Hello Matthew Wilcox (Oracle),
The patch 2aadca213a3f: "ufs: add ufs_get_locked_folio and
ufs_put_locked_folio" from Oct 16, 2023 (linux-next), leads to the
following Smatch static checker warning:
fs/ufs/util.c:248 ufs_get_locked_folio() warn: 'folio' is an error pointer or valid
fs/ufs/util.c:266 ufs_get_locked_folio() error: 'folio' dereferencing possible ERR_PTR()
fs/ufs/util.c
243 struct folio *ufs_get_locked_folio(struct address_space *mapping,
244 pgoff_t index)
245 {
246 struct inode *inode = mapping->host;
247 struct folio *folio = filemap_lock_folio(mapping, index);
--> 248 if (!folio) {
Should this be if (!IS_ERR(folio)) {
249 folio = read_mapping_folio(mapping, index, NULL);
250
251 if (IS_ERR(folio)) {
252 printk(KERN_ERR "ufs_change_blocknr: read_mapping_folio error: ino %lu, index: %lu\n",
253 mapping->host->i_ino, index);
254 return folio;
255 }
256
257 folio_lock(folio);
258
259 if (unlikely(folio->mapping == NULL)) {
260 /* Truncate got there first */
261 folio_unlock(folio);
262 folio_put(folio);
263 return NULL;
264 }
265 }
266 if (!folio_buffers(folio))
^^^^^
267 create_empty_buffers(folio, 1 << inode->i_blkbits, 0);
268 return folio;
269 }
regards,
dan carpenter
