Hi Christoph, Here are redo-ed comments of your suggestions... On Thu, Aug 29, 2019 at 03:24:26AM -0700, Christoph Hellwig wrote: > On Fri, Aug 02, 2019 at 08:53:28PM +0800, Gao Xiang wrote: > > This adds core functions to get, read an inode. > > It adds statx support as well. > > > > Signed-off-by: Gao Xiang <gaoxiang25@xxxxxxxxxx> > > --- > > fs/erofs/inode.c | 291 +++++++++++++++++++++++++++++++++++++++++++++++ > > 1 file changed, 291 insertions(+) > > create mode 100644 fs/erofs/inode.c > > > > diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c > > new file mode 100644 > > index 000000000000..b6ea997bc4ae > > --- /dev/null > > +++ b/fs/erofs/inode.c > > @@ -0,0 +1,291 @@ > > +// SPDX-License-Identifier: GPL-2.0-only > > +/* > > + * linux/fs/erofs/inode.c > > + * > > + * Copyright (C) 2017-2018 HUAWEI, Inc. > > + * http://www.huawei.com/ > > + * Created by Gao Xiang <gaoxiang25@xxxxxxxxxx> > > + */ > > +#include "internal.h" > > + > > +#include <trace/events/erofs.h> > > + > > +/* no locking */ > > +static int read_inode(struct inode *inode, void *data) > > +{ > > + struct erofs_vnode *vi = EROFS_V(inode); > > + struct erofs_inode_v1 *v1 = data; > > + const unsigned int advise = le16_to_cpu(v1->i_advise); > > + erofs_blk_t nblks = 0; > > + > > + vi->datamode = __inode_data_mapping(advise); > > What is the deal with these magic underscores here and various > other similar helpers? Fixed in https://lore.kernel.org/linux-fsdevel/20190901055130.30572-17-hsiangkao@xxxxxxx/ underscores means 'internal' in my thought, it seems somewhat some common practice of Linux kernel, or some recent discussions about it?... I didn't notice these discussions... > > > + /* fast symlink (following ext4) */ > > This actually originates in FFS. But it is so common that the comment > seems a little pointless. Fixed in https://lore.kernel.org/linux-fsdevel/20190901055130.30572-9-hsiangkao@xxxxxxx/ > > > + if (S_ISLNK(inode->i_mode) && inode->i_size < PAGE_SIZE) { > > + char *lnk = erofs_kmalloc(sbi, inode->i_size + 1, GFP_KERNEL); > > Please just use plain kmalloc everywhere and let the normal kernel > error injection code take care of injeting any errors. Fixed in https://lore.kernel.org/linux-fsdevel/20190901055130.30572-20-hsiangkao@xxxxxxx/ > > > + /* inline symlink data shouldn't across page boundary as well */ > > ... should not cross .. Fixed in https://lore.kernel.org/linux-fsdevel/20190901055130.30572-9-hsiangkao@xxxxxxx/ > > > + if (unlikely(m_pofs + inode->i_size > PAGE_SIZE)) { > > + DBG_BUGON(1); > > + kfree(lnk); > > + return -EIO; > > + } > > + > > + /* get in-page inline data */ > > s/get/copy/, but the comment seems rather pointless. Fixed in https://lore.kernel.org/linux-fsdevel/20190901055130.30572-9-hsiangkao@xxxxxxx/ > > > + memcpy(lnk, data + m_pofs, inode->i_size); > > + lnk[inode->i_size] = '\0'; > > + > > + inode->i_link = lnk; > > + set_inode_fast_symlink(inode); > > Please just set the ops directly instead of obsfucating that in a single > caller, single line inline function. And please set it instead of the > normal symlink iops in the same place where you also set those.:w Fixed in https://lore.kernel.org/linux-fsdevel/20190901055130.30572-10-hsiangkao@xxxxxxx/ > > > + err = read_inode(inode, data + ofs); > > + if (!err) { > > if (err) > goto out_unlock; > > .. and save one level of indentation. Fixed in https://lore.kernel.org/linux-fsdevel/20190901055130.30572-22-hsiangkao@xxxxxxx/ > > > + if (is_inode_layout_compression(inode)) { > > The name of this helper is a little odd. But I think just > opencoding it seems generally cleaner anyway. Fixed in https://lore.kernel.org/linux-fsdevel/20190901055130.30572-11-hsiangkao@xxxxxxx/ > > > > + err = -ENOTSUPP; > > + goto out_unlock; > > + } > > + > > + inode->i_mapping->a_ops = &erofs_raw_access_aops; > > + > > + /* fill last page if inline data is available */ > > + err = fill_inline_data(inode, data, ofs); > > Well, I think you should move the is_inode_flat_inline and > (S_ISLNK(inode->i_mode) && inode->i_size < PAGE_SIZE) checks from that > helper here, as otherwise you make everyone wonder why you'd always > fill out the inline data. fill_inline_data is killed, and the similar function turns into erofs_fill_symlink which is called at erofs_fill_inode(): case S_IFLNK: - /* by default, page_get_link is used for symlink */ - inode->i_op = &erofs_symlink_iops; + err = erofs_fill_symlink(inode, data, ofs); + if (err) + goto out_unlock; inode_nohighmem(inode); break; > > > +static inline struct inode *erofs_iget_locked(struct super_block *sb, > > + erofs_nid_t nid) > > +{ > > + const unsigned long hashval = erofs_inode_hash(nid); > > + > > +#if BITS_PER_LONG >= 64 > > + /* it is safe to use iget_locked for >= 64-bit platform */ > > + return iget_locked(sb, hashval); > > +#else > > + return iget5_locked(sb, hashval, erofs_ilookup_test_actor, > > + erofs_iget_set_actor, &nid); > > +#endif > > Just use the slightly more complicated 32-bit version everywhere so that > you have a single actually tested code path. And then remove this > helper. As I said before, 64-bit platforms is common currently, I think iget_locked is enough. https://lore.kernel.org/r/20190830184606.GA175612@architecture4/ Thanks, Gao Xiang
