kernel/linux.git/fs/stat.c, branch v6.12.80

introduce fd_file(), convert all accessors to it.

2024-08-13T02:00:43+00:00

For any changes of struct fd representation we need to turn existing accesses to fields into calls of wrappers. Accesses to struct fd::flags are very few (3 in linux/file.h, 1 in net/socket.c, 3 in fs/overlayfs/file.c and 3 more in explicit initializers). Those can be dealt with in the commit converting to new layout; accesses to struct fd::file are too many for that. This commit converts (almost) all of f.file to fd_file(f). It's not entirely mechanical ('file' is used as a member name more than just in struct fd) and it does not even attempt to distinguish the uses in pointer context from those in boolean context; the latter will be eventually turned into a separate helper (fd_empty()). NOTE: mass conversion to fd_empty(), tempting as it might be, is a bad idea; better do that piecewise in commit that convert from fdget...() to CLASS(...). [conflicts in fs/fhandle.c, kernel/bpf/syscall.c, mm/memcontrol.c caught by git; fs/stat.c one got caught by git grep] [fs/xattr.c conflict] Reviewed-by: Christian Brauner Signed-off-by: Al Viro

Merge tag 'for-6.11/block-20240710' of git://git.kernel.dk/linux

2024-07-15T21:20:22+00:00

Pull block updates from Jens Axboe: - NVMe updates via Keith: - Device initialization memory leak fixes (Keith) - More constants defined (Weiwen) - Target debugfs support (Hannes) - PCIe subsystem reset enhancements (Keith) - Queue-depth multipath policy (Redhat and PureStorage) - Implement get_unique_id (Christoph) - Authentication error fixes (Gaosheng) - MD updates via Song - sync_action fix and refactoring (Yu Kuai) - Various small fixes (Christoph Hellwig, Li Nan, and Ofir Gal, Yu Kuai, Benjamin Marzinski, Christophe JAILLET, Yang Li) - Fix loop detach/open race (Gulam) - Fix lower control limit for blk-throttle (Yu) - Add module descriptions to various drivers (Jeff) - Add support for atomic writes for block devices, and statx reporting for same. Includes SCSI and NVMe (John, Prasad, Alan) - Add IO priority information to block trace points (Dongliang) - Various zone improvements and tweaks (Damien) - mq-deadline tag reservation improvements (Bart) - Ignore direct reclaim swap writes in writeback throttling (Baokun) - Block integrity improvements and fixes (Anuj) - Add basic support for rust based block drivers. Has a dummy null_blk variant for now (Andreas) - Series converting driver settings to queue limits, and cleanups and fixes related to that (Christoph) - Cleanup for poking too deeply into the bvec internals, in preparation for DMA mapping API changes (Christoph) - Various minor tweaks and fixes (Jiapeng, John, Kanchan, Mikulas, Ming, Zhu, Damien, Christophe, Chaitanya) * tag 'for-6.11/block-20240710' of git://git.kernel.dk/linux: (206 commits) floppy: add missing MODULE_DESCRIPTION() macro loop: add missing MODULE_DESCRIPTION() macro ublk_drv: add missing MODULE_DESCRIPTION() macro xen/blkback: add missing MODULE_DESCRIPTION() macro block/rnbd: Constify struct kobj_type block: take offset into account in blk_bvec_map_sg again block: fix get_max_segment_size() warning loop: Don't bother validating blocksize virtio_blk: Don't bother validating blocksize null_blk: Don't bother validating blocksize block: Validate logical block size in blk_validate_limits() virtio_blk: Fix default logical block size fallback nvmet-auth: fix nvmet_auth hash error handling nvme: implement ->get_unique_id block: pass a phys_addr_t to get_max_segment_size block: add a bvec_phys helper blk-lib: check for kill signal in ioctl BLKZEROOUT block: limit the Write Zeroes to manually writing zeroes fallback block: refacto blkdev_issue_zeroout block: move read-only and supported checks into (__)blkdev_issue_zeroout ...

vfs: support statx(..., NULL, AT_EMPTY_PATH, ...)

2024-06-27T16:31:20+00:00

The newly used helper also checks for empty ("") paths. NULL paths with any flag value other than AT_EMPTY_PATH go the usual route and end up with -EFAULT to retain compatibility (Rust is abusing calls of the sort to detect availability of statx). This avoids path lookup code, lockref management, memory allocation and in case of NULL path userspace memory access (which can be quite expensive with SMAP on x86_64). Benchmarked with statx(..., AT_EMPTY_PATH, ...) running on Sapphire Rapids, with the "" path for the first two cases and NULL for the last one. Results in ops/s: stock: 4231237 pre-check: 5944063 (+40%) NULL path: 6601619 (+11%/+56%) Signed-off-by: Mateusz Guzik Link: https://lore.kernel.org/r/20240625151807.620812-1-mjguzik@gmail.com Tested-by: Xi Ruoyao [brauner: use path_mounted() and other tweaks] Signed-off-by: Christian Brauner

stat: use vfs_empty_path() helper

2024-06-27T16:31:20+00:00

Use the newly added helper for this. Signed-off-by: Christian Brauner

block: Add atomic write support for statx

2024-06-20T21:19:17+00:00

Extend statx system call to return additional info for atomic write support support if the specified file is a block device. Reviewed-by: Martin K. Petersen Signed-off-by: Prasad Singamsetty Signed-off-by: John Garry Reviewed-by: Keith Busch Acked-by: Darrick J. Wong Reviewed-by: Darrick J. Wong Reviewed-by: Luis Chamberlain Link: https://lore.kernel.org/r/20240620125359.2684798-7-john.g.garry@oracle.com Signed-off-by: Jens Axboe

fs: Add initial atomic write support info to statx

2024-06-20T21:19:17+00:00

Extend statx system call to return additional info for atomic write support support for a file. Helper function generic_fill_statx_atomic_writes() can be used by FSes to fill in the relevant statx fields. For now atomic_write_segments_max will always be 1, otherwise some rules would need to be imposed on iovec length and alignment, which we don't want now. Signed-off-by: Prasad Singamsetty jpg: relocate bdev support to another patch Reviewed-by: Darrick J. Wong Reviewed-by: Martin K. Petersen Signed-off-by: John Garry Acked-by: Darrick J. Wong Link: https://lore.kernel.org/r/20240620125359.2684798-5-john.g.garry@oracle.com Signed-off-by: Jens Axboe

vfs: retire user_path_at_empty and drop empty arg from getname_flags

2024-06-05T15:03:57+00:00

No users after do_readlinkat started doing the job on its own. Signed-off-by: Mateusz Guzik Link: https://lore.kernel.org/r/20240604155257.109500-3-mjguzik@gmail.com Reviewed-by: Jan Kara Signed-off-by: Christian Brauner

vfs: stop using user_path_at_empty in do_readlinkat

2024-06-05T15:03:56+00:00

It is the only consumer and it saddles getname_flags with an argument set to NULL by everyone else. Instead the routine can do the empty check on its own. Then user_path_at_empty can get retired and getname_flags can lose the argument. Signed-off-by: Mateusz Guzik Link: https://lore.kernel.org/r/20240604155257.109500-2-mjguzik@gmail.com Reviewed-by: Jan Kara Signed-off-by: Christian Brauner

statx: stx_subvol

2024-03-26T08:01:18+00:00

Add a new statx field for (sub)volume identifiers, as implemented by btrfs and bcachefs. This includes bcachefs support; we'll definitely want btrfs support as well. Link: https://lore.kernel.org/linux-fsdevel/2uvhm6gweyl7iyyp2xpfryvcu2g3padagaeqcbiavjyiis6prl@yjm725bizncq/ Signed-off-by: Kent Overstreet Cc: Josef Bacik Cc: Miklos Szeredi Cc: Christian Brauner Cc: David Howells Signed-off-by: Kent Overstreet Link: https://lore.kernel.org/r/20240308022914.196982-1-kent.overstreet@linux.dev Signed-off-by: Johannes Thumshirn Signed-off-by: Christian Brauner

Merge tag 'vfs-6.8.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2024-01-08T18:57:34+00:00

Pull vfs mount updates from Christian Brauner: "This contains the work to retrieve detailed information about mounts via two new system calls. This is hopefully the beginning of the end of the saga that started with fsinfo() years ago. The LWN articles in [1] and [2] can serve as a summary so we can avoid rehashing everything here. At LSFMM in May 2022 we got into a room and agreed on what we want to do about fsinfo(). Basically, split it into pieces. This is the first part of that agreement. Specifically, it is concerned with retrieving information about mounts. So this only concerns the mount information retrieval, not the mount table change notification, or the extended filesystem specific mount option work. That is separate work. Currently mounts have a 32bit id. Mount ids are already in heavy use by libmount and other low-level userspace but they can't be relied upon because they're recycled very quickly. We agreed that mounts should carry a unique 64bit id by which they can be referenced directly. This is now implemented as part of this work. The new 64bit mount id is exposed in statx() through the new STATX_MNT_ID_UNIQUE flag. If the flag isn't raised the old mount id is returned. If it is raised and the kernel supports the new 64bit mount id the flag is raised in the result mask and the new 64bit mount id is returned. New and old mount ids do not overlap so they cannot be conflated. Two new system calls are introduced that operate on the 64bit mount id: statmount() and listmount(). A summary of the api and usage can be found on LWN as well (cf. [3]) but of course, I'll provide a summary here as well. Both system calls rely on struct mnt_id_req. Which is the request struct used to pass the 64bit mount id identifying the mount to operate on. It is extensible to allow for the addition of new parameters and for future use in other apis that make use of mount ids. statmount() mimicks the semantics of statx() and exposes a set flags that userspace may raise in mnt_id_req to request specific information to be retrieved. A statmount() call returns a struct statmount filled in with information about the requested mount. Supported requests are indicated by raising the request flag passed in struct mnt_id_req in the @mask argument in struct statmount. Currently we do support: - STATMOUNT_SB_BASIC: Basic filesystem info - STATMOUNT_MNT_BASIC Mount information (mount id, parent mount id, mount attributes etc) - STATMOUNT_PROPAGATE_FROM Propagation from what mount in current namespace - STATMOUNT_MNT_ROOT Path of the root of the mount (e.g., mount --bind /bla /mnt returns /bla) - STATMOUNT_MNT_POINT Path of the mount point (e.g., mount --bind /bla /mnt returns /mnt) - STATMOUNT_FS_TYPE Name of the filesystem type as the magic number isn't enough due to submounts The string options STATMOUNT_MNT_{ROOT,POINT} and STATMOUNT_FS_TYPE are appended to the end of the struct. Userspace can use the offsets in @fs_type, @mnt_root, and @mnt_point to reference those strings easily. The struct statmount reserves quite a bit of space currently for future extensibility. This isn't really a problem and if this bothers us we can just send a follow-up pull request during this cycle. listmount() is given a 64bit mount id via mnt_id_req just as statmount(). It takes a buffer and a size to return an array of the 64bit ids of the child mounts of the requested mount. Userspace can thus choose to either retrieve child mounts for a mount in batches or iterate through the child mounts. For most use-cases it will be sufficient to just leave space for a few child mounts. But for big mount tables having an iterator is really helpful. Iterating through a mount table works by setting @param in mnt_id_req to the mount id of the last child mount retrieved in the previous listmount() call" Link: https://lwn.net/Articles/934469 [1] Link: https://lwn.net/Articles/829212 [2] Link: https://lwn.net/Articles/950569 [3] * tag 'vfs-6.8.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: add selftest for statmount/listmount fs: keep struct mnt_id_req extensible wire up syscalls for statmount/listmount add listmount(2) syscall statmount: simplify string option retrieval statmount: simplify numeric option retrieval add statmount(2) syscall namespace: extract show_path() helper mounts: keep list of mounts in an rbtree add unique mount ID