274c0e74e5
In this round, we've mainly focused on performance tuning and critical bug fixes occurred in low-end devices. Sheng Yong introduced lost_found feature to keep missing files during recovery instead of thrashing them. We're preparing coming fsverity implementation. And, we've got more features to communicate with users for better performance. In low-end devices, some memory-related issues were fixed, and subtle race condtions and corner cases were addressed as well. Enhancement: - large nat bitmaps for more free node ids - add three block allocation policies to pass down write hints given by user - expose extension list to user and introduce hot file extension - tune small devices seamlessly for low-end devices - set readdir_ra by default - give more resources under gc_urgent mode regarding to discard and cleaning - introduce fsync_mode to enforce posix or not - nowait aio support - add lost_found feature to keep dangling inodes - reserve bits for future fsverity feature - add test_dummy_encryption for FBE Bug fix: - don't use highmem for dentry pages - align memory boundary for bitops - truncate preallocated blocks in write errors - guarantee i_times on fsync call - clear CP_TRIMMED_FLAG correctly - prevent node chain loop during recovery - avoid data race between atomic write and background cleaning - avoid unnecessary selinux violation warnings on resgid option - GFP_NOFS to avoid deadlock in quota and read paths - fix f2fs_skip_inode_update to allow i_size recovery In addition to them, there are several minor bug fixes and clean-ups. -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEE00UqedjCtOrGVvQiQBSofoJIUNIFAlrFmaYACgkQQBSofoJI UNKaSw//RZraDQmODfDieyjGAd8y1NgGDju1jgk62QJUqe/G3jIKN/A39HU3I2Ak jLIotwZ8j1yNBUGbXMXZTY+6sRkQGJrcgawgvZ0gwWSeqTAiCi+AbqnNysTv8pDp Rh1iMCGvNKv1/vbFizJumcK2haH/KzX9Z7uDBjji4N7tTT1nUGVz+vmUO/qS6Xi0 44BrEN1rhaF71JNaiQE0WuEc0GY2IU0W7l4IWirJeNqsK0BTVPnq1vxc8SsQQRmn Wdr4rUw2SRAynGMCQZlMW/sG0sxV0WMAE0xVE8WCFMXzHx2GNVakUgXMTZ2DgUKT JlgdsB5NQYrZJqSEAdNq3WclJpznlhOLHp8hjITxSRxhd2j7GH7xujUoGSsNiXDr n2s3Xg6wWMx+D4vsfXYJuZQKYqZUcBlPRgXa74/aXnsxRTLaormJtFNWkLqELIzR Qaw7XIhZoOyKkH7CPSWk0eYyQVi13l9QV70iyBfY4bcN2aLZLxTX2Axwws3ESOCt Nf0jIe3L4k7MSdoMR0K51rhCMlPWDuddnQSs9Vsw3w8U5pVph+BKG5RBUI9N4hPv U0gKJfj8LIaxhHTfborEHf+hjq/0sN0TBPFBsAtqvv1LBXkMeWEeo0wXtxSJC89b 3xBRQ0p4Nox4fEHs36AZID2OMOV8iamiEqzP/o9ja0sMzEjnYmo= =Ligi -----END PGP SIGNATURE----- Merge tag 'f2fs-for-4.17' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs Pull f2fs update from Jaegeuk Kim: "In this round, we've mainly focused on performance tuning and critical bug fixes occurred in low-end devices. Sheng Yong introduced lost_found feature to keep missing files during recovery instead of thrashing them. We're preparing coming fsverity implementation. And, we've got more features to communicate with users for better performance. In low-end devices, some memory-related issues were fixed, and subtle race condtions and corner cases were addressed as well. Enhancements: - large nat bitmaps for more free node ids - add three block allocation policies to pass down write hints given by user - expose extension list to user and introduce hot file extension - tune small devices seamlessly for low-end devices - set readdir_ra by default - give more resources under gc_urgent mode regarding to discard and cleaning - introduce fsync_mode to enforce posix or not - nowait aio support - add lost_found feature to keep dangling inodes - reserve bits for future fsverity feature - add test_dummy_encryption for FBE Bug fixes: - don't use highmem for dentry pages - align memory boundary for bitops - truncate preallocated blocks in write errors - guarantee i_times on fsync call - clear CP_TRIMMED_FLAG correctly - prevent node chain loop during recovery - avoid data race between atomic write and background cleaning - avoid unnecessary selinux violation warnings on resgid option - GFP_NOFS to avoid deadlock in quota and read paths - fix f2fs_skip_inode_update to allow i_size recovery In addition to the above, there are several minor bug fixes and clean-ups" * tag 'f2fs-for-4.17' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (50 commits) f2fs: remain written times to update inode during fsync f2fs: make assignment of t->dentry_bitmap more readable f2fs: truncate preallocated blocks in error case f2fs: fix a wrong condition in f2fs_skip_inode_update f2fs: reserve bits for fs-verity f2fs: Add a segment type check in inplace write f2fs: no need to initialize zero value for GFP_F2FS_ZERO f2fs: don't track new nat entry in nat set f2fs: clean up with F2FS_BLK_ALIGN f2fs: check blkaddr more accuratly before issue a bio f2fs: Set GF_NOFS in read_cache_page_gfp while doing f2fs_quota_read f2fs: introduce a new mount option test_dummy_encryption f2fs: introduce F2FS_FEATURE_LOST_FOUND feature f2fs: release locks before return in f2fs_ioc_gc_range() f2fs: align memory boundary for bitops f2fs: remove unneeded set_cold_node() f2fs: add nowait aio support f2fs: wrap all options with f2fs_sb_info.mount_opt f2fs: Don't overwrite all types of node to keep node chain f2fs: introduce mount option for fsync mode ... |
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This directory attempts to document the ABI between the Linux kernel and userspace, and the relative stability of these interfaces. Due to the everchanging nature of Linux, and the differing maturity levels, these interfaces should be used by userspace programs in different ways. We have four different levels of ABI stability, as shown by the four different subdirectories in this location. Interfaces may change levels of stability according to the rules described below. The different levels of stability are: stable/ This directory documents the interfaces that the developer has defined to be stable. Userspace programs are free to use these interfaces with no restrictions, and backward compatibility for them will be guaranteed for at least 2 years. Most interfaces (like syscalls) are expected to never change and always be available. testing/ This directory documents interfaces that are felt to be stable, as the main development of this interface has been completed. The interface can be changed to add new features, but the current interface will not break by doing this, unless grave errors or security problems are found in them. Userspace programs can start to rely on these interfaces, but they must be aware of changes that can occur before these interfaces move to be marked stable. Programs that use these interfaces are strongly encouraged to add their name to the description of these interfaces, so that the kernel developers can easily notify them if any changes occur (see the description of the layout of the files below for details on how to do this.) obsolete/ This directory documents interfaces that are still remaining in the kernel, but are marked to be removed at some later point in time. The description of the interface will document the reason why it is obsolete and when it can be expected to be removed. removed/ This directory contains a list of the old interfaces that have been removed from the kernel. Every file in these directories will contain the following information: What: Short description of the interface Date: Date created KernelVersion: Kernel version this feature first showed up in. Contact: Primary contact for this interface (may be a mailing list) Description: Long description of the interface and how to use it. Users: All users of this interface who wish to be notified when it changes. This is very important for interfaces in the "testing" stage, so that kernel developers can work with userspace developers to ensure that things do not break in ways that are unacceptable. It is also important to get feedback for these interfaces to make sure they are working in a proper way and do not need to be changed further. How things move between levels: Interfaces in stable may move to obsolete, as long as the proper notification is given. Interfaces may be removed from obsolete and the kernel as long as the documented amount of time has gone by. Interfaces in the testing state can move to the stable state when the developers feel they are finished. They cannot be removed from the kernel tree without going through the obsolete state first. It's up to the developer to place their interfaces in the category they wish for it to start out in. Notable bits of non-ABI, which should not under any circumstances be considered stable: - Kconfig. Userspace should not rely on the presence or absence of any particular Kconfig symbol, in /proc/config.gz, in the copy of .config commonly installed to /boot, or in any invocation of the kernel build process. - Kernel-internal symbols. Do not rely on the presence, absence, location, or type of any kernel symbol, either in System.map files or the kernel binary itself. See Documentation/process/stable-api-nonsense.rst.