diff options
author | David Howells <dhowells@redhat.com> | 2012-06-25 07:55:28 -0400 |
---|---|---|
committer | Al Viro <viro@zeniv.linux.org.uk> | 2012-07-14 08:38:32 -0400 |
commit | f015f1267b23d3530d3f874243fb83cb5f443005 (patch) | |
tree | 14db3794b2716614ee8acfaaad011d6fe7e6db44 /fs | |
parent | be34d1a3bc4b6f357a49acb55ae870c81337e4f0 (diff) |
VFS: Comment mount following code
Add comments describing what the directions "up" and "down" mean and ref count
handling to the VFS mount following family of functions.
Signed-off-by: Valerie Aurora <vaurora@redhat.com> (Original author)
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs')
-rw-r--r-- | fs/namei.c | 10 | ||||
-rw-r--r-- | fs/namespace.c | 16 |
2 files changed, 24 insertions, 2 deletions
diff --git a/fs/namei.c b/fs/namei.c index 0e1b9c3eb36d..c6dcb4c8f86c 100644 --- a/fs/namei.c +++ b/fs/namei.c | |||
@@ -672,6 +672,16 @@ static int follow_up_rcu(struct path *path) | |||
672 | return 1; | 672 | return 1; |
673 | } | 673 | } |
674 | 674 | ||
675 | /* | ||
676 | * follow_up - Find the mountpoint of path's vfsmount | ||
677 | * | ||
678 | * Given a path, find the mountpoint of its source file system. | ||
679 | * Replace @path with the path of the mountpoint in the parent mount. | ||
680 | * Up is towards /. | ||
681 | * | ||
682 | * Return 1 if we went up a level and 0 if we were already at the | ||
683 | * root. | ||
684 | */ | ||
675 | int follow_up(struct path *path) | 685 | int follow_up(struct path *path) |
676 | { | 686 | { |
677 | struct mount *mnt = real_mount(path->mnt); | 687 | struct mount *mnt = real_mount(path->mnt); |
diff --git a/fs/namespace.c b/fs/namespace.c index be1b07a774f1..c53d3381b0d0 100644 --- a/fs/namespace.c +++ b/fs/namespace.c | |||
@@ -515,8 +515,20 @@ struct mount *__lookup_mnt(struct vfsmount *mnt, struct dentry *dentry, | |||
515 | } | 515 | } |
516 | 516 | ||
517 | /* | 517 | /* |
518 | * lookup_mnt increments the ref count before returning | 518 | * lookup_mnt - Return the first child mount mounted at path |
519 | * the vfsmount struct. | 519 | * |
520 | * "First" means first mounted chronologically. If you create the | ||
521 | * following mounts: | ||
522 | * | ||
523 | * mount /dev/sda1 /mnt | ||
524 | * mount /dev/sda2 /mnt | ||
525 | * mount /dev/sda3 /mnt | ||
526 | * | ||
527 | * Then lookup_mnt() on the base /mnt dentry in the root mount will | ||
528 | * return successively the root dentry and vfsmount of /dev/sda1, then | ||
529 | * /dev/sda2, then /dev/sda3, then NULL. | ||
530 | * | ||
531 | * lookup_mnt takes a reference to the found vfsmount. | ||
520 | */ | 532 | */ |
521 | struct vfsmount *lookup_mnt(struct path *path) | 533 | struct vfsmount *lookup_mnt(struct path *path) |
522 | { | 534 | { |