Merge branch 'fallocate-insert-range' into for-next

2 files changed, 323 insertions, 46 deletions

diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index b872e9cedb69..aeffeaaac0ec 100644
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -5486,52 +5486,92 @@ 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) {
@@ -5547,14 +5587,14 @@ 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
@@ -5564,12 +5604,13 @@ 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;
@@ -5579,10 +5620,11 @@ 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 &&
@@ -5598,6 +5640,8 @@ 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)) {
@@ -5615,43 +5659,83 @@ 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;
 	}
@@ -5666,3 +5750,189 @@ 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__ */