[RFC PATCH 4/9] shmem: exit shmem_get_folio_gfp() if block is uptodate

Daniel Gomez
2024-02-09T14:29:27Z

When we get a folio from the page cache with filemap_get_entry() and
is uptodate we exit from shmem_get_folio_gfp(). Replicate the same
behaviour if the block is uptodate in the index we are operating on.

Signed-off-by: Daniel Gomez <da.gomez@samsung.com>
---
mm/shmem.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/mm/shmem.c b/mm/shmem.c
index 3bddf7a89c18..614cda767298 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -256,6 +256,16 @@ static inline bool shmem_is_any_uptodate(struct folio *folio)
return folio_test_uptodate(folio);
}

+static inline bool shmem_is_block_uptodate(struct folio *folio,
+ unsigned int block)
+{
+ struct shmem_folio_state *sfs = folio->private;
+
+ if (folio_test_large(folio) && sfs)
+ return sfs_is_block_uptodate(sfs, block);
+ return folio_test_uptodate(folio);
+}
+
static void shmem_set_range_uptodate(struct folio *folio, size_t off,
size_t len)
{
@@ -2143,7 +2153,7 @@ static int shmem_get_folio_gfp(struct inode *inode, pgoff_t index,
}
if (sgp == SGP_WRITE)
folio_mark_accessed(folio);
- if (folio_test_uptodate(folio))
+ if (shmem_is_block_uptodate(folio, index - folio_index(folio)))
goto out;
/* fallocated folio */
if (sgp != SGP_READ)
--
2.43.0