user/sven/linux.git/include/uapi/linux/fs.h, branch v6.9.5

Merge tag 'vfs-6.9.uuid' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2024-03-11T18:02:06Z

Pull vfs uuid updates from Christian Brauner: "This adds two new ioctl()s for getting the filesystem uuid and retrieving the sysfs path based on the path of a mounted filesystem. Getting the filesystem uuid has been implemented in filesystem specific code for a while it's now lifted as a generic ioctl" * tag 'vfs-6.9.uuid' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: xfs: add support for FS_IOC_GETFSSYSFSPATH fs: add FS_IOC_GETFSSYSFSPATH fat: Hook up sb->s_uuid fs: FS_IOC_GETUUID ovl: convert to super_set_uuid() fs: super_set_uuid()

fs: add FS_IOC_GETFSSYSFSPATH

2024-02-12T12:13:59Z

Add a new ioctl for getting the sysfs name of a filesystem - the path under /sys/fs. This is going to let us standardize exporting data from sysfs across filesystems, e.g. time stats. The returned path will always be of the form "$FSTYP/$SYSFS_IDENTIFIER", where the sysfs identifier may be a UUID (for bcachefs) or a device name (xfs). Cc: Christian Brauner Cc: Jan Kara Cc: Dave Chinner Cc: Darrick J. Wong Cc: Theodore Ts'o Cc: Josef Bacik Signed-off-by: Kent Overstreet Link: https://lore.kernel.org/r/20240207025624.1019754-6-kent.overstreet@linux.dev Signed-off-by: Christian Brauner

fs: FS_IOC_GETUUID

2024-02-08T20:20:11Z

Add a new generic ioctls for querying the filesystem UUID. These are lifted versions of the ext4 ioctls, with one change: we're not using a flexible array member, because UUIDs will never be more than 16 bytes. This patch adds a generic implementation of FS_IOC_GETFSUUID, which reads from super_block->s_uuid. We're not lifting SETFSUUID from ext4 - that can be done on offline filesystems by the people who need it, trying to do it online is just asking for too much trouble. Cc: Christian Brauner Cc: Jan Kara Cc: Dave Chinner Cc: Darrick J. Wong Cc: Theodore Ts'o Cc: linux-fsdevel@vger.kernel.org Signed-off-by: Kent Overstreet Link: https://lore.kernel.org/r/20240207025624.1019754-4-kent.overstreet@linux.dev Signed-off-by: Christian Brauner

vfs: add RWF_NOAPPEND flag for pwritev2

2024-01-22T14:33:37Z

The pwrite function, originally defined by POSIX (thus the "p"), is defined to ignore O_APPEND and write at the offset passed as its argument. However, historically Linux honored O_APPEND if set and ignored the offset. This cannot be changed due to stability policy, but is documented in the man page as a bug. Now that there's a pwritev2 syscall providing a superset of the pwrite functionality that has a flags argument, the conforming behavior can be offered to userspace via a new flag. Since pwritev2 checks flag validity (in kiocb_set_rw_flags) and reports unknown ones with EOPNOTSUPP, callers will not get wrong behavior on old kernels that don't support the new flag; the error is reported and the caller can decide how to handle it. Signed-off-by: Rich Felker Link: https://lore.kernel.org/r/20200831153207.GO3265@brightrain.aerifal.cx Reviewed-by: Jann Horn Signed-off-by: Christian Brauner

fs/proc/task_mmu: report SOFT_DIRTY bits through the PAGEMAP_SCAN ioctl

2023-12-11T00:51:35Z

The PAGEMAP_SCAN ioctl returns information regarding page table entries. It is more efficient compared to reading pagemap files. CRIU can start to utilize this ioctl, but it needs info about soft-dirty bits to track memory changes. We are aware of a new method for tracking memory changes implemented in the PAGEMAP_SCAN ioctl. For CRIU, the primary advantage of this method is its usability by unprivileged users. However, it is not feasible to transparently replace the soft-dirty tracker with the new one. The main problem here is userfault descriptors that have to be preserved between pre-dump iterations. It means criu continues supporting the soft-dirty method to avoid breakage for current users. The new method will be implemented as a separate feature. [avagin@google.com: update tools/include/uapi/linux/fs.h] Link: https://lkml.kernel.org/r/20231107164139.576046-1-avagin@google.com Link: https://lkml.kernel.org/r/20231106220959.296568-1-avagin@google.com Signed-off-by: Andrei Vagin Reviewed-by: Muhammad Usama Anjum Cc: Michał Mirosław Signed-off-by: Andrew Morton

fs/proc/task_mmu: implement IOCTL to get and optionally clear info about PTEs

2023-10-18T21:34:12Z

The PAGEMAP_SCAN IOCTL on the pagemap file can be used to get or optionally clear the info about page table entries. The following operations are supported in this IOCTL: - Scan the address range and get the memory ranges matching the provided criteria. This is performed when the output buffer is specified. - Write-protect the pages. The PM_SCAN_WP_MATCHING is used to write-protect the pages of interest. The PM_SCAN_CHECK_WPASYNC aborts the operation if non-Async Write Protected pages are found. The ``PM_SCAN_WP_MATCHING`` can be used with or without PM_SCAN_CHECK_WPASYNC. - Both of those operations can be combined into one atomic operation where we can get and write protect the pages as well. Following flags about pages are currently supported: - PAGE_IS_WPALLOWED - Page has async-write-protection enabled - PAGE_IS_WRITTEN - Page has been written to from the time it was write protected - PAGE_IS_FILE - Page is file backed - PAGE_IS_PRESENT - Page is present in the memory - PAGE_IS_SWAPPED - Page is in swapped - PAGE_IS_PFNZERO - Page has zero PFN - PAGE_IS_HUGE - Page is THP or Hugetlb backed This IOCTL can be extended to get information about more PTE bits. The entire address range passed by user [start, end) is scanned until either the user provided buffer is full or max_pages have been found. [akpm@linux-foundation.org: update it for "mm: hugetlb: add huge page size param to set_huge_pte_at()"] [akpm@linux-foundation.org: fix CONFIG_HUGETLB_PAGE=n warning] [arnd@arndb.de: hide unused pagemap_scan_backout_range() function] Link: https://lkml.kernel.org/r/20230927060257.2975412-1-arnd@kernel.org [sfr@canb.auug.org.au: fix "fs/proc/task_mmu: hide unused pagemap_scan_backout_range() function"] Link: https://lkml.kernel.org/r/20230928092223.0625c6bf@canb.auug.org.au Link: https://lkml.kernel.org/r/20230821141518.870589-3-usama.anjum@collabora.com Signed-off-by: Muhammad Usama Anjum Signed-off-by: Michał Mirosław Signed-off-by: Arnd Bergmann Signed-off-by: Stephen Rothwell Reviewed-by: Andrei Vagin Reviewed-by: Michał Mirosław Cc: Alex Sierra Cc: Al Viro Cc: Axel Rasmussen Cc: Christian Brauner Cc: Cyrill Gorcunov Cc: Dan Williams Cc: David Hildenbrand Cc: Greg Kroah-Hartman Cc: Gustavo A. R. Silva Cc: "Liam R. Howlett" Cc: Matthew Wilcox Cc: Michal Miroslaw Cc: Mike Rapoport (IBM) Cc: Nadav Amit Cc: Pasha Tatashin Cc: Paul Gofman Cc: Peter Xu Cc: Shuah Khan Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: Yang Shi Cc: Yun Zhou Signed-off-by: Andrew Morton

treewide: uapi: Replace zero-length arrays with flexible-array members

2022-06-28T19:26:05Z

There is a regular need in the kernel to provide a way to declare having a dynamically sized set of trailing elements in a structure. Kernel code should always use “flexible array members”[1] for these cases. The older style of one-element or zero-length arrays should no longer be used[2]. This code was transformed with the help of Coccinelle: (linux-5.19-rc2$ spatch --jobs $(getconf _NPROCESSORS_ONLN) --sp-file script.cocci --include-headers --dir . > output.patch) @@ identifier S, member, array; type T1, T2; @@ struct S { ... T1 member; T2 array[ - 0 ]; }; -fstrict-flex-arrays=3 is coming and we need to land these changes to prevent issues like these in the short future: ../fs/minix/dir.c:337:3: warning: 'strcpy' will always overflow; destination buffer has size 0, but the source string has length 2 (including NUL byte) [-Wfortify-source] strcpy(de3->name, "."); ^ Since these are all [0] to [] changes, the risk to UAPI is nearly zero. If this breaks anything, we can use a union with a new member name. [1] https://en.wikipedia.org/wiki/Flexible_array_member [2] https://www.kernel.org/doc/html/v5.16/process/deprecated.html#zero-length-and-one-element-arrays Link: https://github.com/KSPP/linux/issues/78 Build-tested-by: kernel test robot Link: https://lore.kernel.org/lkml/62b675ec.wKX6AOZ6cbE71vtF%25lkp@intel.com/ Acked-by: Dan Williams # For ndctl.h Signed-off-by: Gustavo A. R. Silva

block: add ioctl to read the disk sequence number

2021-08-02T19:37:28Z

Add a new BLKGETDISKSEQ ioctl which retrieves the disk sequence number from the genhd structure. # ./getdiskseq /dev/loop* /dev/loop0: 13 /dev/loop0p1: 13 /dev/loop0p2: 13 /dev/loop0p3: 13 /dev/loop1: 14 /dev/loop1p1: 14 /dev/loop1p2: 14 /dev/loop2: 5 /dev/loop3: 6 Reviewed-by: Christoph Hellwig Signed-off-by: Matteo Croce Tested-by: Luca Boccassi Link: https://lore.kernel.org/r/20210712230530.29323-4-mcroce@linux.microsoft.com Signed-off-by: Jens Axboe

block: uapi: fix comment about block device ioctl

2021-05-10T15:26:18Z

Fix the comment mentioning ioctl command range used for zoned block devices to reflect the range of commands actually implemented. Signed-off-by: Damien Le Moal Link: https://lore.kernel.org/r/20210509234806.3000-1-damien.lemoal@wdc.com Signed-off-by: Jens Axboe

fs/ext4: Introduce DAX inode flag

2020-05-29T02:09:47Z

Add a flag ([EXT4|FS]_DAX_FL) to preserve FS_XFLAG_DAX in the ext4 inode. Set the flag to be user visible and changeable. Set the flag to be inherited. Allow applications to change the flag at any time except if it conflicts with the set of mutually exclusive flags (Currently VERITY, ENCRYPT, JOURNAL_DATA). Furthermore, restrict setting any of the exclusive flags if DAX is set. While conceptually possible, we do not allow setting EXT4_DAX_FL while at the same time clearing exclusion flags (or vice versa) for 2 reasons: 1) The DAX flag does not take effect immediately which introduces quite a bit of complexity 2) There is no clear use case for being this flexible Finally, on regular files, flag the inode to not be cached to facilitate changing S_DAX on the next creation of the inode. Signed-off-by: Ira Weiny Link: https://lore.kernel.org/r/20200528150003.828793-9-ira.weiny@intel.com Signed-off-by: Theodore Ts'o