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I don't think this is necessary, vStorage doesn't do invalidate_file on a directory, if we want to guard against mistake from user space</div>
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it's better to add following check:</div>
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diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c</div>
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index ea158367a1ef..f2c6b9e13052 100644</div>
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--- a/fs/fuse/inode.c</div>
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+++ b/fs/fuse/inode.c</div>
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@@ -667,6 +667,9 @@ int fuse_invalidate_files(struct fuse_dev *fud, u64 nodeid)</div>
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if (!inode)</div>
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return -ENOENT;</div>
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+ if (!S_ISREG(inode.i_mode))</div>
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+ return -EOPNOTSUPP;</div>
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+</div>
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fi = get_fuse_inode(inode);</div>
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<b>From:</b> Konstantin Khorenko <khorenko@virtuozzo.com><br>
<b>Sent:</b> 06 July 2026 20:38<br>
<b>To:</b> Alexey Kuznetsov <kuznet@virtuozzo.com>; Kui Liu <kui.liu@virtuozzo.com><br>
<b>Cc:</b> OpenVZ devel list <devel@openvz.org><br>
<b>Subject:</b> Re: [PATCH vz10 02/24] fuse: don't wake page_waitq for non-regular inodes in the invalidate worker</div>
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<div style="font-size: 11pt;">Guys, please, review the patch.<br>
<br>
--<br>
Best regards,<br>
<br>
Konstantin Khorenko,<br>
Virtuozzo Linux Kernel Team<br>
<br>
On 7/6/26 12:59, Konstantin Khorenko wrote:<br>
> fi->page_waitq lives in an anonymous union in struct fuse_inode that is only valid for regular files; for a directory the same storage holds the readdir cache (fi->rdc, including rdc.lock). fuse_inval_files_work(), handling FUSE_NOTIFY_INVAL_FILES, called
wake_up(&fi->page_waitq) for whatever inode the notification targeted -- including directories such as the mount root. Waking page_waitq on a directory walks readdir-cache fields as a wait-queue list.<br>
><br>
> On a production kernel this stays silent until the directory has been readdir'd (page_waitq.head overlaps rdc.iversion/rdc.lock); once readdir has cached data an INVAL_FILES for that directory walks rdc.iversion as a list pointer -> GPF, with rdc.mtime acting
as the 'lock' -> lockup. On a lockdep kernel (64-byte spinlock_t) page_waitq.head.next overlaps rdc.lock.dep_map.name exactly, so it faults on the first directory INVAL_FILES, dereferencing the "&fi->rdc.lock" rodata string as a wait_queue_entry (GPF at a
non-canonical ASCII address in the fuse_inval_files_work worker).<br>
><br>
> All page_waitq waiters (fuse_release, fuse_wait_on_page_writeback, fuse_set_nowrite) and wakers are regular files, so guard the worker's wake_up() with S_ISREG(). fuse_init_file_inode() already initialises page_waitq for every regular-file inode, so no alloc-time
init is needed.<br>
><br>
> Fixes: 2604b00b9f44 ("fuse: skip waiting for fuse writeback")<br>
> Feature: vStorage<br>
> <a href="https://virtuozzo.atlassian.net/browse/VSTOR-137234" id="OWAa5f69b28-1501-2d0d-9d08-6e1514fdd932" class="OWAAutoLink" data-auth="NotApplicable">
https://virtuozzo.atlassian.net/browse/VSTOR-137234</a><br>
> Signed-off-by: Konstantin Khorenko <khorenko@virtuozzo.com><br>
> ---<br>
> fs/fuse/inode.c | 11 ++++++++++-<br>
> 1 file changed, 10 insertions(+), 1 deletion(-)<br>
><br>
> diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c<br>
> index ea158367a1ef..26c0014ccf0f 100644<br>
> --- a/fs/fuse/inode.c<br>
> +++ b/fs/fuse/inode.c<br>
> @@ -632,7 +632,16 @@ static void fuse_inval_files_work(struct work_struct *w)<br>
> fuse_revoke_readpages(ff);<br>
> spin_unlock(&fi->lock);<br>
> <br>
> - wake_up(&fi->page_waitq); /* readpage[s] can wait on fuse wb */<br>
> + /*<br>
> + * page_waitq lives in a union in struct fuse_inode that is only<br>
> + * valid for regular files; on a directory those bytes are the<br>
> + * readdir cache (fi->rdc, incl. rdc.lock), so waking it up walks<br>
> + * readdir-cache fields as a waitqueue list. All page_waitq<br>
> + * waiters (readpage[s] waiting on fuse writeback) are regular<br>
> + * files, so only wake it for those.<br>
> + */<br>
> + if (S_ISREG(fi->inode.i_mode))<br>
> + wake_up(&fi->page_waitq); /* readpage[s] can wait on fuse wb */<br>
> <br>
> truncate_pagecache_range(&fi->inode, 0, -1);<br>
> fuse_invalidate_attr(&fi->inode);<br>
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