- mp = ap->ip->i_mount;
- nullfb = ap->firstblock == NULLFSBLOCK;
- rt = XFS_IS_REALTIME_INODE(ap->ip) && ap->userdata;
- fb_agno = nullfb ? NULLAGNUMBER : XFS_FSB_TO_AGNO(mp, ap->firstblock);
-#ifdef __KERNEL__
- if (rt) {
- xfs_extlen_t extsz; /* file extent size for rt */
- xfs_fileoff_t nexto; /* next file offset */
- xfs_extlen_t orig_alen; /* original ap->alen */
- xfs_fileoff_t orig_end; /* original off+len */
- xfs_fileoff_t orig_off; /* original ap->off */
- xfs_extlen_t mod_off; /* modulus calculations */
- xfs_fileoff_t prevo; /* previous file offset */
- xfs_rtblock_t rtx; /* realtime extent number */
- xfs_extlen_t temp; /* temp for rt calculations */
+ if (!delay && !eof &&
+ (orig_off >= gotp->br_startoff) &&
+ (orig_end <= gotp->br_startoff + gotp->br_blockcount)) {
+ return 0;
+ }
+
+ /*
+ * If the file offset is unaligned vs. the extent size
+ * we need to align it. This will be possible unless
+ * the file was previously written with a kernel that didn't
+ * perform this alignment, or if a truncate shot us in the
+ * foot.
+ */
+ temp = do_mod(orig_off, extsz);
+ if (temp) {
+ align_alen += temp;
+ align_off -= temp;
+ }
+ /*
+ * Same adjustment for the end of the requested area.
+ */
+ if ((temp = (align_alen % extsz))) {
+ align_alen += extsz - temp;
+ }
+ /*
+ * If the previous block overlaps with this proposed allocation
+ * then move the start forward without adjusting the length.
+ */
+ if (prevp->br_startoff != NULLFILEOFF) {
+ if (prevp->br_startblock == HOLESTARTBLOCK)
+ prevo = prevp->br_startoff;
+ else
+ prevo = prevp->br_startoff + prevp->br_blockcount;
+ } else
+ prevo = 0;
+ if (align_off != orig_off && align_off < prevo)
+ align_off = prevo;
+ /*
+ * If the next block overlaps with this proposed allocation
+ * then move the start back without adjusting the length,
+ * but not before offset 0.
+ * This may of course make the start overlap previous block,
+ * and if we hit the offset 0 limit then the next block
+ * can still overlap too.
+ */
+ if (!eof && gotp->br_startoff != NULLFILEOFF) {
+ if ((delay && gotp->br_startblock == HOLESTARTBLOCK) ||
+ (!delay && gotp->br_startblock == DELAYSTARTBLOCK))
+ nexto = gotp->br_startoff + gotp->br_blockcount;
+ else
+ nexto = gotp->br_startoff;
+ } else
+ nexto = NULLFILEOFF;
+ if (!eof &&
+ align_off + align_alen != orig_end &&
+ align_off + align_alen > nexto)
+ align_off = nexto > align_alen ? nexto - align_alen : 0;
+ /*
+ * If we're now overlapping the next or previous extent that
+ * means we can't fit an extsz piece in this hole. Just move
+ * the start forward to the first valid spot and set
+ * the length so we hit the end.
+ */
+ if (align_off != orig_off && align_off < prevo)
+ align_off = prevo;
+ if (align_off + align_alen != orig_end &&
+ align_off + align_alen > nexto &&
+ nexto != NULLFILEOFF) {
+ ASSERT(nexto > prevo);
+ align_alen = nexto - align_off;
+ }