diff options
Diffstat (limited to 'fs/overlayfs/super.c')
| -rw-r--r-- | fs/overlayfs/super.c | 55 |
1 files changed, 39 insertions, 16 deletions
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index def266b5e2a3..6cd949c59fed 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -34,14 +34,22 @@ static struct dentry *ovl_d_real(struct dentry *dentry, struct dentry *real = NULL, *lower; int err; - /* It's an overlay file */ + /* + * vfs is only expected to call d_real() with NULL from d_real_inode() + * and with overlay inode from file_dentry() on an overlay file. + * + * TODO: remove @inode argument from d_real() API, remove code in this + * function that deals with non-NULL @inode and remove d_real() call + * from file_dentry(). + */ if (inode && d_inode(dentry) == inode) return dentry; + else if (inode) + goto bug; if (!d_is_reg(dentry)) { - if (!inode || inode == d_inode(dentry)) - return dentry; - goto bug; + /* d_real_inode() is only relevant for regular files */ + return dentry; } real = ovl_dentry_upper(dentry); @@ -104,8 +112,8 @@ static int ovl_revalidate_real(struct dentry *d, unsigned int flags, bool weak) static int ovl_dentry_revalidate_common(struct dentry *dentry, unsigned int flags, bool weak) { - struct ovl_entry *oe = OVL_E(dentry); - struct ovl_path *lowerstack = ovl_lowerstack(oe); + struct ovl_entry *oe; + struct ovl_path *lowerstack; struct inode *inode = d_inode_rcu(dentry); struct dentry *upper; unsigned int i; @@ -115,6 +123,8 @@ static int ovl_dentry_revalidate_common(struct dentry *dentry, if (!inode) return -ECHILD; + oe = OVL_I_E(inode); + lowerstack = ovl_lowerstack(oe); upper = ovl_i_dentry_upper(inode); if (upper) ret = ovl_revalidate_real(upper, flags, weak); @@ -167,6 +177,7 @@ static void ovl_free_inode(struct inode *inode) struct ovl_inode *oi = OVL_I(inode); kfree(oi->redirect); + kfree(oi->oe); mutex_destroy(&oi->lock); kmem_cache_free(ovl_inode_cachep, oi); } @@ -176,7 +187,7 @@ static void ovl_destroy_inode(struct inode *inode) struct ovl_inode *oi = OVL_I(inode); dput(oi->__upperdentry); - ovl_free_entry(oi->oe); + ovl_stack_put(ovl_lowerstack(oi->oe), ovl_numlower(oi->oe)); if (S_ISDIR(inode->i_mode)) ovl_dir_cache_free(inode); else @@ -484,13 +495,13 @@ static const struct xattr_handler ovl_other_xattr_handler = { .set = ovl_other_xattr_set, }; -static const struct xattr_handler *ovl_trusted_xattr_handlers[] = { +static const struct xattr_handler * const ovl_trusted_xattr_handlers[] = { &ovl_own_trusted_xattr_handler, &ovl_other_xattr_handler, NULL }; -static const struct xattr_handler *ovl_user_xattr_handlers[] = { +static const struct xattr_handler * const ovl_user_xattr_handlers[] = { &ovl_own_user_xattr_handler, &ovl_other_xattr_handler, NULL @@ -569,11 +580,6 @@ static int ovl_get_upper(struct super_block *sb, struct ovl_fs *ofs, upper_layer->idx = 0; upper_layer->fsid = 0; - err = -ENOMEM; - upper_layer->name = kstrdup(ofs->config.upperdir, GFP_KERNEL); - if (!upper_layer->name) - goto out; - /* * Inherit SB_NOSEC flag from upperdir. * @@ -1122,7 +1128,8 @@ static int ovl_get_layers(struct super_block *sb, struct ovl_fs *ofs, layers[ofs->numlayer].idx = ofs->numlayer; layers[ofs->numlayer].fsid = fsid; layers[ofs->numlayer].fs = &ofs->fs[fsid]; - layers[ofs->numlayer].name = l->name; + /* Store for printing lowerdir=... in ovl_show_options() */ + ofs->config.lowerdirs[ofs->numlayer] = l->name; l->name = NULL; ofs->numlayer++; ofs->fs[fsid].is_lower = true; @@ -1367,8 +1374,16 @@ int ovl_fill_super(struct super_block *sb, struct fs_context *fc) if (!layers) goto out_err; + ofs->config.lowerdirs = kcalloc(ctx->nr + 1, sizeof(char *), GFP_KERNEL); + if (!ofs->config.lowerdirs) { + kfree(layers); + goto out_err; + } ofs->layers = layers; - /* Layer 0 is reserved for upper even if there's no upper */ + /* + * Layer 0 is reserved for upper even if there's no upper. + * For consistency, config.lowerdirs[0] is NULL. + */ ofs->numlayer = 1; sb->s_stack_depth = 0; @@ -1481,8 +1496,16 @@ int ovl_fill_super(struct super_block *sb, struct fs_context *fc) sb->s_xattr = ofs->config.userxattr ? ovl_user_xattr_handlers : ovl_trusted_xattr_handlers; sb->s_fs_info = ofs; +#ifdef CONFIG_FS_POSIX_ACL sb->s_flags |= SB_POSIXACL; +#endif sb->s_iflags |= SB_I_SKIP_SYNC | SB_I_IMA_UNVERIFIABLE_SIGNATURE; + /* + * Ensure that umask handling is done by the filesystems used + * for the the upper layer instead of overlayfs as that would + * lead to unexpected results. + */ + sb->s_iflags |= SB_I_NOUMASK; err = -ENOMEM; root_dentry = ovl_get_root(sb, ctx->upper.dentry, oe); |