From: Andrey Albershteyn <aalbe...@redhat.com>
Introduce file_getattr and file_setattr syscalls to manipulate inode
extended attributes/flags. The syscalls take parent directory fd and
path to the child together with struct fsxattr.
This is an alternative to FS_IOC_FSSETXATTR ioctl with a difference
that file don't need to be open as we can reference it with a path
instead of fd. By having this we can manipulated inode extended
attributes not only on regular files but also on special ones. This
is not possible with FS_IOC_FSSETXATTR ioctl as with special files
we can not call ioctl() directly on the filesystem inode using fd.
This patch adds two new syscalls which allows userspace to get/set
extended inode attributes on special files by using parent directory
and a path - *at() like syscall.
CC: linux-...@vger.kernel.org
CC: linux-fsde...@vger.kernel.org
CC: linux-...@vger.kernel.org
Signed-off-by: Andrey Albershteyn <aalbe...@kernel.org>
Acked-by: Arnd Bergmann <a...@arndb.de>
---
arch/alpha/kernel/syscalls/syscall.tbl | 2 +
arch/arm/tools/syscall.tbl | 2 +
arch/arm64/tools/syscall_32.tbl | 2 +
arch/m68k/kernel/syscalls/syscall.tbl | 2 +
arch/microblaze/kernel/syscalls/syscall.tbl | 2 +
arch/mips/kernel/syscalls/syscall_n32.tbl | 2 +
arch/mips/kernel/syscalls/syscall_n64.tbl | 2 +
arch/mips/kernel/syscalls/syscall_o32.tbl | 2 +
arch/parisc/kernel/syscalls/syscall.tbl | 2 +
arch/powerpc/kernel/syscalls/syscall.tbl | 2 +
arch/s390/kernel/syscalls/syscall.tbl | 2 +
arch/sh/kernel/syscalls/syscall.tbl | 2 +
arch/sparc/kernel/syscalls/syscall.tbl | 2 +
arch/x86/entry/syscalls/syscall_32.tbl | 2 +
arch/x86/entry/syscalls/syscall_64.tbl | 2 +
arch/xtensa/kernel/syscalls/syscall.tbl | 2 +
fs/file_attr.c | 119 ++++++++++++++++++++++++++++
include/linux/syscalls.h | 6 ++
include/uapi/asm-generic/unistd.h | 8 +-
include/uapi/linux/fs.h | 3 +
20 files changed, 167 insertions(+), 1 deletion(-)
diff --git a/arch/alpha/kernel/syscalls/syscall.tbl
b/arch/alpha/kernel/syscalls/syscall.tbl
index
2dd6340de6b4efddc406f0c235701c15cf02f650..16dca28ebf17e5df2230f640f3686835dc5a1f76
100644
--- a/arch/alpha/kernel/syscalls/syscall.tbl
+++ b/arch/alpha/kernel/syscalls/syscall.tbl
@@ -507,3 +507,5 @@
575 common listxattrat sys_listxattrat
576 common removexattrat sys_removexattrat
577 common open_tree_attr sys_open_tree_attr
+578 common file_getattr sys_file_getattr
+579 common file_setattr sys_file_setattr
diff --git a/arch/arm/tools/syscall.tbl b/arch/arm/tools/syscall.tbl
index
27c1d5ebcd91c8c296dc6676307f66bfdf4ab78d..b07e699aaa3c2840452109c0004529fc68e153ac
100644
--- a/arch/arm/tools/syscall.tbl
+++ b/arch/arm/tools/syscall.tbl
@@ -482,3 +482,5 @@
465 common listxattrat sys_listxattrat
466 common removexattrat sys_removexattrat
467 common open_tree_attr sys_open_tree_attr
+468 common file_getattr sys_file_getattr
+469 common file_setattr sys_file_setattr
diff --git a/arch/arm64/tools/syscall_32.tbl b/arch/arm64/tools/syscall_32.tbl
index
0765b3a8d6d600d7b9f83182d401d9f80c03476c..8d9088bc577df0c6dba6d5d0c227585283789a3f
100644
--- a/arch/arm64/tools/syscall_32.tbl
+++ b/arch/arm64/tools/syscall_32.tbl
@@ -479,3 +479,5 @@
465 common listxattrat sys_listxattrat
466 common removexattrat sys_removexattrat
467 common open_tree_attr sys_open_tree_attr
+468 common file_getattr sys_file_getattr
+469 common file_setattr sys_file_setattr
diff --git a/arch/m68k/kernel/syscalls/syscall.tbl
b/arch/m68k/kernel/syscalls/syscall.tbl
index
9fe47112c586f152662af38a9a7f90957cb96cf8..f41d38dfbf1382339316f4e3e6e79c75dc2804ec
100644
--- a/arch/m68k/kernel/syscalls/syscall.tbl
+++ b/arch/m68k/kernel/syscalls/syscall.tbl
@@ -467,3 +467,5 @@
465 common listxattrat sys_listxattrat
466 common removexattrat sys_removexattrat
467 common open_tree_attr sys_open_tree_attr
+468 common file_getattr sys_file_getattr
+469 common file_setattr sys_file_setattr
diff --git a/arch/microblaze/kernel/syscalls/syscall.tbl
b/arch/microblaze/kernel/syscalls/syscall.tbl
index
7b6e97828e552d4da90046ddfcd4a55723e522bb..580af574fe733af29ea69f40ae6e902ad2166ab2
100644
--- a/arch/microblaze/kernel/syscalls/syscall.tbl
+++ b/arch/microblaze/kernel/syscalls/syscall.tbl
@@ -473,3 +473,5 @@
465 common listxattrat sys_listxattrat
466 common removexattrat sys_removexattrat
467 common open_tree_attr sys_open_tree_attr
+468 common file_getattr sys_file_getattr
+469 common file_setattr sys_file_setattr
diff --git a/arch/mips/kernel/syscalls/syscall_n32.tbl
b/arch/mips/kernel/syscalls/syscall_n32.tbl
index
aa70e371bb54ab5d9c8dd8923b6ecf9693ee914d..d824ffe9a01496a13194710d5278dcc443e40894
100644
--- a/arch/mips/kernel/syscalls/syscall_n32.tbl
+++ b/arch/mips/kernel/syscalls/syscall_n32.tbl
@@ -406,3 +406,5 @@
465 n32 listxattrat sys_listxattrat
466 n32 removexattrat sys_removexattrat
467 n32 open_tree_attr sys_open_tree_attr
+468 n32 file_getattr sys_file_getattr
+469 n32 file_setattr sys_file_setattr
diff --git a/arch/mips/kernel/syscalls/syscall_n64.tbl
b/arch/mips/kernel/syscalls/syscall_n64.tbl
index
1e8c44c7b61492eabf00c777831e457a7a6e579c..7a7049c2c307885fe8be33aedb503cfe8afbfb24
100644
--- a/arch/mips/kernel/syscalls/syscall_n64.tbl
+++ b/arch/mips/kernel/syscalls/syscall_n64.tbl
@@ -382,3 +382,5 @@
465 n64 listxattrat sys_listxattrat
466 n64 removexattrat sys_removexattrat
467 n64 open_tree_attr sys_open_tree_attr
+468 n64 file_getattr sys_file_getattr
+469 n64 file_setattr sys_file_setattr
diff --git a/arch/mips/kernel/syscalls/syscall_o32.tbl
b/arch/mips/kernel/syscalls/syscall_o32.tbl
index
114a5a1a62302e32dd74d1679ff423a2d57c3c6b..d330274f06010c9f9bf80d55898d0bd38994ef58
100644
--- a/arch/mips/kernel/syscalls/syscall_o32.tbl
+++ b/arch/mips/kernel/syscalls/syscall_o32.tbl
@@ -455,3 +455,5 @@
465 o32 listxattrat sys_listxattrat
466 o32 removexattrat sys_removexattrat
467 o32 open_tree_attr sys_open_tree_attr
+468 o32 file_getattr sys_file_getattr
+469 o32 file_setattr sys_file_setattr
diff --git a/arch/parisc/kernel/syscalls/syscall.tbl
b/arch/parisc/kernel/syscalls/syscall.tbl
index
94df3cb957e9d547d192e8732c0cf23ef2b5ce5d..88a788a7b18d17967019098b33d2be48a430aed3
100644
--- a/arch/parisc/kernel/syscalls/syscall.tbl
+++ b/arch/parisc/kernel/syscalls/syscall.tbl
@@ -466,3 +466,5 @@
465 common listxattrat sys_listxattrat
466 common removexattrat sys_removexattrat
467 common open_tree_attr sys_open_tree_attr
+468 common file_getattr sys_file_getattr
+469 common file_setattr sys_file_setattr
diff --git a/arch/powerpc/kernel/syscalls/syscall.tbl
b/arch/powerpc/kernel/syscalls/syscall.tbl
index
9a084bdb892694bc562f514b55212d167cbac12f..b453e80dfc003796a08f022f6bd44cf76a5f82ab
100644
--- a/arch/powerpc/kernel/syscalls/syscall.tbl
+++ b/arch/powerpc/kernel/syscalls/syscall.tbl
@@ -558,3 +558,5 @@
465 common listxattrat sys_listxattrat
466 common removexattrat sys_removexattrat
467 common open_tree_attr sys_open_tree_attr
+468 common file_getattr sys_file_getattr
+469 common file_setattr sys_file_setattr
diff --git a/arch/s390/kernel/syscalls/syscall.tbl
b/arch/s390/kernel/syscalls/syscall.tbl
index
a4569b96ef06c54ce7aa795d039541c90a38284f..8a6744d658db3986f0ac0fd3c90592cdbd27249c
100644
--- a/arch/s390/kernel/syscalls/syscall.tbl
+++ b/arch/s390/kernel/syscalls/syscall.tbl
@@ -470,3 +470,5 @@
465 common listxattrat sys_listxattrat
sys_listxattrat
466 common removexattrat sys_removexattrat
sys_removexattrat
467 common open_tree_attr sys_open_tree_attr
sys_open_tree_attr
+468 common file_getattr sys_file_getattr
sys_file_getattr
+469 common file_setattr sys_file_setattr
sys_file_setattr
diff --git a/arch/sh/kernel/syscalls/syscall.tbl
b/arch/sh/kernel/syscalls/syscall.tbl
index
52a7652fcff6394b96ace1f3b0ed72250ee5e669..5e9c9eff5539e24113bb757f1e5b51bd7c32864e
100644
--- a/arch/sh/kernel/syscalls/syscall.tbl
+++ b/arch/sh/kernel/syscalls/syscall.tbl
@@ -471,3 +471,5 @@
465 common listxattrat sys_listxattrat
466 common removexattrat sys_removexattrat
467 common open_tree_attr sys_open_tree_attr
+468 common file_getattr sys_file_getattr
+469 common file_setattr sys_file_setattr
diff --git a/arch/sparc/kernel/syscalls/syscall.tbl
b/arch/sparc/kernel/syscalls/syscall.tbl
index
83e45eb6c095a36baaf749927628e6052fe900e6..ebb7d06d1044fa9b113b0a3fe0316c77f48fc3d0
100644
--- a/arch/sparc/kernel/syscalls/syscall.tbl
+++ b/arch/sparc/kernel/syscalls/syscall.tbl
@@ -513,3 +513,5 @@
465 common listxattrat sys_listxattrat
466 common removexattrat sys_removexattrat
467 common open_tree_attr sys_open_tree_attr
+468 common file_getattr sys_file_getattr
+469 common file_setattr sys_file_setattr
diff --git a/arch/x86/entry/syscalls/syscall_32.tbl
b/arch/x86/entry/syscalls/syscall_32.tbl
index
ac007ea00979dc28b0ef7c002a0615ce86dd3101..4877e16da69a50f2225088e556661051dbe3c7a3
100644
--- a/arch/x86/entry/syscalls/syscall_32.tbl
+++ b/arch/x86/entry/syscalls/syscall_32.tbl
@@ -473,3 +473,5 @@
465 i386 listxattrat sys_listxattrat
466 i386 removexattrat sys_removexattrat
467 i386 open_tree_attr sys_open_tree_attr
+468 i386 file_getattr sys_file_getattr
+469 i386 file_setattr sys_file_setattr
diff --git a/arch/x86/entry/syscalls/syscall_64.tbl
b/arch/x86/entry/syscalls/syscall_64.tbl
index
cfb5ca41e30de1a4e073750096f5b51a2ec137d2..92cf0fe2291eb99b536e4de4201aec16b3472094
100644
--- a/arch/x86/entry/syscalls/syscall_64.tbl
+++ b/arch/x86/entry/syscalls/syscall_64.tbl
@@ -391,6 +391,8 @@
465 common listxattrat sys_listxattrat
466 common removexattrat sys_removexattrat
467 common open_tree_attr sys_open_tree_attr
+468 common file_getattr sys_file_getattr
+469 common file_setattr sys_file_setattr
#
# Due to a historical design error, certain syscalls are numbered differently
diff --git a/arch/xtensa/kernel/syscalls/syscall.tbl
b/arch/xtensa/kernel/syscalls/syscall.tbl
index
f657a77314f8667fa019a01e10c84ea270024adc..374e4cb788d8a6d4e1f3358b949ea8b600013e1c
100644
--- a/arch/xtensa/kernel/syscalls/syscall.tbl
+++ b/arch/xtensa/kernel/syscalls/syscall.tbl
@@ -438,3 +438,5 @@
465 common listxattrat sys_listxattrat
466 common removexattrat sys_removexattrat
467 common open_tree_attr sys_open_tree_attr
+468 common file_getattr sys_file_getattr
+469 common file_setattr sys_file_setattr
diff --git a/fs/file_attr.c b/fs/file_attr.c
index
6cd1e820f7b108c12c06654df843104f460b94cf..791a97bb2b612b2a0f2c06b7cfb41bac469ea5d1
100644
--- a/fs/file_attr.c
+++ b/fs/file_attr.c
@@ -3,6 +3,10 @@
#include <linux/security.h>
#include <linux/fscrypt.h>
#include <linux/fileattr.h>
+#include <linux/syscalls.h>
+#include <linux/namei.h>
+
+#include "internal.h"
/**
* fileattr_fill_xflags - initialize fileattr with xflags
@@ -354,3 +358,118 @@ int ioctl_fssetxattr(struct file *file, void __user *argp)
return err;
}
EXPORT_SYMBOL(ioctl_fssetxattr);
+
+SYSCALL_DEFINE5(file_getattr, int, dfd, const char __user *, filename,
+ struct fsxattr __user *, ufsx, size_t, usize,
+ unsigned int, at_flags)
+{
+ struct fileattr fa = {};
+ struct path filepath __free(path_put) = {};
+ int error;
+ unsigned int lookup_flags = 0;
+ struct filename *name;
+ struct fsxattr fsx = {};
+
+ BUILD_BUG_ON(sizeof(struct fsxattr) < FSXATTR_SIZE_VER0);
+ BUILD_BUG_ON(sizeof(struct fsxattr) != FSXATTR_SIZE_LATEST);
+
+ if ((at_flags & ~(AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH)) != 0)
+ return -EINVAL;
+
+ if (!(at_flags & AT_SYMLINK_NOFOLLOW))
+ lookup_flags |= LOOKUP_FOLLOW;
+
+ if (usize > PAGE_SIZE)
+ return -E2BIG;
+
+ if (usize < FSXATTR_SIZE_VER0)
+ return -EINVAL;
+
+ name = getname_maybe_null(filename, at_flags);
+ if (IS_ERR(name))
+ return PTR_ERR(name);
+
+ if (!name && dfd >= 0) {
+ CLASS(fd, f)(dfd);
+
+ filepath = fd_file(f)->f_path;
+ path_get(&filepath);
+ } else {
+ error = filename_lookup(dfd, name, lookup_flags, &filepath,
+ NULL);
+ putname(name);
+ if (error)
+ return error;
+ }
+
+ error = vfs_fileattr_get(filepath.dentry, &fa);
+ if (error)
+ return error;
+
+ fileattr_to_fsxattr(&fa, &fsx);
+ error = copy_struct_to_user(ufsx, usize, &fsx, sizeof(struct fsxattr),
+ NULL);
+
+ return error;
+}
+
+SYSCALL_DEFINE5(file_setattr, int, dfd, const char __user *, filename,
+ struct fsxattr __user *, ufsx, size_t, usize,
+ unsigned int, at_flags)
+{
+ struct fileattr fa;
+ struct path filepath __free(path_put) = {};
+ int error;
+ unsigned int lookup_flags = 0;
+ struct filename *name;
+ struct fsxattr fsx = {};
+
+ BUILD_BUG_ON(sizeof(struct fsxattr) < FSXATTR_SIZE_VER0);
+ BUILD_BUG_ON(sizeof(struct fsxattr) != FSXATTR_SIZE_LATEST);
+
+ if ((at_flags & ~(AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH)) != 0)
+ return -EINVAL;
+
+ if (!(at_flags & AT_SYMLINK_NOFOLLOW))
+ lookup_flags |= LOOKUP_FOLLOW;
+
+ if (usize > PAGE_SIZE)
+ return -E2BIG;
+
+ if (usize < FSXATTR_SIZE_VER0)
+ return -EINVAL;
+
+ error = copy_struct_from_user(&fsx, sizeof(struct fsxattr), ufsx,
usize);
+ if (error)
+ return error;
+
+ error = fsxattr_to_fileattr(&fsx, &fa);
+ if (error)
+ return error;
+
+ name = getname_maybe_null(filename, at_flags);
+ if (IS_ERR(name))
+ return PTR_ERR(name);
+
+ if (!name && dfd >= 0) {
+ CLASS(fd, f)(dfd);
+
+ filepath = fd_file(f)->f_path;
+ path_get(&filepath);
+ } else {
+ error = filename_lookup(dfd, name, lookup_flags, &filepath,
+ NULL);
+ putname(name);
+ if (error)
+ return error;
+ }
+
+ error = mnt_want_write(filepath.mnt);
+ if (!error) {
+ error = vfs_fileattr_set(mnt_idmap(filepath.mnt),
+ filepath.dentry, &fa);
+ mnt_drop_write(filepath.mnt);
+ }
+
+ return error;
+}
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index
e5603cc91963dabb79324d6e9e2274f327311245..f2a747479718f9c93f6a448cdab2e60f7ee87709
100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -371,6 +371,12 @@ asmlinkage long sys_removexattrat(int dfd, const char
__user *path,
asmlinkage long sys_lremovexattr(const char __user *path,
const char __user *name);
asmlinkage long sys_fremovexattr(int fd, const char __user *name);
+asmlinkage long sys_file_getattr(int dfd, const char __user *filename,
+ struct fsxattr __user *ufsx, size_t usize,
+ unsigned int at_flags);
+asmlinkage long sys_file_setattr(int dfd, const char __user *filename,
+ struct fsxattr __user *ufsx, size_t usize,
+ unsigned int at_flags);
asmlinkage long sys_getcwd(char __user *buf, unsigned long size);
asmlinkage long sys_eventfd2(unsigned int count, int flags);
asmlinkage long sys_epoll_create1(int flags);
diff --git a/include/uapi/asm-generic/unistd.h
b/include/uapi/asm-generic/unistd.h
index
2892a45023af6d3eb941623d4fed04841ab07e02..04e0077fb4c97a4d565da86d3d0d1d243f32336e
100644
--- a/include/uapi/asm-generic/unistd.h
+++ b/include/uapi/asm-generic/unistd.h
@@ -852,8 +852,14 @@ __SYSCALL(__NR_removexattrat, sys_removexattrat)
#define __NR_open_tree_attr 467
__SYSCALL(__NR_open_tree_attr, sys_open_tree_attr)
+/* fs/inode.c */
+#define __NR_file_getattr 468
+__SYSCALL(__NR_file_getattr, sys_file_getattr)
+#define __NR_file_setattr 469
+__SYSCALL(__NR_file_setattr, sys_file_setattr)
+
#undef __NR_syscalls
-#define __NR_syscalls 468
+#define __NR_syscalls 470
/*
* 32 bit systems traditionally used different
diff --git a/include/uapi/linux/fs.h b/include/uapi/linux/fs.h
index
e762e1af650c4bf08766ba7a8ab7a2288e987039..bc1467b44b80e1db3527dd1b70f1a3a3ca7e4484
100644
--- a/include/uapi/linux/fs.h
+++ b/include/uapi/linux/fs.h
@@ -148,6 +148,9 @@ struct fsxattr {
unsigned char fsx_pad[8];
};
+#define FSXATTR_SIZE_VER0 28
+#define FSXATTR_SIZE_LATEST FSXATTR_SIZE_VER0
+
/*
* Flags for the fsx_xflags field
*/
--
2.47.2
