The patch titled
Subject: shmem: shmem_get_partial_folio use filemap_get_entry
has been added to the -mm mm-unstable branch. Its filename is
shmem-shmem_get_partial_folio-use-filemap_get_entry.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/shmem-shmem_get_partial_folio-use-filemap_get_entry.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Hugh Dickins <hughd@xxxxxxxxxx>
Subject: shmem: shmem_get_partial_folio use filemap_get_entry
Date: Sun, 19 Mar 2023 22:19:21 -0700 (PDT)
To avoid use of the FGP_ENTRY flag, adapt shmem_get_partial_folio() to use
filemap_get_entry() and folio_lock() instead of __filemap_get_folio().
Update "page" in the comments there to "folio".
Link: https://lkml.kernel.org/r/9d1aaa4-1337-fb81-6f37-74ebc96f9ef@xxxxxxxxxx
Signed-off-by: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Andreas Gruenbacher <agruenba@xxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Ryusuke Konishi <konishi.ryusuke@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
--- a/mm/shmem.c~shmem-shmem_get_partial_folio-use-filemap_get_entry
+++ a/mm/shmem.c
@@ -886,14 +886,21 @@ static struct folio *shmem_get_partial_f
/*
* At first avoid shmem_get_folio(,,,SGP_READ): that fails
- * beyond i_size, and reports fallocated pages as holes.
+ * beyond i_size, and reports fallocated folios as holes.
*/
- folio = __filemap_get_folio(inode->i_mapping, index,
- FGP_ENTRY | FGP_LOCK, 0);
- if (!xa_is_value(folio))
+ folio = filemap_get_entry(inode->i_mapping, index);
+ if (!folio)
return folio;
+ if (!xa_is_value(folio)) {
+ folio_lock(folio);
+ if (folio->mapping == inode->i_mapping)
+ return folio;
+ /* The folio has been swapped out */
+ folio_unlock(folio);
+ folio_put(folio);
+ }
/*
- * But read a page back from swap if any of it is within i_size
+ * But read a folio back from swap if any of it is within i_size
* (although in some cases this is just a waste of time).
*/
folio = NULL;
_
Patches currently in -mm which might be from hughd@xxxxxxxxxx are
shmem-shmem_get_partial_folio-use-filemap_get_entry.patch
shmem-open-code-the-page-cache-lookup-in-shmem_get_folio_gfp-fix.patch
