kernel/git/next/linux-next.git/fs/erofs/super.c, branch akpm

dax: introduce holder for dax_device

2022-06-27T20:45:19+00:00

Patch series "v14 fsdax-rmap + v11 fsdax-reflink", v2. The patchset fsdax-rmap is aimed to support shared pages tracking for fsdax. It moves owner tracking from dax_assocaite_entry() to pmem device driver, by introducing an interface ->memory_failure() for struct pagemap. This interface is called by memory_failure() in mm, and implemented by pmem device. Then call holder operations to find the filesystem which the corrupted data located in, and call filesystem handler to track files or metadata associated with this page. Finally we are able to try to fix the corrupted data in filesystem and do other necessary processing, such as killing processes who are using the files affected. The call trace is like this: memory_failure() |* fsdax case |------------ |pgmap->ops->memory_failure() => pmem_pgmap_memory_failure() | dax_holder_notify_failure() => | dax_device->holder_ops->notify_failure() => | - xfs_dax_notify_failure() | |* xfs_dax_notify_failure() | |-------------------------- | | xfs_rmap_query_range() | | xfs_dax_failure_fn() | | * corrupted on metadata | | try to recover data, call xfs_force_shutdown() | | * corrupted on file data | | try to recover data, call mf_dax_kill_procs() |* normal case |------------- |mf_generic_kill_procs() The patchset fsdax-reflink attempts to add CoW support for fsdax, and takes XFS, which has both reflink and fsdax features, as an example. One of the key mechanisms needed to be implemented in fsdax is CoW. Copy the data from srcmap before we actually write data to the destination iomap. And we just copy range in which data won't be changed. Another mechanism is range comparison. In page cache case, readpage() is used to load data on disk to page cache in order to be able to compare data. In fsdax case, readpage() does not work. So, we need another compare data with direct access support. With the two mechanisms implemented in fsdax, we are able to make reflink and fsdax work together in XFS. This patch (of 14): To easily track filesystem from a pmem device, we introduce a holder for dax_device structure, and also its operation. This holder is used to remember who is using this dax_device: - When it is the backend of a filesystem, the holder will be the instance of this filesystem. - When this pmem device is one of the targets in a mapped device, the holder will be this mapped device. In this case, the mapped device has its own dax_device and it will follow the first rule. So that we can finally track to the filesystem we needed. The holder and holder_ops will be set when filesystem is being mounted, or an target device is being activated. Link: https://lkml.kernel.org/r/20220603053738.1218681-1-ruansy.fnst@fujitsu.com Link: https://lkml.kernel.org/r/20220603053738.1218681-2-ruansy.fnst@fujitsu.com Signed-off-by: Shiyang Ruan Reviewed-by: Christoph Hellwig Reviewed-by: Dan Williams Reviewed-by: Darrick J. Wong Cc: Dave Chinner Cc: Jane Chu Cc: Goldwyn Rodrigues Cc: Al Viro Cc: Matthew Wilcox Cc: Naoya Horiguchi Cc: Miaohe Lin Cc: Dan Williams Cc: Goldwyn Rodrigues Cc: Ritesh Harjani Signed-off-by: Andrew Morton

Merge tag 'folio-5.19' of git://git.infradead.org/users/willy/pagecache

2022-05-25T02:55:07+00:00

Pull page cache updates from Matthew Wilcox: - Appoint myself page cache maintainer - Fix how scsicam uses the page cache - Use the memalloc_nofs_save() API to replace AOP_FLAG_NOFS - Remove the AOP flags entirely - Remove pagecache_write_begin() and pagecache_write_end() - Documentation updates - Convert several address_space operations to use folios: - is_dirty_writeback - readpage becomes read_folio - releasepage becomes release_folio - freepage becomes free_folio - Change filler_t to require a struct file pointer be the first argument like ->read_folio * tag 'folio-5.19' of git://git.infradead.org/users/willy/pagecache: (107 commits) nilfs2: Fix some kernel-doc comments Appoint myself page cache maintainer fs: Remove aops->freepage secretmem: Convert to free_folio nfs: Convert to free_folio orangefs: Convert to free_folio fs: Add free_folio address space operation fs: Convert drop_buffers() to use a folio fs: Change try_to_free_buffers() to take a folio jbd2: Convert release_buffer_page() to use a folio jbd2: Convert jbd2_journal_try_to_free_buffers to take a folio reiserfs: Convert release_buffer_page() to use a folio fs: Remove last vestiges of releasepage ubifs: Convert to release_folio reiserfs: Convert to release_folio orangefs: Convert to release_folio ocfs2: Convert to release_folio nilfs2: Remove comment about releasepage nfs: Convert to release_folio jfs: Convert to release_folio ...

erofs: scan devices from device table

2022-05-17T16:11:21+00:00

When "-o device" mount option is not specified, scan the device table and instantiate the devices if there's any in the device table. In this case, the tag field of each device slot uniquely specifies a device. Signed-off-by: Jeffle Xu Reviewed-by: Gao Xiang Link: https://lore.kernel.org/r/20220512055601.106109-1-jefflexu@linux.alibaba.com Signed-off-by: Gao Xiang

erofs: add 'fsid' mount option

2022-05-17T16:11:21+00:00

Introduce 'fsid' mount option to enable on-demand read sementics, in which case, erofs will be mounted from data blobs. Users could specify the name of primary data blob by this mount option. Signed-off-by: Jeffle Xu Reviewed-by: Gao Xiang Link: https://lore.kernel.org/r/20220425122143.56815-22-jefflexu@linux.alibaba.com Acked-by: Chao Yu Tested-by: Zichen Tian Tested-by: Jia Zhu Tested-by: Yan Song Signed-off-by: Gao Xiang

erofs: implement fscache-based data readahead

2022-05-17T16:11:21+00:00

Implement fscache-based data readahead. Also registers an individual bdi for each erofs instance to enable readahead. Signed-off-by: Jeffle Xu Reviewed-by: Gao Xiang Link: https://lore.kernel.org/r/20220425122143.56815-21-jefflexu@linux.alibaba.com Acked-by: Chao Yu Signed-off-by: Gao Xiang

erofs: register fscache context for extra data blobs

2022-05-17T16:11:20+00:00

Similar to the multi-device mode, erofs could be mounted from one primary data blob (mandatory) and multiple extra data blobs (optional). Register fscache context for each extra data blob. Signed-off-by: Jeffle Xu Reviewed-by: Gao Xiang Link: https://lore.kernel.org/r/20220425122143.56815-17-jefflexu@linux.alibaba.com Acked-by: Chao Yu Signed-off-by: Gao Xiang

erofs: register fscache context for primary data blob

2022-05-17T16:11:20+00:00

Registers fscache context for primary data blob. Also move the initialization of s_op and related fields forward, since anonymous inode will be allocated under the super block when registering the fscache context. Something worth mentioning about the cleanup routine. 1. The fscache context will instantiate anonymous inodes under the super block. Release these anonymous inodes when .put_super() is called, or we'll get "VFS: Busy inodes after unmount." warning. 2. The fscache context is initialized prior to the root inode. If .kill_sb() is called when mount failed, .put_super() won't be called when root inode has not been initialized yet. Thus .kill_sb() shall also contain the cleanup routine. Signed-off-by: Jeffle Xu Reviewed-by: Gao Xiang Link: https://lore.kernel.org/r/20220425122143.56815-16-jefflexu@linux.alibaba.com Acked-by: Chao Yu Signed-off-by: Gao Xiang

erofs: register fscache volume

2022-05-17T16:11:19+00:00

A new fscache based mode is going to be introduced for erofs, in which case on-demand read semantics is implemented through fscache. As the first step, register fscache volume for each erofs filesystem. That means, data blobs can not be shared among erofs filesystems. In the following iteration, we are going to introduce the domain semantics, in which case several erofs filesystems can belong to one domain, and data blobs can be shared among these erofs filesystems of one domain. Signed-off-by: Jeffle Xu Reviewed-by: Gao Xiang Link: https://lore.kernel.org/r/20220425122143.56815-12-jefflexu@linux.alibaba.com Acked-by: Chao Yu Signed-off-by: Gao Xiang

erofs: add fscache mode check helper

2022-05-17T16:11:19+00:00

Until then erofs is exactly blockdev based filesystem. A new fscache-based mode is going to be introduced for erofs to support scenarios where on-demand read semantics is needed, e.g. container image distribution. In this case, erofs could be mounted from data blobs through fscache. Add a helper checking which mode erofs works in, and twist the code in preparation for the upcoming fscache mode. Signed-off-by: Jeffle Xu Reviewed-by: Gao Xiang Link: https://lore.kernel.org/r/20220425122143.56815-11-jefflexu@linux.alibaba.com Acked-by: Chao Yu Signed-off-by: Gao Xiang

erofs: support idmapped mounts

2022-05-17T15:56:20+00:00

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) Reviewed-by: Gao Xiang Signed-off-by: Chao Yu Link: https://lore.kernel.org/r/20220517104103.3570721-1-chao@kernel.org Signed-off-by: Gao Xiang