diff options
Diffstat (limited to 'fs/xfs/xfs_bmap.c')
| -rw-r--r-- | fs/xfs/xfs_bmap.c | 193 |
1 files changed, 193 insertions, 0 deletions
diff --git a/fs/xfs/xfs_bmap.c b/fs/xfs/xfs_bmap.c index 152543c4ca70..5b6092ef51ef 100644 --- a/fs/xfs/xfs_bmap.c +++ b/fs/xfs/xfs_bmap.c @@ -5378,3 +5378,196 @@ error0: } 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; +} |