From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 998CA4A35; Tue, 13 Oct 2026 12:46:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791895615; cv=none; b=bkigW/T+/9bR0rF8AwilUoEKNl9r/hIzEwVi1nrYpwDVT6qH7uGQtUtvgqAyzmpd0rnmmD9J5hbj74oRhf5+R4jlPO0YPKDWDRm9x1UfnoDV3ir5emsMJJQoxH2P+UNxYIhOV4s5KX6PLgAF1GCfwuuTDaItUvJVIp5I95boSpI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791895615; c=relaxed/simple; bh=ro3RivbK+WoAoZOnc9U4j+BHfkcS4IALx8j08IwxgK0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=gaYCbyzsg8pdkNHhdcE6k1RIq5BakF1k+0up7SndSf+66+XBfrG1Ayxna5XtNkHrESW62x32kzuUD7QDWh0ce//AkdQStTLahJ3PlpGkjoCKBZs/rCZJnA+j+iATjD6SgCpTLnA7cTkEswuWcNc9yme2mfGxj+rBlZ5waz2Ph/I= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Yvg289WX; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Yvg289WX" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E6B9B1F00893; Tue, 13 Oct 2026 12:46:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1791895614; bh=ff51v1hCzvzN93Klr7Q5Eg6EN3xm7ZIVb0WeDYSneLU=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Yvg289WXt+LH+g1rGjh5qzxTBAtgPsrg3cebB8/3XRZlwtVClo8W+lQSWdgk3a20C dTJUIYL7uXaYYaL7Tk0nKQkLWKJd+oSfSoDI5cTnd50zFOGxtZL2p7VZJ4SNX10IRe k/uThSUCfUBYsVrm61/W7R+6VuPn1iKJ1JUJKxH8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, David Howells , Namjae Jeon , Paulo Alcantara , Christian Brauner , Matthew Wilcox , Ronnie Sahlberg , Shyam Prasad N , Tom Talpey , Bharath SM , Sasha Levin Subject: [PATCH 6.12 335/497] smb: client: only require read lease for size-extending preallocate Date: Tue, 13 Oct 2026 13:38:22 +0200 Message-ID: <20261013112915.856172533@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261013112907.864180619@linuxfoundation.org> References: <20261013112907.864180619@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Paulo Alcantara [ Upstream commit b5d59e7270d078ab28a9c4b4d11dc3eb24671988 ] smb3_simple_falloc() refuses any fallocate that clears FALLOC_FL_KEEP_SIZE with -EOPNOTSUPP whenever the inode is not read caching: /* if file not oplocked can't be sure whether asking to extend size */ if (!CIFS_CACHE_READ(cifsi)) if (!keep_size) { ... return rc; } As with smb3_zero_range(), the read lease is only needed to trust the cached size when deciding whether the request extends the file. When it is not held, the size can instead be fetched from the server, which is authoritative, rather than refusing the request outright: after flushing, query the server's end of file and take the larger of it and the cached size for the interior-vs-extend decision. The larger of the two is used because the server's end of file reflects another client's growth while the cached size reflects this client's own writes that may not have reached the server yet; using the server size alone would wrongly treat an interior request as extending when a range flush left an extending write unwritten. smb3_simple_fallocate_range(), which performs the actual interior emulation, decided whether the range already lies past EOF from its own i_size_read(inode) rather than the old_eof computed above. In the leaseless case, that is exactly the stale, undershooting size this patch works around: a genuinely interior range can read as past EOF by that stale count, which skips the FSCTL_QUERY_ALLOCATED_RANGES check entirely and overwrites already-allocated server data with zeroes instead of only filling the holes. Pass old_eof into smb3_simple_fallocate_range() and use it for that comparison instead of re-deriving a second, inconsistent one. Rejecting interior requests is observed as generic/363 randomly failing against Windows Server with do_preallocate: fallocate: Operation not supported fsx issues an interior, non-KEEP_SIZE preallocate while the inode is transiently not read caching: the server had just downgraded the file's lease from RWH to RH after breaking the write caching, and the ensuing handle reopen/revalidation left CIFS_CACHE_READ momentarily clear. The range sat within the server's end of file, so no extend was needed, yet it was refused and fsx aborted. This keeps the emulation correct even when a genuine lease break from another client leaves the inode without read caching -- the case the -EOPNOTSUPP guard turned into a hard failure. The extra flush and round trip only happen when both keep_size is false and no read lease is held; every other case is unchanged. Fixes: 9ccf3216238c ("Add support for original fallocate") Reviewed-by: David Howells Reviewed-by: Namjae Jeon Signed-off-by: Paulo Alcantara Cc: Christian Brauner Cc: Matthew Wilcox Cc: Ronnie Sahlberg Cc: Shyam Prasad N Cc: Tom Talpey Cc: Bharath SM Cc: stable@vger.kernel.org [ sashal: Replaced unavailable query_server_eof() with an equivalent SMB2_query_info() call. ] Signed-off-by: Sasha Levin --- fs/smb/client/smb2ops.c | 33 ++++++++++++++++++++++++++------- 1 file changed, 26 insertions(+), 7 deletions(-) diff --git a/fs/smb/client/smb2ops.c b/fs/smb/client/smb2ops.c index 417d0873dae32..55484d38ffe98 100644 --- a/fs/smb/client/smb2ops.c +++ b/fs/smb/client/smb2ops.c @@ -3779,28 +3779,47 @@ static long smb3_simple_falloc(struct file *file, struct cifs_tcon *tcon, struct cifsFileInfo *cfile = file->private_data; long rc = -EOPNOTSUPP; unsigned int xid; - loff_t new_eof; + loff_t old_eof, new_eof; xid = get_xid(); inode = d_inode(cfile->dentry); cifsi = CIFS_I(inode); + old_eof = i_size_read(inode); trace_smb3_falloc_enter(xid, cfile->fid.persistent_fid, tcon->tid, tcon->ses->Suid, off, len); - /* if file not oplocked can't be sure whether asking to extend size */ - if (!CIFS_CACHE_READ(cifsi)) - if (keep_size == false) { + + if (!keep_size && !CIFS_CACHE_READ(cifsi)) { + struct smb2_file_all_info file_inf = {}; + unsigned long long server_eof; + + rc = filemap_write_and_wait(inode->i_mapping); + if (rc) { + trace_smb3_falloc_err(xid, cfile->fid.persistent_fid, + tcon->tid, tcon->ses->Suid, off, len, rc); + free_xid(xid); + return rc; + } + netfs_wait_for_outstanding_io(inode); + + rc = SMB2_query_info(xid, tcon, cfile->fid.persistent_fid, + cfile->fid.volatile_fid, &file_inf); + if (rc) { trace_smb3_falloc_err(xid, cfile->fid.persistent_fid, tcon->tid, tcon->ses->Suid, off, len, rc); free_xid(xid); return rc; } + server_eof = le64_to_cpu(file_inf.EndOfFile); + /* Only use the larger EOF to decide whether we're extending. */ + old_eof = max_t(loff_t, old_eof, server_eof); + } /* * Extending the file */ - if ((keep_size == false) && i_size_read(inode) < off + len) { + if (!keep_size && old_eof < off + len) { rc = inode_newsize_ok(inode, off + len); if (rc) goto out; @@ -3848,7 +3867,7 @@ static long smb3_simple_falloc(struct file *file, struct cifs_tcon *tcon, } } - if ((keep_size == true) || (i_size_read(inode) >= off + len)) { + if (keep_size || old_eof >= off + len) { /* * At this point, we are trying to fallocate an internal * regions of a sparse file. Since smb2 does not have a @@ -3877,7 +3896,7 @@ static long smb3_simple_falloc(struct file *file, struct cifs_tcon *tcon, * ie potentially making a few extra pages at the beginning * or end of the file non-sparse via set_sparse is harmless. */ - if ((off > 8192) || (off + len + 8192 < i_size_read(inode))) { + if (off > 8192 || off + len + 8192 < old_eof) { rc = -EOPNOTSUPP; goto out; } -- 2.53.0