From: Eric Biggers <ebiggers(a)google.com>
f2fs didn't properly clean up if verity failed to be enabled on a file:
- It left verity metadata (pages past EOF) in the page cache, which
would be exposed to userspace if the file was later extended.
- It didn't truncate the verity metadata at all (either from cache or
from disk) if an error occurred while setting the verity bit.
Fix these bugs by adding a call to truncate_inode_pages() and ensuring
that we truncate the verity metadata (both from cache and from disk) in
all error paths. Also rework the code to cleanly separate the success
path from the error paths, which makes it much easier to understand.
Reported-by: Yunlei He <heyunlei(a)hihonor.com>
Fixes: 95ae251fe828 ("f2fs: add fs-verity support")
Cc: <stable(a)vger.kernel.org> # v5.4+
Signed-off-by: Eric Biggers <ebiggers(a)google.com>
---
fs/f2fs/verity.c | 61 ++++++++++++++++++++++++++++++++----------------
1 file changed, 41 insertions(+), 20 deletions(-)
diff --git a/fs/f2fs/verity.c b/fs/f2fs/verity.c
index 054ec852b5ea4..2db89967fde37 100644
--- a/fs/f2fs/verity.c
+++ b/fs/f2fs/verity.c
@@ -160,31 +160,52 @@ static int f2fs_end_enable_verity(struct file *filp, const void *desc,
};
int err = 0;
- if (desc != NULL) {
- /* Succeeded; write the verity descriptor. */
- err = pagecache_write(inode, desc, desc_size, desc_pos);
+ /*
+ * If an error already occurred (which fs/verity/ signals by passing
+ * desc == NULL), then only clean-up is needed.
+ */
+ if (desc == NULL)
+ goto cleanup;
- /* Write all pages before clearing FI_VERITY_IN_PROGRESS. */
- if (!err)
- err = filemap_write_and_wait(inode->i_mapping);
- }
+ /* Append the verity descriptor. */
+ err = pagecache_write(inode, desc, desc_size, desc_pos);
+ if (err)
+ goto cleanup;
- /* If we failed, truncate anything we wrote past i_size. */
- if (desc == NULL || err)
- f2fs_truncate(inode);
+ /*
+ * Write all pages (both data and verity metadata). Note that this must
+ * happen before clearing FI_VERITY_IN_PROGRESS; otherwise pages beyond
+ * i_size won't be written properly. For crash consistency, this also
+ * must happen before the verity inode flag gets persisted.
+ */
+ err = filemap_write_and_wait(inode->i_mapping);
+ if (err)
+ goto cleanup;
+
+ /* Set the verity xattr. */
+ err = f2fs_setxattr(inode, F2FS_XATTR_INDEX_VERITY,
+ F2FS_XATTR_NAME_VERITY, &dloc, sizeof(dloc),
+ NULL, XATTR_CREATE);
+ if (err)
+ goto cleanup;
+
+ /* Finally, set the verity inode flag. */
+ file_set_verity(inode);
+ f2fs_set_inode_flags(inode);
+ f2fs_mark_inode_dirty_sync(inode, true);
clear_inode_flag(inode, FI_VERITY_IN_PROGRESS);
+ return 0;
- if (desc != NULL && !err) {
- err = f2fs_setxattr(inode, F2FS_XATTR_INDEX_VERITY,
- F2FS_XATTR_NAME_VERITY, &dloc, sizeof(dloc),
- NULL, XATTR_CREATE);
- if (!err) {
- file_set_verity(inode);
- f2fs_set_inode_flags(inode);
- f2fs_mark_inode_dirty_sync(inode, true);
- }
- }
+cleanup:
+ /*
+ * Verity failed to be enabled, so clean up by truncating any verity
+ * metadata that was written beyond i_size (both from cache and from
+ * disk) and clearing FI_VERITY_IN_PROGRESS.
+ */
+ truncate_inode_pages(inode->i_mapping, inode->i_size);
+ f2fs_truncate(inode);
+ clear_inode_flag(inode, FI_VERITY_IN_PROGRESS);
return err;
}
--
2.30.1
The patch titled
Subject: mm, hwpoison: do not lock page again when me_huge_page() successfully recovers
has been added to the -mm tree. Its filename is
mm-hwpoison-do-not-lock-page-again-when-me_huge_page-successfully-recovers.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-hwpoison-do-not-lock-page-agai…
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-hwpoison-do-not-lock-page-agai…
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 and is updated
there every 3-4 working days
------------------------------------------------------
From: Naoya Horiguchi <naoya.horiguchi(a)nec.com>
Subject: mm, hwpoison: do not lock page again when me_huge_page() successfully recovers
Currently me_huge_page() temporary unlocks page to perform some actions
then locks it again later. My testcase (which calls hard-offline on some
tail page in a hugetlb, then accesses the address of the hugetlb range)
showed that page allocation code detects the page lock on buddy page and
printed out "BUG: Bad page state" message. PG_hwpoison does not prevent
it because PG_hwpoison flag is set on any subpage of the hugetlb page but
the 2nd page lock is on the head page.
This patch suggests to drop the 2nd page lock to fix the issue.
Link: https://lkml.kernel.org/r/20210304064437.962442-1-nao.horiguchi@gmail.com
Fixes: commit 78bb920344b8 ("mm: hwpoison: dissolve in-use hugepage in unrecoverable memory error")
Signed-off-by: Naoya Horiguchi <naoya.horiguchi(a)nec.com>
Cc: Michal Hocko <mhocko(a)kernel.org>
Cc: Oscar Salvador <osalvador(a)suse.de>
Cc: Tony Luck <tony.luck(a)intel.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar(a)linux.vnet.ibm.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
mm/memory-failure.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/mm/memory-failure.c~mm-hwpoison-do-not-lock-page-again-when-me_huge_page-successfully-recovers
+++ a/mm/memory-failure.c
@@ -834,7 +834,6 @@ static int me_huge_page(struct page *p,
page_ref_inc(p);
res = MF_RECOVERED;
}
- lock_page(hpage);
}
return res;
@@ -1290,7 +1289,8 @@ static int memory_failure_hugetlb(unsign
res = identify_page_state(pfn, p, page_flags);
out:
- unlock_page(head);
+ if (PageLocked(head))
+ unlock_page(head);
return res;
}
_
Patches currently in -mm which might be from naoya.horiguchi(a)nec.com are
mm-hwpoison-do-not-lock-page-again-when-me_huge_page-successfully-recovers.patch