1

tools include UAPI: Sync linux/fcntl.h copy with the kernel sources

Picking the changes from:

  4356d575ef ("fhandle: expose u64 mount id to name_to_handle_at(2)")
  b4fef22c2f ("uapi: explain how per-syscall AT_* flags should be allocated")
  820a185896 ("fcntl: add F_CREATED_QUERY")

It just moves AT_REMOVEDIR around, and adds a bunch more AT_ for
renameat2() and name_to_handle_at(). We need to improve this situation,
as not all AT_ defines are applicable to all fs flags...

This adds support for those new AT_ defines, addressing this build
warning:

  diff -u tools/perf/trace/beauty/include/uapi/sound/asound.h include/uapi/sound/asound.h

Reviewed-by: Aleksa Sarai <cyphar@cyphar.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/lkml/ZvrIKL3cREoRHIQd@x1
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Arnaldo Carvalho de Melo 2024-09-30 12:15:18 -03:00
parent 7ae76b32f9
commit 58f969b7a8
2 changed files with 65 additions and 24 deletions

View File

@ -13,9 +13,14 @@ printf "static const char *fs_at_flags[] = {\n"
regex='^[[:space:]]*#[[:space:]]*define[[:space:]]+AT_([^_]+[[:alnum:]_]+)[[:space:]]+(0x[[:xdigit:]]+)[[:space:]]*.*'
# AT_EACCESS is only meaningful to faccessat, so we will special case it there...
# AT_STATX_SYNC_TYPE is not a bit, its a mask of AT_STATX_SYNC_AS_STAT, AT_STATX_FORCE_SYNC and AT_STATX_DONT_SYNC
# AT_HANDLE_FID and AT_HANDLE_MNT_ID_UNIQUE are reusing values and are valid only for name_to_handle_at()
# AT_RENAME_NOREPLACE reuses 0x1 and is valid only for renameat2()
grep -E $regex ${linux_fcntl} | \
grep -v AT_EACCESS | \
grep -v AT_STATX_SYNC_TYPE | \
grep -v AT_HANDLE_FID | \
grep -v AT_HANDLE_MNT_ID_UNIQUE | \
grep -v AT_RENAME_NOREPLACE | \
sed -r "s/$regex/\2 \1/g" | \
xargs printf "\t[ilog2(%s) + 1] = \"%s\",\n"
printf "};\n"

View File

@ -16,6 +16,9 @@
#define F_DUPFD_QUERY (F_LINUX_SPECIFIC_BASE + 3)
/* Was the file just created? */
#define F_CREATED_QUERY (F_LINUX_SPECIFIC_BASE + 4)
/*
* Cancel a blocking posix lock; internal use only until we expose an
* asynchronous lock api to userspace:
@ -87,37 +90,70 @@
#define DN_ATTRIB 0x00000020 /* File changed attibutes */
#define DN_MULTISHOT 0x80000000 /* Don't remove notifier */
#define AT_FDCWD -100 /* Special value for dirfd used to
indicate openat should use the
current working directory. */
/* Generic flags for the *at(2) family of syscalls. */
/* Reserved for per-syscall flags 0xff. */
#define AT_SYMLINK_NOFOLLOW 0x100 /* Do not follow symbolic
links. */
/* Reserved for per-syscall flags 0x200 */
#define AT_SYMLINK_FOLLOW 0x400 /* Follow symbolic links. */
#define AT_NO_AUTOMOUNT 0x800 /* Suppress terminal automount
traversal. */
#define AT_EMPTY_PATH 0x1000 /* Allow empty relative
pathname to operate on dirfd
directly. */
/*
* The constants AT_REMOVEDIR and AT_EACCESS have the same value. AT_EACCESS is
* meaningful only to faccessat, while AT_REMOVEDIR is meaningful only to
* unlinkat. The two functions do completely different things and therefore,
* the flags can be allowed to overlap. For example, passing AT_REMOVEDIR to
* faccessat would be undefined behavior and thus treating it equivalent to
* AT_EACCESS is valid undefined behavior.
* These flags are currently statx(2)-specific, but they could be made generic
* in the future and so they should not be used for other per-syscall flags.
*/
#define AT_FDCWD -100 /* Special value used to indicate
openat should use the current
working directory. */
#define AT_SYMLINK_NOFOLLOW 0x100 /* Do not follow symbolic links. */
#define AT_STATX_SYNC_TYPE 0x6000 /* Type of synchronisation required from statx() */
#define AT_STATX_SYNC_AS_STAT 0x0000 /* - Do whatever stat() does */
#define AT_STATX_FORCE_SYNC 0x2000 /* - Force the attributes to be sync'd with the server */
#define AT_STATX_DONT_SYNC 0x4000 /* - Don't sync attributes with the server */
#define AT_RECURSIVE 0x8000 /* Apply to the entire subtree */
/*
* Per-syscall flags for the *at(2) family of syscalls.
*
* These are flags that are so syscall-specific that a user passing these flags
* to the wrong syscall is so "clearly wrong" that we can safely call such
* usage "undefined behaviour".
*
* For example, the constants AT_REMOVEDIR and AT_EACCESS have the same value.
* AT_EACCESS is meaningful only to faccessat, while AT_REMOVEDIR is meaningful
* only to unlinkat. The two functions do completely different things and
* therefore, the flags can be allowed to overlap. For example, passing
* AT_REMOVEDIR to faccessat would be undefined behavior and thus treating it
* equivalent to AT_EACCESS is valid undefined behavior.
*
* Note for implementers: When picking a new per-syscall AT_* flag, try to
* reuse already existing flags first. This leaves us with as many unused bits
* as possible, so we can use them for generic bits in the future if necessary.
*/
/* Flags for renameat2(2) (must match legacy RENAME_* flags). */
#define AT_RENAME_NOREPLACE 0x0001
#define AT_RENAME_EXCHANGE 0x0002
#define AT_RENAME_WHITEOUT 0x0004
/* Flag for faccessat(2). */
#define AT_EACCESS 0x200 /* Test access permitted for
effective IDs, not real IDs. */
/* Flag for unlinkat(2). */
#define AT_REMOVEDIR 0x200 /* Remove directory instead of
unlinking file. */
#define AT_SYMLINK_FOLLOW 0x400 /* Follow symbolic links. */
#define AT_NO_AUTOMOUNT 0x800 /* Suppress terminal automount traversal */
#define AT_EMPTY_PATH 0x1000 /* Allow empty relative pathname */
/* Flags for name_to_handle_at(2). */
#define AT_HANDLE_FID 0x200 /* File handle is needed to compare
object identity and may not be
usable with open_by_handle_at(2). */
#define AT_HANDLE_MNT_ID_UNIQUE 0x001 /* Return the u64 unique mount ID. */
#define AT_STATX_SYNC_TYPE 0x6000 /* Type of synchronisation required from statx() */
#define AT_STATX_SYNC_AS_STAT 0x0000 /* - Do whatever stat() does */
#define AT_STATX_FORCE_SYNC 0x2000 /* - Force the attributes to be sync'd with the server */
#define AT_STATX_DONT_SYNC 0x4000 /* - Don't sync attributes with the server */
#define AT_RECURSIVE 0x8000 /* Apply to the entire subtree */
/* Flags for name_to_handle_at(2). We reuse AT_ flag space to save bits... */
#define AT_HANDLE_FID AT_REMOVEDIR /* file handle is needed to
compare object identity and may not
be usable to open_by_handle_at(2) */
#if defined(__KERNEL__)
#define AT_GETATTR_NOSEC 0x80000000
#endif