6 files changed, 461 insertions, 83 deletions

diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index 60cfa90163b8..e8696f5a8041 100644
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -5526,52 +5526,92 @@ xfs_bmse_shift_one(
         int                             *current_ext,
         struct xfs_bmbt_rec_host        *gotp,
         struct xfs_btree_cur            *cur,
-        int                             *logflags)
+        int                             *logflags,
+        enum shift_direction            direction)
 {
         struct xfs_ifork                *ifp;
         struct xfs_mount                *mp;
         xfs_fileoff_t                   startoff;
-        struct xfs_bmbt_rec_host        *leftp;
+        struct xfs_bmbt_rec_host        *adj_irecp;
         struct xfs_bmbt_irec            got;
-        struct xfs_bmbt_irec            left;
+        struct xfs_bmbt_irec            adj_irec;
         int                             error;
         int                             i;
+        int                             total_extents;
 
         mp = ip->i_mount;
         ifp = XFS_IFORK_PTR(ip, whichfork);
+        total_extents = ifp->if_bytes / sizeof(xfs_bmbt_rec_t);
 
         xfs_bmbt_get_all(gotp, &got);
-        startoff = got.br_startoff - offset_shift_fsb;
 
         /* delalloc extents should be prevented by caller */
         XFS_WANT_CORRUPTED_RETURN(mp, !isnullstartblock(got.br_startblock));
 
-        /*
-         * Check for merge if we've got an extent to the left, otherwise make
-         * sure there's enough room at the start of the file for the shift.
-         */
-        if (*current_ext) {
-                /* grab the left extent and check for a large enough hole */
-                leftp = xfs_iext_get_ext(ifp, *current_ext - 1);
-                xfs_bmbt_get_all(leftp, &left);
+        if (direction == SHIFT_LEFT) {
+                startoff = got.br_startoff - offset_shift_fsb;
+
+                /*
+                 * Check for merge if we've got an extent to the left,
+                 * otherwise make sure there's enough room at the start
+                 * of the file for the shift.
+                 */
+                if (!*current_ext) {
+                        if (got.br_startoff < offset_shift_fsb)
+                                return -EINVAL;
+                        goto update_current_ext;
+                }
+                /*
+                 * grab the left extent and check for a large
+                 * enough hole.
+                 */
+                adj_irecp = xfs_iext_get_ext(ifp, *current_ext - 1);
+                xfs_bmbt_get_all(adj_irecp, &adj_irec);
 
-                if (startoff < left.br_startoff + left.br_blockcount)
+                if (startoff <
+                    adj_irec.br_startoff + adj_irec.br_blockcount)
                         return -EINVAL;
 
                 /* check whether to merge the extent or shift it down */
-                if (xfs_bmse_can_merge(&left, &got, offset_shift_fsb)) {
+                if (xfs_bmse_can_merge(&adj_irec, &got,
+                                       offset_shift_fsb)) {
                         return xfs_bmse_merge(ip, whichfork, offset_shift_fsb,
-                                              *current_ext, gotp, leftp, cur,
-                                              logflags);
+                                              *current_ext, gotp, adj_irecp,
+                                              cur, logflags);
                 }
-        } else if (got.br_startoff < offset_shift_fsb)
-                return -EINVAL;
-
+        } else {
+                startoff = got.br_startoff + offset_shift_fsb;
+                /* nothing to move if this is the last extent */
+                if (*current_ext >= (total_extents - 1))
+                        goto update_current_ext;
+                /*
+                 * If this is not the last extent in the file, make sure there
+                 * is enough room between current extent and next extent for
+                 * accommodating the shift.
+                 */
+                adj_irecp = xfs_iext_get_ext(ifp, *current_ext + 1);
+                xfs_bmbt_get_all(adj_irecp, &adj_irec);
+                if (startoff + got.br_blockcount > adj_irec.br_startoff)
+                        return -EINVAL;
+                /*
+                 * Unlike a left shift (which involves a hole punch),
+                 * a right shift does not modify extent neighbors
+                 * in any way. We should never find mergeable extents
+                 * in this scenario. Check anyways and warn if we
+                 * encounter two extents that could be one.
+                 */
+                if (xfs_bmse_can_merge(&got, &adj_irec, offset_shift_fsb))
+                        WARN_ON_ONCE(1);
+        }
         /*
          * Increment the extent index for the next iteration, update the start
          * offset of the in-core extent and update the btree if applicable.
          */
-        (*current_ext)++;
+update_current_ext:
+        if (direction == SHIFT_LEFT)
+                (*current_ext)++;
+        else
+                (*current_ext)--;
         xfs_bmbt_set_startoff(gotp, startoff);
         *logflags |= XFS_ILOG_CORE;
         if (!cur) {
@@ -5587,14 +5627,14 @@ xfs_bmse_shift_one(
 
         got.br_startoff = startoff;
         return xfs_bmbt_update(cur, got.br_startoff, got.br_startblock,
-                                got.br_blockcount, got.br_state);
+                               got.br_blockcount, got.br_state);
 }
 
 /*
- * Shift extent records to the left to cover a hole.
+ * Shift extent records to the left/right to cover/create a hole.
  *
  * The maximum number of extents to be shifted in a single operation is
- * @num_exts. @start_fsb specifies the file offset to start the shift and the
+ * @num_exts. @stop_fsb specifies the file offset at which to stop shift and the
  * file offset where we've left off is returned in @next_fsb. @offset_shift_fsb
  * is the length by which each extent is shifted. If there is no hole to shift
  * the extents into, this will be considered invalid operation and we abort
@@ -5604,12 +5644,13 @@ int
 xfs_bmap_shift_extents(
         struct xfs_trans        *tp,
         struct xfs_inode        *ip,
-        xfs_fileoff_t           start_fsb,
+        xfs_fileoff_t           *next_fsb,
         xfs_fileoff_t           offset_shift_fsb,
         int                     *done,
-        xfs_fileoff_t           *next_fsb,
+        xfs_fileoff_t           stop_fsb,
         xfs_fsblock_t           *firstblock,
         struct xfs_bmap_free    *flist,
+        enum shift_direction    direction,
         int                     num_exts)
 {
         struct xfs_btree_cur            *cur = NULL;
@@ -5619,10 +5660,11 @@ xfs_bmap_shift_extents(
         struct xfs_ifork                *ifp;
         xfs_extnum_t                    nexts = 0;
         xfs_extnum_t                    current_ext;
+        xfs_extnum_t                    total_extents;
+        xfs_extnum_t                    stop_extent;
         int                             error = 0;
         int                             whichfork = XFS_DATA_FORK;
         int                             logflags = 0;
-        int                             total_extents;
 
         if (unlikely(XFS_TEST_ERROR(
             (XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_EXTENTS &&
@@ -5638,6 +5680,8 @@ xfs_bmap_shift_extents(
 
         ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL));
         ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
+        ASSERT(direction == SHIFT_LEFT || direction == SHIFT_RIGHT);
+        ASSERT(*next_fsb != NULLFSBLOCK || direction == SHIFT_RIGHT);
 
         ifp = XFS_IFORK_PTR(ip, whichfork);
         if (!(ifp->if_flags & XFS_IFEXTENTS)) {
@@ -5655,43 +5699,83 @@ xfs_bmap_shift_extents(
         }
 
         /*
+         * There may be delalloc extents in the data fork before the range we
+         * are collapsing out, so we cannot use the count of real extents here.
+         * Instead we have to calculate it from the incore fork.
+         */
+        total_extents = ifp->if_bytes / sizeof(xfs_bmbt_rec_t);
+        if (total_extents == 0) {
+                *done = 1;
+                goto del_cursor;
+        }
+
+        /*
+         * In case of first right shift, we need to initialize next_fsb
+         */
+        if (*next_fsb == NULLFSBLOCK) {
+                gotp = xfs_iext_get_ext(ifp, total_extents - 1);
+                xfs_bmbt_get_all(gotp, &got);
+                *next_fsb = got.br_startoff;
+                if (stop_fsb > *next_fsb) {
+                        *done = 1;
+                        goto del_cursor;
+                }
+        }
+
+        /* Lookup the extent index at which we have to stop */
+        if (direction == SHIFT_RIGHT) {
+                gotp = xfs_iext_bno_to_ext(ifp, stop_fsb, &stop_extent);
+                /* Make stop_extent exclusive of shift range */
+                stop_extent--;
+        } else
+                stop_extent = total_extents;
+
+        /*
          * Look up the extent index for the fsb where we start shifting. We can
          * henceforth iterate with current_ext as extent list changes are locked
          * out via ilock.
          *
          * gotp can be null in 2 cases: 1) if there are no extents or 2)
-         * start_fsb lies in a hole beyond which there are no extents. Either
+         * *next_fsb lies in a hole beyond which there are no extents. Either
          * way, we are done.
          */
-        gotp = xfs_iext_bno_to_ext(ifp, start_fsb, &current_ext);
+        gotp = xfs_iext_bno_to_ext(ifp, *next_fsb, &current_ext);
         if (!gotp) {
                 *done = 1;
                 goto del_cursor;
         }
 
-        /*
-         * There may be delalloc extents in the data fork before the range we
-         * are collapsing out, so we cannot use the count of real extents here.
-         * Instead we have to calculate it from the incore fork.
-         */
-        total_extents = ifp->if_bytes / sizeof(xfs_bmbt_rec_t);
-        while (nexts++ < num_exts && current_ext < total_extents) {
+        /* some sanity checking before we finally start shifting extents */
+        if ((direction == SHIFT_LEFT && current_ext >= stop_extent) ||
+             (direction == SHIFT_RIGHT && current_ext <= stop_extent)) {
+                error = -EIO;
+                goto del_cursor;
+        }
+
+        while (nexts++ < num_exts) {
                 error = xfs_bmse_shift_one(ip, whichfork, offset_shift_fsb,
-                                        &current_ext, gotp, cur, &logflags);
+                                           &current_ext, gotp, cur, &logflags,
+                                           direction);
                 if (error)
                         goto del_cursor;
+                /*
+                 * If there was an extent merge during the shift, the extent
+                 * count can change. Update the total and grade the next record.
+                 */
+                if (direction == SHIFT_LEFT) {
+                        total_extents = ifp->if_bytes / sizeof(xfs_bmbt_rec_t);
+                        stop_extent = total_extents;
+                }
 
-                /* update total extent count and grab the next record */
-                total_extents = ifp->if_bytes / sizeof(xfs_bmbt_rec_t);
-                if (current_ext >= total_extents)
+                if (current_ext == stop_extent) {
+                        *done = 1;
+                        *next_fsb = NULLFSBLOCK;
                         break;
+                }
                 gotp = xfs_iext_get_ext(ifp, current_ext);
         }
 
-        /* Check if we are done */
-        if (current_ext == total_extents) {
-                *done = 1;
-        } else if (next_fsb) {
+        if (!*done) {
                 xfs_bmbt_get_all(gotp, &got);
                 *next_fsb = got.br_startoff;
         }
@@ -5706,3 +5790,189 @@ del_cursor:
 
         return error;
 }
+
+/*
+ * Splits an extent into two extents at split_fsb block such that it is
+ * the first block of the current_ext. @current_ext is a target extent
+ * to be split. @split_fsb is a block where the extents is split.
+ * If split_fsb lies in a hole or the first block of extents, just return 0.
+ */
+STATIC int
+xfs_bmap_split_extent_at(
+        struct xfs_trans        *tp,
+        struct xfs_inode        *ip,
+        xfs_fileoff_t           split_fsb,
+        xfs_fsblock_t           *firstfsb,
+        struct xfs_bmap_free    *free_list)
+{
+        int                             whichfork = XFS_DATA_FORK;
+        struct xfs_btree_cur            *cur = NULL;
+        struct xfs_bmbt_rec_host        *gotp;
+        struct xfs_bmbt_irec            got;
+        struct xfs_bmbt_irec            new; /* split extent */
+        struct xfs_mount                *mp = ip->i_mount;
+        struct xfs_ifork                *ifp;
+        xfs_fsblock_t                   gotblkcnt; /* new block count for got */
+        xfs_extnum_t                    current_ext;
+        int                             error = 0;
+        int                             logflags = 0;
+        int                             i = 0;
+
+        if (unlikely(XFS_TEST_ERROR(
+            (XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_EXTENTS &&
+             XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_BTREE),
+             mp, XFS_ERRTAG_BMAPIFORMAT, XFS_RANDOM_BMAPIFORMAT))) {
+                XFS_ERROR_REPORT("xfs_bmap_split_extent_at",
+                                 XFS_ERRLEVEL_LOW, mp);
+                return -EFSCORRUPTED;
+        }
+
+        if (XFS_FORCED_SHUTDOWN(mp))
+                return -EIO;
+
+        ifp = XFS_IFORK_PTR(ip, whichfork);
+        if (!(ifp->if_flags & XFS_IFEXTENTS)) {
+                /* Read in all the extents */
+                error = xfs_iread_extents(tp, ip, whichfork);
+                if (error)
+                        return error;
+        }
+
+        /*
+         * gotp can be null in 2 cases: 1) if there are no extents
+         * or 2) split_fsb lies in a hole beyond which there are
+         * no extents. Either way, we are done.
+         */
+        gotp = xfs_iext_bno_to_ext(ifp, split_fsb, &current_ext);
+        if (!gotp)
+                return 0;
+
+        xfs_bmbt_get_all(gotp, &got);
+
+        /*
+         * Check split_fsb lies in a hole or the start boundary offset
+         * of the extent.
+         */
+        if (got.br_startoff >= split_fsb)
+                return 0;
+
+        gotblkcnt = split_fsb - got.br_startoff;
+        new.br_startoff = split_fsb;
+        new.br_startblock = got.br_startblock + gotblkcnt;
+        new.br_blockcount = got.br_blockcount - gotblkcnt;
+        new.br_state = got.br_state;
+
+        if (ifp->if_flags & XFS_IFBROOT) {
+                cur = xfs_bmbt_init_cursor(mp, tp, ip, whichfork);
+                cur->bc_private.b.firstblock = *firstfsb;
+                cur->bc_private.b.flist = free_list;
+                cur->bc_private.b.flags = 0;
+                error = xfs_bmbt_lookup_eq(cur, got.br_startoff,
+                                got.br_startblock,
+                                got.br_blockcount,
+                                &i);
+                if (error)
+                        goto del_cursor;
+                XFS_WANT_CORRUPTED_GOTO(mp, i == 1, del_cursor);
+        }
+
+        xfs_bmbt_set_blockcount(gotp, gotblkcnt);
+        got.br_blockcount = gotblkcnt;
+
+        logflags = XFS_ILOG_CORE;
+        if (cur) {
+                error = xfs_bmbt_update(cur, got.br_startoff,
+                                got.br_startblock,
+                                got.br_blockcount,
+                                got.br_state);
+                if (error)
+                        goto del_cursor;
+        } else
+                logflags |= XFS_ILOG_DEXT;
+
+        /* Add new extent */
+        current_ext++;
+        xfs_iext_insert(ip, current_ext, 1, &new, 0);
+        XFS_IFORK_NEXT_SET(ip, whichfork,
+                           XFS_IFORK_NEXTENTS(ip, whichfork) + 1);
+
+        if (cur) {
+                error = xfs_bmbt_lookup_eq(cur, new.br_startoff,
+                                new.br_startblock, new.br_blockcount,
+                                &i);
+                if (error)
+                        goto del_cursor;
+                XFS_WANT_CORRUPTED_GOTO(mp, i == 0, del_cursor);
+                cur->bc_rec.b.br_state = new.br_state;
+
+                error = xfs_btree_insert(cur, &i);
+                if (error)
+                        goto del_cursor;
+                XFS_WANT_CORRUPTED_GOTO(mp, i == 1, del_cursor);
+        }
+
+        /*
+         * Convert to a btree if necessary.
+         */
+        if (xfs_bmap_needs_btree(ip, whichfork)) {
+                int tmp_logflags; /* partial log flag return val */
+
+                ASSERT(cur == NULL);
+                error = xfs_bmap_extents_to_btree(tp, ip, firstfsb, free_list,
+                                &cur, 0, &tmp_logflags, whichfork);
+                logflags |= tmp_logflags;
+        }
+
+del_cursor:
+        if (cur) {
+                cur->bc_private.b.allocated = 0;
+                xfs_btree_del_cursor(cur,
+                                error ? XFS_BTREE_ERROR : XFS_BTREE_NOERROR);
+        }
+
+        if (logflags)
+                xfs_trans_log_inode(tp, ip, logflags);
+        return error;
+}
+
+int
+xfs_bmap_split_extent(
+        struct xfs_inode        *ip,
+        xfs_fileoff_t           split_fsb)
+{
+        struct xfs_mount        *mp = ip->i_mount;
+        struct xfs_trans        *tp;
+        struct xfs_bmap_free    free_list;
+        xfs_fsblock_t           firstfsb;
+        int                     committed;
+        int                     error;
+
+        tp = xfs_trans_alloc(mp, XFS_TRANS_DIOSTRAT);
+        error = xfs_trans_reserve(tp, &M_RES(mp)->tr_write,
+                        XFS_DIOSTRAT_SPACE_RES(mp, 0), 0);
+        if (error) {
+                xfs_trans_cancel(tp, 0);
+                return error;
+        }
+
+        xfs_ilock(ip, XFS_ILOCK_EXCL);
+        xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
+
+        xfs_bmap_init(&free_list, &firstfsb);
+
+        error = xfs_bmap_split_extent_at(tp, ip, split_fsb,
+                        &firstfsb, &free_list);
+        if (error)
+                goto out;
+
+        error = xfs_bmap_finish(&tp, &free_list, &committed);
+        if (error)
+                goto out;
+
+        return xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
+
+
+out:
+        xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT);
+        return error;
+}
diff --git a/fs/xfs/libxfs/xfs_bmap.h b/fs/xfs/libxfs/xfs_bmap.h
index b9d8a499d2c4..6aaa0c1c7200 100644
--- a/fs/xfs/libxfs/xfs_bmap.h
+++ b/fs/xfs/libxfs/xfs_bmap.h
@@ -166,6 +166,11 @@ static inline void xfs_bmap_init(xfs_bmap_free_t *flp, xfs_fsblock_t *fbp)
  */
 #define XFS_BMAP_MAX_SHIFT_EXTENTS      1
 
+enum shift_direction {
+        SHIFT_LEFT = 0,
+        SHIFT_RIGHT,
+};
+
 #ifdef DEBUG
 void    xfs_bmap_trace_exlist(struct xfs_inode *ip, xfs_extnum_t cnt,
                 int whichfork, unsigned long caller_ip);
@@ -211,8 +216,10 @@ int	xfs_check_nostate_extents(struct xfs_ifork *ifp, xfs_extnum_t idx,
                 xfs_extnum_t num);
 uint    xfs_default_attroffset(struct xfs_inode *ip);
 int     xfs_bmap_shift_extents(struct xfs_trans *tp, struct xfs_inode *ip,
-                xfs_fileoff_t start_fsb, xfs_fileoff_t offset_shift_fsb,
-                int *done, xfs_fileoff_t *next_fsb, xfs_fsblock_t *firstblock,
-                struct xfs_bmap_free *flist, int num_exts);
+                xfs_fileoff_t *next_fsb, xfs_fileoff_t offset_shift_fsb,
+                int *done, xfs_fileoff_t stop_fsb, xfs_fsblock_t *firstblock,
+                struct xfs_bmap_free *flist, enum shift_direction direction,
+                int num_exts);
+int     xfs_bmap_split_extent(struct xfs_inode *ip, xfs_fileoff_t split_offset);
 
 #endif  /* __XFS_BMAP_H__ */
diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c
index 22a5dcb70b32..fe1f11b96d0d 100644
--- a/fs/xfs/xfs_bmap_util.c
+++ b/fs/xfs/xfs_bmap_util.c
@@ -1376,22 +1376,19 @@ out:
 }
 
 /*
- * xfs_collapse_file_space()
- *      This routine frees disk space and shift extent for the given file.
- *      The first thing we do is to free data blocks in the specified range
- *      by calling xfs_free_file_space(). It would also sync dirty data
- *      and invalidate page cache over the region on which collapse range
- *      is working. And Shift extent records to the left to cover a hole.
- * RETURNS:
- *      0 on success
- *      errno on error
- *
+ * @next_fsb will keep track of the extent currently undergoing shift.
+ * @stop_fsb will keep track of the extent at which we have to stop.
+ * If we are shifting left, we will start with block (offset + len) and
+ * shift each extent till last extent.
+ * If we are shifting right, we will start with last extent inside file space
+ * and continue until we reach the block corresponding to offset.
  */
 int
-xfs_collapse_file_space(
-        struct xfs_inode        *ip,
-        xfs_off_t               offset,
-        xfs_off_t               len)
+xfs_shift_file_space(
+        struct xfs_inode        *ip,
+        xfs_off_t               offset,
+        xfs_off_t               len,
+        enum shift_direction    direction)
 {
         int                     done = 0;
         struct xfs_mount        *mp = ip->i_mount;
@@ -1400,21 +1397,26 @@ xfs_collapse_file_space(
         struct xfs_bmap_free    free_list;
         xfs_fsblock_t           first_block;
         int                     committed;
-        xfs_fileoff_t           start_fsb;
+        xfs_fileoff_t           stop_fsb;
         xfs_fileoff_t           next_fsb;
         xfs_fileoff_t           shift_fsb;
 
-        ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL));
+        ASSERT(direction == SHIFT_LEFT || direction == SHIFT_RIGHT);
 
-        trace_xfs_collapse_file_space(ip);
+        if (direction == SHIFT_LEFT) {
+                next_fsb = XFS_B_TO_FSB(mp, offset + len);
+                stop_fsb = XFS_B_TO_FSB(mp, VFS_I(ip)->i_size);
+        } else {
+                /*
+                 * If right shift, delegate the work of initialization of
+                 * next_fsb to xfs_bmap_shift_extent as it has ilock held.
+                 */
+                next_fsb = NULLFSBLOCK;
+                stop_fsb = XFS_B_TO_FSB(mp, offset);
+        }
 
-        next_fsb = XFS_B_TO_FSB(mp, offset + len);
         shift_fsb = XFS_B_TO_FSB(mp, len);
 
-        error = xfs_free_file_space(ip, offset, len);
-        if (error)
-                return error;
-
         /*
          * Trim eofblocks to avoid shifting uninitialized post-eof preallocation
          * into the accessible region of the file.
@@ -1427,20 +1429,28 @@ xfs_collapse_file_space(
 
         /*
          * Writeback and invalidate cache for the remainder of the file as we're
-         * about to shift down every extent from the collapse range to EOF. The
-         * free of the collapse range above might have already done some of
-         * this, but we shouldn't rely on it to do anything outside of the range
-         * that was freed.
+         * about to shift down every extent from offset to EOF.
          */
         error = filemap_write_and_wait_range(VFS_I(ip)->i_mapping,
-                                             offset + len, -1);
+                                             offset, -1);
         if (error)
                 return error;
         error = invalidate_inode_pages2_range(VFS_I(ip)->i_mapping,
-                                        (offset + len) >> PAGE_CACHE_SHIFT, -1);
+                                        offset >> PAGE_CACHE_SHIFT, -1);
         if (error)
                 return error;
 
+        /*
+         * The extent shiting code works on extent granularity. So, if
+         * stop_fsb is not the starting block of extent, we need to split
+         * the extent at stop_fsb.
+         */
+        if (direction == SHIFT_RIGHT) {
+                error = xfs_bmap_split_extent(ip, stop_fsb);
+                if (error)
+                        return error;
+        }
+
         while (!error && !done) {
                 tp = xfs_trans_alloc(mp, XFS_TRANS_DIOSTRAT);
                 /*
@@ -1464,7 +1474,7 @@ xfs_collapse_file_space(
                 if (error)
                         goto out;
 
-                xfs_trans_ijoin(tp, ip, 0);
+                xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
 
                 xfs_bmap_init(&free_list, &first_block);
 
@@ -1472,10 +1482,9 @@ xfs_collapse_file_space(
                  * We are using the write transaction in which max 2 bmbt
                  * updates are allowed
                  */
-                start_fsb = next_fsb;
-                error = xfs_bmap_shift_extents(tp, ip, start_fsb, shift_fsb,
-                                &done, &next_fsb, &first_block, &free_list,
-                                XFS_BMAP_MAX_SHIFT_EXTENTS);
+                error = xfs_bmap_shift_extents(tp, ip, &next_fsb, shift_fsb,
+                                &done, stop_fsb, &first_block, &free_list,
+                                direction, XFS_BMAP_MAX_SHIFT_EXTENTS);
                 if (error)
                         goto out;
 
@@ -1484,18 +1493,70 @@ xfs_collapse_file_space(
                         goto out;
 
                 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
-                xfs_iunlock(ip, XFS_ILOCK_EXCL);
         }
 
         return error;
 
 out:
         xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT);
-        xfs_iunlock(ip, XFS_ILOCK_EXCL);
         return error;
 }
 
 /*
+ * xfs_collapse_file_space()
+ *      This routine frees disk space and shift extent for the given file.
+ *      The first thing we do is to free data blocks in the specified range
+ *      by calling xfs_free_file_space(). It would also sync dirty data
+ *      and invalidate page cache over the region on which collapse range
+ *      is working. And Shift extent records to the left to cover a hole.
+ * RETURNS:
+ *      0 on success
+ *      errno on error
+ *
+ */
+int
+xfs_collapse_file_space(
+        struct xfs_inode        *ip,
+        xfs_off_t               offset,
+        xfs_off_t               len)
+{
+        int error;
+
+        ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL));
+        trace_xfs_collapse_file_space(ip);
+
+        error = xfs_free_file_space(ip, offset, len);
+        if (error)
+                return error;
+
+        return xfs_shift_file_space(ip, offset, len, SHIFT_LEFT);
+}
+
+/*
+ * xfs_insert_file_space()
+ *      This routine create hole space by shifting extents for the given file.
+ *      The first thing we do is to sync dirty data and invalidate page cache
+ *      over the region on which insert range is working. And split an extent
+ *      to two extents at given offset by calling xfs_bmap_split_extent.
+ *      And shift all extent records which are laying between [offset,
+ *      last allocated extent] to the right to reserve hole range.
+ * RETURNS:
+ *      0 on success
+ *      errno on error
+ */
+int
+xfs_insert_file_space(
+        struct xfs_inode        *ip,
+        loff_t                  offset,
+        loff_t                  len)
+{
+        ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL));
+        trace_xfs_insert_file_space(ip);
+
+        return xfs_shift_file_space(ip, offset, len, SHIFT_RIGHT);
+}
+
+/*
  * We need to check that the format of the data fork in the temporary inode is
  * valid for the target inode before doing the swap. This is not a problem with
  * attr1 because of the fixed fork offset, but attr2 has a dynamically sized
diff --git a/fs/xfs/xfs_bmap_util.h b/fs/xfs/xfs_bmap_util.h
index 736429a72a12..af97d9a1dfb4 100644
--- a/fs/xfs/xfs_bmap_util.h
+++ b/fs/xfs/xfs_bmap_util.h
@@ -63,6 +63,8 @@ int	xfs_zero_file_space(struct xfs_inode *ip, xfs_off_t offset,
                             xfs_off_t len);
 int     xfs_collapse_file_space(struct xfs_inode *, xfs_off_t offset,
                                 xfs_off_t len);
+int     xfs_insert_file_space(struct xfs_inode *, xfs_off_t offset,
+                                xfs_off_t len);
 
 /* EOF block manipulation functions */
 bool    xfs_can_free_eofblocks(struct xfs_inode *ip, bool force);
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index ce615d12fb44..edeaccc7961a 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -816,6 +816,11 @@ xfs_file_write_iter(
         return ret;
 }
 
+#define XFS_FALLOC_FL_SUPPORTED                                         \
+                (FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |           \
+                 FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE |      \
+                 FALLOC_FL_INSERT_RANGE)
+
 STATIC long
 xfs_file_fallocate(
         struct file             *file,
@@ -829,11 +834,11 @@ xfs_file_fallocate(
         enum xfs_prealloc_flags flags = 0;
         uint                    iolock = XFS_IOLOCK_EXCL;
         loff_t                  new_size = 0;
+        bool                    do_file_insert = 0;
 
         if (!S_ISREG(inode->i_mode))
                 return -EINVAL;
-        if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |
-                     FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE))
+        if (mode & ~XFS_FALLOC_FL_SUPPORTED)
                 return -EOPNOTSUPP;
 
         xfs_ilock(ip, iolock);
@@ -867,6 +872,27 @@ xfs_file_fallocate(
                 error = xfs_collapse_file_space(ip, offset, len);
                 if (error)
                         goto out_unlock;
+        } else if (mode & FALLOC_FL_INSERT_RANGE) {
+                unsigned blksize_mask = (1 << inode->i_blkbits) - 1;
+
+                new_size = i_size_read(inode) + len;
+                if (offset & blksize_mask || len & blksize_mask) {
+                        error = -EINVAL;
+                        goto out_unlock;
+                }
+
+                /* check the new inode size does not wrap through zero */
+                if (new_size > inode->i_sb->s_maxbytes) {
+                        error = -EFBIG;
+                        goto out_unlock;
+                }
+
+                /* Offset should be less than i_size */
+                if (offset >= i_size_read(inode)) {
+                        error = -EINVAL;
+                        goto out_unlock;
+                }
+                do_file_insert = 1;
         } else {
                 flags |= XFS_PREALLOC_SET;
 
@@ -901,8 +927,19 @@ xfs_file_fallocate(
                 iattr.ia_valid = ATTR_SIZE;
                 iattr.ia_size = new_size;
                 error = xfs_setattr_size(ip, &iattr);
+                if (error)
+                        goto out_unlock;
         }
 
+        /*
+         * Perform hole insertion now that the file size has been
+         * updated so that if we crash during the operation we don't
+         * leave shifted extents past EOF and hence losing access to
+         * the data that is contained within them.
+         */
+        if (do_file_insert)
+                error = xfs_insert_file_space(ip, offset, len);
+
 out_unlock:
         xfs_iunlock(ip, iolock);
         return error;
diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h
index 51372e34d988..7e45fa155ea8 100644
--- a/fs/xfs/xfs_trace.h
+++ b/fs/xfs/xfs_trace.h
@@ -664,6 +664,7 @@ DEFINE_INODE_EVENT(xfs_alloc_file_space);
 DEFINE_INODE_EVENT(xfs_free_file_space);
 DEFINE_INODE_EVENT(xfs_zero_file_space);
 DEFINE_INODE_EVENT(xfs_collapse_file_space);
+DEFINE_INODE_EVENT(xfs_insert_file_space);
 DEFINE_INODE_EVENT(xfs_readdir);
 #ifdef CONFIG_XFS_POSIX_ACL
 DEFINE_INODE_EVENT(xfs_get_acl);