linux/fs, branch v4.6

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2016-05-14T18:59:43Z

Pull vfs fixes from Al Viro: "Overlayfs fixes from Miklos, assorted fixes from me. Stable fodder of varying severity, all sat in -next for a while" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: ovl: ignore permissions on underlying lookup vfs: add lookup_hash() helper vfs: rename: check backing inode being equal vfs: add vfs_select_inode() helper get_rock_ridge_filename(): handle malformed NM entries ecryptfs: fix handling of directory opening atomic_open(): fix the handling of create_error fix the copy vs. map logics in blk_rq_map_user_iov() do_splice_to(): cap the size before passing to ->splice_read()

Merge branch 'for-4.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

2016-05-13T23:26:46Z

Pull cgroup fixes from Tejun Heo: "During v4.6-rc1 cgroup namespace support was merged. There is an issue where it's impossible to tell whether a given cgroup mount point is bind mounted or namespaced. Serge has been working on the issue but it took longer than expected to resolve, so the late pull request. Given that it's a completely new feature and the patches don't touch anything else, the risk seems acceptable. However, if this is too late, an alternative is plugging new cgroup ns creation for v4.6 and retrying for v4.7" * 'for-4.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup: fix compile warning kernfs: kernfs_sop_show_path: don't return 0 after seq_dentry call cgroup, kernfs: make mountinfo show properly scoped path for cgroup namespaces kernfs_path_from_node_locked: don't overwrite nlen

ocfs2: fix posix_acl_create deadlock

2016-05-12T22:52:50Z

Commit 702e5bc68ad2 ("ocfs2: use generic posix ACL infrastructure") refactored code to use posix_acl_create. The problem with this function is that it is not mindful of the cluster wide inode lock making it unsuitable for use with ocfs2 inode creation with ACLs. For example, when used in ocfs2_mknod, this function can cause deadlock as follows. The parent dir inode lock is taken when calling posix_acl_create -> get_acl -> ocfs2_iop_get_acl which takes the inode lock again. This can cause deadlock if there is a blocked remote lock request waiting for the lock to be downconverted. And same deadlock happened in ocfs2_reflink. This fix is to revert back using ocfs2_init_acl. Fixes: 702e5bc68ad2 ("ocfs2: use generic posix ACL infrastructure") Signed-off-by: Tariq Saeed Signed-off-by: Junxiao Bi Cc: Mark Fasheh Cc: Joel Becker Cc: Joseph Qi Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ocfs2: revert using ocfs2_acl_chmod to avoid inode cluster lock hang

2016-05-12T22:52:50Z

Commit 743b5f1434f5 ("ocfs2: take inode lock in ocfs2_iop_set/get_acl()") introduced this issue. ocfs2_setattr called by chmod command holds cluster wide inode lock when calling posix_acl_chmod. This latter function in turn calls ocfs2_iop_get_acl and ocfs2_iop_set_acl. These two are also called directly from vfs layer for getfacl/setfacl commands and therefore acquire the cluster wide inode lock. If a remote conversion request comes after the first inode lock in ocfs2_setattr, OCFS2_LOCK_BLOCKED will be set. And this will cause the second call to inode lock from the ocfs2_iop_get_acl() to block indefinetly. The deleted version of ocfs2_acl_chmod() calls __posix_acl_chmod() which does not call back into the filesystem. Therefore, we restore ocfs2_acl_chmod(), modify it slightly for locking as needed, and use that instead. Fixes: 743b5f1434f5 ("ocfs2: take inode lock in ocfs2_iop_set/get_acl()") Signed-off-by: Tariq Saeed Signed-off-by: Junxiao Bi Cc: Mark Fasheh Cc: Joel Becker Cc: Joseph Qi Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kernfs: kernfs_sop_show_path: don't return 0 after seq_dentry call

2016-05-12T15:03:51Z

Our caller expects 0 on success, not >0. This fixes a bug in the patch cgroup, kernfs: make mountinfo show properly scoped path for cgroup namespaces where /sys does not show up in mountinfo, breaking criu. Thanks for catching this, Andrei. Reported-by: Andrei Vagin Signed-off-by: Serge Hallyn Signed-off-by: Tejun Heo

Merge branch 'ovl-fixes' into for-linus

2016-05-11T04:00:29Z

ovl: ignore permissions on underlying lookup

2016-05-11T03:58:18Z

Generally permission checking is not necessary when overlayfs looks up a dentry on one of the underlying layers, since search permission on base directory was already checked in ovl_permission(). More specifically using lookup_one_len() causes a problem when the lower directory lacks search permission for a specific user while the upper directory does have search permission. Since lookups are cached, this causes inconsistency in behavior: success depends on who did the first lookup. So instead use lookup_hash() which doesn't do the permission check. Reported-by: Ignacy Gawędzki Signed-off-by: Miklos Szeredi

vfs: add lookup_hash() helper

2016-05-11T03:56:28Z

Overlayfs needs lookup without inode_permission() and already has the name hash (in form of dentry->d_name on overlayfs dentry). It also doesn't support filesystems with d_op->d_hash() so basically it only needs the actual hashed lookup from lookup_one_len_unlocked() So add a new helper that does unlocked lookup of a hashed name. Signed-off-by: Miklos Szeredi

vfs: rename: check backing inode being equal

2016-05-11T03:55:43Z

If a file is renamed to a hardlink of itself POSIX specifies that rename(2) should do nothing and return success. This condition is checked in vfs_rename(). However it won't detect hard links on overlayfs where these are given separate inodes on the overlayfs layer. Overlayfs itself detects this condition and returns success without doing anything, but then vfs_rename() will proceed as if this was a successful rename (detach_mounts(), d_move()). The correct thing to do is to detect this condition before even calling into overlayfs. This patch does this by calling vfs_select_inode() to get the underlying inodes. Signed-off-by: Miklos Szeredi Cc: # v4.2+

vfs: add vfs_select_inode() helper

2016-05-11T03:55:01Z

Signed-off-by: Miklos Szeredi Cc: # v4.2+