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Commit 2846d386 authored by Jeff Layton's avatar Jeff Layton Committed by Steve French
Browse files

cifs: have find_writeable_file prefer filehandles opened by same task 



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: default avatarJeff Layton <jlayton@redhat.com>
Signed-off-by: default avatarSteve French <sfrench@us.ibm.com>
parent 232087cb

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 @@ struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode) 
			   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;

}