cifs: have find_readable/writable_file filter by fsuid
When we implement multiuser mounts, we'll need to filter filehandles
by fsuid. Add a flag for multiuser mounts and code to filter by
fsuid when it's set.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 24332d4..80856f1 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -1168,9 +1168,15 @@
}
#ifdef CONFIG_CIFS_EXPERIMENTAL
-struct cifsFileInfo *find_readable_file(struct cifsInodeInfo *cifs_inode)
+struct cifsFileInfo *find_readable_file(struct cifsInodeInfo *cifs_inode,
+ bool fsuid_only)
{
struct cifsFileInfo *open_file = NULL;
+ struct cifs_sb_info *cifs_sb = CIFS_SB(cifs_inode->vfs_inode.i_sb);
+
+ /* only filter by fsuid on multiuser mounts */
+ if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
+ fsuid_only = false;
read_lock(&GlobalSMBSeslock);
/* we could simply get the first_list_entry since write-only entries
@@ -1179,6 +1185,8 @@
list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
if (open_file->closePend)
continue;
+ if (fsuid_only && open_file->uid != current_fsuid())
+ continue;
if (open_file->pfile && ((open_file->pfile->f_flags & O_RDWR) ||
(open_file->pfile->f_flags & O_RDONLY))) {
if (!open_file->invalidHandle) {
@@ -1198,9 +1206,11 @@
}
#endif
-struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode)
+struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode,
+ bool fsuid_only)
{
struct cifsFileInfo *open_file;
+ struct cifs_sb_info *cifs_sb = CIFS_SB(cifs_inode->vfs_inode.i_sb);
bool any_available = false;
int rc;
@@ -1214,13 +1224,19 @@
return NULL;
}
+ /* only filter by fsuid on multiuser mounts */
+ if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
+ fsuid_only = false;
+
read_lock(&GlobalSMBSeslock);
refind_writable:
list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
- if (open_file->closePend ||
- (!any_available && open_file->pid != current->tgid))
+ if (open_file->closePend)
continue;
-
+ if (!any_available && open_file->pid != current->tgid)
+ continue;
+ if (fsuid_only && open_file->uid != current_fsuid())
+ continue;
if (open_file->pfile &&
((open_file->pfile->f_flags & O_RDWR) ||
(open_file->pfile->f_flags & O_WRONLY))) {
@@ -1315,7 +1331,7 @@
if (mapping->host->i_size - offset < (loff_t)to)
to = (unsigned)(mapping->host->i_size - offset);
- open_file = find_writable_file(CIFS_I(mapping->host));
+ open_file = find_writable_file(CIFS_I(mapping->host), false);
if (open_file) {
bytes_written = cifs_write(open_file->pfile, write_data,
to-from, &offset);
@@ -1388,7 +1404,7 @@
* but it'll at least handle the return. Maybe it should be
* a BUG() instead?
*/
- open_file = find_writable_file(CIFS_I(mapping->host));
+ open_file = find_writable_file(CIFS_I(mapping->host), false);
if (!open_file) {
kfree(iov);
return generic_writepages(mapping, wbc);
@@ -1505,7 +1521,8 @@
break;
}
if (n_iov) {
- open_file = find_writable_file(CIFS_I(mapping->host));
+ open_file = find_writable_file(CIFS_I(mapping->host),
+ false);
if (!open_file) {
cERROR(1, "No writable handles for inode");
rc = -EBADF;