got);
                 bno = got.br_startoff + got.br_blockcount - 1;
         }
+
         logflags = 0;
         if (ifp->if_flags & XFS_IFBROOT) {
                 ASSERT(XFS_IFORK_FORMAT(ip, whichfork) == XFS_DINODE_FMT_BTREE);
@@ -5528,8 +5434,7 @@ __xfs_bunmapi(
                 if (got.br_startoff > bno) {
                         if (--lastx < 0)
                                 break;
-                        ep = xfs_iext_get_ext(ifp, lastx);
-                        xfs_bmbt_get_all(ep, &got);
+                        xfs_iext_get_extent(ifp, lastx, &got);
                 }
                 /*
                  * Is the last block of this extent before the range
@@ -5543,7 +5448,6 @@ __xfs_bunmapi(
                  * Then deal with the (possibly delayed) allocated space
                  * we found.
                  */
-                ASSERT(ep != NULL);
                 del = got;
                 wasdel = isnullstartblock(del.br_startblock);
                 if (got.br_startoff < start) {
@@ -5624,15 +5528,12 @@ __xfs_bunmapi(
                                  */
                                 ASSERT(bno >= del.br_blockcount);
                                 bno -= del.br_blockcount;
-                                if (got.br_startoff > bno) {
-                                        if (--lastx >= 0) {
-                                                ep = xfs_iext_get_ext(ifp,
-                                                                      lastx);
-                                                xfs_bmbt_get_all(ep, &got);
-                                        }
-                                }
+                                if (got.br_startoff > bno && --lastx >= 0)
+                                        xfs_iext_get_extent(ifp, lastx, &got);
                                 continue;
                         } else if (del.br_state == XFS_EXT_UNWRITTEN) {
+                                struct xfs_bmbt_irec    prev;
+
                                 /*
                                  * This one is already unwritten.
                                  * It must have a written left neighbor.
@@ -5640,8 +5541,7 @@ __xfs_bunmapi(
                                  * try again.
                                  */
                                 ASSERT(lastx > 0);
-                                xfs_bmbt_get_all(xfs_iext_get_ext(ifp,
-                                                lastx - 1), &prev);
+                                xfs_iext_get_extent(ifp, lastx - 1, &prev);
                                 ASSERT(prev.br_state == XFS_EXT_NORM);
                                 ASSERT(!isnullstartblock(prev.br_startblock));
                                 ASSERT(del.br_startblock ==
@@ -5739,13 +5639,9 @@ nodelete:
                  */
                 if (bno != (xfs_fileoff_t)-1 && bno >= start) {
                         if (lastx >= 0) {
-                                ep = xfs_iext_get_ext(ifp, lastx);
-                                if (xfs_bmbt_get_startoff(ep) > bno) {
-                                        if (--lastx >= 0)
-                                                ep = xfs_iext_get_ext(ifp,
-                                                                      lastx);
-                                }
-                                xfs_bmbt_get_all(ep, &got);
+                                xfs_iext_get_extent(ifp, lastx, &got);
+                                if (got.br_startoff > bno && --lastx >= 0)
+                                        xfs_iext_get_extent(ifp, lastx, &got);
                         }
                         extno++;
                 }
diff --git a/fs/xfs/libxfs/xfs_bmap.h b/fs/xfs/libxfs/xfs_bmap.h
index 7cae6ec27fa6..ffed1f9208ce 100644
--- a/fs/xfs/libxfs/xfs_bmap.h
+++ b/fs/xfs/libxfs/xfs_bmap.h
@@ -237,14 +237,9 @@ int	xfs_bmap_shift_extents(struct xfs_trans *tp, struct xfs_inode *ip,
                 struct xfs_defer_ops *dfops, enum shift_direction direction,
                 int num_exts);
 int     xfs_bmap_split_extent(struct xfs_inode *ip, xfs_fileoff_t split_offset);
-struct xfs_bmbt_rec_host *
-        xfs_bmap_search_extents(struct xfs_inode *ip, xfs_fileoff_t bno,
-                int fork, int *eofp, xfs_extnum_t *lastxp,
-                struct xfs_bmbt_irec *gotp, struct xfs_bmbt_irec *prevp);
 int     xfs_bmapi_reserve_delalloc(struct xfs_inode *ip, int whichfork,
                 xfs_fileoff_t aoff, xfs_filblks_t len,
-                struct xfs_bmbt_irec *got, struct xfs_bmbt_irec *prev,
-                xfs_extnum_t *lastx, int eof);
+                struct xfs_bmbt_irec *got, xfs_extnum_t *lastx, int eof);
 
 enum xfs_bmap_intent_type {
         XFS_BMAP_MAP = 1,
diff --git a/fs/xfs/libxfs/xfs_inode_fork.c b/fs/xfs/libxfs/xfs_inode_fork.c
index 5fbe24c31679..222e103356c6 100644
--- a/fs/xfs/libxfs/xfs_inode_fork.c
+++ b/fs/xfs/libxfs/xfs_inode_fork.c
@@ -2003,3 +2003,49 @@ xfs_ifork_init_cow(
         ip->i_cformat = XFS_DINODE_FMT_EXTENTS;
         ip->i_cnextents = 0;
 }
+
+/*
+ * Lookup the extent covering bno.
+ *
+ * If there is an extent covering bno return the extent index, and store the
+ * expanded extent structure in *gotp, and the extent index in *idx.
+ * If there is no extent covering bno, but there is an extent after it (e.g.
+ * it lies in a hole) return that extent in *gotp and its index in *idx
+ * instead.
+ * If bno is beyond the last extent return false, and return the index after
+ * the last valid index in *idxp.
+ */
+bool
+xfs_iext_lookup_extent(
+        struct xfs_inode        *ip,
+        struct xfs_ifork        *ifp,
+        xfs_fileoff_t           bno,
+        xfs_extnum_t            *idxp,
+        struct xfs_bmbt_irec    *gotp)
+{
+        struct xfs_bmbt_rec_host *ep;
+
+        XFS_STATS_INC(ip->i_mount, xs_look_exlist);
+
+        ep = xfs_iext_bno_to_ext(ifp, bno, idxp);
+        if (!ep)
+                return false;
+        xfs_bmbt_get_all(ep, gotp);
+        return true;
+}
+
+/*
+ * Return true if there is an extent at index idx, and return the expanded
+ * extent structure at idx in that case.  Else return false.
+ */
+bool
+xfs_iext_get_extent(
+        struct xfs_ifork        *ifp,
+        xfs_extnum_t            idx,
+        struct xfs_bmbt_irec    *gotp)
+{
+        if (idx < 0 || idx >= xfs_iext_count(ifp))
+                return false;
+        xfs_bmbt_get_all(xfs_iext_get_ext(ifp, idx), gotp);
+        return true;
+}
diff --git a/fs/xfs/libxfs/xfs_inode_fork.h b/fs/xfs/libxfs/xfs_inode_fork.h
index 8bf112e29aa1..7fb8365326d1 100644
--- a/fs/xfs/libxfs/xfs_inode_fork.h
+++ b/fs/xfs/libxfs/xfs_inode_fork.h
@@ -182,6 +182,12 @@ void		xfs_iext_irec_compact_pages(struct xfs_ifork *);
 void            xfs_iext_irec_compact_full(struct xfs_ifork *);
 void            xfs_iext_irec_update_extoffs(struct xfs_ifork *, int, int);
 
+bool            xfs_iext_lookup_extent(struct xfs_inode *ip,
+                        struct xfs_ifork *ifp, xfs_fileoff_t bno,
+                        xfs_extnum_t *idxp, struct xfs_bmbt_irec *gotp);
+bool            xfs_iext_get_extent(struct xfs_ifork *ifp, xfs_extnum_t idx,
+                        struct xfs_bmbt_irec *gotp);
+
 extern struct kmem_zone *xfs_ifork_zone;
 
 extern void xfs_ifork_init_cow(struct xfs_inode *ip);
diff --git a/fs/xfs/libxfs/xfs_types.h b/fs/xfs/libxfs/xfs_types.h
index cf044c0f4d41..717909f2f7b7 100644
--- a/fs/xfs/libxfs/xfs_types.h
+++ b/fs/xfs/libxfs/xfs_types.h
@@ -57,7 +57,6 @@ typedef __int64_t	xfs_sfiloff_t;	/* signed block number in a file */
 
 #define NULLAGBLOCK     ((xfs_agblock_t)-1)
 #define NULLAGNUMBER    ((xfs_agnumber_t)-1)
-#define NULLEXTNUM      ((xfs_extnum_t)-1)
 
 #define NULLCOMMITLSN   ((xfs_lsn_t)-1)
 
diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index dd6cacf59b5a..ab266d66124d 100644
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -777,7 +777,7 @@ xfs_map_cow(
 {
         struct xfs_inode        *ip = XFS_I(inode);
         struct xfs_bmbt_irec    imap;
-        bool                    is_cow = false, need_alloc = false;
+        bool                    is_cow = false;
         int                     error;
 
         /*
@@ -795,7 +795,7 @@ xfs_map_cow(
          * Else we need to check if there is a COW mapping at this offset.
          */
         xfs_ilock(ip, XFS_ILOCK_SHARED);
-        is_cow = xfs_reflink_find_cow_mapping(ip, offset, &imap, &need_alloc);
+        is_cow = xfs_reflink_find_cow_mapping(ip, offset, &imap);
         xfs_iunlock(ip, XFS_ILOCK_SHARED);
 
         if (!is_cow)
@@ -805,7 +805,7 @@ xfs_map_cow(
          * And if the COW mapping has a delayed extent here we need to
          * allocate real space for it now.
          */
-        if (need_alloc) {
+        if (isnullstartblock(imap.br_startblock)) {
                 error = xfs_iomap_write_allocate(ip, XFS_COW_FORK, offset,
                                 &imap);
                 if (error)
@@ -1311,7 +1311,6 @@ __xfs_get_blocks(
         ssize_t                 size;
         int                     new = 0;
         bool                    is_cow = false;
-        bool                    need_alloc = false;
 
         BUG_ON(create && !direct);
 
@@ -1337,9 +1336,11 @@ __xfs_get_blocks(
         end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + size);
         offset_fsb = XFS_B_TO_FSBT(mp, offset);
 
-        if (create && direct && xfs_is_reflink_inode(ip))
-                is_cow = xfs_reflink_find_cow_mapping(ip, offset, &imap,
-                                        &need_alloc);
+        if (create && direct && xfs_is_reflink_inode(ip)) {
+                is_cow = xfs_reflink_find_cow_mapping(ip, offset, &imap);
+                ASSERT(!is_cow || !isnullstartblock(imap.br_startblock));
+        }
+
         if (!is_cow) {
                 error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb,
                                         &imap, &nimaps, XFS_BMAPI_ENTIRE);
@@ -1356,7 +1357,6 @@ __xfs_get_blocks(
                         xfs_reflink_trim_irec_to_next_cow(ip, offset_fsb,
                                         &imap);
         }
-        ASSERT(!need_alloc);
         if (error)
                 goto out_unlock;
 
diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
index 436e109bb01e..2272190b70ae 100644
--- a/fs/xfs/xfs_iomap.c
+++ b/fs/xfs/xfs_iomap.c
@@ -395,11 +395,12 @@ xfs_iomap_prealloc_size(
         struct xfs_inode        *ip,
         loff_t                  offset,
         loff_t                  count,
-        xfs_extnum_t            idx,
-        struct xfs_bmbt_irec    *prev)
+        xfs_extnum_t            idx)
 {
         struct xfs_mount        *mp = ip->i_mount;
+        struct xfs_ifork        *ifp = XFS_IFORK_PTR(ip, XFS_DATA_FORK);
         xfs_fileoff_t           offset_fsb = XFS_B_TO_FSBT(mp, offset);
+        struct xfs_bmbt_irec    prev;
         int                     shift = 0;
         int64_t                 freesp;
         xfs_fsblock_t           qblocks;
@@ -419,8 +420,8 @@ xfs_iomap_prealloc_size(
          */
         if ((mp->m_flags & XFS_MOUNT_DFLT_IOSIZE) ||
             XFS_ISIZE(ip) < XFS_FSB_TO_B(mp, mp->m_dalign) ||
-            idx == 0 ||
-            prev->br_startoff + prev->br_blockcount < offset_fsb)
+            !xfs_iext_get_extent(ifp, idx - 1, &prev) ||
+            prev.br_startoff + prev.br_blockcount < offset_fsb)
                 return mp->m_writeio_blocks;
 
         /*
@@ -439,8 +440,8 @@ xfs_iomap_prealloc_size(
          * always extends to MAXEXTLEN rather than falling short due to things
          * like stripe unit/width alignment of real extents.
          */
-        if (prev->br_blockcount <= (MAXEXTLEN >> 1))
-                alloc_blocks = prev->br_blockcount << 1;
+        if (prev.br_blockcount <= (MAXEXTLEN >> 1))
+                alloc_blocks = prev.br_blockcount << 1;
         else
                 alloc_blocks = XFS_B_TO_FSB(mp, offset);
         if (!alloc_blocks)
@@ -538,7 +539,6 @@ xfs_file_iomap_begin_delay(
         xfs_fileoff_t           end_fsb, orig_end_fsb;
         int                     error = 0, eof = 0;
         struct xfs_bmbt_irec    got;
-        struct xfs_bmbt_irec    prev;
         xfs_extnum_t            idx;
 
         ASSERT(!XFS_IS_REALTIME_INODE(ip));
@@ -563,8 +563,7 @@ xfs_file_iomap_begin_delay(
                         goto out_unlock;
         }
 
-        xfs_bmap_search_extents(ip, offset_fsb, XFS_DATA_FORK, &eof, &idx,
-                        &got, &prev);
+        eof = !xfs_iext_lookup_extent(ip, ifp, offset_fsb, &idx, &got);
         if (!eof && got.br_startoff <= offset_fsb) {
                 if (xfs_is_reflink_inode(ip)) {
                         bool            shared;
@@ -601,8 +600,7 @@ xfs_file_iomap_begin_delay(
         if (eof) {
                 xfs_fsblock_t   prealloc_blocks;
 
-                prealloc_blocks =
-                        xfs_iomap_prealloc_size(ip, offset, count, idx, &prev);
+                prealloc_blocks = xfs_iomap_prealloc_size(ip, offset, count, idx);
                 if (prealloc_blocks) {
                         xfs_extlen_t    align;
                         xfs_off_t       end_offset;
@@ -622,8 +620,7 @@ xfs_file_iomap_begin_delay(
 
 retry:
         error = xfs_bmapi_reserve_delalloc(ip, XFS_DATA_FORK, offset_fsb,
-                        end_fsb - offset_fsb, &got,
-                        &prev, &idx, eof);
+                        end_fsb - offset_fsb, &got, &idx, eof);
         switch (error) {
         case 0:
                 break;
diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
index 0edf835af32d..56372bee08c5 100644
--- a/fs/xfs/xfs_reflink.c
+++ b/fs/xfs/xfs_reflink.c
@@ -243,10 +243,11 @@ xfs_reflink_reserve_cow(
         struct xfs_bmbt_irec    *imap,
         bool                    *shared)
 {
-        struct xfs_bmbt_irec    got, prev;
+        struct xfs_ifork        *ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK);
+        struct xfs_bmbt_irec    got;
         xfs_fileoff_t           end_fsb, orig_end_fsb;
-        int                     eof = 0, error = 0;
-        bool                    trimmed;
+        int                     error = 0;
+        bool                    eof = false, trimmed;
         xfs_extnum_t            idx;
         xfs_extlen_t            align;
 
@@ -258,8 +259,9 @@ xfs_reflink_reserve_cow(
          * extent list is generally faster than going out to the shared extent
          * tree.
          */
-        xfs_bmap_search_extents(ip, imap->br_startoff, XFS_COW_FORK, &eof, &idx,
-                        &got, &prev);
+
+        if (!xfs_iext_lookup_extent(ip, ifp, imap->br_startoff, &idx, &got))
+                eof = true;
         if (!eof && got.br_startoff <= imap->br_startoff) {
                 trace_xfs_reflink_cow_found(ip, imap);
                 xfs_trim_extent(imap, got.br_startoff, got.br_blockcount);
@@ -293,7 +295,7 @@ xfs_reflink_reserve_cow(
 
 retry:
         error = xfs_bmapi_reserve_delalloc(ip, XFS_COW_FORK, imap->br_startoff,
-                        end_fsb - imap->br_startoff, &got, &prev, &idx, eof);
+                        end_fsb - imap->br_startoff, &got, &idx, eof);
         switch (error) {
         case 0:
                 break;
@@ -418,87 +420,65 @@ xfs_reflink_allocate_cow_range(
 }
 
 /*
- * Find the CoW reservation (and whether or not it needs block allocation)
- * for a given byte offset of a file.
+ * Find the CoW reservation for a given byte offset of a file.
  */
 bool
 xfs_reflink_find_cow_mapping(
         struct xfs_inode                *ip,
         xfs_off_t                       offset,
-        struct xfs_bmbt_irec            *imap,
-        bool                            *need_alloc)
+        struct xfs_bmbt_irec            *imap)
 {
-        struct xfs_bmbt_irec            irec;
-        struct xfs_ifork                *ifp;
-        struct xfs_bmbt_rec_host        *gotp;
-        xfs_fileoff_t                   bno;
+        struct xfs_ifork                *ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK);
+        xfs_fileoff_t                   offset_fsb;
+        struct xfs_bmbt_irec            got;
         xfs_extnum_t                    idx;
 
         ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL | XFS_ILOCK_SHARED));
         ASSERT(xfs_is_reflink_inode(ip));
 
-        /* Find the extent in the CoW fork. */
-        ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK);
-        bno = XFS_B_TO_FSBT(ip->i_mount, offset);
-        gotp = xfs_iext_bno_to_ext(ifp, bno, &idx);
-        if (!gotp)
+        offset_fsb = XFS_B_TO_FSBT(ip->i_mount, offset);
+        if (!xfs_iext_lookup_extent(ip, ifp, offset_fsb, &idx, &got))
                 return false;
-
-        xfs_bmbt_get_all(gotp, &irec);
-        if (bno >= irec.br_startoff + irec.br_blockcount ||
-            bno < irec.br_startoff)
+        if (got.br_startoff > offset_fsb)
                 return false;
 
         trace_xfs_reflink_find_cow_mapping(ip, offset, 1, XFS_IO_OVERWRITE,
-                        &irec);
-
-        /* If it's still delalloc, we must allocate later. */
-        *imap = irec;
-        *need_alloc = !!(isnullstartblock(irec.br_startblock));
-
+                        &got);
+        *imap = got;
         return true;
 }
 
 /*
  * Trim an extent to end at the next CoW reservation past offset_fsb.
  */
-int
+void
 xfs_reflink_trim_irec_to_next_cow(
         struct xfs_inode                *ip,
         xfs_fileoff_t                   offset_fsb,
         struct xfs_bmbt_irec            *imap)
 {
-        struct xfs_bmbt_irec            irec;
-        struct xfs_ifork                *ifp;
-        struct xfs_bmbt_rec_host        *gotp;
+        struct xfs_ifork                *ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK);
+        struct xfs_bmbt_irec            got;
         xfs_extnum_t                    idx;
 
         if (!xfs_is_reflink_inode(ip))
-                return 0;
+                return;
 
         /* Find the extent in the CoW fork. */
-        ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK);
-        gotp = xfs_iext_bno_to_ext(ifp, offset_fsb, &idx);
-        if (!gotp)
-                return 0;
-        xfs_bmbt_get_all(gotp, &irec);
+        if (!xfs_iext_lookup_extent(ip, ifp, offset_fsb, &idx, &got))
+                return;
 
         /* This is the extent before; try sliding up one. */
-        if (irec.br_startoff < offset_fsb) {
-                idx++;
-                if (idx >= xfs_iext_count(ifp))
-                        return 0;
-                gotp = xfs_iext_get_ext(ifp, idx);
-                xfs_bmbt_get_all(gotp, &irec);
+        if (got.br_startoff < offset_fsb) {
+                if (!xfs_iext_get_extent(ifp, idx + 1, &got))
+                        return;
         }
 
-        if (irec.br_startoff >= imap->br_startoff + imap->br_blockcount)
-                return 0;
+        if (got.br_startoff >= imap->br_startoff + imap->br_blockcount)
+                return;
 
-        imap->br_blockcount = irec.br_startoff - imap->br_startoff;
+        imap->br_blockcount = got.br_startoff - imap->br_startoff;
         trace_xfs_reflink_trim_irec(ip, imap);
-
-        return 0;
 }
 
 /*
@@ -512,18 +492,15 @@ xfs_reflink_cancel_cow_blocks(
         xfs_fileoff_t                   end_fsb)
 {
         struct xfs_ifork                *ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK);
-        struct xfs_bmbt_irec            got, prev, del;
+        struct xfs_bmbt_irec            got, del;
         xfs_extnum_t                    idx;
         xfs_fsblock_t                   firstfsb;
         struct xfs_defer_ops            dfops;
-        int                             error = 0, eof = 0;
+        int                             error = 0;
 
         if (!xfs_is_reflink_inode(ip))
                 return 0;
-
-        xfs_bmap_search_extents(ip, offset_fsb, XFS_COW_FORK, &eof, &idx,
-                        &got, &prev);
-        if (eof)
+        if (!xfs_iext_lookup_extent(ip, ifp, offset_fsb, &idx, &got))
                 return 0;
 
         while (got.br_startoff < end_fsb) {
@@ -566,9 +543,8 @@ xfs_reflink_cancel_cow_blocks(
                         xfs_bmap_del_extent_cow(ip, &idx, &got, &del);
                 }
 
-                if (++idx >= xfs_iext_count(ifp))
+                if (!xfs_iext_get_extent(ifp, ++idx, &got))
                         break;
-                xfs_bmbt_get_all(xfs_iext_get_ext(ifp, idx), &got);
         }
 
         /* clear tag if cow fork is emptied */
@@ -638,13 +614,13 @@ xfs_reflink_end_cow(
         xfs_off_t                       count)
 {
         struct xfs_ifork                *ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK);
-        struct xfs_bmbt_irec            got, prev, del;
+        struct xfs_bmbt_irec            got, del;
         struct xfs_trans                *tp;
         xfs_fileoff_t                   offset_fsb;
         xfs_fileoff_t                   end_fsb;
         xfs_fsblock_t                   firstfsb;
         struct xfs_defer_ops            dfops;
-        int                             error, eof = 0;
+        int                             error;
         unsigned int                    resblks;
         xfs_filblks_t                   rlen;
         xfs_extnum_t                    idx;
@@ -668,13 +644,11 @@ xfs_reflink_end_cow(
         xfs_ilock(ip, XFS_ILOCK_EXCL);
         xfs_trans_ijoin(tp, ip, 0);
 
-        xfs_bmap_search_extents(ip, end_fsb - 1, XFS_COW_FORK, &eof, &idx,
-                        &got, &prev);
-
         /* If there is a hole at end_fsb - 1 go to the previous extent */
-        if (eof || got.br_startoff > end_fsb) {
+        if (!xfs_iext_lookup_extent(ip, ifp, end_fsb - 1, &idx, &got) ||
+            got.br_startoff > end_fsb) {
                 ASSERT(idx > 0);
-                xfs_bmbt_get_all(xfs_iext_get_ext(ifp, --idx), &got);
+                xfs_iext_get_extent(ifp, --idx, &got);
         }
 
         /* Walk backwards until we're out of the I/O range... */
@@ -722,11 +696,9 @@ xfs_reflink_end_cow(
                 error = xfs_defer_finish(&tp, &dfops, ip);
                 if (error)
                         goto out_defer;
-
 next_extent:
-                if (idx < 0)
+                if (!xfs_iext_get_extent(ifp, idx, &got))
                         break;
-                xfs_bmbt_get_all(xfs_iext_get_ext(ifp, idx), &got);
         }
 
         error = xfs_trans_commit(tp);
diff --git a/fs/xfs/xfs_reflink.h b/fs/xfs/xfs_reflink.h
index 97ea9b487884..aa6a4d64bd35 100644
--- a/fs/xfs/xfs_reflink.h
+++ b/fs/xfs/xfs_reflink.h
@@ -31,8 +31,8 @@ extern int xfs_reflink_reserve_cow(struct xfs_inode *ip,
 extern int xfs_reflink_allocate_cow_range(struct xfs_inode *ip,
                 xfs_off_t offset, xfs_off_t count);
 extern bool xfs_reflink_find_cow_mapping(struct xfs_inode *ip, xfs_off_t offset,
-                struct xfs_bmbt_irec *imap, bool *need_alloc);
-extern int xfs_reflink_trim_irec_to_next_cow(struct xfs_inode *ip,
+                struct xfs_bmbt_irec *imap);
+extern void xfs_reflink_trim_irec_to_next_cow(struct xfs_inode *ip,
                 xfs_fileoff_t offset_fsb, struct xfs_bmbt_irec *imap);
 
 extern int xfs_reflink_cancel_cow_blocks(struct xfs_inode *ip,