diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2025-07-28 15:24:14 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2025-07-28 15:24:14 -0700 |
commit | 57fcb7d930d8f00f383e995aeebdcd2b416a187a (patch) | |
tree | 3d093cd86721c58408594324ad55bd478922b6fe /fs/ioctl.c | |
parent | cec40a7c80e8b0ef03667708ea2660bc1a99b464 (diff) | |
parent | e85931d1cd699307e6a3f1060cbe4c42748f3fff (diff) |
Merge tag 'vfs-6.17-rc1.fileattr' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull fileattr updates from Christian Brauner:
"This introduces the new file_getattr() and file_setattr() system calls
after lengthy discussions.
Both system calls serve as successors and extensible companions to
the FS_IOC_FSGETXATTR and FS_IOC_FSSETXATTR system calls which have
started to show their age in addition to being named in a way that
makes it easy to conflate them with extended attribute related
operations.
These syscalls allow userspace to set filesystem inode attributes on
special files. One of the usage examples is the XFS quota projects.
XFS has project quotas which could be attached to a directory. All new
inodes in these directories inherit project ID set on parent
directory.
The project is created from userspace by opening and calling
FS_IOC_FSSETXATTR on each inode. This is not possible for special
files such as FIFO, SOCK, BLK etc. Therefore, some inodes are left
with empty project ID. Those inodes then are not shown in the quota
accounting but still exist in the directory. This is not critical but
in the case when special files are created in the directory with
already existing project quota, these new inodes inherit extended
attributes. This creates a mix of special files with and without
attributes. Moreover, special files with attributes don't have a
possibility to become clear or change the attributes. This, in turn,
prevents userspace from re-creating quota project on these existing
files.
In addition, these new system calls allow the implementation of
additional attributes that we couldn't or didn't want to fit into the
legacy ioctls anymore"
* tag 'vfs-6.17-rc1.fileattr' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
fs: tighten a sanity check in file_attr_to_fileattr()
tree-wide: s/struct fileattr/struct file_kattr/g
fs: introduce file_getattr and file_setattr syscalls
fs: prepare for extending file_get/setattr()
fs: make vfs_fileattr_[get|set] return -EOPNOTSUPP
selinux: implement inode_file_[g|s]etattr hooks
lsm: introduce new hooks for setting/getting inode fsxattr
fs: split fileattr related helpers into separate file
Diffstat (limited to 'fs/ioctl.c')
-rw-r--r-- | fs/ioctl.c | 309 |
1 files changed, 0 insertions, 309 deletions
diff --git a/fs/ioctl.c b/fs/ioctl.c index 69107a245b4c..0248cb8db2d3 100644 --- a/fs/ioctl.c +++ b/fs/ioctl.c @@ -453,315 +453,6 @@ out: return ret; } -/** - * fileattr_fill_xflags - initialize fileattr with xflags - * @fa: fileattr pointer - * @xflags: FS_XFLAG_* flags - * - * Set ->fsx_xflags, ->fsx_valid and ->flags (translated xflags). All - * other fields are zeroed. - */ -void fileattr_fill_xflags(struct fileattr *fa, u32 xflags) -{ - memset(fa, 0, sizeof(*fa)); - fa->fsx_valid = true; - fa->fsx_xflags = xflags; - if (fa->fsx_xflags & FS_XFLAG_IMMUTABLE) - fa->flags |= FS_IMMUTABLE_FL; - if (fa->fsx_xflags & FS_XFLAG_APPEND) - fa->flags |= FS_APPEND_FL; - if (fa->fsx_xflags & FS_XFLAG_SYNC) - fa->flags |= FS_SYNC_FL; - if (fa->fsx_xflags & FS_XFLAG_NOATIME) - fa->flags |= FS_NOATIME_FL; - if (fa->fsx_xflags & FS_XFLAG_NODUMP) - fa->flags |= FS_NODUMP_FL; - if (fa->fsx_xflags & FS_XFLAG_DAX) - fa->flags |= FS_DAX_FL; - if (fa->fsx_xflags & FS_XFLAG_PROJINHERIT) - fa->flags |= FS_PROJINHERIT_FL; -} -EXPORT_SYMBOL(fileattr_fill_xflags); - -/** - * fileattr_fill_flags - initialize fileattr with flags - * @fa: fileattr pointer - * @flags: FS_*_FL flags - * - * Set ->flags, ->flags_valid and ->fsx_xflags (translated flags). - * All other fields are zeroed. - */ -void fileattr_fill_flags(struct fileattr *fa, u32 flags) -{ - memset(fa, 0, sizeof(*fa)); - fa->flags_valid = true; - fa->flags = flags; - if (fa->flags & FS_SYNC_FL) - fa->fsx_xflags |= FS_XFLAG_SYNC; - if (fa->flags & FS_IMMUTABLE_FL) - fa->fsx_xflags |= FS_XFLAG_IMMUTABLE; - if (fa->flags & FS_APPEND_FL) - fa->fsx_xflags |= FS_XFLAG_APPEND; - if (fa->flags & FS_NODUMP_FL) - fa->fsx_xflags |= FS_XFLAG_NODUMP; - if (fa->flags & FS_NOATIME_FL) - fa->fsx_xflags |= FS_XFLAG_NOATIME; - if (fa->flags & FS_DAX_FL) - fa->fsx_xflags |= FS_XFLAG_DAX; - if (fa->flags & FS_PROJINHERIT_FL) - fa->fsx_xflags |= FS_XFLAG_PROJINHERIT; -} -EXPORT_SYMBOL(fileattr_fill_flags); - -/** - * vfs_fileattr_get - retrieve miscellaneous file attributes - * @dentry: the object to retrieve from - * @fa: fileattr pointer - * - * Call i_op->fileattr_get() callback, if exists. - * - * Return: 0 on success, or a negative error on failure. - */ -int vfs_fileattr_get(struct dentry *dentry, struct fileattr *fa) -{ - struct inode *inode = d_inode(dentry); - - if (!inode->i_op->fileattr_get) - return -ENOIOCTLCMD; - - return inode->i_op->fileattr_get(dentry, fa); -} -EXPORT_SYMBOL(vfs_fileattr_get); - -/** - * copy_fsxattr_to_user - copy fsxattr to userspace. - * @fa: fileattr pointer - * @ufa: fsxattr user pointer - * - * Return: 0 on success, or -EFAULT on failure. - */ -int copy_fsxattr_to_user(const struct fileattr *fa, struct fsxattr __user *ufa) -{ - struct fsxattr xfa; - - memset(&xfa, 0, sizeof(xfa)); - xfa.fsx_xflags = fa->fsx_xflags; - xfa.fsx_extsize = fa->fsx_extsize; - xfa.fsx_nextents = fa->fsx_nextents; - xfa.fsx_projid = fa->fsx_projid; - xfa.fsx_cowextsize = fa->fsx_cowextsize; - - if (copy_to_user(ufa, &xfa, sizeof(xfa))) - return -EFAULT; - - return 0; -} -EXPORT_SYMBOL(copy_fsxattr_to_user); - -static int copy_fsxattr_from_user(struct fileattr *fa, - struct fsxattr __user *ufa) -{ - struct fsxattr xfa; - - if (copy_from_user(&xfa, ufa, sizeof(xfa))) - return -EFAULT; - - fileattr_fill_xflags(fa, xfa.fsx_xflags); - fa->fsx_extsize = xfa.fsx_extsize; - fa->fsx_nextents = xfa.fsx_nextents; - fa->fsx_projid = xfa.fsx_projid; - fa->fsx_cowextsize = xfa.fsx_cowextsize; - - return 0; -} - -/* - * Generic function to check FS_IOC_FSSETXATTR/FS_IOC_SETFLAGS values and reject - * any invalid configurations. - * - * Note: must be called with inode lock held. - */ -static int fileattr_set_prepare(struct inode *inode, - const struct fileattr *old_ma, - struct fileattr *fa) -{ - int err; - - /* - * The IMMUTABLE and APPEND_ONLY flags can only be changed by - * the relevant capability. - */ - if ((fa->flags ^ old_ma->flags) & (FS_APPEND_FL | FS_IMMUTABLE_FL) && - !capable(CAP_LINUX_IMMUTABLE)) - return -EPERM; - - err = fscrypt_prepare_setflags(inode, old_ma->flags, fa->flags); - if (err) - return err; - - /* - * Project Quota ID state is only allowed to change from within the init - * namespace. Enforce that restriction only if we are trying to change - * the quota ID state. Everything else is allowed in user namespaces. - */ - if (current_user_ns() != &init_user_ns) { - if (old_ma->fsx_projid != fa->fsx_projid) - return -EINVAL; - if ((old_ma->fsx_xflags ^ fa->fsx_xflags) & - FS_XFLAG_PROJINHERIT) - return -EINVAL; - } else { - /* - * Caller is allowed to change the project ID. If it is being - * changed, make sure that the new value is valid. - */ - if (old_ma->fsx_projid != fa->fsx_projid && - !projid_valid(make_kprojid(&init_user_ns, fa->fsx_projid))) - return -EINVAL; - } - - /* Check extent size hints. */ - if ((fa->fsx_xflags & FS_XFLAG_EXTSIZE) && !S_ISREG(inode->i_mode)) - return -EINVAL; - - if ((fa->fsx_xflags & FS_XFLAG_EXTSZINHERIT) && - !S_ISDIR(inode->i_mode)) - return -EINVAL; - - if ((fa->fsx_xflags & FS_XFLAG_COWEXTSIZE) && - !S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode)) - return -EINVAL; - - /* - * It is only valid to set the DAX flag on regular files and - * directories on filesystems. - */ - if ((fa->fsx_xflags & FS_XFLAG_DAX) && - !(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode))) - return -EINVAL; - - /* Extent size hints of zero turn off the flags. */ - if (fa->fsx_extsize == 0) - fa->fsx_xflags &= ~(FS_XFLAG_EXTSIZE | FS_XFLAG_EXTSZINHERIT); - if (fa->fsx_cowextsize == 0) - fa->fsx_xflags &= ~FS_XFLAG_COWEXTSIZE; - - return 0; -} - -/** - * vfs_fileattr_set - change miscellaneous file attributes - * @idmap: idmap of the mount - * @dentry: the object to change - * @fa: fileattr pointer - * - * After verifying permissions, call i_op->fileattr_set() callback, if - * exists. - * - * Verifying attributes involves retrieving current attributes with - * i_op->fileattr_get(), this also allows initializing attributes that have - * not been set by the caller to current values. Inode lock is held - * thoughout to prevent racing with another instance. - * - * Return: 0 on success, or a negative error on failure. - */ -int vfs_fileattr_set(struct mnt_idmap *idmap, struct dentry *dentry, - struct fileattr *fa) -{ - struct inode *inode = d_inode(dentry); - struct fileattr old_ma = {}; - int err; - - if (!inode->i_op->fileattr_set) - return -ENOIOCTLCMD; - - if (!inode_owner_or_capable(idmap, inode)) - return -EPERM; - - inode_lock(inode); - err = vfs_fileattr_get(dentry, &old_ma); - if (!err) { - /* initialize missing bits from old_ma */ - if (fa->flags_valid) { - fa->fsx_xflags |= old_ma.fsx_xflags & ~FS_XFLAG_COMMON; - fa->fsx_extsize = old_ma.fsx_extsize; - fa->fsx_nextents = old_ma.fsx_nextents; - fa->fsx_projid = old_ma.fsx_projid; - fa->fsx_cowextsize = old_ma.fsx_cowextsize; - } else { - fa->flags |= old_ma.flags & ~FS_COMMON_FL; - } - err = fileattr_set_prepare(inode, &old_ma, fa); - if (!err) - err = inode->i_op->fileattr_set(idmap, dentry, fa); - } - inode_unlock(inode); - - return err; -} -EXPORT_SYMBOL(vfs_fileattr_set); - -static int ioctl_getflags(struct file *file, unsigned int __user *argp) -{ - struct fileattr fa = { .flags_valid = true }; /* hint only */ - int err; - - err = vfs_fileattr_get(file->f_path.dentry, &fa); - if (!err) - err = put_user(fa.flags, argp); - return err; -} - -static int ioctl_setflags(struct file *file, unsigned int __user *argp) -{ - struct mnt_idmap *idmap = file_mnt_idmap(file); - struct dentry *dentry = file->f_path.dentry; - struct fileattr fa; - unsigned int flags; - int err; - - err = get_user(flags, argp); - if (!err) { - err = mnt_want_write_file(file); - if (!err) { - fileattr_fill_flags(&fa, flags); - err = vfs_fileattr_set(idmap, dentry, &fa); - mnt_drop_write_file(file); - } - } - return err; -} - -static int ioctl_fsgetxattr(struct file *file, void __user *argp) -{ - struct fileattr fa = { .fsx_valid = true }; /* hint only */ - int err; - - err = vfs_fileattr_get(file->f_path.dentry, &fa); - if (!err) - err = copy_fsxattr_to_user(&fa, argp); - - return err; -} - -static int ioctl_fssetxattr(struct file *file, void __user *argp) -{ - struct mnt_idmap *idmap = file_mnt_idmap(file); - struct dentry *dentry = file->f_path.dentry; - struct fileattr fa; - int err; - - err = copy_fsxattr_from_user(&fa, argp); - if (!err) { - err = mnt_want_write_file(file); - if (!err) { - err = vfs_fileattr_set(idmap, dentry, &fa); - mnt_drop_write_file(file); - } - } - return err; -} - static int ioctl_getfsuuid(struct file *file, void __user *argp) { struct super_block *sb = file_inode(file)->i_sb; |