* [PATCH 6.9 221/222] netfs: Fix netfs_page_mkwrite() to check folio->mapping is valid
[not found] <20240702170243.963426416@linuxfoundation.org>
@ 2024-07-02 17:04 ` Greg Kroah-Hartman
2024-07-02 17:04 ` [PATCH 6.9 222/222] netfs: Fix netfs_page_mkwrite() to flush conflicting data, not wait Greg Kroah-Hartman
1 sibling, 0 replies; 2+ messages in thread
From: Greg Kroah-Hartman @ 2024-07-02 17:04 UTC (permalink / raw)
To: stable
Cc: Greg Kroah-Hartman, patches, David Howells, Jeff Layton,
Matthew Wilcox, netfs, v9fs, linux-afs, linux-cifs, linux-mm,
linux-fsdevel, Christian Brauner, Sasha Levin
6.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: David Howells <dhowells@redhat.com>
[ Upstream commit a81c98bfa40c11f8ea79b5a9b3f5fda73bfbb4d2 ]
Fix netfs_page_mkwrite() to check that folio->mapping is valid once it has
taken the folio lock (as filemap_page_mkwrite() does). Without this,
generic/247 occasionally oopses with something like the following:
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
RIP: 0010:trace_event_raw_event_netfs_folio+0x61/0xc0
...
Call Trace:
<TASK>
? __die_body+0x1a/0x60
? page_fault_oops+0x6e/0xa0
? exc_page_fault+0xc2/0xe0
? asm_exc_page_fault+0x22/0x30
? trace_event_raw_event_netfs_folio+0x61/0xc0
trace_netfs_folio+0x39/0x40
netfs_page_mkwrite+0x14c/0x1d0
do_page_mkwrite+0x50/0x90
do_pte_missing+0x184/0x200
__handle_mm_fault+0x42d/0x500
handle_mm_fault+0x121/0x1f0
do_user_addr_fault+0x23e/0x3c0
exc_page_fault+0xc2/0xe0
asm_exc_page_fault+0x22/0x30
This is due to the invalidate_inode_pages2_range() issued at the end of the
DIO write interfering with the mmap'd writes.
Fixes: 102a7e2c598c ("netfs: Allow buffered shared-writeable mmap through netfs_page_mkwrite()")
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/780211.1719318546@warthog.procyon.org.uk
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: Matthew Wilcox <willy@infradead.org>
cc: Jeff Layton <jlayton@kernel.org>
cc: netfs@lists.linux.dev
cc: v9fs@lists.linux.dev
cc: linux-afs@lists.infradead.org
cc: linux-cifs@vger.kernel.org
cc: linux-mm@kvack.org
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/netfs/buffered_write.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/fs/netfs/buffered_write.c b/fs/netfs/buffered_write.c
index 912ad0a1df021..72e4fa233c526 100644
--- a/fs/netfs/buffered_write.c
+++ b/fs/netfs/buffered_write.c
@@ -507,6 +507,7 @@ vm_fault_t netfs_page_mkwrite(struct vm_fault *vmf, struct netfs_group *netfs_gr
{
struct folio *folio = page_folio(vmf->page);
struct file *file = vmf->vma->vm_file;
+ struct address_space *mapping = file->f_mapping;
struct inode *inode = file_inode(file);
vm_fault_t ret = VM_FAULT_RETRY;
int err;
@@ -520,6 +521,11 @@ vm_fault_t netfs_page_mkwrite(struct vm_fault *vmf, struct netfs_group *netfs_gr
if (folio_lock_killable(folio) < 0)
goto out;
+ if (folio->mapping != mapping) {
+ folio_unlock(folio);
+ ret = VM_FAULT_NOPAGE;
+ goto out;
+ }
/* Can we see a streaming write here? */
if (WARN_ON(!folio_test_uptodate(folio))) {
@@ -529,7 +535,7 @@ vm_fault_t netfs_page_mkwrite(struct vm_fault *vmf, struct netfs_group *netfs_gr
if (netfs_folio_group(folio) != netfs_group) {
folio_unlock(folio);
- err = filemap_fdatawait_range(inode->i_mapping,
+ err = filemap_fdatawait_range(mapping,
folio_pos(folio),
folio_pos(folio) + folio_size(folio));
switch (err) {
--
2.43.0
^ permalink raw reply [flat|nested] 2+ messages in thread* [PATCH 6.9 222/222] netfs: Fix netfs_page_mkwrite() to flush conflicting data, not wait
[not found] <20240702170243.963426416@linuxfoundation.org>
2024-07-02 17:04 ` [PATCH 6.9 221/222] netfs: Fix netfs_page_mkwrite() to check folio->mapping is valid Greg Kroah-Hartman
@ 2024-07-02 17:04 ` Greg Kroah-Hartman
1 sibling, 0 replies; 2+ messages in thread
From: Greg Kroah-Hartman @ 2024-07-02 17:04 UTC (permalink / raw)
To: stable
Cc: Greg Kroah-Hartman, patches, David Howells, Matthew Wilcox,
Jeff Layton, netfs, v9fs, linux-afs, linux-cifs, linux-mm,
linux-fsdevel, Christian Brauner, Sasha Levin
6.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: David Howells <dhowells@redhat.com>
[ Upstream commit 9d66154f73b7c7007c3be1113dfb50b99b791f8f ]
Fix netfs_page_mkwrite() to use filemap_fdatawrite_range(), not
filemap_fdatawait_range() to flush conflicting data.
Fixes: 102a7e2c598c ("netfs: Allow buffered shared-writeable mmap through netfs_page_mkwrite()")
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/614300.1719228243@warthog.procyon.org.uk
cc: Matthew Wilcox <willy@infradead.org>
cc: Jeff Layton <jlayton@kernel.org>
cc: netfs@lists.linux.dev
cc: v9fs@lists.linux.dev
cc: linux-afs@lists.infradead.org
cc: linux-cifs@vger.kernel.org
cc: linux-mm@kvack.org
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/netfs/buffered_write.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/fs/netfs/buffered_write.c b/fs/netfs/buffered_write.c
index 72e4fa233c526..d2ce0849bb53d 100644
--- a/fs/netfs/buffered_write.c
+++ b/fs/netfs/buffered_write.c
@@ -535,9 +535,9 @@ vm_fault_t netfs_page_mkwrite(struct vm_fault *vmf, struct netfs_group *netfs_gr
if (netfs_folio_group(folio) != netfs_group) {
folio_unlock(folio);
- err = filemap_fdatawait_range(mapping,
- folio_pos(folio),
- folio_pos(folio) + folio_size(folio));
+ err = filemap_fdatawrite_range(mapping,
+ folio_pos(folio),
+ folio_pos(folio) + folio_size(folio));
switch (err) {
case 0:
ret = VM_FAULT_RETRY;
--
2.43.0
^ permalink raw reply [flat|nested] 2+ messages in thread