The patch below does not apply to the 6.3-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.3.y
git checkout FETCH_HEAD
git cherry-pick -x fd4aed8d985a3236d0877ff6d0c80ad39d4ce81a
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2023070420-fraction-such-da8d@gregkh' --subject-prefix 'PATCH 6.3.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From fd4aed8d985a3236d0877ff6d0c80ad39d4ce81a Mon Sep 17 00:00:00 2001
From: Mike Kravetz <mike.kravetz(a)oracle.com>
Date: Wed, 21 Jun 2023 14:24:03 -0700
Subject: [PATCH] hugetlb: revert use of page_cache_next_miss()
Ackerley Tng reported an issue with hugetlbfs fallocate as noted in the
Closes tag. The issue showed up after the conversion of hugetlb page
cache lookup code to use page_cache_next_miss. User visible effects are:
- hugetlbfs fallocate incorrectly returns -EEXIST if pages are presnet
in the file.
- hugetlb pages will not be included in core dumps if they need to be
brought in via GUP.
- userfaultfd UFFDIO_COPY will not notice pages already present in the
cache. It may try to allocate a new page and potentially return
ENOMEM as opposed to EEXIST.
Revert the use page_cache_next_miss() in hugetlb code.
IMPORTANT NOTE FOR STABLE BACKPORTS:
This patch will apply cleanly to v6.3. However, due to the change of
filemap_get_folio() return values, it will not function correctly. This
patch must be modified for stable backports.
[dan.carpenter(a)linaro.org: fix hugetlbfs_pagecache_present()]
Link: https://lkml.kernel.org/r/efa86091-6a2c-4064-8f55-9b44e1313015@moroto.mount…
Link: https://lkml.kernel.org/r/20230621212403.174710-2-mike.kravetz@oracle.com
Fixes: d0ce0e47b323 ("mm/hugetlb: convert hugetlb fault paths to use alloc_hugetlb_folio()")
Signed-off-by: Mike Kravetz <mike.kravetz(a)oracle.com>
Signed-off-by: Dan Carpenter <dan.carpenter(a)linaro.org>
Reported-by: Ackerley Tng <ackerleytng(a)google.com>
Closes: https://lore.kernel.org/linux-mm/cover.1683069252.git.ackerleytng@google.com
Reviewed-by: Sidhartha Kumar <sidhartha.kumar(a)oracle.com>
Cc: Erdem Aktas <erdemaktas(a)google.com>
Cc: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
Cc: Matthew Wilcox <willy(a)infradead.org>
Cc: Muchun Song <songmuchun(a)bytedance.com>
Cc: Vishal Annapurve <vannapurve(a)google.com>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index 90361a922cec..7b17ccfa039d 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -821,7 +821,6 @@ static long hugetlbfs_fallocate(struct file *file, int mode, loff_t offset,
*/
struct folio *folio;
unsigned long addr;
- bool present;
cond_resched();
@@ -842,10 +841,9 @@ static long hugetlbfs_fallocate(struct file *file, int mode, loff_t offset,
mutex_lock(&hugetlb_fault_mutex_table[hash]);
/* See if already present in mapping to avoid alloc/free */
- rcu_read_lock();
- present = page_cache_next_miss(mapping, index, 1) != index;
- rcu_read_unlock();
- if (present) {
+ folio = filemap_get_folio(mapping, index);
+ if (!IS_ERR(folio)) {
+ folio_put(folio);
mutex_unlock(&hugetlb_fault_mutex_table[hash]);
continue;
}
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index d76574425da3..bce28cca73a1 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -5728,13 +5728,13 @@ static bool hugetlbfs_pagecache_present(struct hstate *h,
{
struct address_space *mapping = vma->vm_file->f_mapping;
pgoff_t idx = vma_hugecache_offset(h, vma, address);
- bool present;
-
- rcu_read_lock();
- present = page_cache_next_miss(mapping, idx, 1) != idx;
- rcu_read_unlock();
+ struct folio *folio;
- return present;
+ folio = filemap_get_folio(mapping, idx);
+ if (IS_ERR(folio))
+ return false;
+ folio_put(folio);
+ return true;
}
int hugetlb_add_to_page_cache(struct folio *folio, struct address_space *mapping,