Hello Sergey Bashirov,
Commit d84c4754f874 ("pNFS: Fix extent encoding in block/scsi
layout") from Jun 30, 2025 (linux-next), leads to the following
Smatch static checker warning:
fs/nfs/blocklayout/extent_tree.c:615 ext_tree_encode_commit()
error: uninitialized symbol 'be_prev'.
fs/nfs/blocklayout/extent_tree.c
584 static int
585 ext_tree_encode_commit(struct pnfs_block_layout *bl, __be32 *p,
586 size_t buffer_size, size_t *count, __u64 *lastbyte)
587 {
588 struct pnfs_block_extent *be, *be_prev;
589 int ret = 0;
590
591 spin_lock(&bl->bl_ext_lock);
592 for (be = ext_tree_first(&bl->bl_ext_rw); be; be = ext_tree_next(be)) {
593 if (be->be_state != PNFS_BLOCK_INVALID_DATA ||
594 be->be_tag != EXTENT_WRITTEN)
595 continue;
596
597 (*count)++;
598 if (ext_tree_layoutupdate_size(bl, *count) > buffer_size) {
599 (*count)--;
600 ret = -ENOSPC;
If we fail on the first iteration then be_prev is uninitialized.
601 break;
602 }
603
604 if (bl->bl_scsi_layout)
605 p = encode_scsi_range(be, p);
606 else
607 p = encode_block_extent(be, p);
608 be->be_tag = EXTENT_COMMITTING;
609 be_prev = be;
610 }
611 if (!ret) {
612 *lastbyte = (bl->bl_lwb != 0) ? bl->bl_lwb - 1 : U64_MAX;
613 bl->bl_lwb = 0;
614 } else {
--> 615 *lastbyte = be_prev->be_f_offset + be_prev->be_length;
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Dereferenced here.
616 *lastbyte <<= SECTOR_SHIFT;
617 *lastbyte -= 1;
618 }
619 spin_unlock(&bl->bl_ext_lock);
620
621 return ret;
622 }
regards,
dan carpenter
