Re: [PATCH 18/24] mm/swap: introduce a helper non fault swapin
From: kernel test robot
Date: Sun Nov 19 2023 - 20:08:03 EST
Hi Kairui,
kernel test robot noticed the following build errors:
[auto build test ERROR on akpm-mm/mm-everything]
[also build test ERROR on linus/master v6.7-rc2 next-20231117]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Kairui-Song/mm-swap-fix-a-potential-undefined-behavior-issue/20231120-035926
base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link: https://lore.kernel.org/r/20231119194740.94101-19-ryncsn%40gmail.com
patch subject: [PATCH 18/24] mm/swap: introduce a helper non fault swapin
config: i386-buildonly-randconfig-002-20231120 (https://download.01.org/0day-ci/archive/20231120/202311200850.FrQj7bMD-lkp@xxxxxxxxx/config)
compiler: clang version 16.0.4 (https://github.com/llvm/llvm-project.git ae42196bc493ffe877a7e3dff8be32035dea4d07)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231120/202311200850.FrQj7bMD-lkp@xxxxxxxxx/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-kbuild-all/202311200850.FrQj7bMD-lkp@xxxxxxxxx/
All errors (new ones prefixed by >>):
In file included from mm/shmem.c:43:
mm/swap.h:105:31: warning: declaration of 'enum swap_cache_result' will not be visible outside of this function [-Wvisibility]
struct vm_fault *vmf, enum swap_cache_result *result)
^
mm/swap.h:112:8: warning: declaration of 'enum swap_cache_result' will not be visible outside of this function [-Wvisibility]
enum swap_cache_result *result)
^
>> mm/shmem.c:1841:25: error: variable has incomplete type 'enum swap_cache_result'
enum swap_cache_result result;
^
mm/shmem.c:1841:7: note: forward declaration of 'enum swap_cache_result'
enum swap_cache_result result;
^
>> mm/shmem.c:1870:31: error: use of undeclared identifier 'SWAP_CACHE_HIT'
if (fault_type && result != SWAP_CACHE_HIT) {
^
>> mm/shmem.c:1879:17: error: use of undeclared identifier 'SWAP_CACHE_BYPASS'
if ((result != SWAP_CACHE_BYPASS && !folio_test_swapcache(folio)) ||
^
2 warnings and 3 errors generated.
vim +1841 mm/shmem.c
1827
1828 /*
1829 * Swap in the folio pointed to by *foliop.
1830 * Caller has to make sure that *foliop contains a valid swapped folio.
1831 * Returns 0 and the folio in foliop if success. On failure, returns the
1832 * error code and NULL in *foliop.
1833 */
1834 static int shmem_swapin_folio(struct inode *inode, pgoff_t index,
1835 struct folio **foliop, enum sgp_type sgp,
1836 gfp_t gfp, struct mm_struct *fault_mm,
1837 vm_fault_t *fault_type)
1838 {
1839 struct address_space *mapping = inode->i_mapping;
1840 struct shmem_inode_info *info = SHMEM_I(inode);
> 1841 enum swap_cache_result result;
1842 struct folio *folio = NULL;
1843 struct mempolicy *mpol;
1844 struct page *page;
1845 swp_entry_t swap;
1846 pgoff_t ilx;
1847 int error;
1848
1849 VM_BUG_ON(!*foliop || !xa_is_value(*foliop));
1850 swap = radix_to_swp_entry(*foliop);
1851 *foliop = NULL;
1852
1853 if (is_poisoned_swp_entry(swap))
1854 return -EIO;
1855
1856 mpol = shmem_get_pgoff_policy(info, index, 0, &ilx);
1857 page = swapin_page_non_fault(swap, gfp, mpol, ilx, fault_mm, &result);
1858 mpol_cond_put(mpol);
1859
1860 if (PTR_ERR(page) == -EBUSY) {
1861 if (!shmem_confirm_swap(mapping, index, swap))
1862 return -EEXIST;
1863 else
1864 return -EINVAL;
1865 } else if (!page) {
1866 error = -ENOMEM;
1867 goto failed;
1868 } else {
1869 folio = page_folio(page);
> 1870 if (fault_type && result != SWAP_CACHE_HIT) {
1871 *fault_type |= VM_FAULT_MAJOR;
1872 count_vm_event(PGMAJFAULT);
1873 count_memcg_event_mm(fault_mm, PGMAJFAULT);
1874 }
1875 }
1876
1877 /* We have to do this with folio locked to prevent races */
1878 folio_lock(folio);
> 1879 if ((result != SWAP_CACHE_BYPASS && !folio_test_swapcache(folio)) ||
1880 folio->swap.val != swap.val ||
1881 !shmem_confirm_swap(mapping, index, swap)) {
1882 error = -EEXIST;
1883 goto unlock;
1884 }
1885 if (!folio_test_uptodate(folio)) {
1886 error = -EIO;
1887 goto failed;
1888 }
1889 folio_wait_writeback(folio);
1890
1891 /*
1892 * Some architectures may have to restore extra metadata to the
1893 * folio after reading from swap.
1894 */
1895 arch_swap_restore(swap, folio);
1896
1897 if (shmem_should_replace_folio(folio, gfp)) {
1898 error = shmem_replace_folio(&folio, gfp, info, index);
1899 if (error)
1900 goto failed;
1901 }
1902
1903 error = shmem_add_to_page_cache(folio, mapping, index,
1904 swp_to_radix_entry(swap), gfp);
1905 if (error)
1906 goto failed;
1907
1908 shmem_recalc_inode(inode, 0, -1);
1909
1910 if (sgp == SGP_WRITE)
1911 folio_mark_accessed(folio);
1912
1913 delete_from_swap_cache(folio);
1914 folio_mark_dirty(folio);
1915 swap_free(swap);
1916
1917 *foliop = folio;
1918 return 0;
1919 failed:
1920 if (!shmem_confirm_swap(mapping, index, swap))
1921 error = -EEXIST;
1922 if (error == -EIO)
1923 shmem_set_folio_swapin_error(inode, index, folio, swap);
1924 unlock:
1925 if (folio) {
1926 folio_unlock(folio);
1927 folio_put(folio);
1928 }
1929
1930 return error;
1931 }
1932
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki