在 2024/7/13 16:45, Zhang Yi 写道:
hulk inclusion category: perf bugzilla: https://gitee.com/openeuler/kernel/issues/IACNS4 CVE: NA
Now we allocate ifs if i_blocks_per_folio is larger than one when writing back dirty folios in iomap_writepage_map(), so we don't attach an ifs after buffer write to an entire folio until it starts writing back, if we partial truncate that folio, iomap_invalidate_folio() can't clear counterpart block's dirty bit as expected. Fix this by advance the ifs allocation to __iomap_write_begin().
Signed-off-by: Zhang Yi yi.zhang@huawei.com
fs/iomap/buffered-io.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-)
diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index 41185c7d4e7c..e76b79efc0df 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -682,6 +682,12 @@ int __iomap_write_begin(const struct iomap_iter *iter, loff_t pos, size_t from = offset_in_folio(folio, pos), to = from + len; size_t poff, plen;
- if (nr_blocks > 1) {
ifs = ifs_alloc(iter->inode, folio, iter->flags);if ((iter->flags & IOMAP_NOWAIT) && !ifs)return -EAGAIN;- }
- /*
- If the write or zeroing completely overlaps the current folio, then
- entire folio will be dirtied so there is no need for
@@ -693,10 +699,6 @@ int __iomap_write_begin(const struct iomap_iter *iter, loff_t pos, pos + len >= folio_pos(folio) + folio_size(folio)) return 0;
- ifs = ifs_alloc(iter->inode, folio, iter->flags);
- if ((iter->flags & IOMAP_NOWAIT) && !ifs && nr_blocks > 1)
return -EAGAIN;- if (folio_test_uptodate(folio)) return 0; folio_clear_error(folio);
@@ -1925,7 +1927,12 @@ static int iomap_writepage_map(struct iomap_writepage_ctx *wpc, WARN_ON_ONCE(end_pos <= pos);
if (i_blocks_per_folio(inode, folio) > 1) {
if (!ifs) {
/** This should not happen since we always allocate ifs in* iomap_folio_mkwrite_iter() and there is more than one* blocks per folio in __iomap_write_begin().*/if (WARN_ON_ONCE(!ifs)) {
page mkwrite流程里怎么保证的？
ifs = ifs_alloc(inode, folio, 0); iomap_set_range_dirty(folio, 0, end_pos - pos); }