Add provenance time (ptime), indicating the time when a file or directory was created. This is user-settable via file_setattr() and retrievable via statx(2) (using STATX_PTIME) or file_getattr(). The semantics of when to preserve this new timestamp are the same as mtime, the idea being that there is a correspondence like this: ctime <-> btime mtime <-> ptime so every operation (copying, moving, ...) that currently preserves mtime should also preserve ptime. Furthermore, in order to avoid the legacy FS_IOC_FSSETXATTR accepting FS_XFLAG_PTIME, add an FS_FILE_ATTR_XFLAGS_MASK mask to support new xflags, and use it in fileattr_to_file_attr()/file_attr_to_fileattr() to allow ptime to be used with the file_setattr()/file_getattr() syscalls. [ This is a re-implementation of the initial patch[1] by Sean Smith , following the advice[2] from Darrick J. Wong of using file_setattr() instead of updating utimensat() ] [1]: https://lore.kernel.org/20260405195007.1306-2-DefendTheDisabled@gmail.com [2]: https://lore.kernel.org/20260407014129.GC6192@frogsfrogsfrogs Assisted-by: Gemini:3.8-flash-high antigravity-cli-1.4.7 Signed-off-by: koraynilay --- fs/file_attr.c | 29 +++++++++++++++++++++++++++-- fs/stat.c | 2 ++ include/linux/fileattr.h | 5 +++++ include/linux/stat.h | 1 + include/uapi/linux/fs.h | 8 +++++++- include/uapi/linux/stat.h | 7 ++++++- 6 files changed, 48 insertions(+), 4 deletions(-) diff --git a/fs/file_attr.c b/fs/file_attr.c index 833e03810b24..9c1dfdba6b4d 100644 --- a/fs/file_attr.c +++ b/fs/file_attr.c @@ -102,7 +102,7 @@ EXPORT_SYMBOL(vfs_fileattr_get); static void fileattr_to_file_attr(const struct file_kattr *fa, struct file_attr *fattr) { - __u32 mask = FS_XFLAGS_MASK; + __u32 mask = FS_FILE_ATTR_XFLAGS_MASK; memset(fattr, 0, sizeof(struct file_attr)); fattr->fa_xflags = fa->fsx_xflags & mask; @@ -110,6 +110,8 @@ static void fileattr_to_file_attr(const struct file_kattr *fa, fattr->fa_nextents = fa->fsx_nextents; fattr->fa_projid = fa->fsx_projid; fattr->fa_cowextsize = fa->fsx_cowextsize; + fattr->fa_ptime_sec = fa->fsx_ptime.tv_sec; + fattr->fa_ptime_nsec = fa->fsx_ptime.tv_nsec; } /** @@ -141,15 +143,20 @@ EXPORT_SYMBOL(copy_fsxattr_to_user); static int file_attr_to_fileattr(const struct file_attr *fattr, struct file_kattr *fa) { - __u64 mask = FS_XFLAGS_MASK; + __u64 mask = FS_FILE_ATTR_XFLAGS_MASK; if (fattr->fa_xflags & ~mask) return -EINVAL; + if (fattr->fa_pad != 0) + return -EINVAL; + fileattr_fill_xflags(fa, fattr->fa_xflags & ~FS_XFLAG_RDONLY_MASK); fa->fsx_extsize = fattr->fa_extsize; fa->fsx_projid = fattr->fa_projid; fa->fsx_cowextsize = fattr->fa_cowextsize; + fa->fsx_ptime.tv_sec = fattr->fa_ptime_sec; + fa->fsx_ptime.tv_nsec = fattr->fa_ptime_nsec; return 0; } @@ -232,6 +239,16 @@ static int fileattr_set_prepare(struct inode *inode, !S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode)) return -EINVAL; + if (fa->fsx_xflags & FS_XFLAG_PTIME) { + if (IS_IMMUTABLE(inode) || IS_APPEND(inode)) + return -EPERM; + + if ((unsigned long)fa->fsx_ptime.tv_nsec >= NSEC_PER_SEC) + return -EINVAL; + + fa->fsx_ptime = timestamp_truncate(fa->fsx_ptime, inode); + } + /* * It is only valid to set the DAX flag on regular files and * directories on filesystems. @@ -293,6 +310,7 @@ int vfs_fileattr_set(const struct mnt_idmap *idmap, struct dentry *dentry, fa->fsx_nextents = old_ma.fsx_nextents; fa->fsx_projid = old_ma.fsx_projid; fa->fsx_cowextsize = old_ma.fsx_cowextsize; + fa->fsx_ptime = old_ma.fsx_ptime; } else { fa->flags |= old_ma.flags & ~FS_COMMON_FL; } @@ -423,6 +441,10 @@ SYSCALL_DEFINE5(file_getattr, int, dfd, const char __user *, filename, return error; fileattr_to_file_attr(&fa, &fattr); + + if (usize < FILE_ATTR_SIZE_VER1) + fattr.fa_xflags &= ~FS_XFLAG_PTIME; + error = copy_struct_to_user(ufattr, usize, &fattr, sizeof(struct file_attr), NULL); @@ -459,6 +481,9 @@ SYSCALL_DEFINE5(file_setattr, int, dfd, const char __user *, filename, if (error) return error; + if ((fattr.fa_xflags & FS_XFLAG_PTIME) && usize < FILE_ATTR_SIZE_VER1) + return -EINVAL; + error = file_attr_to_fileattr(&fattr, &fa); if (error) return error; diff --git a/fs/stat.c b/fs/stat.c index a2e63c6c45b7..e426f41253f6 100644 --- a/fs/stat.c +++ b/fs/stat.c @@ -728,6 +728,8 @@ cp_statx(const struct kstat *stat, struct statx __user *buffer) tmp.stx_ctime.tv_nsec = stat->ctime.tv_nsec; tmp.stx_mtime.tv_sec = stat->mtime.tv_sec; tmp.stx_mtime.tv_nsec = stat->mtime.tv_nsec; + tmp.stx_ptime.tv_sec = stat->ptime.tv_sec; + tmp.stx_ptime.tv_nsec = stat->ptime.tv_nsec; tmp.stx_rdev_major = MAJOR(stat->rdev); tmp.stx_rdev_minor = MINOR(stat->rdev); tmp.stx_dev_major = MAJOR(stat->dev); diff --git a/include/linux/fileattr.h b/include/linux/fileattr.h index 09e32b84e02a..0b93f9609284 100644 --- a/include/linux/fileattr.h +++ b/include/linux/fileattr.h @@ -35,6 +35,10 @@ (FS_XFLAG_COMMON | FS_XFLAG_RDONLY_MASK | FS_XFLAG_VALUES_MASK | \ FS_XFLAG_DIRONLY_MASK | FS_XFLAG_MISC_MASK) +/* Flags only for fa_ fields */ +#define FS_FILE_ATTR_XFLAGS_MASK \ + (FS_XFLAGS_MASK | FS_XFLAG_PTIME) + /* * Merged interface for miscellaneous file attributes. 'flags' originates from * ext* and 'fsx_flags' from xfs. There's some overlap between the two, which @@ -49,6 +53,7 @@ struct file_kattr { u32 fsx_nextents; /* nextents field value (get) */ u32 fsx_projid; /* project identifier (get/set) */ u32 fsx_cowextsize; /* CoW extsize field value (get/set)*/ + struct timespec64 fsx_ptime; /* provenance (settable birth) time */ /* selectors: */ bool flags_valid:1; bool fsx_valid:1; diff --git a/include/linux/stat.h b/include/linux/stat.h index 9c5709132862..69d2ecfd1bf2 100644 --- a/include/linux/stat.h +++ b/include/linux/stat.h @@ -48,6 +48,7 @@ struct kstat { struct timespec64 mtime; struct timespec64 ctime; struct timespec64 btime; /* File creation time */ + struct timespec64 ptime; /* File provenance (user-settable creation) time */ u64 blocks; u64 mnt_id; u64 change_cookie; diff --git a/include/uapi/linux/fs.h b/include/uapi/linux/fs.h index a46c33692aa2..c00e72fcfa3e 100644 --- a/include/uapi/linux/fs.h +++ b/include/uapi/linux/fs.h @@ -229,10 +229,14 @@ struct file_attr { __u32 fa_nextents; /* nextents field value (get) */ __u32 fa_projid; /* project identifier (get/set) */ __u32 fa_cowextsize; /* CoW extsize field value (get/set) */ + __s64 fa_ptime_sec; /* provenance (settable birth) time (seconds) */ + __u32 fa_ptime_nsec; /* provenance (settable birth) time (nanoseconds) */ + __u32 fa_pad; }; #define FILE_ATTR_SIZE_VER0 24 -#define FILE_ATTR_SIZE_LATEST FILE_ATTR_SIZE_VER0 +#define FILE_ATTR_SIZE_VER1 40 +#define FILE_ATTR_SIZE_LATEST FILE_ATTR_SIZE_VER1 /* * Flags for the fsx_xflags field @@ -261,6 +265,8 @@ struct file_attr { */ #define FS_XFLAG_CASEFOLD 0x00040000 /* case-insensitive lookups */ #define FS_XFLAG_CASENONPRESERVING 0x00080000 /* case not preserved */ + +#define FS_XFLAG_PTIME 0x00100000 /* provenance time */ #define FS_XFLAG_HASATTR 0x80000000 /* no DIFLAG for this */ /* the read-only stuff doesn't really belong here, but any other place is diff --git a/include/uapi/linux/stat.h b/include/uapi/linux/stat.h index 1686861aae20..f3a1013ba022 100644 --- a/include/uapi/linux/stat.h +++ b/include/uapi/linux/stat.h @@ -187,7 +187,11 @@ struct statx { __u32 __spare2[1]; /* 0xc0 */ - __u64 __spare3[8]; /* Spare space for future expansion */ + /* Data provenance (creation) time */ + struct statx_timestamp stx_ptime; + + /* 0xd0 */ + __u64 __spare3[6]; /* Spare space for future expansion */ /* 0x100 */ }; @@ -219,6 +223,7 @@ struct statx { #define STATX_SUBVOL 0x00008000U /* Want/got stx_subvol */ #define STATX_WRITE_ATOMIC 0x00010000U /* Want/got atomic_write_* fields */ #define STATX_DIO_READ_ALIGN 0x00020000U /* Want/got dio read alignment info */ +#define STATX_PTIME 0x00040000U /* Want/got stx_ptime */ #define STATX__RESERVED 0x80000000U /* Reserved for future struct statx expansion */ -- 2.56.0 Implement provenance time (ptime) in Btrfs, as introduced in the previous commit ("vfs: add provenance time (ptime)"). Update the on-disk format by claiming 12 bytes from the reserved[] space in btrfs_inode_item, putting ptime before other timestamps. Also add the fileattr_has_fsx_mask() helper to include/linux/fileattr.h to let filesystems check for unsupported xflags while allowing supported ones (like ptime). This helper can be used in the same way as fileattr_has_fsx(). Assisted-by: Gemini:3.8-flash-high antigravity-cli-1.4.7 Signed-off-by: koraynilay --- fs/btrfs/btrfs_inode.h | 4 ++++ fs/btrfs/delayed-inode.c | 6 ++++++ fs/btrfs/inode.c | 17 ++++++++++++++++- fs/btrfs/ioctl.c | 12 +++++++++++- fs/btrfs/print-tree.c | 1 + fs/btrfs/tree-log.c | 3 +++ include/linux/fileattr.h | 22 +++++++++++++++++++--- include/uapi/linux/btrfs_tree.h | 3 ++- 8 files changed, 62 insertions(+), 6 deletions(-) diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h index 0782f917fccc..c9822340567a 100644 --- a/fs/btrfs/btrfs_inode.h +++ b/fs/btrfs/btrfs_inode.h @@ -332,6 +332,10 @@ struct btrfs_inode { u64 i_otime_sec; u32 i_otime_nsec; + /* File *data* creation (provenance) time. */ + s64 i_ptime_sec; + u32 i_ptime_nsec; + /* Hook into fs_info->delayed_iputs */ struct list_head delayed_iput; diff --git a/fs/btrfs/delayed-inode.c b/fs/btrfs/delayed-inode.c index 333ce8b52489..eef73ebb4a52 100644 --- a/fs/btrfs/delayed-inode.c +++ b/fs/btrfs/delayed-inode.c @@ -1932,6 +1932,9 @@ static void fill_stack_inode_item(struct btrfs_trans_handle *trans, btrfs_set_stack_timespec_sec(&inode_item->otime, inode->i_otime_sec); btrfs_set_stack_timespec_nsec(&inode_item->otime, inode->i_otime_nsec); + + btrfs_set_stack_timespec_sec(&inode_item->ptime, inode->i_ptime_sec); + btrfs_set_stack_timespec_nsec(&inode_item->ptime, inode->i_ptime_nsec); } int btrfs_fill_inode(struct btrfs_inode *inode, u32 *rdev) @@ -1981,6 +1984,9 @@ int btrfs_fill_inode(struct btrfs_inode *inode, u32 *rdev) inode->i_otime_sec = btrfs_stack_timespec_sec(&inode_item->otime); inode->i_otime_nsec = btrfs_stack_timespec_nsec(&inode_item->otime); + inode->i_ptime_sec = btrfs_stack_timespec_sec(&inode_item->ptime); + inode->i_ptime_nsec = btrfs_stack_timespec_nsec(&inode_item->ptime); + vfs_inode->i_generation = inode->generation; if (S_ISDIR(vfs_inode->i_mode)) inode->index_cnt = (u64)-1; diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index abaa33471456..88515a276925 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -4057,6 +4057,9 @@ static int btrfs_read_locked_inode(struct btrfs_inode *inode, struct btrfs_path inode->i_otime_sec = btrfs_timespec_sec(leaf, &inode_item->otime); inode->i_otime_nsec = btrfs_timespec_nsec(leaf, &inode_item->otime); + inode->i_ptime_sec = btrfs_timespec_sec(leaf, &inode_item->ptime); + inode->i_ptime_nsec = btrfs_timespec_nsec(leaf, &inode_item->ptime); + inode_set_bytes(vfs_inode, btrfs_inode_nbytes(leaf, inode_item)); inode->generation = btrfs_inode_generation(leaf, inode_item); inode->last_trans = btrfs_inode_transid(leaf, inode_item); @@ -4249,6 +4252,9 @@ static void fill_inode_item(struct btrfs_trans_handle *trans, btrfs_set_timespec_sec(leaf, &item->otime, BTRFS_I(inode)->i_otime_sec); btrfs_set_timespec_nsec(leaf, &item->otime, BTRFS_I(inode)->i_otime_nsec); + btrfs_set_timespec_sec(leaf, &item->ptime, BTRFS_I(inode)->i_ptime_sec); + btrfs_set_timespec_nsec(leaf, &item->ptime, BTRFS_I(inode)->i_ptime_nsec); + btrfs_set_inode_nbytes(leaf, item, inode_get_bytes(inode)); btrfs_set_inode_generation(leaf, item, BTRFS_I(inode)->generation); btrfs_set_inode_sequence(leaf, item, inode_peek_iversion(inode)); @@ -5988,6 +5994,8 @@ static struct btrfs_inode *new_simple_dir(struct inode *dir, inode_set_atime_to_ts(vfs_inode, inode_get_atime(dir)); inode->i_otime_sec = ts.tv_sec; inode->i_otime_nsec = ts.tv_nsec; + inode->i_ptime_sec = ts.tv_sec; + inode->i_ptime_nsec = ts.tv_nsec; vfs_inode->i_uid = dir->i_uid; vfs_inode->i_gid = dir->i_gid; @@ -6714,6 +6722,8 @@ int btrfs_create_new_inode(struct btrfs_trans_handle *trans, ts = simple_inode_init_ts(inode); BTRFS_I(inode)->i_otime_sec = ts.tv_sec; BTRFS_I(inode)->i_otime_nsec = ts.tv_nsec; + BTRFS_I(inode)->i_ptime_sec = ts.tv_sec; + BTRFS_I(inode)->i_ptime_nsec = ts.tv_nsec; /* * We're going to fill the inode item now, so at this point the inode @@ -8048,6 +8058,9 @@ struct inode *btrfs_alloc_inode(struct super_block *sb) ei->i_otime_sec = 0; ei->i_otime_nsec = 0; + ei->i_ptime_sec = 0; + ei->i_ptime_nsec = 0; + inode = &ei->vfs_inode; btrfs_extent_map_tree_init(&ei->extent_tree); @@ -8186,9 +8199,11 @@ static int btrfs_getattr(const struct mnt_idmap *idmap, u32 blocksize = btrfs_sb(inode->i_sb)->sectorsize; u32 bi_flags = BTRFS_I(inode)->flags; - stat->result_mask |= STATX_BTIME; + stat->result_mask |= (STATX_BTIME | STATX_PTIME); stat->btime.tv_sec = BTRFS_I(inode)->i_otime_sec; stat->btime.tv_nsec = BTRFS_I(inode)->i_otime_nsec; + stat->ptime.tv_sec = BTRFS_I(inode)->i_ptime_sec; + stat->ptime.tv_nsec = BTRFS_I(inode)->i_ptime_nsec; if (bi_flags & BTRFS_INODE_APPEND) stat->attributes |= STATX_ATTR_APPEND; if (bi_flags & BTRFS_INODE_COMPRESS) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index f3e2afe221be..48598a99bddb 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -275,6 +275,9 @@ int btrfs_fileattr_get(struct dentry *dentry, struct file_kattr *fa) const struct btrfs_inode *inode = BTRFS_I(d_inode(dentry)); fileattr_fill_flags(fa, btrfs_inode_flags_to_fsflags(inode)); + fa->fsx_ptime.tv_sec = inode->i_ptime_sec; + fa->fsx_ptime.tv_nsec = inode->i_ptime_nsec; + fa->fsx_xflags |= FS_XFLAG_PTIME; return 0; } @@ -294,7 +297,10 @@ int btrfs_fileattr_set(const struct mnt_idmap *idmap, if (btrfs_root_readonly(root)) return -EROFS; - if (fileattr_has_fsx(fa)) + /* We now support FS_XFLAG_PTIME, so exclude it from the unsupported + * check + */ + if (fileattr_has_fsx_mask(fa, FS_XFLAG_PTIME)) return -EOPNOTSUPP; fsflags = btrfs_mask_fsflags_for_type(&inode->vfs_inode, fa->flags); @@ -436,6 +442,10 @@ int btrfs_fileattr_set(const struct mnt_idmap *idmap, } update_flags: + if (fa->fsx_xflags & FS_XFLAG_PTIME) { + inode->i_ptime_sec = fa->fsx_ptime.tv_sec; + inode->i_ptime_nsec = fa->fsx_ptime.tv_nsec; + } inode->flags = inode_flags; btrfs_update_inode_mapping_flags(inode); btrfs_sync_inode_flags_to_i_flags(inode); diff --git a/fs/btrfs/print-tree.c b/fs/btrfs/print-tree.c index 53e726119ca7..ba385d0ed9ed 100644 --- a/fs/btrfs/print-tree.c +++ b/fs/btrfs/print-tree.c @@ -263,6 +263,7 @@ static void print_inode_item(const struct extent_buffer *eb, int i) print_timespec(eb, &ii->ctime, "\t\tctime ", "\n"); print_timespec(eb, &ii->mtime, "\t\tmtime ", "\n"); print_timespec(eb, &ii->otime, "\t\totime ", "\n"); + print_timespec(eb, &ii->ptime, "\t\tptime ", "\n"); } static void print_dir_item(const struct extent_buffer *eb, int i) diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c index 1d9dfb63fc5a..72a4a92b40b9 100644 --- a/fs/btrfs/tree-log.c +++ b/fs/btrfs/tree-log.c @@ -4631,6 +4631,9 @@ static void fill_inode_item(struct btrfs_trans_handle *trans, btrfs_set_timespec_sec(leaf, &item->otime, inode->i_otime_sec); btrfs_set_timespec_nsec(leaf, &item->otime, inode->i_otime_nsec); + btrfs_set_timespec_sec(leaf, &item->ptime, inode->i_ptime_sec); + btrfs_set_timespec_nsec(leaf, &item->ptime, inode->i_ptime_nsec); + /* * We do not need to set the nbytes field, in fact during a fast fsync * its value may not even be correct, since a fast fsync does not wait diff --git a/include/linux/fileattr.h b/include/linux/fileattr.h index 0b93f9609284..f45377fdaf38 100644 --- a/include/linux/fileattr.h +++ b/include/linux/fileattr.h @@ -64,6 +64,24 @@ int copy_fsxattr_to_user(const struct file_kattr *fa, struct fsxattr __user *ufa void fileattr_fill_xflags(struct file_kattr *fa, u32 xflags); void fileattr_fill_flags(struct file_kattr *fa, u32 flags); + +/** + * fileattr_has_fsx_mask - check for extended flags/attributes + * @fa: fileattr pointer + * @allowed_xflags_mask: additional xflags permitted + * + * Return: true if any attributes are present that are not represented in + * ->flags or @allowed_xflags_mask. + */ +static inline bool fileattr_has_fsx_mask(const struct file_kattr *fa, + u32 allowed_xflags_mask) +{ + return fa->fsx_valid && + ((fa->fsx_xflags & ~(FS_XFLAG_COMMON | allowed_xflags_mask)) || + fa->fsx_extsize != 0 || fa->fsx_projid != 0 || + fa->fsx_cowextsize != 0); +} + /** * fileattr_has_fsx - check for extended flags/attributes * @fa: fileattr pointer @@ -73,9 +91,7 @@ void fileattr_fill_flags(struct file_kattr *fa, u32 flags); */ static inline bool fileattr_has_fsx(const struct file_kattr *fa) { - return fa->fsx_valid && - ((fa->fsx_xflags & ~FS_XFLAG_COMMON) || fa->fsx_extsize != 0 || - fa->fsx_projid != 0 || fa->fsx_cowextsize != 0); + return fileattr_has_fsx_mask(fa, 0); } int vfs_fileattr_get(struct dentry *dentry, struct file_kattr *fa); diff --git a/include/uapi/linux/btrfs_tree.h b/include/uapi/linux/btrfs_tree.h index 47ee52859b45..c360b3e95f45 100644 --- a/include/uapi/linux/btrfs_tree.h +++ b/include/uapi/linux/btrfs_tree.h @@ -900,7 +900,8 @@ struct btrfs_inode_item { * a little future expansion, for more than this we can * just grow the inode item and version it */ - __le64 reserved[4]; + __le32 reserved[5]; + struct btrfs_timespec ptime; struct btrfs_timespec atime; struct btrfs_timespec ctime; struct btrfs_timespec mtime; -- 2.56.0