ext4: warn when page is dirtied without buffers

Warn when a page is dirtied without buffers (as that will likely lead to
a crash in ext4_writepages()) or when it gets newly dirtied without the
page being locked (as there is nothing that prevents buffers to get
stripped just before calling set_page_dirty() under memory pressure).

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
This commit is contained in:
Jan Kara 2016-12-01 11:46:40 -05:00 committed by Theodore Ts'o
parent d14e7683ec
commit 6dcc693bc5

View File

@ -3714,6 +3714,13 @@ static int ext4_journalled_set_page_dirty(struct page *page)
return __set_page_dirty_nobuffers(page); return __set_page_dirty_nobuffers(page);
} }
static int ext4_set_page_dirty(struct page *page)
{
WARN_ON_ONCE(!PageLocked(page) && !PageDirty(page));
WARN_ON_ONCE(!page_has_buffers(page));
return __set_page_dirty_buffers(page);
}
static const struct address_space_operations ext4_aops = { static const struct address_space_operations ext4_aops = {
.readpage = ext4_readpage, .readpage = ext4_readpage,
.readpages = ext4_readpages, .readpages = ext4_readpages,
@ -3721,6 +3728,7 @@ static const struct address_space_operations ext4_aops = {
.writepages = ext4_writepages, .writepages = ext4_writepages,
.write_begin = ext4_write_begin, .write_begin = ext4_write_begin,
.write_end = ext4_write_end, .write_end = ext4_write_end,
.set_page_dirty = ext4_set_page_dirty,
.bmap = ext4_bmap, .bmap = ext4_bmap,
.invalidatepage = ext4_invalidatepage, .invalidatepage = ext4_invalidatepage,
.releasepage = ext4_releasepage, .releasepage = ext4_releasepage,
@ -3753,6 +3761,7 @@ static const struct address_space_operations ext4_da_aops = {
.writepages = ext4_writepages, .writepages = ext4_writepages,
.write_begin = ext4_da_write_begin, .write_begin = ext4_da_write_begin,
.write_end = ext4_da_write_end, .write_end = ext4_da_write_end,
.set_page_dirty = ext4_set_page_dirty,
.bmap = ext4_bmap, .bmap = ext4_bmap,
.invalidatepage = ext4_da_invalidatepage, .invalidatepage = ext4_da_invalidatepage,
.releasepage = ext4_releasepage, .releasepage = ext4_releasepage,