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 6204E4AF9F3 for ; Mon, 5 Oct 2026 14:45:07 +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=1791211518; cv=none; b=FiY5hArhxB6Q6sBUzaBhasBvZ9b8dH2soOZLF67oJP7S5AGWm47NlGaWH23N9YqxN1ILlbo8sgAn2H73/Q4RvGDLW4PmukHkP5GKTSzZxeZqSh239B7+gDQyD8km0srOXJn3MnMs/jWy5emzSMVUUilhWNYyagrIO6U7evmXZik= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791211518; c=relaxed/simple; bh=TgyZrqt36OuHEVUoQ1BGffj2dKoBChjZlHINMDbxWKE=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=fER1q5pWqKVW8bCgLYl4+prGfStxHtQlrWA5i5rATV03ukHc4H9UotPPKicThDIJM+KEnjzNQcq3/u08ICH8jrQumoUQR2smn44E+Q0uOb1UFY8bVVJF4M5oUuXGNYrv1PsmdpDShcM+AjqwdQST9j1DtajiNTN4uQNtyBDWm1I= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=CNf8bG49; 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="CNf8bG49" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E906B1F000FF; Mon, 5 Oct 2026 14:45:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1791211505; bh=ypXGqnPvIuL5u7xr1Nrtvp7iMEbNmG2OC6lP2JNmymM=; h=Subject:To:Cc:From:Date; b=CNf8bG49Wx0HHlW2nn6VLQ4jktmjwFK7kyjtqG8ZA/2b5n65c+DitJEIO/RXdtrHx v6yUA6EZSnIdhatoVAs1uBL81C5k+Y2gJwK+CM4hR7hy9K97r8TuiQ3Ia2nN/35M3u cerJlgNcvi0wctbAzvalI9seWpKFMZzRn5qqLAOg= Subject: FAILED: patch "[PATCH] smb: client: clear post-EOF pagecache when extending a file" failed to apply to 7.2-stable tree To: pc@manguebit.org,bharathsm@microsoft.com,brauner@kernel.org,dhowells@redhat.com,linkinjeon@kernel.org,ronniesahlberg@gmail.com,sprasad@microsoft.com,tom@talpey.com,willy@infradead.org Cc: From: Date: Mon, 05 Oct 2026 16:45:02 +0200 Message-ID: <2026100502-cognitive-zipping-a488@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 7.2-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 . 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-7.2.y git checkout FETCH_HEAD git cherry-pick -x 35024595f641e790e24609f3f046e1667e3b280a # git commit -s git send-email --to '' --in-reply-to '2026100502-cognitive-zipping-a488@gregkh' --subject-prefix 'PATCH 7.2.y' 'HEAD^..' Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 35024595f641e790e24609f3f046e1667e3b280a Mon Sep 17 00:00:00 2001 From: Paulo Alcantara Date: Sun, 20 Sep 2026 15:05:44 -0300 Subject: [PATCH] smb: client: clear post-EOF pagecache when extending a file via truncate cifs_setsize() relied on pagecache_isize_extended() to zero the tail of the folio straddling the old EOF, but that helper is a no-op on CIFS (i_blkbits is 14), so data dirtied past EOF through an mmap survived and became visible once the file was extended. Use netfs_clear_stale_post_isize() instead, called after i_size is updated since cifs_setsize() callers hold i_rwsem exclusively for the whole resize. truncate_pagecache() is then called as in truncate_setsize(): a no-op on extend, and it drops the pagecache beyond the new EOF on shrink. Also thread old_size as an explicit parameter through cifs_setsize() and cifs_resize_file_locked(), captured by each caller before its own resize RPC. This closes a race where a concurrent stat() could adopt the RPC's already-updated server size via is_size_safe_to_change() before cifs_setsize() reads old_size itself. Closes: https://sashiko.dev/#/patchset/20260921230755.1133425-1-pc%40manguebit.org Fixes: c510edb9734a ("cifs: call pagecache_isize_extended() in cifs_setsize() when extending") 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 diff --git a/fs/smb/client/cifsfs.h b/fs/smb/client/cifsfs.h index 0c85daa8386e..e3d820c9778b 100644 --- a/fs/smb/client/cifsfs.h +++ b/fs/smb/client/cifsfs.h @@ -146,8 +146,9 @@ ssize_t cifs_file_copychunk_range(unsigned int xid, struct file *src_file, unsigned int flags); long cifs_ioctl(struct file *filep, unsigned int command, unsigned long arg); -void cifs_setsize(struct inode *inode, loff_t offset); -void cifs_resize_file_locked(struct inode *inode, loff_t offset); +void cifs_setsize(struct inode *inode, loff_t old_size, loff_t offset); +void cifs_resize_file_locked(struct inode *inode, loff_t old_size, + loff_t offset); struct fs_context; struct smb3_fs_context; diff --git a/fs/smb/client/file.c b/fs/smb/client/file.c index 0d428517f454..4bcb87610897 100644 --- a/fs/smb/client/file.c +++ b/fs/smb/client/file.c @@ -1017,6 +1017,7 @@ static int cifs_do_truncate(const unsigned int xid, struct dentry *dentry) if (!rc) { if (cfile) { struct netfs_inode *ictx = netfs_inode(inode); + loff_t old_size = i_size_read(inode); tcon = tlink_tcon(cfile->tlink); server = tcon->ses->server; @@ -1025,7 +1026,7 @@ static int cifs_do_truncate(const unsigned int xid, struct dentry *dentry) cfile, 0, false); if (!rc) { netfs_resize_file(&cinode->netfs, 0, true); - cifs_setsize(inode, 0); + cifs_setsize(inode, old_size, 0); cifs_invalidate_cache(inode, 0); } netfs_wb_end(ictx); diff --git a/fs/smb/client/inode.c b/fs/smb/client/inode.c index 1fe0ef0a95db..5062474991cf 100644 --- a/fs/smb/client/inode.c +++ b/fs/smb/client/inode.c @@ -3053,15 +3053,12 @@ int cifs_fiemap(struct inode *inode, struct fiemap_extent_info *fei, u64 start, return -EOPNOTSUPP; } -void cifs_setsize(struct inode *inode, loff_t offset) +void cifs_setsize(struct inode *inode, loff_t old_size, loff_t offset) { - loff_t old_size; u64 blocks = CIFS_INO_BLOCKS(offset); spin_lock(&inode->i_lock); - old_size = i_size_read(inode); i_size_write(inode, offset); - /* * Extending EOF does not allocate the intervening range. Only clamp * i_blocks on shrink; allocation growth comes from writes or from the @@ -3071,20 +3068,28 @@ void cifs_setsize(struct inode *inode, loff_t offset) inode->i_blocks = blocks; spin_unlock(&inode->i_lock); inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode)); + + /* + * Zero the tail of the folio straddling the old EOF so data dirtied + * past EOF through an mmap isn't exposed. truncate_pagecache() then + * drops any pagecache beyond the new EOF, as in truncate_setsize(). + */ if (offset > old_size) - pagecache_isize_extended(inode, old_size, offset); + netfs_clear_stale_post_isize(inode, old_size, offset); + truncate_pagecache(inode, offset); netfs_wait_for_outstanding_io(inode); } -void cifs_resize_file_locked(struct inode *inode, loff_t offset) +void cifs_resize_file_locked(struct inode *inode, loff_t old_size, + loff_t offset) { struct fscache_cookie *cookie = cifs_inode_cookie(inode); lockdep_assert_held_write(&inode->i_rwsem); netfs_resize_file(netfs_inode(inode), offset, true); - cifs_setsize(inode, offset); + cifs_setsize(inode, old_size, offset); if (!cookie) return; @@ -3101,6 +3106,7 @@ int cifs_file_set_size(const unsigned int xid, struct dentry *dentry, struct inode *inode = d_inode(dentry); struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb); struct cifsInodeInfo *cifsInode = CIFS_I(inode); + loff_t old_size = i_size_read(inode); struct tcon_link *tlink = NULL; struct cifs_tcon *tcon = NULL; struct TCP_Server_Info *server; @@ -3159,7 +3165,7 @@ int cifs_file_set_size(const unsigned int xid, struct dentry *dentry, set_size_out: if (rc == 0) - cifs_resize_file_locked(inode, size); + cifs_resize_file_locked(inode, old_size, size); return rc; } diff --git a/fs/smb/client/smb2ops.c b/fs/smb/client/smb2ops.c index aa142420dae2..1ada1c0a728d 100644 --- a/fs/smb/client/smb2ops.c +++ b/fs/smb/client/smb2ops.c @@ -2287,6 +2287,7 @@ smb2_duplicate_extents(const unsigned int xid, struct duplicate_extents_to_file dup_ext_buf; struct timespec64 ts; struct cifs_tcon *tcon = tlink_tcon(trgtfile->tlink); + loff_t old_size; u64 asize; /* server fileays advertise duplicate extent support with this flag */ @@ -2305,11 +2306,12 @@ smb2_duplicate_extents(const unsigned int xid, trgtfile->fid.volatile_fid, tcon->tid, tcon->ses->Suid, src_off, dest_off, len); inode = d_inode(trgtfile->dentry); - if (i_size_read(inode) < dest_off + len) { + old_size = i_size_read(inode); + if (old_size < dest_off + len) { rc = smb2_set_file_size(xid, tcon, trgtfile, dest_off + len, false); if (rc) goto duplicate_extents_out; - cifs_resize_file_locked(inode, dest_off + len); + cifs_resize_file_locked(inode, old_size, dest_off + len); } rc = SMB2_ioctl(xid, tcon, trgtfile->fid.persistent_fid, trgtfile->fid.volatile_fid, @@ -3883,7 +3885,7 @@ static long smb3_simple_falloc(struct file *file, struct cifs_tcon *tcon, } new_eof = off + len; - cifs_resize_file_locked(inode, new_eof); + cifs_resize_file_locked(inode, old_eof, new_eof); qrc = SMB2_query_info(xid, tcon, cfile->fid.persistent_fid, @@ -3931,7 +3933,7 @@ static long smb3_simple_falloc(struct file *file, struct cifs_tcon *tcon, if (rc) goto out; - cifs_resize_file_locked(inode, new_eof); + cifs_resize_file_locked(inode, old_eof, new_eof); qrc = SMB2_query_info(xid, tcon, cfile->fid.persistent_fid,