kernel.git/fs/overlayfs/util.c, branch linux-4.18.y

ovl: fix memory leak on unlink of indexed file

2018-10-10T06:56:04Z

commit 63e132528032ce937126aba591a7b37ec593a6bb upstream. The memory leak was detected by kmemleak when running xfstests overlay/051,053 Fixes: caf70cb2ba5d ("ovl: cleanup orphan index entries") Cc: # v4.13 Signed-off-by: Amir Goldstein Signed-off-by: Miklos Szeredi Signed-off-by: Greg Kroah-Hartman

ovl: constant st_ino for non-samefs with xino

2018-04-12T10:04:50Z

On 64bit systems, when overlay layers are not all on the same fs, but all inode numbers of underlying fs are not using the high bits, use the high bits to partition the overlay st_ino address space. The high bits hold the fsid (upper fsid is 0). This way overlay inode numbers are unique and all inodes use overlay st_dev. Inode numbers are also persistent for a given layer configuration. Currently, our only indication for available high ino bits is from a filesystem that supports file handles and uses the default encode_fh() operation, which encodes a 32bit inode number. Signed-off-by: Amir Goldstein Signed-off-by: Miklos Szeredi

ovl: allocate anon bdev per unique lower fs

2018-04-12T10:04:50Z

Instead of allocating an anonymous bdev per lower layer, allocate one anonymous bdev per every unique lower fs that is different than upper fs. Every unique lower fs is assigned an fsid > 0 and the number of unique lower fs are stored in ofs->numlowerfs. The assigned fsid is stored in the lower layer struct and will be used also for inode number multiplexing. Signed-off-by: Amir Goldstein Signed-off-by: Miklos Szeredi

ovl: factor out ovl_map_dev_ino() helper

2018-04-12T10:04:50Z

A helper for ovl_getattr() to map the values of st_dev and st_ino according to constant st_ino rules. Signed-off-by: Amir Goldstein Signed-off-by: Miklos Szeredi

ovl: set i_ino to the value of st_ino for NFS export

2018-04-12T10:04:48Z

Eddie Horng reported that readdir of an overlayfs directory that was exported via NFSv3 returns entries with d_type set to DT_UNKNOWN. The reason is that while preparing the response for readdirplus, nfsd checks inside encode_entryplus_baggage() that a child dentry's inode number matches the value of d_ino returns by overlayfs readdir iterator. Because the overlayfs inodes use arbitrary inode numbers that are not correlated with the values of st_ino/d_ino, NFSv3 falls back to not encoding d_type. Although this is an allowed behavior, we can fix it for the case of all overlayfs layers on the same underlying filesystem. When NFS export is enabled and d_ino is consistent with st_ino (samefs), set the same value also to i_ino in ovl_fill_inode() for all overlayfs inodes, nfsd readdirplus sanity checks will pass. ovl_fill_inode() may be called from ovl_new_inode(), before real inode was created with ino arg 0. In that case, i_ino will be updated to real upper inode i_ino on ovl_inode_init() or ovl_inode_update(). Reported-by: Eddie Horng Tested-by: Eddie Horng Signed-off-by: Amir Goldstein Fixes: 8383f1748829 ("ovl: wire up NFS export operations") Cc: #v4.16 Signed-off-by: Miklos Szeredi

ovl: store 'has_upper' and 'opaque' as bit flags

2018-01-24T10:25:58Z

We need to make some room in struct ovl_entry to store information about redirected ancestors for NFS export, so cram two booleans as bit flags. Signed-off-by: Amir Goldstein Signed-off-by: Miklos Szeredi

ovl: copy up of disconnected dentries

2018-01-24T10:25:58Z

With NFS export, some operations on decoded file handles (e.g. open, link, setattr, xattr_set) may call copy up with a disconnected non-dir. In this case, we will copy up lower inode to index dir without linking it to upper dir. Signed-off-by: Amir Goldstein Signed-off-by: Miklos Szeredi

ovl: whiteout index when union nlink drops to zero

2018-01-24T10:25:56Z

With NFS export feature enabled, when overlay inode nlink drops to zero, instead of removing the index entry, replace it with a whiteout index entry. This is needed for NFS export in order to prevent future open by handle from opening the lower file directly. Signed-off-by: Amir Goldstein Signed-off-by: Miklos Szeredi

ovl: cleanup dir index when dir nlink drops to zero

2018-01-24T10:25:55Z

When non-dir index union nlink drops to zero the non-dir index is cleaned. Do the same for directory type index entries when union directory is removed. Signed-off-by: Amir Goldstein Signed-off-by: Miklos Szeredi

ovl: index directories on copy up for NFS export

2018-01-24T10:25:55Z

With the NFS export feature enabled, all dirs are indexed on copy up. Non-dir files are copied up directly to indexdir and then hardlinked to upper dir. Directories are copied up to indexdir, then an index entry is created in indexdir with 'upper' xattr pointing to the copied up dir and then the copied up dir is moved to upper dir. Directory index is also used for consistency verification, like detecting multiple redirected dirs to the same lower dir on lookup. Signed-off-by: Amir Goldstein Signed-off-by: Miklos Szeredi