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authorDavid Howells <dhowells@redhat.com>2015-06-18 14:32:31 +0100
committerAl Viro <viro@zeniv.linux.org.uk>2015-06-19 03:19:32 -0400
commit4bacc9c9234c7c8eec44f5ed4e960d9f96fa0f01 (patch)
tree1ecac38332d4e8cf5370627f1214a1d7c5ff7529 /fs/dcache.c
parentf25801ee4680ef1db21e15c112e6e5fe3ffe8da5 (diff)
downloadlinux-4bacc9c9234c7c8eec44f5ed4e960d9f96fa0f01.tar.bz2
overlayfs: Make f_path always point to the overlay and f_inode to the underlay
Make file->f_path always point to the overlay dentry so that the path in /proc/pid/fd is correct and to ensure that label-based LSMs have access to the overlay as well as the underlay (path-based LSMs probably don't need it). Using my union testsuite to set things up, before the patch I see: [root@andromeda union-testsuite]# bash 5</mnt/a/foo107 [root@andromeda union-testsuite]# ls -l /proc/$$/fd/ ... lr-x------. 1 root root 64 Jun 5 14:38 5 -> /a/foo107 [root@andromeda union-testsuite]# stat /mnt/a/foo107 ... Device: 23h/35d Inode: 13381 Links: 1 ... [root@andromeda union-testsuite]# stat -L /proc/$$/fd/5 ... Device: 23h/35d Inode: 13381 Links: 1 ... After the patch: [root@andromeda union-testsuite]# bash 5</mnt/a/foo107 [root@andromeda union-testsuite]# ls -l /proc/$$/fd/ ... lr-x------. 1 root root 64 Jun 5 14:22 5 -> /mnt/a/foo107 [root@andromeda union-testsuite]# stat /mnt/a/foo107 ... Device: 23h/35d Inode: 40346 Links: 1 ... [root@andromeda union-testsuite]# stat -L /proc/$$/fd/5 ... Device: 23h/35d Inode: 40346 Links: 1 ... Note the change in where /proc/$$/fd/5 points to in the ls command. It was pointing to /a/foo107 (which doesn't exist) and now points to /mnt/a/foo107 (which is correct). The inode accessed, however, is the lower layer. The union layer is on device 25h/37d and the upper layer on 24h/36d. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/dcache.c')
-rw-r--r--fs/dcache.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/fs/dcache.c b/fs/dcache.c
index 37b5afdaf698..c4ce35110704 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1673,7 +1673,8 @@ void d_set_d_op(struct dentry *dentry, const struct dentry_operations *op)
DCACHE_OP_COMPARE |
DCACHE_OP_REVALIDATE |
DCACHE_OP_WEAK_REVALIDATE |
- DCACHE_OP_DELETE ));
+ DCACHE_OP_DELETE |
+ DCACHE_OP_SELECT_INODE));
dentry->d_op = op;
if (!op)
return;
@@ -1689,6 +1690,8 @@ void d_set_d_op(struct dentry *dentry, const struct dentry_operations *op)
dentry->d_flags |= DCACHE_OP_DELETE;
if (op->d_prune)
dentry->d_flags |= DCACHE_OP_PRUNE;
+ if (op->d_select_inode)
+ dentry->d_flags |= DCACHE_OP_SELECT_INODE;
}
EXPORT_SYMBOL(d_set_d_op);