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  3. [PATCH v6 0/6] fs: introduce file_getattr and file_setattr syscalls
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[PATCH v6 1/6] fs: split fileattr related helpers into separate file

Andrey Albershteyn posted 6 patches 7 months, 1 week ago
[PATCH v6 1/6] fs: split fileattr related helpers into separate file
Posted by Andrey Albershteyn 7 months, 1 week ago 
From: Andrey Albershteyn <aalbersh@kernel.org>

This patch moves function related to file extended attributes
manipulations to separate file. Refactoring only.

Signed-off-by: Andrey Albershteyn <aalbersh@kernel.org>
---
 fs/Makefile              |   3 +-
 fs/file_attr.c           | 318 +++++++++++++++++++++++++++++++++++++++++++++++
 fs/ioctl.c               | 309 ---------------------------------------------
 include/linux/fileattr.h |   4 +
 4 files changed, 324 insertions(+), 310 deletions(-)

diff --git a/fs/Makefile b/fs/Makefile
index 79c08b914c47..334654f9584b 100644
--- a/fs/Makefile
+++ b/fs/Makefile
@@ -15,7 +15,8 @@ obj-y :=	open.o read_write.o file_table.o super.o \
 		pnode.o splice.o sync.o utimes.o d_path.o \
 		stack.o fs_struct.o statfs.o fs_pin.o nsfs.o \
 		fs_types.o fs_context.o fs_parser.o fsopen.o init.o \
-		kernel_read_file.o mnt_idmapping.o remap_range.o pidfs.o
+		kernel_read_file.o mnt_idmapping.o remap_range.o pidfs.o \
+		file_attr.o
 
 obj-$(CONFIG_BUFFER_HEAD)	+= buffer.o mpage.o
 obj-$(CONFIG_PROC_FS)		+= proc_namespace.o
diff --git a/fs/file_attr.c b/fs/file_attr.c
new file mode 100644
index 000000000000..2910b7047721
--- /dev/null
+++ b/fs/file_attr.c
@@ -0,0 +1,318 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/fs.h>
+#include <linux/security.h>
+#include <linux/fscrypt.h>
+#include <linux/fileattr.h>
+
+/**
+ * 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);
+
+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;
+}
+EXPORT_SYMBOL(ioctl_getflags);
+
+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;
+}
+EXPORT_SYMBOL(ioctl_setflags);
+
+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;
+}
+EXPORT_SYMBOL(ioctl_fsgetxattr);
+
+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;
+}
+EXPORT_SYMBOL(ioctl_fssetxattr);
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 @@ static int ioctl_file_dedupe_range(struct file *file,
 	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;
diff --git a/include/linux/fileattr.h b/include/linux/fileattr.h
index 47c05a9851d0..6030d0bf7ad3 100644
--- a/include/linux/fileattr.h
+++ b/include/linux/fileattr.h
@@ -55,5 +55,9 @@ static inline bool fileattr_has_fsx(const struct fileattr *fa)
 int vfs_fileattr_get(struct dentry *dentry, struct fileattr *fa);
 int vfs_fileattr_set(struct mnt_idmap *idmap, struct dentry *dentry,
 		     struct fileattr *fa);
+int ioctl_getflags(struct file *file, unsigned int __user *argp);
+int ioctl_setflags(struct file *file, unsigned int __user *argp);
+int ioctl_fsgetxattr(struct file *file, void __user *argp);
+int ioctl_fssetxattr(struct file *file, void __user *argp);
 
 #endif /* _LINUX_FILEATTR_H */

-- 
2.47.2
Re: [PATCH v6 1/6] fs: split fileattr related helpers into separate file
Posted by Darrick J. Wong 7 months, 1 week ago 
On Mon, Jun 30, 2025 at 06:20:11PM +0200, Andrey Albershteyn wrote:
> From: Andrey Albershteyn <aalbersh@kernel.org>
> 
> This patch moves function related to file extended attributes
> manipulations to separate file. Refactoring only.
> 
> Signed-off-by: Andrey Albershteyn <aalbersh@kernel.org>

Seems fine to me to move that to a separate file.

Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>

--D

> ---
>  fs/Makefile              |   3 +-
>  fs/file_attr.c           | 318 +++++++++++++++++++++++++++++++++++++++++++++++
>  fs/ioctl.c               | 309 ---------------------------------------------
>  include/linux/fileattr.h |   4 +
>  4 files changed, 324 insertions(+), 310 deletions(-)
> 
> diff --git a/fs/Makefile b/fs/Makefile
> index 79c08b914c47..334654f9584b 100644
> --- a/fs/Makefile
> +++ b/fs/Makefile
> @@ -15,7 +15,8 @@ obj-y :=	open.o read_write.o file_table.o super.o \
>  		pnode.o splice.o sync.o utimes.o d_path.o \
>  		stack.o fs_struct.o statfs.o fs_pin.o nsfs.o \
>  		fs_types.o fs_context.o fs_parser.o fsopen.o init.o \
> -		kernel_read_file.o mnt_idmapping.o remap_range.o pidfs.o
> +		kernel_read_file.o mnt_idmapping.o remap_range.o pidfs.o \
> +		file_attr.o
>  
>  obj-$(CONFIG_BUFFER_HEAD)	+= buffer.o mpage.o
>  obj-$(CONFIG_PROC_FS)		+= proc_namespace.o
> diff --git a/fs/file_attr.c b/fs/file_attr.c
> new file mode 100644
> index 000000000000..2910b7047721
> --- /dev/null
> +++ b/fs/file_attr.c
> @@ -0,0 +1,318 @@
> +// SPDX-License-Identifier: GPL-2.0
> +#include <linux/fs.h>
> +#include <linux/security.h>
> +#include <linux/fscrypt.h>
> +#include <linux/fileattr.h>
> +
> +/**
> + * 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);
> +
> +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;
> +}
> +EXPORT_SYMBOL(ioctl_getflags);
> +
> +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;
> +}
> +EXPORT_SYMBOL(ioctl_setflags);
> +
> +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;
> +}
> +EXPORT_SYMBOL(ioctl_fsgetxattr);
> +
> +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;
> +}
> +EXPORT_SYMBOL(ioctl_fssetxattr);
> 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 @@ static int ioctl_file_dedupe_range(struct file *file,
>  	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;
> diff --git a/include/linux/fileattr.h b/include/linux/fileattr.h
> index 47c05a9851d0..6030d0bf7ad3 100644
> --- a/include/linux/fileattr.h
> +++ b/include/linux/fileattr.h
> @@ -55,5 +55,9 @@ static inline bool fileattr_has_fsx(const struct fileattr *fa)
>  int vfs_fileattr_get(struct dentry *dentry, struct fileattr *fa);
>  int vfs_fileattr_set(struct mnt_idmap *idmap, struct dentry *dentry,
>  		     struct fileattr *fa);
> +int ioctl_getflags(struct file *file, unsigned int __user *argp);
> +int ioctl_setflags(struct file *file, unsigned int __user *argp);
> +int ioctl_fsgetxattr(struct file *file, void __user *argp);
> +int ioctl_fssetxattr(struct file *file, void __user *argp);
>  
>  #endif /* _LINUX_FILEATTR_H */
> 
> -- 
> 2.47.2
> 
>
Re: [PATCH v6 1/6] fs: split fileattr related helpers into separate file
Posted by Jan Kara 7 months, 1 week ago 
On Mon 30-06-25 18:20:11, Andrey Albershteyn wrote:
> From: Andrey Albershteyn <aalbersh@kernel.org>
> 
> This patch moves function related to file extended attributes
> manipulations to separate file. Refactoring only.
> 
> Signed-off-by: Andrey Albershteyn <aalbersh@kernel.org>

Looks good. Feel free to add:

Reviewed-by: Jan Kara <jack@suse.cz>

								Honza

> ---
>  fs/Makefile              |   3 +-
>  fs/file_attr.c           | 318 +++++++++++++++++++++++++++++++++++++++++++++++
>  fs/ioctl.c               | 309 ---------------------------------------------
>  include/linux/fileattr.h |   4 +
>  4 files changed, 324 insertions(+), 310 deletions(-)
> 
> diff --git a/fs/Makefile b/fs/Makefile
> index 79c08b914c47..334654f9584b 100644
> --- a/fs/Makefile
> +++ b/fs/Makefile
> @@ -15,7 +15,8 @@ obj-y :=	open.o read_write.o file_table.o super.o \
>  		pnode.o splice.o sync.o utimes.o d_path.o \
>  		stack.o fs_struct.o statfs.o fs_pin.o nsfs.o \
>  		fs_types.o fs_context.o fs_parser.o fsopen.o init.o \
> -		kernel_read_file.o mnt_idmapping.o remap_range.o pidfs.o
> +		kernel_read_file.o mnt_idmapping.o remap_range.o pidfs.o \
> +		file_attr.o
>  
>  obj-$(CONFIG_BUFFER_HEAD)	+= buffer.o mpage.o
>  obj-$(CONFIG_PROC_FS)		+= proc_namespace.o
> diff --git a/fs/file_attr.c b/fs/file_attr.c
> new file mode 100644
> index 000000000000..2910b7047721
> --- /dev/null
> +++ b/fs/file_attr.c
> @@ -0,0 +1,318 @@
> +// SPDX-License-Identifier: GPL-2.0
> +#include <linux/fs.h>
> +#include <linux/security.h>
> +#include <linux/fscrypt.h>
> +#include <linux/fileattr.h>
> +
> +/**
> + * 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);
> +
> +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;
> +}
> +EXPORT_SYMBOL(ioctl_getflags);
> +
> +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;
> +}
> +EXPORT_SYMBOL(ioctl_setflags);
> +
> +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;
> +}
> +EXPORT_SYMBOL(ioctl_fsgetxattr);
> +
> +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;
> +}
> +EXPORT_SYMBOL(ioctl_fssetxattr);
> 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 @@ static int ioctl_file_dedupe_range(struct file *file,
>  	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;
> diff --git a/include/linux/fileattr.h b/include/linux/fileattr.h
> index 47c05a9851d0..6030d0bf7ad3 100644
> --- a/include/linux/fileattr.h
> +++ b/include/linux/fileattr.h
> @@ -55,5 +55,9 @@ static inline bool fileattr_has_fsx(const struct fileattr *fa)
>  int vfs_fileattr_get(struct dentry *dentry, struct fileattr *fa);
>  int vfs_fileattr_set(struct mnt_idmap *idmap, struct dentry *dentry,
>  		     struct fileattr *fa);
> +int ioctl_getflags(struct file *file, unsigned int __user *argp);
> +int ioctl_setflags(struct file *file, unsigned int __user *argp);
> +int ioctl_fsgetxattr(struct file *file, void __user *argp);
> +int ioctl_fssetxattr(struct file *file, void __user *argp);
>  
>  #endif /* _LINUX_FILEATTR_H */
> 
> -- 
> 2.47.2
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR
Re: [PATCH v6 1/6] fs: split fileattr related helpers into separate file
Posted by Amir Goldstein 7 months, 1 week ago 
On Mon, Jun 30, 2025 at 6:20 PM Andrey Albershteyn <aalbersh@redhat.com> wrote:
>
> From: Andrey Albershteyn <aalbersh@kernel.org>
>
> This patch moves function related to file extended attributes
> manipulations to separate file. Refactoring only.
>
> Signed-off-by: Andrey Albershteyn <aalbersh@kernel.org>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>

> ---
>  fs/Makefile              |   3 +-
>  fs/file_attr.c           | 318 +++++++++++++++++++++++++++++++++++++++++++++++
>  fs/ioctl.c               | 309 ---------------------------------------------
>  include/linux/fileattr.h |   4 +
>  4 files changed, 324 insertions(+), 310 deletions(-)
>
> diff --git a/fs/Makefile b/fs/Makefile
> index 79c08b914c47..334654f9584b 100644
> --- a/fs/Makefile
> +++ b/fs/Makefile
> @@ -15,7 +15,8 @@ obj-y :=      open.o read_write.o file_table.o super.o \
>                 pnode.o splice.o sync.o utimes.o d_path.o \
>                 stack.o fs_struct.o statfs.o fs_pin.o nsfs.o \
>                 fs_types.o fs_context.o fs_parser.o fsopen.o init.o \
> -               kernel_read_file.o mnt_idmapping.o remap_range.o pidfs.o
> +               kernel_read_file.o mnt_idmapping.o remap_range.o pidfs.o \
> +               file_attr.o
>
>  obj-$(CONFIG_BUFFER_HEAD)      += buffer.o mpage.o
>  obj-$(CONFIG_PROC_FS)          += proc_namespace.o
> diff --git a/fs/file_attr.c b/fs/file_attr.c
> new file mode 100644
> index 000000000000..2910b7047721
> --- /dev/null
> +++ b/fs/file_attr.c
> @@ -0,0 +1,318 @@
> +// SPDX-License-Identifier: GPL-2.0
> +#include <linux/fs.h>
> +#include <linux/security.h>
> +#include <linux/fscrypt.h>
> +#include <linux/fileattr.h>
> +
> +/**
> + * 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);
> +
> +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;
> +}
> +EXPORT_SYMBOL(ioctl_getflags);
> +
> +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;
> +}
> +EXPORT_SYMBOL(ioctl_setflags);
> +
> +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;
> +}
> +EXPORT_SYMBOL(ioctl_fsgetxattr);
> +
> +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;
> +}
> +EXPORT_SYMBOL(ioctl_fssetxattr);
> 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 @@ static int ioctl_file_dedupe_range(struct file *file,
>         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;
> diff --git a/include/linux/fileattr.h b/include/linux/fileattr.h
> index 47c05a9851d0..6030d0bf7ad3 100644
> --- a/include/linux/fileattr.h
> +++ b/include/linux/fileattr.h
> @@ -55,5 +55,9 @@ static inline bool fileattr_has_fsx(const struct fileattr *fa)
>  int vfs_fileattr_get(struct dentry *dentry, struct fileattr *fa);
>  int vfs_fileattr_set(struct mnt_idmap *idmap, struct dentry *dentry,
>                      struct fileattr *fa);
> +int ioctl_getflags(struct file *file, unsigned int __user *argp);
> +int ioctl_setflags(struct file *file, unsigned int __user *argp);
> +int ioctl_fsgetxattr(struct file *file, void __user *argp);
> +int ioctl_fssetxattr(struct file *file, void __user *argp);
>
>  #endif /* _LINUX_FILEATTR_H */
>
> --
> 2.47.2
>

Patchew 2.1-devel-b67e4c2

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