From a395726cf823fe8f62f1b8c3829010e5652ce98c Mon Sep 17 00:00:00 2001 From: Steve French Date: Wed, 15 May 2024 16:59:01 -0500 Subject: [PATCH] cifs: fix data corruption in read after invalidate When invalidating a file as part of breaking a lease, the folios holding the file data are disposed of, and truncate calls ->invalidate_folio() to get rid of them rather than calling ->release_folio(). This means that the netfs_inode::zero_point value didn't get updated in current upstream code to reflect the point after which we can assume that the server will only return zeroes, and future reads will then return blocks of zeroes if the file got extended for any region beyond the old zero point. Fix this by updating zero_point before invalidating the inode in cifs_revalidate_mapping(). Suggested-by: David Howells Fixes: 3ee1a1fc3981 ("cifs: Cut over to using netfslib") Reviewed-by: David Howells Signed-off-by: Steve French --- fs/smb/client/inode.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/fs/smb/client/inode.c b/fs/smb/client/inode.c index 5d4b0fd3a59e..262576573eb5 100644 --- a/fs/smb/client/inode.c +++ b/fs/smb/client/inode.c @@ -2465,7 +2465,8 @@ int cifs_revalidate_mapping(struct inode *inode) { int rc; - unsigned long *flags = &CIFS_I(inode)->flags; + struct cifsInodeInfo *cifs_inode = CIFS_I(inode); + unsigned long *flags = &cifs_inode->flags; struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb); /* swapfiles are not supposed to be shared */ @@ -2482,6 +2483,7 @@ cifs_revalidate_mapping(struct inode *inode) if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RW_CACHE) goto skip_invalidate; + cifs_inode->netfs.zero_point = cifs_inode->netfs.remote_i_size; rc = filemap_invalidate_inode(inode, true, 0, LLONG_MAX); if (rc) { cifs_dbg(VFS, "%s: invalidate inode %p failed with rc %d\n",