commit 27917e8194f91dffd8b4825350c63cb68e98ce58 upstream.
Flush the D-cache before unlocking folios for compressed inodes, as
they are dirtied during decompression.
Avoid calling flush_dcache_folio() on every CPU write, since it's more
like playing whack-a-mole without real benefit.
It has no impact on x86 and arm64/risc-v: on x86, flush_dcache_folio()
is a no-op, and on arm64/risc-v, PG_dcache_clean (PG_arch_1) is clear
for new page cache folios. However, certain ARM boards are affected,
as reported.
Fixes: 3883a79abd02 ("staging: erofs: introduce VLE decompression support")
Closes:
https://lore.kernel.org/r/c1e51e16-6cc6-49d0-a63e-4e9ff6c4d...@pengutronix.de
Closes:
https://lore.kernel.org/r/38d43fae-1182-4155-9c5b-ffc7382d9...@siemens.com
Tested-by: Jan Kiszka <jan.kis...@siemens.com>
Tested-by: Stefan Kerkmann <s.kerkm...@pengutronix.de>
Link:
https://lore.kernel.org/r/20250709034614.2780117-2-hsiang...@linux.alibaba.com
Signed-off-by: Gao Xiang <hsiang...@linux.alibaba.com>
---
Hi Jan & Stefan,
Please help confirm this 6.6 fix backport if possible.
Thanks,
Gao Xiang
fs/erofs/decompressor.c | 6 ++----
fs/erofs/zdata.c | 32 +++++++++++++++++++-------------
2 files changed, 21 insertions(+), 17 deletions(-)
diff --git a/fs/erofs/decompressor.c b/fs/erofs/decompressor.c
index aa59788a61e6..86e088fd386e 100644
--- a/fs/erofs/decompressor.c
+++ b/fs/erofs/decompressor.c
@@ -342,14 +342,12 @@ static int z_erofs_transform_plain(struct
z_erofs_decompress_req *rq,
if (outpages > inpages) {
DBG_BUGON(!rq->out[outpages - 1]);
- if (rq->out[outpages - 1] != rq->in[inpages - 1]) {
+ if (rq->out[outpages - 1] != rq->in[inpages - 1])
memcpy_to_page(rq->out[outpages - 1], 0, src +
(interlaced_offset ? 0 : righthalf),
lefthalf);
- } else if (!interlaced_offset) {
+ else if (!interlaced_offset)
memmove(src, src + righthalf, lefthalf);
- flush_dcache_page(rq->in[inpages - 1]);
- }
}
kunmap_local(src);
return 0;
diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
index 496e4c7c52a4..d852b43ac43e 100644
--- a/fs/erofs/zdata.c
+++ b/fs/erofs/zdata.c
@@ -122,9 +122,11 @@ static inline unsigned int z_erofs_pclusterpages(struct
z_erofs_pcluster *pcl)
/*
* bit 30: I/O error occurred on this page
+ * bit 29: CPU has dirty data in D-cache (needs aliasing handling);
* bit 0 - 29: remaining parts to complete this page
*/
-#define Z_EROFS_PAGE_EIO (1 << 30)
+#define Z_EROFS_ONLINEPAGE_EIO 30
+#define Z_EROFS_ONLINEPAGE_DIRTY 29
static inline void z_erofs_onlinepage_init(struct page *page)
{
@@ -143,7 +145,7 @@ static inline void z_erofs_onlinepage_split(struct page
*page)
atomic_inc((atomic_t *)&page->private);
}
-static void z_erofs_onlinepage_endio(struct page *page, int err)
+static void z_erofs_onlinepage_end(struct page *page, int err, bool dirty)
{
int orig, v;
@@ -151,16 +153,20 @@ static void z_erofs_onlinepage_endio(struct page *page,
int err)
do {
orig = atomic_read((atomic_t *)&page->private);
- v = (orig - 1) | (err ? Z_EROFS_PAGE_EIO : 0);
+ DBG_BUGON(orig <= 0);
+ v = dirty << Z_EROFS_ONLINEPAGE_DIRTY;
+ v |= (orig - 1) | (!!err << Z_EROFS_ONLINEPAGE_EIO);
} while (atomic_cmpxchg((atomic_t *)&page->private, orig, v) != orig);
- if (!(v & ~Z_EROFS_PAGE_EIO)) {
- set_page_private(page, 0);
- ClearPagePrivate(page);
- if (!(v & Z_EROFS_PAGE_EIO))
- SetPageUptodate(page);
- unlock_page(page);
- }
+ if (v & (BIT(Z_EROFS_ONLINEPAGE_DIRTY) - 1))
+ return;
+ set_page_private(page, 0);
+ ClearPagePrivate(page);
+ if (v & BIT(Z_EROFS_ONLINEPAGE_DIRTY))
+ flush_dcache_page(page);
+ if (!(v & BIT(Z_EROFS_ONLINEPAGE_EIO)))
+ SetPageUptodate(page);
+ unlock_page(page);
}
#define Z_EROFS_ONSTACK_PAGES 32
@@ -1060,7 +1066,7 @@ static int z_erofs_do_read_page(struct
z_erofs_decompress_frontend *fe,
goto repeat;
out:
- z_erofs_onlinepage_endio(page, err);
+ z_erofs_onlinepage_end(page, err, false);
return err;
}
@@ -1163,7 +1169,7 @@ static void z_erofs_fill_other_copies(struct
z_erofs_decompress_backend *be,
cur += len;
}
kunmap_local(dst);
- z_erofs_onlinepage_endio(bvi->bvec.page, err);
+ z_erofs_onlinepage_end(bvi->bvec.page, err, true);
list_del(p);
kfree(bvi);
}
@@ -1333,7 +1339,7 @@ static int z_erofs_decompress_pcluster(struct
z_erofs_decompress_backend *be,
/* recycle all individual short-lived pages */
if (z_erofs_put_shortlivedpage(be->pagepool, page))
continue;
- z_erofs_onlinepage_endio(page, err);
+ z_erofs_onlinepage_end(page, err, true);
}
if (be->decompressed_pages != be->onstack_pages)
--
2.43.5
