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| author | Amir Goldstein <amir73il@gmail.com> | 2018-03-15 23:39:01 +0200 |
|---|---|---|
| committer | Miklos Szeredi <mszeredi@redhat.com> | 2018-04-12 12:04:48 +0200 |
| commit | 695b46e76b62447e506cddc87e088236498008e5 (patch) | |
| tree | 522f7a910302f5879915ebb19352632c4fdc1a5f /fs/overlayfs/util.c | |
| parent | 3eb2ce825ea1ad89d20f7a3b5780df850e4be274 (diff) | |
| download | linux-695b46e76b62447e506cddc87e088236498008e5.tar.bz2 | |
ovl: set i_ino to the value of st_ino for NFS export
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 <eddiehorng.tw@gmail.com>
Tested-by: Eddie Horng <eddiehorng.tw@gmail.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Fixes: 8383f1748829 ("ovl: wire up NFS export operations")
Cc: <stable@vger.kernel.org> #v4.16
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Diffstat (limited to 'fs/overlayfs/util.c')
| -rw-r--r-- | fs/overlayfs/util.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c index 930784a26623..493f9b76fbf6 100644 --- a/fs/overlayfs/util.c +++ b/fs/overlayfs/util.c @@ -279,12 +279,16 @@ void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect) void ovl_inode_init(struct inode *inode, struct dentry *upperdentry, struct dentry *lowerdentry) { + struct inode *realinode = d_inode(upperdentry ?: lowerdentry); + if (upperdentry) OVL_I(inode)->__upperdentry = upperdentry; if (lowerdentry) OVL_I(inode)->lower = igrab(d_inode(lowerdentry)); - ovl_copyattr(d_inode(upperdentry ?: lowerdentry), inode); + ovl_copyattr(realinode, inode); + if (!inode->i_ino) + inode->i_ino = realinode->i_ino; } void ovl_inode_update(struct inode *inode, struct dentry *upperdentry) @@ -299,6 +303,8 @@ void ovl_inode_update(struct inode *inode, struct dentry *upperdentry) smp_wmb(); OVL_I(inode)->__upperdentry = upperdentry; if (inode_unhashed(inode)) { + if (!inode->i_ino) + inode->i_ino = upperinode->i_ino; inode->i_private = upperinode; __insert_inode_hash(inode, (unsigned long) upperinode); } |