diff options
Diffstat (limited to 'fs/overlayfs/super.c')
-rw-r--r-- | fs/overlayfs/super.c | 67 |
1 files changed, 48 insertions, 19 deletions
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index cc8977498c48..3fa2416264a4 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -32,6 +32,7 @@ static struct dentry *ovl_d_real(struct dentry *dentry, const struct inode *inode) { struct dentry *real = NULL, *lower; + int err; /* It's an overlay file */ if (inode && d_inode(dentry) == inode) @@ -58,7 +59,9 @@ static struct dentry *ovl_d_real(struct dentry *dentry, * uprobes on offset within the file, so lowerdata should be available * when setting the uprobe. */ - ovl_maybe_lookup_lowerdata(dentry); + err = ovl_verify_lowerdata(dentry); + if (err) + goto bug; lower = ovl_dentry_lowerdata(dentry); if (!lower) goto bug; @@ -101,8 +104,8 @@ 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; @@ -112,6 +115,8 @@ 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); @@ -164,6 +169,7 @@ 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); } @@ -173,7 +179,7 @@ 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 @@ -182,7 +188,7 @@ static void ovl_destroy_inode(struct inode *inode) static void ovl_put_super(struct super_block *sb) { - struct ovl_fs *ofs = sb->s_fs_info; + struct ovl_fs *ofs = OVL_FS(sb); if (ofs) ovl_free_fs(ofs); @@ -191,7 +197,7 @@ static void ovl_put_super(struct super_block *sb) /* Sync real dirty inodes in upper filesystem (if it exists) */ static int ovl_sync_fs(struct super_block *sb, int wait) { - struct ovl_fs *ofs = sb->s_fs_info; + struct ovl_fs *ofs = OVL_FS(sb); struct super_block *upper_sb; int ret; @@ -239,8 +245,9 @@ static int ovl_sync_fs(struct super_block *sb, int wait) */ static int ovl_statfs(struct dentry *dentry, struct kstatfs *buf) { - struct ovl_fs *ofs = dentry->d_sb->s_fs_info; - struct dentry *root_dentry = dentry->d_sb->s_root; + struct super_block *sb = dentry->d_sb; + struct ovl_fs *ofs = OVL_FS(sb); + struct dentry *root_dentry = sb->s_root; struct path path; int err; @@ -250,6 +257,8 @@ static int ovl_statfs(struct dentry *dentry, struct kstatfs *buf) if (!err) { buf->f_namelen = ofs->namelen; buf->f_type = OVERLAYFS_SUPER_MAGIC; + if (ovl_has_fsid(ofs)) + buf->f_fsid = uuid_to_fsid(sb->s_uuid.b); } return err; @@ -397,6 +406,7 @@ static int ovl_lower_dir(const char *name, struct path *path, pr_warn("fs on '%s' does not support file handles, falling back to index=off,nfs_export=off.\n", name); } + ofs->nofh |= !fh_type; /* * Decoding origin file handle is required for persistent st_ino. * Without persistent st_ino, xino=auto falls back to xino=off. @@ -562,11 +572,6 @@ 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. * @@ -770,6 +775,10 @@ static int ovl_make_workdir(struct super_block *sb, struct ovl_fs *ofs, ofs->config.index = false; pr_warn("...falling back to index=off.\n"); } + if (ovl_has_fsid(ofs)) { + ofs->config.uuid = OVL_UUID_NULL; + pr_warn("...falling back to uuid=null.\n"); + } /* * xattr support is required for persistent st_ino. * Without persistent st_ino, xino=auto falls back to xino=off. @@ -815,6 +824,7 @@ static int ovl_make_workdir(struct super_block *sb, struct ovl_fs *ofs, ofs->config.index = false; pr_warn("upper fs does not support file handles, falling back to index=off.\n"); } + ofs->nofh |= !fh_type; /* Check if upper fs has 32bit inode numbers */ if (fh_type != FILEID_INO32_GEN) @@ -1110,7 +1120,8 @@ 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; @@ -1355,8 +1366,16 @@ 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; @@ -1416,9 +1435,12 @@ int ovl_fill_super(struct super_block *sb, struct fs_context *fc) if (!ovl_upper_mnt(ofs)) sb->s_flags |= SB_RDONLY; - if (!ofs->config.uuid && ofs->numfs > 1) { - pr_warn("The uuid=off requires a single fs for lower and upper, falling back to uuid=on.\n"); - ofs->config.uuid = true; + if (!ovl_origin_uuid(ofs) && ofs->numfs > 1) { + pr_warn("The uuid=off requires a single fs for lower and upper, falling back to uuid=null.\n"); + ofs->config.uuid = OVL_UUID_NULL; + } else if (ovl_has_fsid(ofs) && ovl_upper_mnt(ofs)) { + /* Use per instance persistent uuid/fsid */ + ovl_init_uuid_xattr(sb, ofs, &ctx->upper); } if (!ovl_force_readonly(ofs) && ofs->config.index) { @@ -1449,8 +1471,15 @@ int ovl_fill_super(struct super_block *sb, struct fs_context *fc) ofs->config.nfs_export = false; } + /* + * Support encoding decodable file handles with nfs_export=on + * and encoding non-decodable file handles with nfs_export=off + * if all layers support file handles. + */ if (ofs->config.nfs_export) sb->s_export_op = &ovl_export_operations; + else if (!ofs->nofh) + sb->s_export_op = &ovl_export_fid_operations; /* Never override disk quota limits or use reserved space */ cap_lower(cred->cap_effective, CAP_SYS_RESOURCE); @@ -1479,7 +1508,7 @@ out_err: return err; } -static struct file_system_type ovl_fs_type = { +struct file_system_type ovl_fs_type = { .owner = THIS_MODULE, .name = "overlay", .init_fs_context = ovl_init_fs_context, |