}
return error;
}
+
+/*
+ * Shift extent records to the left to cover a hole.
+ *
+ * The maximum number of extents to be shifted in a single operation
+ * is @num_exts, and @current_ext keeps track of the current extent
+ * index we have shifted. @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 immediately.
+ */
+int
+xfs_bmap_shift_extents(
+ struct xfs_trans *tp,
+ struct xfs_inode *ip,
+ int *done,
+ xfs_fileoff_t start_fsb,
+ xfs_fileoff_t offset_shift_fsb,
+ xfs_extnum_t *current_ext,
+ xfs_fsblock_t *firstblock,
+ struct xfs_bmap_free *flist,
+ int num_exts)
+{
+ struct xfs_btree_cur *cur;
+ struct xfs_bmbt_rec_host *gotp;
+ struct xfs_bmbt_irec got;
+ struct xfs_bmbt_irec left;
+ struct xfs_mount *mp = ip->i_mount;
+ struct xfs_ifork *ifp;
+ xfs_extnum_t nexts = 0;
+ xfs_fileoff_t startoff;
+ int error = 0;
+ int i;
+ int whichfork = XFS_DATA_FORK;
+ int logflags;
+ xfs_filblks_t blockcount = 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_shift_extents",
+ XFS_ERRLEVEL_LOW, mp);
+ return XFS_ERROR(EFSCORRUPTED);
+ }
+
+ if (XFS_FORCED_SHUTDOWN(mp))
+ return XFS_ERROR(EIO);
+
+ ASSERT(current_ext != NULL);
+
+ 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;
+ }
+
+ /*
+ * If *current_ext is 0, we would need to lookup the extent
+ * from where we would start shifting and store it in gotp.
+ */
+ if (!*current_ext) {
+ gotp = xfs_iext_bno_to_ext(ifp, start_fsb, current_ext);
+ /*
+ * 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 way, we are done.
+ */
+ if (!gotp) {
+ *done = 1;
+ return 0;
+ }
+ }
+
+ /* We are going to change core inode */
+ logflags = XFS_ILOG_CORE;
+
+ if (ifp->if_flags & XFS_IFBROOT) {
+ cur = xfs_bmbt_init_cursor(mp, tp, ip, whichfork);
+ cur->bc_private.b.firstblock = *firstblock;
+ cur->bc_private.b.flist = flist;
+ cur->bc_private.b.flags = 0;
+ } else {
+ cur = NULL;
+ logflags |= XFS_ILOG_DEXT;
+ }
+
+ while (nexts++ < num_exts &&
+ *current_ext < XFS_IFORK_NEXTENTS(ip, whichfork)) {
+
+ gotp = xfs_iext_get_ext(ifp, *current_ext);
+ xfs_bmbt_get_all(gotp, &got);
+ startoff = got.br_startoff - offset_shift_fsb;
+
+ /*
+ * Before shifting extent into hole, make sure that the hole
+ * is large enough to accomodate the shift.
+ */
+ if (*current_ext) {
+ xfs_bmbt_get_all(xfs_iext_get_ext(ifp,
+ *current_ext - 1), &left);
+
+ if (startoff < left.br_startoff + left.br_blockcount)
+ error = XFS_ERROR(EINVAL);
+ } else if (offset_shift_fsb > got.br_startoff) {
+ /*
+ * When first extent is shifted, offset_shift_fsb
+ * should be less than the stating offset of
+ * the first extent.
+ */
+ error = XFS_ERROR(EINVAL);
+ }
+
+ if (error)
+ goto del_cursor;
+
+ if (cur) {
+ 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(i == 1, del_cursor);
+ }
+
+ /* Check if we can merge 2 adjacent extents */
+ if (*current_ext &&
+ left.br_startoff + left.br_blockcount == startoff &&
+ left.br_startblock + left.br_blockcount ==
+ got.br_startblock &&
+ left.br_state == got.br_state &&
+ left.br_blockcount + got.br_blockcount <= MAXEXTLEN) {
+ blockcount = left.br_blockcount +
+ got.br_blockcount;
+ xfs_iext_remove(ip, *current_ext, 1, 0);
+ if (cur) {
+ error = xfs_btree_delete(cur, &i);
+ if (error)
+ goto del_cursor;
+ XFS_WANT_CORRUPTED_GOTO(i == 1, del_cursor);
+ }
+ XFS_IFORK_NEXT_SET(ip, whichfork,
+ XFS_IFORK_NEXTENTS(ip, whichfork) - 1);
+ gotp = xfs_iext_get_ext(ifp, --*current_ext);
+ xfs_bmbt_get_all(gotp, &got);
+
+ /* Make cursor point to the extent we will update */
+ if (cur) {
+ 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(i == 1, del_cursor);
+ }
+
+ xfs_bmbt_set_blockcount(gotp, blockcount);
+ got.br_blockcount = blockcount;
+ } else {
+ /* We have to update the startoff */
+ xfs_bmbt_set_startoff(gotp, startoff);
+ got.br_startoff = startoff;
+ }
+
+ if (cur) {
+ error = xfs_bmbt_update(cur, got.br_startoff,
+ got.br_startblock,
+ got.br_blockcount,
+ got.br_state);
+ if (error)
+ goto del_cursor;
+ }
+
+ (*current_ext)++;
+ }
+
+ /* Check if we are done */
+ if (*current_ext == XFS_IFORK_NEXTENTS(ip, whichfork))
+ *done = 1;
+
+del_cursor:
+ if (cur)
+ xfs_btree_del_cursor(cur,
+ error ? XFS_BTREE_ERROR : XFS_BTREE_NOERROR);
+
+ xfs_trans_log_inode(tp, ip, logflags);
+
+ return error;
+}
projects / cascardo / linux.git / blobdiff