diff options
Diffstat (limited to 'include/uapi/linux/fcntl.h')
| -rw-r--r-- | include/uapi/linux/fcntl.h | 84 |
1 files changed, 60 insertions, 24 deletions
diff --git a/include/uapi/linux/fcntl.h b/include/uapi/linux/fcntl.h index c0bcc185fa48..87e2dec79fea 100644 --- a/include/uapi/linux/fcntl.h +++ b/include/uapi/linux/fcntl.h @@ -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. */ +/* + * 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_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 */ + /* - * 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. + * 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. */ -#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. */ + +/* 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 */ - -#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). */ +#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. */ -/* 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 |