Hello Dave Chinner,
The patch 10634530f7ba: "xfs: convert kmem_zalloc() to kzalloc()"
from Jan 16, 2024 (linux-next), leads to the following Smatch static
checker warning:
fs/xfs/libxfs/xfs_btree_staging.c:416 xfs_btree_bload_prep_block()
error: potential null dereference 'ifp->if_broot'. (kzalloc returns null)
fs/xfs/libxfs/xfs_btree_staging.c
383 STATIC int
384 xfs_btree_bload_prep_block(
385 struct xfs_btree_cur *cur,
386 struct xfs_btree_bload *bbl,
387 struct list_head *buffers_list,
388 unsigned int level,
389 unsigned int nr_this_block,
390 union xfs_btree_ptr *ptrp, /* in/out */
391 struct xfs_buf **bpp, /* in/out */
392 struct xfs_btree_block **blockp, /* in/out */
393 void *priv)
394 {
395 union xfs_btree_ptr new_ptr;
396 struct xfs_buf *new_bp;
397 struct xfs_btree_block *new_block;
398 int ret;
399
400 if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
401 level == cur->bc_nlevels - 1) {
402 struct xfs_ifork *ifp = xfs_btree_ifork_ptr(cur);
403 size_t new_size;
404
405 ASSERT(*bpp == NULL);
406
407 /* Allocate a new incore btree root block. */
408 new_size = bbl->iroot_size(cur, level, nr_this_block, priv);
409 ifp->if_broot = kzalloc(new_size, GFP_KERNEL);
The rest of these were changed to GFP_KERNEL | __GFP_NOFAIL so I suspect
this was an oversight.
410 ifp->if_broot_bytes = (int)new_size;
411
412 /* Initialize it and send it out. */
413 xfs_btree_init_block_int(cur->bc_mp, ifp->if_broot,
414 XFS_BUF_DADDR_NULL, cur->bc_btnum, level,
415 nr_this_block, cur->bc_ino.ip->i_ino,
--> 416 cur->bc_flags);
417
418 *bpp = NULL;
419 *blockp = ifp->if_broot;
420 xfs_btree_set_ptr_null(cur, ptrp);
421 return 0;
422 }
regards,
dan carpenter
