From: Andrey Albershteyn <aalbe...@redhat.com>
Introduce getfsxattrat and setfsxattrat 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...@redhat.com>
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/inode.c | 130 ++++++++++++++++++++++++++++
include/linux/syscalls.h | 6 ++
include/uapi/asm-generic/unistd.h | 8 +-
include/uapi/linux/fs.h | 3 +
20 files changed, 178 insertions(+), 1 deletion(-)
diff --git a/arch/alpha/kernel/syscalls/syscall.tbl
b/arch/alpha/kernel/syscalls/syscall.tbl
index
c59d53d6d3f3490f976ca179ddfe02e69265ae4d..4b9e687494c16b60c6fd6ca1dc4d6564706a7e25
100644
--- a/arch/alpha/kernel/syscalls/syscall.tbl
+++ b/arch/alpha/kernel/syscalls/syscall.tbl
@@ -506,3 +506,5 @@
574 common getxattrat sys_getxattrat
575 common listxattrat sys_listxattrat
576 common removexattrat sys_removexattrat
+577 common getfsxattrat sys_getfsxattrat
+578 common setfsxattrat sys_setfsxattrat
diff --git a/arch/arm/tools/syscall.tbl b/arch/arm/tools/syscall.tbl
index
49eeb2ad8dbd8e074c6240417693f23fb328afa8..66466257f3c2debb3e2299f0b608c6740c98cab2
100644
--- a/arch/arm/tools/syscall.tbl
+++ b/arch/arm/tools/syscall.tbl
@@ -481,3 +481,5 @@
464 common getxattrat sys_getxattrat
465 common listxattrat sys_listxattrat
466 common removexattrat sys_removexattrat
+467 common getfsxattrat sys_getfsxattrat
+468 common setfsxattrat sys_setfsxattrat
diff --git a/arch/arm64/tools/syscall_32.tbl b/arch/arm64/tools/syscall_32.tbl
index
69a829912a05eb8a3e21ed701d1030e31c0148bc..9c516118b154811d8d11d5696f32817430320dbf
100644
--- a/arch/arm64/tools/syscall_32.tbl
+++ b/arch/arm64/tools/syscall_32.tbl
@@ -478,3 +478,5 @@
464 common getxattrat sys_getxattrat
465 common listxattrat sys_listxattrat
466 common removexattrat sys_removexattrat
+467 common getfsxattrat sys_getfsxattrat
+468 common setfsxattrat sys_setfsxattrat
diff --git a/arch/m68k/kernel/syscalls/syscall.tbl
b/arch/m68k/kernel/syscalls/syscall.tbl
index
f5ed71f1910d09769c845c2d062d99ee0449437c..159476387f394a92ee5e29db89b118c630372db2
100644
--- a/arch/m68k/kernel/syscalls/syscall.tbl
+++ b/arch/m68k/kernel/syscalls/syscall.tbl
@@ -466,3 +466,5 @@
464 common getxattrat sys_getxattrat
465 common listxattrat sys_listxattrat
466 common removexattrat sys_removexattrat
+467 common getfsxattrat sys_getfsxattrat
+468 common setfsxattrat sys_setfsxattrat
diff --git a/arch/microblaze/kernel/syscalls/syscall.tbl
b/arch/microblaze/kernel/syscalls/syscall.tbl
index
680f568b77f2cbefc3eacb2517f276041f229b1e..a6d59ee740b58cacf823702003cf9bad17c0d3b7
100644
--- a/arch/microblaze/kernel/syscalls/syscall.tbl
+++ b/arch/microblaze/kernel/syscalls/syscall.tbl
@@ -472,3 +472,5 @@
464 common getxattrat sys_getxattrat
465 common listxattrat sys_listxattrat
466 common removexattrat sys_removexattrat
+467 common getfsxattrat sys_getfsxattrat
+468 common setfsxattrat sys_setfsxattrat
diff --git a/arch/mips/kernel/syscalls/syscall_n32.tbl
b/arch/mips/kernel/syscalls/syscall_n32.tbl
index
0b9b7e25b69ad592642f8533bee9ccfe95ce9626..cfe38fcebe1a0279e11751378d3e71c5ec6b6569
100644
--- a/arch/mips/kernel/syscalls/syscall_n32.tbl
+++ b/arch/mips/kernel/syscalls/syscall_n32.tbl
@@ -405,3 +405,5 @@
464 n32 getxattrat sys_getxattrat
465 n32 listxattrat sys_listxattrat
466 n32 removexattrat sys_removexattrat
+467 n32 getfsxattrat sys_getfsxattrat
+468 n32 setfsxattrat sys_setfsxattrat
diff --git a/arch/mips/kernel/syscalls/syscall_n64.tbl
b/arch/mips/kernel/syscalls/syscall_n64.tbl
index
c844cd5cda620b2809a397cdd6f4315ab6a1bfe2..29a0c5974d1aa2f01e33edc0252d75fb97abe230
100644
--- a/arch/mips/kernel/syscalls/syscall_n64.tbl
+++ b/arch/mips/kernel/syscalls/syscall_n64.tbl
@@ -381,3 +381,5 @@
464 n64 getxattrat sys_getxattrat
465 n64 listxattrat sys_listxattrat
466 n64 removexattrat sys_removexattrat
+467 n64 getfsxattrat sys_getfsxattrat
+468 n64 setfsxattrat sys_setfsxattrat
diff --git a/arch/mips/kernel/syscalls/syscall_o32.tbl
b/arch/mips/kernel/syscalls/syscall_o32.tbl
index
349b8aad1159f404103bd2057a1e64e9bf309f18..6c00436807c57c492ba957fcd59af1202231cf80
100644
--- a/arch/mips/kernel/syscalls/syscall_o32.tbl
+++ b/arch/mips/kernel/syscalls/syscall_o32.tbl
@@ -454,3 +454,5 @@
464 o32 getxattrat sys_getxattrat
465 o32 listxattrat sys_listxattrat
466 o32 removexattrat sys_removexattrat
+467 o32 getfsxattrat sys_getfsxattrat
+468 o32 setfsxattrat sys_setfsxattrat
diff --git a/arch/parisc/kernel/syscalls/syscall.tbl
b/arch/parisc/kernel/syscalls/syscall.tbl
index
d9fc94c869657fcfbd7aca1d5f5abc9fae2fb9d8..b3578fac43d6b65167787fcc97d2d09f5a9828e7
100644
--- a/arch/parisc/kernel/syscalls/syscall.tbl
+++ b/arch/parisc/kernel/syscalls/syscall.tbl
@@ -465,3 +465,5 @@
464 common getxattrat sys_getxattrat
465 common listxattrat sys_listxattrat
466 common removexattrat sys_removexattrat
+467 common getfsxattrat sys_getfsxattrat
+468 common setfsxattrat sys_setfsxattrat
diff --git a/arch/powerpc/kernel/syscalls/syscall.tbl
b/arch/powerpc/kernel/syscalls/syscall.tbl
index
d8b4ab78bef076bd50d49b87dea5060fd8c1686a..808045d82c9465c3bfa96b15947546efe5851e9a
100644
--- a/arch/powerpc/kernel/syscalls/syscall.tbl
+++ b/arch/powerpc/kernel/syscalls/syscall.tbl
@@ -557,3 +557,5 @@
464 common getxattrat sys_getxattrat
465 common listxattrat sys_listxattrat
466 common removexattrat sys_removexattrat
+467 common getfsxattrat sys_getfsxattrat
+468 common setfsxattrat sys_setfsxattrat
diff --git a/arch/s390/kernel/syscalls/syscall.tbl
b/arch/s390/kernel/syscalls/syscall.tbl
index
e9115b4d8b635b846e5c9ad6ce229605323723a5..78dfc2c184d4815baf8a9e61c546c9936d58a47c
100644
--- a/arch/s390/kernel/syscalls/syscall.tbl
+++ b/arch/s390/kernel/syscalls/syscall.tbl
@@ -469,3 +469,5 @@
464 common getxattrat sys_getxattrat
sys_getxattrat
465 common listxattrat sys_listxattrat
sys_listxattrat
466 common removexattrat sys_removexattrat
sys_removexattrat
+467 common getfsxattrat sys_getfsxattrat
sys_getfsxattrat
+468 common setfsxattrat sys_setfsxattrat
sys_setfsxattrat
diff --git a/arch/sh/kernel/syscalls/syscall.tbl
b/arch/sh/kernel/syscalls/syscall.tbl
index
c8cad33bf250ea110de37bd1407f5a43ec5e38f2..d5a5c8339f0ed25ea07c4aba90351d352033c8a0
100644
--- a/arch/sh/kernel/syscalls/syscall.tbl
+++ b/arch/sh/kernel/syscalls/syscall.tbl
@@ -470,3 +470,5 @@
464 common getxattrat sys_getxattrat
465 common listxattrat sys_listxattrat
466 common removexattrat sys_removexattrat
+467 common getfsxattrat sys_getfsxattrat
+468 common setfsxattrat sys_setfsxattrat
diff --git a/arch/sparc/kernel/syscalls/syscall.tbl
b/arch/sparc/kernel/syscalls/syscall.tbl
index
727f99d333b304b3db0711953a3d91ece18a28eb..817dcd8603bcbffc47f3f59aa3b74b16486453d0
100644
--- a/arch/sparc/kernel/syscalls/syscall.tbl
+++ b/arch/sparc/kernel/syscalls/syscall.tbl
@@ -512,3 +512,5 @@
464 common getxattrat sys_getxattrat
465 common listxattrat sys_listxattrat
466 common removexattrat sys_removexattrat
+467 common getfsxattrat sys_getfsxattrat
+468 common setfsxattrat sys_setfsxattrat
diff --git a/arch/x86/entry/syscalls/syscall_32.tbl
b/arch/x86/entry/syscalls/syscall_32.tbl
index
4d0fb2fba7e208ae9455459afe11e277321d9f74..b4842c027c5d00c0236b2ba89387c5e2267447bd
100644
--- a/arch/x86/entry/syscalls/syscall_32.tbl
+++ b/arch/x86/entry/syscalls/syscall_32.tbl
@@ -472,3 +472,5 @@
464 i386 getxattrat sys_getxattrat
465 i386 listxattrat sys_listxattrat
466 i386 removexattrat sys_removexattrat
+467 i386 getfsxattrat sys_getfsxattrat
+468 i386 setfsxattrat sys_setfsxattrat
diff --git a/arch/x86/entry/syscalls/syscall_64.tbl
b/arch/x86/entry/syscalls/syscall_64.tbl
index
5eb708bff1c791debd6cfc5322583b2ae53f6437..b6f0a7236aaee624cf9b484239a1068085a8ffe1
100644
--- a/arch/x86/entry/syscalls/syscall_64.tbl
+++ b/arch/x86/entry/syscalls/syscall_64.tbl
@@ -390,6 +390,8 @@
464 common getxattrat sys_getxattrat
465 common listxattrat sys_listxattrat
466 common removexattrat sys_removexattrat
+467 common getfsxattrat sys_getfsxattrat
+468 common setfsxattrat sys_setfsxattrat
#
# 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
37effc1b134eea061f2c350c1d68b4436b65a4dd..425d56be337d1de22f205ac503df61ff86224fee
100644
--- a/arch/xtensa/kernel/syscalls/syscall.tbl
+++ b/arch/xtensa/kernel/syscalls/syscall.tbl
@@ -437,3 +437,5 @@
464 common getxattrat sys_getxattrat
465 common listxattrat sys_listxattrat
466 common removexattrat sys_removexattrat
+467 common getfsxattrat sys_getfsxattrat
+468 common setfsxattrat sys_setfsxattrat
diff --git a/fs/inode.c b/fs/inode.c
index
6b4c77268fc0ecace4ac78a9ca777fbffc277f4a..811debf379ab299f287ed90863277cfda27db30c
100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -23,6 +23,9 @@
#include <linux/rw_hint.h>
#include <linux/seq_file.h>
#include <linux/debugfs.h>
+#include <linux/syscalls.h>
+#include <linux/fileattr.h>
+#include <linux/namei.h>
#include <trace/events/writeback.h>
#define CREATE_TRACE_POINTS
#include <trace/events/timestamp.h>
@@ -2953,3 +2956,130 @@ umode_t mode_strip_sgid(struct mnt_idmap *idmap,
return mode & ~S_ISGID;
}
EXPORT_SYMBOL(mode_strip_sgid);
+
+SYSCALL_DEFINE5(getfsxattrat, int, dfd, const char __user *, filename,
+ struct fsxattr __user *, ufsx, size_t, usize,
+ unsigned int, at_flags)
+{
+ struct fileattr fa = {};
+ struct path filepath;
+ 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 (at_flags & AT_EMPTY_PATH)
+ lookup_flags |= LOOKUP_EMPTY;
+
+ if (usize > PAGE_SIZE)
+ return -E2BIG;
+
+ if (usize < FSXATTR_SIZE_VER0)
+ return -EINVAL;
+
+ name = getname_maybe_null(filename, at_flags);
+ if (!name) {
+ CLASS(fd, f)(dfd);
+
+ if (fd_empty(f))
+ return -EBADF;
+ error = vfs_fileattr_get(file_dentry(fd_file(f)), &fa);
+ } else {
+ error = filename_lookup(dfd, name, lookup_flags, &filepath,
+ NULL);
+ if (error)
+ goto out;
+ error = vfs_fileattr_get(filepath.dentry, &fa);
+ path_put(&filepath);
+ }
+ if (error == -ENOIOCTLCMD)
+ error = -EOPNOTSUPP;
+ if (!error) {
+ fileattr_to_fsxattr(&fa, &fsx);
+ error = copy_struct_to_user(ufsx, usize, &fsx,
+ sizeof(struct fsxattr), NULL);
+ }
+out:
+ putname(name);
+ return error;
+}
+
+SYSCALL_DEFINE5(setfsxattrat, int, dfd, const char __user *, filename,
+ struct fsxattr __user *, ufsx, size_t, usize,
+ unsigned int, at_flags)
+{
+ struct fileattr fa;
+ struct path filepath;
+ int error;
+ unsigned int lookup_flags = 0;
+ struct filename *name;
+ struct mnt_idmap *idmap;
+ struct dentry *dentry;
+ struct vfsmount *mnt;
+ 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 (at_flags & AT_EMPTY_PATH)
+ lookup_flags |= LOOKUP_EMPTY;
+
+ 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;
+
+ fsxattr_to_fileattr(&fsx, &fa);
+
+ name = getname_maybe_null(filename, at_flags);
+ if (!name) {
+ CLASS(fd, f)(dfd);
+
+ if (fd_empty(f))
+ return -EBADF;
+
+ idmap = file_mnt_idmap(fd_file(f));
+ dentry = file_dentry(fd_file(f));
+ mnt = fd_file(f)->f_path.mnt;
+ } else {
+ error = filename_lookup(dfd, name, lookup_flags, &filepath,
+ NULL);
+ if (error)
+ return error;
+
+ idmap = mnt_idmap(filepath.mnt);
+ dentry = filepath.dentry;
+ mnt = filepath.mnt;
+ }
+
+ error = mnt_want_write(mnt);
+ if (!error) {
+ error = vfs_fileattr_set(idmap, dentry, &fa);
+ if (error == -ENOIOCTLCMD)
+ error = -EOPNOTSUPP;
+ mnt_drop_write(mnt);
+ }
+
+ path_put(&filepath);
+ return error;
+}
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index
c6333204d45130eb022f6db460eea34a1f6e91db..e242ea39b3e63a8008bc777764b616fd63bd40c4
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_getfsxattrat(int dfd, const char __user *filename,
+ struct fsxattr __user *ufsx, size_t usize,
+ unsigned int at_flags);
+asmlinkage long sys_setfsxattrat(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
88dc393c2bca38c0fa1b3fae579f7cfe4931223c..50be2e1007bc2779120d05c6e9512a689f86779c
100644
--- a/include/uapi/asm-generic/unistd.h
+++ b/include/uapi/asm-generic/unistd.h
@@ -850,8 +850,14 @@ __SYSCALL(__NR_listxattrat, sys_listxattrat)
#define __NR_removexattrat 466
__SYSCALL(__NR_removexattrat, sys_removexattrat)
+/* fs/inode.c */
+#define __NR_getfsxattrat 467
+__SYSCALL(__NR_getfsxattrat, sys_getfsxattrat)
+#define __NR_setfsxattrat 468
+__SYSCALL(__NR_setfsxattrat, sys_setfsxattrat)
+
#undef __NR_syscalls
-#define __NR_syscalls 467
+#define __NR_syscalls 469
/*
* 32 bit systems traditionally used different
diff --git a/include/uapi/linux/fs.h b/include/uapi/linux/fs.h
index
7539717707337a8cb22396a869baba3bafa08371..aed753e5d50c97da9b895a187fdaecf0477db74b
100644
--- a/include/uapi/linux/fs.h
+++ b/include/uapi/linux/fs.h
@@ -139,6 +139,9 @@ 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
