From eb4b2df8f20d4479eceeb9bc51695caaa7bcd229 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Tue, 25 Oct 2011 13:59:48 +0200 Subject: vfs pathname lookup: Add LOOKUP_AUTOMOUNT flag Since we've now turned around and made LOOKUP_FOLLOW *not* force an automount, we want to add the ability to force an automount event on lookup even if we don't happen to have one of the other flags that force it implicitly (LOOKUP_OPEN, LOOKUP_DIRECTORY, LOOKUP_PARENT..) Most cases will never want to use this, since you'd normally want to delay automounting as long as possible, which usually implies LOOKUP_OPEN (when we open a file or directory, we really cannot avoid the automount any more). But Trond argued sufficiently forcefully that at a minimum bind mounting a file and quotactl will want to force the automount lookup. Some other cases (like nfs_follow_remote_path()) could use it too, although LOOKUP_DIRECTORY would work there as well. This commit just adds the flag and logic, no users yet, though. It also doesn't actually touch the LOOKUP_NO_AUTOMOUNT flag that is related, and was made irrelevant by the same change that made us not follow on LOOKUP_FOLLOW. Cc: Trond Myklebust Cc: Ian Kent Cc: Jeff Layton Cc: Miklos Szeredi Cc: David Howells Cc: Al Viro Signed-off-by: Linus Torvalds Signed-off-by: Miklos Szeredi Signed-off-by: Greg Kroah-Hartman --- fs/namei.c | 2 +- include/linux/namei.h | 1 + 2 files changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/namei.c b/fs/namei.c index fc12ad5..49472a1 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -793,7 +793,7 @@ static int follow_automount(struct path *path, unsigned flags, * of the daemon to instantiate them before they can be used. */ if (!(flags & (LOOKUP_CONTINUE | LOOKUP_DIRECTORY | - LOOKUP_OPEN | LOOKUP_CREATE)) && + LOOKUP_OPEN | LOOKUP_CREATE | LOOKUP_AUTOMOUNT)) && path->dentry->d_inode) return -EISDIR; diff --git a/include/linux/namei.h b/include/linux/namei.h index 549b7d2..82ab16b 100644 --- a/include/linux/namei.h +++ b/include/linux/namei.h @@ -49,6 +49,7 @@ enum {LAST_NORM, LAST_ROOT, LAST_DOT, LAST_DOTDOT, LAST_BIND}; #define LOOKUP_FOLLOW 0x0001 #define LOOKUP_DIRECTORY 0x0002 #define LOOKUP_CONTINUE 0x0004 +#define LOOKUP_AUTOMOUNT 0x0008 #define LOOKUP_PARENT 0x0010 #define LOOKUP_REVAL 0x0020 -- cgit v1.1