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2017-11-02ovl: do not cleanup unsupported index entriesAmir Goldstein2-10/+8
commit fa0096e3bad69ed6f34843fd7ae1c45ca987012a upstream. With index=on, ovl_indexdir_cleanup() tries to cleanup invalid index entries (e.g. bad index name). This behavior could result in cleaning of entries created by newer kernels and is therefore undesirable. Instead, abort mount if such entries are encountered. We still cleanup 'stale' entries and 'orphan' entries, both those cases can be a result of offline changes to lower and upper dirs. When encoutering an index entry of type directory or whiteout, kernel was supposed to fallback to read-only mount, but the fill_super() operation returns EROFS in this case instead of returning success with read-only mount flag, so mount fails when encoutering directory or whiteout index entries. Bless this behavior by returning -EINVAL on directory and whiteout index entries as we do for all unsupported index entries. Fixes: 61b674710cd9 ("ovl: do not cleanup directory and whiteout index..") Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02ovl: handle ENOENT on index lookupAmir Goldstein1-0/+4
commit 7937a56fdf0b064c2ffa33025210f725a4ebc822 upstream. Treat ENOENT from index entry lookup the same way as treating a returned negative dentry. Apparently, either could be returned if file is not found, depending on the underlying file system. Fixes: 359f392ca53e ("ovl: lookup index entry for copy up origin") Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02ovl: fix EIO from lookup of non-indexed upperAmir Goldstein3-17/+26
commit 6eaf011144af10cad34c0d46f82e50d382c8e926 upstream. Commit fbaf94ee3cd5 ("ovl: don't set origin on broken lower hardlink") attempt to avoid the condition of non-indexed upper inode with lower hardlink as origin. If this condition is found, lookup returns EIO. The protection of commit mentioned above does not cover the case of lower that is not a hardlink when it is copied up (with either index=off/on) and then lower is hardlinked while overlay is offline. Changes to lower layer while overlayfs is offline should not result in unexpected behavior, so a permanent EIO error after creating a link in lower layer should not be considered as correct behavior. This fix replaces EIO error with success in cases where upper has origin but no index is found, or index is found that does not match upper inode. In those cases, lookup will not fail and the returned overlay inode will be hashed by upper inode instead of by lower origin inode. Fixes: 359f392ca53e ("ovl: lookup index entry for copy up origin") Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02ovl: add NULL check in ovl_alloc_inodeHirofumi Nakagawa1-0/+3
commit b3885bd6edb41b91a0e3976469f72ae31bfb8d95 upstream. This was detected by fault injection test Signed-off-by: Hirofumi Nakagawa <nklabs@gmail.com> Fixes: 13cf199d0088 ("ovl: allocate an ovl_inode struct") Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-12ovl: fix regression caused by exclusive upper/work dir protectionAmir Goldstein2-8/+22
commit 85fdee1eef1a9e48ad5716916677e0c5fbc781e3 upstream. Enforcing exclusive ownership on upper/work dirs caused a docker regression: https://github.com/moby/moby/issues/34672. Euan spotted the regression and pointed to the offending commit. Vivek has brought the regression to my attention and provided this reproducer: Terminal 1: mount -t overlay -o workdir=work,lowerdir=lower,upperdir=upper none merged/ Terminal 2: unshare -m Terminal 1: umount merged mount -t overlay -o workdir=work,lowerdir=lower,upperdir=upper none merged/ mount: /root/overlay-testing/merged: none already mounted or mount point busy To fix the regression, I replaced the error with an alarming warning. With index feature enabled, mount does fail, but logs a suggestion to override exclusive dir protection by disabling index. Note that index=off mount does take the inuse locks, so a concurrent index=off will issue the warning and a concurrent index=on mount will fail. Documentation was updated to reflect this change. Fixes: 2cac0c00a6cd ("ovl: get exclusive ownership on upper/work dirs") Reported-by: Euan Kemp <euank@euank.com> Reported-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-12ovl: fix missing unlock_rename() in ovl_do_copy_up()Amir Goldstein4-24/+22
commit 5820dc0888d302ac05f8b91ffdf7e4e53b4fbf53 upstream. Use the ovl_lock_rename_workdir() helper which requires unlock_rename() only on lock success. Fixes: ("fd210b7d67ee ovl: move copy up lock out") Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-12ovl: fix dentry leak in ovl_indexdir_cleanup()Amir Goldstein1-2/+4
commit dc7ab6773e8171e07f16fd0df0c5eea28c899503 upstream. index dentry was not released when breaking out of the loop due to index verification error. Fixes: 415543d5c64f ("ovl: cleanup bad and stale index entries on mount") Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-12ovl: fix dput() of ERR_PTR in ovl_cleanup_index()Amir Goldstein1-1/+4
commit 9f4ec904dbd4eb1a2db10d5e7dc16eae386fe64d upstream. Fixes: caf70cb2ba5d ("ovl: cleanup orphan index entries") Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-12ovl: fix error value printed in ovl_lookup_index()Amir Goldstein1-0/+1
commit e0082a0f04c432cb6d7128ef60d8e425e45ce025 upstream. Fixes: 359f392ca53e ("ovl: lookup index entry for copy up origin") Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-20ovl: fix false positive ESTALE on lookupAmir Goldstein1-4/+7
commit 939ae4efd51c627da270af74ef069db5124cb5b0 upstream. Commit b9ac5c274b8c ("ovl: hash overlay non-dir inodes by copy up origin") verifies that the origin lower inode stored in the overlayfs inode matched the inode of a copy up origin dentry found by lookup. There is a false positive result in that check when lower fs does not support file handles and copy up origin cannot be followed by file handle at lookup time. The false negative happens when finding an overlay inode in cache on a copied up overlay dentry lookup. The overlay inode still 'remembers' the copy up origin inode, but the copy up origin dentry is not available for verification. Relax the check in case copy up origin dentry is not available. Fixes: b9ac5c274b8c ("ovl: hash overlay non-dir inodes by copy up...") Reported-by: Jordi Pujol <jordipujolp@gmail.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-20ovl: check for bad and whiteout index on lookupAmir Goldstein1-5/+17
Index should always be of the same file type as origin, except for the case of a whiteout index. A whiteout index should only exist if all lower aliases have been unlinked, which means that finding a lower origin on lookup whose index is a whiteout should be treated as a lookup error. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-20ovl: do not cleanup directory and whiteout index entriesAmir Goldstein2-5/+19
Directory index entries are going to be used for looking up redirected upper dirs by lower dir fh when decoding an overlay file handle of a merge dir. Whiteout index entries are going to be used as an indication that an exported overlay file handle should be treated as stale (i.e. after unlink of the overlay inode). We don't know the verification rules for directory and whiteout index entries, because they have not been implemented yet, so fail to mount overlay rw if those entries are found to avoid corrupting an index that was created by a newer kernel. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-20ovl: fix xattr get and set with selinuxMiklos Szeredi4-23/+31
inode_doinit_with_dentry() in SELinux wants to read the upper inode's xattr to get security label, and ovl_xattr_get() calls ovl_dentry_real(), which depends on dentry->d_inode, but d_inode is null and not initialized yet at this point resulting in an Oops. Fix by getting the upperdentry info from the inode directly in this case. Reported-by: Eryu Guan <eguan@redhat.com> Fixes: 09d8b586731b ("ovl: move __upperdentry to ovl_inode") Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-13ovl: remove unneeded check for IS_ERR()Amir Goldstein1-4/+0
ovl_workdir_create() returns a valid index dentry or NULL. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-13ovl: fix origin verification of index dirAmir Goldstein1-1/+2
Commit 54fb347e836f ("ovl: verify index dir matches upper dir") introduced a new ovl_fh flag OVL_FH_FLAG_PATH_UPPER to indicate an upper file handle, but forgot to add the flag to the mask of valid flags, so index dir origin verification always discards existing origin and stores a new one. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-13ovl: mark parent impure on ovl_link()Amir Goldstein1-4/+18
When linking a file with copy up origin into a new parent, mark the new parent dir "impure". Fixes: ee1d6d37b6b8 ("ovl: mark upper dir with type origin entries "impure"") Cc: <stable@vger.kernel.org> # v4.12 Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-13ovl: fix random return value on mountAmir Goldstein1-0/+1
On failure to prepare_creds(), mount fails with a random return value, as err was last set to an integer cast of a valid lower mnt pointer or set to 0 if inodes index feature is enabled. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Fixes: 3fe6e52f0626 ("ovl: override creds with the ones from ...") Cc: <stable@vger.kernel.org> # v4.7 Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-04ovl: mark parent impure and restore timestamp on ovl_link_up()Amir Goldstein1-24/+33
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2017-07-04ovl: cleanup orphan index entriesAmir Goldstein5-5/+77
index entry should live only as long as there are upper or lower hardlinks. Cleanup orphan index entries on mount and when dropping the last overlay inode nlink. When about to cleanup or link up to orphan index and the index inode nlink > 1, admit that something went wrong and adjust overlay nlink to index inode nlink - 1 to prevent it from dropping below zero. This could happen when adding lower hardlinks underneath a mounted overlay and then trying to unlink them. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-04ovl: persistent overlay inode nlink for indexed inodesAmir Goldstein5-3/+204
With inodes index enabled, an overlay inode nlink counts the union of upper and non-covered lower hardlinks. During the lifetime of a non-pure upper inode, the following nlink modifying operations can happen: 1. Lower hardlink copy up 2. Upper hardlink created, unlinked or renamed over 3. Lower hardlink whiteout or renamed over For the first, copy up case, the union nlink does not change, whether the operation succeeds or fails, but the upper inode nlink may change. Therefore, before copy up, we store the union nlink value relative to the lower inode nlink in the index inode xattr trusted.overlay.nlink. For the second, upper hardlink case, the union nlink should be incremented or decremented IFF the operation succeeds, aligned with nlink change of the upper inode. Therefore, before link/unlink/rename, we store the union nlink value relative to the upper inode nlink in the index inode. For the last, lower cover up case, we simplify things by preceding the whiteout or cover up with copy up. This makes sure that there is an index upper inode where the nlink xattr can be stored before the copied up upper entry is unlink. Return the overlay inode nlinks for indexed upper inodes on stat(2). Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-04ovl: implement index dir copy upAmir Goldstein3-37/+103
Implement a copy up method for non-dir objects using index dir to prevent breaking lower hardlinks on copy up. This method requires that the inodes index dir feature was enabled and that all underlying fs support file handle encoding/decoding. On the first lower hardlink copy up, upper file is created in index dir, named after the hex representation of the lower origin inode file handle. On the second lower hardlink copy up, upper file is found in index dir, by the same lower handle key. On either case, the upper indexed inode is then linked to the copy up upper path. The index entry remains linked for future lower hardlink copy up and for lower to upper inode map, that is needed for exporting overlayfs to NFS. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-04ovl: move copy up lock outMiklos Szeredi1-25/+13
Move ovl_copy_up_start()/ovl_copy_up_end() out so that it's used for both tempfile and workdir copy ups. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-04ovl: rearrange copy upMiklos Szeredi1-36/+50
Split up and rearrange copy up functions to make them better readable. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-04ovl: add flag for upper in ovl_entryMiklos Szeredi7-2/+31
For rename, we need to ensure that an upper alias exists for hard links before attempting the operation. Introduce a flag in ovl_entry to track the state of the upper alias. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-04ovl: use struct copy_up_ctx as function argumentMiklos Szeredi1-82/+78
This cleans up functions with too many arguments. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-04ovl: base tmpfile in workdir tooMiklos Szeredi1-5/+3
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-04ovl: factor out ovl_copy_up_inode() helperAmir Goldstein1-17/+29
Factor out helper for copying lower inode data and metadata to temp upper inode, that is common to copy up using O_TMPFILE and workdir. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-04ovl: extract helper to get temp file in copy upMiklos Szeredi1-18/+41
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-04ovl: defer upper dir lock to tempfile linkAmir Goldstein2-30/+38
On copy up of regular file using an O_TMPFILE, lock upper dir only before linking the tempfile in place. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-04ovl: hash overlay non-dir inodes by copy up originMiklos Szeredi3-9/+44
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-04ovl: cleanup bad and stale index entries on mountAmir Goldstein5-10/+130
Bad index entries are entries whose name does not match the origin file handle stored in trusted.overlay.origin xattr. Bad index entries could be a result of a system power off in the middle of copy up. Stale index entries are entries whose origin file handle is stale. Stale index entries could be a result of copying layers or removing lower entries while the overlay is not mounted. The case of copying layers should be detected earlier by the verification of upper root dir origin and index dir origin. Both bad and stale index entries are detected and removed on mount. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-04ovl: lookup index entry for copy up originAmir Goldstein3-2/+116
When inodes index feature is enabled, lookup in indexdir for the index entry of lower real inode or copy up origin inode. The index entry name is the hex representation of the lower inode file handle. If the index dentry in negative, then either no lower aliases have been copied up yet, or aliases have been copied up in older kernels and are not indexed. If the index dentry for a copy up origin inode is positive, but points to an inode different than the upper inode, then either the upper inode has been copied up and not indexed or it was indexed, but since then index dir was cleared. Either way, that index cannot be used to indentify the overlay inode. If a positive dentry that matches the upper inode was found, then it is safe to use the copy up origin st_ino for upper hardlinks, because all indexed upper hardlinks are represented by the same overlay inode as the copy up origin. Set the INDEX type flag on an indexed upper dentry. A non-upper dentry may also have a positive index from copy up of another lower hardlink. This situation will be handled by following patches. Index lookup is going to be used to prevent breaking hardlinks on copy up. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-04ovl: verify index dir matches upper dirAmir Goldstein4-8/+27
An index dir contains persistent hardlinks to files in upper dir. Therefore, we must never mount an existing index dir with a differnt upper dir. Store the upper root dir file handle in index dir inode when index dir is created and verify the file handle before using an existing index dir on mount. Add an 'is_upper' flag to the overlay file handle encoding and set it when encoding the upper root file handle. This is not critical for index dir verification, but it is good practice towards a standard overlayfs file handle format for NFS export. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-04ovl: verify upper root dir matches lower root dirAmir Goldstein4-15/+101
When inodes index feature is enabled, verify that the file handle stored in upper root dir matches the lower root dir or fail to mount. If upper root dir has no stored file handle, encode and store the lower root dir file handle in overlay.origin xattr. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-04ovl: introduce the inodes index dir featureAmir Goldstein6-7/+108
Create the index dir on mount. The index dir will contain hardlinks to upper inodes, named after the hex representation of their origin lower inodes. The index dir is going to be used to prevent breaking lower hardlinks on copy up and to implement overlayfs NFS export. Because the feature is not fully backward compat, enabling the feature is opt-in by config/module/mount option. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-04ovl: generalize ovl_create_workdir()Amir Goldstein1-16/+25
Pass in the subdir name to create and specify if subdir is persistent or if it should be cleaned up on every mount. Move fallback to readonly mount on failure to create dir and print of error message into the helper. This function is going to be used for creating the persistent 'index' dir under workbasedir. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-04ovl: relax same fs constrain for ovl_check_origin()Amir Goldstein1-18/+24
For the case of all layers not on the same fs, try to decode the copy up origin file handle on any of the lower layers. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-04ovl: get exclusive ownership on upper/work dirsAmir Goldstein2-3/+29
Bad things can happen if several concurrent overlay mounts try to use the same upperdir/workdir path. Try to get the 'inuse' advisory lock on upperdir and workdir. Fail mount if another overlay mount instance or another user holds the 'inuse' lock on these directories. Note that this provides no protection for concurrent overlay mount that use overlapping (i.e. descendant) upper/work dirs. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-04vfs: introduce inode 'inuse' lockAmir Goldstein2-0/+33
Added an i_state flag I_INUSE and helpers to set/clear/test the bit. The 'inuse' lock is an 'advisory' inode lock, that can be used to extend exclusive create protection beyond parent->i_mutex lock among cooperating users. This is going to be used by overlayfs to get exclusive ownership on upper and work dirs among overlayfs mounts. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-04ovl: move cache and version to ovl_inodeMiklos Szeredi3-17/+13
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-04ovl: use ovl_inode mutex to synchronize concurrent copy upAmir Goldstein3-20/+11
Use the new ovl_inode mutex to synchonize concurrent copy up instead of the super block copy up workqueue. Moving the synchronization object from the overlay dentry to the overlay inode is needed for synchonizing concurrent copy up of lower hardlinks to the same upper inode. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-04ovl: move impure to ovl_inodeMiklos Szeredi6-17/+26
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-04ovl: move redirect to ovl_inodeMiklos Szeredi4-9/+9
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-04ovl: move __upperdentry to ovl_inodeMiklos Szeredi8-94/+79
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-04ovl: compare inodesMiklos Szeredi1-4/+9
When checking for consistency in directory operations (unlink, rename, etc.) match inodes not dentries. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-04ovl: use i_private only as a keyMiklos Szeredi5-20/+37
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-04ovl: simplify getting inodeMiklos Szeredi5-37/+36
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-04ovl: allocate an ovl_inode structAmir Goldstein2-2/+63
We need some more space to store overlay inode data in memory, so allocate overlay inodes from a slab of struct ovl_inode. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-04ovl: fix nlink leak in ovl_rename()Amir Goldstein1-0/+7
This patch fixes an overlay inode nlink leak in the case where ovl_rename() renames over a non-dir. This is not so critical, because overlay inode doesn't rely on nlink dropping to zero for inode deletion. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-04Merge tag 'uuid-for-4.13' of git://git.infradead.org/users/hch/uuid into ↵Miklos Szeredi3-6/+5
overlayfs-next UUID/GUID updates: - introduce the new uuid_t/guid_t types that are going to replace the somewhat confusing uuid_be/uuid_le types and make the terminology fit the various specs, as well as the userspace libuuid library. (me, based on a previous version from Amir) - consolidated generic uuid/guid helper functions lifted from XFS and libnvdimm (Amir and me) - conversions to the new types and helpers (Amir, Andy and me)