From: Vivek Goyal <[email protected]> Set redirect on metacopy files upon rename. This will help find data dentry in lower dirs.
Signed-off-by: Vivek Goyal <[email protected]> Reviewed-by: Amir Goldstein <[email protected]> Signed-off-by: Miklos Szeredi <[email protected]> --- fs/overlayfs/dir.c | 66 +++++++++++++++++++++++++++++++++++++----------------- 1 file changed, 46 insertions(+), 20 deletions(-) diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c index 8d8e063e4706..1658961a9762 100644 --- a/fs/overlayfs/dir.c +++ b/fs/overlayfs/dir.c @@ -873,13 +873,13 @@ static bool ovl_can_move(struct dentry *dentry) !d_is_dir(dentry) || !ovl_type_merge_or_lower(dentry); } -static char *ovl_get_redirect(struct dentry *dentry, bool samedir) +static char *ovl_get_redirect(struct dentry *dentry, bool abs_redirect) { char *buf, *ret; struct dentry *d, *tmp; int buflen = ovl_redirect_max + 1; - if (samedir) { + if (!abs_redirect) { ret = kstrndup(dentry->d_name.name, dentry->d_name.len, GFP_KERNEL); goto out; @@ -933,15 +933,43 @@ static char *ovl_get_redirect(struct dentry *dentry, bool samedir) return ret ? ret : ERR_PTR(-ENOMEM); } +static bool ovl_need_absolute_redirect(struct dentry *dentry, bool samedir) +{ + struct dentry *lowerdentry; + + if (!samedir) + return true; + + if (d_is_dir(dentry)) + return false; + + /* + * For non-dir hardlinked files, we need absolute redirects + * in general as two upper hardlinks could be in different + * dirs. We could put a relative redirect now and convert + * it to absolute redirect later. But when nlink > 1 and + * indexing is on, that means relative redirect needs to be + * converted to absolute during copy up of another lower + * hardllink as well. + * + * So without optimizing too much, just check if lower is + * a hard link or not. If lower is hard link, put absolute + * redirect. + */ + lowerdentry = ovl_dentry_lower(dentry); + return (d_inode(lowerdentry)->i_nlink > 1); +} + static int ovl_set_redirect(struct dentry *dentry, bool samedir) { int err; const char *redirect = ovl_dentry_get_redirect(dentry); + bool absolute_redirect = ovl_need_absolute_redirect(dentry, samedir); - if (redirect && (samedir || redirect[0] == '/')) + if (redirect && (!absolute_redirect || redirect[0] == '/')) return 0; - redirect = ovl_get_redirect(dentry, samedir); + redirect = ovl_get_redirect(dentry, absolute_redirect); if (IS_ERR(redirect)) return PTR_ERR(redirect); @@ -1117,22 +1145,20 @@ static int ovl_rename(struct inode *olddir, struct dentry *old, goto out_dput; err = 0; - if (is_dir) { - if (ovl_type_merge_or_lower(old)) - err = ovl_set_redirect(old, samedir); - else if (!old_opaque && ovl_type_merge(new->d_parent)) - err = ovl_set_opaque_xerr(old, olddentry, -EXDEV); - if (err) - goto out_dput; - } - if (!overwrite && new_is_dir) { - if (ovl_type_merge_or_lower(new)) - err = ovl_set_redirect(new, samedir); - else if (!new_opaque && ovl_type_merge(old->d_parent)) - err = ovl_set_opaque_xerr(new, newdentry, -EXDEV); - if (err) - goto out_dput; - } + if (ovl_type_merge_or_lower(old)) + err = ovl_set_redirect(old, samedir); + else if (is_dir && !old_opaque && ovl_type_merge(new->d_parent)) + err = ovl_set_opaque_xerr(old, olddentry, -EXDEV); + if (err) + goto out_dput; + + if (!overwrite && ovl_type_merge_or_lower(new)) + err = ovl_set_redirect(new, samedir); + else if (!overwrite && new_is_dir && !new_opaque && + ovl_type_merge(old->d_parent)) + err = ovl_set_opaque_xerr(new, newdentry, -EXDEV); + if (err) + goto out_dput; err = ovl_do_rename(old_upperdir->d_inode, olddentry, new_upperdir->d_inode, newdentry, flags); -- 2.14.3
