kernel/linux.git/fs/stat.c, branch v6.1.168

vfs: support STATX_DIOALIGN on block devices

2022-09-12T00:47:12+00:00

Add support for STATX_DIOALIGN to block devices, so that direct I/O alignment restrictions are exposed to userspace in a generic way. Note that this breaks the tradition of stat operating only on the block device node, not the block device itself. However, it was felt that doing this is preferable, in order to make the interface useful and avoid needing separate interfaces for regular files and block devices. Signed-off-by: Eric Biggers Reviewed-by: Christoph Hellwig Reviewed-by: Christian Brauner (Microsoft) Link: https://lore.kernel.org/r/20220827065851.135710-3-ebiggers@kernel.org

statx: add direct I/O alignment information

2022-09-12T00:47:04+00:00

Traditionally, the conditions for when DIO (direct I/O) is supported were fairly simple. For both block devices and regular files, DIO had to be aligned to the logical block size of the block device. However, due to filesystem features that have been added over time (e.g. multi-device support, data journalling, inline data, encryption, verity, compression, checkpoint disabling, log-structured mode), the conditions for when DIO is allowed on a regular file have gotten increasingly complex. Whether a particular regular file supports DIO, and with what alignment, can depend on various file attributes and filesystem mount options, as well as which block device(s) the file's data is located on. Moreover, the general rule of DIO needing to be aligned to the block device's logical block size was recently relaxed to allow user buffers (but not file offsets) aligned to the DMA alignment instead. See commit bf8d08532bc1 ("iomap: add support for dma aligned direct-io"). XFS has an ioctl XFS_IOC_DIOINFO that exposes DIO alignment information. Uplifting this to the VFS is one possibility. However, as discussed (https://lore.kernel.org/linux-fsdevel/20220120071215.123274-1-ebiggers@kernel.org/T/#u), this ioctl is rarely used and not known to be used outside of XFS-specific code. It was also never intended to indicate when a file doesn't support DIO at all, nor was it intended for block devices. Therefore, let's expose this information via statx(). Add the STATX_DIOALIGN flag and two new statx fields associated with it: * stx_dio_mem_align: the alignment (in bytes) required for user memory buffers for DIO, or 0 if DIO is not supported on the file. * stx_dio_offset_align: the alignment (in bytes) required for file offsets and I/O segment lengths for DIO, or 0 if DIO is not supported on the file. This will only be nonzero if stx_dio_mem_align is nonzero, and vice versa. Note that as with other statx() extensions, if STATX_DIOALIGN isn't set in the returned statx struct, then these new fields won't be filled in. This will happen if the file is neither a regular file nor a block device, or if the file is a regular file and the filesystem doesn't support STATX_DIOALIGN. It might also happen if the caller didn't include STATX_DIOALIGN in the request mask, since statx() isn't required to return unrequested information. This commit only adds the VFS-level plumbing for STATX_DIOALIGN. For regular files, individual filesystems will still need to add code to support it. For block devices, a separate commit will wire it up too. Reviewed-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Reviewed-by: Martin K. Petersen Reviewed-by: Christian Brauner (Microsoft) Signed-off-by: Eric Biggers Link: https://lore.kernel.org/r/20220827065851.135710-2-ebiggers@kernel.org

Merge tag 'riscv-for-linus-5.19-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

2022-05-31T21:10:54+00:00

Pull RISC-V updates from Palmer Dabbelt: - Support for the Svpbmt extension, which allows memory attributes to be encoded in pages - Support for the Allwinner D1's implementation of page-based memory attributes - Support for running rv32 binaries on rv64 systems, via the compat subsystem - Support for kexec_file() - Support for the new generic ticket-based spinlocks, which allows us to also move to qrwlock. These should have already gone in through the asm-geneic tree as well - A handful of cleanups and fixes, include some larger ones around atomics and XIP * tag 'riscv-for-linus-5.19-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (51 commits) RISC-V: Prepare dropping week attribute from arch_kexec_apply_relocations[_add] riscv: compat: Using seperated vdso_maps for compat_vdso_info RISC-V: Fix the XIP build RISC-V: Split out the XIP fixups into their own file RISC-V: ignore xipImage RISC-V: Avoid empty create_*_mapping definitions riscv: Don't output a bogus mmu-type on a no MMU kernel riscv: atomic: Add custom conditional atomic operation implementation riscv: atomic: Optimize dec_if_positive functions riscv: atomic: Cleanup unnecessary definition RISC-V: Load purgatory in kexec_file RISC-V: Add purgatory RISC-V: Support for kexec_file on panic RISC-V: Add kexec_file support RISC-V: use memcpy for kexec_file mode kexec_file: Fix kexec_file.c build error for riscv platform riscv: compat: Add COMPAT Kbuild skeletal support riscv: compat: ptrace: Add compat_arch_ptrace implement riscv: compat: signal: Add rt_frame implementation riscv: add memory-type errata for T-Head ...

fs: stat: compat: Add __ARCH_WANT_COMPAT_STAT

2022-04-26T20:35:45+00:00

RISC-V doesn't neeed compat_stat, so using __ARCH_WANT_COMPAT_STAT to exclude unnecessary SYSCALL functions. Signed-off-by: Guo Ren Signed-off-by: Guo Ren Reviewed-by: Arnd Bergmann Reviewed-by: Christoph Hellwig Tested-by: Heiko Stuebner Acked-by: Helge Deller # parisc Link: https://lore.kernel.org/r/20220405071314.3225832-6-guoren@kernel.org Signed-off-by: Palmer Dabbelt

stat: fix inconsistency between struct stat and struct compat_stat

2022-04-12T23:35:08+00:00

struct stat (defined in arch/x86/include/uapi/asm/stat.h) has 32-bit st_dev and st_rdev; struct compat_stat (defined in arch/x86/include/asm/compat.h) has 16-bit st_dev and st_rdev followed by a 16-bit padding. This patch fixes struct compat_stat to match struct stat. [ Historical note: the old x86 'struct stat' did have that 16-bit field that the compat layer had kept around, but it was changes back in 2003 by "struct stat - support larger dev_t": https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git/commit/?id=e95b2065677fe32512a597a79db94b77b90c968d and back in those days, the x86_64 port was still new, and separate from the i386 code, and had already picked up the old version with a 16-bit st_dev field ] Note that we can't change compat_dev_t because it is used by compat_loop_info. Also, if the st_dev and st_rdev values are 32-bit, we don't have to use old_valid_dev to test if the value fits into them. This fixes -EOVERFLOW on filesystems that are on NVMe because NVMe uses the major number 259. Signed-off-by: Mikulas Patocka Cc: Andreas Schwab Cc: Matthew Wilcox Cc: Christoph Hellwig Signed-off-by: Linus Torvalds

io-uring: Make statx API stable

2022-03-10T16:33:55+00:00

One of the key architectual tenets is to keep the parameters for io-uring stable. After the call has been submitted, its value can be changed. Unfortunaltely this is not the case for the current statx implementation. IO-Uring change: This changes replaces the const char * filename pointer in the io_statx structure with a struct filename *. In addition it also creates the filename object during the prepare phase. With this change, the opcode also needs to invoke cleanup, so the filename object gets freed after processing the request. fs change: This replaces the const char* __user filename parameter in the two functions do_statx and vfs_statx with a struct filename *. In addition to be able to correctly construct a filename object a new helper function getname_statx_lookup_flags is introduced. The function makes sure that do_statx and vfs_statx is invoked with the correct lookup flags. Signed-off-by: Stefan Roesch Link: https://lore.kernel.org/r/20220225185326.1373304-2-shr@fb.com Signed-off-by: Jens Axboe

fs: add generic helper for filling statx attribute flags

2021-08-17T09:47:43+00:00

The immutable and append-only properties on an inode are published on the inode's i_flags and enforced by the VFS. Create a helper to fill the corresponding STATX_ATTR_ flags in the kstat structure from the inode's i_flags. Only orange was converted to use this helper. Other filesystems could use it in the future. Suggested-by: Miklos Szeredi Signed-off-by: Amir Goldstein Signed-off-by: Miklos Szeredi

fs: fix reporting supported extra file attributes for statx()

2021-04-18T03:03:50+00:00

statx(2) notes that any attribute that is not indicated as supported by stx_attributes_mask has no usable value. Commits 801e523796004 ("fs: move generic stat response attr handling to vfs_getattr_nosec") and 712b2698e4c02 ("fs/stat: Define DAX statx attribute") sets STATX_ATTR_AUTOMOUNT and STATX_ATTR_DAX, respectively, without setting stx_attributes_mask, which can cause xfstests generic/532 to fail. Fix this in the same way as commit 1b9598c8fb99 ("xfs: fix reporting supported extra file attributes for statx()") Fixes: 801e523796004 ("fs: move generic stat response attr handling to vfs_getattr_nosec") Fixes: 712b2698e4c02 ("fs/stat: Define DAX statx attribute") Cc: stable@kernel.org Signed-off-by: Theodore Ts'o

fs: make helpers idmap mount aware

2021-01-24T13:27:20+00:00

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 Cc: David Howells Cc: Al Viro Cc: linux-fsdevel@vger.kernel.org Reviewed-by: Christoph Hellwig Signed-off-by: Christian Brauner

stat: handle idmapped mounts

2021-01-24T13:27:17+00:00

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 Cc: David Howells Cc: Al Viro Cc: linux-fsdevel@vger.kernel.org Reviewed-by: Christoph Hellwig Reviewed-by: James Morris Signed-off-by: Christian Brauner