From 9b35348318d13f28219d1a08019d36335cff1475 Mon Sep 17 00:00:00 2001 From: Steve French Date: Mon, 24 Feb 2020 17:37:39 -0600 Subject: [PATCH] smb3: fix performance regression with setting mtime commit cf5371ae460eb8e484e4884747af270c86c3c469 upstream. There are cases when we don't want to send the SMB2 flush operation (e.g. when user specifies mount parm "nostrictsync") and it can be a very expensive operation on the server. In most cases in order to set mtime, we simply need to flush (write) the dirtry pages from the client and send the writes to the server not also send a flush protocol operation to the server. Fixes: aa081859b10c ("cifs: flush before set-info if we have writeable handles") CC: Stable Signed-off-by: Steve French Signed-off-by: Greg Kroah-Hartman --- fs/cifs/inode.c | 23 ++++++++++++----------- 1 file changed, 12 insertions(+), 11 deletions(-) diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c index 7c5e983fe385..5e6bc8fa4e46 100644 --- a/fs/cifs/inode.c +++ b/fs/cifs/inode.c @@ -2454,25 +2454,26 @@ cifs_setattr_nounix(struct dentry *direntry, struct iattr *attrs) /* * Attempt to flush data before changing attributes. We need to do - * this for ATTR_SIZE and ATTR_MTIME for sure, and if we change the - * ownership or mode then we may also need to do this. Here, we take - * the safe way out and just do the flush on all setattr requests. If - * the flush returns error, store it to report later and continue. + * this for ATTR_SIZE and ATTR_MTIME. If the flush of the data + * returns error, store it to report later and continue. * * BB: This should be smarter. Why bother flushing pages that * will be truncated anyway? Also, should we error out here if - * the flush returns error? + * the flush returns error? Do we need to check for ATTR_MTIME_SET flag? */ - rc = filemap_write_and_wait(inode->i_mapping); - if (is_interrupt_error(rc)) { - rc = -ERESTARTSYS; - goto cifs_setattr_exit; + if (attrs->ia_valid & (ATTR_MTIME | ATTR_SIZE | ATTR_CTIME)) { + rc = filemap_write_and_wait(inode->i_mapping); + if (is_interrupt_error(rc)) { + rc = -ERESTARTSYS; + goto cifs_setattr_exit; + } + mapping_set_error(inode->i_mapping, rc); } - mapping_set_error(inode->i_mapping, rc); rc = 0; - if (attrs->ia_valid & ATTR_MTIME) { + if ((attrs->ia_valid & ATTR_MTIME) && + !(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)) { rc = cifs_get_writable_file(cifsInode, FIND_WR_ANY, &wfile); if (!rc) { tcon = tlink_tcon(wfile->tlink);