diff options
| author | Christian Brauner <brauner@kernel.org> | 2025-01-28 11:33:41 +0100 |
|---|---|---|
| committer | Christian Brauner <brauner@kernel.org> | 2025-02-12 12:12:28 +0100 |
| commit | c4a16820d90199409c9bf01c4f794e1e9e8d8fd8 (patch) | |
| tree | b3de182aaedb70d4278e12becfc23a829ffc9a82 | |
| parent | 474f7825d5335798742b92f067e1d22365013107 (diff) | |
| download | net-c4a16820d90199409c9bf01c4f794e1e9e8d8fd8.tar.gz | |
fs: add open_tree_attr()
Add open_tree_attr() which allow to atomically create a detached mount
tree and set mount options on it. If OPEN_TREE_CLONE is used this will
allow the creation of a detached mount with a new set of mount options
without it ever being exposed to userspace without that set of mount
options applied.
Link: https://lore.kernel.org/r/20250128-work-mnt_idmap-update-v2-v1-3-c25feb0d2eb3@kernel.org
Reviewed-by: "Seth Forshee (DigitalOcean)" <sforshee@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
| -rw-r--r-- | arch/alpha/kernel/syscalls/syscall.tbl | 1 | ||||
| -rw-r--r-- | arch/arm/tools/syscall.tbl | 1 | ||||
| -rw-r--r-- | arch/arm64/tools/syscall_32.tbl | 1 | ||||
| -rw-r--r-- | arch/m68k/kernel/syscalls/syscall.tbl | 1 | ||||
| -rw-r--r-- | arch/microblaze/kernel/syscalls/syscall.tbl | 1 | ||||
| -rw-r--r-- | arch/mips/kernel/syscalls/syscall_n32.tbl | 1 | ||||
| -rw-r--r-- | arch/mips/kernel/syscalls/syscall_n64.tbl | 1 | ||||
| -rw-r--r-- | arch/mips/kernel/syscalls/syscall_o32.tbl | 1 | ||||
| -rw-r--r-- | arch/parisc/kernel/syscalls/syscall.tbl | 1 | ||||
| -rw-r--r-- | arch/powerpc/kernel/syscalls/syscall.tbl | 1 | ||||
| -rw-r--r-- | arch/s390/kernel/syscalls/syscall.tbl | 1 | ||||
| -rw-r--r-- | arch/sh/kernel/syscalls/syscall.tbl | 1 | ||||
| -rw-r--r-- | arch/sparc/kernel/syscalls/syscall.tbl | 1 | ||||
| -rw-r--r-- | arch/x86/entry/syscalls/syscall_32.tbl | 1 | ||||
| -rw-r--r-- | arch/x86/entry/syscalls/syscall_64.tbl | 1 | ||||
| -rw-r--r-- | arch/xtensa/kernel/syscalls/syscall.tbl | 1 | ||||
| -rw-r--r-- | fs/namespace.c | 39 | ||||
| -rw-r--r-- | include/linux/syscalls.h | 4 | ||||
| -rw-r--r-- | include/uapi/asm-generic/unistd.h | 4 | ||||
| -rw-r--r-- | scripts/syscall.tbl | 1 |
20 files changed, 63 insertions, 1 deletions
diff --git a/arch/alpha/kernel/syscalls/syscall.tbl b/arch/alpha/kernel/syscalls/syscall.tbl index c59d53d6d3f349..2dd6340de6b4ef 100644 --- a/arch/alpha/kernel/syscalls/syscall.tbl +++ b/arch/alpha/kernel/syscalls/syscall.tbl @@ -506,3 +506,4 @@ 574 common getxattrat sys_getxattrat 575 common listxattrat sys_listxattrat 576 common removexattrat sys_removexattrat +577 common open_tree_attr sys_open_tree_attr diff --git a/arch/arm/tools/syscall.tbl b/arch/arm/tools/syscall.tbl index 49eeb2ad8dbd8e..27c1d5ebcd91c8 100644 --- a/arch/arm/tools/syscall.tbl +++ b/arch/arm/tools/syscall.tbl @@ -481,3 +481,4 @@ 464 common getxattrat sys_getxattrat 465 common listxattrat sys_listxattrat 466 common removexattrat sys_removexattrat +467 common open_tree_attr sys_open_tree_attr diff --git a/arch/arm64/tools/syscall_32.tbl b/arch/arm64/tools/syscall_32.tbl index 69a829912a05eb..0765b3a8d6d600 100644 --- a/arch/arm64/tools/syscall_32.tbl +++ b/arch/arm64/tools/syscall_32.tbl @@ -478,3 +478,4 @@ 464 common getxattrat sys_getxattrat 465 common listxattrat sys_listxattrat 466 common removexattrat sys_removexattrat +467 common open_tree_attr sys_open_tree_attr diff --git a/arch/m68k/kernel/syscalls/syscall.tbl b/arch/m68k/kernel/syscalls/syscall.tbl index f5ed71f1910d09..9fe47112c586f1 100644 --- a/arch/m68k/kernel/syscalls/syscall.tbl +++ b/arch/m68k/kernel/syscalls/syscall.tbl @@ -466,3 +466,4 @@ 464 common getxattrat sys_getxattrat 465 common listxattrat sys_listxattrat 466 common removexattrat sys_removexattrat +467 common open_tree_attr sys_open_tree_attr diff --git a/arch/microblaze/kernel/syscalls/syscall.tbl b/arch/microblaze/kernel/syscalls/syscall.tbl index 680f568b77f2cb..7b6e97828e552d 100644 --- a/arch/microblaze/kernel/syscalls/syscall.tbl +++ b/arch/microblaze/kernel/syscalls/syscall.tbl @@ -472,3 +472,4 @@ 464 common getxattrat sys_getxattrat 465 common listxattrat sys_listxattrat 466 common removexattrat sys_removexattrat +467 common open_tree_attr sys_open_tree_attr diff --git a/arch/mips/kernel/syscalls/syscall_n32.tbl b/arch/mips/kernel/syscalls/syscall_n32.tbl index 0b9b7e25b69ad5..aa70e371bb54ab 100644 --- a/arch/mips/kernel/syscalls/syscall_n32.tbl +++ b/arch/mips/kernel/syscalls/syscall_n32.tbl @@ -405,3 +405,4 @@ 464 n32 getxattrat sys_getxattrat 465 n32 listxattrat sys_listxattrat 466 n32 removexattrat sys_removexattrat +467 n32 open_tree_attr sys_open_tree_attr diff --git a/arch/mips/kernel/syscalls/syscall_n64.tbl b/arch/mips/kernel/syscalls/syscall_n64.tbl index c844cd5cda620b..1e8c44c7b61492 100644 --- a/arch/mips/kernel/syscalls/syscall_n64.tbl +++ b/arch/mips/kernel/syscalls/syscall_n64.tbl @@ -381,3 +381,4 @@ 464 n64 getxattrat sys_getxattrat 465 n64 listxattrat sys_listxattrat 466 n64 removexattrat sys_removexattrat +467 n64 open_tree_attr sys_open_tree_attr diff --git a/arch/mips/kernel/syscalls/syscall_o32.tbl b/arch/mips/kernel/syscalls/syscall_o32.tbl index 349b8aad1159f4..114a5a1a62302e 100644 --- a/arch/mips/kernel/syscalls/syscall_o32.tbl +++ b/arch/mips/kernel/syscalls/syscall_o32.tbl @@ -454,3 +454,4 @@ 464 o32 getxattrat sys_getxattrat 465 o32 listxattrat sys_listxattrat 466 o32 removexattrat sys_removexattrat +467 o32 open_tree_attr sys_open_tree_attr diff --git a/arch/parisc/kernel/syscalls/syscall.tbl b/arch/parisc/kernel/syscalls/syscall.tbl index d9fc94c869657f..94df3cb957e9d5 100644 --- a/arch/parisc/kernel/syscalls/syscall.tbl +++ b/arch/parisc/kernel/syscalls/syscall.tbl @@ -465,3 +465,4 @@ 464 common getxattrat sys_getxattrat 465 common listxattrat sys_listxattrat 466 common removexattrat sys_removexattrat +467 common open_tree_attr sys_open_tree_attr diff --git a/arch/powerpc/kernel/syscalls/syscall.tbl b/arch/powerpc/kernel/syscalls/syscall.tbl index d8b4ab78bef076..9a084bdb892694 100644 --- a/arch/powerpc/kernel/syscalls/syscall.tbl +++ b/arch/powerpc/kernel/syscalls/syscall.tbl @@ -557,3 +557,4 @@ 464 common getxattrat sys_getxattrat 465 common listxattrat sys_listxattrat 466 common removexattrat sys_removexattrat +467 common open_tree_attr sys_open_tree_attr diff --git a/arch/s390/kernel/syscalls/syscall.tbl b/arch/s390/kernel/syscalls/syscall.tbl index e9115b4d8b635b..a4569b96ef06c5 100644 --- a/arch/s390/kernel/syscalls/syscall.tbl +++ b/arch/s390/kernel/syscalls/syscall.tbl @@ -469,3 +469,4 @@ 464 common getxattrat sys_getxattrat sys_getxattrat 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 diff --git a/arch/sh/kernel/syscalls/syscall.tbl b/arch/sh/kernel/syscalls/syscall.tbl index c8cad33bf250ea..52a7652fcff639 100644 --- a/arch/sh/kernel/syscalls/syscall.tbl +++ b/arch/sh/kernel/syscalls/syscall.tbl @@ -470,3 +470,4 @@ 464 common getxattrat sys_getxattrat 465 common listxattrat sys_listxattrat 466 common removexattrat sys_removexattrat +467 common open_tree_attr sys_open_tree_attr diff --git a/arch/sparc/kernel/syscalls/syscall.tbl b/arch/sparc/kernel/syscalls/syscall.tbl index 727f99d333b304..83e45eb6c095a3 100644 --- a/arch/sparc/kernel/syscalls/syscall.tbl +++ b/arch/sparc/kernel/syscalls/syscall.tbl @@ -512,3 +512,4 @@ 464 common getxattrat sys_getxattrat 465 common listxattrat sys_listxattrat 466 common removexattrat sys_removexattrat +467 common open_tree_attr sys_open_tree_attr diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl index 4d0fb2fba7e208..3f0ec87d5db4e2 100644 --- a/arch/x86/entry/syscalls/syscall_32.tbl +++ b/arch/x86/entry/syscalls/syscall_32.tbl @@ -472,3 +472,4 @@ 464 i386 getxattrat sys_getxattrat 465 i386 listxattrat sys_listxattrat 466 i386 removexattrat sys_removexattrat +467 i386 open_tree_attr sys_open_tree_attr diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl index 5eb708bff1c791..cfb5ca41e30de1 100644 --- a/arch/x86/entry/syscalls/syscall_64.tbl +++ b/arch/x86/entry/syscalls/syscall_64.tbl @@ -390,6 +390,7 @@ 464 common getxattrat sys_getxattrat 465 common listxattrat sys_listxattrat 466 common removexattrat sys_removexattrat +467 common open_tree_attr sys_open_tree_attr # # 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 37effc1b134eea..f657a77314f866 100644 --- a/arch/xtensa/kernel/syscalls/syscall.tbl +++ b/arch/xtensa/kernel/syscalls/syscall.tbl @@ -437,3 +437,4 @@ 464 common getxattrat sys_getxattrat 465 common listxattrat sys_listxattrat 466 common removexattrat sys_removexattrat +467 common open_tree_attr sys_open_tree_attr diff --git a/fs/namespace.c b/fs/namespace.c index d2ef1d69839bec..ac4ad746c77056 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -4995,6 +4995,45 @@ SYSCALL_DEFINE5(mount_setattr, int, dfd, const char __user *, path, return err; } +SYSCALL_DEFINE5(open_tree_attr, int, dfd, const char __user *, filename, + unsigned, flags, struct mount_attr __user *, uattr, + size_t, usize) +{ + struct file __free(fput) *file = NULL; + int fd; + + if (!uattr && usize) + return -EINVAL; + + file = vfs_open_tree(dfd, filename, flags); + if (IS_ERR(file)) + return PTR_ERR(file); + + if (uattr) { + int ret; + struct mount_kattr kattr = { + .recurse = !!(flags & AT_RECURSIVE), + }; + + ret = copy_mount_setattr(uattr, usize, &kattr); + if (ret) + return ret; + + ret = do_mount_setattr(&file->f_path, &kattr); + if (ret) + return ret; + + finish_mount_kattr(&kattr); + } + + fd = get_unused_fd_flags(flags & O_CLOEXEC); + if (fd < 0) + return fd; + + fd_install(fd, no_free_ptr(file)); + return fd; +} + int show_path(struct seq_file *m, struct dentry *root) { if (root->d_sb->s_op->show_path) diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index c6333204d45130..079ea1d09d85e6 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -951,6 +951,10 @@ asmlinkage long sys_statx(int dfd, const char __user *path, unsigned flags, asmlinkage long sys_rseq(struct rseq __user *rseq, uint32_t rseq_len, int flags, uint32_t sig); asmlinkage long sys_open_tree(int dfd, const char __user *path, unsigned flags); +asmlinkage long sys_open_tree_attr(int dfd, const char __user *path, + unsigned flags, + struct mount_attr __user *uattr, + size_t usize); asmlinkage long sys_move_mount(int from_dfd, const char __user *from_path, int to_dfd, const char __user *to_path, unsigned int ms_flags); diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h index 88dc393c2bca38..2892a45023af6d 100644 --- a/include/uapi/asm-generic/unistd.h +++ b/include/uapi/asm-generic/unistd.h @@ -849,9 +849,11 @@ __SYSCALL(__NR_getxattrat, sys_getxattrat) __SYSCALL(__NR_listxattrat, sys_listxattrat) #define __NR_removexattrat 466 __SYSCALL(__NR_removexattrat, sys_removexattrat) +#define __NR_open_tree_attr 467 +__SYSCALL(__NR_open_tree_attr, sys_open_tree_attr) #undef __NR_syscalls -#define __NR_syscalls 467 +#define __NR_syscalls 468 /* * 32 bit systems traditionally used different diff --git a/scripts/syscall.tbl b/scripts/syscall.tbl index ebbdb3c42e9f74..580b4e246aecd5 100644 --- a/scripts/syscall.tbl +++ b/scripts/syscall.tbl @@ -407,3 +407,4 @@ 464 common getxattrat sys_getxattrat 465 common listxattrat sys_listxattrat 466 common removexattrat sys_removexattrat +467 common open_tree_attr sys_open_tree_attr |