Move the check that the inode really is a shmemfs one from shmem_read_folio_gfp to shmem_get_folio_gfp given that shmem_get_folio can also be called from outside of shmem.c. Also turn it into a WARN_ON_ONCE and error return instead of BUG_ON to be less severe. Signed-off-by: Christoph Hellwig <hch@xxxxxx> Reviewed-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Reviewed-by: Darrick J. Wong <djwong@xxxxxxxxxx> --- mm/shmem.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/mm/shmem.c b/mm/shmem.c index 1900916aa84d13..ad533b2f0721a7 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1972,6 +1972,9 @@ static int shmem_get_folio_gfp(struct inode *inode, pgoff_t index, int error; bool alloced; + if (WARN_ON_ONCE(!shmem_mapping(inode->i_mapping))) + return -EINVAL; + if (index > (MAX_LFS_FILESIZE >> PAGE_SHIFT)) return -EFBIG; repeat: @@ -4915,7 +4918,6 @@ struct folio *shmem_read_folio_gfp(struct address_space *mapping, struct folio *folio; int error; - BUG_ON(!shmem_mapping(mapping)); error = shmem_get_folio_gfp(inode, index, &folio, SGP_CACHE, gfp, NULL, NULL); if (error) -- 2.39.2
