6.1-stable review patch. If anyone has any objections, please let me know.
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From: Gao Xiang hsiangkao@linux.alibaba.com
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-4e9ff6c4dd53@pengutronix.d... Closes: https://lore.kernel.org/r/38d43fae-1182-4155-9c5b-ffc7382d9917@siemens.com Tested-by: Jan Kiszka jan.kiszka@siemens.com Tested-by: Stefan Kerkmann s.kerkmann@pengutronix.de Link: https://lore.kernel.org/r/20250709034614.2780117-2-hsiangkao@linux.alibaba.c... Signed-off-by: Gao Xiang hsiangkao@linux.alibaba.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/erofs/decompressor.c | 6 ++---- fs/erofs/zdata.c | 32 +++++++++++++++++++------------- 2 files changed, 21 insertions(+), 17 deletions(-)
--- a/fs/erofs/decompressor.c +++ b/fs/erofs/decompressor.c @@ -342,14 +342,12 @@ static int z_erofs_transform_plain(struc
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; --- a/fs/erofs/zdata.c +++ b/fs/erofs/zdata.c @@ -123,9 +123,11 @@ static inline unsigned int z_erofs_pclus
/* * 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) { @@ -144,7 +146,7 @@ static inline void z_erofs_onlinepage_sp 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;
@@ -152,16 +154,20 @@ static void z_erofs_onlinepage_endio(str
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 @@ -925,7 +931,7 @@ next_part: goto repeat;
out: - z_erofs_onlinepage_endio(page, err); + z_erofs_onlinepage_end(page, err, false); return err; }
@@ -1028,7 +1034,7 @@ static void z_erofs_fill_other_copies(st 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); } @@ -1196,7 +1202,7 @@ out: /* 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)