cifs: have find_writeable_file prefer filehandles opened by same task (2846d386) · Commits · 戴 / test

When the CIFS client goes to write out pages, it needs to pick a filehandle to write to. find_writeable_file however just picks the first filehandle that it finds. This can cause problems when a lock is issued against a particular filehandle and we pick a different filehandle to write to. This patch tries to avert this situation by having find_writable_file prefer filehandles that have a pid that matches the current task. This seems to fix lock test 11 from the connectathon test suite when run against a windows server. Signed-off-by:

Jeff Layton <jlayton@redhat.com> Signed-off-by:

Steve French <sfrench@us.ibm.com>

fs/cifs/file.c

+9 −1

Original line number	Diff line number	Diff line
		@@ -1065,6 +1065,7 @@ struct cifsFileInfo find_readable_file(struct cifsInodeInfo cifs_inode)
		struct cifsFileInfo find_writable_file(struct cifsInodeInfo cifs_inode)
		{
		struct cifsFileInfo *open_file;
		bool any_available = false;
		int rc;

		/* Having a null inode here (because mapping->host was set to zero by
		@@ -1080,8 +1081,10 @@ struct cifsFileInfo find_writable_file(struct cifsInodeInfo cifs_inode)
		read_lock(&GlobalSMBSeslock);
		refind_writable:
		list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
		if (open_file->closePend)
		if (open_file->closePend \|\|
		(!any_available && open_file->pid != current->tgid))
		continue;

		if (open_file->pfile &&
		((open_file->pfile->f_flags & O_RDWR) \|\|
		(open_file->pfile->f_flags & O_WRONLY))) {
		@@ -1131,6 +1134,11 @@ refind_writable:
		of the loop here. */
		}
		}
		/* couldn't find useable FH with same pid, try any available */
		if (!any_available) {
		any_available = true;
		goto refind_writable;
		}
		read_unlock(&GlobalSMBSeslock);
		return NULL;
		}

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