tree b3cf84a271ccb19529d83a544b6024bbb23a7801
parent a4118ee1d80b527c385cadd14db79559efb8a493
author Al Viro <viro@zeniv.linux.org.uk> 1288337442 -0400
committer Al Viro <viro@zeniv.linux.org.uk> 1288340096 -0400

fix open/umount race

nameidata_to_filp() drops nd->path or transfers it to opened
file.  In the former case it's a Bad Idea(tm) to do mnt_drop_write()
on nd->path.mnt, since we might race with umount and vfsmount in
question might be gone already.

Fix: don't drop it, then...  IOW, have nameidata_to_filp() grab nd->path
in case it transfers it to file and do path_drop() in callers.  After
they are through with accessing nd->path...

Reported-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>