* [PATCH v2] fuse: uapi: use UAPI types
@ 2025-12-30 12:10 Thomas Weißschuh
2025-12-30 21:09 ` Arnd Bergmann
` (2 more replies)
0 siblings, 3 replies; 21+ messages in thread
From: Thomas Weißschuh @ 2025-12-30 12:10 UTC (permalink / raw)
To: Miklos Szeredi
Cc: linux-fsdevel, linux-kernel, Arnd Bergmann, Thomas Weißschuh
Using libc types and headers from the UAPI headers is problematic as it
introduces a dependency on a full C toolchain.
Use the fixed-width integer types provided by the UAPI headers instead.
To keep compatibility with non-Linux platforms, add a stdint.h fallback.
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
---
Changes in v2:
- Fix structure member alignments
- Keep compatibility with non-Linux platforms
- Link to v1: https://lore.kernel.org/r/20251222-uapi-fuse-v1-1-85a61b87baa0@linutronix.de
---
include/uapi/linux/fuse.h | 626 +++++++++++++++++++++++-----------------------
1 file changed, 319 insertions(+), 307 deletions(-)
diff --git a/include/uapi/linux/fuse.h b/include/uapi/linux/fuse.h
index c13e1f9a2f12..121a1552e4cd 100644
--- a/include/uapi/linux/fuse.h
+++ b/include/uapi/linux/fuse.h
@@ -245,10 +245,22 @@
#ifndef _LINUX_FUSE_H
#define _LINUX_FUSE_H
-#ifdef __KERNEL__
+#if defined(__KERNEL__)
+#include <linux/types.h>
+#elif defined(__linux__)
#include <linux/types.h>
#else
#include <stdint.h>
+
+typedef uint8_t __u8;
+typedef uint16_t __u16;
+typedef uint32_t __u32;
+typedef uint64_t __u64;
+
+typedef int8_t __s8;
+typedef int16_t __s16;
+typedef int32_t __s32;
+typedef int64_t __s64;
#endif
/*
@@ -284,22 +296,22 @@
userspace works under 64bit kernels */
struct fuse_attr {
- uint64_t ino;
- uint64_t size;
- uint64_t blocks;
- uint64_t atime;
- uint64_t mtime;
- uint64_t ctime;
- uint32_t atimensec;
- uint32_t mtimensec;
- uint32_t ctimensec;
- uint32_t mode;
- uint32_t nlink;
- uint32_t uid;
- uint32_t gid;
- uint32_t rdev;
- uint32_t blksize;
- uint32_t flags;
+ __u64 ino;
+ __u64 size;
+ __u64 blocks;
+ __u64 atime;
+ __u64 mtime;
+ __u64 ctime;
+ __u32 atimensec;
+ __u32 mtimensec;
+ __u32 ctimensec;
+ __u32 mode;
+ __u32 nlink;
+ __u32 uid;
+ __u32 gid;
+ __u32 rdev;
+ __u32 blksize;
+ __u32 flags;
};
/*
@@ -307,53 +319,53 @@ struct fuse_attr {
* Linux.
*/
struct fuse_sx_time {
- int64_t tv_sec;
- uint32_t tv_nsec;
- int32_t __reserved;
+ __s64 tv_sec;
+ __u32 tv_nsec;
+ __s32 __reserved;
};
struct fuse_statx {
- uint32_t mask;
- uint32_t blksize;
- uint64_t attributes;
- uint32_t nlink;
- uint32_t uid;
- uint32_t gid;
- uint16_t mode;
- uint16_t __spare0[1];
- uint64_t ino;
- uint64_t size;
- uint64_t blocks;
- uint64_t attributes_mask;
+ __u32 mask;
+ __u32 blksize;
+ __u64 attributes;
+ __u32 nlink;
+ __u32 uid;
+ __u32 gid;
+ __u16 mode;
+ __u16 __spare0[1];
+ __u64 ino;
+ __u64 size;
+ __u64 blocks;
+ __u64 attributes_mask;
struct fuse_sx_time atime;
struct fuse_sx_time btime;
struct fuse_sx_time ctime;
struct fuse_sx_time mtime;
- uint32_t rdev_major;
- uint32_t rdev_minor;
- uint32_t dev_major;
- uint32_t dev_minor;
- uint64_t __spare2[14];
+ __u32 rdev_major;
+ __u32 rdev_minor;
+ __u32 dev_major;
+ __u32 dev_minor;
+ __u64 __spare2[14];
};
struct fuse_kstatfs {
- uint64_t blocks;
- uint64_t bfree;
- uint64_t bavail;
- uint64_t files;
- uint64_t ffree;
- uint32_t bsize;
- uint32_t namelen;
- uint32_t frsize;
- uint32_t padding;
- uint32_t spare[6];
+ __u64 blocks;
+ __u64 bfree;
+ __u64 bavail;
+ __u64 files;
+ __u64 ffree;
+ __u32 bsize;
+ __u32 namelen;
+ __u32 frsize;
+ __u32 padding;
+ __u32 spare[6];
};
struct fuse_file_lock {
- uint64_t start;
- uint64_t end;
- uint32_t type;
- uint32_t pid; /* tgid */
+ __u64 start;
+ __u64 end;
+ __u32 type;
+ __u32 pid; /* tgid */
};
/**
@@ -690,165 +702,165 @@ enum fuse_notify_code {
#define FUSE_COMPAT_ENTRY_OUT_SIZE 120
struct fuse_entry_out {
- uint64_t nodeid; /* Inode ID */
- uint64_t generation; /* Inode generation: nodeid:gen must
- be unique for the fs's lifetime */
- uint64_t entry_valid; /* Cache timeout for the name */
- uint64_t attr_valid; /* Cache timeout for the attributes */
- uint32_t entry_valid_nsec;
- uint32_t attr_valid_nsec;
+ __u64 nodeid; /* Inode ID */
+ __u64 generation; /* Inode generation: nodeid:gen must
+ be unique for the fs's lifetime */
+ __u64 entry_valid; /* Cache timeout for the name */
+ __u64 attr_valid; /* Cache timeout for the attributes */
+ __u32 entry_valid_nsec;
+ __u32 attr_valid_nsec;
struct fuse_attr attr;
};
struct fuse_forget_in {
- uint64_t nlookup;
+ __u64 nlookup;
};
struct fuse_forget_one {
- uint64_t nodeid;
- uint64_t nlookup;
+ __u64 nodeid;
+ __u64 nlookup;
};
struct fuse_batch_forget_in {
- uint32_t count;
- uint32_t dummy;
+ __u32 count;
+ __u32 dummy;
};
struct fuse_getattr_in {
- uint32_t getattr_flags;
- uint32_t dummy;
- uint64_t fh;
+ __u32 getattr_flags;
+ __u32 dummy;
+ __u64 fh;
};
#define FUSE_COMPAT_ATTR_OUT_SIZE 96
struct fuse_attr_out {
- uint64_t attr_valid; /* Cache timeout for the attributes */
- uint32_t attr_valid_nsec;
- uint32_t dummy;
+ __u64 attr_valid; /* Cache timeout for the attributes */
+ __u32 attr_valid_nsec;
+ __u32 dummy;
struct fuse_attr attr;
};
struct fuse_statx_in {
- uint32_t getattr_flags;
- uint32_t reserved;
- uint64_t fh;
- uint32_t sx_flags;
- uint32_t sx_mask;
+ __u32 getattr_flags;
+ __u32 reserved;
+ __u64 fh;
+ __u32 sx_flags;
+ __u32 sx_mask;
};
struct fuse_statx_out {
- uint64_t attr_valid; /* Cache timeout for the attributes */
- uint32_t attr_valid_nsec;
- uint32_t flags;
- uint64_t spare[2];
+ __u64 attr_valid; /* Cache timeout for the attributes */
+ __u32 attr_valid_nsec;
+ __u32 flags;
+ __u64 spare[2];
struct fuse_statx stat;
};
#define FUSE_COMPAT_MKNOD_IN_SIZE 8
struct fuse_mknod_in {
- uint32_t mode;
- uint32_t rdev;
- uint32_t umask;
- uint32_t padding;
+ __u32 mode;
+ __u32 rdev;
+ __u32 umask;
+ __u32 padding;
};
struct fuse_mkdir_in {
- uint32_t mode;
- uint32_t umask;
+ __u32 mode;
+ __u32 umask;
};
struct fuse_rename_in {
- uint64_t newdir;
+ __u64 newdir;
};
struct fuse_rename2_in {
- uint64_t newdir;
- uint32_t flags;
- uint32_t padding;
+ __u64 newdir;
+ __u32 flags;
+ __u32 padding;
};
struct fuse_link_in {
- uint64_t oldnodeid;
+ __u64 oldnodeid;
};
struct fuse_setattr_in {
- uint32_t valid;
- uint32_t padding;
- uint64_t fh;
- uint64_t size;
- uint64_t lock_owner;
- uint64_t atime;
- uint64_t mtime;
- uint64_t ctime;
- uint32_t atimensec;
- uint32_t mtimensec;
- uint32_t ctimensec;
- uint32_t mode;
- uint32_t unused4;
- uint32_t uid;
- uint32_t gid;
- uint32_t unused5;
+ __u32 valid;
+ __u32 padding;
+ __u64 fh;
+ __u64 size;
+ __u64 lock_owner;
+ __u64 atime;
+ __u64 mtime;
+ __u64 ctime;
+ __u32 atimensec;
+ __u32 mtimensec;
+ __u32 ctimensec;
+ __u32 mode;
+ __u32 unused4;
+ __u32 uid;
+ __u32 gid;
+ __u32 unused5;
};
struct fuse_open_in {
- uint32_t flags;
- uint32_t open_flags; /* FUSE_OPEN_... */
+ __u32 flags;
+ __u32 open_flags; /* FUSE_OPEN_... */
};
struct fuse_create_in {
- uint32_t flags;
- uint32_t mode;
- uint32_t umask;
- uint32_t open_flags; /* FUSE_OPEN_... */
+ __u32 flags;
+ __u32 mode;
+ __u32 umask;
+ __u32 open_flags; /* FUSE_OPEN_... */
};
struct fuse_open_out {
- uint64_t fh;
- uint32_t open_flags;
- int32_t backing_id;
+ __u64 fh;
+ __u32 open_flags;
+ __s32 backing_id;
};
struct fuse_release_in {
- uint64_t fh;
- uint32_t flags;
- uint32_t release_flags;
- uint64_t lock_owner;
+ __u64 fh;
+ __u32 flags;
+ __u32 release_flags;
+ __u64 lock_owner;
};
struct fuse_flush_in {
- uint64_t fh;
- uint32_t unused;
- uint32_t padding;
- uint64_t lock_owner;
+ __u64 fh;
+ __u32 unused;
+ __u32 padding;
+ __u64 lock_owner;
};
struct fuse_read_in {
- uint64_t fh;
- uint64_t offset;
- uint32_t size;
- uint32_t read_flags;
- uint64_t lock_owner;
- uint32_t flags;
- uint32_t padding;
+ __u64 fh;
+ __u64 offset;
+ __u32 size;
+ __u32 read_flags;
+ __u64 lock_owner;
+ __u32 flags;
+ __u32 padding;
};
#define FUSE_COMPAT_WRITE_IN_SIZE 24
struct fuse_write_in {
- uint64_t fh;
- uint64_t offset;
- uint32_t size;
- uint32_t write_flags;
- uint64_t lock_owner;
- uint32_t flags;
- uint32_t padding;
+ __u64 fh;
+ __u64 offset;
+ __u32 size;
+ __u32 write_flags;
+ __u64 lock_owner;
+ __u32 flags;
+ __u32 padding;
};
struct fuse_write_out {
- uint32_t size;
- uint32_t padding;
+ __u32 size;
+ __u32 padding;
};
#define FUSE_COMPAT_STATFS_SIZE 48
@@ -858,36 +870,36 @@ struct fuse_statfs_out {
};
struct fuse_fsync_in {
- uint64_t fh;
- uint32_t fsync_flags;
- uint32_t padding;
+ __u64 fh;
+ __u32 fsync_flags;
+ __u32 padding;
};
#define FUSE_COMPAT_SETXATTR_IN_SIZE 8
struct fuse_setxattr_in {
- uint32_t size;
- uint32_t flags;
- uint32_t setxattr_flags;
- uint32_t padding;
+ __u32 size;
+ __u32 flags;
+ __u32 setxattr_flags;
+ __u32 padding;
};
struct fuse_getxattr_in {
- uint32_t size;
- uint32_t padding;
+ __u32 size;
+ __u32 padding;
};
struct fuse_getxattr_out {
- uint32_t size;
- uint32_t padding;
+ __u32 size;
+ __u32 padding;
};
struct fuse_lk_in {
- uint64_t fh;
- uint64_t owner;
+ __u64 fh;
+ __u64 owner;
struct fuse_file_lock lk;
- uint32_t lk_flags;
- uint32_t padding;
+ __u32 lk_flags;
+ __u32 padding;
};
struct fuse_lk_out {
@@ -895,117 +907,117 @@ struct fuse_lk_out {
};
struct fuse_access_in {
- uint32_t mask;
- uint32_t padding;
+ __u32 mask;
+ __u32 padding;
};
struct fuse_init_in {
- uint32_t major;
- uint32_t minor;
- uint32_t max_readahead;
- uint32_t flags;
- uint32_t flags2;
- uint32_t unused[11];
+ __u32 major;
+ __u32 minor;
+ __u32 max_readahead;
+ __u32 flags;
+ __u32 flags2;
+ __u32 unused[11];
};
#define FUSE_COMPAT_INIT_OUT_SIZE 8
#define FUSE_COMPAT_22_INIT_OUT_SIZE 24
struct fuse_init_out {
- uint32_t major;
- uint32_t minor;
- uint32_t max_readahead;
- uint32_t flags;
- uint16_t max_background;
- uint16_t congestion_threshold;
- uint32_t max_write;
- uint32_t time_gran;
- uint16_t max_pages;
- uint16_t map_alignment;
- uint32_t flags2;
- uint32_t max_stack_depth;
- uint16_t request_timeout;
- uint16_t unused[11];
+ __u32 major;
+ __u32 minor;
+ __u32 max_readahead;
+ __u32 flags;
+ __u16 max_background;
+ __u16 congestion_threshold;
+ __u32 max_write;
+ __u32 time_gran;
+ __u16 max_pages;
+ __u16 map_alignment;
+ __u32 flags2;
+ __u32 max_stack_depth;
+ __u16 request_timeout;
+ __u16 unused[11];
};
#define CUSE_INIT_INFO_MAX 4096
struct cuse_init_in {
- uint32_t major;
- uint32_t minor;
- uint32_t unused;
- uint32_t flags;
+ __u32 major;
+ __u32 minor;
+ __u32 unused;
+ __u32 flags;
};
struct cuse_init_out {
- uint32_t major;
- uint32_t minor;
- uint32_t unused;
- uint32_t flags;
- uint32_t max_read;
- uint32_t max_write;
- uint32_t dev_major; /* chardev major */
- uint32_t dev_minor; /* chardev minor */
- uint32_t spare[10];
+ __u32 major;
+ __u32 minor;
+ __u32 unused;
+ __u32 flags;
+ __u32 max_read;
+ __u32 max_write;
+ __u32 dev_major; /* chardev major */
+ __u32 dev_minor; /* chardev minor */
+ __u32 spare[10];
};
struct fuse_interrupt_in {
- uint64_t unique;
+ __u64 unique;
};
struct fuse_bmap_in {
- uint64_t block;
- uint32_t blocksize;
- uint32_t padding;
+ __u64 block;
+ __u32 blocksize;
+ __u32 padding;
};
struct fuse_bmap_out {
- uint64_t block;
+ __u64 block;
};
struct fuse_ioctl_in {
- uint64_t fh;
- uint32_t flags;
- uint32_t cmd;
- uint64_t arg;
- uint32_t in_size;
- uint32_t out_size;
+ __u64 fh;
+ __u32 flags;
+ __u32 cmd;
+ __u64 arg;
+ __u32 in_size;
+ __u32 out_size;
};
struct fuse_ioctl_iovec {
- uint64_t base;
- uint64_t len;
+ __u64 base;
+ __u64 len;
};
struct fuse_ioctl_out {
- int32_t result;
- uint32_t flags;
- uint32_t in_iovs;
- uint32_t out_iovs;
+ __s32 result;
+ __u32 flags;
+ __u32 in_iovs;
+ __u32 out_iovs;
};
struct fuse_poll_in {
- uint64_t fh;
- uint64_t kh;
- uint32_t flags;
- uint32_t events;
+ __u64 fh;
+ __u64 kh;
+ __u32 flags;
+ __u32 events;
};
struct fuse_poll_out {
- uint32_t revents;
- uint32_t padding;
+ __u32 revents;
+ __u32 padding;
};
struct fuse_notify_poll_wakeup_out {
- uint64_t kh;
+ __u64 kh;
};
struct fuse_fallocate_in {
- uint64_t fh;
- uint64_t offset;
- uint64_t length;
- uint32_t mode;
- uint32_t padding;
+ __u64 fh;
+ __u64 offset;
+ __u64 length;
+ __u32 mode;
+ __u32 padding;
};
/**
@@ -1029,37 +1041,37 @@ struct fuse_fallocate_in {
* FUSE_MKNOD, FUSE_SYMLINK, FUSE_MKDIR, FUSE_TMPFILE,
* FUSE_CREATE and FUSE_RENAME2 (with RENAME_WHITEOUT).
*/
-#define FUSE_INVALID_UIDGID ((uint32_t)(-1))
+#define FUSE_INVALID_UIDGID ((__u32)(-1))
struct fuse_in_header {
- uint32_t len;
- uint32_t opcode;
- uint64_t unique;
- uint64_t nodeid;
- uint32_t uid;
- uint32_t gid;
- uint32_t pid;
- uint16_t total_extlen; /* length of extensions in 8byte units */
- uint16_t padding;
+ __u32 len;
+ __u32 opcode;
+ __u64 unique;
+ __u64 nodeid;
+ __u32 uid;
+ __u32 gid;
+ __u32 pid;
+ __u16 total_extlen; /* length of extensions in 8byte units */
+ __u16 padding;
};
struct fuse_out_header {
- uint32_t len;
- int32_t error;
- uint64_t unique;
+ __u32 len;
+ __s32 error;
+ __u64 unique;
};
struct fuse_dirent {
- uint64_t ino;
- uint64_t off;
- uint32_t namelen;
- uint32_t type;
+ __u64 ino;
+ __u64 off;
+ __u32 namelen;
+ __u32 type;
char name[];
};
/* Align variable length records to 64bit boundary */
#define FUSE_REC_ALIGN(x) \
- (((x) + sizeof(uint64_t) - 1) & ~(sizeof(uint64_t) - 1))
+ (((x) + sizeof(__u64) - 1) & ~(sizeof(__u64) - 1))
#define FUSE_NAME_OFFSET offsetof(struct fuse_dirent, name)
#define FUSE_DIRENT_ALIGN(x) FUSE_REC_ALIGN(x)
@@ -1077,127 +1089,127 @@ struct fuse_direntplus {
FUSE_DIRENT_ALIGN(FUSE_NAME_OFFSET_DIRENTPLUS + (d)->dirent.namelen)
struct fuse_notify_inval_inode_out {
- uint64_t ino;
- int64_t off;
- int64_t len;
+ __u64 ino;
+ __s64 off;
+ __s64 len;
};
struct fuse_notify_inval_entry_out {
- uint64_t parent;
- uint32_t namelen;
- uint32_t flags;
+ __u64 parent;
+ __u32 namelen;
+ __u32 flags;
};
struct fuse_notify_delete_out {
- uint64_t parent;
- uint64_t child;
- uint32_t namelen;
- uint32_t padding;
+ __u64 parent;
+ __u64 child;
+ __u32 namelen;
+ __u32 padding;
};
struct fuse_notify_store_out {
- uint64_t nodeid;
- uint64_t offset;
- uint32_t size;
- uint32_t padding;
+ __u64 nodeid;
+ __u64 offset;
+ __u32 size;
+ __u32 padding;
};
struct fuse_notify_retrieve_out {
- uint64_t notify_unique;
- uint64_t nodeid;
- uint64_t offset;
- uint32_t size;
- uint32_t padding;
+ __u64 notify_unique;
+ __u64 nodeid;
+ __u64 offset;
+ __u32 size;
+ __u32 padding;
};
/* Matches the size of fuse_write_in */
struct fuse_notify_retrieve_in {
- uint64_t dummy1;
- uint64_t offset;
- uint32_t size;
- uint32_t dummy2;
- uint64_t dummy3;
- uint64_t dummy4;
+ __u64 dummy1;
+ __u64 offset;
+ __u32 size;
+ __u32 dummy2;
+ __u64 dummy3;
+ __u64 dummy4;
};
struct fuse_notify_prune_out {
- uint32_t count;
- uint32_t padding;
- uint64_t spare;
+ __u32 count;
+ __u32 padding;
+ __u64 spare;
};
struct fuse_backing_map {
- int32_t fd;
- uint32_t flags;
- uint64_t padding;
+ __s32 fd;
+ __u32 flags;
+ __u64 padding;
};
/* Device ioctls: */
#define FUSE_DEV_IOC_MAGIC 229
-#define FUSE_DEV_IOC_CLONE _IOR(FUSE_DEV_IOC_MAGIC, 0, uint32_t)
+#define FUSE_DEV_IOC_CLONE _IOR(FUSE_DEV_IOC_MAGIC, 0, __u32)
#define FUSE_DEV_IOC_BACKING_OPEN _IOW(FUSE_DEV_IOC_MAGIC, 1, \
struct fuse_backing_map)
-#define FUSE_DEV_IOC_BACKING_CLOSE _IOW(FUSE_DEV_IOC_MAGIC, 2, uint32_t)
+#define FUSE_DEV_IOC_BACKING_CLOSE _IOW(FUSE_DEV_IOC_MAGIC, 2, __u32)
#define FUSE_DEV_IOC_SYNC_INIT _IO(FUSE_DEV_IOC_MAGIC, 3)
struct fuse_lseek_in {
- uint64_t fh;
- uint64_t offset;
- uint32_t whence;
- uint32_t padding;
+ __u64 fh;
+ __u64 offset;
+ __u32 whence;
+ __u32 padding;
};
struct fuse_lseek_out {
- uint64_t offset;
+ __u64 offset;
};
struct fuse_copy_file_range_in {
- uint64_t fh_in;
- uint64_t off_in;
- uint64_t nodeid_out;
- uint64_t fh_out;
- uint64_t off_out;
- uint64_t len;
- uint64_t flags;
+ __u64 fh_in;
+ __u64 off_in;
+ __u64 nodeid_out;
+ __u64 fh_out;
+ __u64 off_out;
+ __u64 len;
+ __u64 flags;
};
/* For FUSE_COPY_FILE_RANGE_64 */
struct fuse_copy_file_range_out {
- uint64_t bytes_copied;
+ __u64 bytes_copied;
};
#define FUSE_SETUPMAPPING_FLAG_WRITE (1ull << 0)
#define FUSE_SETUPMAPPING_FLAG_READ (1ull << 1)
struct fuse_setupmapping_in {
/* An already open handle */
- uint64_t fh;
+ __u64 fh;
/* Offset into the file to start the mapping */
- uint64_t foffset;
+ __u64 foffset;
/* Length of mapping required */
- uint64_t len;
+ __u64 len;
/* Flags, FUSE_SETUPMAPPING_FLAG_* */
- uint64_t flags;
+ __u64 flags;
/* Offset in Memory Window */
- uint64_t moffset;
+ __u64 moffset;
};
struct fuse_removemapping_in {
/* number of fuse_removemapping_one follows */
- uint32_t count;
+ __u32 count;
};
struct fuse_removemapping_one {
/* Offset into the dax window start the unmapping */
- uint64_t moffset;
+ __u64 moffset;
/* Length of mapping required */
- uint64_t len;
+ __u64 len;
};
#define FUSE_REMOVEMAPPING_MAX_ENTRY \
(PAGE_SIZE / sizeof(struct fuse_removemapping_one))
struct fuse_syncfs_in {
- uint64_t padding;
+ __u64 padding;
};
/*
@@ -1207,8 +1219,8 @@ struct fuse_syncfs_in {
* fuse_secctx, name, context
*/
struct fuse_secctx {
- uint32_t size;
- uint32_t padding;
+ __u32 size;
+ __u32 padding;
};
/*
@@ -1218,8 +1230,8 @@ struct fuse_secctx {
*
*/
struct fuse_secctx_header {
- uint32_t size;
- uint32_t nr_secctx;
+ __u32 size;
+ __u32 nr_secctx;
};
/**
@@ -1231,8 +1243,8 @@ struct fuse_secctx_header {
* FUSE_MAX_NR_SECCTX
*/
struct fuse_ext_header {
- uint32_t size;
- uint32_t type;
+ __u32 size;
+ __u32 type;
};
/**
@@ -1241,8 +1253,8 @@ struct fuse_ext_header {
* @groups: flexible array of group IDs
*/
struct fuse_supp_groups {
- uint32_t nr_groups;
- uint32_t groups[];
+ __u32 nr_groups;
+ __u32 groups[];
};
/**
@@ -1253,19 +1265,19 @@ struct fuse_supp_groups {
/* Used as part of the fuse_uring_req_header */
struct fuse_uring_ent_in_out {
- uint64_t flags;
+ __u64 flags;
/*
* commit ID to be used in a reply to a ring request (see also
* struct fuse_uring_cmd_req)
*/
- uint64_t commit_id;
+ __u64 commit_id;
/* size of user payload buffer */
- uint32_t payload_sz;
- uint32_t padding;
+ __u32 payload_sz;
+ __u32 padding;
- uint64_t reserved;
+ __u64 reserved;
};
/**
@@ -1298,14 +1310,14 @@ enum fuse_uring_cmd {
* In the 80B command area of the SQE.
*/
struct fuse_uring_cmd_req {
- uint64_t flags;
+ __u64 flags;
/* entry identifier for commits */
- uint64_t commit_id;
+ __u64 commit_id;
/* queue the command is for (queue index) */
- uint16_t qid;
- uint8_t padding[6];
+ __u16 qid;
+ __u8 padding[6];
};
#endif /* _LINUX_FUSE_H */
---
base-commit: 8f0b4cce4481fb22653697cced8d0d04027cb1e8
change-id: 20251222-uapi-fuse-1acdfb5abf77
Best regards,
--
Thomas Weißschuh <thomas.weissschuh@linutronix.de>
^ permalink raw reply related [flat|nested] 21+ messages in thread
* Re: [PATCH v2] fuse: uapi: use UAPI types
2025-12-30 12:10 [PATCH v2] fuse: uapi: use UAPI types Thomas Weißschuh
@ 2025-12-30 21:09 ` Arnd Bergmann
2026-01-02 22:27 ` Bernd Schubert
2026-01-05 12:45 ` Miklos Szeredi
2 siblings, 0 replies; 21+ messages in thread
From: Arnd Bergmann @ 2025-12-30 21:09 UTC (permalink / raw)
To: Thomas Weißschuh, Miklos Szeredi; +Cc: linux-fsdevel, linux-kernel
On Tue, Dec 30, 2025, at 13:10, Thomas Weißschuh wrote:
> Using libc types and headers from the UAPI headers is problematic as it
> introduces a dependency on a full C toolchain.
>
> Use the fixed-width integer types provided by the UAPI headers instead.
> To keep compatibility with non-Linux platforms, add a stdint.h fallback.
>
> Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
^ permalink raw reply [flat|nested] 21+ messages in thread
* Re: [PATCH v2] fuse: uapi: use UAPI types
2025-12-30 12:10 [PATCH v2] fuse: uapi: use UAPI types Thomas Weißschuh
2025-12-30 21:09 ` Arnd Bergmann
@ 2026-01-02 22:27 ` Bernd Schubert
2026-01-03 12:44 ` Bernd Schubert
2026-01-03 14:10 ` David Laight
2026-01-05 12:45 ` Miklos Szeredi
2 siblings, 2 replies; 21+ messages in thread
From: Bernd Schubert @ 2026-01-02 22:27 UTC (permalink / raw)
To: Thomas Weißschuh, Miklos Szeredi
Cc: linux-fsdevel, linux-kernel, Arnd Bergmann
On 12/30/25 13:10, Thomas Weißschuh wrote:
> Using libc types and headers from the UAPI headers is problematic as it
> introduces a dependency on a full C toolchain.
>
> Use the fixed-width integer types provided by the UAPI headers instead.
> To keep compatibility with non-Linux platforms, add a stdint.h fallback.
>
> Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
> ---
> Changes in v2:
> - Fix structure member alignments
> - Keep compatibility with non-Linux platforms
> - Link to v1: https://lore.kernel.org/r/20251222-uapi-fuse-v1-1-85a61b87baa0@linutronix.de
> ---
> include/uapi/linux/fuse.h | 626 +++++++++++++++++++++++-----------------------
> 1 file changed, 319 insertions(+), 307 deletions(-)
I tested this and it breaks libfuse compilation
https://github.com/libfuse/libfuse/pull/1410
Any chance you could test libfuse compilation for v3? Easiest way is to
copy it to <libfuse>/include/fuse_kernel.h and then create PR. That
includes a BSD test.
libfuse3.so.3.19.0.p/fuse_uring.c.o -c
../../../home/runner/work/libfuse/libfuse/lib/fuse_uring.c
../../../home/runner/work/libfuse/libfuse/lib/fuse_uring.c:197:5: error:
format specifies type 'unsigned long' but the argument has type '__u64'
(aka 'unsigned long long') [-Werror,-Wformat]
196 | fuse_log(FUSE_LOG_DEBUG, " unique: %" PRIu64
", result=%d\n",
| ~~~~~~~~~
197 | out->unique, ent_in_out->payload_sz);
| ^~~~~~~~~~~
1 error generated.
I can certainly work it around in libfuse by adding a cast, IMHO,
PRIu64 is the right format.
Thanks,
Bernd
^ permalink raw reply [flat|nested] 21+ messages in thread
* Re: [PATCH v2] fuse: uapi: use UAPI types
2026-01-02 22:27 ` Bernd Schubert
@ 2026-01-03 12:44 ` Bernd Schubert
2026-01-05 8:40 ` Thomas Weißschuh
2026-01-03 14:10 ` David Laight
1 sibling, 1 reply; 21+ messages in thread
From: Bernd Schubert @ 2026-01-03 12:44 UTC (permalink / raw)
To: Thomas Weißschuh, Miklos Szeredi
Cc: linux-fsdevel, linux-kernel, Arnd Bergmann
[-- Attachment #1: Type: text/plain, Size: 2421 bytes --]
On 1/2/26 23:27, Bernd Schubert wrote:
>
>
> On 12/30/25 13:10, Thomas Weißschuh wrote:
>> Using libc types and headers from the UAPI headers is problematic as it
>> introduces a dependency on a full C toolchain.
>>
>> Use the fixed-width integer types provided by the UAPI headers instead.
>> To keep compatibility with non-Linux platforms, add a stdint.h fallback.
>>
>> Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
>> ---
>> Changes in v2:
>> - Fix structure member alignments
>> - Keep compatibility with non-Linux platforms
>> - Link to v1: https://lore.kernel.org/r/20251222-uapi-fuse-v1-1-85a61b87baa0@linutronix.de
>> ---
>> include/uapi/linux/fuse.h | 626 +++++++++++++++++++++++-----------------------
>> 1 file changed, 319 insertions(+), 307 deletions(-)
>
> I tested this and it breaks libfuse compilation
>
> https://github.com/libfuse/libfuse/pull/1410
>
> Any chance you could test libfuse compilation for v3? Easiest way is to
> copy it to <libfuse>/include/fuse_kernel.h and then create PR. That
> includes a BSD test.
>
>
> libfuse3.so.3.19.0.p/fuse_uring.c.o -c
> ../../../home/runner/work/libfuse/libfuse/lib/fuse_uring.c
> ../../../home/runner/work/libfuse/libfuse/lib/fuse_uring.c:197:5: error:
> format specifies type 'unsigned long' but the argument has type '__u64'
> (aka 'unsigned long long') [-Werror,-Wformat]
> 196 | fuse_log(FUSE_LOG_DEBUG, " unique: %" PRIu64
> ", result=%d\n",
> | ~~~~~~~~~
> 197 | out->unique, ent_in_out->payload_sz);
> | ^~~~~~~~~~~
> 1 error generated.
>
>
> I can certainly work it around in libfuse by adding a cast, IMHO,
> PRIu64 is the right format.
>
I think what would work is the attached version. Short interesting part
#if defined(__KERNEL__)
#include <linux/types.h>
typedef __u8 fuse_u8;
typedef __u16 fuse_u16;
typedef __u32 fuse_u32;
typedef __u64 fuse_u64;
typedef __s8 fuse_s8;
typedef __s16 fuse_s16;
typedef __s32 fuse_s32;
typedef __s64 fuse_s64;
#else
#include <stdint.h>
typedef uint8_t fuse_u8;
typedef uint16_t fuse_u16;
typedef uint32_t fuse_u32;
typedef uint64_t fuse_u64;
typedef int8_t fuse_s8;
typedef int16_t fuse_s16;
typedef int32_t fuse_s32;
typedef int64_t fuse_s64;
#endif
And then the rest of the file has to use the fuse_ types.
Thanks,
Bernd
[-- Attachment #2: fuse_kernel.h --]
[-- Type: text/x-chdr, Size: 32322 bytes --]
/* SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) */
/*
This file defines the kernel interface of FUSE
Copyright (C) 2001-2008 Miklos Szeredi <miklos@szeredi.hu>
This program can be distributed under the terms of the GNU GPL.
See the file COPYING.
This -- and only this -- header file may also be distributed under
the terms of the BSD Licence as follows:
Copyright (C) 2001-2007 Miklos Szeredi. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
SUCH DAMAGE.
*/
/*
* This file defines the kernel interface of FUSE
*
* Protocol changelog:
*
* 7.1:
* - add the following messages:
* FUSE_SETATTR, FUSE_SYMLINK, FUSE_MKNOD, FUSE_MKDIR, FUSE_UNLINK,
* FUSE_RMDIR, FUSE_RENAME, FUSE_LINK, FUSE_OPEN, FUSE_READ, FUSE_WRITE,
* FUSE_RELEASE, FUSE_FSYNC, FUSE_FLUSH, FUSE_SETXATTR, FUSE_GETXATTR,
* FUSE_LISTXATTR, FUSE_REMOVEXATTR, FUSE_OPENDIR, FUSE_READDIR,
* FUSE_RELEASEDIR
* - add padding to messages to accommodate 32-bit servers on 64-bit kernels
*
* 7.2:
* - add FOPEN_DIRECT_IO and FOPEN_KEEP_CACHE flags
* - add FUSE_FSYNCDIR message
*
* 7.3:
* - add FUSE_ACCESS message
* - add FUSE_CREATE message
* - add filehandle to fuse_setattr_in
*
* 7.4:
* - add frsize to fuse_kstatfs
* - clean up request size limit checking
*
* 7.5:
* - add flags and max_write to fuse_init_out
*
* 7.6:
* - add max_readahead to fuse_init_in and fuse_init_out
*
* 7.7:
* - add FUSE_INTERRUPT message
* - add POSIX file lock support
*
* 7.8:
* - add lock_owner and flags fields to fuse_release_in
* - add FUSE_BMAP message
* - add FUSE_DESTROY message
*
* 7.9:
* - new fuse_getattr_in input argument of GETATTR
* - add lk_flags in fuse_lk_in
* - add lock_owner field to fuse_setattr_in, fuse_read_in and fuse_write_in
* - add blksize field to fuse_attr
* - add file flags field to fuse_read_in and fuse_write_in
* - Add ATIME_NOW and MTIME_NOW flags to fuse_setattr_in
*
* 7.10
* - add nonseekable open flag
*
* 7.11
* - add IOCTL message
* - add unsolicited notification support
* - add POLL message and NOTIFY_POLL notification
*
* 7.12
* - add umask flag to input argument of create, mknod and mkdir
* - add notification messages for invalidation of inodes and
* directory entries
*
* 7.13
* - make max number of background requests and congestion threshold
* tunables
*
* 7.14
* - add splice support to fuse device
*
* 7.15
* - add store notify
* - add retrieve notify
*
* 7.16
* - add BATCH_FORGET request
* - FUSE_IOCTL_UNRESTRICTED shall now return with array of 'struct
* fuse_ioctl_iovec' instead of ambiguous 'struct iovec'
* - add FUSE_IOCTL_32BIT flag
*
* 7.17
* - add FUSE_FLOCK_LOCKS and FUSE_RELEASE_FLOCK_UNLOCK
*
* 7.18
* - add FUSE_IOCTL_DIR flag
* - add FUSE_NOTIFY_DELETE
*
* 7.19
* - add FUSE_FALLOCATE
*
* 7.20
* - add FUSE_AUTO_INVAL_DATA
*
* 7.21
* - add FUSE_READDIRPLUS
* - send the requested events in POLL request
*
* 7.22
* - add FUSE_ASYNC_DIO
*
* 7.23
* - add FUSE_WRITEBACK_CACHE
* - add time_gran to fuse_init_out
* - add reserved space to fuse_init_out
* - add FATTR_CTIME
* - add ctime and ctimensec to fuse_setattr_in
* - add FUSE_RENAME2 request
* - add FUSE_NO_OPEN_SUPPORT flag
*
* 7.24
* - add FUSE_LSEEK for SEEK_HOLE and SEEK_DATA support
*
* 7.25
* - add FUSE_PARALLEL_DIROPS
*
* 7.26
* - add FUSE_HANDLE_KILLPRIV
* - add FUSE_POSIX_ACL
*
* 7.27
* - add FUSE_ABORT_ERROR
*
* 7.28
* - add FUSE_COPY_FILE_RANGE
* - add FOPEN_CACHE_DIR
* - add FUSE_MAX_PAGES, add max_pages to init_out
* - add FUSE_CACHE_SYMLINKS
*
* 7.29
* - add FUSE_NO_OPENDIR_SUPPORT flag
*
* 7.30
* - add FUSE_EXPLICIT_INVAL_DATA
* - add FUSE_IOCTL_COMPAT_X32
*
* 7.31
* - add FUSE_WRITE_KILL_PRIV flag
* - add FUSE_SETUPMAPPING and FUSE_REMOVEMAPPING
* - add map_alignment to fuse_init_out, add FUSE_MAP_ALIGNMENT flag
*
* 7.32
* - add flags to fuse_attr, add FUSE_ATTR_SUBMOUNT, add FUSE_SUBMOUNTS
*
* 7.33
* - add FUSE_HANDLE_KILLPRIV_V2, FUSE_WRITE_KILL_SUIDGID, FATTR_KILL_SUIDGID
* - add FUSE_OPEN_KILL_SUIDGID
* - extend fuse_setxattr_in, add FUSE_SETXATTR_EXT
* - add FUSE_SETXATTR_ACL_KILL_SGID
*
* 7.34
* - add FUSE_SYNCFS
*
* 7.35
* - add FOPEN_NOFLUSH
*
* 7.36
* - extend fuse_init_in with reserved fields, add FUSE_INIT_EXT init flag
* - add flags2 to fuse_init_in and fuse_init_out
* - add FUSE_SECURITY_CTX init flag
* - add security context to create, mkdir, symlink, and mknod requests
* - add FUSE_HAS_INODE_DAX, FUSE_ATTR_DAX
*
* 7.37
* - add FUSE_TMPFILE
*
* 7.38
* - add FUSE_EXPIRE_ONLY flag to fuse_notify_inval_entry
* - add FOPEN_PARALLEL_DIRECT_WRITES
* - add total_extlen to fuse_in_header
* - add FUSE_MAX_NR_SECCTX
* - add extension header
* - add FUSE_EXT_GROUPS
* - add FUSE_CREATE_SUPP_GROUP
* - add FUSE_HAS_EXPIRE_ONLY
*
* 7.39
* - add FUSE_DIRECT_IO_ALLOW_MMAP
* - add FUSE_STATX and related structures
*
* 7.40
* - add max_stack_depth to fuse_init_out, add FUSE_PASSTHROUGH init flag
* - add backing_id to fuse_open_out, add FOPEN_PASSTHROUGH open flag
* - add FUSE_NO_EXPORT_SUPPORT init flag
* - add FUSE_NOTIFY_RESEND, add FUSE_HAS_RESEND init flag
*
* 7.41
* - add FUSE_ALLOW_IDMAP
* 7.42
* - Add FUSE_OVER_IO_URING and all other io-uring related flags and data
* structures:
* - struct fuse_uring_ent_in_out
* - struct fuse_uring_req_header
* - struct fuse_uring_cmd_req
* - FUSE_URING_IN_OUT_HEADER_SZ
* - FUSE_URING_OP_IN_OUT_SZ
* - enum fuse_uring_cmd
*
* 7.43
* - add FUSE_REQUEST_TIMEOUT
*
* 7.44
* - add FUSE_NOTIFY_INC_EPOCH
*
* 7.45
* - add FUSE_COPY_FILE_RANGE_64
* - add struct fuse_copy_file_range_out
* - add FUSE_NOTIFY_PRUNE
*/
#ifndef _LINUX_FUSE_H
#define _LINUX_FUSE_H
#if defined(__KERNEL__)
#include <linux/types.h>
typedef __u8 fuse_u8;
typedef __u16 fuse_u16;
typedef __u32 fuse_u32;
typedef __u64 fuse_u64;
typedef __s8 fuse_s8;
typedef __s16 fuse_s16;
typedef __s32 fuse_s32;
typedef __s64 fuse_s64;
#else
#include <stdint.h>
typedef uint8_t fuse_u8;
typedef uint16_t fuse_u16;
typedef uint32_t fuse_u32;
typedef uint64_t fuse_u64;
typedef int8_t fuse_s8;
typedef int16_t fuse_s16;
typedef int32_t fuse_s32;
typedef int64_t fuse_s64;
#endif
/*
* Version negotiation:
*
* Both the kernel and userspace send the version they support in the
* INIT request and reply respectively.
*
* If the major versions match then both shall use the smallest
* of the two minor versions for communication.
*
* If the kernel supports a larger major version, then userspace shall
* reply with the major version it supports, ignore the rest of the
* INIT message and expect a new INIT message from the kernel with a
* matching major version.
*
* If the library supports a larger major version, then it shall fall
* back to the major protocol version sent by the kernel for
* communication and reply with that major version (and an arbitrary
* supported minor version).
*/
/** Version number of this interface */
#define FUSE_KERNEL_VERSION 7
/** Minor version number of this interface */
#define FUSE_KERNEL_MINOR_VERSION 45
/** The node ID of the root inode */
#define FUSE_ROOT_ID 1
/* Make sure all structures are padded to 64bit boundary, so 32bit
userspace works under 64bit kernels */
struct fuse_attr {
fuse_u64 ino;
fuse_u64 size;
fuse_u64 blocks;
fuse_u64 atime;
fuse_u64 mtime;
fuse_u64 ctime;
fuse_u32 atimensec;
fuse_u32 mtimensec;
fuse_u32 ctimensec;
fuse_u32 mode;
fuse_u32 nlink;
fuse_u32 uid;
fuse_u32 gid;
fuse_u32 rdev;
fuse_u32 blksize;
fuse_u32 flags;
};
/*
* The following structures are bit-for-bit compatible with the statx(2) ABI in
* Linux.
*/
struct fuse_sx_time {
fuse_s64 tv_sec;
fuse_u32 tv_nsec;
fuse_s32 __reserved;
};
struct fuse_statx {
fuse_u32 mask;
fuse_u32 blksize;
fuse_u64 attributes;
fuse_u32 nlink;
fuse_u32 uid;
fuse_u32 gid;
fuse_u16 mode;
fuse_u16 __spare0[1];
fuse_u64 ino;
fuse_u64 size;
fuse_u64 blocks;
fuse_u64 attributes_mask;
struct fuse_sx_time atime;
struct fuse_sx_time btime;
struct fuse_sx_time ctime;
struct fuse_sx_time mtime;
fuse_u32 rdev_major;
fuse_u32 rdev_minor;
fuse_u32 dev_major;
fuse_u32 dev_minor;
fuse_u64 __spare2[14];
};
struct fuse_kstatfs {
fuse_u64 blocks;
fuse_u64 bfree;
fuse_u64 bavail;
fuse_u64 files;
fuse_u64 ffree;
fuse_u32 bsize;
fuse_u32 namelen;
fuse_u32 frsize;
fuse_u32 padding;
fuse_u32 spare[6];
};
struct fuse_file_lock {
fuse_u64 start;
fuse_u64 end;
fuse_u32 type;
fuse_u32 pid; /* tgid */
};
/**
* Bitmasks for fuse_setattr_in.valid
*/
#define FATTR_MODE (1 << 0)
#define FATTR_UID (1 << 1)
#define FATTR_GID (1 << 2)
#define FATTR_SIZE (1 << 3)
#define FATTR_ATIME (1 << 4)
#define FATTR_MTIME (1 << 5)
#define FATTR_FH (1 << 6)
#define FATTR_ATIME_NOW (1 << 7)
#define FATTR_MTIME_NOW (1 << 8)
#define FATTR_LOCKOWNER (1 << 9)
#define FATTR_CTIME (1 << 10)
#define FATTR_KILL_SUIDGID (1 << 11)
/**
* Flags returned by the OPEN request
*
* FOPEN_DIRECT_IO: bypass page cache for this open file
* FOPEN_KEEP_CACHE: don't invalidate the data cache on open
* FOPEN_NONSEEKABLE: the file is not seekable
* FOPEN_CACHE_DIR: allow caching this directory
* FOPEN_STREAM: the file is stream-like (no file position at all)
* FOPEN_NOFLUSH: don't flush data cache on close (unless FUSE_WRITEBACK_CACHE)
* FOPEN_PARALLEL_DIRECT_WRITES: Allow concurrent direct writes on the same inode
* FOPEN_PASSTHROUGH: passthrough read/write io for this open file
*/
#define FOPEN_DIRECT_IO (1 << 0)
#define FOPEN_KEEP_CACHE (1 << 1)
#define FOPEN_NONSEEKABLE (1 << 2)
#define FOPEN_CACHE_DIR (1 << 3)
#define FOPEN_STREAM (1 << 4)
#define FOPEN_NOFLUSH (1 << 5)
#define FOPEN_PARALLEL_DIRECT_WRITES (1 << 6)
#define FOPEN_PASSTHROUGH (1 << 7)
/**
* INIT request/reply flags
*
* FUSE_ASYNC_READ: asynchronous read requests
* FUSE_POSIX_LOCKS: remote locking for POSIX file locks
* FUSE_FILE_OPS: kernel sends file handle for fstat, etc... (not yet supported)
* FUSE_ATOMIC_O_TRUNC: handles the O_TRUNC open flag in the filesystem
* FUSE_EXPORT_SUPPORT: filesystem handles lookups of "." and ".."
* FUSE_BIG_WRITES: filesystem can handle write size larger than 4kB
* FUSE_DONT_MASK: don't apply umask to file mode on create operations
* FUSE_SPLICE_WRITE: kernel supports splice write on the device
* FUSE_SPLICE_MOVE: kernel supports splice move on the device
* FUSE_SPLICE_READ: kernel supports splice read on the device
* FUSE_FLOCK_LOCKS: remote locking for BSD style file locks
* FUSE_HAS_IOCTL_DIR: kernel supports ioctl on directories
* FUSE_AUTO_INVAL_DATA: automatically invalidate cached pages
* FUSE_DO_READDIRPLUS: do READDIRPLUS (READDIR+LOOKUP in one)
* FUSE_READDIRPLUS_AUTO: adaptive readdirplus
* FUSE_ASYNC_DIO: asynchronous direct I/O submission
* FUSE_WRITEBACK_CACHE: use writeback cache for buffered writes
* FUSE_NO_OPEN_SUPPORT: kernel supports zero-message opens
* FUSE_PARALLEL_DIROPS: allow parallel lookups and readdir
* FUSE_HANDLE_KILLPRIV: fs handles killing suid/sgid/cap on write/chown/trunc
* FUSE_POSIX_ACL: filesystem supports posix acls
* FUSE_ABORT_ERROR: reading the device after abort returns ECONNABORTED
* FUSE_MAX_PAGES: init_out.max_pages contains the max number of req pages
* FUSE_CACHE_SYMLINKS: cache READLINK responses
* FUSE_NO_OPENDIR_SUPPORT: kernel supports zero-message opendir
* FUSE_EXPLICIT_INVAL_DATA: only invalidate cached pages on explicit request
* FUSE_MAP_ALIGNMENT: init_out.map_alignment contains log2(byte alignment) for
* foffset and moffset fields in struct
* fuse_setupmapping_out and fuse_removemapping_one.
* FUSE_SUBMOUNTS: kernel supports auto-mounting directory submounts
* FUSE_HANDLE_KILLPRIV_V2: fs kills suid/sgid/cap on write/chown/trunc.
* Upon write/truncate suid/sgid is only killed if caller
* does not have CAP_FSETID. Additionally upon
* write/truncate sgid is killed only if file has group
* execute permission. (Same as Linux VFS behavior).
* FUSE_SETXATTR_EXT: Server supports extended struct fuse_setxattr_in
* FUSE_INIT_EXT: extended fuse_init_in request
* FUSE_INIT_RESERVED: reserved, do not use
* FUSE_SECURITY_CTX: add security context to create, mkdir, symlink, and
* mknod
* FUSE_HAS_INODE_DAX: use per inode DAX
* FUSE_CREATE_SUPP_GROUP: add supplementary group info to create, mkdir,
* symlink and mknod (single group that matches parent)
* FUSE_HAS_EXPIRE_ONLY: kernel supports expiry-only entry invalidation
* FUSE_DIRECT_IO_ALLOW_MMAP: allow shared mmap in FOPEN_DIRECT_IO mode.
* FUSE_NO_EXPORT_SUPPORT: explicitly disable export support
* FUSE_HAS_RESEND: kernel supports resending pending requests, and the high bit
* of the request ID indicates resend requests
* FUSE_ALLOW_IDMAP: allow creation of idmapped mounts
* FUSE_OVER_IO_URING: Indicate that client supports io-uring
* FUSE_REQUEST_TIMEOUT: kernel supports timing out requests.
* init_out.request_timeout contains the timeout (in secs)
*/
#define FUSE_ASYNC_READ (1 << 0)
#define FUSE_POSIX_LOCKS (1 << 1)
#define FUSE_FILE_OPS (1 << 2)
#define FUSE_ATOMIC_O_TRUNC (1 << 3)
#define FUSE_EXPORT_SUPPORT (1 << 4)
#define FUSE_BIG_WRITES (1 << 5)
#define FUSE_DONT_MASK (1 << 6)
#define FUSE_SPLICE_WRITE (1 << 7)
#define FUSE_SPLICE_MOVE (1 << 8)
#define FUSE_SPLICE_READ (1 << 9)
#define FUSE_FLOCK_LOCKS (1 << 10)
#define FUSE_HAS_IOCTL_DIR (1 << 11)
#define FUSE_AUTO_INVAL_DATA (1 << 12)
#define FUSE_DO_READDIRPLUS (1 << 13)
#define FUSE_READDIRPLUS_AUTO (1 << 14)
#define FUSE_ASYNC_DIO (1 << 15)
#define FUSE_WRITEBACK_CACHE (1 << 16)
#define FUSE_NO_OPEN_SUPPORT (1 << 17)
#define FUSE_PARALLEL_DIROPS (1 << 18)
#define FUSE_HANDLE_KILLPRIV (1 << 19)
#define FUSE_POSIX_ACL (1 << 20)
#define FUSE_ABORT_ERROR (1 << 21)
#define FUSE_MAX_PAGES (1 << 22)
#define FUSE_CACHE_SYMLINKS (1 << 23)
#define FUSE_NO_OPENDIR_SUPPORT (1 << 24)
#define FUSE_EXPLICIT_INVAL_DATA (1 << 25)
#define FUSE_MAP_ALIGNMENT (1 << 26)
#define FUSE_SUBMOUNTS (1 << 27)
#define FUSE_HANDLE_KILLPRIV_V2 (1 << 28)
#define FUSE_SETXATTR_EXT (1 << 29)
#define FUSE_INIT_EXT (1 << 30)
#define FUSE_INIT_RESERVED (1 << 31)
/* bits 32..63 get shifted down 32 bits into the flags2 field */
#define FUSE_SECURITY_CTX (1ULL << 32)
#define FUSE_HAS_INODE_DAX (1ULL << 33)
#define FUSE_CREATE_SUPP_GROUP (1ULL << 34)
#define FUSE_HAS_EXPIRE_ONLY (1ULL << 35)
#define FUSE_DIRECT_IO_ALLOW_MMAP (1ULL << 36)
#define FUSE_PASSTHROUGH (1ULL << 37)
#define FUSE_NO_EXPORT_SUPPORT (1ULL << 38)
#define FUSE_HAS_RESEND (1ULL << 39)
/* Obsolete alias for FUSE_DIRECT_IO_ALLOW_MMAP */
#define FUSE_DIRECT_IO_RELAX FUSE_DIRECT_IO_ALLOW_MMAP
#define FUSE_ALLOW_IDMAP (1ULL << 40)
#define FUSE_OVER_IO_URING (1ULL << 41)
#define FUSE_REQUEST_TIMEOUT (1ULL << 42)
/**
* CUSE INIT request/reply flags
*
* CUSE_UNRESTRICTED_IOCTL: use unrestricted ioctl
*/
#define CUSE_UNRESTRICTED_IOCTL (1 << 0)
/**
* Release flags
*/
#define FUSE_RELEASE_FLUSH (1 << 0)
#define FUSE_RELEASE_FLOCK_UNLOCK (1 << 1)
/**
* Getattr flags
*/
#define FUSE_GETATTR_FH (1 << 0)
/**
* Lock flags
*/
#define FUSE_LK_FLOCK (1 << 0)
/**
* WRITE flags
*
* FUSE_WRITE_CACHE: delayed write from page cache, file handle is guessed
* FUSE_WRITE_LOCKOWNER: lock_owner field is valid
* FUSE_WRITE_KILL_SUIDGID: kill suid and sgid bits
*/
#define FUSE_WRITE_CACHE (1 << 0)
#define FUSE_WRITE_LOCKOWNER (1 << 1)
#define FUSE_WRITE_KILL_SUIDGID (1 << 2)
/* Obsolete alias; this flag implies killing suid/sgid only. */
#define FUSE_WRITE_KILL_PRIV FUSE_WRITE_KILL_SUIDGID
/**
* Read flags
*/
#define FUSE_READ_LOCKOWNER (1 << 1)
/**
* Ioctl flags
*
* FUSE_IOCTL_COMPAT: 32bit compat ioctl on 64bit machine
* FUSE_IOCTL_UNRESTRICTED: not restricted to well-formed ioctls, retry allowed
* FUSE_IOCTL_RETRY: retry with new iovecs
* FUSE_IOCTL_32BIT: 32bit ioctl
* FUSE_IOCTL_DIR: is a directory
* FUSE_IOCTL_COMPAT_X32: x32 compat ioctl on 64bit machine (64bit time_t)
*
* FUSE_IOCTL_MAX_IOV: maximum of in_iovecs + out_iovecs
*/
#define FUSE_IOCTL_COMPAT (1 << 0)
#define FUSE_IOCTL_UNRESTRICTED (1 << 1)
#define FUSE_IOCTL_RETRY (1 << 2)
#define FUSE_IOCTL_32BIT (1 << 3)
#define FUSE_IOCTL_DIR (1 << 4)
#define FUSE_IOCTL_COMPAT_X32 (1 << 5)
#define FUSE_IOCTL_MAX_IOV 256
/**
* Poll flags
*
* FUSE_POLL_SCHEDULE_NOTIFY: request poll notify
*/
#define FUSE_POLL_SCHEDULE_NOTIFY (1 << 0)
/**
* Fsync flags
*
* FUSE_FSYNC_FDATASYNC: Sync data only, not metadata
*/
#define FUSE_FSYNC_FDATASYNC (1 << 0)
/**
* fuse_attr flags
*
* FUSE_ATTR_SUBMOUNT: Object is a submount root
* FUSE_ATTR_DAX: Enable DAX for this file in per inode DAX mode
*/
#define FUSE_ATTR_SUBMOUNT (1 << 0)
#define FUSE_ATTR_DAX (1 << 1)
/**
* Open flags
* FUSE_OPEN_KILL_SUIDGID: Kill suid and sgid if executable
*/
#define FUSE_OPEN_KILL_SUIDGID (1 << 0)
/**
* setxattr flags
* FUSE_SETXATTR_ACL_KILL_SGID: Clear SGID when system.posix_acl_access is set
*/
#define FUSE_SETXATTR_ACL_KILL_SGID (1 << 0)
/**
* notify_inval_entry flags
* FUSE_EXPIRE_ONLY
*/
#define FUSE_EXPIRE_ONLY (1 << 0)
/**
* extension type
* FUSE_MAX_NR_SECCTX: maximum value of &fuse_secctx_header.nr_secctx
* FUSE_EXT_GROUPS: &fuse_supp_groups extension
*/
enum fuse_ext_type {
/* Types 0..31 are reserved for fuse_secctx_header */
FUSE_MAX_NR_SECCTX = 31,
FUSE_EXT_GROUPS = 32,
};
enum fuse_opcode {
FUSE_LOOKUP = 1,
FUSE_FORGET = 2, /* no reply */
FUSE_GETATTR = 3,
FUSE_SETATTR = 4,
FUSE_READLINK = 5,
FUSE_SYMLINK = 6,
FUSE_MKNOD = 8,
FUSE_MKDIR = 9,
FUSE_UNLINK = 10,
FUSE_RMDIR = 11,
FUSE_RENAME = 12,
FUSE_LINK = 13,
FUSE_OPEN = 14,
FUSE_READ = 15,
FUSE_WRITE = 16,
FUSE_STATFS = 17,
FUSE_RELEASE = 18,
FUSE_FSYNC = 20,
FUSE_SETXATTR = 21,
FUSE_GETXATTR = 22,
FUSE_LISTXATTR = 23,
FUSE_REMOVEXATTR = 24,
FUSE_FLUSH = 25,
FUSE_INIT = 26,
FUSE_OPENDIR = 27,
FUSE_READDIR = 28,
FUSE_RELEASEDIR = 29,
FUSE_FSYNCDIR = 30,
FUSE_GETLK = 31,
FUSE_SETLK = 32,
FUSE_SETLKW = 33,
FUSE_ACCESS = 34,
FUSE_CREATE = 35,
FUSE_INTERRUPT = 36,
FUSE_BMAP = 37,
FUSE_DESTROY = 38,
FUSE_IOCTL = 39,
FUSE_POLL = 40,
FUSE_NOTIFY_REPLY = 41,
FUSE_BATCH_FORGET = 42,
FUSE_FALLOCATE = 43,
FUSE_READDIRPLUS = 44,
FUSE_RENAME2 = 45,
FUSE_LSEEK = 46,
FUSE_COPY_FILE_RANGE = 47,
FUSE_SETUPMAPPING = 48,
FUSE_REMOVEMAPPING = 49,
FUSE_SYNCFS = 50,
FUSE_TMPFILE = 51,
FUSE_STATX = 52,
FUSE_COPY_FILE_RANGE_64 = 53,
/* CUSE specific operations */
CUSE_INIT = 4096,
/* Reserved opcodes: helpful to detect structure endian-ness */
CUSE_INIT_BSWAP_RESERVED = 1048576, /* CUSE_INIT << 8 */
FUSE_INIT_BSWAP_RESERVED = 436207616, /* FUSE_INIT << 24 */
};
enum fuse_notify_code {
FUSE_NOTIFY_POLL = 1,
FUSE_NOTIFY_INVAL_INODE = 2,
FUSE_NOTIFY_INVAL_ENTRY = 3,
FUSE_NOTIFY_STORE = 4,
FUSE_NOTIFY_RETRIEVE = 5,
FUSE_NOTIFY_DELETE = 6,
FUSE_NOTIFY_RESEND = 7,
FUSE_NOTIFY_INC_EPOCH = 8,
FUSE_NOTIFY_PRUNE = 9,
};
/* The read buffer is required to be at least 8k, but may be much larger */
#define FUSE_MIN_READ_BUFFER 8192
#define FUSE_COMPAT_ENTRY_OUT_SIZE 120
struct fuse_entry_out {
fuse_u64 nodeid; /* Inode ID */
fuse_u64 generation; /* Inode generation: nodeid:gen must
be unique for the fs's lifetime */
fuse_u64 entry_valid; /* Cache timeout for the name */
fuse_u64 attr_valid; /* Cache timeout for the attributes */
fuse_u32 entry_valid_nsec;
fuse_u32 attr_valid_nsec;
struct fuse_attr attr;
};
struct fuse_forget_in {
fuse_u64 nlookup;
};
struct fuse_forget_one {
fuse_u64 nodeid;
fuse_u64 nlookup;
};
struct fuse_batch_forget_in {
fuse_u32 count;
fuse_u32 dummy;
};
struct fuse_getattr_in {
fuse_u32 getattr_flags;
fuse_u32 dummy;
fuse_u64 fh;
};
#define FUSE_COMPAT_ATTR_OUT_SIZE 96
struct fuse_attr_out {
fuse_u64 attr_valid; /* Cache timeout for the attributes */
fuse_u32 attr_valid_nsec;
fuse_u32 dummy;
struct fuse_attr attr;
};
struct fuse_statx_in {
fuse_u32 getattr_flags;
fuse_u32 reserved;
fuse_u64 fh;
fuse_u32 sx_flags;
fuse_u32 sx_mask;
};
struct fuse_statx_out {
fuse_u64 attr_valid; /* Cache timeout for the attributes */
fuse_u32 attr_valid_nsec;
fuse_u32 flags;
fuse_u64 spare[2];
struct fuse_statx stat;
};
#define FUSE_COMPAT_MKNOD_IN_SIZE 8
struct fuse_mknod_in {
fuse_u32 mode;
fuse_u32 rdev;
fuse_u32 umask;
fuse_u32 padding;
};
struct fuse_mkdir_in {
fuse_u32 mode;
fuse_u32 umask;
};
struct fuse_rename_in {
fuse_u64 newdir;
};
struct fuse_rename2_in {
fuse_u64 newdir;
fuse_u32 flags;
fuse_u32 padding;
};
struct fuse_link_in {
fuse_u64 oldnodeid;
};
struct fuse_setattr_in {
fuse_u32 valid;
fuse_u32 padding;
fuse_u64 fh;
fuse_u64 size;
fuse_u64 lock_owner;
fuse_u64 atime;
fuse_u64 mtime;
fuse_u64 ctime;
fuse_u32 atimensec;
fuse_u32 mtimensec;
fuse_u32 ctimensec;
fuse_u32 mode;
fuse_u32 unused4;
fuse_u32 uid;
fuse_u32 gid;
fuse_u32 unused5;
};
struct fuse_open_in {
fuse_u32 flags;
fuse_u32 open_flags; /* FUSE_OPEN_... */
};
struct fuse_create_in {
fuse_u32 flags;
fuse_u32 mode;
fuse_u32 umask;
fuse_u32 open_flags; /* FUSE_OPEN_... */
};
struct fuse_open_out {
fuse_u64 fh;
fuse_u32 open_flags;
fuse_s32 backing_id;
};
struct fuse_release_in {
fuse_u64 fh;
fuse_u32 flags;
fuse_u32 release_flags;
fuse_u64 lock_owner;
};
struct fuse_flush_in {
fuse_u64 fh;
fuse_u32 unused;
fuse_u32 padding;
fuse_u64 lock_owner;
};
struct fuse_read_in {
fuse_u64 fh;
fuse_u64 offset;
fuse_u32 size;
fuse_u32 read_flags;
fuse_u64 lock_owner;
fuse_u32 flags;
fuse_u32 padding;
};
#define FUSE_COMPAT_WRITE_IN_SIZE 24
struct fuse_write_in {
fuse_u64 fh;
fuse_u64 offset;
fuse_u32 size;
fuse_u32 write_flags;
fuse_u64 lock_owner;
fuse_u32 flags;
fuse_u32 padding;
};
struct fuse_write_out {
fuse_u32 size;
fuse_u32 padding;
};
#define FUSE_COMPAT_STATFS_SIZE 48
struct fuse_statfs_out {
struct fuse_kstatfs st;
};
struct fuse_fsync_in {
fuse_u64 fh;
fuse_u32 fsync_flags;
fuse_u32 padding;
};
#define FUSE_COMPAT_SETXATTR_IN_SIZE 8
struct fuse_setxattr_in {
fuse_u32 size;
fuse_u32 flags;
fuse_u32 setxattr_flags;
fuse_u32 padding;
};
struct fuse_getxattr_in {
fuse_u32 size;
fuse_u32 padding;
};
struct fuse_getxattr_out {
fuse_u32 size;
fuse_u32 padding;
};
struct fuse_lk_in {
fuse_u64 fh;
fuse_u64 owner;
struct fuse_file_lock lk;
fuse_u32 lk_flags;
fuse_u32 padding;
};
struct fuse_lk_out {
struct fuse_file_lock lk;
};
struct fuse_access_in {
fuse_u32 mask;
fuse_u32 padding;
};
struct fuse_init_in {
fuse_u32 major;
fuse_u32 minor;
fuse_u32 max_readahead;
fuse_u32 flags;
fuse_u32 flags2;
fuse_u32 unused[11];
};
#define FUSE_COMPAT_INIT_OUT_SIZE 8
#define FUSE_COMPAT_22_INIT_OUT_SIZE 24
struct fuse_init_out {
fuse_u32 major;
fuse_u32 minor;
fuse_u32 max_readahead;
fuse_u32 flags;
fuse_u16 max_background;
fuse_u16 congestion_threshold;
fuse_u32 max_write;
fuse_u32 time_gran;
fuse_u16 max_pages;
fuse_u16 map_alignment;
fuse_u32 flags2;
fuse_u32 max_stack_depth;
fuse_u16 request_timeout;
fuse_u16 unused[11];
};
#define CUSE_INIT_INFO_MAX 4096
struct cuse_init_in {
fuse_u32 major;
fuse_u32 minor;
fuse_u32 unused;
fuse_u32 flags;
};
struct cuse_init_out {
fuse_u32 major;
fuse_u32 minor;
fuse_u32 unused;
fuse_u32 flags;
fuse_u32 max_read;
fuse_u32 max_write;
fuse_u32 dev_major; /* chardev major */
fuse_u32 dev_minor; /* chardev minor */
fuse_u32 spare[10];
};
struct fuse_interrupt_in {
fuse_u64 unique;
};
struct fuse_bmap_in {
fuse_u64 block;
fuse_u32 blocksize;
fuse_u32 padding;
};
struct fuse_bmap_out {
fuse_u64 block;
};
struct fuse_ioctl_in {
fuse_u64 fh;
fuse_u32 flags;
fuse_u32 cmd;
fuse_u64 arg;
fuse_u32 in_size;
fuse_u32 out_size;
};
struct fuse_ioctl_iovec {
fuse_u64 base;
fuse_u64 len;
};
struct fuse_ioctl_out {
fuse_s32 result;
fuse_u32 flags;
fuse_u32 in_iovs;
fuse_u32 out_iovs;
};
struct fuse_poll_in {
fuse_u64 fh;
fuse_u64 kh;
fuse_u32 flags;
fuse_u32 events;
};
struct fuse_poll_out {
fuse_u32 revents;
fuse_u32 padding;
};
struct fuse_notify_poll_wakeup_out {
fuse_u64 kh;
};
struct fuse_fallocate_in {
fuse_u64 fh;
fuse_u64 offset;
fuse_u64 length;
fuse_u32 mode;
fuse_u32 padding;
};
/**
* FUSE request unique ID flag
*
* Indicates whether this is a resend request. The receiver should handle this
* request accordingly.
*/
#define FUSE_UNIQUE_RESEND (1ULL << 63)
/**
* This value will be set by the kernel to
* (struct fuse_in_header).{uid,gid} fields in
* case when:
* - fuse daemon enabled FUSE_ALLOW_IDMAP
* - idmapping information is not available and uid/gid
* can not be mapped in accordance with an idmapping.
*
* Note: an idmapping information always available
* for inode creation operations like:
* FUSE_MKNOD, FUSE_SYMLINK, FUSE_MKDIR, FUSE_TMPFILE,
* FUSE_CREATE and FUSE_RENAME2 (with RENAME_WHITEOUT).
*/
#define FUSE_INVALID_UIDGID ((fuse_u32)(-1))
struct fuse_in_header {
fuse_u32 len;
fuse_u32 opcode;
fuse_u64 unique;
fuse_u64 nodeid;
fuse_u32 uid;
fuse_u32 gid;
fuse_u32 pid;
fuse_u16 total_extlen; /* length of extensions in 8byte units */
fuse_u16 padding;
};
struct fuse_out_header {
fuse_u32 len;
fuse_s32 error;
fuse_u64 unique;
};
struct fuse_dirent {
fuse_u64 ino;
fuse_u64 off;
fuse_u32 namelen;
fuse_u32 type;
char name[];
};
/* Align variable length records to 64bit boundary */
#define FUSE_REC_ALIGN(x) \
(((x) + sizeof(fuse_u64) - 1) & ~(sizeof(fuse_u64) - 1))
#define FUSE_NAME_OFFSET offsetof(struct fuse_dirent, name)
#define FUSE_DIRENT_ALIGN(x) FUSE_REC_ALIGN(x)
#define FUSE_DIRENT_SIZE(d) \
FUSE_DIRENT_ALIGN(FUSE_NAME_OFFSET + (d)->namelen)
struct fuse_direntplus {
struct fuse_entry_out entry_out;
struct fuse_dirent dirent;
};
#define FUSE_NAME_OFFSET_DIRENTPLUS \
offsetof(struct fuse_direntplus, dirent.name)
#define FUSE_DIRENTPLUS_SIZE(d) \
FUSE_DIRENT_ALIGN(FUSE_NAME_OFFSET_DIRENTPLUS + (d)->dirent.namelen)
struct fuse_notify_inval_inode_out {
fuse_u64 ino;
fuse_s64 off;
fuse_s64 len;
};
struct fuse_notify_inval_entry_out {
fuse_u64 parent;
fuse_u32 namelen;
fuse_u32 flags;
};
struct fuse_notify_delete_out {
fuse_u64 parent;
fuse_u64 child;
fuse_u32 namelen;
fuse_u32 padding;
};
struct fuse_notify_store_out {
fuse_u64 nodeid;
fuse_u64 offset;
fuse_u32 size;
fuse_u32 padding;
};
struct fuse_notify_retrieve_out {
fuse_u64 notify_unique;
fuse_u64 nodeid;
fuse_u64 offset;
fuse_u32 size;
fuse_u32 padding;
};
/* Matches the size of fuse_write_in */
struct fuse_notify_retrieve_in {
fuse_u64 dummy1;
fuse_u64 offset;
fuse_u32 size;
fuse_u32 dummy2;
fuse_u64 dummy3;
fuse_u64 dummy4;
};
struct fuse_notify_prune_out {
fuse_u32 count;
fuse_u32 padding;
fuse_u64 spare;
};
struct fuse_backing_map {
fuse_s32 fd;
fuse_u32 flags;
fuse_u64 padding;
};
/* Device ioctls: */
#define FUSE_DEV_IOC_MAGIC 229
#define FUSE_DEV_IOC_CLONE _IOR(FUSE_DEV_IOC_MAGIC, 0, fuse_u32)
#define FUSE_DEV_IOC_BACKING_OPEN _IOW(FUSE_DEV_IOC_MAGIC, 1, \
struct fuse_backing_map)
#define FUSE_DEV_IOC_BACKING_CLOSE _IOW(FUSE_DEV_IOC_MAGIC, 2, fuse_u32)
#define FUSE_DEV_IOC_SYNC_INIT _IO(FUSE_DEV_IOC_MAGIC, 3)
struct fuse_lseek_in {
fuse_u64 fh;
fuse_u64 offset;
fuse_u32 whence;
fuse_u32 padding;
};
struct fuse_lseek_out {
fuse_u64 offset;
};
struct fuse_copy_file_range_in {
fuse_u64 fh_in;
fuse_u64 off_in;
fuse_u64 nodeid_out;
fuse_u64 fh_out;
fuse_u64 off_out;
fuse_u64 len;
fuse_u64 flags;
};
/* For FUSE_COPY_FILE_RANGE_64 */
struct fuse_copy_file_range_out {
fuse_u64 bytes_copied;
};
#define FUSE_SETUPMAPPING_FLAG_WRITE (1ull << 0)
#define FUSE_SETUPMAPPING_FLAG_READ (1ull << 1)
struct fuse_setupmapping_in {
/* An already open handle */
fuse_u64 fh;
/* Offset into the file to start the mapping */
fuse_u64 foffset;
/* Length of mapping required */
fuse_u64 len;
/* Flags, FUSE_SETUPMAPPING_FLAG_* */
fuse_u64 flags;
/* Offset in Memory Window */
fuse_u64 moffset;
};
struct fuse_removemapping_in {
/* number of fuse_removemapping_one follows */
fuse_u32 count;
};
struct fuse_removemapping_one {
/* Offset into the dax window start the unmapping */
fuse_u64 moffset;
/* Length of mapping required */
fuse_u64 len;
};
#define FUSE_REMOVEMAPPING_MAX_ENTRY \
(PAGE_SIZE / sizeof(struct fuse_removemapping_one))
struct fuse_syncfs_in {
fuse_u64 padding;
};
/*
* For each security context, send fuse_secctx with size of security context
* fuse_secctx will be followed by security context name and this in turn
* will be followed by actual context label.
* fuse_secctx, name, context
*/
struct fuse_secctx {
fuse_u32 size;
fuse_u32 padding;
};
/*
* Contains the information about how many fuse_secctx structures are being
* sent and what's the total size of all security contexts (including
* size of fuse_secctx_header).
*
*/
struct fuse_secctx_header {
fuse_u32 size;
fuse_u32 nr_secctx;
};
/**
* struct fuse_ext_header - extension header
* @size: total size of this extension including this header
* @type: type of extension
*
* This is made compatible with fuse_secctx_header by using type values >
* FUSE_MAX_NR_SECCTX
*/
struct fuse_ext_header {
fuse_u32 size;
fuse_u32 type;
};
/**
* struct fuse_supp_groups - Supplementary group extension
* @nr_groups: number of supplementary groups
* @groups: flexible array of group IDs
*/
struct fuse_supp_groups {
fuse_u32 nr_groups;
fuse_u32 groups[];
};
/**
* Size of the ring buffer header
*/
#define FUSE_URING_IN_OUT_HEADER_SZ 128
#define FUSE_URING_OP_IN_OUT_SZ 128
/* Used as part of the fuse_uring_req_header */
struct fuse_uring_ent_in_out {
fuse_u64 flags;
/*
* commit ID to be used in a reply to a ring request (see also
* struct fuse_uring_cmd_req)
*/
fuse_u64 commit_id;
/* size of user payload buffer */
fuse_u32 payload_sz;
fuse_u32 padding;
fuse_u64 reserved;
};
/**
* Header for all fuse-io-uring requests
*/
struct fuse_uring_req_header {
/* struct fuse_in_header / struct fuse_out_header */
char in_out[FUSE_URING_IN_OUT_HEADER_SZ];
/* per op code header */
char op_in[FUSE_URING_OP_IN_OUT_SZ];
struct fuse_uring_ent_in_out ring_ent_in_out;
};
/**
* sqe commands to the kernel
*/
enum fuse_uring_cmd {
FUSE_IO_URING_CMD_INVALID = 0,
/* register the request buffer and fetch a fuse request */
FUSE_IO_URING_CMD_REGISTER = 1,
/* commit fuse request result and fetch next request */
FUSE_IO_URING_CMD_COMMIT_AND_FETCH = 2,
};
/**
* In the 80B command area of the SQE.
*/
struct fuse_uring_cmd_req {
fuse_u64 flags;
/* entry identifier for commits */
fuse_u64 commit_id;
/* queue the command is for (queue index) */
fuse_u16 qid;
fuse_u8 padding[6];
};
#endif /* _LINUX_FUSE_H */
^ permalink raw reply [flat|nested] 21+ messages in thread
* Re: [PATCH v2] fuse: uapi: use UAPI types
2026-01-02 22:27 ` Bernd Schubert
2026-01-03 12:44 ` Bernd Schubert
@ 2026-01-03 14:10 ` David Laight
2026-01-03 16:47 ` Bernd Schubert
1 sibling, 1 reply; 21+ messages in thread
From: David Laight @ 2026-01-03 14:10 UTC (permalink / raw)
To: Bernd Schubert
Cc: Thomas Weißschuh, Miklos Szeredi, linux-fsdevel,
linux-kernel, Arnd Bergmann
On Fri, 2 Jan 2026 23:27:16 +0100
Bernd Schubert <bernd@bsbernd.com> wrote:
> On 12/30/25 13:10, Thomas Weißschuh wrote:
> > Using libc types and headers from the UAPI headers is problematic as it
> > introduces a dependency on a full C toolchain.
> >
> > Use the fixed-width integer types provided by the UAPI headers instead.
> > To keep compatibility with non-Linux platforms, add a stdint.h fallback.
> >
> > Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
> > ---
> > Changes in v2:
> > - Fix structure member alignments
> > - Keep compatibility with non-Linux platforms
> > - Link to v1: https://lore.kernel.org/r/20251222-uapi-fuse-v1-1-85a61b87baa0@linutronix.de
> > ---
> > include/uapi/linux/fuse.h | 626 +++++++++++++++++++++++-----------------------
> > 1 file changed, 319 insertions(+), 307 deletions(-)
>
> I tested this and it breaks libfuse compilation
>
> https://github.com/libfuse/libfuse/pull/1410
>
> Any chance you could test libfuse compilation for v3? Easiest way is to
> copy it to <libfuse>/include/fuse_kernel.h and then create PR. That
> includes a BSD test.
>
>
> libfuse3.so.3.19.0.p/fuse_uring.c.o -c
> ../../../home/runner/work/libfuse/libfuse/lib/fuse_uring.c
> ../../../home/runner/work/libfuse/libfuse/lib/fuse_uring.c:197:5: error:
> format specifies type 'unsigned long' but the argument has type '__u64'
> (aka 'unsigned long long') [-Werror,-Wformat]
> 196 | fuse_log(FUSE_LOG_DEBUG, " unique: %" PRIu64
> ", result=%d\n",
> | ~~~~~~~~~
> 197 | out->unique, ent_in_out->payload_sz);
> | ^~~~~~~~~~~
> 1 error generated.
>
>
> I can certainly work it around in libfuse by adding a cast, IMHO,
> PRIu64 is the right format.
Or use 'unsigned long long' for the 64bit values and %llu for the format.
I'm pretty sure that works for all reasonable modern architectures.
You might still want to use the fuse_[us][8|16|32|64] names but they
can be defined directly as char/short/int/long long.
David
>
>
> Thanks,
> Bernd
>
^ permalink raw reply [flat|nested] 21+ messages in thread
* Re: [PATCH v2] fuse: uapi: use UAPI types
2026-01-03 14:10 ` David Laight
@ 2026-01-03 16:47 ` Bernd Schubert
0 siblings, 0 replies; 21+ messages in thread
From: Bernd Schubert @ 2026-01-03 16:47 UTC (permalink / raw)
To: David Laight
Cc: Thomas Weißschuh, Miklos Szeredi, linux-fsdevel,
linux-kernel, Arnd Bergmann
On 1/3/26 15:10, David Laight wrote:
> On Fri, 2 Jan 2026 23:27:16 +0100
> Bernd Schubert <bernd@bsbernd.com> wrote:
>
>> On 12/30/25 13:10, Thomas Weißschuh wrote:
>>> Using libc types and headers from the UAPI headers is problematic as it
>>> introduces a dependency on a full C toolchain.
>>>
>>> Use the fixed-width integer types provided by the UAPI headers instead.
>>> To keep compatibility with non-Linux platforms, add a stdint.h fallback.
>>>
>>> Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
>>> ---
>>> Changes in v2:
>>> - Fix structure member alignments
>>> - Keep compatibility with non-Linux platforms
>>> - Link to v1: https://lore.kernel.org/r/20251222-uapi-fuse-v1-1-85a61b87baa0@linutronix.de
>>> ---
>>> include/uapi/linux/fuse.h | 626 +++++++++++++++++++++++-----------------------
>>> 1 file changed, 319 insertions(+), 307 deletions(-)
>>
>> I tested this and it breaks libfuse compilation
>>
>> https://github.com/libfuse/libfuse/pull/1410
>>
>> Any chance you could test libfuse compilation for v3? Easiest way is to
>> copy it to <libfuse>/include/fuse_kernel.h and then create PR. That
>> includes a BSD test.
>>
>>
>> libfuse3.so.3.19.0.p/fuse_uring.c.o -c
>> ../../../home/runner/work/libfuse/libfuse/lib/fuse_uring.c
>> ../../../home/runner/work/libfuse/libfuse/lib/fuse_uring.c:197:5: error:
>> format specifies type 'unsigned long' but the argument has type '__u64'
>> (aka 'unsigned long long') [-Werror,-Wformat]
>> 196 | fuse_log(FUSE_LOG_DEBUG, " unique: %" PRIu64
>> ", result=%d\n",
>> | ~~~~~~~~~
>> 197 | out->unique, ent_in_out->payload_sz);
>> | ^~~~~~~~~~~
>> 1 error generated.
>>
>>
>> I can certainly work it around in libfuse by adding a cast, IMHO,
>> PRIu64 is the right format.
>
> Or use 'unsigned long long' for the 64bit values and %llu for the format.
> I'm pretty sure that works for all reasonable modern architectures.
>
> You might still want to use the fuse_[us][8|16|32|64] names but they
> can be defined directly as char/short/int/long long.
Well, what speaks against to it like I have done? A few more lines of
code, but even unlikely arch issues are excluded.
Thanks,
Bernd
^ permalink raw reply [flat|nested] 21+ messages in thread
* Re: [PATCH v2] fuse: uapi: use UAPI types
2026-01-03 12:44 ` Bernd Schubert
@ 2026-01-05 8:40 ` Thomas Weißschuh
2026-01-05 8:50 ` Bernd Schubert
0 siblings, 1 reply; 21+ messages in thread
From: Thomas Weißschuh @ 2026-01-05 8:40 UTC (permalink / raw)
To: Bernd Schubert; +Cc: Miklos Szeredi, linux-fsdevel, linux-kernel, Arnd Bergmann
On Sat, Jan 03, 2026 at 01:44:49PM +0100, Bernd Schubert wrote:
>
>
> On 1/2/26 23:27, Bernd Schubert wrote:
> >
> >
> > On 12/30/25 13:10, Thomas Weißschuh wrote:
> >> Using libc types and headers from the UAPI headers is problematic as it
> >> introduces a dependency on a full C toolchain.
> >>
> >> Use the fixed-width integer types provided by the UAPI headers instead.
> >> To keep compatibility with non-Linux platforms, add a stdint.h fallback.
> >>
> >> Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
> >> ---
> >> Changes in v2:
> >> - Fix structure member alignments
> >> - Keep compatibility with non-Linux platforms
> >> - Link to v1: https://lore.kernel.org/r/20251222-uapi-fuse-v1-1-85a61b87baa0@linutronix.de
> >> ---
> >> include/uapi/linux/fuse.h | 626 +++++++++++++++++++++++-----------------------
> >> 1 file changed, 319 insertions(+), 307 deletions(-)
> >
> > I tested this and it breaks libfuse compilation
> >
> > https://github.com/libfuse/libfuse/pull/1410
> >
> > Any chance you could test libfuse compilation for v3? Easiest way is to
> > copy it to <libfuse>/include/fuse_kernel.h and then create PR. That
> > includes a BSD test.
Ack.
> > libfuse3.so.3.19.0.p/fuse_uring.c.o -c
> > ../../../home/runner/work/libfuse/libfuse/lib/fuse_uring.c
> > ../../../home/runner/work/libfuse/libfuse/lib/fuse_uring.c:197:5: error:
> > format specifies type 'unsigned long' but the argument has type '__u64'
> > (aka 'unsigned long long') [-Werror,-Wformat]
> > 196 | fuse_log(FUSE_LOG_DEBUG, " unique: %" PRIu64
> > ", result=%d\n",
> > | ~~~~~~~~~
> > 197 | out->unique, ent_in_out->payload_sz);
> > | ^~~~~~~~~~~
> > 1 error generated.
> >
> >
> > I can certainly work it around in libfuse by adding a cast, IMHO,
> > PRIu64 is the right format.
PRIu64 is indeed the right format for uint64_t. Unfortunately not necessarily
for __u64. As the vast majority of the UAPI headers to use the UAPI types,
adding a cast in this case is already necessary for most UAPI users.
> I think what would work is the attached version. Short interesting part
>
> #if defined(__KERNEL__)
> #include <linux/types.h>
> typedef __u8 fuse_u8;
> typedef __u16 fuse_u16;
> typedef __u32 fuse_u32;
> typedef __u64 fuse_u64;
> typedef __s8 fuse_s8;
> typedef __s16 fuse_s16;
> typedef __s32 fuse_s32;
> typedef __s64 fuse_s64;
> #else
> #include <stdint.h>
> typedef uint8_t fuse_u8;
> typedef uint16_t fuse_u16;
> typedef uint32_t fuse_u32;
> typedef uint64_t fuse_u64;
> typedef int8_t fuse_s8;
> typedef int16_t fuse_s16;
> typedef int32_t fuse_s32;
> typedef int64_t fuse_s64;
> #endif
Unfortunately this is equivalent to the status quo.
It contains a dependency on the libc header stdint.h when used from userspace.
IMO the best way forward is to use the v2 patch and add a cast in fuse_uring.c.
Thomas
^ permalink raw reply [flat|nested] 21+ messages in thread
* Re: [PATCH v2] fuse: uapi: use UAPI types
2026-01-05 8:40 ` Thomas Weißschuh
@ 2026-01-05 8:50 ` Bernd Schubert
2026-01-05 9:57 ` Thomas Weißschuh
2026-01-05 12:09 ` Arnd Bergmann
0 siblings, 2 replies; 21+ messages in thread
From: Bernd Schubert @ 2026-01-05 8:50 UTC (permalink / raw)
To: Thomas Weißschuh
Cc: Miklos Szeredi, linux-fsdevel, linux-kernel, Arnd Bergmann
On 1/5/26 09:40, Thomas Weißschuh wrote:
> On Sat, Jan 03, 2026 at 01:44:49PM +0100, Bernd Schubert wrote:
>>
>>
>> On 1/2/26 23:27, Bernd Schubert wrote:
>>>
>>>
>>> On 12/30/25 13:10, Thomas Weißschuh wrote:
>>>> Using libc types and headers from the UAPI headers is problematic as it
>>>> introduces a dependency on a full C toolchain.
>>>>
>>>> Use the fixed-width integer types provided by the UAPI headers instead.
>>>> To keep compatibility with non-Linux platforms, add a stdint.h fallback.
>>>>
>>>> Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
>>>> ---
>>>> Changes in v2:
>>>> - Fix structure member alignments
>>>> - Keep compatibility with non-Linux platforms
>>>> - Link to v1: https://lore.kernel.org/r/20251222-uapi-fuse-v1-1-85a61b87baa0@linutronix.de
>>>> ---
>>>> include/uapi/linux/fuse.h | 626 +++++++++++++++++++++++-----------------------
>>>> 1 file changed, 319 insertions(+), 307 deletions(-)
>>>
>>> I tested this and it breaks libfuse compilation
>>>
>>> https://github.com/libfuse/libfuse/pull/1410
>>>
>>> Any chance you could test libfuse compilation for v3? Easiest way is to
>>> copy it to <libfuse>/include/fuse_kernel.h and then create PR. That
>>> includes a BSD test.
>
> Ack.
>
>>> libfuse3.so.3.19.0.p/fuse_uring.c.o -c
>>> ../../../home/runner/work/libfuse/libfuse/lib/fuse_uring.c
>>> ../../../home/runner/work/libfuse/libfuse/lib/fuse_uring.c:197:5: error:
>>> format specifies type 'unsigned long' but the argument has type '__u64'
>>> (aka 'unsigned long long') [-Werror,-Wformat]
>>> 196 | fuse_log(FUSE_LOG_DEBUG, " unique: %" PRIu64
>>> ", result=%d\n",
>>> | ~~~~~~~~~
>>> 197 | out->unique, ent_in_out->payload_sz);
>>> | ^~~~~~~~~~~
>>> 1 error generated.
>>>
>>>
>>> I can certainly work it around in libfuse by adding a cast, IMHO,
>>> PRIu64 is the right format.
>
> PRIu64 is indeed the right format for uint64_t. Unfortunately not necessarily
> for __u64. As the vast majority of the UAPI headers to use the UAPI types,
> adding a cast in this case is already necessary for most UAPI users.
>
>> I think what would work is the attached version. Short interesting part
>>
>> #if defined(__KERNEL__)
>> #include <linux/types.h>
>> typedef __u8 fuse_u8;
>> typedef __u16 fuse_u16;
>> typedef __u32 fuse_u32;
>> typedef __u64 fuse_u64;
>> typedef __s8 fuse_s8;
>> typedef __s16 fuse_s16;
>> typedef __s32 fuse_s32;
>> typedef __s64 fuse_s64;
>> #else
>> #include <stdint.h>
>> typedef uint8_t fuse_u8;
>> typedef uint16_t fuse_u16;
>> typedef uint32_t fuse_u32;
>> typedef uint64_t fuse_u64;
>> typedef int8_t fuse_s8;
>> typedef int16_t fuse_s16;
>> typedef int32_t fuse_s32;
>> typedef int64_t fuse_s64;
>> #endif
>
> Unfortunately this is equivalent to the status quo.
> It contains a dependency on the libc header stdint.h when used from userspace.
>
> IMO the best way forward is to use the v2 patch and add a cast in fuse_uring.c.
libfuse is easy, but libfuse is just one library that might use/copy the
header. If libfuse breaks the others might as well.
Maybe you could explain your issue more detailed? I.e. how are you using
this include exactly?
Thanks,
Bernd
^ permalink raw reply [flat|nested] 21+ messages in thread
* Re: [PATCH v2] fuse: uapi: use UAPI types
2026-01-05 8:50 ` Bernd Schubert
@ 2026-01-05 9:57 ` Thomas Weißschuh
2026-01-05 12:09 ` Arnd Bergmann
1 sibling, 0 replies; 21+ messages in thread
From: Thomas Weißschuh @ 2026-01-05 9:57 UTC (permalink / raw)
To: Bernd Schubert; +Cc: Miklos Szeredi, linux-fsdevel, linux-kernel, Arnd Bergmann
On Mon, Jan 05, 2026 at 09:50:30AM +0100, Bernd Schubert wrote:
>
>
> On 1/5/26 09:40, Thomas Weißschuh wrote:
> > On Sat, Jan 03, 2026 at 01:44:49PM +0100, Bernd Schubert wrote:
> >>
> >>
> >> On 1/2/26 23:27, Bernd Schubert wrote:
> >>>
> >>>
> >>> On 12/30/25 13:10, Thomas Weißschuh wrote:
> >>>> Using libc types and headers from the UAPI headers is problematic as it
> >>>> introduces a dependency on a full C toolchain.
> >>>>
> >>>> Use the fixed-width integer types provided by the UAPI headers instead.
> >>>> To keep compatibility with non-Linux platforms, add a stdint.h fallback.
> >>>>
> >>>> Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
> >>>> ---
> >>>> Changes in v2:
> >>>> - Fix structure member alignments
> >>>> - Keep compatibility with non-Linux platforms
> >>>> - Link to v1: https://lore.kernel.org/r/20251222-uapi-fuse-v1-1-85a61b87baa0@linutronix.de
> >>>> ---
> >>>> include/uapi/linux/fuse.h | 626 +++++++++++++++++++++++-----------------------
> >>>> 1 file changed, 319 insertions(+), 307 deletions(-)
> >>>
> >>> I tested this and it breaks libfuse compilation
> >>>
> >>> https://github.com/libfuse/libfuse/pull/1410
> >>>
> >>> Any chance you could test libfuse compilation for v3? Easiest way is to
> >>> copy it to <libfuse>/include/fuse_kernel.h and then create PR. That
> >>> includes a BSD test.
> >
> > Ack.
> >
> >>> libfuse3.so.3.19.0.p/fuse_uring.c.o -c
> >>> ../../../home/runner/work/libfuse/libfuse/lib/fuse_uring.c
> >>> ../../../home/runner/work/libfuse/libfuse/lib/fuse_uring.c:197:5: error:
> >>> format specifies type 'unsigned long' but the argument has type '__u64'
> >>> (aka 'unsigned long long') [-Werror,-Wformat]
> >>> 196 | fuse_log(FUSE_LOG_DEBUG, " unique: %" PRIu64
> >>> ", result=%d\n",
> >>> | ~~~~~~~~~
> >>> 197 | out->unique, ent_in_out->payload_sz);
> >>> | ^~~~~~~~~~~
> >>> 1 error generated.
> >>>
> >>>
> >>> I can certainly work it around in libfuse by adding a cast, IMHO,
> >>> PRIu64 is the right format.
> >
> > PRIu64 is indeed the right format for uint64_t. Unfortunately not necessarily
> > for __u64. As the vast majority of the UAPI headers to use the UAPI types,
> > adding a cast in this case is already necessary for most UAPI users.
> >
> >> I think what would work is the attached version. Short interesting part
> >>
> >> #if defined(__KERNEL__)
> >> #include <linux/types.h>
> >> typedef __u8 fuse_u8;
> >> typedef __u16 fuse_u16;
> >> typedef __u32 fuse_u32;
> >> typedef __u64 fuse_u64;
> >> typedef __s8 fuse_s8;
> >> typedef __s16 fuse_s16;
> >> typedef __s32 fuse_s32;
> >> typedef __s64 fuse_s64;
> >> #else
> >> #include <stdint.h>
> >> typedef uint8_t fuse_u8;
> >> typedef uint16_t fuse_u16;
> >> typedef uint32_t fuse_u32;
> >> typedef uint64_t fuse_u64;
> >> typedef int8_t fuse_s8;
> >> typedef int16_t fuse_s16;
> >> typedef int32_t fuse_s32;
> >> typedef int64_t fuse_s64;
> >> #endif
> >
> > Unfortunately this is equivalent to the status quo.
> > It contains a dependency on the libc header stdint.h when used from userspace.
> >
> > IMO the best way forward is to use the v2 patch and add a cast in fuse_uring.c.
>
> libfuse is easy, but libfuse is just one library that might use/copy the
> header. If libfuse breaks the others might as well.
Yes, unfortunately.
> Maybe you could explain your issue more detailed? I.e. how are you using
> this include exactly?
I want the linux/fuse.h to work together with -nostdinc.
This has various advantages:
* It allows compilers for other languages to parse the C headers without
the dependency on a full toolchain.
* It enables the usage in other, non-libc based C environments.
* Together with [0], it allows the verification of the header for all
architectures. For example Arnd works on validating the UAPI against -Wpadded
which requires the header to be built for each architecture.
This affected me at [1] and now I'm trying to proactively avoid this issue in
other places and prevent its re-introduction.
[0] https://lore.kernel.org/lkml/20251223-uapi-nostdinc-v1-0-d91545d794f7@linutronix.de/
[1] https://lore.kernel.org/lkml/20251203-uapi-fcntl-v1-1-490c67bf3425@linutronix.de/
Thomas
^ permalink raw reply [flat|nested] 21+ messages in thread
* Re: [PATCH v2] fuse: uapi: use UAPI types
2026-01-05 8:50 ` Bernd Schubert
2026-01-05 9:57 ` Thomas Weißschuh
@ 2026-01-05 12:09 ` Arnd Bergmann
2026-01-08 22:12 ` Bernd Schubert
2026-01-08 22:14 ` Bernd Schubert
1 sibling, 2 replies; 21+ messages in thread
From: Arnd Bergmann @ 2026-01-05 12:09 UTC (permalink / raw)
To: Bernd Schubert, Thomas Weißschuh
Cc: Miklos Szeredi, linux-fsdevel, linux-kernel
On Mon, Jan 5, 2026, at 09:50, Bernd Schubert wrote:
> On 1/5/26 09:40, Thomas Weißschuh wrote:
>> On Sat, Jan 03, 2026 at 01:44:49PM +0100, Bernd Schubert wrote:
>>
>>>> libfuse3.so.3.19.0.p/fuse_uring.c.o -c
>>>> ../../../home/runner/work/libfuse/libfuse/lib/fuse_uring.c
>>>> ../../../home/runner/work/libfuse/libfuse/lib/fuse_uring.c:197:5: error:
>>>> format specifies type 'unsigned long' but the argument has type '__u64'
>>>> (aka 'unsigned long long') [-Werror,-Wformat]
>>>> 196 | fuse_log(FUSE_LOG_DEBUG, " unique: %" PRIu64
>>>> ", result=%d\n",
>>>> | ~~~~~~~~~
>>>> 197 | out->unique, ent_in_out->payload_sz);
>>>> | ^~~~~~~~~~~
>>>> 1 error generated.
>>>>
>>>>
>>>> I can certainly work it around in libfuse by adding a cast, IMHO,
>>>> PRIu64 is the right format.
>>
>> PRIu64 is indeed the right format for uint64_t. Unfortunately not necessarily
>> for __u64. As the vast majority of the UAPI headers to use the UAPI types,
>> adding a cast in this case is already necessary for most UAPI users.
Which target did the warning show up on? I would expect the patch
to not have changed anything for BSD, since not defining __linux__
makes it use the stdint types after all.
On alpha/mips/powerpc, the default is to use 'unsigned long' unless
the __SANE_USERSPACE_TYPES__ macro is defined before linux/types.h
gets included, and we may be able to do the same on other
architectures as well for consistency. All the other 64-bit
architectures (x86-64, arm64, riscv64, s390x, parisc64, sparc64)
only provide the ll64 types from uapi but seem to use the l64
version both in gcc's predefined types and in glibc.
>>> I think what would work is the attached version. Short interesting part
>>>
>>> #if defined(__KERNEL__)
>>> #include <linux/types.h>
>>> typedef __u8 fuse_u8;
>>> typedef __u16 fuse_u16;
>>> typedef __u32 fuse_u32;
>>> typedef __u64 fuse_u64;
>>> typedef __s8 fuse_s8;
>>> typedef __s16 fuse_s16;
>>> typedef __s32 fuse_s32;
>>> typedef __s64 fuse_s64;
>>> #else
>>> #include <stdint.h>
>>> typedef uint8_t fuse_u8;
>>> typedef uint16_t fuse_u16;
>>> typedef uint32_t fuse_u32;
>>> typedef uint64_t fuse_u64;
>>> typedef int8_t fuse_s8;
>>> typedef int16_t fuse_s16;
>>> typedef int32_t fuse_s32;
>>> typedef int64_t fuse_s64;
>>> #endif
>>
>> Unfortunately this is equivalent to the status quo.
>> It contains a dependency on the libc header stdint.h when used from userspace.
>>
>> IMO the best way forward is to use the v2 patch and add a cast in fuse_uring.c.
>
> libfuse is easy, but libfuse is just one library that might use/copy the
> header. If libfuse breaks the others might as well.
I don't think we'll find a solution that won't break somewhere,
and using the kernel-internal types at least makes it consistent
with the rest of the kernel headers.
If we can rely on compiling with a modern compiler (any version of
clang, or gcc-4.5+), it predefines a __UINT64_TYPE__ macro that
could be used for custom typedef:
#ifdef __UINT64_TYPE__
typedef __UINT64_TYPE__ fuse_u64;
typedef __INT64_TYPE__ fuse_s64;
typedef __UINT32_TYPE__ fuse_u32;
typedef __INT32_TYPE__ fuse_s32;
...
#else
#include <stdint.h>
typedef uint64_t fuse_u64;
typedef int64_t fuse_s64;
typedef uint32_t fuse_u32;
typedef int32_t fuse_s32;
...
#endif
The #else side could perhaps be left out here.
> Maybe you could explain your issue more detailed? I.e. how are you using
> this include exactly?
I'm interested specifically in two aspects:
- being able to build-test all kernel headers for continuous
integration testing, without having to have access to libc
headers for each target architecture when cross compiling.
- layering kernel headers such that kernel headers never depend
on libc headers and (in a later stage) any kernel header
can be included without clashing with libc definitions.
Arnd
^ permalink raw reply [flat|nested] 21+ messages in thread
* Re: [PATCH v2] fuse: uapi: use UAPI types
2025-12-30 12:10 [PATCH v2] fuse: uapi: use UAPI types Thomas Weißschuh
2025-12-30 21:09 ` Arnd Bergmann
2026-01-02 22:27 ` Bernd Schubert
@ 2026-01-05 12:45 ` Miklos Szeredi
2 siblings, 0 replies; 21+ messages in thread
From: Miklos Szeredi @ 2026-01-05 12:45 UTC (permalink / raw)
To: Thomas Weißschuh; +Cc: linux-fsdevel, linux-kernel, Arnd Bergmann
On Tue, 30 Dec 2025 at 13:11, Thomas Weißschuh
<thomas.weissschuh@linutronix.de> wrote:
>
> Using libc types and headers from the UAPI headers is problematic as it
> introduces a dependency on a full C toolchain.
Can you please elaborate?
Is there a real use case that is being fixed by this?
Or is this some theoretical thing?
Thanks,
Miklos
^ permalink raw reply [flat|nested] 21+ messages in thread
* Re: [PATCH v2] fuse: uapi: use UAPI types
2026-01-05 12:09 ` Arnd Bergmann
@ 2026-01-08 22:12 ` Bernd Schubert
2026-01-09 8:11 ` Thomas Weißschuh
2026-01-08 22:14 ` Bernd Schubert
1 sibling, 1 reply; 21+ messages in thread
From: Bernd Schubert @ 2026-01-08 22:12 UTC (permalink / raw)
To: Arnd Bergmann, Thomas Weißschuh
Cc: Miklos Szeredi, linux-fsdevel, linux-kernel
On 1/5/26 13:09, Arnd Bergmann wrote:
> On Mon, Jan 5, 2026, at 09:50, Bernd Schubert wrote:
>> On 1/5/26 09:40, Thomas Weißschuh wrote:
>>> On Sat, Jan 03, 2026 at 01:44:49PM +0100, Bernd Schubert wrote:
>>>
>>>>> libfuse3.so.3.19.0.p/fuse_uring.c.o -c
>>>>> ../../../home/runner/work/libfuse/libfuse/lib/fuse_uring.c
>>>>> ../../../home/runner/work/libfuse/libfuse/lib/fuse_uring.c:197:5: error:
>>>>> format specifies type 'unsigned long' but the argument has type '__u64'
>>>>> (aka 'unsigned long long') [-Werror,-Wformat]
>>>>> 196 | fuse_log(FUSE_LOG_DEBUG, " unique: %" PRIu64
>>>>> ", result=%d\n",
>>>>> | ~~~~~~~~~
>>>>> 197 | out->unique, ent_in_out->payload_sz);
>>>>> | ^~~~~~~~~~~
>>>>> 1 error generated.
>>>>>
>>>>>
>>>>> I can certainly work it around in libfuse by adding a cast, IMHO,
>>>>> PRIu64 is the right format.
>>>
>>> PRIu64 is indeed the right format for uint64_t. Unfortunately not necessarily
>>> for __u64. As the vast majority of the UAPI headers to use the UAPI types,
>>> adding a cast in this case is already necessary for most UAPI users.
>
> Which target did the warning show up on? I would expect the patch
> to not have changed anything for BSD, since not defining __linux__
> makes it use the stdint types after all.
>
> On alpha/mips/powerpc, the default is to use 'unsigned long' unless
> the __SANE_USERSPACE_TYPES__ macro is defined before linux/types.h
> gets included, and we may be able to do the same on other
> architectures as well for consistency. All the other 64-bit
> architectures (x86-64, arm64, riscv64, s390x, parisc64, sparc64)
> only provide the ll64 types from uapi but seem to use the l64
> version both in gcc's predefined types and in glibc.
>
>>>> I think what would work is the attached version. Short interesting part
>>>>
>>>> #if defined(__KERNEL__)
>>>> #include <linux/types.h>
>>>> typedef __u8 fuse_u8;
>>>> typedef __u16 fuse_u16;
>>>> typedef __u32 fuse_u32;
>>>> typedef __u64 fuse_u64;
>>>> typedef __s8 fuse_s8;
>>>> typedef __s16 fuse_s16;
>>>> typedef __s32 fuse_s32;
>>>> typedef __s64 fuse_s64;
>>>> #else
>>>> #include <stdint.h>
>>>> typedef uint8_t fuse_u8;
>>>> typedef uint16_t fuse_u16;
>>>> typedef uint32_t fuse_u32;
>>>> typedef uint64_t fuse_u64;
>>>> typedef int8_t fuse_s8;
>>>> typedef int16_t fuse_s16;
>>>> typedef int32_t fuse_s32;
>>>> typedef int64_t fuse_s64;
>>>> #endif
>>>
>>> Unfortunately this is equivalent to the status quo.
>>> It contains a dependency on the libc header stdint.h when used from userspace.
>>>
>>> IMO the best way forward is to use the v2 patch and add a cast in fuse_uring.c.
>>
>> libfuse is easy, but libfuse is just one library that might use/copy the
>> header. If libfuse breaks the others might as well.
>
> I don't think we'll find a solution that won't break somewhere,
> and using the kernel-internal types at least makes it consistent
> with the rest of the kernel headers.
>
> If we can rely on compiling with a modern compiler (any version of
> clang, or gcc-4.5+), it predefines a __UINT64_TYPE__ macro that
> could be used for custom typedef:
>
> #ifdef __UINT64_TYPE__
> typedef __UINT64_TYPE__ fuse_u64;
> typedef __INT64_TYPE__ fuse_s64;
> typedef __UINT32_TYPE__ fuse_u32;
> typedef __INT32_TYPE__ fuse_s32;
> ...
> #else
> #include <stdint.h>
> typedef uint64_t fuse_u64;
> typedef int64_t fuse_s64;
> typedef uint32_t fuse_u32;
> typedef int32_t fuse_s32;
> ...
> #endif
I personally like this version.
>
> The #else side could perhaps be left out here.
Maybe we should keep it for safety? Less for kernel, but more for
userspace- we don't know in which environments/libs the header is used.
>
>> Maybe you could explain your issue more detailed? I.e. how are you using
>> this include exactly?
>
> I'm interested specifically in two aspects:
>
> - being able to build-test all kernel headers for continuous
> integration testing, without having to have access to libc
> headers for each target architecture when cross compiling.
>
> - layering kernel headers such that kernel headers never depend
> on libc headers and (in a later stage) any kernel header
> can be included without clashing with libc definitions.
Thank you, I think it would good to add these details to the commit message.
Thanks,
Bernd
^ permalink raw reply [flat|nested] 21+ messages in thread
* Re: [PATCH v2] fuse: uapi: use UAPI types
2026-01-05 12:09 ` Arnd Bergmann
2026-01-08 22:12 ` Bernd Schubert
@ 2026-01-08 22:14 ` Bernd Schubert
1 sibling, 0 replies; 21+ messages in thread
From: Bernd Schubert @ 2026-01-08 22:14 UTC (permalink / raw)
To: Arnd Bergmann, Thomas Weißschuh
Cc: Miklos Szeredi, linux-fsdevel, linux-kernel
On 1/5/26 13:09, Arnd Bergmann wrote:
> On Mon, Jan 5, 2026, at 09:50, Bernd Schubert wrote:
>> On 1/5/26 09:40, Thomas Weißschuh wrote:
>>> On Sat, Jan 03, 2026 at 01:44:49PM +0100, Bernd Schubert wrote:
>>>
>>>>> libfuse3.so.3.19.0.p/fuse_uring.c.o -c
>>>>> ../../../home/runner/work/libfuse/libfuse/lib/fuse_uring.c
>>>>> ../../../home/runner/work/libfuse/libfuse/lib/fuse_uring.c:197:5: error:
>>>>> format specifies type 'unsigned long' but the argument has type '__u64'
>>>>> (aka 'unsigned long long') [-Werror,-Wformat]
>>>>> 196 | fuse_log(FUSE_LOG_DEBUG, " unique: %" PRIu64
>>>>> ", result=%d\n",
>>>>> | ~~~~~~~~~
>>>>> 197 | out->unique, ent_in_out->payload_sz);
>>>>> | ^~~~~~~~~~~
>>>>> 1 error generated.
>>>>>
>>>>>
>>>>> I can certainly work it around in libfuse by adding a cast, IMHO,
>>>>> PRIu64 is the right format.
>>>
>>> PRIu64 is indeed the right format for uint64_t. Unfortunately not necessarily
>>> for __u64. As the vast majority of the UAPI headers to use the UAPI types,
>>> adding a cast in this case is already necessary for most UAPI users.
>
> Which target did the warning show up on? I would expect the patch
> to not have changed anything for BSD, since not defining __linux__
> makes it use the stdint types after all.
Sorry for late reply, default Ubuntu x86_64 target.
^ permalink raw reply [flat|nested] 21+ messages in thread
* Re: [PATCH v2] fuse: uapi: use UAPI types
2026-01-08 22:12 ` Bernd Schubert
@ 2026-01-09 8:11 ` Thomas Weißschuh
2026-01-09 10:38 ` David Laight
0 siblings, 1 reply; 21+ messages in thread
From: Thomas Weißschuh @ 2026-01-09 8:11 UTC (permalink / raw)
To: Bernd Schubert; +Cc: Arnd Bergmann, Miklos Szeredi, linux-fsdevel, linux-kernel
On Thu, Jan 08, 2026 at 11:12:29PM +0100, Bernd Schubert wrote:
>
>
> On 1/5/26 13:09, Arnd Bergmann wrote:
> > On Mon, Jan 5, 2026, at 09:50, Bernd Schubert wrote:
> >> On 1/5/26 09:40, Thomas Weißschuh wrote:
> >>> On Sat, Jan 03, 2026 at 01:44:49PM +0100, Bernd Schubert wrote:
> >>>
> >>>>> libfuse3.so.3.19.0.p/fuse_uring.c.o -c
> >>>>> ../../../home/runner/work/libfuse/libfuse/lib/fuse_uring.c
> >>>>> ../../../home/runner/work/libfuse/libfuse/lib/fuse_uring.c:197:5: error:
> >>>>> format specifies type 'unsigned long' but the argument has type '__u64'
> >>>>> (aka 'unsigned long long') [-Werror,-Wformat]
> >>>>> 196 | fuse_log(FUSE_LOG_DEBUG, " unique: %" PRIu64
> >>>>> ", result=%d\n",
> >>>>> | ~~~~~~~~~
> >>>>> 197 | out->unique, ent_in_out->payload_sz);
> >>>>> | ^~~~~~~~~~~
> >>>>> 1 error generated.
> >>>>>
> >>>>>
> >>>>> I can certainly work it around in libfuse by adding a cast, IMHO,
> >>>>> PRIu64 is the right format.
> >>>
> >>> PRIu64 is indeed the right format for uint64_t. Unfortunately not necessarily
> >>> for __u64. As the vast majority of the UAPI headers to use the UAPI types,
> >>> adding a cast in this case is already necessary for most UAPI users.
> >
> > Which target did the warning show up on? I would expect the patch
> > to not have changed anything for BSD, since not defining __linux__
> > makes it use the stdint types after all.
> >
> > On alpha/mips/powerpc, the default is to use 'unsigned long' unless
> > the __SANE_USERSPACE_TYPES__ macro is defined before linux/types.h
> > gets included, and we may be able to do the same on other
> > architectures as well for consistency. All the other 64-bit
> > architectures (x86-64, arm64, riscv64, s390x, parisc64, sparc64)
> > only provide the ll64 types from uapi but seem to use the l64
> > version both in gcc's predefined types and in glibc.
> >
> >>>> I think what would work is the attached version. Short interesting part
> >>>>
> >>>> #if defined(__KERNEL__)
> >>>> #include <linux/types.h>
> >>>> typedef __u8 fuse_u8;
> >>>> typedef __u16 fuse_u16;
> >>>> typedef __u32 fuse_u32;
> >>>> typedef __u64 fuse_u64;
> >>>> typedef __s8 fuse_s8;
> >>>> typedef __s16 fuse_s16;
> >>>> typedef __s32 fuse_s32;
> >>>> typedef __s64 fuse_s64;
> >>>> #else
> >>>> #include <stdint.h>
> >>>> typedef uint8_t fuse_u8;
> >>>> typedef uint16_t fuse_u16;
> >>>> typedef uint32_t fuse_u32;
> >>>> typedef uint64_t fuse_u64;
> >>>> typedef int8_t fuse_s8;
> >>>> typedef int16_t fuse_s16;
> >>>> typedef int32_t fuse_s32;
> >>>> typedef int64_t fuse_s64;
> >>>> #endif
> >>>
> >>> Unfortunately this is equivalent to the status quo.
> >>> It contains a dependency on the libc header stdint.h when used from userspace.
> >>>
> >>> IMO the best way forward is to use the v2 patch and add a cast in fuse_uring.c.
> >>
> >> libfuse is easy, but libfuse is just one library that might use/copy the
> >> header. If libfuse breaks the others might as well.
> >
> > I don't think we'll find a solution that won't break somewhere,
> > and using the kernel-internal types at least makes it consistent
> > with the rest of the kernel headers.
> >
> > If we can rely on compiling with a modern compiler (any version of
> > clang, or gcc-4.5+), it predefines a __UINT64_TYPE__ macro that
> > could be used for custom typedef:
> >
> > #ifdef __UINT64_TYPE__
> > typedef __UINT64_TYPE__ fuse_u64;
> > typedef __INT64_TYPE__ fuse_s64;
> > typedef __UINT32_TYPE__ fuse_u32;
> > typedef __INT32_TYPE__ fuse_s32;
> > ...
> > #else
> > #include <stdint.h>
> > typedef uint64_t fuse_u64;
> > typedef int64_t fuse_s64;
> > typedef uint32_t fuse_u32;
> > typedef int32_t fuse_s32;
> > ...
> > #endif
>
> I personally like this version.
Ack, I'll use this. Although I am not sure why uint64_t and __UINT64_TYPE__
should be guaranteed to be identical.
> > The #else side could perhaps be left out here.
>
> Maybe we should keep it for safety? Less for kernel, but more for
> userspace- we don't know in which environments/libs the header is used.
Ack.
> >> Maybe you could explain your issue more detailed? I.e. how are you using
> >> this include exactly?
> >
> > I'm interested specifically in two aspects:
> >
> > - being able to build-test all kernel headers for continuous
> > integration testing, without having to have access to libc
> > headers for each target architecture when cross compiling.
> >
> > - layering kernel headers such that kernel headers never depend
> > on libc headers and (in a later stage) any kernel header
> > can be included without clashing with libc definitions.
>
> Thank you, I think it would good to add these details to the commit message.
Ack.
Thomas
^ permalink raw reply [flat|nested] 21+ messages in thread
* Re: [PATCH v2] fuse: uapi: use UAPI types
2026-01-09 8:11 ` Thomas Weißschuh
@ 2026-01-09 10:38 ` David Laight
2026-01-09 10:45 ` Bernd Schubert
0 siblings, 1 reply; 21+ messages in thread
From: David Laight @ 2026-01-09 10:38 UTC (permalink / raw)
To: Thomas Weißschuh
Cc: Bernd Schubert, Arnd Bergmann, Miklos Szeredi, linux-fsdevel,
linux-kernel
On Fri, 9 Jan 2026 09:11:28 +0100
Thomas Weißschuh <thomas.weissschuh@linutronix.de> wrote:
> On Thu, Jan 08, 2026 at 11:12:29PM +0100, Bernd Schubert wrote:
> >
> >
> > On 1/5/26 13:09, Arnd Bergmann wrote:
> > > On Mon, Jan 5, 2026, at 09:50, Bernd Schubert wrote:
...
> > > I don't think we'll find a solution that won't break somewhere,
> > > and using the kernel-internal types at least makes it consistent
> > > with the rest of the kernel headers.
> > >
> > > If we can rely on compiling with a modern compiler (any version of
> > > clang, or gcc-4.5+), it predefines a __UINT64_TYPE__ macro that
> > > could be used for custom typedef:
> > >
> > > #ifdef __UINT64_TYPE__
> > > typedef __UINT64_TYPE__ fuse_u64;
> > > typedef __INT64_TYPE__ fuse_s64;
> > > typedef __UINT32_TYPE__ fuse_u32;
> > > typedef __INT32_TYPE__ fuse_s32;
> > > ...
> > > #else
> > > #include <stdint.h>
> > > typedef uint64_t fuse_u64;
> > > typedef int64_t fuse_s64;
> > > typedef uint32_t fuse_u32;
> > > typedef int32_t fuse_s32;
> > > ...
> > > #endif
> >
> > I personally like this version.
>
> Ack, I'll use this. Although I am not sure why uint64_t and __UINT64_TYPE__
> should be guaranteed to be identical.
Indeed, on 64bit the 64bit types could be 'long' or 'long long'.
You've still got the problem of the correct printf format specifier.
On 32bit the 32bit types could be 'int' or 'long'.
stdint.h 'solves' the printf issue with the (horrid) PRIu64 defines.
But I don't know how you find out what gcc's format checking uses.
So you might have to cast all the values to underlying C types in
order pass the printf format checks.
At which point you might as well have:
typedef unsigned int fuse_u32;
typedef unsigned long long fuse_u64;
_Static_assert(sizeof (fuse_u32) == 4 && sizeof (fuse_u64) == 8);
And then use %x and %llx in the format strings.
David
^ permalink raw reply [flat|nested] 21+ messages in thread
* Re: [PATCH v2] fuse: uapi: use UAPI types
2026-01-09 10:38 ` David Laight
@ 2026-01-09 10:45 ` Bernd Schubert
2026-01-09 10:55 ` Thomas Weißschuh
0 siblings, 1 reply; 21+ messages in thread
From: Bernd Schubert @ 2026-01-09 10:45 UTC (permalink / raw)
To: David Laight, Thomas Weißschuh
Cc: Arnd Bergmann, Miklos Szeredi, linux-fsdevel, linux-kernel
On 1/9/26 11:38, David Laight wrote:
> On Fri, 9 Jan 2026 09:11:28 +0100
> Thomas Weißschuh <thomas.weissschuh@linutronix.de> wrote:
>
>> On Thu, Jan 08, 2026 at 11:12:29PM +0100, Bernd Schubert wrote:
>>>
>>>
>>> On 1/5/26 13:09, Arnd Bergmann wrote:
>>>> On Mon, Jan 5, 2026, at 09:50, Bernd Schubert wrote:
> ...
>>>> I don't think we'll find a solution that won't break somewhere,
>>>> and using the kernel-internal types at least makes it consistent
>>>> with the rest of the kernel headers.
>>>>
>>>> If we can rely on compiling with a modern compiler (any version of
>>>> clang, or gcc-4.5+), it predefines a __UINT64_TYPE__ macro that
>>>> could be used for custom typedef:
>>>>
>>>> #ifdef __UINT64_TYPE__
>>>> typedef __UINT64_TYPE__ fuse_u64;
>>>> typedef __INT64_TYPE__ fuse_s64;
>>>> typedef __UINT32_TYPE__ fuse_u32;
>>>> typedef __INT32_TYPE__ fuse_s32;
>>>> ...
>>>> #else
>>>> #include <stdint.h>
>>>> typedef uint64_t fuse_u64;
>>>> typedef int64_t fuse_s64;
>>>> typedef uint32_t fuse_u32;
>>>> typedef int32_t fuse_s32;
>>>> ...
>>>> #endif
>>>
>>> I personally like this version.
>>
>> Ack, I'll use this. Although I am not sure why uint64_t and __UINT64_TYPE__
>> should be guaranteed to be identical.
>
> Indeed, on 64bit the 64bit types could be 'long' or 'long long'.
> You've still got the problem of the correct printf format specifier.
> On 32bit the 32bit types could be 'int' or 'long'.
>
> stdint.h 'solves' the printf issue with the (horrid) PRIu64 defines.
> But I don't know how you find out what gcc's format checking uses.
> So you might have to cast all the values to underlying C types in
> order pass the printf format checks.
> At which point you might as well have:
> typedef unsigned int fuse_u32;
> typedef unsigned long long fuse_u64;
> _Static_assert(sizeof (fuse_u32) == 4 && sizeof (fuse_u64) == 8);
> And then use %x and %llx in the format strings.
The test PR from Thomas succeeds in compilation and build testing. Which
includes 32-bit cross compilation
https://github.com/libfuse/libfuse/pull/1417
Checkpatch complains a bit, but I would ignore that - I had mostly only
added checkpatch to ensure people are submitting with the right
formatting (lots of commits with spaces, but the project follows kernel
style).
Thanks,
Bernd1
^ permalink raw reply [flat|nested] 21+ messages in thread
* Re: [PATCH v2] fuse: uapi: use UAPI types
2026-01-09 10:45 ` Bernd Schubert
@ 2026-01-09 10:55 ` Thomas Weißschuh
2026-01-09 11:36 ` Bernd Schubert
2026-01-09 13:11 ` David Laight
0 siblings, 2 replies; 21+ messages in thread
From: Thomas Weißschuh @ 2026-01-09 10:55 UTC (permalink / raw)
To: Bernd Schubert
Cc: David Laight, Arnd Bergmann, Miklos Szeredi, linux-fsdevel,
linux-kernel
On Fri, Jan 09, 2026 at 11:45:33AM +0100, Bernd Schubert wrote:
>
>
> On 1/9/26 11:38, David Laight wrote:
> > On Fri, 9 Jan 2026 09:11:28 +0100
> > Thomas Weißschuh <thomas.weissschuh@linutronix.de> wrote:
> >
> >> On Thu, Jan 08, 2026 at 11:12:29PM +0100, Bernd Schubert wrote:
> >>>
> >>>
> >>> On 1/5/26 13:09, Arnd Bergmann wrote:
> >>>> On Mon, Jan 5, 2026, at 09:50, Bernd Schubert wrote:
> > ...
> >>>> I don't think we'll find a solution that won't break somewhere,
> >>>> and using the kernel-internal types at least makes it consistent
> >>>> with the rest of the kernel headers.
> >>>>
> >>>> If we can rely on compiling with a modern compiler (any version of
> >>>> clang, or gcc-4.5+), it predefines a __UINT64_TYPE__ macro that
> >>>> could be used for custom typedef:
> >>>>
> >>>> #ifdef __UINT64_TYPE__
> >>>> typedef __UINT64_TYPE__ fuse_u64;
> >>>> typedef __INT64_TYPE__ fuse_s64;
> >>>> typedef __UINT32_TYPE__ fuse_u32;
> >>>> typedef __INT32_TYPE__ fuse_s32;
> >>>> ...
> >>>> #else
> >>>> #include <stdint.h>
> >>>> typedef uint64_t fuse_u64;
> >>>> typedef int64_t fuse_s64;
> >>>> typedef uint32_t fuse_u32;
> >>>> typedef int32_t fuse_s32;
> >>>> ...
> >>>> #endif
> >>>
> >>> I personally like this version.
> >>
> >> Ack, I'll use this. Although I am not sure why uint64_t and __UINT64_TYPE__
> >> should be guaranteed to be identical.
> >
> > Indeed, on 64bit the 64bit types could be 'long' or 'long long'.
> > You've still got the problem of the correct printf format specifier.
> > On 32bit the 32bit types could be 'int' or 'long'.
> >
> > stdint.h 'solves' the printf issue with the (horrid) PRIu64 defines.
> > But I don't know how you find out what gcc's format checking uses.
> > So you might have to cast all the values to underlying C types in
> > order pass the printf format checks.
> > At which point you might as well have:
> > typedef unsigned int fuse_u32;
> > typedef unsigned long long fuse_u64;
> > _Static_assert(sizeof (fuse_u32) == 4 && sizeof (fuse_u64) == 8);
> > And then use %x and %llx in the format strings.
These changes to format strings are what we are trying to avoid.
> The test PR from Thomas succeeds in compilation and build testing. Which
> includes 32-bit cross compilation
>
> https://github.com/libfuse/libfuse/pull/1417
Unforunately there might still be issues on configurations not tested by the CI
where the types between the compiler and libc won't match.
But if it works sufficiently for you, I'm fine with it.
Also with the proposal from Arnd there were format strings warnings when
building the kernel, so now I have this:
#if defined(__KERNEL__)
#include <linux/types.h>
typedef __u64 fuse_u64;
...
#elif defined(__UINT64_TYPE__)
typedef __UINT64_TYPE__ fuse_u64;
...
#else
#include <stdint.h>
typedef uint64_t fuse_u64;
...
#endif
Thomas
^ permalink raw reply [flat|nested] 21+ messages in thread
* Re: [PATCH v2] fuse: uapi: use UAPI types
2026-01-09 10:55 ` Thomas Weißschuh
@ 2026-01-09 11:36 ` Bernd Schubert
2026-01-09 13:11 ` David Laight
1 sibling, 0 replies; 21+ messages in thread
From: Bernd Schubert @ 2026-01-09 11:36 UTC (permalink / raw)
To: Thomas Weißschuh
Cc: David Laight, Arnd Bergmann, Miklos Szeredi, linux-fsdevel,
linux-kernel
On 1/9/26 11:55, Thomas Weißschuh wrote:
> On Fri, Jan 09, 2026 at 11:45:33AM +0100, Bernd Schubert wrote:
>>
>>
>> On 1/9/26 11:38, David Laight wrote:
>>> On Fri, 9 Jan 2026 09:11:28 +0100
>>> Thomas Weißschuh <thomas.weissschuh@linutronix.de> wrote:
>>>
>>>> On Thu, Jan 08, 2026 at 11:12:29PM +0100, Bernd Schubert wrote:
>>>>>
>>>>>
>>>>> On 1/5/26 13:09, Arnd Bergmann wrote:
>>>>>> On Mon, Jan 5, 2026, at 09:50, Bernd Schubert wrote:
>>> ...
>>>>>> I don't think we'll find a solution that won't break somewhere,
>>>>>> and using the kernel-internal types at least makes it consistent
>>>>>> with the rest of the kernel headers.
>>>>>>
>>>>>> If we can rely on compiling with a modern compiler (any version of
>>>>>> clang, or gcc-4.5+), it predefines a __UINT64_TYPE__ macro that
>>>>>> could be used for custom typedef:
>>>>>>
>>>>>> #ifdef __UINT64_TYPE__
>>>>>> typedef __UINT64_TYPE__ fuse_u64;
>>>>>> typedef __INT64_TYPE__ fuse_s64;
>>>>>> typedef __UINT32_TYPE__ fuse_u32;
>>>>>> typedef __INT32_TYPE__ fuse_s32;
>>>>>> ...
>>>>>> #else
>>>>>> #include <stdint.h>
>>>>>> typedef uint64_t fuse_u64;
>>>>>> typedef int64_t fuse_s64;
>>>>>> typedef uint32_t fuse_u32;
>>>>>> typedef int32_t fuse_s32;
>>>>>> ...
>>>>>> #endif
>>>>>
>>>>> I personally like this version.
>>>>
>>>> Ack, I'll use this. Although I am not sure why uint64_t and __UINT64_TYPE__
>>>> should be guaranteed to be identical.
>>>
>>> Indeed, on 64bit the 64bit types could be 'long' or 'long long'.
>>> You've still got the problem of the correct printf format specifier.
>>> On 32bit the 32bit types could be 'int' or 'long'.
>>>
>>> stdint.h 'solves' the printf issue with the (horrid) PRIu64 defines.
>>> But I don't know how you find out what gcc's format checking uses.
>>> So you might have to cast all the values to underlying C types in
>>> order pass the printf format checks.
>>> At which point you might as well have:
>>> typedef unsigned int fuse_u32;
>>> typedef unsigned long long fuse_u64;
>>> _Static_assert(sizeof (fuse_u32) == 4 && sizeof (fuse_u64) == 8);
>>> And then use %x and %llx in the format strings.
>
> These changes to format strings are what we are trying to avoid.
>
>> The test PR from Thomas succeeds in compilation and build testing. Which
>> includes 32-bit cross compilation
>>
>> https://github.com/libfuse/libfuse/pull/1417
>
> Unforunately there might still be issues on configurations not tested by the CI
> where the types between the compiler and libc won't match.
> But if it works sufficiently for you, I'm fine with it.
I don't have a problem to adopt libfuse - that is the simple part. The
harder part are other fuse implementations that use the same header. And
they will complain to Miklos if compilation fails.
Which is why it is important that we catch beforehand as many issues as
we can and then the commit message should explain very detailed the use
case. I.e. if something breaks for others, we can still point to you use
case that would be broken without these changes.
>
> Also with the proposal from Arnd there were format strings warnings when
> building the kernel, so now I have this:
>
> #if defined(__KERNEL__)
> #include <linux/types.h>
> typedef __u64 fuse_u64;
> ...
>
> #elif defined(__UINT64_TYPE__)
> typedef __UINT64_TYPE__ fuse_u64;
> ...
>
> #else
> #include <stdint.h>
> typedef uint64_t fuse_u64;
> ...
> #endif
I guess you can see why Miklos is resisting these changes without a good
use case :)
Thanks,
Bernd
^ permalink raw reply [flat|nested] 21+ messages in thread
* Re: [PATCH v2] fuse: uapi: use UAPI types
2026-01-09 10:55 ` Thomas Weißschuh
2026-01-09 11:36 ` Bernd Schubert
@ 2026-01-09 13:11 ` David Laight
2026-01-09 13:46 ` Bernd Schubert
1 sibling, 1 reply; 21+ messages in thread
From: David Laight @ 2026-01-09 13:11 UTC (permalink / raw)
To: Thomas Weißschuh
Cc: Bernd Schubert, Arnd Bergmann, Miklos Szeredi, linux-fsdevel,
linux-kernel
On Fri, 9 Jan 2026 11:55:30 +0100
Thomas Weißschuh <thomas.weissschuh@linutronix.de> wrote:
> On Fri, Jan 09, 2026 at 11:45:33AM +0100, Bernd Schubert wrote:
> >
> >
> > On 1/9/26 11:38, David Laight wrote:
> > > On Fri, 9 Jan 2026 09:11:28 +0100
> > > Thomas Weißschuh <thomas.weissschuh@linutronix.de> wrote:
> > >
> > >> On Thu, Jan 08, 2026 at 11:12:29PM +0100, Bernd Schubert wrote:
> > >>>
> > >>>
> > >>> On 1/5/26 13:09, Arnd Bergmann wrote:
> > >>>> On Mon, Jan 5, 2026, at 09:50, Bernd Schubert wrote:
> > > ...
> > >>>> I don't think we'll find a solution that won't break somewhere,
> > >>>> and using the kernel-internal types at least makes it consistent
> > >>>> with the rest of the kernel headers.
> > >>>>
> > >>>> If we can rely on compiling with a modern compiler (any version of
> > >>>> clang, or gcc-4.5+), it predefines a __UINT64_TYPE__ macro that
> > >>>> could be used for custom typedef:
> > >>>>
> > >>>> #ifdef __UINT64_TYPE__
> > >>>> typedef __UINT64_TYPE__ fuse_u64;
> > >>>> typedef __INT64_TYPE__ fuse_s64;
> > >>>> typedef __UINT32_TYPE__ fuse_u32;
> > >>>> typedef __INT32_TYPE__ fuse_s32;
> > >>>> ...
> > >>>> #else
> > >>>> #include <stdint.h>
> > >>>> typedef uint64_t fuse_u64;
> > >>>> typedef int64_t fuse_s64;
> > >>>> typedef uint32_t fuse_u32;
> > >>>> typedef int32_t fuse_s32;
> > >>>> ...
> > >>>> #endif
> > >>>
> > >>> I personally like this version.
> > >>
> > >> Ack, I'll use this. Although I am not sure why uint64_t and __UINT64_TYPE__
> > >> should be guaranteed to be identical.
> > >
> > > Indeed, on 64bit the 64bit types could be 'long' or 'long long'.
> > > You've still got the problem of the correct printf format specifier.
> > > On 32bit the 32bit types could be 'int' or 'long'.
> > >
> > > stdint.h 'solves' the printf issue with the (horrid) PRIu64 defines.
> > > But I don't know how you find out what gcc's format checking uses.
> > > So you might have to cast all the values to underlying C types in
> > > order pass the printf format checks.
> > > At which point you might as well have:
> > > typedef unsigned int fuse_u32;
> > > typedef unsigned long long fuse_u64;
> > > _Static_assert(sizeof (fuse_u32) == 4 && sizeof (fuse_u64) == 8);
> > > And then use %x and %llx in the format strings.
>
> These changes to format strings are what we are trying to avoid.
Where do PRIu64 (and friends) come from if you don't include stdint.h ?
I think Linux kernel always uses 'int' and 'long long', but other
compilation environments might use 'long' for one of them [1].
So while you can define ABI correct PRIu64 and PRIu32 you can't define
ones that pass compiler format checking without knowing the underlying
C types.
[1] I can't remember where, but it might have been NetBSD where different
architectures managed to have different definitions!
David
>
> > The test PR from Thomas succeeds in compilation and build testing. Which
> > includes 32-bit cross compilation
> >
> > https://github.com/libfuse/libfuse/pull/1417
>
> Unforunately there might still be issues on configurations not tested by the CI
> where the types between the compiler and libc won't match.
> But if it works sufficiently for you, I'm fine with it.
>
> Also with the proposal from Arnd there were format strings warnings when
> building the kernel, so now I have this:
>
> #if defined(__KERNEL__)
> #include <linux/types.h>
> typedef __u64 fuse_u64;
> ...
>
> #elif defined(__UINT64_TYPE__)
> typedef __UINT64_TYPE__ fuse_u64;
> ...
>
> #else
> #include <stdint.h>
> typedef uint64_t fuse_u64;
> ...
> #endif
>
>
> Thomas
^ permalink raw reply [flat|nested] 21+ messages in thread
* Re: [PATCH v2] fuse: uapi: use UAPI types
2026-01-09 13:11 ` David Laight
@ 2026-01-09 13:46 ` Bernd Schubert
2026-01-09 19:13 ` David Laight
0 siblings, 1 reply; 21+ messages in thread
From: Bernd Schubert @ 2026-01-09 13:46 UTC (permalink / raw)
To: David Laight, Thomas Weißschuh
Cc: Arnd Bergmann, Miklos Szeredi, linux-fsdevel, linux-kernel
On 1/9/26 14:11, David Laight wrote:
> On Fri, 9 Jan 2026 11:55:30 +0100
> Thomas Weißschuh <thomas.weissschuh@linutronix.de> wrote:
>
>> On Fri, Jan 09, 2026 at 11:45:33AM +0100, Bernd Schubert wrote:
>>>
>>>
>>> On 1/9/26 11:38, David Laight wrote:
>>>> On Fri, 9 Jan 2026 09:11:28 +0100
>>>> Thomas Weißschuh <thomas.weissschuh@linutronix.de> wrote:
>>>>
>>>>> On Thu, Jan 08, 2026 at 11:12:29PM +0100, Bernd Schubert wrote:
>>>>>>
>>>>>>
>>>>>> On 1/5/26 13:09, Arnd Bergmann wrote:
>>>>>>> On Mon, Jan 5, 2026, at 09:50, Bernd Schubert wrote:
>>>> ...
>>>>>>> I don't think we'll find a solution that won't break somewhere,
>>>>>>> and using the kernel-internal types at least makes it consistent
>>>>>>> with the rest of the kernel headers.
>>>>>>>
>>>>>>> If we can rely on compiling with a modern compiler (any version of
>>>>>>> clang, or gcc-4.5+), it predefines a __UINT64_TYPE__ macro that
>>>>>>> could be used for custom typedef:
>>>>>>>
>>>>>>> #ifdef __UINT64_TYPE__
>>>>>>> typedef __UINT64_TYPE__ fuse_u64;
>>>>>>> typedef __INT64_TYPE__ fuse_s64;
>>>>>>> typedef __UINT32_TYPE__ fuse_u32;
>>>>>>> typedef __INT32_TYPE__ fuse_s32;
>>>>>>> ...
>>>>>>> #else
>>>>>>> #include <stdint.h>
>>>>>>> typedef uint64_t fuse_u64;
>>>>>>> typedef int64_t fuse_s64;
>>>>>>> typedef uint32_t fuse_u32;
>>>>>>> typedef int32_t fuse_s32;
>>>>>>> ...
>>>>>>> #endif
>>>>>>
>>>>>> I personally like this version.
>>>>>
>>>>> Ack, I'll use this. Although I am not sure why uint64_t and __UINT64_TYPE__
>>>>> should be guaranteed to be identical.
>>>>
>>>> Indeed, on 64bit the 64bit types could be 'long' or 'long long'.
>>>> You've still got the problem of the correct printf format specifier.
>>>> On 32bit the 32bit types could be 'int' or 'long'.
>>>>
>>>> stdint.h 'solves' the printf issue with the (horrid) PRIu64 defines.
>>>> But I don't know how you find out what gcc's format checking uses.
>>>> So you might have to cast all the values to underlying C types in
>>>> order pass the printf format checks.
>>>> At which point you might as well have:
>>>> typedef unsigned int fuse_u32;
>>>> typedef unsigned long long fuse_u64;
>>>> _Static_assert(sizeof (fuse_u32) == 4 && sizeof (fuse_u64) == 8);
>>>> And then use %x and %llx in the format strings.
>>
>> These changes to format strings are what we are trying to avoid.
>
> Where do PRIu64 (and friends) come from if you don't include stdint.h ?
> I think Linux kernel always uses 'int' and 'long long', but other
> compilation environments might use 'long' for one of them [1].
> So while you can define ABI correct PRIu64 and PRIu32 you can't define
> ones that pass compiler format checking without knowing the underlying
> C types.
libfuse uses PRIu64 and it make heavy usage of stdint.h in general, I
don't think building it in that no-libc environment would work. But that
doesn't mean the header couldn't be included in another lib that works
differently.
Thanks,
Bernd
^ permalink raw reply [flat|nested] 21+ messages in thread
* Re: [PATCH v2] fuse: uapi: use UAPI types
2026-01-09 13:46 ` Bernd Schubert
@ 2026-01-09 19:13 ` David Laight
0 siblings, 0 replies; 21+ messages in thread
From: David Laight @ 2026-01-09 19:13 UTC (permalink / raw)
To: Bernd Schubert
Cc: Thomas Weißschuh, Arnd Bergmann, Miklos Szeredi,
linux-fsdevel, linux-kernel
On Fri, 9 Jan 2026 14:46:02 +0100
Bernd Schubert <bernd@bsbernd.com> wrote:
> On 1/9/26 14:11, David Laight wrote:
> > On Fri, 9 Jan 2026 11:55:30 +0100
> > Thomas Weißschuh <thomas.weissschuh@linutronix.de> wrote:
> >
> >> On Fri, Jan 09, 2026 at 11:45:33AM +0100, Bernd Schubert wrote:
> >>>
> >>>
> >>> On 1/9/26 11:38, David Laight wrote:
> >>>> On Fri, 9 Jan 2026 09:11:28 +0100
> >>>> Thomas Weißschuh <thomas.weissschuh@linutronix.de> wrote:
> >>>>
> >>>>> On Thu, Jan 08, 2026 at 11:12:29PM +0100, Bernd Schubert wrote:
> >>>>>>
> >>>>>>
> >>>>>> On 1/5/26 13:09, Arnd Bergmann wrote:
> >>>>>>> On Mon, Jan 5, 2026, at 09:50, Bernd Schubert wrote:
> >>>> ...
> >>>>>>> I don't think we'll find a solution that won't break somewhere,
> >>>>>>> and using the kernel-internal types at least makes it consistent
> >>>>>>> with the rest of the kernel headers.
> >>>>>>>
> >>>>>>> If we can rely on compiling with a modern compiler (any version of
> >>>>>>> clang, or gcc-4.5+), it predefines a __UINT64_TYPE__ macro that
> >>>>>>> could be used for custom typedef:
> >>>>>>>
> >>>>>>> #ifdef __UINT64_TYPE__
> >>>>>>> typedef __UINT64_TYPE__ fuse_u64;
> >>>>>>> typedef __INT64_TYPE__ fuse_s64;
> >>>>>>> typedef __UINT32_TYPE__ fuse_u32;
> >>>>>>> typedef __INT32_TYPE__ fuse_s32;
> >>>>>>> ...
> >>>>>>> #else
> >>>>>>> #include <stdint.h>
> >>>>>>> typedef uint64_t fuse_u64;
> >>>>>>> typedef int64_t fuse_s64;
> >>>>>>> typedef uint32_t fuse_u32;
> >>>>>>> typedef int32_t fuse_s32;
> >>>>>>> ...
> >>>>>>> #endif
> >>>>>>
> >>>>>> I personally like this version.
> >>>>>
> >>>>> Ack, I'll use this. Although I am not sure why uint64_t and __UINT64_TYPE__
> >>>>> should be guaranteed to be identical.
> >>>>
> >>>> Indeed, on 64bit the 64bit types could be 'long' or 'long long'.
> >>>> You've still got the problem of the correct printf format specifier.
> >>>> On 32bit the 32bit types could be 'int' or 'long'.
> >>>>
> >>>> stdint.h 'solves' the printf issue with the (horrid) PRIu64 defines.
> >>>> But I don't know how you find out what gcc's format checking uses.
> >>>> So you might have to cast all the values to underlying C types in
> >>>> order pass the printf format checks.
> >>>> At which point you might as well have:
> >>>> typedef unsigned int fuse_u32;
> >>>> typedef unsigned long long fuse_u64;
> >>>> _Static_assert(sizeof (fuse_u32) == 4 && sizeof (fuse_u64) == 8);
> >>>> And then use %x and %llx in the format strings.
> >>
> >> These changes to format strings are what we are trying to avoid.
> >
> > Where do PRIu64 (and friends) come from if you don't include stdint.h ?
> > I think Linux kernel always uses 'int' and 'long long', but other
> > compilation environments might use 'long' for one of them [1].
> > So while you can define ABI correct PRIu64 and PRIu32 you can't define
> > ones that pass compiler format checking without knowing the underlying
> > C types.
>
> libfuse uses PRIu64 and it make heavy usage of stdint.h in general, I
> don't think building it in that no-libc environment would work. But that
> doesn't mean the header couldn't be included in another lib that works
> differently.
That means you need to 'fake up' definitions equivalent to those from
stdint.h when it isn't available.
I don't think checking for __UINT64_TYPE__ will work if you need printf
to work - since I don't remember the compiler having anything that will
help you generate a correct PRIu64.
(And I wouldn't like to guarantee that stdint.h always matches the compiler
internal configuration.)
If stdint.h is already included PRIu64 (etc) will be defined and all is fine.
If __KERNEL__ is defined then you can use 'long long' and 'int' (and define
matching PRIu64 if needed for consistency).
Otherwise you need to include stdint.h.
Perhaps you could check '#if defined(__KERNEL__) || defined(__NO_STDINT_H__)
then an environment that doesn't have stdint.h would still compile (with an
extra -D__NO_STDINT_H__ on the command line).
David
>
> Thanks,
> Bernd
^ permalink raw reply [flat|nested] 21+ messages in thread
end of thread, other threads:[~2026-01-09 19:13 UTC | newest]
Thread overview: 21+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2025-12-30 12:10 [PATCH v2] fuse: uapi: use UAPI types Thomas Weißschuh
2025-12-30 21:09 ` Arnd Bergmann
2026-01-02 22:27 ` Bernd Schubert
2026-01-03 12:44 ` Bernd Schubert
2026-01-05 8:40 ` Thomas Weißschuh
2026-01-05 8:50 ` Bernd Schubert
2026-01-05 9:57 ` Thomas Weißschuh
2026-01-05 12:09 ` Arnd Bergmann
2026-01-08 22:12 ` Bernd Schubert
2026-01-09 8:11 ` Thomas Weißschuh
2026-01-09 10:38 ` David Laight
2026-01-09 10:45 ` Bernd Schubert
2026-01-09 10:55 ` Thomas Weißschuh
2026-01-09 11:36 ` Bernd Schubert
2026-01-09 13:11 ` David Laight
2026-01-09 13:46 ` Bernd Schubert
2026-01-09 19:13 ` David Laight
2026-01-08 22:14 ` Bernd Schubert
2026-01-03 14:10 ` David Laight
2026-01-03 16:47 ` Bernd Schubert
2026-01-05 12:45 ` Miklos Szeredi
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