erofs: support compressed inodes over fscache

Since fscache can utilize iov_iter to write dest buffers, bio_vec can
be used in this way too.

To simplify this, pseudo bios are prepared and bio_vec will be filled
with bio_add_page(). And a common .bi_end_io will be called directly
to handle I/O completions.

Signed-off-by: Jingbo Xu <jefflexu@linux.alibaba.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20240308094159.40547-2-jefflexu@linux.alibaba.com
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

erofs: get rid of unneeded GFP_NOFS

Clean up some leftovers since there is no way for EROFS to be called
again from a reclaim context.

Signed-off-by: Jingbo Xu <jefflexu@linux.alibaba.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20240124031945.130782-1-jefflexu@linux.alibaba.com
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

erofs: enable sub-page compressed block support

Let's just disable cached decompression and inplace I/Os for partial
pages as the first step in order to enable sub-page block initial
support. In other words, currently it works primarily based on
temporary short-lived pages. Don't expect too much in terms of
performance.

Reviewed-by: Yue Hu <huyue2@coolpad.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20231206091057.87027-6-hsiangkao@linux.alibaba.com

erofs: simplify erofs_read_inode()

After commit 1c7f49a76773 ("erofs: tidy up EROFS on-disk naming"),
there is a unique `union erofs_inode_i_u` so that we could parse
the union directly.

Besides, it also replaces `inode->i_sb` with `sb` for simplicity.

Signed-off-by: Ferry Meng <mengferry@linux.alibaba.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: Yue Hu <huyue2@coolpad.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Link: https://lore.kernel.org/r/20231109111822.17944-1-mengferry@linux.alibaba.com
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

erofs: convert to new timestamp accessors

Convert to using the new inode timestamp accessor functions.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://lore.kernel.org/r/20231004185347.80880-30-jlayton@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>

fs: pass the request_mask to generic_fillattr

generic_fillattr just fills in the entire stat struct indiscriminately
today, copying data from the inode. There is at least one attribute
(STATX_CHANGE_COOKIE) that can have side effects when it is reported,
and we're looking at adding more with the addition of multigrain
timestamps.

Add a request_mask argument to generic_fillattr and have most callers
just pass in the value that is passed to getattr. Have other callers
(e.g. ksmbd) just pass in STATX_BASIC_STATS. Also move the setting of
STATX_CHANGE_COOKIE into generic_fillattr.

Acked-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Reviewed-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: "Paulo Alcantara (SUSE)" <pc@manguebit.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Message-Id: <20230807-mgctime-v7-2-d1dec143a704@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>

erofs: convert to ctime accessor functions

In later patches, we're going to change how the inode's ctime field is
used. Switch to using accessor functions instead of raw accesses of
inode->i_ctime.

Acked-by: Gao Xiang <xiang@kernel.org>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Message-Id: <20230705190309.579783-37-jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>

erofs: fix fsdax unavailability for chunk-based regular files

DAX can be used to share page cache between VMs, reducing guest memory
overhead. And chunk based data format is widely used for VM and
container image. So enable dax support for it, make erofs better used
for VM scenarios.

Fixes: c5aa903a59db ("erofs: support reading chunk-based uncompressed files")
Signed-off-by: Xin Yin <yinxin.x@bytedance.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Link: https://lore.kernel.org/r/20230711062130.7860-1-yinxin.x@bytedance.com
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

erofs: sunset erofs_dbg()

Such debug messages are rarely used now. Let's get rid of these,
and revert locally if they are needed for debugging.

Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Link: https://lore.kernel.org/r/20230414083027.12307-1-hsiangkao@linux.alibaba.com

erofs: get rid of z_erofs_fill_inode()

Prior to big pclusters, non-compact compression indexes could have
empty headers.

Let's just avoid the legacy path since it can be handled properly
as a specific compression header with z_erofs_fill_inode_lazy() too.

Tested with erofs-utils exist versions.

Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: Yue Hu <huyue2@coolpad.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Link: https://lore.kernel.org/r/20230413092241.73829-1-hsiangkao@linux.alibaba.com

erofs: set block size to the on-disk block size

Set the block size to that specified in on-disk superblock.

Also remove the hard constraint of PAGE_SIZE block size for the
uncompressed device backend. This constraint is temporarily remained
for compressed device and fscache backend, as there is more work needed
to handle the condition where the block size is not equal to PAGE_SIZE.

It is worth noting that the on-disk block size is read prior to
erofs_superblock_csum_verify(), as the read block size is needed in the
latter.

Besides, later we are going to make erofs refer to tar data blobs (which
is 512-byte aligned) for OCI containers, where the block size is 512
bytes. In this case, the 512-byte block size may not be adequate for a
directory to contain enough dirents. To fix this, we are also going to
introduce directory block size independent on the block size.

Due to we have already supported block size smaller than PAGE_SIZE now,
disable all these images with such separated directory block size until
we supported this feature later.

Signed-off-by: Jingbo Xu <jefflexu@linux.alibaba.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: Yue Hu <huyue2@coolpad.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Link: https://lore.kernel.org/r/20230313135309.75269-3-jefflexu@linux.alibaba.com
[ Gao Xiang: update documentation. ]
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

erofs: avoid hardcoded blocksize for subpage block support

As the first step of converting hardcoded blocksize to that specified in
on-disk superblock, convert all call sites of hardcoded blocksize to
sb->s_blocksize except for:

1) use sbi->blkszbits instead of sb->s_blocksize in
erofs_superblock_csum_verify() since sb->s_blocksize has not been
updated with the on-disk blocksize yet when the function is called.

2) use inode->i_blkbits instead of sb->s_blocksize in erofs_bread(),
since the inode operated on may be an anonymous inode in fscache mode.
Currently the anonymous inode is allocated from an anonymous mount
maintained in erofs, while in the near future we may allocate anonymous
inodes from a generic API directly and thus have no access to the
anonymous inode's i_sb. Thus we keep the block size in i_blkbits for
anonymous inodes in fscache mode.

Be noted that this patch only gets rid of the hardcoded blocksize, in
preparation for actually setting the on-disk block size in the following
patch. The hard limit of constraining the block size to PAGE_SIZE still
exists until the next patch.

Signed-off-by: Jingbo Xu <jefflexu@linux.alibaba.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: Yue Hu <huyue2@coolpad.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Link: https://lore.kernel.org/r/20230313135309.75269-2-jefflexu@linux.alibaba.com
[ Gao Xiang: fold a patch to fix incorrect truncated offsets. ]
Link: https://lore.kernel.org/r/20230413035734.15457-1-zhujia.zj@bytedance.com
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

erofs: simplify iloc()

Actually we could pass in inodes directly to clean up all callers.
Also rename iloc() as erofs_iloc().

Link: https://lore.kernel.org/r/20230114150823.432069-1-xiang@kernel.org
Reviewed-by: Yue Hu <huyue2@coolpad.com>
Reviewed-by: Jingbo Xu <jefflexu@linux.alibaba.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

erofs: clean up erofs_iget()

Move inode hash function into inode.c and simplify erofs_iget().

Link: https://lore.kernel.org/r/20230113065226.68801-1-hsiangkao@linux.alibaba.com
Reviewed-by: Yue Hu <huyue2@coolpad.com>
Reviewed-by: Jingbo Xu <jefflexu@linux.alibaba.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

fs: port ->getattr() to pass mnt_idmap

Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>

erofs: use kmap_local_page() only for erofs_bread()

Convert all mapped erofs_bread() users to use kmap_local_page()
instead of kmap() or kmap_atomic().

Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-and-tested-by: Jingbo Xu <jefflexu@linux.alibaba.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Link: https://lore.kernel.org/r/20221018105313.4940-1-hsiangkao@linux.alibaba.com
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

erofs: enable large folios for fscache mode

Enable large folios for fscache mode. Enable this feature for
non-compressed format for now, until the compression part supports large
folios later.

One thing worth noting is that, the feature is not enabled for the meta
data routine since meta inodes don't need large folios for now, nor do
they support readahead yet.

Also document this new feature.

Signed-off-by: Jingbo Xu <jefflexu@linux.alibaba.com>
Reviewed-by: Jia Zhu <zhujia.zj@bytedance.com>
Link: https://lore.kernel.org/r/20221201074256.16639-3-jefflexu@linux.alibaba.com
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

erofs: enable large folios for iomap mode

Enable large folios for iomap mode. Then the readahead routine will
pass down large folios containing multiple pages.

Let's enable this for non-compressed format for now, until the
compression part supports large folios later.

When large folios supported, the iomap routine will allocate iomap_page
for each large folio and thus we need iomap_release_folio() and
iomap_invalidate_folio() to free iomap_page when these folios get
reclaimed or invalidated.

Signed-off-by: Jingbo Xu <jefflexu@linux.alibaba.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Link: https://lore.kernel.org/r/20221130060455.44532-1-jefflexu@linux.alibaba.com
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

fs: rename current get acl method

The current way of setting and getting posix acls through the generic
xattr interface is error prone and type unsafe. The vfs needs to
interpret and fixup posix acls before storing or reporting it to
userspace. Various hacks exist to make this work. The code is hard to
understand and difficult to maintain in it's current form. Instead of
making this work by hacking posix acls through xattr handlers we are
building a dedicated posix acl api around the get and set inode
operations. This removes a lot of hackiness and makes the codepaths
easier to maintain. A lot of background can be found in [1].

The current inode operation for getting posix acls takes an inode
argument but various filesystems (e.g., 9p, cifs, overlayfs) need access
to the dentry. In contrast to the ->set_acl() inode operation we cannot
simply extend ->get_acl() to take a dentry argument. The ->get_acl()
inode operation is called from:

acl_permission_check()
-> check_acl()
-> get_acl()

which is part of generic_permission() which in turn is part of
inode_permission(). Both generic_permission() and inode_permission() are
called in the ->permission() handler of various filesystems (e.g.,
overlayfs). So simply passing a dentry argument to ->get_acl() would
amount to also having to pass a dentry argument to ->permission(). We
should avoid this unnecessary change.

So instead of extending the existing inode operation rename it from
->get_acl() to ->get_inode_acl() and add a ->get_acl() method later that
passes a dentry argument and which filesystems that need access to the
dentry can implement instead of ->get_inode_acl(). Filesystems like cifs
which allow setting and getting posix acls but not using them for
permission checking during lookup can simply not implement
->get_inode_acl().

This is intended to be a non-functional change.

Link: https://lore.kernel.org/all/20220801145520.1532837-1-brauner@kernel.org [1]
Suggested-by/Inspired-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>

erofs: clean up erofs_iget()

isdir indicated REQ_META|REQ_PRIO which no longer works now.
Get rid of isdir entirely.

Link: https://lore.kernel.org/r/20220927063607.54832-2-hsiangkao@linux.alibaba.com
Reviewed-by: Yue Hu <huyue2@coolpad.com>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

erofs: fix order >= MAX_ORDER warning due to crafted negative i_size

As syzbot reported [1], the root cause is that i_size field is a
signed type, and negative i_size is also less than EROFS_BLKSIZ.
As a consequence, it's handled as fast symlink unexpectedly.

Let's fall back to the generic path to deal with such unusual i_size.

[1] https://lore.kernel.org/r/000000000000ac8efa05e7feaa1f@google.com

Reported-by: syzbot+f966c13b1b4fc0403b19@syzkaller.appspotmail.com
Fixes: 431339ba9042 ("staging: erofs: add inode operations")
Reviewed-by: Yue Hu <huyue2@coolpad.com>
Link: https://lore.kernel.org/r/20220909023948.28925-1-hsiangkao@linux.alibaba.com
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

erofs: leave compressed inodes unsupported in fscache mode for now

erofs over fscache doesn't support the compressed layout yet. It will
cause NULL crash if there are compressed inodes contained when working
in fscache mode.

So far in the erofs based container image distribution scenarios
(RAFS v6), the compressed RAFS v6 images are downloaded and then
decompressed on demand as an uncompressed erofs image. Then the erofs
image is mounted in fscache mode for containers to use. IOWs, currently
compressed data is decompressed on the userspace side instead and
uncompressed erofs images will be finally cached.

The fscache support for the compressed layout is still under
development and it will be used for runtime decompression feature.
Anyway, to avoid the potential crash, let's leave the compressed inodes
unsupported in fscache mode until we support it later.

Fixes: 1442b02b66ad ("erofs: implement fscache-based data read for non-inline layout")
Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Link: https://lore.kernel.org/r/20220526010344.118493-1-jefflexu@linux.alibaba.com
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

erofs: implement fscache-based data read for non-inline layout

Implement the data plane of reading data from data blobs over fscache
for non-inline layout.

Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20220425122143.56815-19-jefflexu@linux.alibaba.com
Acked-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

erofs: support idmapped mounts

This patch enables idmapped mounts for erofs, since all dedicated helpers
for this functionality existsm, so, in this patch we just pass down the
user_namespace argument from the VFS methods to the relevant helpers.

Simple idmap example on erofs image:

1. mkdir dir
2. touch dir/file
3. mkfs.erofs erofs.img dir
4. mount -t erofs -o loop erofs.img /mnt/erofs/

5. ls -ln /mnt/erofs/
total 0
-rw-rw-r-- 1 1000 1000 0 May 17 15:26 file

6. mount-idmapped --map-mount b:1000:1001:1 /mnt/erofs/ /mnt/scratch_erofs/

7. ls -ln /mnt/scratch_erofs/
total 0
-rw-rw-r-- 1 1001 1001 0 May 17 15:26 file

Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Signed-off-by: Chao Yu <chao.yu@oppo.com>
Link: https://lore.kernel.org/r/20220517104103.3570721-1-chao@kernel.org
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

erofs: remove obsoleted comments

Some comments haven't been useful anymore since the code updated.
Let's drop them instead.

Link: https://lore.kernel.org/r/20220506194612.117120-2-hsiangkao@linux.alibaba.com
Reviewed-by: Yue Hu <huyue2@coolpad.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

erofs: rename ctime to mtime

EROFS images should inherit modification time rather than change time,
since users and host tooling have no easy way to control change time.

To reflect the new timestamp meaning, i_ctime and i_ctime_nsec are
renamed to i_mtime and i_mtime_nsec.

Link: https://lore.kernel.org/r/20220311041829.3109511-1-dvander@google.com # v1
Signed-off-by: David Anderson <dvander@google.com>
[ Gao Xiang: update document as well. ]
Reviewed-by: Chao Yu <chao@kernel.org>
Link: https://lore.kernel.org/r/20220317114959.106787-1-hsiangkao@linux.alibaba.com # v2
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

erofs: use meta buffers for inode operations

Get rid of old erofs_get_meta_page() within inode operations by
using on-stack meta buffers in order to prepare subpage and folio
features.

Link: https://lore.kernel.org/r/20220102040017.51352-3-hsiangkao@linux.alibaba.com
Reviewed-by: Yue Hu <huyue2@yulong.com>
Reviewed-by: Liu Bo <bo.liu@linux.alibaba.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

erofs: decouple basic mount options from fs_context

Previously, EROFS mount options are all in the basic types, so
erofs_fs_context can be directly copied with assignment. However,
when the multiple device feature is introduced, it's hard to handle
multiple device information like the other basic mount options.

Let's separate basic mount option usage from fs_context, thus
multiple device information can be handled gracefully then.

No logic changes.

Link: https://lore.kernel.org/r/20211007070224.12833-1-hsiangkao@linux.alibaba.com
Reviewed-by: Chao Yu <chao@kernel.org>
Reviewed-by: Liu Bo <bo.liu@linux.alibaba.com>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

erofs: fix misbehavior of unsupported chunk format check

Unsupported chunk format should be checked with
"if (vi->chunkformat & ~EROFS_CHUNK_FORMAT_ALL)"

Found when checking with 4k-byte blockmap (although currently mkfs
uses inode chunk indexes format by default.)

Link: https://lore.kernel.org/r/20210922095141.233938-1-hsiangkao@linux.alibaba.com
Fixes: c5aa903a59db ("erofs: support reading chunk-based uncompressed files")
Reviewed-by: Liu Bo <bo.liu@linux.alibaba.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

erofs: fix double free of 'copied'

Dan reported a new smatch warning [1]
"fs/erofs/inode.c:210 erofs_read_inode() error: double free of 'copied'"

Due to new chunk-based format handling logic, the error path can be
called after kfree(copied).

Set "copied = NULL" after kfree(copied) to fix this.

[1] https://lore.kernel.org/r/202108251030.bELQozR7-lkp@intel.com

Link: https://lore.kernel.org/r/20210825120757.11034-1-hsiangkao@linux.alibaba.com
Fixes: c5aa903a59db ("erofs: support reading chunk-based uncompressed files")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

erofs: support reading chunk-based uncompressed files

Add runtime support for chunk-based uncompressed files
described in the previous patch.

Link: https://lore.kernel.org/r/20210820100019.208490-2-hsiangkao@linux.alibaba.com
Reviewed-by: Liu Bo <bo.liu@linux.alibaba.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

erofs: add fiemap support with iomap

This adds fiemap support for both uncompressed files and compressed
files by using iomap infrastructure.

Link: https://lore.kernel.org/r/20210813052931.203280-3-hsiangkao@linux.alibaba.com
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

erofs: dax support for non-tailpacking regular file

DAX is quite useful for some VM use cases in order to save guest
memory extremely with minimal lightweight EROFS.

In order to prepare for such use cases, add preliminary dax support
for non-tailpacking regular files for now.

Tested with the DRAM-emulated PMEM and the EROFS image generated by
"mkfs.erofs -Enoinline_data enwik9.fsdax.img enwik9"

Link: https://lore.kernel.org/r/20210805003601.183063-3-hsiangkao@linux.alibaba.com
Cc: nvdimm@lists.linux.dev
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

erofs: iomap support for non-tailpacking DIO

Add iomap support for non-tailpacking uncompressed data in order to
support DIO and DAX.

Direct I/O is useful in certain scenarios for uncompressed files.
For example, double pagecache can be avoid by direct I/O when
loop device is used for uncompressed files containing upper layer
compressed filesystem.

This adds iomap DIO support for non-tailpacking cases first and
tail-packing inline files are handled in the follow-up patch.

Link: https://lore.kernel.org/r/20210805003601.183063-2-hsiangkao@linux.alibaba.com
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Huang Jianan <huangjianan@oppo.com>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

erofs: clean up file headers & footers

- Remove my outdated misleading email address;

- Get rid of all unnecessary trailing newline by accident.

Link: https://lore.kernel.org/r/20210602160634.10757-1-xiang@kernel.org
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

erofs: add unsupported inode i_format check

If any unknown i_format fields are set (may be of some new incompat
inode features), mark such inode as unsupported.

Just in case of any new incompat i_format fields added in the future.

Link: https://lore.kernel.org/r/20210329003614.6583-1-hsiangkao@aol.com
Fixes: 431339ba9042 ("staging: erofs: add inode operations")
Cc: <stable@vger.kernel.org> # 4.19+
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>

fs: make helpers idmap mount aware

Extend some inode methods with an additional user namespace argument. A
filesystem that is aware of idmapped mounts will receive the user
namespace the mount has been marked with. This can be used for
additional permission checking and also to enable filesystems to
translate between uids and gids if they need to. We have implemented all
relevant helpers in earlier patches.

As requested we simply extend the exisiting inode method instead of
introducing new ones. This is a little more code churn but it's mostly
mechanical and doesnt't leave us with additional inode methods.

Link: https://lore.kernel.org/r/20210121131959.646623-25-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

stat: handle idmapped mounts

The generic_fillattr() helper fills in the basic attributes associated
with an inode. Enable it to handle idmapped mounts. If the inode is
accessed through an idmapped mount map it into the mount's user
namespace before we store the uid and gid. If the initial user namespace
is passed nothing changes so non-idmapped mounts will see identical
behavior as before.

Link: https://lore.kernel.org/r/20210121131959.646623-12-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

erofs: derive atime instead of leaving it empty

EROFS has _only one_ ondisk timestamp (ctime is currently
documented and recorded, we might also record mtime instead
with a new compat feature if needed) for each extended inode
since EROFS isn't mainly for archival purposes so no need to
keep all timestamps on disk especially for Android scenarios
due to security concerns. Also, romfs/cramfs don't have their
own on-disk timestamp, and squashfs only records mtime instead.

Let's also derive access time from ondisk timestamp rather than
leaving it empty, and if mtime/atime for each file are really
needed for specific scenarios as well, we can also use xattrs
to record them then.

Link: https://lore.kernel.org/r/20201031195102.21221-1-hsiangkao@aol.com
[ Gao Xiang: It'd be better to backport for user-friendly concern. ]
Fixes: 431339ba9042 ("staging: erofs: add inode operations")
Cc: stable <stable@vger.kernel.org> # 4.19+
Reported-by: nl6720 <nl6720@gmail.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>

erofs: fix extended inode could cross boundary

Each ondisk inode should be aligned with inode slot boundary
(32-byte alignment) because of nid calculation formula, so all
compact inodes (32 byte) cannot across page boundary. However,
extended inode is now 64-byte form, which can across page boundary
in principle if the location is specified on purpose, although
it's hard to be generated by mkfs due to the allocation policy
and rarely used by Android use case now mainly for > 4GiB files.

For now, only two fields `i_ctime_nsec` and `i_nlink' couldn't
be read from disk properly and cause out-of-bound memory read
with random value.

Let's fix now.

Fixes: 431339ba9042 ("staging: erofs: add inode operations")
Cc: <stable@vger.kernel.org> # 4.19+
Link: https://lore.kernel.org/r/20200729175801.GA23973@xiangao.remote.csb
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>

erofs: Replace HTTP links with HTTPS ones

Rationale:
Reduces attack surface on kernel devs opening the links for MITM
as HTTPS traffic is much harder to manipulate.

Deterministic algorithm:
For each file:
If not .svg:
For each line:
If doesn't contain `\bxmlns\b`:
For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`:
If neither `\bgnu\.org/license`, nor `\bmozilla\.org/MPL\b`:
If both the HTTP and HTTPS versions
return 200 OK and serve the same content:
Replace HTTP with HTTPS.

Reviewed-by: Gao Xiang <hsiangkao@redhat.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de>
Link: https://lore.kernel.org/r/20200713130944.34419-1-grandmaster@al2klimov.de
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>

erofs: code cleanup by removing ifdef macro surrounding

Define erofs_listxattr and erofs_xattr_handlers to NULL when
CONFIG_EROFS_FS_XATTR is not enabled, then we can remove many
ugly ifdef macros in the code.

Signed-off-by: Chengguang Xu <cgxu519@mykernel.net>
Reviewed-by: Gao Xiang <hsiangkao@redhat.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Link: https://lore.kernel.org/r/20200526090343.22794-1-cgxu519@mykernel.net
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>

erofs: always use iget5_locked

As Christoph said [1] [2], "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. "

[1] https://lore.kernel.org/r/20190829102426.GE20598@infradead.org/
[2] https://lore.kernel.org/r/20190902125320.GA16726@infradead.org/
Reported-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
Link: https://lore.kernel.org/r/20190904020912.63925-25-gaoxiang25@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

erofs: rename errln/infoln/debugln to erofs_{err, info, dbg}

Add prefix "erofs_" to these functions and print
sb->s_id as a prefix to erofs_{err, info} so that
the user knows which file system is affected.

Reported-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
Link: https://lore.kernel.org/r/20190904020912.63925-23-gaoxiang25@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

erofs: save one level of indentation

As Christoph said [1], ".. and save one
level of indentation."

[1] https://lore.kernel.org/r/20190829102426.GE20598@infradead.org/
Reported-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
Link: https://lore.kernel.org/r/20190904020912.63925-22-gaoxiang25@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

erofs: kill all erofs specific fault injection

As Christoph suggested [1], "Please just use plain kmalloc
everywhere and let the normal kernel error injection code
take care of injeting any errors."

[1] https://lore.kernel.org/r/20190829102426.GE20598@infradead.org/
Reported-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
Link: https://lore.kernel.org/r/20190904020912.63925-20-gaoxiang25@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

erofs: add "erofs_" prefix for common and short functions

Add erofs_ prefix to free_inode, alloc_inode, ...

Reported-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
Link: https://lore.kernel.org/r/20190904020912.63925-19-gaoxiang25@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

erofs: kill prio and nofail of erofs_get_meta_page()

As Christoph pointed out [1],
"Why is there __erofs_get_meta_page with the two weird
booleans instead of a single erofs_get_meta_page that
gets and gfp_t for additional flags and an unsigned int
for additional bio op flags."

And since all callers can handle errors, let's kill
prio and nofail and erofs_get_inline_page() now.

[1] https://lore.kernel.org/r/20190830162812.GA10694@infradead.org/
Reported-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
Link: https://lore.kernel.org/r/20190904020912.63925-17-gaoxiang25@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

erofs: better erofs symlink stuffs

Fix as Christoph suggested [1] [2], "remove is_inode_fast_symlink
and just opencode it in the few places using it"

and
"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."

[1] https://lore.kernel.org/r/20190830163910.GB29603@infradead.org/
[2] https://lore.kernel.org/r/20190829102426.GE20598@infradead.org/
Reported-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
Link: https://lore.kernel.org/r/20190904020912.63925-13-gaoxiang25@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

erofs: update comments in inode.c

As Christoph suggested [1], update them all.

[1] https://lore.kernel.org/r/20190829102426.GE20598@infradead.org/
Reported-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
Link: https://lore.kernel.org/r/20190904020912.63925-12-gaoxiang25@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

erofs: use erofs_inode naming

As Christoph suggested [1], "Why is this called vnode instead
of inode? That seems like a rather odd naming for a Linux
file system."

[1] https://lore.kernel.org/r/20190829101545.GC20598@infradead.org/
Reported-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
Link: https://lore.kernel.org/r/20190904020912.63925-10-gaoxiang25@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

erofs: better naming for erofs inode related stuffs

updates inode naming
- kill is_inode_layout_compression [1]
- kill magic underscores [2] [3]
- better naming for datamode & data_mapping_mode [3]
- better naming erofs_inode_{compact, extended} [4]

[1] https://lore.kernel.org/r/20190829102426.GE20598@infradead.org/
[2] https://lore.kernel.org/r/20190829102426.GE20598@infradead.org/
[3] https://lore.kernel.org/r/20190902122627.GN15931@infradead.org/
[4] https://lore.kernel.org/r/20190902125438.GA17750@infradead.org/
Reported-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
Link: https://lore.kernel.org/r/20190904020912.63925-8-gaoxiang25@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

erofs: some macros are much more readable as a function

As Christoph suggested [1], these macros are much
more readable as a function.

[1] https://lore.kernel.org/r/20190829095954.GB20598@infradead.org/
Reported-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
Link: https://lore.kernel.org/r/20190904020912.63925-4-gaoxiang25@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

erofs: using switch-case while checking the inode type.

while filling the linux inode, using switch-case statement to check
the type of inode.
switch-case statement looks more clean here.

Signed-off-by: Pratik Shinde <pratikshinde320@gmail.com>
Reviewed-by: Gao Xiang <gaoxiang25@huawei.com>
Link: https://lore.kernel.org/r/20190830095615.10995-1-pratikshinde320@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

erofs: remove all likely/unlikely annotations

As Dan Carpenter suggested [1], I have to remove
all erofs likely/unlikely annotations.

[1] https://lore.kernel.org/linux-fsdevel/20190829154346.GK23584@kadam/
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
Link: https://lore.kernel.org/r/20190829163827.203274-1-gaoxiang25@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

erofs: move erofs out of staging

EROFS filesystem has been merged into linux-staging for a year.

EROFS is designed to be a better solution of saving extra storage
space with guaranteed end-to-end performance for read-only files
with the help of reduced metadata, fixed-sized output compression
and decompression inplace technologies.

In the past year, EROFS was greatly improved by many people as
a staging driver, self-tested, betaed by a large number of our
internal users, successfully applied to almost all in-service
HUAWEI smartphones as the part of EMUI 9.1 and proven to be stable
enough to be moved out of staging.

EROFS is a self-contained filesystem driver. Although there are
still some TODOs to be more generic, we have a dedicated team
actively keeping on working on EROFS in order to make it better
with the evolution of Linux kernel as the other in-kernel filesystems.

As Pavel suggested, it's better to do as one commit since git
can do moves and all histories will be saved in this way.

Let's promote it from staging and enhance it more actively as
a "real" part of kernel for more wider scenarios!

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Pavel Machek <pavel@denx.de>
Cc: David Sterba <dsterba@suse.cz>
Cc: Amir Goldstein <amir73il@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Darrick J . Wong <darrick.wong@oracle.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Richard Weinberger <richard@nod.at>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Chao Yu <yuchao0@huawei.com>
Cc: Miao Xie <miaoxie@huawei.com>
Cc: Li Guifu <bluce.liguifu@huawei.com>
Cc: Fang Wei <fangwei1@huawei.com>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
Link: https://lore.kernel.org/r/20190822213659.5501-1-hsiangkao@aol.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>