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nilfs2: eliminate staggered calls to kunmap in nilfs_rename

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In nilfs_rename(), calls to nilfs_put_page() to release pages obtained
with nilfs_find_entry() or nilfs_dotdot() are alternated in the normal
path.

When replacing the kernel memory mapping method from kmap to
kmap_local_{page,folio}, this violates the constraint on the calling order
of kunmap_local().

Swap the order of nilfs_put_page calls where the kmap sections of multiple
pages overlap so that they are nested, allowing direct replacement of
nilfs_put_page() -> unmap_and_put_page().

Without this reordering, that replacement will cause a kernel WARNING in
kunmap_local_indexed() on architectures with high memory mapping.

Link: https://lkml.kernel.org/r/20231127143036.2425-3-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Ryusuke Konishi 2023-11-27 23:30:21 +09:00 committed by Andrew Morton
parent 584db20c18
commit 8cf57c6df8
1 changed files with 2 additions and 1 deletions
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3
fs/nilfs2/namei.c
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@ -411,13 +411,14 @@ static int nilfs_rename(struct mnt_idmap *idmap,
inode_set_ctime_current(old_inode);
nilfs_delete_entry(old_de, old_page);
nilfs_put_page(old_page);
if (dir_de) {
nilfs_set_link(old_inode, dir_de, dir_page, new_dir);
nilfs_put_page(dir_page);
drop_nlink(old_dir);
}
nilfs_put_page(old_page);
nilfs_mark_inode_dirty(old_dir);
nilfs_mark_inode_dirty(old_inode);