On Wed 14-07-21 10:07:46, Ira Weiny wrote: > On Wed, Jul 14, 2021 at 06:54:48PM +0200, Javier Pello wrote: > > From: Javier Pello <javier.pello@xxxxxxx> > > > > Commit 782b76d7abdf02b12c46ed6f1e9bf715569027f7 ("fs/ext2: Replace > > kmap() with kmap_local_page()") replaced the kmap/kunmap calls in > > ext2_get_page/ext2_put_page with kmap_local_page/kunmap_local for > > efficiency reasons. As a necessary side change, the commit also > > made ext2_get_page (and ext2_find_entry and ext2_dotdot) return > > the mapping address along with the page itself, as it is required > > for kunmap_local, and converted uses of page_address on such pages > > to use the newly returned address instead. However, uses of > > page_address on such pages were missed in ext2_check_page and > > ext2_delete_entry, which triggers oopses if kmap_local_page happens > > to return an address from high memory. Fix this now by converting > > the remaining uses of page_address to use the right address, as > > returned by kmap_local_page. > > > > Again thanks for catching this! > > Reviewed-by: Ira Weiny <ira.weiny@xxxxxxxxx> Thanks for the patch and the review. I'de added the patch to my tree. Honza > > > Signed-off-by: Javier Pello <javier.pello@xxxxxxx> > > Fixes: 782b76d7abdf ("fs/ext2: Replace kmap() with kmap_local_page()") > > --- > > > > v2: Use char * for the new parameter to ext2_delete_entry. > > > > fs/ext2/dir.c | 12 ++++++------ > > fs/ext2/ext2.h | 3 ++- > > fs/ext2/namei.c | 4 ++-- > > 3 files changed, 10 insertions(+), 9 deletions(-) > > > > diff --git a/fs/ext2/dir.c b/fs/ext2/dir.c > > index 14292dba..2c2f179b 100644 > > --- a/fs/ext2/dir.c > > +++ b/fs/ext2/dir.c > > @@ -106,12 +106,11 @@ static int ext2_commit_chunk(struct page *page, loff_t pos, unsigned len) > > return err; > > } > > > > -static bool ext2_check_page(struct page *page, int quiet) > > +static bool ext2_check_page(struct page *page, int quiet, char *kaddr) > > { > > struct inode *dir = page->mapping->host; > > struct super_block *sb = dir->i_sb; > > unsigned chunk_size = ext2_chunk_size(dir); > > - char *kaddr = page_address(page); > > u32 max_inumber = le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count); > > unsigned offs, rec_len; > > unsigned limit = PAGE_SIZE; > > @@ -205,7 +204,8 @@ static struct page * ext2_get_page(struct inode *dir, unsigned long n, > > if (!IS_ERR(page)) { > > *page_addr = kmap_local_page(page); > > if (unlikely(!PageChecked(page))) { > > - if (PageError(page) || !ext2_check_page(page, quiet)) > > + if (PageError(page) || !ext2_check_page(page, quiet, > > + *page_addr)) > > goto fail; > > } > > } > > @@ -584,10 +584,10 @@ int ext2_add_link (struct dentry *dentry, struct inode *inode) > > * ext2_delete_entry deletes a directory entry by merging it with the > > * previous entry. Page is up-to-date. > > */ > > -int ext2_delete_entry (struct ext2_dir_entry_2 * dir, struct page * page ) > > +int ext2_delete_entry (struct ext2_dir_entry_2 *dir, struct page *page, > > + char *kaddr) > > { > > struct inode *inode = page->mapping->host; > > - char *kaddr = page_address(page); > > unsigned from = ((char*)dir - kaddr) & ~(ext2_chunk_size(inode)-1); > > unsigned to = ((char *)dir - kaddr) + > > ext2_rec_len_from_disk(dir->rec_len); > > @@ -607,7 +607,7 @@ int ext2_delete_entry (struct ext2_dir_entry_2 * dir, struct page * page ) > > de = ext2_next_entry(de); > > } > > if (pde) > > - from = (char*)pde - (char*)page_address(page); > > + from = (char *)pde - kaddr; > > pos = page_offset(page) + from; > > lock_page(page); > > err = ext2_prepare_chunk(page, pos, to - from); > > diff --git a/fs/ext2/ext2.h b/fs/ext2/ext2.h > > index b0a69482..e512630c 100644 > > --- a/fs/ext2/ext2.h > > +++ b/fs/ext2/ext2.h > > @@ -740,7 +740,8 @@ extern int ext2_inode_by_name(struct inode *dir, > > extern int ext2_make_empty(struct inode *, struct inode *); > > extern struct ext2_dir_entry_2 *ext2_find_entry(struct inode *, const struct qstr *, > > struct page **, void **res_page_addr); > > -extern int ext2_delete_entry (struct ext2_dir_entry_2 *, struct page *); > > +extern int ext2_delete_entry(struct ext2_dir_entry_2 *dir, struct page *page, > > + char *kaddr); > > extern int ext2_empty_dir (struct inode *); > > extern struct ext2_dir_entry_2 *ext2_dotdot(struct inode *dir, struct page **p, void **pa); > > extern void ext2_set_link(struct inode *, struct ext2_dir_entry_2 *, struct page *, void *, > > diff --git a/fs/ext2/namei.c b/fs/ext2/namei.c > > index 1f69b816..5f6b7560 100644 > > --- a/fs/ext2/namei.c > > +++ b/fs/ext2/namei.c > > @@ -293,7 +293,7 @@ static int ext2_unlink(struct inode * dir, struct dentry *dentry) > > goto out; > > } > > > > - err = ext2_delete_entry (de, page); > > + err = ext2_delete_entry (de, page, page_addr); > > ext2_put_page(page, page_addr); > > if (err) > > goto out; > > @@ -397,7 +397,7 @@ static int ext2_rename (struct user_namespace * mnt_userns, > > old_inode->i_ctime = current_time(old_inode); > > mark_inode_dirty(old_inode); > > > > - ext2_delete_entry(old_de, old_page); > > + ext2_delete_entry(old_de, old_page, old_page_addr); > > > > if (dir_de) { > > if (old_dir != new_dir) > > -- > > 2.30.1 -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR